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Kofotolios I, Bonios MJ, Adamopoulos M, Mourouzis I, Filippatos G, Boletis JN, Marinaki S, Mavroidis M. The Han:SPRD Rat: A Preclinical Model of Polycystic Kidney Disease. Biomedicines 2024; 12:362. [PMID: 38397964 PMCID: PMC10887417 DOI: 10.3390/biomedicines12020362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 01/27/2024] [Accepted: 01/30/2024] [Indexed: 02/25/2024] Open
Abstract
Autosomal Dominant Polycystic Kidney Disease (ADPKD) stands as the most prevalent hereditary renal disorder in humans, ultimately culminating in end-stage kidney disease. Animal models carrying mutations associated with polycystic kidney disease have played an important role in the advancement of ADPKD research. The Han:SPRD rat model, carrying an R823W mutation in the Anks6 gene, is characterized by cyst formation and kidney enlargement. The mutated protein, named Samcystin, is localized in cilia of tubular epithelial cells and seems to be involved in cystogenesis. The homozygous Anks6 mutation leads to end-stage renal disease and death, making it a critical factor in kidney development and function. This review explores the utility of the Han:SPRD rat model, highlighting its phenotypic similarity to human ADPKD. Specifically, we discuss its role in preclinical trials and its importance for investigating the pathogenesis of the disease and developing new therapeutic approaches.
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Affiliation(s)
- Ioannis Kofotolios
- Clinic of Nephrology and Renal Tranplantation, Laiko Hospital, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
- Center of Basic Research, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece (M.M.)
| | - Michael J. Bonios
- Heart Failure and Transplant Unit, Onassis Cardiac Surgery Center, 17674 Athens, Greece;
| | - Markos Adamopoulos
- Center of Basic Research, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece (M.M.)
| | - Iordanis Mourouzis
- Department of Pharmacology, National and Kapodistrian University of Athens, 11527 Athens, Greece;
| | - Gerasimos Filippatos
- Department of Cardiology, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, 12462 Athens, Greece
| | - John N. Boletis
- Clinic of Nephrology and Renal Tranplantation, Laiko Hospital, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Smaragdi Marinaki
- Clinic of Nephrology and Renal Tranplantation, Laiko Hospital, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Manolis Mavroidis
- Center of Basic Research, Biomedical Research Foundation, Academy of Athens, 11527 Athens, Greece (M.M.)
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2
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Pala R, Barui AK, Mohieldin AM, Zhou J, Nauli SM. Folate conjugated nanomedicines for selective inhibition of mTOR signaling in polycystic kidneys at clinically relevant doses. Biomaterials 2023; 302:122329. [PMID: 37722182 PMCID: PMC10836200 DOI: 10.1016/j.biomaterials.2023.122329] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 09/12/2023] [Indexed: 09/20/2023]
Abstract
Although rapamycin is a very effective drug for rodents with polycystic kidney disease (PKD), it is not encouraging in the clinical trials due to the suboptimal dosages compelled by the off-target side effects. We here report the generation, characterization, specificity, functionality, pharmacokinetic, pharmacodynamic and toxicology profiles of novel polycystic kidney-specific-targeting nanoparticles (NPs). We formulated folate-conjugated PLGA-PEG NPs, which can be loaded with multiple drugs, including rapamycin (an mTOR inhibitor) and antioxidant 4-hydroxy-TEMPO (a nephroprotective agent). The NPs increased the efficacy, potency and tolerability of rapamycin resulting in an increased survival rate and improved kidney function by decreasing side effects and reducing biodistribution to other organs in PKD mice. The daily administration of rapamycin-alone (1 mg/kg/day) could now be achieved with a weekly injection of NPs containing rapamycin (379 μg/kg/week). This polycystic kidney-targeting nanotechnology, for the first time, integrated advances in the use of 1) nanoparticles as a delivery cargo, 2) folate for targeting, 3) near-infrared Cy5-fluorophore for in vitro and in vivo live imaging, 4) rapamycin as a pharmacological therapy, and 5) TEMPO as a combinational therapy. The slow sustained-release of rapamycin by polycystic kidney-targeting NPs demonstrates a new era of nanomedicine in treatment for chronic kidney diseases at clinically relevant doses.
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Affiliation(s)
- Rajasekharreddy Pala
- Department of Biomedical and Pharmaceutical Sciences, Chapman University, Irvine, CA, 92618, USA; Marlin Biopharma, Irvine, CA, 92620, USA.
| | - Ayan K Barui
- Department of Biomedical and Pharmaceutical Sciences, Chapman University, Irvine, CA, 92618, USA
| | - Ashraf M Mohieldin
- Department of Biomedical and Pharmaceutical Sciences, Chapman University, Irvine, CA, 92618, USA
| | - Jing Zhou
- Department of Medicine, Harvard Medical School, Boston, MA, 02115, USA
| | - Surya M Nauli
- Department of Biomedical and Pharmaceutical Sciences, Chapman University, Irvine, CA, 92618, USA; Marlin Biopharma, Irvine, CA, 92620, USA.
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Iliuta IA, Song X, Pickel L, Haghighi A, Retnakaran R, Scholey J, Sung HK, Steinberg GR, Pei Y. Shared pathobiology identifies AMPK as a therapeutic target for obesity and autosomal dominant polycystic kidney disease. Front Mol Biosci 2022; 9:962933. [PMID: 36106024 PMCID: PMC9467623 DOI: 10.3389/fmolb.2022.962933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 07/21/2022] [Indexed: 12/02/2022] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is the most common Mendelian kidney disease, affecting approximately one in 1,000 births and accounting for 5% of end-stage kidney disease in developed countries. The pathophysiology of ADPKD is strongly linked to metabolic dysregulation, which may be secondary to defective polycystin function. Overweight and obesity are highly prevalent in patients with ADPKD and constitute an independent risk factor for progression. Recent studies have highlighted reduced AMP-activated protein kinase (AMPK) activity, increased mammalian target of rapamycin (mTOR) signaling, and mitochondrial dysfunction as shared pathobiology between ADPKD and overweight/obesity. Notably, mTOR and AMPK are two diametrically opposed sensors of energy metabolism that regulate cell growth and proliferation. However, treatment with the current generation of mTOR inhibitors is poorly tolerated due to their toxicity, making clinical translation difficult. By contrast, multiple preclinical and clinical studies have shown that pharmacological activation of AMPK provides a promising approach to treat ADPKD. In this narrative review, we summarize the pleiotropic functions of AMPK as a regulator of cellular proliferation, macromolecule metabolism, and mitochondrial biogenesis, and discuss the potential for pharmacological activation of AMPK to treat ADPKD and obesity-related kidney disease.
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Affiliation(s)
- Ioan-Andrei Iliuta
- Division of Nephrology, Department of Medicine, University Health Network and University of Toronto, Toronto, ON, Canada
| | - Xuewen Song
- Division of Nephrology, Department of Medicine, University Health Network and University of Toronto, Toronto, ON, Canada
| | - Lauren Pickel
- Translational Medicine Program, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Amirreza Haghighi
- Division of Nephrology, Department of Medicine, University Health Network and University of Toronto, Toronto, ON, Canada
- Division of Genetics, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Ravi Retnakaran
- Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, ON, Canada
| | - James Scholey
- Division of Nephrology, Department of Medicine, University Health Network and University of Toronto, Toronto, ON, Canada
| | - Hoon-Ki Sung
- Translational Medicine Program, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Gregory R. Steinberg
- Department of Medicine, Centre for Metabolism, Obesity, and Diabetes Research, McMaster University, Hamilton, ON, Canada
| | - York Pei
- Division of Nephrology, Department of Medicine, University Health Network and University of Toronto, Toronto, ON, Canada
- *Correspondence: York Pei,
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Oto OA, Edelstein CL. The Pathophysiology of Left Ventricular Hypertrophy, beyond Hypertension, in Autosomal Dominant Polycystic Kidney Disease. Nephron Clin Pract 2022; 148:215-223. [PMID: 35896062 DOI: 10.1159/000525944] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 07/04/2022] [Indexed: 11/19/2022] Open
Abstract
Heart disease is one of the leading causes of death in autosomal dominant polycystic kidney disease (ADPKD) patients. Left ventricular hypertrophy (LVH) is an early and severe complication in ADPKD patients. Two decades ago, the prevalence of LVH on echocardiography in hypertensive ADPKD patients was shown to be as high as 46%. Recent studies using cardiac magnetic resonance imaging have shown that the prevalence of LVH in ADPKD patients may be lower. The true prevalence of LVH in ADPKD patients is controversial. There is evidence that factors other than hypertension contribute to LVH in ADPKD patients. Studies have shown that young normotensive ADPKD adults and children have a higher left ventricular mass index compared to controls and that the prevalence of LVH is high in patients with ADPKD whose blood pressure is well controlled. Polycystin-1 (PC-1) and polycystin-2 (PC-2) control intracellular signaling pathways that can influence cardiac function. Perturbations of PC-1 or PC-2 in the heart can lead to profound changes in cardiac structure and function independently of kidney function or blood pressure. PC-1 can influence mammalian target of rapamycin and mitophagy and PC-2 can influence autophagy, processes that play a role in LVH. Polymorphisms in the angiotensin-converting enzyme gene may play a role in LVH in ADPKD. This review will detail the pathophysiology of LVH, beyond hypertension, in ADPKD.
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Affiliation(s)
- Ozgur A Oto
- Division of Renal Diseases and Hypertension, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA,
| | - Charles L Edelstein
- Division of Renal Diseases and Hypertension, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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Pharmacological Effects of Panduratin A on Renal Cyst Development in In Vitro and In Vivo Models of Polycystic Kidney Disease. Int J Mol Sci 2022; 23:ijms23084328. [PMID: 35457146 PMCID: PMC9024631 DOI: 10.3390/ijms23084328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/06/2022] [Accepted: 04/11/2022] [Indexed: 12/04/2022] Open
Abstract
Renal cyst expansion in polycystic kidney disease (PKD) involves abnormalities in both cyst-lining-cell proliferation and fluid accumulation. Suppression of these processes may retard the progression of PKD. Evidence suggests that the activation of 5' AMP-activated protein kinase (AMPK) inhibits cystic fibrosis transmembrane conductance regulator (CFTR)-mediated chloride secretion, leading to reduced progression of PKD. Here we investigated the pharmacological effects of panduratin A, a bioactive compound known as an AMPK activator, on CFTR-mediated chloride secretion and renal cyst development using in vitro and animal models of PKD. We demonstrated that AMPK was activated in immortalized normal renal cells and autosomal dominant polycystic kidney disease (ADPKD) cells following treatment with panduratin A. Treatment with panduratin A reduced the number of renal cyst colonies corresponding with a decrease in cell proliferation and phosphorylated p70/S6K, a downstream target of mTOR signaling. Additionally, panduratin A slowed cyst expansion via inhibition of the protein expression and transport function of CFTR. In heterozygous Han:Sprague-Dawley (Cy/+) rats, an animal model of PKD, intraperitoneal administration of panduratin A (25 mg/kg BW) for 5 weeks significantly decreased the kidney weight per body weight ratios and the cystic index. Panduratin A also reduced collagen deposition in renal tissue. Intraperitoneal administration of panduratin A caused abdominal bleeding and reduced body weight. However, 25 mg/kg BW of panduratin A via oral administration in the PCK rats, another non-orthologous PKD model, showed a significant decrease in the cystic index without severe adverse effects, indicating that the route of administration is critical in preventing adverse effects while still slowing disease progression. These findings reveal that panduratin A might hold therapeutic properties for the treatment of PKD.
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Caplan MJ. AMPK and Polycystic Kidney Disease Drug Development: An Interesting Off-Target Target. Front Med (Lausanne) 2022; 9:753418. [PMID: 35174190 PMCID: PMC8841847 DOI: 10.3389/fmed.2022.753418] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 01/10/2022] [Indexed: 11/20/2022] Open
Abstract
Autosomal Dominant Polycystic Kidney Disease is a genetic disease that causes dramatic perturbations of both renal tissue architecture and of a multitude of cellular signaling pathways. The relationship between the products of the genes whose mutations cause polycystic kidney disease and these signaling pathways remains difficult to determine. It is clear, however, that cellular metabolism is dramatically altered in cells that are affected by polycystic kidney disease mutations. Adenosine monophosphate-stimulated protein kinase is a master regulator of cellular energy use and generation pathways whose activity appears to be perturbed in cells affected by polycystic kidney disease. Furthermore, modulation of this enzyme's activity may constitute a promising approach for the development of new therapeutics for polycystic kidney disease.
