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Wlaschek M, Maity P, Koroma AK, Geiger H, Singh K, Scharffetter-Kochanek K. Imbalanced redox dynamics induce fibroblast senescence leading to impaired stem cell pools and skin aging. Free Radic Biol Med 2025; 233:292-301. [PMID: 40154755 DOI: 10.1016/j.freeradbiomed.2025.03.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2024] [Revised: 03/05/2025] [Accepted: 03/17/2025] [Indexed: 04/01/2025]
Abstract
Skin function depends on a meticulously regulated dynamic interaction of distinct skin compartments such as the epidermis and dermis. Adaptive responses at the molecular and cellular level are essential for these interactions - and if dysregulated - drive skin aging and other pathologies. After defining the role of redox homeodynamics in physiology and aging pathology, we focus on the redox distress-dependent aging of dermal fibroblasts including their progenitors. We here discuss the prime role of senescent fibroblasts in the control of their own endogenous niche and stem cell niches for epidermal stem cells, hair follicle stem cells, adipocyte precursors and muscle stem cells. We here review that redox imbalance induced reduction in Insulin-like Growth Factor-1 drives skin aging by the depletion of stem cell pools. This IGF-1 reduction is mediated via the redox-sensitive transcription factor JunB and also by the redox-dependent changes in sphingolipid-metabolism, among others. In addition, we will discuss the changes in the extracellular matrix of the skin affecting cellular senescence and the skin integrity and function in aging. The aim is a deeper understanding of the two main redox-dependent hubs such as JunB-induced depletion of IGF-1, and the sphingolipid-mediated remodeling of the cell membrane with its impact on IGF-1, fibroblast heterogeneity, function, senescence and plasticity in skin aging.
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Affiliation(s)
- Meinhard Wlaschek
- Department of Dermatology and Allergic Diseases, Ulm University, Ulm, Germany; Aging Research Institute (arc), Ulm University, Ulm, Germany
| | - Pallab Maity
- Department of Dermatology and Allergic Diseases, Ulm University, Ulm, Germany; Aging Research Institute (arc), Ulm University, Ulm, Germany
| | - Albert Kallon Koroma
- Department of Dermatology and Allergic Diseases, Ulm University, Ulm, Germany; Aging Research Institute (arc), Ulm University, Ulm, Germany
| | - Hartmut Geiger
- Aging Research Institute (arc), Ulm University, Ulm, Germany; Institute for Molecular Medicine and Stem Cell Aging, Ulm University, Ulm, Germany
| | - Karmveer Singh
- Department of Dermatology and Allergic Diseases, Ulm University, Ulm, Germany; Aging Research Institute (arc), Ulm University, Ulm, Germany
| | - Karin Scharffetter-Kochanek
- Department of Dermatology and Allergic Diseases, Ulm University, Ulm, Germany; Aging Research Institute (arc), Ulm University, Ulm, Germany.
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2
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Pollack AS, Kunder CA, Brazer N, Shen Z, Varma S, West RB, Cunha GR, Baskin LS, Brooks JD, Pollack JR. Spatial transcriptomics identifies candidate stromal drivers of benign prostatic hyperplasia. JCI Insight 2024; 9:e176479. [PMID: 37971878 PMCID: PMC10906230 DOI: 10.1172/jci.insight.176479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 11/14/2023] [Indexed: 11/19/2023] Open
Abstract
Benign prostatic hyperplasia (BPH) is the nodular proliferation of the prostate transition zone in older men, leading to urinary storage and voiding problems that can be recalcitrant to therapy. Decades ago, John McNeal proposed that BPH originates with the "reawakening" of embryonic inductive activity by adult prostate stroma, which spurs new ductal proliferation and branching morphogenesis. Here, by laser microdissection and transcriptional profiling of the BPH stroma adjacent to hyperplastic branching ducts, we identified secreted factors likely mediating stromal induction of prostate glandular epithelium and coinciding processes. The top stromal factors were insulin-like growth factor 1 (IGF1) and CXC chemokine ligand 13 (CXCL13), which we verified by RNA in situ hybridization to be coexpressed in BPH fibroblasts, along with their cognate receptors (IGF1R and CXCR5) on adjacent epithelium. In contrast, IGF1 but not CXCL13 was expressed in human embryonic prostate stroma. Finally, we demonstrated that IGF1 is necessary for the generation of BPH-1 cell spheroids and patient-derived BPH cell organoids in 3D culture. Our findings partially support historic speculations on the etiology of BPH and provide what we believe to be new molecular targets for rational therapies directed against the underlying processes driving BPH.
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Affiliation(s)
- Anna S Pollack
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Christian A Kunder
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Noah Brazer
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Zhewei Shen
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Sushama Varma
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Robert B West
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Gerald R Cunha
- Department of Urology, University of California, San Francisco (UCSF), San Francisco, California, USA
| | - Laurence S Baskin
- Department of Urology, University of California, San Francisco (UCSF), San Francisco, California, USA
| | - James D Brooks
- Department of Urology, Stanford University School of Medicine, Stanford, California, USA
| | - Jonathan R Pollack
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
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Melnik BC. Acne Transcriptomics: Fundamentals of Acne Pathogenesis and Isotretinoin Treatment. Cells 2023; 12:2600. [PMID: 37998335 PMCID: PMC10670572 DOI: 10.3390/cells12222600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 11/05/2023] [Accepted: 11/08/2023] [Indexed: 11/25/2023] Open
Abstract
This review on acne transcriptomics allows for deeper insights into the pathogenesis of acne and isotretinoin's mode of action. Puberty-induced insulin-like growth factor 1 (IGF-1), insulin and androgen signaling activate the kinase AKT and mechanistic target of rapamycin complex 1 (mTORC1). A Western diet (hyperglycemic carbohydrates and milk/dairy products) also co-stimulates AKT/mTORC1 signaling. The AKT-mediated phosphorylation of nuclear FoxO1 and FoxO3 results in their extrusion into the cytoplasm, a critical switch which enhances the transactivation of lipogenic and proinflammatory transcription factors, including androgen receptor (AR), sterol regulatory element-binding transcription factor 1 (SREBF1), peroxisome proliferator-activated receptor γ (PPARγ) and signal transducer and activator of transcription 3 (STAT3), but reduces the FoxO1-dependent expression of GATA binding protein 6 (GATA6), the key transcription factor for infundibular keratinocyte homeostasis. The AKT-mediated phosphorylation of the p53-binding protein MDM2 promotes the degradation of p53. In contrast, isotretinoin enhances the expression of p53, FoxO1 and FoxO3 in the sebaceous glands of acne patients. The overexpression of these proapoptotic transcription factors explains isotretinoin's desirable sebum-suppressive effect via the induction of sebocyte apoptosis and the depletion of BLIMP1(+) sebocyte progenitor cells; it also explains its adverse effects, including teratogenicity (neural crest cell apoptosis), a reduced ovarian reserve (granulosa cell apoptosis), the risk of depression (the apoptosis of hypothalamic neurons), VLDL hyperlipidemia, intracranial hypertension and dry skin.
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Affiliation(s)
- Bodo C Melnik
- Department of Dermatology, Environmental Medicine and Health Theory, University of Osnabrück, 49069 Osnabrück, Germany
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Platelet-Rich Plasma as an Alternative to Xenogeneic Sera in Cell-Based Therapies: A Need for Standardization. Int J Mol Sci 2022; 23:ijms23126552. [PMID: 35742995 PMCID: PMC9223511 DOI: 10.3390/ijms23126552] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 06/09/2022] [Accepted: 06/10/2022] [Indexed: 12/12/2022] Open
Abstract
There has been an explosion in scientific interest in using human-platelet-rich plasma (PRP) as a substitute of xenogeneic sera in cell-based therapies. However, there is a need to create standardization in this field. This systematic review is based on literature searches in PubMed and Web of Science databases until June 2021. Forty-one studies completed the selection criteria. The composition of PRP was completely reported in less than 30% of the studies. PRP has been used as PRP-derived supernatant or non-activated PRP. Two ranges could be identified for platelet concentration, the first between 0.14 × 106 and 0.80 × 106 platelets/µL and the second between 1.086 × 106 and 10 × 106 platelets/µL. Several studies have pooled PRP with a pool size varying from four to nine donors. The optimal dose for the PRP or PRP supernatant is 10%. PRP or PRP-derived supernatants a have positive effect on MSC colony number and size, cell proliferation, cell differentiation and genetic stability. The use of leukocyte-depleted PRP has been demonstrated to be a feasible alternative to xenogeneic sera. However, there is a need to improve the description of the PRP preparation methodology as well as its composition. Several items are identified and reported to create guidelines for future research.
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Identification of key sex-specific pathways and genes in the subcutaneous adipose tissue from pigs using WGCNA method. BMC Genom Data 2022; 23:35. [PMID: 35538407 PMCID: PMC9086418 DOI: 10.1186/s12863-022-01054-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 05/04/2022] [Indexed: 02/08/2023] Open
Abstract
Background Adipose tissues (ATs), including visceral ATs (VATs) and subcutaneous ATs (SATs), are crucial for maintaining energy and metabolic homeostasis. SATs have been found to be closely related to obesity and obesity-induced metabolic disease. Some studies have shown a significant association between subcutaneous fat metabolism and sexes. However, the molecular mechanisms for this association are still unclear. Here, using the pig as a model, we investigated the systematic association between the subcutaneous fat metabolism and sexes, and identified some key sex-specific pathways and genes in the SATs from pigs. Results The results revealed that 134 differentially expressed genes (DEGs) were identified in female and male pigs from the obese group. A total of 17 coexpression modules were detected, of which six modules were significantly correlated with the sexes (P < 0.01). Among the significant modules, the greenyellow module (cor = 0.68, P < 9e-06) and green module (cor = 0.49, P < 0.003) were most significantly positively correlated with the male and female, respectively. Functional analysis showed that one GO term and four KEGG pathways were significantly enriched in the greenyellow module while six GO terms and six KEGG pathways were significantly enriched in the green module. Furthermore, a total of five and two key sex-specific genes were identified in the two modules, respectively. Two key sex-specific pathways (Ras-MAPK signaling pathway and type I interferon response) play an important role in the SATs of males and females, respectively. Conclusions The present study identified some key sex-specific pathways and genes in the SATs from pigs, which provided some new insights into the molecular mechanism of being involved in fat formation and immunoregulation between pigs of different sexes. These findings may be beneficial to breeding in the pig industry and obesity treatment in medicine. Supplementary Information The online version contains supplementary material available at 10.1186/s12863-022-01054-w.
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Inayet N, Hayat J, Bano G, Poullis A. Gastrointestinal symptoms in acromegaly: A case control study. World J Gastrointest Pharmacol Ther 2020; 11:17-24. [PMID: 32550042 PMCID: PMC7288728 DOI: 10.4292/wjgpt.v11.i2.17] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 05/19/2020] [Accepted: 05/30/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Acromegaly is a chronic disease caused by a pituitary somatotroph adenoma resulting in excess secretion of growth hormone, which leads to excess secretion of Insulin like growth factor 1 from the liver, causing abnormal soft tissue growth. There is increasing awareness that diseases affecting connective tissue are associated with an increase in functional gastrointestinal symptoms. Data was collected from patients with a confirmed diagnosis of acromegaly to evaluate the intensity, variety and impact of abdominal symptoms in comparison with a control group who were healthy participants recruited from the local fracture clinic.
AIM To evaluate the frequency type and burden of abdominal symptoms in acromegaly in comparison with a control group.