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Reciprocal Regulation between Primary Cilia and mTORC1. Genes (Basel) 2020; 11:genes11060711. [PMID: 32604881 PMCID: PMC7349257 DOI: 10.3390/genes11060711] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 06/22/2020] [Accepted: 06/24/2020] [Indexed: 12/11/2022] Open
Abstract
In quiescent cells, primary cilia function as a mechanosensor that converts mechanic signals into chemical activities. This unique organelle plays a critical role in restricting mechanistic target of rapamycin complex 1 (mTORC1) signaling, which is essential for quiescent cells to maintain their quiescence. Multiple mechanisms have been identified that mediate the inhibitory effect of primary cilia on mTORC1 signaling. These mechanisms depend on several tumor suppressor proteins localized within the ciliary compartment, including liver kinase B1 (LKB1), AMP-activated protein kinase (AMPK), polycystin-1, and polycystin-2. Conversely, changes in mTORC1 activity are able to affect ciliogenesis and stability indirectly through autophagy. In this review, we summarize recent advances in our understanding of the reciprocal regulation of mTORC1 and primary cilia.
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Bhatia D, Choi ME. Autophagy in kidney disease: Advances and therapeutic potential. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 172:107-133. [PMID: 32620239 DOI: 10.1016/bs.pmbts.2020.01.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Autophagy is a highly conserved intracellular catabolic process for the degradation of cytoplasmic components that has recently gained increasing attention for its importance in kidney diseases. It is indispensable for the maintenance of kidney homeostasis both in physiological and pathological conditions. Investigations utilizing various kidney cell-specific conditional autophagy-related gene knockouts have facilitated the advancement in understanding of the role of autophagy in the kidney. Recent findings are raising the possibility that defective autophagy exerts a critical role in different pathological conditions of the kidney. An emerging body of evidence reveals that autophagy exhibits cytoprotective functions in both glomerular and tubular compartments of the kidney, suggesting the upregulation of autophagy as an attractive therapeutic strategy. However, there is also accumulating evidence that autophagy could be deleterious, which presents a formidable challenge in developing therapeutic strategies targeting autophagy. Here, we review the recent advances in research on the role of autophagy during different pathological conditions, including acute kidney injury (AKI), focusing on sepsis, ischemia-reperfusion injury, cisplatin, and heavy metal-induced AKI. We also discuss the role of autophagy in chronic kidney disease (CKD) focusing on the pathogenesis of tubulointerstitial fibrosis, podocytopathies including focal segmental glomerulosclerosis, diabetic nephropathy, IgA nephropathy, membranous nephropathy, HIV-associated nephropathy, and polycystic kidney disease.
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Affiliation(s)
- Divya Bhatia
- Division of Nephrology and Hypertension, Joan and Sanford I. Weill Department of Medicine, NewYork-Presbyterian Hospital, Weill Cornell Medicine, New York, NY, United States
| | - Mary E Choi
- Division of Nephrology and Hypertension, Joan and Sanford I. Weill Department of Medicine, NewYork-Presbyterian Hospital, Weill Cornell Medicine, New York, NY, United States.
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9
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Chu H, Shillingford JM, Reddy JA, Westrick E, Nelson M, Wang EZ, Parker N, Felten AE, Vaughn JF, Xu LC, Lu YJ, Vlahov IR, Leamon CP. Detecting Functional and Accessible Folate Receptor Expression in Cancer and Polycystic Kidneys. Mol Pharm 2019; 16:3985-3995. [PMID: 31356752 DOI: 10.1021/acs.molpharmaceut.9b00624] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Folate-based small molecule drug conjugates (SMDCs) are currently under development and have shown promising preclinical and clinical results against various cancers and polycystic kidney disease. Two requisites for response to a folate-based SMDC are (i) folate receptor alpha (FRα) protein is expressed in the diseased tissues, and (ii) FRα in those tissues is accessible and functionally competent to bind systemically administered SMDCs. Here we report on the development of a small molecule reporter conjugate (SMRC), called EC2220, which is composed of a folate ligand for FRα binding, a multilysine containing linker that can cross-link to FRα in the presence of formaldehyde fixation, and a small hapten (fluorescein) used for immunohistochemical detection. Data show that EC2220 produces a far greater IHC signal in FRα-positive tissues over that produced with EC17, a folate-fluorescein SMRC that is released from the formaldehyde-denatured FRα protein. Furthermore, the extent of the EC2220 IHC signal was proportional to the level of FRα expression. This EC2220-based assay was qualified both in vitro and in vivo using normal tissue, cancer tissue, and polycystic kidneys. Overall, EC2220 is a sensitive and effective reagent for evaluating functional and accessible receptor expression in vitro and in vivo.
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Affiliation(s)
- Haiyan Chu
- Endocyte, Inc. , 3000 Kent Avenue, Suite A1-100 , West Lafayette , Indiana 47906 , United States
| | - Jonathan M Shillingford
- Endocyte, Inc. , 3000 Kent Avenue, Suite A1-100 , West Lafayette , Indiana 47906 , United States
| | - Joseph A Reddy
- Endocyte, Inc. , 3000 Kent Avenue, Suite A1-100 , West Lafayette , Indiana 47906 , United States
| | - Elaine Westrick
- Endocyte, Inc. , 3000 Kent Avenue, Suite A1-100 , West Lafayette , Indiana 47906 , United States
| | - Melissa Nelson
- Endocyte, Inc. , 3000 Kent Avenue, Suite A1-100 , West Lafayette , Indiana 47906 , United States
| | - Emilia Z Wang
- Endocyte, Inc. , 3000 Kent Avenue, Suite A1-100 , West Lafayette , Indiana 47906 , United States
| | - Nikki Parker
- Endocyte, Inc. , 3000 Kent Avenue, Suite A1-100 , West Lafayette , Indiana 47906 , United States
| | - Albert E Felten
- Endocyte, Inc. , 3000 Kent Avenue, Suite A1-100 , West Lafayette , Indiana 47906 , United States
| | - Jeremy F Vaughn
- Endocyte, Inc. , 3000 Kent Avenue, Suite A1-100 , West Lafayette , Indiana 47906 , United States
| | - Le-Cun Xu
- Endocyte, Inc. , 3000 Kent Avenue, Suite A1-100 , West Lafayette , Indiana 47906 , United States
| | - Yingjuan J Lu
- Endocyte, Inc. , 3000 Kent Avenue, Suite A1-100 , West Lafayette , Indiana 47906 , United States
| | - Iontcho R Vlahov
- Endocyte, Inc. , 3000 Kent Avenue, Suite A1-100 , West Lafayette , Indiana 47906 , United States
| | - Christopher P Leamon
- Endocyte, Inc. , 3000 Kent Avenue, Suite A1-100 , West Lafayette , Indiana 47906 , United States
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Metabolism and mitochondria in polycystic kidney disease research and therapy. Nat Rev Nephrol 2019; 14:678-687. [PMID: 30120380 DOI: 10.1038/s41581-018-0051-1] [Citation(s) in RCA: 134] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common, potentially lethal, monogenic diseases and is caused predominantly by mutations in polycystic kidney disease 1 (PKD1) and PKD2, which encode polycystin 1 (PC1) and PC2, respectively. Over the decades-long course of the disease, patients develop large fluid-filled renal cysts that impair kidney function, leading to end-stage renal disease in ~50% of patients. Despite the identification of numerous dysregulated pathways in ADPKD, the molecular mechanisms underlying the renal dysfunction from mutations in PKD genes and the physiological functions of the polycystin proteins are still unclear. Alterations in cell metabolism have emerged in the past decade as a hallmark of ADPKD. ADPKD cells shift their mode of energy production from oxidative phosphorylation to alternative pathways, such as glycolysis. In addition, the polycystins seem to play regulatory roles in modulating mechanisms and machinery related to energy production and utilization, including AMPK, PPARα, PGC1α, calcium signalling at mitochondria-associated membranes, mTORC1, cAMP and CFTR-mediated ion transport as well as the expression of crucial components of the mitochondrial energy production apparatus. In this Review, we explore these metabolic changes and discuss in detail the relationship between energy metabolism and ADPKD pathogenesis and identify potential therapeutic targets.
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Sárközy M, Gáspár R, Zvara Á, Siska A, Kővári B, Szűcs G, Márványkövi F, Kovács MG, Diószegi P, Bodai L, Zsindely N, Pipicz M, Gömöri K, Kiss K, Bencsik P, Cserni G, Puskás LG, Földesi I, Thum T, Bátkai S, Csont T. Chronic kidney disease induces left ventricular overexpression of the pro-hypertrophic microRNA-212. Sci Rep 2019; 9:1302. [PMID: 30718600 PMCID: PMC6362219 DOI: 10.1038/s41598-018-37690-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 12/12/2018] [Indexed: 12/22/2022] Open
Abstract
Chronic kidney disease (CKD) is a public health problem that increases the risk of cardiovascular morbidity and mortality. Heart failure with preserved ejection fraction (HFpEF) characterized by left ventricular hypertrophy (LVH) and diastolic dysfunction is a common cardiovascular complication of CKD. MicroRNA-212 (miR-212) has been demonstrated previously to be a crucial regulator of pathologic LVH in pressure-overload-induced heart failure via regulating the forkhead box O3 (FOXO3)/calcineurin/nuclear factor of activated T-cells (NFAT) pathway. Here we aimed to investigate whether miR-212 and its hypertrophy-associated targets including FOXO3, extracellular signal-regulated kinase 2 (ERK2), and AMP-activated protein kinase (AMPK) play a role in the development of HFpEF in CKD. CKD was induced by 5/6 nephrectomy in male Wistar rats. Echocardiography and histology revealed LVH, fibrosis, preserved systolic function, and diastolic dysfunction in the CKD group as compared to sham-operated animals eight and/or nine weeks later. Left ventricular miR-212 was significantly overexpressed in CKD. However, expressions of FOXO3, AMPK, and ERK2 failed to change significantly at the mRNA or protein level. The protein kinase B (AKT)/FOXO3 and AKT/mammalian target of rapamycin (mTOR) pathways are also proposed regulators of LVH induced by pressure-overload. Interestingly, phospho-AKT/total-AKT ratio was increased in CKD without significantly affecting phosphorylation of FOXO3 or mTOR. In summary, cardiac overexpression of miR-212 in CKD failed to affect its previously implicated hypertrophy-associated downstream targets. Thus, the molecular mechanism of the development of LVH in CKD seems to be independent of the FOXO3, ERK1/2, AMPK, and AKT/mTOR-mediated pathways indicating unique features in this form of LVH.
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Affiliation(s)
- Márta Sárközy
- Metabolic Diseases and Cell Signaling Group, Department of Biochemistry, Interdisciplinary Excellence Centre, University of Szeged, Dóm tér 9, Szeged, H-6720, Hungary.
| | - Renáta Gáspár
- Metabolic Diseases and Cell Signaling Group, Department of Biochemistry, Interdisciplinary Excellence Centre, University of Szeged, Dóm tér 9, Szeged, H-6720, Hungary
| | - Ágnes Zvara
- Laboratory for Functional Genomics, Institute of Genetics, Biological Research Center of the Hungarian Academy of Sciences, Temesvári krt. 62, H-6701, Szeged, Hungary
| | - Andrea Siska
- Department of Laboratory Medicine, Faculty of Medicine, University of Szeged, Semmelweis utca 6, Szeged, H-6725, Hungary
| | - Bence Kővári
- Department of Pathology, University of Szeged, Állomás utca 1, Szeged, H-6725, Hungary
| | - Gergő Szűcs
- Metabolic Diseases and Cell Signaling Group, Department of Biochemistry, Interdisciplinary Excellence Centre, University of Szeged, Dóm tér 9, Szeged, H-6720, Hungary
| | - Fanni Márványkövi
- Metabolic Diseases and Cell Signaling Group, Department of Biochemistry, Interdisciplinary Excellence Centre, University of Szeged, Dóm tér 9, Szeged, H-6720, Hungary
| | - Mónika G Kovács
- Metabolic Diseases and Cell Signaling Group, Department of Biochemistry, Interdisciplinary Excellence Centre, University of Szeged, Dóm tér 9, Szeged, H-6720, Hungary
| | - Petra Diószegi
- Metabolic Diseases and Cell Signaling Group, Department of Biochemistry, Interdisciplinary Excellence Centre, University of Szeged, Dóm tér 9, Szeged, H-6720, Hungary
| | - László Bodai
- Department of Biochemistry and Molecular Biology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, Szeged, H-6726, Hungary
| | - Nóra Zsindely
- Department of Biochemistry and Molecular Biology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, Szeged, H-6726, Hungary
| | - Márton Pipicz
- Metabolic Diseases and Cell Signaling Group, Department of Biochemistry, Interdisciplinary Excellence Centre, University of Szeged, Dóm tér 9, Szeged, H-6720, Hungary
| | - Kamilla Gömöri
- Cardiovascular Research Group, Department of Biochemistry, Faculty of Medicine, University of Szeged, Dóm tér 9, Szeged, H-6720, Hungary
| | - Krisztina Kiss
- Cardiovascular Research Group, Department of Biochemistry, Faculty of Medicine, University of Szeged, Dóm tér 9, Szeged, H-6720, Hungary
| | - Péter Bencsik
- Cardiovascular Research Group, Department of Biochemistry, Faculty of Medicine, University of Szeged, Dóm tér 9, Szeged, H-6720, Hungary
| | - Gábor Cserni
- Department of Pathology, University of Szeged, Állomás utca 1, Szeged, H-6725, Hungary
| | - László G Puskás
- Laboratory for Functional Genomics, Institute of Genetics, Biological Research Center of the Hungarian Academy of Sciences, Temesvári krt. 62, H-6701, Szeged, Hungary
| | - Imre Földesi
- Department of Laboratory Medicine, Faculty of Medicine, University of Szeged, Semmelweis utca 6, Szeged, H-6725, Hungary
| | - Thomas Thum
- IMTTS, Hannover Medical School, Carl-Neuberg Strasse 1, Hannover, 30625, Germany
| | - Sándor Bátkai
- IMTTS, Hannover Medical School, Carl-Neuberg Strasse 1, Hannover, 30625, Germany
| | - Tamás Csont
- Metabolic Diseases and Cell Signaling Group, Department of Biochemistry, Interdisciplinary Excellence Centre, University of Szeged, Dóm tér 9, Szeged, H-6720, Hungary
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Walters HE, Cox LS. mTORC Inhibitors as Broad-Spectrum Therapeutics for Age-Related Diseases. Int J Mol Sci 2018; 19:E2325. [PMID: 30096787 PMCID: PMC6121351 DOI: 10.3390/ijms19082325] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 07/22/2018] [Accepted: 07/30/2018] [Indexed: 02/06/2023] Open
Abstract
Chronological age represents the greatest risk factor for many life-threatening diseases, including neurodegeneration, cancer, and cardiovascular disease; ageing also increases susceptibility to infectious disease. Current efforts to tackle individual diseases may have little impact on the overall healthspan of older individuals, who would still be vulnerable to other age-related pathologies. However, recent progress in ageing research has highlighted the accumulation of senescent cells with chronological age as a probable underlying cause of pathological ageing. Cellular senescence is an essentially irreversible proliferation arrest mechanism that has important roles in development, wound healing, and preventing cancer, but it may limit tissue function and cause widespread inflammation with age. The serine/threonine kinase mTOR (mechanistic target of rapamycin) is a regulatory nexus that is heavily implicated in both ageing and senescence. Excitingly, a growing body of research has highlighted rapamycin and other mTOR inhibitors as promising treatments for a broad spectrum of age-related pathologies, including neurodegeneration, cancer, immunosenescence, osteoporosis, rheumatoid arthritis, age-related blindness, diabetic nephropathy, muscular dystrophy, and cardiovascular disease. In this review, we assess the use of mTOR inhibitors to treat age-related pathologies, discuss possible molecular mechanisms of action where evidence is available, and consider strategies to minimize undesirable side effects. We also emphasize the urgent need for reliable, non-invasive biomarkers of senescence and biological ageing to better monitor the efficacy of any healthy ageing therapy.
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Affiliation(s)
- Hannah E Walters
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
| | - Lynne S Cox
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
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Zhu P, Sieben CJ, Xu X, Harris PC, Lin X. Autophagy activators suppress cystogenesis in an autosomal dominant polycystic kidney disease model. Hum Mol Genet 2017; 26:158-172. [PMID: 28007903 DOI: 10.1093/hmg/ddw376] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 10/27/2016] [Indexed: 01/08/2023] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in either PKD1 or PKD2. It is one of the most common heritable human diseases with eventual development of renal failure; however, effective treatment is lacking. While inhibition of mechanistic target of rapamycin (mTOR) effectively slows cyst expansions in animal models, results from clinical studies are controversial, prompting further mechanistic studies of mTOR-based therapy. Here, we aim to establish autophagy, a downstream pathway of mTOR, as a new therapeutic target for PKD. We generated zebrafish mutants for pkd1 and noted cystic kidney and mTOR activation in pkd1a mutants, suggesting a conserved ADPKD model. Further assessment of the mutants revealed impaired autophagic flux, which was conserved in kidney epithelial cells derived from both Pkd1-null mice and ADPKD patients. We found that inhibition of autophagy by knocking down the core autophagy protein Atg5 promotes cystogenesis, while activation of autophagy using a specific inducer Beclin-1 peptide ameliorates cysts in the pkd1a model. Treatment with compound autophagy activators, including mTOR-dependent rapamycin as well as mTOR-independent carbamazepine and minoxidil, markedly attenuated cyst formation and restored kidney function. Finally, we showed that combination treatment with low doses of rapamycin and carbamazepine was able to attenuate cyst formation as effectively as a single treatment with a high dose of rapamycin alone. In summary, our results suggested a modifying effect of autophagy on ADPKD, established autophagy activation as a novel therapy for ADPKD, and presented zebrafish as an efficient vertebrate model for developing PKD therapeutic strategies.
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Affiliation(s)
- Ping Zhu
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA
| | - Cynthia J Sieben
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA
| | - Xiaolei Xu
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA.,Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, USA
| | - Peter C Harris
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA
| | - Xueying Lin
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA
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14
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Molinari E, Sayer JA. Emerging treatments and personalised medicine for ciliopathies associated with cystic kidney disease. Expert Opin Orphan Drugs 2017. [DOI: 10.1080/21678707.2017.1372282] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Elisa Molinari
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - John A. Sayer
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
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Lushchak O, Strilbytska O, Piskovatska V, Storey KB, Koliada A, Vaiserman A. The role of the TOR pathway in mediating the link between nutrition and longevity. Mech Ageing Dev 2017; 164:127-138. [DOI: 10.1016/j.mad.2017.03.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Revised: 02/23/2017] [Accepted: 03/13/2017] [Indexed: 01/13/2023]
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Yamamoto J, Nishio S, Hattanda F, Nakazawa D, Kimura T, Sata M, Makita M, Ishikawa Y, Atsumi T. Branched-chain amino acids enhance cyst development in autosomal dominant polycystic kidney disease. Kidney Int 2017; 92:377-387. [PMID: 28341273 DOI: 10.1016/j.kint.2017.01.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 01/03/2017] [Accepted: 01/05/2017] [Indexed: 02/06/2023]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is characterized by the progressive development of kidney and liver cysts. The mammalian target of rapamycin (mTOR) cascade is one of the important pathways regulating cyst growth in ADPKD. Branched-chain amino acids (BCAAs), including leucine, play a crucial role to activate mTOR pathway. Therefore, we administered BCAA dissolved in the drinking water to Pkd1flox/flox:Mx1-Cre (cystic) mice from four to 22 weeks of age after polyinosinic-polycytidylic acid-induced conditional Pkd1 knockout at two weeks of age. The BCAA group showed significantly greater kidney/body weight ratio and higher cystic index in both the kidney and liver compared to the placebo-treated mice. We found that the L-type amino acid transporter 1 that facilitates BCAA entry into cells is strongly expressed in cells lining the cysts. We also found increased cyst-lining cell proliferation and upregulation of mTOR and mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathways in the BCAA group. In vitro, we cultured renal epithelial cell lines from Pkd1 null mice with or without leucine. Leucine was found to stimulate cell proliferation, as well as activate mTOR and MAPK/ERK pathways in these cells. Thus, BCAA accelerated disease progression by mTOR and MAPK/ERK pathways. Hence, BCAA may be harmful to patients with ADPKD.
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Affiliation(s)
- Junya Yamamoto
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Saori Nishio
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
| | - Fumihiko Hattanda
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Daigo Nakazawa
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Toru Kimura
- Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Tokyo, Japan
| | - Michio Sata
- Liver Cancer Research Division, Kurume University, Kurume, Japan
| | - Minoru Makita
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Yasunobu Ishikawa
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Tatsuya Atsumi
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
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Sweeney WE, Avner ED. Emerging Therapies for Childhood Polycystic Kidney Disease. Front Pediatr 2017; 5:77. [PMID: 28473970 PMCID: PMC5395658 DOI: 10.3389/fped.2017.00077] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 03/30/2017] [Indexed: 12/28/2022] Open
Abstract
Cystic kidney diseases comprise a varied collection of hereditary disorders, where renal cysts comprise a major element of their pleiotropic phenotype. In pediatric patients, the term polycystic kidney disease (PKD) commonly refers to two specific hereditary diseases, autosomal recessive polycystic kidney disease (ARPKD) and autosomal dominant polycystic kidney disease (ADPKD). Remarkable progress has been made in understanding the complex molecular and cellular mechanisms of renal cyst formation in ARPKD and ADPKD. One of the most important discoveries is that both the genes and proteins products of ARPKD and ADPKD interact in a complex network of genetic and functional interactions. These interactions and the shared phenotypic abnormalities of ARPKD and ADPKD, the "cystic phenotypes" suggest that many of the therapies developed and tested for ADPKD may be effective in ARPKD as well. Successful therapeutic interventions for childhood PKD will, therefore, be guided by knowledge of these molecular interactions, as well as a number of clinical parameters, such as the stage of the disease and the rate of disease progression.
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Affiliation(s)
- William E Sweeney
- Department of Pediatrics, Medical College of Wisconsin, Children's Research Institute, Children's Hospital Health System of Wisconsin, Milwaukee, WI, USA
| | - Ellis D Avner
- Department of Pediatrics, Medical College of Wisconsin, Children's Research Institute, Children's Hospital Health System of Wisconsin, Milwaukee, WI, USA
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18
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Vaiserman AM, Lushchak OV, Koliada AK. Anti-aging pharmacology: Promises and pitfalls. Ageing Res Rev 2016; 31:9-35. [PMID: 27524412 DOI: 10.1016/j.arr.2016.08.004] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 08/06/2016] [Accepted: 08/09/2016] [Indexed: 12/12/2022]
Abstract
Life expectancy has grown dramatically in modern times. This increase, however, is not accompanied by the same increase in healthspan. Efforts to extend healthspan through pharmacological agents targeting aging-related pathological changes are now in the spotlight of geroscience, the main idea of which is that delaying of aging is far more effective than preventing the particular chronic disorders. Currently, anti-aging pharmacology is a rapidly developing discipline. It is a preventive field of health care, as opposed to conventional medicine which focuses on treating symptoms rather than root causes of illness. A number of pharmacological agents targeting basic aging pathways (i.e., calorie restriction mimetics, autophagy inducers, senolytics etc.) are now under investigation. This review summarizes the literature related to advances, perspectives and challenges in the field of anti-aging pharmacology.
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Affiliation(s)
| | - Oleh V Lushchak
- Vasyl Stefanyk Precarpathian National University, Ivano-Frankivsk, Ukraine
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Ta MHT, Schwensen KG, Foster S, Korgaonkar M, Ozimek-Kulik JE, Phillips JK, Peduto A, Rangan GK. Effects of TORC1 Inhibition during the Early and Established Phases of Polycystic Kidney Disease. PLoS One 2016; 11:e0164193. [PMID: 27723777 PMCID: PMC5056751 DOI: 10.1371/journal.pone.0164193] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 09/21/2016] [Indexed: 01/01/2023] Open
Abstract
The disease-modifying effects of target of rapamycin complex 1 (TORC1) inhibitors during different stages of polycystic kidney disease (PKD) are not well defined. In this study, male Lewis Polycystic Kidney Disease (LPK) rats (a genetic ortholog of human NPHP9, phenotypically characterised by diffuse distal nephron cystic growth) and Lewis controls received either vehicle (V) or sirolimus (S, 0.2 mg/kg by intraperitoneal injection 5 days per week) during the early (postnatal weeks 3 to 10) or late stages of disease (weeks 10 to 20). In early-stage disease, sirolimus reduced kidney enlargement (by 63%), slowed the rate of increase in total kidney volume (TKV) in serial MRI by 78.2% (LPK+V: 132.3±59.7 vs. LPK+S: 28.8±12.0% per week) but only partly reduced the percentage renal cyst area (by 19%) and did not affect the decline in endogenous creatinine clearance (CrCl) in LPK rats. In late-stage disease, sirolimus reduced kidney enlargement (by 22%) and the rate of increase in TKV by 71.8% (LPK+V: 13.1±6.6 vs. LPK+S: 3.7±3.7% per week) but the percentage renal cyst area was unaltered, and the CrCl only marginally better. Sirolimus reduced renal TORC1 activation but not TORC2, NF-κB DNA binding activity, CCL2 or TNFα expression, and abnormalities in cilia ultrastructure, hypertension and cardiac disease were also not improved. Thus, the relative treatment efficacy of TORC1 inhibition on kidney enlargement was consistent at all disease stages, but the absolute effect was determined by the timing of drug initiation. Furthermore, cystic microarchitecture, renal function and cardiac disease remain abnormal with TORC1 inhibition, indicating that additional approaches to normalise cellular dedifferentiation, inflammation and hypertension are required to completely arrest the progression of PKDs.