METHODS Medical documentation of patients with a diagnosis of acromegaly treated in one tertiary medical centre between 2010 and 2017 has been analysed. Data was collected from patients with confirmed acromegaly, using the Short Form Health Survey (SF36) and Rome IV Diagnostic questionnaire for Functional Gastrointestinal Disorders in Adults (R4DQ) and compared to a sex- and age-matched control group, to assess the burden of abdominal symptoms. Microsoft Excel and IBM SPSS v 25 were used for data analysis.
RESULTS Fifty patients with acromegaly (24 male and 26 females; age range 23-64 years, mean 43) and 200 controls (96 male and 104 females; age range 18-84, mean 42.4) were recruited. 92% (46 out of 50) of patients with acromegaly reported abdominal symptoms and 78% (39 out of 50) had at least one functional gastrointestinal disorder according to the Rome IV diagnostic criteria, compared to 16% of controls (OR > 1, P < 0.0001). The most commonly reported symptom was constipation (69% acromegaly vs 21% of controls OR > 1, P < 0.0001, 95%CI: 4.4–15.8). 34 out of 50 (68%) respondents met the criteria for functional constipation according to Rome IV. Upper gastrointestinal disorders were also more prevalent in the acromegaly group. There was no statistically significant difference in the prevalence of biliary and anorectal symptoms between the two groups. Patients in acromegaly group scored lower on the mean scores of the eight parameters of SF36 Quality of Life questionnaire (mean scores 60.04 vs 71.23, 95%CI: -13.6829 to -8.6971, OR > 1, P < 0.001) as compared to the control group.
CONCLUSION Upper and lower functional gastrointestinal tract disorders (defined by Rome IV diagnostic criteria) are significantly more prevalent in patients with acromegaly compared with healthy age and sex matched controls in our study. Functional constipation is the most commonly reported problem. Poorer quality of life may in part be attributable to the increased prevalence of abdominal symptoms.
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Affiliation(s)
- Nashiz Inayet
- Department of Gastroenterology, St Georges Hospital and St Georges, University of London, London SW17 0QT, United Kingdom
| | - Jamal Hayat
- Department of Gastroenterology, St Georges Hospital and St Georges, University of London, London SW17 0QT, United Kingdom
| | - Gul Bano
- Department of Endocrinology, St Georges Hospital and St Georges, University of London, London SW17 0QT, United Kingdom
| | - Andrew Poullis
- Department of Gastroenterology, St Georges Hospital and St Georges, University of London, London SW17 0QT, United Kingdom
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Senapati P, Kato H, Lee M, Leung A, Thai C, Sanchez A, Gallagher EJ, LeRoith D, Seewaldt VL, Ann DK, Schones DE. Hyperinsulinemia promotes aberrant histone acetylation in triple-negative breast cancer. Epigenetics Chromatin 2019; 12:44. [PMID: 31315653 PMCID: PMC6636093 DOI: 10.1186/s13072-019-0290-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 07/07/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Hyperinsulinemia, the presence of excess insulin relative to glucose in the blood, is considered to be a poor prognostic indicator for patients with triple-negative breast cancer (TNBC). mTOR, a downstream effector of insulin, enhances mitochondrial biogenesis and activity, thereby increasing acetyl-CoA precursors. Increased acetyl-CoA can, in turn, be utilized by nuclear acetyltransferases for histone acetylation, a critical feature of genome regulation. While signaling pathways downstream of insulin have been established for sometime, the effect of insulin on chromatin remains unclear. We hypothesized that hyperinsulinemia-induced metabolic changes lead to genome-wide changes in histone acetylation in TNBC. RESULTS MDA-MB-231 cells were xenografted into hyperinsulinemic and wild-type mice. Tumors in the hyperinsulinemic mice displayed elevated levels of histone acetylation compared to tumors in normal insulin conditions. We show that insulin treatment in vitro leads to global increase in chromatin-associated histone acetylation, in particular at H3K9, through the PI3K/AKT/mTOR pathway. Genome-wide analyses revealed that most promoter regions have an increase in histone acetylation upon insulin treatment. In addition, insulin induces higher levels of reactive oxygen species and DNA damage foci in cells. CONCLUSIONS These results demonstrate the impact of hyperinsulinemia on altered gene regulation through chromatin and the importance of targeting hyperinsulinemia-induced processes that lead to chromatin dysfunction in TNBC.
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Affiliation(s)
- Parijat Senapati
- Department of Diabetes Complications and Metabolism, Beckman Research Institute, City of Hope, Duarte, CA 91010 USA
| | - Hiroyuki Kato
- Department of Diabetes Complications and Metabolism, Beckman Research Institute, City of Hope, Duarte, CA 91010 USA
| | - Michael Lee
- Department of Diabetes Complications and Metabolism, Beckman Research Institute, City of Hope, Duarte, CA 91010 USA
- Irell & Manella Graduate School of Biological Sciences, City of Hope, Duarte, CA USA
| | - Amy Leung
- Department of Diabetes Complications and Metabolism, Beckman Research Institute, City of Hope, Duarte, CA 91010 USA
| | - Christine Thai
- Department of Population Sciences, Beckman Research Institute, City of Hope, Duarte, CA 91010 USA
| | - Angelica Sanchez
- Department of Population Sciences, Beckman Research Institute, City of Hope, Duarte, CA 91010 USA
| | - Emily J. Gallagher
- Division of Endocrinology, Diabetes and Bone Diseases, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
| | - Derek LeRoith
- Division of Endocrinology, Diabetes and Bone Diseases, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
| | - Victoria L. Seewaldt
- Irell & Manella Graduate School of Biological Sciences, City of Hope, Duarte, CA USA
- Department of Population Sciences, Beckman Research Institute, City of Hope, Duarte, CA 91010 USA
| | - David K. Ann
- Department of Diabetes Complications and Metabolism, Beckman Research Institute, City of Hope, Duarte, CA 91010 USA
- Irell & Manella Graduate School of Biological Sciences, City of Hope, Duarte, CA USA
| | - Dustin E. Schones
- Department of Diabetes Complications and Metabolism, Beckman Research Institute, City of Hope, Duarte, CA 91010 USA
- Irell & Manella Graduate School of Biological Sciences, City of Hope, Duarte, CA USA
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Camera DM. Anabolic Heterogeneity Following Resistance Training: A Role for Circadian Rhythm? Front Physiol 2018; 9:569. [PMID: 29875682 PMCID: PMC5974096 DOI: 10.3389/fphys.2018.00569] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 04/30/2018] [Indexed: 02/05/2023] Open
Abstract
It is now well established that resistance exercise stimulates muscle protein synthesis and promotes gains in muscle mass and strength. However, considerable variability exists following standardized resistance training programs in the magnitude of muscle cross-sectional area and strength responses from one individual to another. Several studies have recently posited that alterations in satellite cell population, myogenic gene expression and microRNAs may contribute to individual variability in anabolic adaptation. One emerging factor that may also explain the variability in responses to resistance exercise is circadian rhythms and underlying molecular clock signals. The molecular clock is found in most cells within the body, including skeletal muscle, and principally functions to optimize the timing of specific cellular events around a 24 h cycle. Accumulating evidence investigating the skeletal muscle molecular clock indicates that exercise-induced contraction and its timing may regulate gene expression and protein synthesis responses which, over time, can influence and modulate key physiological responses such as muscle hypertrophy and increased strength. Therefore, the circadian clock may play a key role in the heterogeneous anabolic responses with resistance exercise. The central aim of this Hypothesis and Theory is to discuss and propose the potential interplay between the circadian molecular clock and established molecular mechanisms mediating muscle anabolic responses with resistance training. This article begins with a current review of the mechanisms associated with the heterogeneity in muscle anabolism with resistance training before introducing the molecular pathways regulating circadian function in skeletal muscle. Recent work showing members of the core molecular clock system can regulate myogenic and translational signaling pathways is also discussed, forming the basis for a possible role of the circadian clock in the variable anabolic responses with resistance exercise.
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Affiliation(s)
- Donny M Camera
- Exercise and Nutrition Research Program, Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
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S-nitrosylation of the IGF-1 receptor disrupts the cell proliferative action of IGF-1. Biochem Biophys Res Commun 2017; 491:870-875. [PMID: 28709872 DOI: 10.1016/j.bbrc.2017.06.177] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 06/28/2017] [Indexed: 12/13/2022]
Abstract
The insulin-like growth factor 1 receptor (IGF-1R) is a disulfide-linked heterotetramer containing two α-subunits and two β-subunits. Earlier studies demonstrate that nitric oxide (NO) can adversely affect IGF-1 action in the central nervous system. It is known that NO can induce S-nitrosylation of the cysteine residues in proteins, thereby partly contributing to the regulation of protein function. In the present study, we sought to determine whether S-nitrosylation of the cysteine residues in IGF-1R is an important post-translational modification that regulates its response to IGF-1. Using cultured SH-SY5Y human neuroblastoma cells as an in vitro model, we found that treatment of cells with S-nitroso-cysteine (SNOC), a NO donor that can nitrosylate the cysteine residues in proteins, induces S-nitrosylation of the β subunit of IGF-1R but not its α-subunit. IGF-1Rβ S-nitrosylation by SNOC is coupled with increased dissociation of the IGF-1R protein complex. In addition, disruption of the IGF-1R function resulting from S-nitrosylation of the IGF-1Rβ subunit is associated with disruption of the phosphoinositide 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) signaling pathways. Further, we observed that SNOC-induced IGF-1Rβ S-nitrosylation results in a dose-dependent inhibition of cell proliferation and survival. Together, these results suggest that elevated nitrosative stress may result in dysfunction of cellular IGF-1R signaling through S-nitrosylation of the cysteine residues in the IGF-1Rβ subunit, thereby disrupting the downstream PI3K and MAPK signaling functions and ultimately resulting in inhibition of cell proliferation and survival.
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Karakose M, Pinarli FA, Arslan MS, Boyuk G, Boztok B, Albayrak A, Ulus AT, Cakal E, Delibasi T. Comparison of the Ovary and Kidney as Sites for Islet Transplantation in Diabetic Rats. Transplant Proc 2016; 48:2216-20. [PMID: 27569973 DOI: 10.1016/j.transproceed.2016.04.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 03/30/2016] [Accepted: 04/25/2016] [Indexed: 11/29/2022]
Abstract
BACKGROUND Currently, the most commonly used site for clinical islet transplantation is the liver although it is far from being an ideal site. Low oxygen tension and the induction of an inflammatory response impair islet implantation and lead to significant early loss of islet. The present study aimed to investigate and compare the efficacy of islet transplantation to the ovary and kidney subcapsule in diabetic rats. METHODS The study was performed with 3 groups of rats (control, ovary, and kidney subcapsule) including 6 Sprague female rats each. Diabetes model was created with the use of streptozotocin, and blood glucose levels of the rats were measured after 72 hours. Thirty days after the transplantation, blood samples were obtained from the rats, and then pancreas, kidney, and ovary specimens were fixed in 10% formaldehyde and the experiment completed. After staining with hematoxylin and eosin, the tissue samples were morphologically evaluated by a specialist histopathologist. RESULTS Changes in mean blood glucose and C-peptide levels were statistically significant in the ovary and kidney subcapsule groups. Histologic examination revealed that granulosus insulin-bearing cells were detected in the islet grafts of both ovary and kidney subcapsule groups. The renal subcapsule group had inflammation signs on histologic examination. The islet cells of both ovary and renal subcapsule groups had no vacuolization. CONCLUSIONS We showed that the ovary might be a new site for islet transplantation. Further research should be done on whether the initial results of this study can be reproduced in larger numbers of animal models and eventually in humans.