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Affiliation(s)
- Michelle H. T. Ta
- Michael Stern Translational Laboratory for Polycystic Kidney Disease, Centre for Transplant and Renal Research, Westmead Institute for Medical Research, University of Sydney, Sydney, Australia
| | - Kristina G. Schwensen
- Michael Stern Translational Laboratory for Polycystic Kidney Disease, Centre for Transplant and Renal Research, Westmead Institute for Medical Research, University of Sydney, Sydney, Australia
| | - Sheryl Foster
- Department of Radiology, University of Sydney at Westmead Hospital, Sydney, Australia
- Faculty of Health Sciences, University of Sydney, Sydney, Australia
| | - Mayuresh Korgaonkar
- Brain Dynamics Centre, Westmead Institute for Medical Research, University of Sydney, Sydney, Australia
| | - Justyna E. Ozimek-Kulik
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Jacqueline K. Phillips
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Anthony Peduto
- Department of Radiology, University of Sydney at Westmead Hospital, Sydney, Australia
| | - Gopala K. Rangan
- Michael Stern Translational Laboratory for Polycystic Kidney Disease, Centre for Transplant and Renal Research, Westmead Institute for Medical Research, University of Sydney, Sydney, Australia
- Department of Renal Medicine, Westmead Hospital, Western Sydney Local Heath District, Westmead, Sydney, Australia
- * E-mail:
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Rogers KA, Moreno SE, Smith LA, Husson H, Bukanov NO, Ledbetter SR, Budman Y, Lu Y, Wang B, Ibraghimov-Beskrovnaya O, Natoli TA. Differences in the timing and magnitude of Pkd1 gene deletion determine the severity of polycystic kidney disease in an orthologous mouse model of ADPKD. Physiol Rep 2016; 4:4/12/e12846. [PMID: 27356569 PMCID: PMC4926022 DOI: 10.14814/phy2.12846] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 06/07/2016] [Indexed: 12/24/2022] Open
Abstract
Development of a disease‐modifying therapy to treat autosomal dominant polycystic kidney disease (ADPKD) requires well‐characterized preclinical models that accurately reflect the pathology and biochemical changes associated with the disease. Using a Pkd1 conditional knockout mouse, we demonstrate that subtly altering the timing and extent of Pkd1 deletion can have a significant impact on the origin and severity of kidney cyst formation. Pkd1 deletion on postnatal day 1 or 2 results in cysts arising from both the cortical and medullary regions, whereas deletion on postnatal days 3–8 results in primarily medullary cyst formation. Altering the extent of Pkd1 deletion by modulating the tamoxifen dose produces dose‐dependent changes in the severity, but not origin, of cystogenesis. Limited Pkd1 deletion produces progressive kidney cystogenesis, accompanied by interstitial fibrosis and loss of kidney function. Cyst growth occurs in two phases: an early, rapid growth phase, followed by a later, slow growth period. Analysis of biochemical pathway changes in cystic kidneys reveals dysregulation of the cell cycle, increased proliferation and apoptosis, activation of Mek‐Erk, Akt‐mTOR, and Wnt‐β‐catenin signaling pathways, and altered glycosphingolipid metabolism that resemble the biochemical changes occurring in human ADPKD kidneys. These pathways are normally active in neonatal mouse kidneys until repressed around 3 weeks of age; however, they remain active following Pkd1 deletion. Together, this work describes the key parameters to accurately model the pathological and biochemical changes associated with ADPKD in a conditional mouse model.
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Affiliation(s)
- Kelly A Rogers
- Department of Rare Renal Disease Research, Sanofi-Genzyme R&D Center, Framingham, Massachusetts
| | - Sarah E Moreno
- Department of Rare Renal Disease Research, Sanofi-Genzyme R&D Center, Framingham, Massachusetts
| | - Laurie A Smith
- Department of Rare Renal Disease Research, Sanofi-Genzyme R&D Center, Framingham, Massachusetts
| | - Hervé Husson
- Department of Rare Renal Disease Research, Sanofi-Genzyme R&D Center, Framingham, Massachusetts
| | - Nikolay O Bukanov
- Department of Rare Renal Disease Research, Sanofi-Genzyme R&D Center, Framingham, Massachusetts
| | - Steven R Ledbetter
- Department of Rare Renal Disease Research, Sanofi-Genzyme R&D Center, Framingham, Massachusetts
| | - Yeva Budman
- Department of Analytical Research and Development, Sanofi Corporation, Waltham, Massachusetts
| | - Yuefeng Lu
- Department of Biostatistics and Programming, Sanofi-Genzyme R&D Center, Framingham, Massachusetts
| | - Bing Wang
- Department of Analytical Research and Development, Sanofi Corporation, Waltham, Massachusetts
| | | | - Thomas A Natoli
- Department of Rare Renal Disease Research, Sanofi-Genzyme R&D Center, Framingham, Massachusetts
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Ruggenenti P, Gentile G, Perico N, Perna A, Barcella L, Trillini M, Cortinovis M, Ferrer Siles CP, Reyes Loaeza JA, Aparicio MC, Fasolini G, Gaspari F, Martinetti D, Carrara F, Rubis N, Prandini S, Caroli A, Sharma K, Antiga L, Remuzzi A, Remuzzi G. Effect of Sirolimus on Disease Progression in Patients with Autosomal Dominant Polycystic Kidney Disease and CKD Stages 3b-4. Clin J Am Soc Nephrol 2016; 11:785-794. [PMID: 26912555 PMCID: PMC4858487 DOI: 10.2215/cjn.09900915] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 01/26/2016] [Indexed: 01/13/2023]
Abstract
BACKGROUND AND OBJECTIVES The effect of mammalian target of rapamycin (mTOR) inhibitors has never been tested in patients with autosomal dominant polycystic kidney disease (ADPKD) and severe renal insufficiency. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS In this academic, prospective, randomized, open label, blinded end point, parallel group trial (ClinicalTrials.gov no. NCT01223755), 41 adults with ADPKD, CKD stage 3b or 4, and proteinuria ≤0.5 g/24 h were randomized between September of 2010 and March of 2012 to sirolimus (3 mg/d; serum target levels of 5-10 ng/ml) added on to conventional therapy (n=21) or conventional treatment alone (n=20). Primary outcome was GFR (iohexol plasma clearance) change at 1 and 3 years versus baseline. RESULTS At the 1-year preplanned interim analysis, GFR fell from 26.7±5.8 to 21.3±6.3 ml/min per 1.73 m(2) (P<0.001) and from 29.6±5.6 to 24.9±6.2 ml/min per 1.73 m(2) (P<0.001) in the sirolimus and conventional treatment groups, respectively. Albuminuria (73.8±81.8 versus 154.9±152.9 μg/min; P=0.02) and proteinuria (0.3±0.2 versus 06±0.4 g/24 h; P<0.01) increased with sirolimus. Seven patients on sirolimus versus one control had de novo proteinuria (P=0.04), ten versus three patients doubled proteinuria (P=0.02), 18 versus 11 patients had peripheral edema (P=0.04), and 14 versus six patients had upper respiratory tract infections (P=0.03). Three patients on sirolimus had angioedema, 14 patients had aphthous stomatitis, and seven patients had acne (P<0.01 for both versus controls). Two patients progressed to ESRD, and two patients withdrew because of worsening of proteinuria. These events were not observed in controls. Thus, the independent data and safety monitoring board recommend early trial termination for safety reasons. At 1 year, total kidney volume (assessed by contrast-enhanced computed tomography imaging) increased by 9.0% from 2857.7±1447.3 to 3094.6±1519.5 ml on sirolimus and 4.3% from 3123.4±1695.3 to 3222.6±1651.4 ml on conventional therapy (P=0.12). On follow-up, 37% and 7% of serum sirolimus levels fell below or exceeded the therapeutic range, respectively. CONCLUSIONS Finding that sirolimus was unsafe and ineffective in patients with ADPKD and renal insufficiency suggests that mTOR inhibitor therapy may be contraindicated in this context.
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Affiliation(s)
- Piero Ruggenenti
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò,” IRCCS—Istituto di Ricerche Farmacologiche “Mario Negri,” Bergamo, Italy
- Units of Nephrology and Dialysis
| | - Giorgio Gentile
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò,” IRCCS—Istituto di Ricerche Farmacologiche “Mario Negri,” Bergamo, Italy
- Units of Nephrology and Dialysis
| | - Norberto Perico
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò,” IRCCS—Istituto di Ricerche Farmacologiche “Mario Negri,” Bergamo, Italy
| | - Annalisa Perna
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò,” IRCCS—Istituto di Ricerche Farmacologiche “Mario Negri,” Bergamo, Italy
| | | | - Matias Trillini
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò,” IRCCS—Istituto di Ricerche Farmacologiche “Mario Negri,” Bergamo, Italy
| | - Monica Cortinovis
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò,” IRCCS—Istituto di Ricerche Farmacologiche “Mario Negri,” Bergamo, Italy
| | - Claudia Patricia Ferrer Siles
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò,” IRCCS—Istituto di Ricerche Farmacologiche “Mario Negri,” Bergamo, Italy
| | - Jorge Arturo Reyes Loaeza
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò,” IRCCS—Istituto di Ricerche Farmacologiche “Mario Negri,” Bergamo, Italy
| | - Maria Carolina Aparicio
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò,” IRCCS—Istituto di Ricerche Farmacologiche “Mario Negri,” Bergamo, Italy
| | - Giorgio Fasolini
- Radiology, Azienda Ospedaliera Papa Giovanni XXIII, Bergamo, Italy; and
| | - Flavio Gaspari
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò,” IRCCS—Istituto di Ricerche Farmacologiche “Mario Negri,” Bergamo, Italy
| | - Davide Martinetti
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò,” IRCCS—Istituto di Ricerche Farmacologiche “Mario Negri,” Bergamo, Italy
| | - Fabiola Carrara
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò,” IRCCS—Istituto di Ricerche Farmacologiche “Mario Negri,” Bergamo, Italy
| | - Nadia Rubis
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò,” IRCCS—Istituto di Ricerche Farmacologiche “Mario Negri,” Bergamo, Italy
| | - Silvia Prandini
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò,” IRCCS—Istituto di Ricerche Farmacologiche “Mario Negri,” Bergamo, Italy
| | - Anna Caroli
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò,” IRCCS—Istituto di Ricerche Farmacologiche “Mario Negri,” Bergamo, Italy
| | - Kanishka Sharma
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò,” IRCCS—Istituto di Ricerche Farmacologiche “Mario Negri,” Bergamo, Italy
| | - Luca Antiga
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò,” IRCCS—Istituto di Ricerche Farmacologiche “Mario Negri,” Bergamo, Italy
| | - Andrea Remuzzi
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò,” IRCCS—Istituto di Ricerche Farmacologiche “Mario Negri,” Bergamo, Italy
| | - Giuseppe Remuzzi
- Clinical Research Center for Rare Diseases “Aldo e Cele Daccò,” IRCCS—Istituto di Ricerche Farmacologiche “Mario Negri,” Bergamo, Italy
- Units of Nephrology and Dialysis
- Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
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22
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Lang F, Pearce D. Regulation of the epithelial Na+ channel by the mTORC2/SGK1 pathway. Nephrol Dial Transplant 2015; 31:200-5. [PMID: 26163195 DOI: 10.1093/ndt/gfv270] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 06/05/2015] [Indexed: 12/25/2022] Open
Abstract
The epithelial Na(+) channel (ENaC) is decisive for sodium reabsorption by the aldosterone-sensitive distal nephron (ASDN) of the kidney. ENaC is regulated by the serum- and glucocorticoid-inducible kinase 1 (SGK1), a kinase genomically upregulated by several hormones including glucocorticoids and mineralocorticoids. SGK1 is activated by the serine/threonine kinase mammalian target of rapamycin (mTOR) isoform mTORC2. SGK1 knockout (sgk1(-/-) mice) impairs renal Na(+) retention during salt depletion. The mTOR catalytic site inhibitor, PP242, but not mTORC1 inhibitor rapamycin, inhibits ENaC, decreases Na(+) flux in isolated perfused tubules and induces natriuresis in wild-type mice. PP242 does not lead to further impairment of Na(+) reabsorption in sgk1(-/-) mice. The mTORC2/SGK1 sensitive renal Na(+) retention leads to extracellular volume expansion with increase of blood pressure. A SGK1 gene variant (prevalence ∼ 3-5% in Caucasians, ∼ 10% in Africans) predisposes to hypertension, stroke, obesity and type 2 diabetes. Future studies will be required to define the role of mTORC2 in the regulation of further SGK1 sensitive transport proteins, such as further ion channels, carriers and the Na(+)/K(+)-ATPase. Moreover, studies are required disclosing the impact of mTORC2 on SGK1 sensitive disorders, such as hypertension, obesity, diabetes, thrombosis, stroke, inflammation, autoimmune disease, fibrosis and tumour growth.
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Affiliation(s)
- Florian Lang
- Department of Physiology, University of Tübingen, Tübingen, Germany
| | - David Pearce
- Division of Nephrology, Department of Medicine, University of California at San Francisco, San Francisco, CA, USA
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LaRiviere WB, Irazabal MV, Torres VE. Novel therapeutic approaches to autosomal dominant polycystic kidney disease. Transl Res 2015; 165:488-98. [PMID: 25438190 PMCID: PMC4363282 DOI: 10.1016/j.trsl.2014.11.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 10/17/2014] [Accepted: 11/06/2014] [Indexed: 01/14/2023]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is an inherited disorder characterized by the progressive growth of renal cysts that, over time, destroy the architecture of the renal parenchyma and typically lead to kidney failure by the sixth decade of life. ADPKD is common and represents a leading cause of renal failure worldwide. Currently, there are no Food and Drug Administration-approved treatments for the disease, and the existing standard of care is primarily supportive in nature. However, significant advances in the understanding of the molecular biology of the disease have inspired investigation into potential new therapies. Several drugs designed to slow or arrest the progression of ADPKD have shown promise in preclinical models and clinical trials, including vasopressin receptor antagonists and somatostatin analogs. This article examines the literature underlying the rationale for molecular therapies for ADPKD and reviews the existing clinical evidence for their indication for human patients with the disease.
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Affiliation(s)
- Wells B LaRiviere
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minn
| | - Maria V Irazabal
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minn
| | - Vicente E Torres
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minn.
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Xu JX, Lu TS, Li S, Wu Y, Ding L, Denker BM, Bonventre JV, Kong T. Polycystin-1 and Gα12 regulate the cleavage of E-cadherin in kidney epithelial cells. Physiol Genomics 2014; 47:24-32. [PMID: 25492927 DOI: 10.1152/physiolgenomics.00090.2014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Interaction of polycystin-1 (PC1) and Gα12 is important for development of kidney cysts in autosomal dominant polycystic kidney disease (ADPKD). The integrity of cell polarity and cell-cell adhesions (mainly E-cadherin-mediated adherens junction) is altered in the renal epithelial cells of ADPKD. However, the key signaling pathway for this alteration is not fully understood. Madin-Darby canine kidney (MDCK) cells maintain the normal integrity of epithelial cell polarity and adherens junctions. Here, we found that deletion of Pkd1 increased activation of Gα12, which then promoted the cystogenesis of MDCK cells. The morphology of these cells was altered after the activation of Gα12. By using liquid chromatography-mass spectrometry, we found several proteins that could be related this change in the extracellular milieu. E-cadherin was one of the most abundant peptides after active Gα12 was induced. Gα12 activation or Pkd1 deletion increased the shedding of E-cadherin, which was mediated via increased ADAM10 activity. The increased shedding of E-cadherin was blocked by knockdown of ADAM10 or specific ADAM10 inhibitor GI254023X. Pkd1 deletion or Gα12 activation also changed the distribution of E-cadherin in kidney epithelial cells and caused β-catenin to shift from cell membrane to nucleus. Finally, ADAM10 inhibitor, GI254023X, blocked the cystogenesis induced by PC1 knockdown or Gα12 activation in renal epithelial cells. Our results demonstrate that the E-cadherin/β-catenin signaling pathway is regulated by PC1 and Gα12 via ADAM10. Specific inhibition of this pathway, especially ADAM10 activity, could be a novel therapeutic regimen for ADPKD.
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Affiliation(s)
- Jen X Xu
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts
| | - Tzong-Shi Lu
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts
| | - Suyan Li
- Division of Basic Neuroscience, McLean Hospital, Belmont, Massachusetts
| | - Yong Wu
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts
| | - Lai Ding
- Harvard NeuroDiscovery Center, Boston, Massachusetts; and
| | - Bradley M Denker
- Beth Israel Deaconess Medical Center, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts
| | - Joseph V Bonventre
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts
| | - Tianqing Kong
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts;
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Myint TM, Rangan GK, Webster AC. Treatments to slow progression of autosomal dominant polycystic kidney disease: systematic review and meta-analysis of randomized trials. Nephrology (Carlton) 2014; 19:217-26. [PMID: 24460701 DOI: 10.1111/nep.12211] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/19/2014] [Indexed: 01/13/2023]
Abstract
AIM Autosomal dominant polycystic kidney disease (ADPKD) is a monogenetic disorder that leads to kidney failure. Our aim was to undertake a meta-analysis of randomized trials of interventions that have been hypothesized to reduce the progression of total kidney volume (TKV) and renal function in ADPKD. METHODS Relevant trials were identified, and outcomes were: change in TKV, total cyst volume (TCV), renal function and adverse events. Meta-analysis used random effects, with results expressed as mean difference and risk ratio both with 95% confidence intervals (CI). RESULTS Eleven trials (2262 patients) were included. Compared with placebo, Target of Rapamycin complex 1 (TORC1) inhibitors (5 trials, n = 619), showed no significant change in TKV (P = 0.21), TCV (P = 0.06) or eGFR (P = 0.22). Somatostatin analogues (3 trials, n = 157) reduced TKV by 9% (95% CI -10.33 to -7.58%) but did not alter eGFR. The vasopressin receptor antagonist (n = 1455) attenuated TKV increase to 3%/year (95% CI -3.48 to -2.52) and slowed kidney function decline over a 3-year period. A single trial (n = 41) of eicosapentaenoic acid did not alter the progression of either TKV (P = 0.9) or renal dysfunction (P = 0.78). Adverse events were significant for interventions in all trials compared with placebo. CONCLUSION These data suggest that somatostatin analogues and vasopressin receptor antagonists attenuate TKV increase. The neutral effects of TORC1 inhibitors on TKV could be true, or due to heterogeneity in study population, drug efficacy and follow-up duration. In the future, further well-designed and powered trials of longer duration using new biomarkers or therapeutic agents with better tolerance are required.
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Affiliation(s)
- Thida M Myint
- Department of Renal Medicine and Transplantation, Westmead Hospital, Western Sydney Local Health District, Sydney, New South Wales, Australia
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26
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Ravichandran K, Zafar I, Ozkok A, Edelstein CL. An mTOR kinase inhibitor slows disease progression in a rat model of polycystic kidney disease. Nephrol Dial Transplant 2014; 30:45-53. [PMID: 25239638 DOI: 10.1093/ndt/gfu296] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The mTOR pathway, which consists of mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2), is activated in polycystic kidney disease (PKD) kidneys. Sirolimus and everolimus indirectly bind and inhibit mTORC1. A novel group of drugs, the mTOR kinase inhibitors, directly bind to mTOR kinase, thus inhibiting both mTORC1 and 2. The aim of the study was to determine the therapeutic effect of an mTOR kinase inhibitor, PP242, in the Han:SPRD rat (Cy/+) model of PKD. METHODS Male rats were treated with PP242 5 mg/kg/day IP or vehicle for 5 weeks. RESULTS PP242 significantly reduced the kidney enlargement, the cyst density and the blood urea nitrogen in Cy/+ rats. On immunoblot of kidneys, PP242 resulted in a decrease in pS6, a marker of mTORC1 signaling and pAkt(Ser473), a marker of mTORC2 signaling. mTORC plays an important role in regulating cytokine production. There was an increase in IL-1, IL-6, CXCL1 and TNF-α in Cy/+ rat kidneys that was unaffected by PP242. Apoptosis or proliferation is known to play a causal role in cyst growth. PP242 had no effect on caspase-3 activity, TUNEL positive or active caspase-3-positive tubular cells in Cy/+ kidneys. PP242 reduced the number of proliferating cells per cyst and per non-cystic tubule in Cy/+ rats. CONCLUSIONS In a rat model of autosomal dominant polycystic kidney disease, PP242 treatment (i) decreases proliferation in cystic and non-cystic tubules; (ii) inhibits renal enlargement and cystogenesis and (iii) significantly reduces the loss of kidney function.
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Affiliation(s)
- Kameswaran Ravichandran
- Division of Renal Diseases and Hypertension, University of Colorado at Denver, Aurora, CO, USA
| | - Iram Zafar
- Division of Renal Diseases and Hypertension, University of Colorado at Denver, Aurora, CO, USA
| | - Abdullah Ozkok
- Division of Renal Diseases and Hypertension, University of Colorado at Denver, Aurora, CO, USA
| | - Charles L Edelstein
- Division of Renal Diseases and Hypertension, University of Colorado at Denver, Aurora, CO, USA
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Gattone VH, Bacallao RL. Dichloroacetate treatment accelerates the development of pathology in rodent autosomal recessive polycystic kidney disease. Am J Physiol Renal Physiol 2014; 307:F1144-8. [PMID: 25234313 DOI: 10.1152/ajprenal.00009.2014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Dichloroacetate (DCA) is a toxicant by-product from the chlorination disinfection process for municipal water. The levels would not affect people with normal renal and liver function. However, people with impaired renal or liver function may have an increased susceptibility to DCA toxicity as those are the organs affected by DCA. People (and rodents) with polycystic kidney disease (PKD) are polyuric, drink more fluids, and have both renal and liver pathology. In PKD, renal tubules and biliary epithelial cells proliferate to form cysts, which can eventually cause renal and/or liver dysfunction. Therefore, PKD may be a predisposing condition with an increased sensitivity to DCA toxicity. PCK rats are an orthologous model of human autosomal recessive PKD and were treated with 75 mg/l DCA in their drinking water. Male and female PCK and male Sprague-Dawley rats were treated from 4 to 8 wk of age, after which the severity of the renal and liver pathology induced by DCA were assessed. Only male PCK rats were adversely affected by DCA treatment, with an increase in the severity of renal cystic disease evinced by an increase in cystic enlargement and proteinuria. In conclusion, the chlorination byproduct DCA may adversely affect those with a preexisting renal disease, especially those who are polydipsic, like those with PKD.
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Affiliation(s)
- Vincent H Gattone
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana; Department of Medicine-Nephrology, Indiana University School of Medicine, Indianapolis, Indiana; and
| | - Robert L Bacallao
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, Indiana; Department of Medicine-Nephrology, Indiana University School of Medicine, Indianapolis, Indiana; and Richard Roudebush Veterans Affairs Medical Center, Indianapolis, Indiana
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Ravichandran K, Zafar I, He Z, Doctor RB, Moldovan R, Mullick AE, Edelstein CL. An mTOR anti-sense oligonucleotide decreases polycystic kidney disease in mice with a targeted mutation in Pkd2. Hum Mol Genet 2014; 23:4919-31. [PMID: 24847003 DOI: 10.1093/hmg/ddu208] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is the most common life-threatening hereditary disease in the USA. In human ADPKD studies, sirolimus, a mammalian target of rapamycin complex 1 (mTORC1) inhibitor, had little therapeutic effect. While sirolimus robustly inhibits mTORC1, it has a minimal effect on mTOR complex 2 (mTORC2). Polycystic kidneys of Pkd2WS25/- mice, an orthologous model of human ADPKD caused by a mutation in the Pkd2 gene, had an early increase in pS6 (marker of mTORC1) and pAktSer(473) (marker of mTORC2). To investigate the effect of combined mTORC1 and 2 inhibition, Pkd2WS25/- mice were treated with an mTOR anti-sense oligonucleotide (ASO) that blocks mTOR expression thus inhibiting both mTORC1 and 2. The mTOR ASO resulted in a significant decrease in mTOR protein, pS6 and pAktSer(473). Pkd2WS25/- mice treated with the ASO had a normalization of kidney weights and kidney function and a marked decrease in cyst volume. The mTOR ASO resulted in a significant decrease in proliferation and apoptosis of tubular epithelial cells. To demonstrate the role of mTORC2 on cyst growth, Rictor, the functional component of mTORC2, was silenced in Madin-Darby canine kidney cell cysts grown in 3D cultures. Silencing Rictor significantly decreased cyst volume and expression of pAktSer(473). The decreased cyst size in the Rictor silenced cells was reversed by introduction of a constitutively active Akt1. In vitro, combined mTORC1 and 2 inhibition reduced cyst growth more than inhibition of mTORC1 or 2 alone. In conclusion, combined mTORC1 and 2 inhibition has therapeutic potential in ADPKD.