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Affiliation(s)
- M Karakose
- Department of Endocrinology and Metabolism, Diskapi Yildirim Beyazit Training and Research Hospital, Ankara, Turkey.
| | - F A Pinarli
- Department of Genetic and Medical Research Center, Diskapi Yildirim Beyazit Training and Research Hospital, Ankara, Turkey
| | - M S Arslan
- Department of Endocrinology and Metabolism, Diskapi Yildirim Beyazit Training and Research Hospital, Ankara, Turkey
| | - G Boyuk
- Adacell Laboratory, Pancreas Islet Cell Research Center, Diskapi Yildirim Beyazit Training and Research Hospital, Ankara, Turkey
| | - B Boztok
- Adacell Laboratory, Pancreas Islet Cell Research Center, Diskapi Yildirim Beyazit Training and Research Hospital, Ankara, Turkey
| | - A Albayrak
- Department of Pathology, Diskapi Yildirim Beyazit Training and Research Hospital, Ankara, Turkey
| | - A T Ulus
- Department of Cardiovascular Surgery, Hacettepe University School of Medicine, Ankara, Turkey
| | - E Cakal
- Department of Endocrinology and Metabolism, Diskapi Yildirim Beyazit Training and Research Hospital, Ankara, Turkey
| | - T Delibasi
- Department of Internal Medicine, Kastamonu University School of Medicine, Kastamonu, Turkey
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11
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Azad AKM, Lee H. Voting-based cancer module identification by combining topological and data-driven properties. PLoS One 2013; 8:e70498. [PMID: 23940583 PMCID: PMC3734239 DOI: 10.1371/journal.pone.0070498] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 06/19/2013] [Indexed: 12/19/2022] Open
Abstract
Recently, computational approaches integrating copy number aberrations (CNAs) and gene expression (GE) have been extensively studied to identify cancer-related genes and pathways. In this work, we integrate these two data sets with protein-protein interaction (PPI) information to find cancer-related functional modules. To integrate CNA and GE data, we first built a gene-gene relationship network from a set of seed genes by enumerating all types of pairwise correlations, e.g. GE-GE, CNA-GE, and CNA-CNA, over multiple patients. Next, we propose a voting-based cancer module identification algorithm by combining topological and data-driven properties (VToD algorithm) by using the gene-gene relationship network as a source of data-driven information, and the PPI data as topological information. We applied the VToD algorithm to 266 glioblastoma multiforme (GBM) and 96 ovarian carcinoma (OVC) samples that have both expression and copy number measurements, and identified 22 GBM modules and 23 OVC modules. Among 22 GBM modules, 15, 12, and 20 modules were significantly enriched with cancer-related KEGG, BioCarta pathways, and GO terms, respectively. Among 23 OVC modules, 19, 18, and 23 modules were significantly enriched with cancer-related KEGG, BioCarta pathways, and GO terms, respectively. Similarly, we also observed that 9 and 2 GBM modules and 15 and 18 OVC modules were enriched with cancer gene census (CGC) and specific cancer driver genes, respectively. Our proposed module-detection algorithm significantly outperformed other existing methods in terms of both functional and cancer gene set enrichments. Most of the cancer-related pathways from both cancer data sets found in our algorithm contained more than two types of gene-gene relationships, showing strong positive correlations between the number of different types of relationship and CGC enrichment -values (0.64 for GBM and 0.49 for OVC). This study suggests that identified modules containing both expression changes and CNAs can explain cancer-related activities with greater insights.
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Affiliation(s)
- A. K. M. Azad
- School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Hyunju Lee
- School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju, South Korea
- * E-mail:
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12
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Madathil SK, Carlson SW, Brelsfoard JM, Ye P, D’Ercole AJ, Saatman KE. Astrocyte-Specific Overexpression of Insulin-Like Growth Factor-1 Protects Hippocampal Neurons and Reduces Behavioral Deficits following Traumatic Brain Injury in Mice. PLoS One 2013; 8:e67204. [PMID: 23826235 PMCID: PMC3695083 DOI: 10.1371/journal.pone.0067204] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 05/16/2013] [Indexed: 11/19/2022] Open
Abstract
Traumatic brain injury (TBI) survivors often suffer from long-lasting cognitive impairment that stems from hippocampal injury. Systemic administration of insulin-like growth factor-1 (IGF-1), a polypeptide growth factor known to play vital roles in neuronal survival, has been shown to attenuate posttraumatic cognitive and motor dysfunction. However, its neuroprotective effects in TBI have not been examined. To this end, moderate or severe contusion brain injury was induced in mice with conditional (postnatal) overexpression of IGF-1 using the controlled cortical impact (CCI) injury model. CCI brain injury produces robust reactive astrocytosis in regions of neuronal damage such as the hippocampus. We exploited this regional astrocytosis by linking expression of hIGF-1 to the astrocyte-specific glial fibrillary acidic protein (GFAP) promoter, effectively targeting IGF-1 delivery to vulnerable neurons. Following brain injury, IGF-1Tg mice exhibited a progressive increase in hippocampal IGF-1 levels which was coupled with enhanced hippocampal reactive astrocytosis and significantly greater GFAP levels relative to WT mice. IGF-1 overexpression stimulated Akt phosphorylation and reduced acute (1 and 3d) hippocampal neurodegeneration, culminating in greater neuron survival at 10d after CCI injury. Hippocampal neuroprotection achieved by IGF-1 overexpression was accompanied by improved motor and cognitive function in brain-injured mice. These data provide strong support for the therapeutic efficacy of increased brain levels of IGF-1 in the setting of TBI.
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Affiliation(s)
- Sindhu K. Madathil
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky, United States of America
| | - Shaun W. Carlson
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky, United States of America
| | - Jennifer M. Brelsfoard
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky, United States of America
| | - Ping Ye
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - A. Joseph D’Ercole
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Kathryn E. Saatman
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky, United States of America
- * E-mail:
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Velazquez MA, Hadeler KG, Herrmann D, Kues WA, Rémy B, Beckers JF, Niemann H. In vivo oocyte IGF-1 priming increases inner cell mass proliferation of in vitro-formed bovine blastocysts. Theriogenology 2012; 78:517-27. [PMID: 22538004 DOI: 10.1016/j.theriogenology.2012.02.034] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 01/29/2012] [Accepted: 02/22/2012] [Indexed: 11/29/2022]
Abstract
Studies addressing the effects of supraphysiological levels of IGF-1 on oocyte developmental competence are relevant for unravelling conditions resulting in high bioavailability of IGF-1, such as the polycystic ovary syndrome (PCOS). This study investigated the effects of supraphysiological levels of IGF-1 during in vivo folliculogenesis on the morula-blastocyst transition in bovine embryos. Compacted morulae were non-surgically collected and frozen for subsequent mRNA expression analysis (IGF1R, IGBP3, TP53, AKT1, SLC2A1, SLC2A3, and SLC2A8), or underwent confocal microscopy analysis for protein localization (IGF1R and TP53), or were cultured in vitro for 24 h. In vitro-formed blastocysts were subjected to differential cell staining. The mRNA expression of SLC2A8 was higher in morulae collected from cows treated with IGF-1. Both IGF1R and TP53 protein were present in the plasma membrane and cytoplasm. IGF-1 treatment did not affect protein localization of both IGF1R and TP53. In vitro-formed blastocysts derived from morulae recovered from IGF-1-treated cows displayed a higher number of cells in the inner cell mass (ICM). Total cell number (TCN) of in vitro-formed blastocysts was not affected. A higher mean ICM/TCN proportion was observed in in vitro-formed blastocysts derived from morulae collected from cows treated with IGF-1. The percentage of in vitro-formed blastocysts displaying a low ICM/TCN proportion was decreased by IGF-1 treatment. In vitro-formed blastocysts with a high ICM/TCN proportion were only detected in IGF-1 treated cows. Results show that even a short in vivo exposure of oocytes to a supraphysiological IGF-1 microenvironment can increase ICM cell proliferation in vitro during the morula to blastocyst transition.
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Affiliation(s)
- M A Velazquez
- Institute of Farm Animal Genetics, Biotechnology, Friedrich-Loeffler-Institut, Höltystraße 10, Mariensee, 31535 Neustadt, Germany
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14
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Macedo A, Moriggi M, Vasso M, De Palma S, Sturnega M, Friso G, Gelfi C, Giacca M, Zacchigna S. Enhanced athletic performance on multisite AAV-IGF1 gene transfer coincides with massive modification of the muscle proteome. Hum Gene Ther 2012; 23:146-57. [PMID: 22017471 DOI: 10.1089/hum.2011.157] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Progress in gene therapy has hinted at the potential misuse of gene transfer in sports to achieve better athletic performance, while escaping from traditional doping detection methods. Suitable animal models are therefore required in order to better define the potential effects and risks of gene doping. Here we describe a mouse model of gene doping based on adeno-associated virus (AAV)-mediated delivery of the insulin-like growth factor-I (IGF-I) cDNA to multiple muscles. This treatment determined marked muscle hypertrophy, neovascularization, and fast-to-slow fiber type transition, similar to endurance exercise. In functional terms, treated mice showed impressive endurance gain, as determined by an exhaustive swimming test. The proteomic profile of the transduced muscles at 15 and 30 days after gene delivery revealed induction of key proteins controlling energy metabolism. At the earlier time point, enzymes controlling glycogen mobilization and anaerobic glycolysis were induced, whereas they were later replaced by proteins required for aerobic metabolism, including enzymes related to the Krebs cycle and oxidative phosphorylation. These modifications coincided with the induction of several structural and contractile proteins, in agreement with the observed histological and functional changes. Collectively, these results give important insights into the biological response of muscles to continuous IGF-I expression in vivo and warn against the potential misuse of AAV-IGF1 as a doping agent.
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Affiliation(s)
- Antero Macedo
- Molecular Medicine Laboratory, International Centre for Genetic Engineering and Biotechnology (ICGEB) , 34149, Trieste, Italy
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Tarabra E, Pelengaris S, Khan M. A simple matter of life and death-the trials of postnatal Beta-cell mass regulation. Int J Endocrinol 2012; 2012:516718. [PMID: 22577380 PMCID: PMC3346985 DOI: 10.1155/2012/516718] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 12/31/2011] [Indexed: 12/17/2022] Open
Abstract
Pancreatic beta-cells, which secrete the hormone insulin, are the key arbiters of glucose homeostasis. Defective beta-cell numbers and/or function underlie essentially all major forms of diabetes and must be restored if diabetes is to be cured. Thus, the identification of the molecular regulators of beta-cell mass and a better understanding of the processes of beta-cell differentiation and proliferation may provide further insight for the development of new therapeutic targets for diabetes. This review will focus on the principal hormones and nutrients, as well as downstream signalling pathways regulating beta-cell mass in the adult. Furthermore, we will also address more recently appreciated regulators of beta-cell mass, such as microRNAs.
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Affiliation(s)
- Elena Tarabra
- School of Life Sciences, Warwick University, Gibbet Hill Road, Coventry CV4 7AL, UK
- *Elena Tarabra:
| | - Stella Pelengaris
- School of Life Sciences, Warwick University, Gibbet Hill Road, Coventry CV4 7AL, UK
| | - Michael Khan
- School of Life Sciences, Warwick University, Gibbet Hill Road, Coventry CV4 7AL, UK
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16
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Filippin-Monteiro FB, de Oliveira EM, Sandri S, Knebel FH, Albuquerque RC, Campa A. Serum amyloid A is a growth factor for 3T3-L1 adipocytes, inhibits differentiation and promotes insulin resistance. Int J Obes (Lond) 2011; 36:1032-9. [PMID: 21986708 PMCID: PMC3419975 DOI: 10.1038/ijo.2011.193] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
BACKGROUND/OBJECTIVES Serum amyloid A (SAA) is an acute-phase protein that has been recently correlated with obesity and insulin resistance. Therefore, we first examined whether human recombinant SAA (rSAA) could affect the proliferation, differentiation and metabolism of 3T3-L1 preadipocytes. DESIGN Preadipocytes were treated with rSAA and analyzed for changes in viability and [³H-methyl]-thymidine incorporation as well as cell cycle perturbations using flow cytometry analysis. The mRNA expression profiles of adipogenic factors during the differentiation protocol were also analyzed using real-time PCR. After differentiation, 2-deoxy-[1,2-³H]-glucose uptake and glycerol release were evaluated. RESULTS rSAA treatment caused a 2.6-fold increase in cell proliferation, which was consistent with the results from flow cytometry showing that rSAA treatment augmented the percentage of cells in the S phase (60.9±0.54%) compared with the control cells (39.8±2.2%, (***) P<0.001). The rSAA-induced cell proliferation was mediated by the ERK1/2 signaling pathway, which was assessed by pretreatment with the inhibitor PD98059. However, the exposure of 3T3-L1 cells to rSAA during the differentiation process resulted in attenuated adipogenesis and decreased expression of adipogenesis-related factors. During the first 72 h of differentiation, rSAA inhibited the differentiation process by altering the mRNA expression kinetics of adipogenic transcription factors and proteins, such as PPARγ2 (peroxisome proliferator-activated receptor γ 2), C/EBPβ (CCAAT/enhancer-binding protein β) and GLUT4. rSAA prevented the intracellular accumulation of lipids and, in fully differentiated cells, increased lipolysis and prevented 2-deoxy-[1,2-³H]-glucose uptake, which favors insulin resistance. Additionally, rSAA stimulated the secretion of proinflammatory cytokines interleukin 6 and tumor necrosis factor α, and upregulated SAA3 mRNA expression during adipogenesis. CONCLUSIONS We showed that rSAA enhanced proliferation and inhibited differentiation in 3T3-L1 preadipocytes and altered insulin sensitivity in differentiated cells. These results highlight the complex role of SAA in the adipogenic process and support a direct link between obesity and its co-morbidities such as type II diabetes.
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Gelmedin V, Brodigan T, Gao X, Krause M, Wang Z, Hawdon JM. Transgenic C. elegans dauer larvae expressing hookworm phospho null DAF-16/FoxO exit dauer. PLoS One 2011; 6:e25996. [PMID: 22016799 PMCID: PMC3189237 DOI: 10.1371/journal.pone.0025996] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 09/15/2011] [Indexed: 01/28/2023] Open
Abstract
Parasitic hookworms and the free-living model nematode Caenorhabtidis elegans share a developmental arrested stage, called the dauer stage in C. elegans and the infective third-stage larva (L3) in hookworms. One of the key transcription factors that regulate entrance to and exit from developmental arrest is the forkhead transcription factor DAF-16/FoxO. During the dauer stage, DAF-16 is activated and localized in the nucleus. DAF-16 is negatively regulated by phosphorylation by the upstream kinase AKT, which causes DAF-16 to localize out of the nucleus and the worm to exit from dauer. DAF-16 is conserved in hookworms, and hypothesized to control recovery from L3 arrest during infection. Lacking reverse genetic techniques for use in hookworms, we used C. elegans complementation assays to investigate the function of Ancylostoma caninum DAF-16 during entrance and exit from L3 developmental arrest. We performed dauer switching assays and observed the restoration of the dauer phenotype when Ac-DAF-16 was expressed in temperature-sensitive dauer defective C. elegans daf-2(e1370);daf-16(mu86) mutants. AKT phosphorylation site mutants of Ac-DAF-16 were also able to restore the dauer phenotype, but surprisingly allowed dauer exit when temperatures were lowered. We used fluorescence microscopy to localize DAF-16 during dauer and exit from dauer in C. elegans DAF-16 mutant worms expressing Ac-DAF-16, and found that Ac-DAF-16 exited the nucleus during dauer exit. Surprisingly, Ac-DAF-16 with mutated AKT phosphorylation sites also exited the nucleus during dauer exit. Our results suggest that another mechanism may be involved in the regulation DAF-16 nuclear localization during recovery from developmental arrest.
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Affiliation(s)
- Verena Gelmedin
- Department of Microbiology, Immunology and Tropical Medicine, George Washington University Medical Center, Washington, D. C., United States of America.
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18
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Anitua E, Alkhraisat MH, Orive G. Perspectives and challenges in regenerative medicine using plasma rich in growth factors. J Control Release 2011; 157:29-38. [PMID: 21763737 DOI: 10.1016/j.jconrel.2011.07.004] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 06/06/2011] [Indexed: 12/18/2022]
Abstract
Plasma rich in growth factors (PRGF-Endoret) is an endogenous therapeutic technology that is gaining interest in regenerative medicine due to its potential to stimulate and accelerate tissue healing and bone regeneration. This autologous biotechnology is designed for the in situ delivery of multiple cellular modulators and the formation of a fibrin scaffold, thereby providing different formulations that can be widely used in numerous medical and scientific fields including dentistry, oral implantology, orthopedics, ulcer treatment and tissue engineering among others. Here we discuss the important progress that has been accomplished in this field. Furthermore, a comprehensive outlook of the intriguing therapeutic applications of this technology is presented.
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Affiliation(s)
- Eduardo Anitua
- Private Practice in Implantology and Oral Rehabilitation in Vitoria, Spain
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19
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Anitua E, Sánchez M, Prado R, Orive G. The P makes the difference in plasma rich in growth factors (PRGF) technology. Platelets 2011; 22:473-4; author reply 475. [DOI: 10.3109/09537104.2011.583999] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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20
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Kim SJ, Nian C, McIntosh CHS. Adipocyte expression of the glucose-dependent insulinotropic polypeptide receptor involves gene regulation by PPARγ and histone acetylation. J Lipid Res 2011; 52:759-70. [PMID: 21245029 PMCID: PMC3053207 DOI: 10.1194/jlr.m012203] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 01/04/2011] [Indexed: 01/17/2023] Open
Abstract
Glucose-dependent insulinotropic polypeptide (GIP) is a gastrointestinal hormone that exerts insulinotropic and growth and survival effects on pancreatic β-cells. Additionally, there is increasing evidence supporting an important role for GIP in the regulation of adipocyte metabolism. In the current study we examined the molecular mechanisms involved in the regulation of GIP receptor (GIPR) expression in 3T3-L1 cells. GIP acted synergistically with insulin to increase neutral lipid accumulation during progression of 3T3-L1 preadipocytes to the adipocyte phenotype. Both GIPR protein and mRNA expression increased during 3T3-L1 cell differentiation, and this increase was associated with upregulation of nuclear levels of sterol response element binding protein 1c (SREBP-1c) and peroxisome proliferator-activated receptor γ (PPARγ), as well as acetylation of histones H3/H4. The PPARγ receptor agonists LY171883 and rosiglitazone increased GIPR expression in differentiated 3T3-L1 adipocytes, whereas the antagonist GW9662 ablated expression. Additionally, both PPARγ and acetylated histones H3/H4 were shown to bind to a region of the GIPR promoter containing the peroxisome proliferator response element (PPRE). Knockdown of PPARγ in differentiated 3T3-L1 adipocytes, using RNA interference, reduced GIPR expression, supporting a functional regulatory role. Taken together, these studies show that GIP and insulin act in a synergistic manner on 3T3-L1 cell development and that adipocyte GIPR expression is upregulated through a mechanism involving interactions between PPARγ and a GIPR promoter region containing an acetylated histone region.
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Affiliation(s)
| | | | - Christopher H. S. McIntosh
- Department of Cellular and Physiological Sciences and the Diabetes Research Group, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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21
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Velazquez MA, Hermann D, Kues WA, Niemann H. Increased apoptosis in bovine blastocysts exposed to high levels of IGF1 is not associated with downregulation of the IGF1 receptor. Reproduction 2011; 141:91-103. [DOI: 10.1530/rep-10-0336] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The hypothesis that high concentrations of IGF1 can impair embryo development was investigated in a bovine in vitro model to reflect conditions in polycystic ovary syndrome (PCOS) patients. Embryos were either cultured in the absence or presence of a physiological (100 ng/ml) or supraphysiological (1000 ng/ml) IGF1 concentration. Cell allocation, apoptosis, transcript and protein expression of selected genes involved in apoptosis, glucose metabolism and the IGF system were analysed. Supraphysiological IGF1 concentration did not improve blastocyst formation over controls, but induced higher levels of apoptosis, decreased TP53 protein expression in the trophectoderm and increased the number of cells in the inner cell mass (ICM). The increase in ICM cells corresponded with an increase in IGF1 receptor (IGF1R) protein in the ICM. A small, but significant, percentage of blastocysts displayed a hypertrophic ICM, not observed in controls and virtually absent in embryos treated with physiological concentrations of IGF1. Physiological IGF1 concentrations increased total IGF1R protein expression and upregulated IGFBP3 transcripts leading to an increase in blastocyst formation with no effects on cell number or apoptosis. In conclusion, the results support the hypothesis of detrimental effects of supraphysiological IGF1 concentrations on early pregnancy. However, our results do not support the premise that increased apoptosis associated with high levels of IGF1 is mediated via downregulation of the IGF1R as previously found in preimplantation mouse embryos. This in vitro system with the bovine preimplantation embryo reflects critical features of fertility in PCOS patients and could thus serve as a useful model for in-depth mechanistic studies.
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22
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Kouroupi G, Lavdas AA, Gaitanou M, Thomaidou D, Stylianopoulou F, Matsas R. Lentivirus-mediated expression of insulin-like growth factor-I promotes neural stem/precursor cell proliferation and enhances their potential to generate neurons. J Neurochem 2010; 115:460-74. [PMID: 20681949 DOI: 10.1111/j.1471-4159.2010.06939.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Strategies to enhance neural stem/precursor cell (NPC) capacity to yield multipotential, proliferative, and migrating pools of cells that can efficiently differentiate into neurons could be crucial for structural repair after neurodegenerative damage. Here, we have generated a lentiviral vector for expression of insulin-like growth factor-I (IGF-1) and investigated the impact of IGF-1 transduction on the properties of cultured NPCs (IGF-1-NPCs). Under proliferative conditions, IGF-1 transduction promoted cell cycle progression via cyclin D1 up-regulation and Akt phosphorylation. Remarkably upon differentiation-inducing conditions, IGF-1-NPCs cease to proliferate and differentiate to a greater extent into neurons with significantly longer neurites, at the expense of astrocytes. Moreover, using live imaging we provide evidence that IGF-1 transduction enhances the motility and tissue penetration of grafted NPCs in cultured cortical slices. These results illustrate the important consequence of IGF-1 transduction in regulating NPC functions and offer a potential strategy to enhance the prospective repair potential of NPCs.