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Affiliation(s)
| | - Iram Zafar
- Division of Renal Diseases and Hypertension
| | - Zhibin He
- Division of Renal Diseases and Hypertension
| | | | - Radu Moldovan
- Advanced Light Microscopy Core Facility, University of Colorado at Denver, Aurora, CO, USA
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Braun WE, Schold JD, Stephany BR, Spirko RA, Herts BR. Low-dose rapamycin (sirolimus) effects in autosomal dominant polycystic kidney disease: an open-label randomized controlled pilot study. Clin J Am Soc Nephrol 2014; 9:881-8. [PMID: 24721888 PMCID: PMC4011437 DOI: 10.2215/cjn.02650313] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 01/04/2014] [Indexed: 01/13/2023]
Abstract
BACKGROUND AND OBJECTIVES The two largest studies of mammalian target of rapamycin inhibitor treatment of autosomal dominant polycystic kidney disease (ADPKD) demonstrated no clear benefit on the primary endpoint of total kidney volume (TKV) or on eGFR. The present study evaluated two levels of rapamycin on the 12-month change in (125)I-iothalamate GFR (iGFR) as the primary endpoint and TKV secondarily. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS In a 12-month open-label pilot study, 30 adult patients with ADPKD were randomly assigned to low-dose (LD) rapamycin (rapamycin trough blood level, 2-5 ng/ml) (LD group, n=10), standard-dose (STD) rapamycin trough level (>5-8 ng/ml) (STD group, n=10), or standard care (SC group, n=10). They were evaluated with iGFR and noncontrast computed tomography. RESULTS Change in iGFR at 12 months was significantly higher in the LD group (7.7±12.5 ml/min per 1.73 m(2); n=9) than in the SC group (-11.2 ± 9.1 ml/min per 1.73 m(2); n=9) (LD versus SC: P<0.01). Change in iGFR at 12 months in the STD group (1.6 ± 12.1 ml/min per 1.73 m(2); n=8) was not significantly greater than that in the SC group (P=0.07), but it was in the combined treatment groups (LD+STD versus SC: P<0.01). Neither eGFR calculated by the CKD-Epidemiology Collaboration equation nor TKV (secondary endpoint) changed significantly from baseline to 12 months in any of the groups. On the basis of results of the mixed model, during the study, patients in the LD group had significantly lower trough blood levels of rapamycin (mean range ± SD, 2.40 ± 0.64 to 2.90 ± 1.20 ng/ml) compared with those in the STD group (3.93 ± 2.27 to 5.77 ± 1.06 ng/ml) (P<0.01). CONCLUSION Patients with ADPKD receiving LD rapamycin demonstrated a significant increase in iGFR compared with those receiving standard care, without a significant effect on TKV after 12 months.
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Affiliation(s)
- William E Braun
- Glickman Urological and Kidney Institute,, †Quantitative Health Sciences, and, ‡Imaging Institute, Cleveland Clinic, Cleveland, Ohio
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Abstract
INTRODUCTION Autosomal-dominant polycystic kidney disease (ADPKD) represents a therapeutic challenge as effective treatment to retard the growth of cysts in the kidneys and the liver has not been available despite decades of intense basic and clinical research. AREAS COVERED Several clinical trials have been performed in recent years to study the effect of diverse drugs on the growth of renal and hepatic cysts, and on functional deterioration of the glomerular filtration rate. The drug classes that have been tested in randomized clinical trials include the mammalian target of rapamycin (mTOR) inhibitors, sirolimus and everolimus, the somatostatin analogues (octreotide, lanreotide, pasireotide), and most recently, the vasopressin V2 receptor antagonist, tolvaptan. The results with the mTOR inhibitors were disappointing, but more encouraging with the somatostatin analogues and with tolvaptan. Additional drugs are being tested, which include among others, the SRC-ABL tyrosine kinase inhibitor, bosutinib, and the traditional Chinese herbal medication, triptolide. Additional therapeutic strategies to retard cyst growth aim at blood pressure control via inhibition of the renin-angiotensin system and the sympathetic nervous system. EXPERT OPINION Given the accumulated knowledge, it is currently uncertain whether drugs will become available in the near future to significantly change the course of the relentlessly progressing polycystic kidney disease.
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Affiliation(s)
- Rudolf P Wüthrich
- University Hospital, Division of Nephrology , Rämistrasse 100, 8091 Zürich , Switzerland +41 44 255 33 84 ; +41 44 255 45 93 ;
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Wang Y, Yu Q, He X, Romigh T, Altemus J, Eng C. Activation of AR sensitizes breast carcinomas to NVP-BEZ235's therapeutic effect mediated by PTEN and KLLN upregulation. Mol Cancer Ther 2013; 13:517-27. [PMID: 24356815 DOI: 10.1158/1535-7163.mct-13-0655] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
NVP-BEZ235 is a newly developed dual PI3K/mTOR inhibitor, being tested in multiple clinical trials, including breast cancer. NVP-BEZ235 selectively induces cell growth inhibition in a subset, but not all, breast cancer cell lines. However, it remains a challenge to distinguish between sensitive and resistant tumors, particularly in the pretreatment setting. Here, we used ten breast cancer cell lines to compare NVP-BEZ235 sensitivity and in the context of androgen receptor (AR) activation during NVP-BEZ235 treatment. We also used female SCID mice bearing breast tumor xenografts to investigate the beneficial effect of dihydrotestosterone/NVP-BEZ235 combination treatment compared with each alone. We found that AR-positive breast cancer cell lines are much more sensitive to NVP-BEZ235 compared with AR-negative cells, regardless of PTEN or PI3KCA status. Reintroducing AR expression in NVP-BEZ235 nonresponsive AR-negative cells restored the response. DHT/NVP-BEZ235 combination not only resulted in a more significant growth inhibition than either drug alone, but also achieved tumor regression and complete responses for AR(+)/ER(+) tumors. This beneficial effect was mediated by dihydrotestosterone (DHT)-induced PTEN and KLLN expression. Furthermore, DHT could also reverse NVP-BEZ235-induced side effects such as skin rash and weight loss. Our data suggest that AR expression may be an independent predictive biomarker for response to NVP-BEZ235. AR induction could add benefit during NVP-BEZ235 treatment in patients, especially with AR(+)/ER(+) breast carcinomas.
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Affiliation(s)
- Yu Wang
- Corresponding Author: Charis Eng, Cleveland Clinic, 9500 Euclid Avenue, NE-50, Cleveland, OH 44195.
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Abstract
Polycystic diseases affect approximately 1/1000 and are important causes of kidney failure. No therapies presently are in clinical practice that can prevent disease progression. Multiple mouse models have been produced for the genetic forms of the disease that most commonly affect humans. In this report, we review recent progress in the field and describe some of the outstanding challenges.
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Affiliation(s)
- Luis Fernando Menezes
- Kidney Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Building 10 Room 8D46, 10 Center Drive, Bethesda, MD 20892
| | - Gregory George Germino
- Kidney Disease Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Building 10 Room 8D46, 10 Center Drive, Bethesda, MD 20892
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Mekahli D, Decuypere JP, Sammels E, Welkenhuyzen K, Schoeber J, Audrezet MP, Corvelyn A, Dechênes G, Ong ACM, Wilmer MJ, van den Heuvel L, Bultynck G, Parys JB, Missiaen L, Levtchenko E, De Smedt H. Polycystin-1 but not polycystin-2 deficiency causes upregulation of the mTOR pathway and can be synergistically targeted with rapamycin and metformin. Pflugers Arch 2013; 466:1591-604. [PMID: 24193408 DOI: 10.1007/s00424-013-1394-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 09/30/2013] [Accepted: 10/21/2013] [Indexed: 12/22/2022]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is caused by loss-of-function mutations in either PKD1 or PKD2 genes, which encode polycystin-1 (TRPP1) and polycystin-2 (TRPP2), respectively. Increased activity of the mammalian target of rapamycin (mTOR) pathway has been shown in PKD1 mutants but is less documented for PKD2 mutants. Clinical trials using mTOR inhibitors were disappointing, while the AMP-activated kinase (AMPK) activator, metformin is not yet tested in patients. Here, we studied the mTOR activity and its upstream pathways in several human and mouse renal cell models with either siRNA or stable knockdown and with overexpression of TRPP2. Our data reveal for the first time differences between TRPP1 and TRPP2 deficiency. In contrast to TRPP1 deficiency, TRPP2-deficient cells did neither display excessive activation of the mTOR-kinase complex nor inhibition of AMPK activity, while ERK1/2 and Akt activity were similarly affected among TRPP1- and TRPP2-deficient cells. Furthermore, cell proliferation was more pronounced in TRPP1 than in TRPP2-deficient cells. Interestingly, combining low concentrations of rapamycin and metformin was more effective for inhibiting mTOR complex 1 activity in TRPP1-deficient cells than either drug alone. Our results demonstrate a synergistic effect of a combination of low concentrations of drugs suppressing the increased mTOR activity in TRPP1-deficient cells. This novel insight can be exploited in future clinical trials to optimize the efficiency and avoiding side effects of drugs in the treatment of ADPKD patients with PKD1 mutations. Furthermore, as TRPP2 deficiency by itself did not affect mTOR signaling, this may underlie the differences in phenotype, and genetic testing has to be considered for selecting patients for the ongoing trials.
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Affiliation(s)
- Djalila Mekahli
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, KU Leuven, Campus Gasthuisberg O&N I, Leuven, Belgium,
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Fouraschen SMG, de Ruiter PE, Kwekkeboom J, de Bruin RWF, Kazemier G, Metselaar HJ, Tilanus HW, van der Laan LJW, de Jonge J. mTOR signaling in liver regeneration: Rapamycin combined with growth factor treatment. World J Transplant 2013; 3:36-47. [PMID: 24255881 PMCID: PMC3832859 DOI: 10.5500/wjt.v3.i3.36] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 05/28/2013] [Accepted: 06/19/2013] [Indexed: 02/05/2023] Open
Abstract
AIM: To investigate the effects of mammalian target of rapamycin (mTOR) inhibition on liver regeneration and autophagy in a surgical resection model.
METHODS: C57BL/6 mice were subjected to a 70% partial hepatectomy (PH) and treated intraperitoneally every 24 h with a combination of the mTOR inhibitor rapamycin (2.5 mg/kg per day) and the steroid dexamethasone (2.0 mg/kg per day) in phosphate buffered saline (PBS) or with PBS alone as vehicle control. In the immunosuppressant group, part of the group was treated subcutaneously 4 h prior to and 24 h after PH with a combination of human recombinant interleukin 6 (IL-6; 500 μg/kg per day) and hepatocyte growth factor (HGF; 100 μg/kg per day) in PBS. Animals were sacrificed 2, 3 or 5 d after PH and liver tissue and blood were collected for further analysis. Immunohistochemical staining for 5-Bromo-2’-deoxyuridine (BrdU) was used to quantify hepatocyte proliferation. Western blotting was used to detect hepatic microtubule-associated protein 1 light chain 3 (LC3)-II protein expression as a marker for autophagy. Hepatic gene expression levels of proliferation-, inflammation- and angiogenesis-related genes were examined by real-time reverse transcription-polymerase chain reaction and serum bilirubin and transaminase levels were analyzed at the clinical chemical core facility of the Erasmus MC-University Medical Center.
RESULTS: mTOR inhibition significantly suppressed regeneration, shown by decreased hepatocyte proliferation (2% vs 12% BrdU positive hepatocyte nuclei at day 2, P < 0.01; 0.8% vs 1.4% at day 5, P = 0.02) and liver weight reconstitution (63% vs 76% of initial total liver weight at day 3, P = 0.04), and furthermore increased serum transaminase levels (aspartate aminotransferase 641 U/L vs 185 U/L at day 2, P = 0.02). Expression of the autophagy marker LC3-II, which was reduced during normal liver regeneration, increased after mTOR inhibition (46% increase at day 2, P = 0.04). Hepatic gene expression showed an increased inflammation-related response [tumor necrosis factor (TNF)-α 3.2-fold upregulation at day 2, P = 0.03; IL-1Ra 6.0-fold upregulation at day 2 and 42.3-fold upregulation at day 5, P < 0.01] and a reduced expression of cell cycle progression and angiogenesis-related factors (HGF 40% reduction at day 2; vascular endothelial growth factor receptor 2 50% reduction at days 2 and 5; angiopoietin 1 60% reduction at day 2, all P≤ 0.01). Treatment with the regeneration stimulating cytokine IL-6 and growth factor HGF could overcome the inhibitory effect on liver weight (75% of initial total liver weight at day 3, P = 0.02 vs immunosuppression alone and P = 0.90 vs controls) and partially reversed gene expression changes caused by rapamycin (TNF-α and IL-1Ra levels at day 2 were restored to control levels). However, no significant changes in hepatocyte proliferation, serum injury markers or autophagy were found.
CONCLUSION: mTOR inhibition severely impairs liver regeneration and increases autophagy after PH. These effects are partly reversed by stimulation of the IL-6 and HGF pathways.
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Looking at the (w)hole: magnet resonance imaging in polycystic kidney disease. Pediatr Nephrol 2013; 28:1771-83. [PMID: 23239392 DOI: 10.1007/s00467-012-2370-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 10/23/2012] [Accepted: 10/24/2012] [Indexed: 12/29/2022]
Abstract
Inherited cystic kidney diseases, including autosomal dominant polycystic kidney disease (ADPKD) and autosomal recessive polycystic kidney disease (ARPKD), are the most common monogenetic causes of end-stage renal disease (ESRD) in children and adults. While ARPKD is a rare and usually severe pediatric disease, the more common ADPKD typically shows a slowly progressive course leading to ESRD in adulthood. At the present time there is no established disease-modifying treatment for either ARPKD or ADPKD. Various therapeutic approaches are currently under investigation, such as V2 receptor antagonists, somatostatins, and mTOR inhibitors. Renal function remains stable for decades in ADPKD, and thus clinically meaningful surrogate markers to assess therapeutic efficacy are needed. Various studies have pointed out that total kidney volume (TKV) is a potential surrogate parameter for disease severity in ADPKD. Recent trials have therefore measured TKV by magnet resonance imaging (MRI) to monitor and to predict disease progression. Here, we discuss novel insights on polycystic kidney disease (PKD), the value of MRI, and the measurement of TKV in the diagnosis and follow-up of PKD, as well as novel emerging therapeutic strategies for ADPKD.