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Affiliation(s)
- Georgia Kouroupi
- Laboratory of Cellular and Molecular Neurobiology, Hellenic Pasteur Institute, Athens, Greece
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23
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GH overexpression causes muscle hypertrophy independent from local IGF-I in a zebrafish transgenic model. Transgenic Res 2010; 20:513-21. [DOI: 10.1007/s11248-010-9429-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Accepted: 07/07/2010] [Indexed: 01/29/2023]
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Bouraoui L, Capilla E, Gutiérrez J, Navarro I. Insulin and insulin-like growth factor I signaling pathways in rainbow trout (Oncorhynchus mykiss) during adipogenesis and their implication in glucose uptake. Am J Physiol Regul Integr Comp Physiol 2010; 299:R33-41. [DOI: 10.1152/ajpregu.00457.2009] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Primary cultures of rainbow trout ( Oncorhynchus mykiss ) adipocytes were used to examine the main signaling pathways of insulin and insulin-like growth factor I (IGF-I) during adipogenesis. We first determined the presence of IGF-I receptors (IGF-IR) and insulin receptors (IR) in trout preadipocytes ( day 5) and adipocytes ( day 14). IGF-IRs were more abundant and appeared to be in higher levels in differentiated cells than in preadipocytes, whereas IRs were detected in lower but constant levels throughout the culture. The cells were immunoreactive against ERK1/2 MAPK, and AKT/PI3K, components of the two main signal transduction pathways for insulin and IGF-I receptors. Stimulation of MAPK phosphorylation by IGF-I was higher in preadipocytes than in adipocytes, while no effects were observed in MAPK phosphorylation after incubation of cells with insulin. AKT phosphorylation increased in the presence of both insulin and IGF-I, with higher levels of stimulation in adipocytes than in preadipocytes. Activation of both pathways was blocked by the use of specific inhibitors of MAPK (PD98059) and AKT (wortmannin). We describe here, for the first time, the effects of IGF-I and insulin on 2-deoxyglucose uptake in primary culture of trout adipocytes. IGF-I was more potent in stimulating glucose uptake than insulin, and PD98059 and wortmannin inhibited the stimulation of glucose uptake by this growth factor, suggesting that IGF-I plays an important metabolic role in trout adipocytes. Our results suggest that differential activation of the MAPK and AKT pathways are involved in the IGF-I- and insulin-induced effects of trout adipocytes during the various stages of adipogenesis.
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Affiliation(s)
- L. Bouraoui
- Departament de Fisiologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - E. Capilla
- Departament de Fisiologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - J. Gutiérrez
- Departament de Fisiologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - I. Navarro
- Departament de Fisiologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
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Differentiation and mineralization of murine mesenchymal C3H10T1/2 cells in micromass culture. Differentiation 2010; 79:211-7. [PMID: 20356667 DOI: 10.1016/j.diff.2010.03.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 02/25/2010] [Accepted: 03/10/2010] [Indexed: 12/28/2022]
Abstract
The murine mesenchymal cell line, C3H10T1/2 in micromass culture undergoes chondrogenic differentiation with the addition of BMP-2. This study compares the use of BMP-2 vs. insulin, transferrin, and sodium selenite (ITS) to create a chondrogenic micromass cell culture system that models cartilage calcification in the presence of 4mM inorganic phosphate. BMP-2 treated cultures showed more intense alcian blue staining for proteoglycans than ITS treated cultures at early time points. Both ITS and BMP-2 treated cultures showed similar mineral deposition in cultures treated with 4mM phosphate via von Kossa staining, however FTIR spectroscopy of cultures showed different matrix properties. ITS treated cultures produced matrix that more closely resembled mouse calcified cartilage by FTIR analysis. (45)Ca uptake curves showed delayed onset of mineralization in cultures treated with BMP-2, however they had an increased rate of mineralization (initial slope of (45)Ca uptake curve) when compared to the cultures treated with ITS. Immunohistochemistry showed the presence of both collagens type I and type II in BMP-2 and ITS treated control (1mM inorganic phosphate) and mineralizing cultures. BMP-2 treated mineralizing cultures displayed more intense staining for collagen type II than all other cultures. Collagen type X staining was detected at Day 9 only in mineralizing cultures treated with ITS. Western blotting of Day 9 cultures confirmed the presence of collagen type X in the mineralizing ITS cultures, and also showed very small amounts of collagen type X in BMP-2 treated cultures and control ITS cultures. By Day 16 all cultures stained positive for collagen type X. These data suggest that BMP-2 induces a more chondrogenic phenotype, while ITS treatment favors maturation and hypertrophy of the chondrocytes in the murine micromass cultures.
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26
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Himpe E, Kooijman R. Insulin-like growth factor-I receptor signal transduction and the Janus Kinase/Signal Transducer and Activator of Transcription (JAK-STAT) pathway. Biofactors 2009; 35:76-81. [PMID: 19319849 DOI: 10.1002/biof.20] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The insulin-like growth factor IGF-I is an important fetal and postnatal growth factor, which is also involved in tissue homeostasis via regulation of proliferation, differentiation, and cell survival. To understand the role of IGF-I in the pathophysiology of a variety of disorders, including growth disorders, cancer, and neurodegenerative diseases, a detailed knowledge of IGF-I signal transduction is required. This knowledge may also contribute to the development of new therapies directed at the IGF-I receptor or other signaling molecules. In this review, we will address IGF-I receptor signaling through the JAK/STAT pathway in IGF-I signaling and the role of cytokine-induced inhibitors of signaling (CIS) and suppressors of cytokine signaling (SOCS). It appears that, in addition to the canonical IGF-I signaling pathways through extracellular-regulated kinase (ERK) and phosphatidylinositol-3 kinase (PI3K)-Akt, IGF-I also signals through the JAK/STAT pathway. Activation of this pathway may lead to induction of SOCS molecules, well-known feedback inhibitors of the JAK/STAT pathway, which also suppress of IGF-I-induced JAK/STAT signaling. Furthermore, other IGF-I-induced signaling pathways may also be modulated by SOCS. It is conceivable that the effect of these classical inhibitors of cytokine signaling directly affect IGF-I receptor signaling, because they are able to associate to the intracellular part of the IGF-I receptor. These observations indicate that CIS and SOCS molecules are key to cross-talk between IGF-I receptor signaling and signaling through receptors belonging to the hematopoietic/cytokine receptor superfamily. Theoretically, dysregulation of CIS or SOCS may affect IGF-I-mediated effects on body growth, cell differentiation, proliferation, and cell survival.
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Affiliation(s)
- Eddy Himpe
- Department of Pharmacology, Medical School, Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, B-1090 Brussels, Belgium
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Insulin-like growth factor-1 attenuates cisplatin-induced γH2AX formation and DNA double-strand breaks repair pathway in non-small cell lung cancer. Cancer Lett 2008; 272:232-41. [DOI: 10.1016/j.canlet.2008.07.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Revised: 03/27/2008] [Accepted: 07/14/2008] [Indexed: 11/23/2022]
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TAKETANI T, YAMAGATA Y, TAKASAKI A, MATSUOKA A, TAMURA H, SUGINO N. Effects of growth hormone and insulin-like growth factor 1 on progesterone production in human luteinized granulosa cells. Fertil Steril 2008; 90:744-8. [DOI: 10.1016/j.fertnstert.2007.07.1304] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2007] [Revised: 06/18/2007] [Accepted: 06/18/2007] [Indexed: 11/26/2022]
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Meadows E, Cho JH, Flynn JM, Klein WH. Myogenin regulates a distinct genetic program in adult muscle stem cells. Dev Biol 2008; 322:406-14. [PMID: 18721801 DOI: 10.1016/j.ydbio.2008.07.024] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2008] [Revised: 07/11/2008] [Accepted: 07/12/2008] [Indexed: 01/28/2023]
Abstract
In contrast to the detailed understanding we have for the regulation of skeletal muscle gene expression in embryos, similar insights into postnatal muscle growth and regeneration are largely inferential or do not directly address gene regulatory mechanisms. Muscle stem cells (satellite cells) are chiefly responsible for providing new muscle during postnatal and adult life. The purpose of this study was to determine the role that the myogenic basic helix-loop-helix regulatory factor myogenin has in postnatal muscle growth and adult muscle stem cell gene expression. We found that myogenin is absolutely required for skeletal muscle development and survival until birth, but it is dispensable for postnatal life. However, Myog deletion after birth led to reduced body size implying a role for myogenin in regulating body homeostasis. Despite a lack of skeletal muscle defects in Myog-deleted mice during postnatal life and the efficient differentiation of cultured Myog-deleted adult muscle stem cells, the loss of myogenin profoundly altered the pattern of gene expression in cultured muscle stem cells and adult skeletal muscle. Remarkably, these changes in gene expression were distinct from those found in Myog-null embryonic skeletal muscle, indicating that myogenin has separate functions during postnatal life.
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Affiliation(s)
- Eric Meadows
- Department of Biochemistry and Molecular Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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Hauck SM, Gloeckner CJ, Harley ME, Schoeffmann S, Boldt K, Ekstrom PAR, Ueffing M. Identification of paracrine neuroprotective candidate proteins by a functional assay-driven proteomics approach. Mol Cell Proteomics 2008; 7:1349-61. [PMID: 18436526 DOI: 10.1074/mcp.m700456-mcp200] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glial cells support neuronal survival and function by secreting neurotrophic cytokines. Retinal Mueller glial cells (RMGs) support retinal neurons, especially photoreceptors. These highly light-sensitive sensory neurons receive vision, and their death results in blinding diseases. It has been proposed that RMGs release factors that support photoreceptor survival, but the nature of these factors remains to be elucidated. To discover such neurotrophic factors, we developed an integrated work flow toward systematic identification of neuroprotective proteins, which are, like most cytokines, expressed only in minute amounts. This strategy can be generally applied to identify secreted bioactive molecules from any body fluid once a recipient cell for this activity is known. Toward this goal we first isolated conditioned medium (CM) from primary porcine RMGs cultured in vitro and tested for survival-promoting activity using primary photoreceptors. We then developed a large scale, microplate-based cellular high content assay that allows rapid assessment of primary photoreceptor survival concomitant with biological activity in vitro. The enrichment strategy of bioactive proteins toward their identification consists of several fractionation steps combined with tests for biological function. Here we combined 1) size fractionation, 2) ion exchange chromatography, 3) reverse phase liquid chromatography, and 4) mass spectrometry (Q-TOF MS/MS or MALDI MS/MS) for protein identification. As a result of this integrated work flow, the insulin-like growth factor-binding proteins IGFBP5 and IGFBP7 and connective tissue growth factor (CTGF) were identified as likely candidates. Cloning and stable expression of these three candidate factors in HEK293 cells produced conditioned medium enriched for either one of the factors. IGFBP5 and CTGF, but not IGFBP7, significantly increased photoreceptor survival when secreted from HEK293 cells and when added to the original RMG-CM. This indicates that the survival-promoting activity in RMG-CM is multifactorial with IGFBP5 and CTGF as an integral part of this activity.
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Affiliation(s)
- Stefanie M Hauck
- Institute of Human Genetics, Helmholtz Zentrum Muenchen-German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany.
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Davie JK, Cho JH, Meadows E, Flynn JM, Knapp JR, Klein WH. Target gene selectivity of the myogenic basic helix–loop–helix transcription factor myogenin in embryonic muscle. Dev Biol 2007; 311:650-64. [PMID: 17904117 DOI: 10.1016/j.ydbio.2007.08.014] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Revised: 07/04/2007] [Accepted: 08/07/2007] [Indexed: 01/30/2023]
Abstract
The myogenic regulatory factors MyoD and myogenin are crucial for skeletal muscle development. Despite their importance, the mechanisms by which these factors selectively regulate different target genes are unclear. The purpose of the present investigation was to compare embryonic skeletal muscle from myogenin(+/+) and myogenin(-/-) mice to identify genes whose expression was dependent on the presence of myogenin but not MyoD and to determine whether myogenin-binding sites could be found within regulatory regions of myogenin-dependent genes independent of MyoD. We identified a set of 140 muscle-expressed genes whose expression in embryonic tongue muscle of myogenin(-/-) mice was downregulated in the absence of myogenin, but in the presence of MyoD. Myogenin bound within conserved regulatory regions of several of the downregulated genes, but MyoD bound only to a subset of these same regions, suggesting that many downregulated genes were selective targets of myogenin. The regulatory regions activated gene expression in cultured myoblasts and fibroblasts overexpressing myogenin or MyoD, indicating that expression from exogenously introduced DNA could not recapitulate the selectivity for myogenin observed in vivo. The results identify new target genes for myogenin and show that myogenin's target gene selectivity is not based solely on binding site sequences.
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Affiliation(s)
- Judith K Davie
- Department of Biochemistry and Molecular Biology, Unit 1000, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA
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32
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Partanen SE. Prostatic-like acid phosphatase in human endometrial glands and its cyclic activity. J Mol Histol 2007; 39:143-52. [DOI: 10.1007/s10735-007-9147-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2007] [Accepted: 09/27/2007] [Indexed: 10/22/2022]
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Abstract
1. The composition of synthetic cell culture media is important for the behaviour of cultured cells in vitro and may affect the results of many in vitro experiments. The total anti-oxidant capacity (TAC) of an extracellular medium may be an important factor in cell redox homeostasis. 2. In the present study, the TAC of cell culture media used for the cultivation of mammalian, yeast and bacterial cells (RPMI1640, Iscove's modified Dulbecco's medium, Dulbecco's modified Eagle's medium, minimum essential medium Eagle's 1959 with Earle's salts, Parker medium 199 with Hanks salts, bacterial Luria-Bertani medium, yeast extract-peptone-glucose and yeast nitrogen base media) was estimated using the 2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS(.+)) decolourization assay and the ferric ion reducing anti-oxidant power assay. 3. We found that components of the media such as cysteine, tyrosine, tryptophan and Phenol Red are important contributors to the TAC of cell culture media.
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Affiliation(s)
- Anna Lewinska
- Department of Biochemistry and Cell Biology, University of Rzeszow, Rzeszow, Poland.
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Xie L, Jiang Y, Ouyang P, Chen J, Doan H, Herndon B, Sylvester JE, Zhang K, Molteni A, Reichle M, Zhang R, Haub MD, Baybutt RC, Wang W. Effects of dietary calorie restriction or exercise on the PI3K and Ras signaling pathways in the skin of mice. J Biol Chem 2007; 282:28025-35. [PMID: 17646168 DOI: 10.1074/jbc.m604857200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Weight control by exercise and dietary calorie restriction (DCR) has been associated with reduced cancer risk, but the underlying mechanisms are not well understood. This study was designed to compare the effects of weight loss by increasing physical activity or decreasing calorie intake on tumor promoter-induced Ras-MAPK and PI3K-Akt pathways. SENCAR mice were randomly assigned to one of the following five groups: ad libitum-fed sedentary control, ad libitum-fed exercise (AL+Exe), exercise but pair-fed at the amount as controls (PF+Exe), 20% DCR, and 20% DCR plus exercise (DCR+Exe). After 10 weeks, body weight and body fat significantly decreased in the groups of DCR, DCR+Exe, and PF+Exe when compared with the controls. AL+Exe did not induce weight loss due to, at least in part, increased food intake. Plasma IGF-1 levels reduced significantly in DCR and DCR+Exe but not PF+Exe. The protein H-Ras and activated Ras-GTP significantly decreased in TPA-induced skin tissues of DCR-fed mice but not exercised mice. PI3K protein, phosphoserine Akt, and p42/p44-MAPK were reduced, however, in both DCR and PF+Exe groups. Immunohistochemistry demonstrated that the significantly reduced H-Ras occurred in subcutaneous fat cells, while the reduced PI3K and PCNA took place only in the epidermis. Plasma leptin decreased in PF+Exe, DCR, and DCR+Exe, while the caspase-3 activity increased in DCR+Exe only. Genomic microarray analysis further indicated that the expression of 34 genes relevant to PI3K and 31 genes to the MAPK pathway were significantly regulated by either DCR or PF+Exe treatments. The reduced PI3K in PF+Exe mice was partially reversed by IGF-1 treatment. The overall results of this study demonstrated that DCR abrogated both Ras and PI3K signaling, which might inhibit TPA-induced proliferation and anti-apoptosis. Selective inhibition of PI3K by PF+Exe but not AL+Exe seems more attributable to the magnitude of the caloric deficit and/or body fat loss than diet versus exercise comparison.
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Affiliation(s)
- Linglin Xie
- Department of Human Nutrition and Statistics, Kansas State University, Manhattan, Kansas 66506, USA
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35
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Douglas RS, Gianoukakis AG, Kamat S, Smith TJ. Aberrant expression of the insulin-like growth factor-1 receptor by T cells from patients with Graves' disease may carry functional consequences for disease pathogenesis. THE JOURNAL OF IMMUNOLOGY 2007; 178:3281-7. [PMID: 17312178 DOI: 10.4049/jimmunol.178.5.3281] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Graves' disease (GD), an autoimmune process involving thyroid and orbital tissue, is associated with lymphocyte abnormalities including expansion of memory T cells. Insulin-like growth factor receptor-1 (IGF-1R)-bearing fibroblasts overpopulate connective tissues in GD. IGF-1R on fibroblasts, when ligated with IgGs from these patients, results in the expression of the T cell chemoattractants, IL-16 and RANTES. We now report that a disproportionately large fraction of peripheral blood T cells express IGF-1R (CD3+IGF-R+). CD3+IGF-1R+ T cells comprise 48 +/- 4% (mean +/- SE; n = 33) in patients with GD compared with 15 +/- 3% (n = 21; p < 10(-8)) in controls. This increased population of IGF-1R+ T cells results, at least in part, from an expansion of CD45RO+ T cells expressing the receptor. In contrast, the fraction of CD45RA+IGF-1R+ T cells is similar in GD and controls. T cells harvested from affected orbital tissues in GD reflect similar differences in the proportion of IGF-1R+CD3+ and IGF-1R+CD4+CD3+ cells as those found in the peripheral circulation. GD-derived peripheral T cells express durable, constitutive IGF-1R expression in culture and receptor levels are further up-regulated following CD3 complex activation. IGF-1 enhanced GD-derived T cell incorporation of BrdU (p < 0.02) and inhibited Fas-mediated apoptosis (p < 0.02). These findings suggest a potential role for IGF-1R displayed by lymphocytes in supporting the expansion of memory T cells in GD.
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Affiliation(s)
- Raymond S Douglas
- Department of Medicine, Division of Molecular Medicine, Harbor-University of California Los Angeles Medical Center, 1124 West Carson Street, Torrance, CA 90502, USA
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Holzman JL, Liu L, Duke BJ, Kemendy AE, Eaton DC. Transactivation of the IGF-1R by aldosterone. Am J Physiol Renal Physiol 2007; 292:F1219-28. [PMID: 17190911 DOI: 10.1152/ajprenal.00214.2006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Activation of epithelial sodium channels (ENaC) by aldosterone, insulin, or insulin-like growth factor-1 (IGF-1) in renal epithelial cells (including the Xenopus laevis renal cell line A6) appears to share some common signaling elements subsequent to the initial insulin or IGF-1 receptor activation. Previously, the convergence point for insulin or IGF-1 and aldosterone signaling was assumed to be downstream of the receptor at the level of phosphatidylinositol 3-kinase (PI3-K); however, this study shows aldosterone directly transactivates the IGF-1 receptor (IGF-1R). In A6 cells, 10-min exposure to aldosterone increased the phosphorylation of the IGF-1 receptor, insulin receptor substrate-1 (IRS-1), and Akt (PKB). Furthermore, aldosterone activated PI3-K and phosphorylation of the most downstream element, Akt, was blocked by the specific PI3-K inhibitor LY-294002. Transactivation requires aldosterone binding to the mineralocorticoid/glucocorticoid receptor and does not require transcription.
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Affiliation(s)
- Jennifer L Holzman
- Emory Univ. School of Medicine, Dept. of Medicine, Renal Div., 1639 Pierce Dr., Rm. 3327, Atlanta, GA 30322, USA.
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Wu J, Wang B, Zhang H, Yu T, Yang G. Different transcription profiles of SOCS-3, ob and IGF-I genes and their possible correlations in obese and lean pigs. Acta Biochim Biophys Sin (Shanghai) 2007; 39:305-10. [PMID: 17417687 DOI: 10.1111/j.1745-7270.2007.00274.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Pig breeds have significant differences in fat deposition and muscle development ability. However, the molecular mechanism behind these differences is still unknown. In this study, the expression patterns of three candidate genes, suppressor of cytokine signaling 3 (SOCS-3), obesity (ob) and insulin-like growth factor I (IGF-I), which are involved in adipose metabolism or muscle development, were analyzed. Total RNA was extracted from dorsal subcutaneous adipose tissue and longissimus of 8-month-old Bamei and Largewhite pigs. Semiquantitative reverse transcription-polymerase chain reaction was used to determine the expression levels of the SOCS-3 and ob genes in adipose tissue, and SOCS-3 and IGF-I genes in muscle tissue. The results showed that in adipose tissue the expression level of SOCS-3 was significantly higher in Bamei (obese) pigs than that in Largewhite (lean) pigs (P<0.01). However, in muscle tissue it was significantly lower in Bamei than that in Largewhite pigs (P<0.01). Furthermore, the expression of SOCS-3 was positively correlated to that of ob in adipose tissue and that of IGF-I in muscle tissue. These findings suggest that the difference in SOCS-3 gene expression levels in adipose and muscle tissues, the relationship between SOCS-3 and ob in adipose tissue, and that between SOCS-3 and IGF-I in muscle tissue, might contribute to the different fat deposition and muscle development ability between obese and lean pigs.
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Affiliation(s)
- Jiangwei Wu
- Laboratory of Animal Fat Deposition and Muscle Development, Northwest A&F University, Yangling 712100, China
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38
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Bamman MM, Petrella JK, Kim JS, Mayhew DL, Cross JM. Cluster analysis tests the importance of myogenic gene expression during myofiber hypertrophy in humans. J Appl Physiol (1985) 2007; 102:2232-9. [PMID: 17395765 DOI: 10.1152/japplphysiol.00024.2007] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
We applied K-means cluster analysis to test the hypothesis that muscle-specific factors known to modulate protein synthesis and satellite cell activity would be differentially expressed during progressive resistance training (PRT, 16 wk) in 66 human subjects experiencing extreme, modest, and failed myofiber hypertrophy. Muscle mRNA expression of IGF-I isoform Ea (IGF-IEa), mechanogrowth factor (MGF, IGF-IEc), myogenin, and MyoD were assessed in muscle biopsies collected at baseline (T1) and 24 h after the first (T2) and last (T3) loading bouts from previously untrained subjects clustered as extreme responders (Xtr, n=17), modest responders (Mod, n=32), and nonresponders (Non, n=17) based on mean myofiber hypertrophy. Myofiber growth averaged 2,475 microm2 in Xtr, 1,111 microm2 in Mod, and -16 microm2 in Non. Main training effects revealed increases in all transcripts (46-83%, P<0.005). For the entire cohort, IGF-IEa, MGF, and myogenin mRNAs were upregulated by T2 (P<0.05), while MyoD did not increase significantly until T3 (P<0.001). Within clusters, MGF and myogenin upregulation was robust in Xtr (126% and 65%) and Mod (73% and 41%) vs. no changes in Non. While significant in all clusters by T3, IGF-IEa increased most in Xtr (105%) and least in Non (44%). Although MyoD expression increased overall, no changes within clusters were detected. We reveal for the first time that MGF and myogenin transcripts are differentially expressed in subjects experiencing varying degrees of PRT-mediated myofiber hypertrophy. The data strongly suggest the load-mediated induction of these genes may initiate important actions necessary to promote myofiber growth during PRT, while the role of MyoD is less clear.