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Xie K, Jin B, Li Y, Luo X, Zhu J, Ma D, Shi H. Modulating autophagy improves cardiac function in a rat model of early-stage dilated cardiomyopathy. Cardiology 2013; 125:60-8. [PMID: 23636065 DOI: 10.1159/000348308] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 01/16/2013] [Indexed: 01/06/2023]
Abstract
OBJECTIVES Previous studies reported that autophagy is activated in human dilated cardiomyopathy (DCM). It is still unknown whether modulating autophagy can improve cardiac function of the failing heart. METHODS We immunized rats with porcine cardiac myosin to set up a model of DCM. Rapamycin, a kind of mTOR inhibitor upregulating autophagy, was given to rats weeks after the immunization at low (1 mg/kg · day i.p.), intermediate (2 mg/kg · day i.p.) and high dose (4 mg/kg · day i.p.) for 2 weeks. RESULTS Compared to the control group (ejection fraction, EF = 81.3 ± 3.8%), the average EF decreased in both the DCM group (EF = 56.1 ± 3.3%) and the high-dose rapamycin group (EF = 55.9 ± 3.6%), but recovered in the low-/intermediate-dose rapamycin groups (EF = 64.9 ± 4.6/69.4 ± 4.4%). Phosphorylation of p70s6k and 4E-BP1 decreased and the expression of LC3BI/II increased in all rapamycin groups. Autophagic vacuoles were easily found in these groups. However, body weight was significantly reduced in the rapamycin groups. Furthermore, mortality was increased in the high-dose rapamycin group. CONCLUSIONS Rapamycin could improve cardiac function of early-stage DCM, but the effect of rapamycin turned out to be biphasic and the effective range appeared narrow.
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Affiliation(s)
- Kun Xie
- Department of Cardiology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
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Efficacy and safety of mTOR inhibitor therapy in patients with early-stage autosomal dominant polycystic kidney disease: a meta-analysis of randomized controlled trials. Am J Med Sci 2013; 344:491-7. [PMID: 22902868 DOI: 10.1097/maj.0b013e318256754f] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND The objective of this study was to conduct a meta-analysis of randomized controlled trials (RCTs) to present a profound review and an objective appraisal of the efficacy and safety of the mammalian target of rapamycin (mTOR) inhibitor therapy in patients with autosomal dominant polycystic kidney disease (ADPKD). METHODS RCTs involving the mTOR inhibitor therapy in patients with ADPKD are included. The data of studies and major outcomes include changes in patients' glomerular filtration rate (GFR), urinary protein, total kidney volume (TKV), cyst volume, parenchymal volume, and lipid profile and the frequency of adverse events. Review Manager 5.0 for meta-analysis was used in this study. RESULTS Up to January 31, 2011, 4 RCTs (with a total of 564 patients) were included. The mTOR inhibitor therapy group had smaller TKV than the control group [weighted mean difference (WMD) of TKV after treatment: -318.45, P = 0.04]. The mTOR inhibitor treatment does not necessarily slow down the aggravation of renal function in patients with ADPKD (WMD of GFR after therapy: 5.55, P < 0.01; at 6-month analyses = -0.97, P = 0.56). Side effects could occur during the mTOR inhibitor therapy, but the severities can be controlled by the appropriate use of drug. CONCLUSIONS Based on the current limited clinical trials, this study suggests that short-duration mTOR inhibitor therapy is relatively safe to slow down the increase in kidney volume in patients with early-stage ADPKD, but it has limited impact on slowing down the decrease in GFR.
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Braun M, Young J, Reiner CS, Poster D, Krauer F, Kistler AD, Kristanto P, Wang X, Liu Y, Loffing J, Andreisek G, von Eckardstein A, Senn O, Wüthrich RP, Serra AL. Low-dose oral sirolimus and the risk of menstrual-cycle disturbances and ovarian cysts: analysis of the randomized controlled SUISSE ADPKD trial. PLoS One 2012; 7:e45868. [PMID: 23071528 PMCID: PMC3468602 DOI: 10.1371/journal.pone.0045868] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Accepted: 08/22/2012] [Indexed: 01/05/2023] Open
Abstract
UNLABELLED Sirolimus has been approved for clinical use in non proliferative and proliferative disorders. It inhibits the mammalian target of rapamycin (mTOR) signaling pathway which is also known to regulate ovarian morphology and function. Preliminary observational data suggest the potential for ovarian toxicity but this issue has not been studied in randomized controlled trials. We reviewed the self-reported occurrence of menstrual cycle disturbances and the appearance of ovarian cysts post hoc in an open label randomized controlled phase II trial conducted at the University Hospital Zürich between March 2006 and March 2010. Adult females with autosomal dominant polycystic kidney disease, an inherited kidney disease not known to affect ovarian morphology and function, were treated with 1.3 to 1.5 mg sirolimus per day for a median of 19 months (N = 21) or standard care (N = 18). Sirolimus increased the risk of both oligoamenorrhea (hazard ratio [HR] 4.3, 95% confidence interval [CI] 1.1 to 29) and ovarian cysts (HR 4.4, CI 1.1 to 26); one patient was cystectomized five months after starting treatment with sirolimus. We also studied mechanisms of sirolimus-associated ovarian toxicity in rats. Sirolimus amplified signaling in rat ovarian follicles through the pro-proliferative phosphatidylinositol 3-kinase pathway. Low dose oral sirolimus increases the risk of menstrual cycle disturbances and ovarian cysts and monitoring of sirolimus-associated ovarian toxicity is warranted and might guide clinical practice with mammalian target of rapamycin inhibitors. TRIAL REGISTRATION ClinicalTrials.gov NCT00346918.
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Affiliation(s)
- Matthias Braun
- Division of Nephrology, University Hospital, Zürich, Switzerland
| | - James Young
- Biometrical Practice BIOP AG, Basel, Switzerland
| | - Cäcilia S. Reiner
- Division of Diagnostic and Interventional Radiology, University Hospital, Zürich, Switzerland
| | - Diane Poster
- Division of Nephrology, University Hospital, Zürich, Switzerland
| | - Fabienne Krauer
- Division of Nephrology, University Hospital, Zürich, Switzerland
| | | | - Paulus Kristanto
- Medication Adherence Research Centre, AARDEX Group, Visé, Belgium
| | - Xueqi Wang
- Department of Nephrology, Changzheng Hospital, Shanghai, China
| | - Yang Liu
- Center for Integrative Human Research, University of Zürich, Zürich, Switzerland
| | | | - Gustav Andreisek
- Division of Diagnostic and Interventional Radiology, University Hospital, Zürich, Switzerland
| | | | - Oliver Senn
- Institute of General Practice and Health Services Research, University Hospital, Zürich, Switzerland
| | | | - Andreas L. Serra
- Division of Nephrology, University Hospital, Zürich, Switzerland
- * E-mail:
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Kim HJ, Edelstein CL. Mammalian target of rapamycin inhibition in polycystic kidney disease: From bench to bedside. Kidney Res Clin Pract 2012; 31:132-8. [PMID: 26894018 PMCID: PMC4716095 DOI: 10.1016/j.krcp.2012.07.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 06/19/2012] [Accepted: 06/19/2012] [Indexed: 10/28/2022] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is the most common life-threatening hereditary disease in the USA resulting in chronic kidney disease and the need for dialysis and transplantation. Approximately 85% of cases of ADPKD are caused by a mutation in the Pkd1 gene that encodes polycystin-1, a large membrane receptor. The Pkd1 gene mutation results in abnormal proliferation in tubular epithelial cells, which plays a crucial role in cyst development and/or growth in PKD. Activation of the proliferative mammalian target of rapamycin (mTOR) signaling pathway has been demonstrated in polycystic kidneys from rodents and humans. mTOR inhibition with sirolimus or everolimus decreases cysts in most animal models of PKD including Pkd1 and Pkd2 gene deficient orthologous models of human disease. On the basis of animal studies, human studies were undertaken. Two large randomized clinical trials published in the New England Journal of Medicine of everolimus or sirolimus in ADPKD patients were very unimpressive and associated with a high side-effect profile. Possible reasons for the unimpressive nature of the human studies include their short duration, the high drop-out rate, suboptimal dosing, lack of randomization of "fast" and "slow progressors" and the lack of correlation between kidney size and kidney function in ADPKD. The future of mTOR inhibition in ADPKD is discussed.
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Affiliation(s)
- Hyun-Jung Kim
- Division of Renal Diseases and Hypertension, Univ. of Colorado at Denver, Aurora, Colorado, USA
- Department of Internal Medicine, School of Medicine, Gyeongsang National University, Jinju, Korea
| | - Charles L. Edelstein
- Division of Renal Diseases and Hypertension, Univ. of Colorado at Denver, Aurora, Colorado, USA
- Corresponding author. University of Colorado at Denver and the Health Sciences Center, Box C281, 12700 East, 19th Ave, Aurora, CO 80262, USA.
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Shillingford JM, Leamon CP, Vlahov IR, Weimbs T. Folate-conjugated rapamycin slows progression of polycystic kidney disease. J Am Soc Nephrol 2012; 23:1674-81. [PMID: 22859856 DOI: 10.1681/asn.2012040367] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Activation of the mammalian target of rapamycin (mTOR) signaling pathway is aberrant in autosomal-dominant polycystic kidney disease (ADPKD). The mTOR inhibitors, such as rapamycin, ameliorate PKD in rodent models, but clinical trials have not shown benefit, possibly as a result of low tissue concentrations of rapamycin at clinically tolerable doses. To overcome this limitation, we synthesized a folate-conjugated form of rapamycin (FC-rapa) that is taken up by folate receptor-mediated endocytosis and cleaved intracellularly to reconstitute the active drug. We found that renal cyst-lining cells highly express the folate receptor in ADPKD and mouse models. In vitro, FC-rapa inhibited mTOR activity in a dose- and folate receptor-dependent manner. Treatment of a PKD mouse model with FC-rapa inhibited mTOR in the target tissue, strongly attenuated proliferation and growth of renal cysts and preserved renal function. Furthermore, FC-rapa inhibited mTOR activity in the kidney but not in other organs. In summary, these results suggest that targeting the kidney using FC-rapa may overcome the significant side effects and lack of renal efficacy observed in clinical trials with mTOR inhibitors in ADPKD.
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Affiliation(s)
- Jonathan M Shillingford
- Molecular, Cellular, and Developmental Biology, University of California-Santa Barbara, CA 93106-9610, USA
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WITHDRAWN: Mammalian target of rapamycin (mTOR) inhibition in polycystic kidney disease (PKD): From bench to bedside. Kidney Res Clin Pract 2012. [DOI: 10.1016/j.krcp.2012.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Lieberthal W, Levine JS. Mammalian target of rapamycin and the kidney. II. Pathophysiology and therapeutic implications. Am J Physiol Renal Physiol 2012; 303:F180-91. [PMID: 22496407 DOI: 10.1152/ajprenal.00015.2012] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The mTOR pathway plays an important role in a number of common renal diseases, including acute kidney injury (AKI), diabetic nephropathy (DN), and polycystic kidney diseases (PKD). The activity of mTOR complex 1 (mTORC1) is necessary for renal regeneration and repair after AKI, and inhibition of mTORC1 by rapamycin has been shown to delay recovery from ischemic AKI in animal studies, and to prolong delayed graft function in humans who have received a kidney transplant. For this reason, administration of rapamycin should be delayed or discontinued in patients with AKI until full recovery of renal function has occurred. On the other hand, inappropriately high mTORC1 activity contributes to the progression of the metabolic syndrome, the development of type 2 diabetes, and the pathogenesis of DN. In addition, chronic hyperactivity of mTORC1, and possibly also mTORC2, contributes to cyst formation and enlargement in a number of forms of PKD. Inhibition of mTOR, using either rapamycin (which inhibits predominantly mTORC1) or "catalytic" inhibitors (which effectively inhibit both mTORC1 and mTORC2), provide exciting possibilities for novel forms of treatment of DN and PKD. In this second part of the review, we will examine the role of mTOR in the pathophysiology of DN and PKD, as well as the potential utility of currently available and newly developed inhibitors of mTOR to slow the progression of DN and/or PKD.
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Affiliation(s)
- Wilfred Lieberthal
- Stony Brook Univ. Medical Center, Health Sciences Center, Stony Brook, NY 11794-8166, USA.