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Affiliation(s)
- Marcas M Bamman
- Department of Physiology and Biophysics, Medical Scientist Training Program, The University of Alabama at Birmingham, and Core Muscle Research Laboratory, GRECC/11G, Veterans Affairs Medical Center, AL 35294-0001, USA.
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39
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Montserrat N, Gabillard JC, Capilla E, Navarro MI, Gutiérrez J. Role of insulin, insulin-like growth factors, and muscle regulatory factors in the compensatory growth of the trout (Oncorhynchus mykiss). Gen Comp Endocrinol 2007; 150:462-72. [PMID: 17196198 DOI: 10.1016/j.ygcen.2006.11.009] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2006] [Revised: 11/12/2006] [Accepted: 11/14/2006] [Indexed: 11/19/2022]
Abstract
To examine the various mechanisms involved in compensatory growth in Oncorhynchus mykiss, an experimental protocol involving 1, 2 or 4 weeks of fasting followed by a single ad libitum re-feeding period of 4 weeks was designed for alevins. Morphological parameters including body weight, specific growth rates (SGR), and coefficient factor decreased significantly during fasting. Re-feeding accelerated growth and restored final body weight in groups previously fasted. Plasma insulin and glucose decreased in fasting, while normal levels were restored in all re-fed groups. The expression profile of insulin-like growth factors (IGFs) in liver and of the main muscle growth regulators in white muscle was examined using real-time quantitative RT-PCR. Fasting decreased the expression of IGF-I mRNA in both tissues, while re-feeding restored expression to control values. In contrast, IGF-II expression was not affected by any treatment in either tissue. Insulin- and IGF-I-binding assays in partial semi-purifications (of soluble proteins) in white skeletal muscle showed that insulin binding was not affected by either fasting or re-feeding, whereas fasting up-regulated IGF-I binding. The expression of IGFRIb mRNA in white skeletal muscle also increased with fasting, while IGFRIa increased with re-feeding, indicating that the two receptor isoforms are differentially regulated. The mRNA expression of myogenic regulator factors and fibroblast growth factors (FGFs) was not affected throughout the experiment, except for myogenin, which first decreased and then showed a rebound effect after 4 weeks of fasting. Myostatin mRNA expression did not change during fasting, although re-feeding caused a significant decrease. In conclusion, re-feeding of previously fasted trout induced compensatory growth. The differential regulation in muscle expression of IGF-I, IGF-I receptors, and myostatin indicates their contribution to this compensatory mechanism.
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Affiliation(s)
- N Montserrat
- Departament de Fisiologia, Facultat de Biologia, Universitat de Barcelona, E-08028 Barcelona, Spain.
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40
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Mendez P, Wandosell F, Garcia-Segura LM. Cross-talk between estrogen receptors and insulin-like growth factor-I receptor in the brain: cellular and molecular mechanisms. Front Neuroendocrinol 2006; 27:391-403. [PMID: 17049974 DOI: 10.1016/j.yfrne.2006.09.001] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2006] [Revised: 08/11/2006] [Accepted: 09/01/2006] [Indexed: 01/02/2023]
Abstract
Accumulating evidence suggests that insulin-like growth factor-I (IGF-I) and estradiol interact to regulate neural function. In this review, we focus on the cellular and molecular mechanisms involved in this interaction. The expression of estrogen receptors (ERs) and IGF-I receptor is cross-regulated in the central nervous system and many neurons and astrocytes coexpress both receptors. Furthermore, estradiol activates IGF-I receptor and its intracellular signaling. This effect may involve classical ERs since recent findings suggest that ERalpha may affect IGF-I actions in the brain by a direct interaction with some of the components of IGF-I signaling. In turn, IGF-I may regulate ER transcriptional activity in neuronal cells. In conclusion, ERs appear to be part of the signaling mechanism of IGF-I, and IGF-I receptor part of the mechanism of estradiol signaling in the nervous system.
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Affiliation(s)
- Pablo Mendez
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), E-28002 Madrid, Spain
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41
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Lin Y, Yang Q, Wang X, Liu ZG. The Essential Role of the Death Domain Kinase Receptor-interacting Protein in Insulin Growth Factor-I-induced c-Jun N-terminal Kinase Activation. J Biol Chem 2006; 281:23525-32. [PMID: 16793775 DOI: 10.1074/jbc.m601487200] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Insulin-like growth factor I (IGF-I) plays an important role in cell survival, proliferation, and differentiation. Diverse kinases, including AKT/protein kinase B, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK), can be activated by IGF-I. Here, we show that the receptor-interacting protein (RIP), a key mediator of tumor necrosis factor-induced NF-kappaB and JNK activation, plays a key role in IGF-I receptor signaling. IGF-I induced a robust JNK activation in wild type but not RIP null (RIP-/-) mouse embryonic fibroblast cells. Reconstitution of RIP expression in the RIP-/- cells restored the induction of JNK by IGF-I, suggesting that RIP is essential in IGF-I-induced JNK activation. Reconstitution experiments with different RIP mutants further revealed that the death domain and the kinase activity of RIP are not required for IGF-I-induced JNK activation. Interestingly, the AKT and ERK activation by IGF-I was normal in RIP-/- cells. The phosphatidylinositol 3-kinase inhibitor, wortmannin, did not affect IGF-I-induced JNK activation. These results agree with previous studies showing that the IGF-I-induced JNK activation pathway is distinct from that of ERK and AKT activation. Additionally, physical interaction of ectopically expressed RIP and IGF-IRbeta was detected by co-immunoprecipitation assays. More importantly, RIP was recruited to the IGF-I receptor complex during IGF-I-induced signaling. Furthermore, we found that IGF-I-induced cell proliferation was impaired in RIP-/- cells. Taken together, our results indicate that RIP, a key factor in tumor necrosis factor signaling, also plays a pivotal role in IGF-I-induced JNK activation and cell proliferation.
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Affiliation(s)
- Yong Lin
- Molecular Biology and Lung Cancer Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108, USA.
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42
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Phornphutkul C, Wu KY, Gruppuso PA. The role of insulin in chondrogenesis. Mol Cell Endocrinol 2006; 249:107-15. [PMID: 16530934 DOI: 10.1016/j.mce.2006.02.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2005] [Revised: 12/21/2005] [Accepted: 02/06/2006] [Indexed: 11/19/2022]
Abstract
The ATDC5 chondrogenic cell line is typically induced to differentiate by exposure to insulin at high concentration (10 microg/ml, approximately 1600 nM). Differentiation can also be induced by physiological concentrations of insulin-like growth factor-I (IGF-I). Unlike previous reports, we observed a stimulation of differentiation, as measured by collagen X expression and Alcian Blue staining for proteoglycan synthesis, upon exposure to insulin at concentrations (10-50 nM) consistent with signaling via the insulin receptor. Analysis of lysates from proliferating and hypertrophic ATDC5 cells demonstrated that exposure to 50 nM insulin induced tyrosine phosphorylation of insulin receptors but not IGF-I receptors or hybrid receptors. In contrast to the potent effects of IGF-I to stimulate both ATDC5 proliferation and differentiation, insulin was not as potent as IGF-I as a proliferating agent but more selectively a differentiating agent. Consistent with this result, insulin was less potent than IGF-I in inducing activation of the Erk1/Erk2 mitogenic signaling pathway. Furthermore, Erk pathway inhibition did not enhance the differentiating effects of insulin as it does in the case of IGF-I exposure. Extending our observations to fetal rat metatarsal explants, we observed significant stimulation of bone growth by 50 nM insulin. This could be accounted for by a disproportionate stimulatory effect on growth of the hypertrophic zone. The proliferative zone was not significantly affected. Based on our results in both ATDC5 cells and metatarsal explants, we conclude that the insulin functioning through insulin receptor has a dominant effect as an inducer of chondrocyte differentiation. These results support assignment of a physiological role for this hormone in linear bone growth.
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Affiliation(s)
- Chanika Phornphutkul
- Division of Pediatric Endocrinology and Metabolism, Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903, USA.
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43
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Guillen C, Navarro P, Robledo M, Valverde AM, Benito M. Differential mitogenic signaling in insulin receptor-deficient fetal pancreatic beta-cells. Endocrinology 2006; 147:1959-68. [PMID: 16396989 DOI: 10.1210/en.2005-0831] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Insulin receptor (IR) may play an essential role in the development of beta-cell mass in the mouse pancreas. To further define the function of this signaling system in beta-cell development, we generated IR-deficient beta-cell lines. Fetal pancreata were dissected from mice harboring a floxed allele of the insulin receptor (IRLoxP) and used to isolate islets. These islets were infected with a retrovirus to express simian virus 40 large T antigen, a strategy for establishing beta-cell lines (beta-IRLoxP). Subsequently, these cells were infected with adenovirus encoding cre recombinase to delete insulin receptor (beta-IR(-/-)). beta-Cells expressed insulin and Pdx-1 mRNA in response to glucose. In beta-IRLoxP beta-cells, p44/p42 MAPK and phosphatidylinositol 3 kinase pathways, mammalian target of rapamycin (mTOR), and p70S(6)K phosphorylation and beta-cell proliferation were stimulated in response to insulin. Wortmannin or PD98059 had no effect on insulin-mediated mTOR/p70S(6)K signaling and the corresponding mitogenic response. However, the presence of both inhibitors totally impaired these signaling pathways and mitogenesis in response to insulin. Rapamycin completely blocked insulin-activated mTOR/p70S(6)K signaling and mitogenesis. Interestingly, in beta-IR(-/-) beta-cells, glucose failed to stimulate phosphatidylinositol 3 kinase activity but induced p44/p42 MAPKs and mTOR/p70S(6)K phosphorylation and beta-cell mitogenesis. PD98059, but not wortmannin, inhibited glucose-induced mTOR/p70S(6)K signaling and mitogenesis in those cells. Finally, rapamycin blocked glucose-mediated mitogenesis of beta-IR(-/-) cells. In conclusion, independently of glucose, insulin can mediate mitogenesis in fetal pancreatic beta-cell lines. However, in the absence of the insulin receptor, glucose induces beta-cell mitogenesis.
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Affiliation(s)
- C Guillen
- Institute of Biochemistry/Department of Biochemistry and Molecular Biology, Joint Center Consejo Superior Investigacion Cientifica/Universidad Complutense, School of Pharmacy, Complutense University, Madrid, Spain
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Garcia-Segura LM, Sanz A, Mendez P. Cross-talk between IGF-I and estradiol in the brain: focus on neuroprotection. Neuroendocrinology 2006; 84:275-9. [PMID: 17124377 DOI: 10.1159/000097485] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2006] [Accepted: 10/17/2006] [Indexed: 12/27/2022]
Abstract
The actions of estradiol in the brain involve the interaction with growth factors, such as insulin-like growth factor-I (IGF-I). Many cells in the brain coexpress receptors for estradiol (ERs) and IGF-I (IGF-IR) and both factors interact to regulate neural function. Several studies have shown that there is an interaction of IGF-IR and ERs in neuroprotection. Neuroprotective effects of estradiol are blocked by the inhibition of IGF-IR signaling, while the neuroprotective effects of IGF-I are blocked by the inhibition of ER signaling. These findings suggest that the neuroprotective actions of estradiol and IGF-I after brain injury depend on the coactivation of both ERs and IGF-IR in neural cells. The relationship of ERalpha with IGF-IR through the phosphatidylinositol 3-kinase/Akt/glycogen synthase kinase 3beta (PI3K/Akt/GSK3) signaling pathway may represent the point of convergence used by estradiol and IGF-I to cooperatively promote neuroprotection. Administration of estradiol to ovariectomized rats results in the association of ERalpha with IGF-IR and with components of the PI3K/Akt/GSK3 signaling pathway and in the regulation of the activity of Akt and GSK3 in the brain. Conversely, IGF-I regulates ERalpha transcriptional activity in neuroblastoma cells and the PI3K/Akt/GSK3 signaling pathway is involved in this effect.