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Kurdián M, Herrero-Fresneda I, Lloberas N, Gimenez-Bonafe P, Coria V, Grande MT, Boggia J, Malacrida L, Torras J, Arévalo MA, González-Martínez F, López-Novoa JM, Grinyó J, Noboa O. Delayed mTOR inhibition with low dose of everolimus reduces TGFβ expression, attenuates proteinuria and renal damage in the renal mass reduction model. PLoS One 2012; 7:e32516. [PMID: 22427849 PMCID: PMC3299670 DOI: 10.1371/journal.pone.0032516] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Accepted: 02/01/2012] [Indexed: 12/12/2022] Open
Abstract
Background The immunosuppressive mammalian target of rapamycin (mTOR) inhibitors are widely used in solid organ transplantation, but their effect on kidney disease progression is controversial. mTOR has emerged as one of the main pathways regulating cell growth, proliferation, differentiation, migration, and survival. The aim of this study was to analyze the effects of delayed inhibition of mTOR pathway with low dose of everolimus on progression of renal disease and TGFβ expression in the 5/6 nephrectomy model in Wistar rats. Methods This study evaluated the effects of everolimus (0.3 mg/k/day) introduced 15 days after surgical procedure on renal function, proteinuria, renal histology and mechanisms of fibrosis and proliferation. Results Everolimus treated group (EveG) showed significantly less proteinuria and albuminuria, less glomerular and tubulointerstitial damage and fibrosis, fibroblast activation cell proliferation, when compared with control group (CG), even though the EveG remained with high blood pressure. Treatment with everolimus also diminished glomerular hypertrophy. Everolimus effectively inhibited the increase of mTOR developed in 5/6 nephrectomy animals, without changes in AKT mRNA or protein abundance, but with an increase in the pAKT/AKT ratio. Associated with this inhibition, everolimus blunted the increased expression of TGFβ observed in the remnant kidney model. Conclusion Delayed mTOR inhibition with low dose of everolimus significantly prevented progressive renal damage and protected the remnant kidney. mTOR and TGFβ mRNA reduction can partially explain this anti fibrotic effect. mTOR can be a new target to attenuate the progression of chronic kidney disease even in those nephropathies of non-immunologic origin.
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Affiliation(s)
- Melania Kurdián
- Centro de Nefrología, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
- Departamento de Fisiopatología, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Inmaculada Herrero-Fresneda
- Laboratorio de Nefrología Experimental, Departamento de Medicina, Hospital Universitari de Bellvitge, Barcelona, Spain
| | - Nuria Lloberas
- Laboratorio de Nefrología Experimental, Departamento de Medicina, Hospital Universitari de Bellvitge, Barcelona, Spain
| | - Pepita Gimenez-Bonafe
- Departamento de Ciencias Fisiológicas II, Facultad de Medicina, Campus de Bellvitge, Universitat de Barcelona, Spain
| | - Virginia Coria
- Centro de Nefrología, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - María T. Grande
- Departamento de Anatomía e Histología Humanas, Facultad de Medicina, Universidad de Salamanca, Salamanca, Spain
| | - José Boggia
- Centro de Nefrología, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
- Departamento de Fisiopatología, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Leonel Malacrida
- Departamento de Fisiopatología, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Joan Torras
- Laboratorio de Nefrología Experimental, Departamento de Medicina, Hospital Universitari de Bellvitge, Barcelona, Spain
| | - Miguel A. Arévalo
- Departamento de Anatomía e Histología Humanas, Facultad de Medicina, Universidad de Salamanca, Salamanca, Spain
| | - Francisco González-Martínez
- Centro de Nefrología, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - José M. López-Novoa
- Departamento de Fisiología y Farmacología, Instituto Reina Sofía de Investigación Nefrológica, Universidad de Salamanca, Salamanca, Spain
| | - Josep Grinyó
- Laboratorio de Nefrología Experimental, Departamento de Medicina, Hospital Universitari de Bellvitge, Barcelona, Spain
| | - Oscar Noboa
- Centro de Nefrología, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
- Departamento de Fisiopatología, Hospital de Clínicas, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
- * E-mail:
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Novalic Z, van der Wal AM, Leonhard WN, Koehl G, Breuning MH, Geissler EK, de Heer E, Peters DJM. Dose-dependent effects of sirolimus on mTOR signaling and polycystic kidney disease. J Am Soc Nephrol 2012; 23:842-53. [PMID: 22343118 DOI: 10.1681/asn.2011040340] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Inhibition of the mammalian target of rapamycin (mTOR) shows beneficial effects in animal models of polycystic kidney disease (PKD); however, two clinical trials in patients with autosomal dominant PKD failed to demonstrate a short-term benefit in either the early or progressive stages of disease. The stage of disease during treatment and the dose of mTOR inhibitors may account for these differing results. Here, we studied the effects of a conventional low dose and a higher dose of sirolimus (blood levels of 3 ng/ml and 30-60 ng/ml, respectively) on mTOR activity and renal cystic disease in two Pkd1-mutant mouse models at different stages of the disease. When initiated at early but not late stages of disease, high-dose treatment strongly reduced mTOR signaling in renal tissues, inhibited cystogenesis, accelerated cyst regression, and abrogated fibrosis and the infiltration of immune cells. In contrast, low-dose treatment did not significantly reduce renal cystic disease. Levels of p-S6Rp(Ser240/244), which marks mTOR activity, varied between kidneys; severity of the renal cystic phenotype correlated with the level of mTOR activity. Taken together, these data suggest that long-term treatment with conventional doses of sirolimus is insufficient to inhibit mTOR activity in renal cystic tissue. Mechanisms to increase bioavailability or to target mTOR inhibitors more specifically to kidneys, alone or in combination with other compounds, may improve the potential for these therapies in PKD.
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Affiliation(s)
- Zlata Novalic
- Department of Human and Clinical Genetics, Leiden University Medical Center, The Netherlands
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45
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Parikh CR, Dahl NK, Chapman AB, Bost JE, Edelstein CL, Comer DM, Zeltner R, Tian X, Grantham JJ, Somlo S. Evaluation of urine biomarkers of kidney injury in polycystic kidney disease. Kidney Int 2012; 81:784-90. [PMID: 22258321 PMCID: PMC3319327 DOI: 10.1038/ki.2011.465] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Progressive disruption of renal tubular integrity in the setting of increased cellular proliferation and apoptosis is a feature of ADPKD. Here we evaluated the effect of these processes on the expression of NGAL and IL-18, markers of tubular injury, in rodent models and in the cyst fluid and urine of patients with ADPKD. Two mouse models where Pkd2 was inactivated which resulted in early or adult onset cysts, were used to evaluate NGAL levels. Further, the Han:SPRD rat model of polycystic disease was used to study IL-18 levels. In four annual serial urine samples from 107 patients with ADPKD in the Consortium for Radiologic Imaging for the Study of Polycystic Kidney Disease (CRISP) study, NGAL and IL-18 excretion rates were determined in conjunction with measures of total kidney volume and estimated GFR (eGFR) by the MDRD equation. Kidneys from affected mice and rats showed prominent expression of NGAL and IL-18/IL-18R, respectively, in epithelial cells lining kidney cysts. In human ADPKD cyst fluid, both NGAL and IL-18 were elevated. In CRISP patients, the mean percentage increase in total kidney volume was 5.4 /year and the mean decline in eGFR 2.4 mL/min/year. The trend of increased mean urine NGAL and IL-18 over three years was statistically significant; however, there was no association of tertiles of IL-18 or quartiles of NGAL and the change in total kidney volume or eGFR over this period. Thus, urinary NGAL and IL-18 excretion are mildly and stably elevated in ADPKD, but do not correlate with changes in total kidney volume or kidney function. This may be due, in part, to the lack of communication between individual cysts and the urinary collecting system in this disorder.
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Affiliation(s)
- Chirag R Parikh
- Department of Medicine (Nephrology), Yale University School of Medicine, New Haven, Connecticut 06516, USA.
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Abstract
Polycystic kidney disease (PKD) is a common genetic disorder in which extensive epithelial-lined cysts develop in the kidneys. In previous studies, abnormalities of polycystin protein and its interacting proteins, as well as primary cilia, have been suggested to play critical roles in the development of renal cysts. However, although several therapeutic targets for PKD have been suggested, no early diagnosis or effective treatments are currently available. Current developments are active for treatment of PKD including inhibitors or antagonists of PPAR-γ, TNF-α, CDK and VEGF. These drugs are potential therapeutic targets in PKD, and need to be determined about pathological functions in human PKD. It has recently been reported that the alteration of epigenetic regulation, as well as gene mutations, may affect the pathogenesis of PKD. In this review, we will discuss recent approaches to PKD therapy. It provides important information regarding potential targets for PKD.
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Affiliation(s)
- Eun Young Park
- Department of Biological Science, Sookmyung Women's University, Seoul 140-742, Korea
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Sun Y, Zhou H, Yang BX. Drug discovery for polycystic kidney disease. Acta Pharmacol Sin 2011; 32:805-16. [PMID: 21642949 PMCID: PMC4009953 DOI: 10.1038/aps.2011.29] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2011] [Accepted: 03/17/2011] [Indexed: 12/19/2022]
Abstract
In polycystic kidney disease (PKD), a most common human genetic diseases, fluid-filled cysts displace normal renal tubules and cause end-stage renal failure. PKD is a serious and costly disorder. There is no available therapy that prevents or slows down the cystogenesis and cyst expansion in PKD. Numerous efforts have been made to find drug targets and the candidate drugs to treat PKD. Recent studies have defined the mechanisms underlying PKD and new therapies directed toward them. In this review article, we summarize the pathogenesis of PKD, possible drug targets, available PKD models for screening and evaluating new drugs as well as candidate drugs that are being developed.
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Affiliation(s)
- Ying Sun
- Department of Pharmacology, School of Basic Medical Sciences, Peking University, and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing 100191, China
| | - Hong Zhou
- Department of Pharmacology, School of Basic Medical Sciences, Peking University, and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing 100191, China
| | - Bao-xue Yang
- Department of Pharmacology, School of Basic Medical Sciences, Peking University, and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing 100191, China
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Belibi F, Zafar I, Ravichandran K, Segvic AB, Jani A, Ljubanovic DG, Edelstein CL. Hypoxia-inducible factor-1α (HIF-1α) and autophagy in polycystic kidney disease (PKD). Am J Physiol Renal Physiol 2011; 300:F1235-43. [PMID: 21270095 PMCID: PMC3094047 DOI: 10.1152/ajprenal.00348.2010] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Accepted: 01/24/2011] [Indexed: 01/05/2023] Open
Abstract
Cyst expansion in polycystic kidney disease (PKD) results in localized hypoxia in the kidney that may activate hypoxia-inducible factor-1α (HIF-1α). HIF-1α and autophagy, a form of programmed cell repair, are induced by hypoxia. The purposes were to determine HIF-1α expression and autophagy in rat and mouse models of PKD. HIF-1α was detected by electrochemiluminescence. Autophagy was visualized by electron microscopy (EM). LC3 and beclin-1, markers of autophagy, were detected by immunoblotting. Eight-week-old male heterozygous (Cy/+) and 4-wk-old homozygous (Cy/Cy) Han:SPRD rats, 4-wk-old cpk mice, and 112-day-old Pkd2WS25/- mice with a mutation in the Pkd2 gene were studied. HIF-1α was significantly increased in massive Cy/Cy and cpk kidneys and not smaller Cy/+ and Pkd2WS25/- kidneys. On EM, features of autophagy were seen in wild-type (+/+), Cy/+, and cpk kidneys: autophagosomes, mitophagy, and autolysosomes. Specifically, autophagosomes were found on EM in the tubular cells lining the cysts in cpk mice. The increase in LC3-II, a marker of autophagosome production and beclin, a regulator of autophagy, in Cy/Cy and cpk kidneys, followed the same pattern of increase as HIF-1α. To determine the role of HIF-1α in cyst formation and/or growth, Cy/+ rats, Cy/Cy rats, and cpk mice were treated with the HIF-1α inhibitor 2-methoxyestradiol (2ME2). 2ME2 had no significant effect on kidney volume or cyst volume density. In summary, HIF-1α is highly expressed in the late stages of PKD and is associated with an increase in LC3-II and beclin-1. The first demonstration of autophagosomes in PKD kidneys is reported. Inhibition of HIF-1α did not have a therapeutic effect.
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Affiliation(s)
- Franck Belibi
- Division of Renal Diseases and Hypertension, University of Colorado at Denver and Health Sciences Center, Aurora, 80262, USA
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Abstract
Polycystic kidney disease is a common genetic disorder in which fluid-filled cysts displace normal renal tubules. Here we focus on autosomal dominant polycystic kidney disease, which is attributable to mutations in the PKD1 and PKD2 genes and which is characterized by perturbations of renal epithelial cell growth control, fluid transport, and morphogenesis. The mechanisms that connect the underlying genetic defects to disease pathogenesis are poorly understood, but their exploration is shedding new light on interesting cell biological processes and suggesting novel therapeutic targets.
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Affiliation(s)
- Hannah C Chapin
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520, USA
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50
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Wüthrich R, Kistler A, Serra A. Impact of Mammalian Target of Rapamycin Inhibition on Autosomal-Dominant Polycystic Kidney Disease. Transplant Proc 2010; 42:S44-6. [DOI: 10.1016/j.transproceed.2010.07.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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