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Affiliation(s)
- Luis M Garcia-Segura
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.
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Hao Z, Li X, Qiao T, Zhang J, Shao X, Fan D. Distribution of CIAPIN1 in normal fetal and adult human tissues. J Histochem Cytochem 2005; 54:417-26. [PMID: 16314443 DOI: 10.1369/jhc.5a6753.2005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
CIAPIN1, a newly identified antiapoptotic molecule that plays an essential role in mouse definitive hematopoiesis, is considered a downstream effector of the receptor tyrosine kinase-Ras signaling pathway. Our previous studies have indicated that CIAPIN1 is involved in the development of multidrug resistance (MDR) in gastric cancer cells. However, the mechanism of CIAPIN1-mediated antiapoptosis and MDR has not been fully elucidated. To reveal the possible physiological role of CIAPIN1, we examined the expression and distribution of CIAPIN1 in fetal and adult human tissues using immunohistochemistry. We found that CIAPIN1 was ubiquitously distributed in fetal and adult tissues, and was localized in both the cytoplasm and the nucleus. The expression patterns of CIAPIN1 were similar in fetal and adult tissues, and was correlated with the previously described expression pattern of p21ras. These observations suggest that CIAPIN1 expression appears to be involved in cell differentiation, and that it might exert universal and possibly important physiological functions under the regulation of Ras in humans.
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Affiliation(s)
- Zhiming Hao
- State Key Laboratory of Cancer Biology, Institute of Digestive Diseases, Xijing Hospital, The Fourth Military Medical University, Xi'an, 710032 Shaanxi Province, China
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Cariello NF, Romach EH, Colton HM, Ni H, Yoon L, Falls JG, Casey W, Creech D, Anderson SP, Benavides GR, Hoivik DJ, Brown R, Miller RT. Gene expression profiling of the PPAR-alpha agonist ciprofibrate in the cynomolgus monkey liver. Toxicol Sci 2005; 88:250-64. [PMID: 16081524 DOI: 10.1093/toxsci/kfi273] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Fibrates, such as ciprofibrate, fenofibrate, and clofibrate, are peroxisome proliferator-activated receptor-alpha (PPARalpha) agonists that have been in clinical use for many decades for treatment of dyslipidemia. When mice and rats are given PPARalpha agonists, these drugs cause hepatic peroxisome proliferation, hypertrophy, hyperplasia, and eventually hepatocarcinogenesis. Importantly, primates are relatively refractory to these effects; however, the mechanisms for the species differences are not clearly understood. Cynomolgus monkeys were exposed to ciprofibrate at various dose levels for either 4 or 15 days, and the liver transcriptional profiles were examined using Affymetrix human GeneChips. Strong upregulation of many genes relating to fatty acid metabolism and mitochondrial oxidative phosphorylation was observed; this reflects the known pharmacology and activity of the fibrates. In addition, (1) many genes related to ribosome and proteasome biosynthesis were upregulated, (2) a large number of genes downregulated were in the complement and coagulation cascades, (3) a number of key regulatory genes, including members of the JUN, MYC, and NFkappaB families were downregulated, which appears to be in contrast to the rodent, where JUN and MYC are reported to upregulated after PPARalpha agonist treatment, (4) no transcriptional signal for DNA damage or oxidative stress was observed, and (5) transcriptional signals consistent with an anti-proliferative and a pro-apoptotic effect were seen. We also compared the primate data to literature reports of hepatic transcriptional profiling in PPARalpha-treated rodents, which showed that the magnitude of induction in beta-oxidation pathways was substantially greater in the rodent than the primate.
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Affiliation(s)
- Neal F Cariello
- GlaxoSmithKline Inc., Safety Assessment, Research Triangle Park, North Carolina 27709, USA.
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Grant PA, Kind KL, Roberts CT, Sohlstrom A, Owens PC, Owens JA. Late pregnancy increases hepatic expression of insulin-like growth factor-I in well nourished guinea pigs. Growth Horm IGF Res 2005; 15:165-171. [PMID: 15809021 DOI: 10.1016/j.ghir.2005.01.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Blood IGF-I concentrations are persistently elevated throughout pregnancy in humans and guinea pigs and may regulate substrate partitioning between mother and conceptus. In the guinea pig, liver and adipose tissue have recently been suggested to contribute to the increased levels of circulating IGF-I in mid-pregnancy, but whether this persists in late pregnancy in undernutrition is not known. Therefore the effect of pregnancy and undernutrition on circulating IGF-I and hepatic expression of IGF-I in late gestation in the guinea pig was examined. Female guinea pigs (Cavia porcellus) were fed ad libitum throughout pregnancy or 70% of ad libitum intake for 28 days prior to and throughout pregnancy (term is 69 d). Non-pregnant animals were maintained for 88 days on the same diets. Plasma IGF-I was measured by RIA after molecular sieving chromatography at low pH. Abundances of IGF-I and beta-actin mRNA in maternal liver were quantified by digoxigenin-ELISA after RT PCR. Late pregnancy increased both the concentration of IGF-I protein (p<0.001) in plasma and the relative abundance of liver IGF-I mRNA (p<0.001) in ad libitum fed, but not in feed restricted pregnant guinea pigs. The concentration of IGF-I protein in plasma correlated positively with the relative abundance of IGF-I mRNA in liver overall (p<0.002), suggesting the liver as a major source of endocrine IGF-I in late pregnant guinea pigs. This study demonstrates that hepatic expression of IGF-I remains elevated during late pregnancy in the well fed guinea pig, which is in contrast to that observed in other non-human species.
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Affiliation(s)
- P A Grant
- Department of Obstetrics and Gynaecology, University of Adelaide, Adelaide 5005, Australia.
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Schweiger M, Steffl M, Amselgruber WM. Cell-type specific expression of IGF-1R in porcine islet cells. Growth Horm IGF Res 2005; 15:33-38. [PMID: 15701570 DOI: 10.1016/j.ghir.2004.11.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2004] [Revised: 11/12/2004] [Accepted: 11/15/2004] [Indexed: 11/21/2022]
Abstract
Insulin-like growth factor-1 (IGF-1) functions as a growth factor regarding physiological regulations of cellular metabolism, regeneration and growth. In pancreas islets their potential function is unclear and only little information is available on occurrence and distribution of the corresponding insulin-like growth factor-1 receptor (IGF-1R) in islet cells. Therefore, we investigated the localization of IGF-1R by immunohistochemical techniques and its possible co-localization with other islet hormones. Further, we applied molecular biology techniques to determine the present of local gene expression of IGF-1R and IGF-1. Immunostaining on serial sections with anti-insulin, anti-glucagon and anti-somatostatin antibodies shows, IGF-1R was selectively expressed in insulin-producing B-cells and additionally more pronounced in somatostatin-containing D-cells, which are located in the periphery of porcine pancreatic islets. Furthermore, the RT-PCR experiment demonstrates clearly that IGF-1 and IGF-1R was expressed together in the porcine pancreas. The high expression of IGF-1R in porcine D-cells indicates that mammalian IGF-1R genes are regulated in a different manner since it was shown that in all other species IGF-1R was expressed in B- and A-cells but not in D-cells.
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Affiliation(s)
- Markus Schweiger
- Institute of Anatomy and Physiology, University of Hohenheim, Fruwirthstrasse 35, Stuttgart 70593, Germany
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Valverde AM, Mur C, Brownlee M, Benito M. Susceptibility to apoptosis in insulin-like growth factor-I receptor-deficient brown adipocytes. Mol Biol Cell 2004; 15:5101-17. [PMID: 15356271 PMCID: PMC524782 DOI: 10.1091/mbc.e03-11-0853] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Fetal brown adipocytes are insulin-like growth factor-I (IGF-I) target cells. To assess the importance of the IGF-I receptor (IGF-IR) in brown adipocytes during fetal life, we have generated immortalized brown adipocyte cell lines from the IGF-IR(-/-) mice. Using this experimental model, we demonstrate that the lack of IGF-IR in fetal brown adipocytes increased the susceptibility to apoptosis induced by serum withdrawal. Culture of cells in the absence of serum and growth factors produced rapid DNA fragmentation (4 h) in IGF-IR(-/-) brown adipocytes, compared with the wild type (16 h). Consequently, cell viability was decreased more rapidly in fetal brown adipocytes in the absence of IGF-IR. Furthermore, caspase-3 activity was induced much earlier in cells lacking IGF-IR. At the molecular level, IGF-IR deficiency in fetal brown adipocytes altered the balance of the expression of several proapoptotic (Bcl-xS and Bim) and antiapoptotic (Bcl-2 and Bcl-xL) members of the Bcl-2 family. This imbalance was irreversible even though in IGF-IR-reconstituted cells. Likewise, cytosolic cytochrome c levels increased rapidly in IGF-IR-deficient cells compared with the wild type. A rapid entry of Foxo1 into the nucleus accompanied by a rapid exit from the cytosol and an earlier activation of caspase-8 were observed in brown adipocytes lacking IGF-IR upon serum deprivation. Activation of caspase-8 was inhibited by 50% in both cell types by neutralizing anti-Fas-ligand antibody. Adenoviral infection of wild-type brown adipocytes with constitutively active Foxol (ADA) increased the expression of antiapoptotic genes, decreased Bcl-xL and induced caspase-8 and -3 activities, with the final outcome of DNA fragmentation. Up-regulation of uncoupling protein-1 (UCP-1) expression in IGF-IR-deficient cells by transduction with PGC-1alpha or UCP-1 ameliorated caspase-3 activation, thereby retarding apoptosis. Finally, insulin treatment prevented apoptosis in both cell types. However, the survival effect of insulin on IGF-IR(-/-) brown adipocytes was elicited even in the absence of phosphatidylinositol 3-kinase/Akt signaling. Thus, our results demonstrate for the first time the unique role of IGF-IR in maintaining the balance of death and survival in fetal brown adipocytes.
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Affiliation(s)
- Angela M Valverde
- Departamento de Bioquímica y Biología Molecular II, Centro Mixto Consejo Superior de Investigaciones Cientificas, Universidad Complutense de Madrid, Facultad de Farmacia, Ciudad Universitaria, 28040-Madrid, Spain.
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Shimoaka T, Kamekura S, Chikuda H, Hoshi K, Chung UI, Akune T, Maruyama Z, Komori T, Matsumoto M, Ogawa W, Terauchi Y, Kadowaki T, Nakamura K, Kawaguchi H. Impairment of Bone Healing by Insulin Receptor Substrate-1 Deficiency. J Biol Chem 2004; 279:15314-22. [PMID: 14736890 DOI: 10.1074/jbc.m312525200] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Insulin receptor substrate-1 (IRS-1) is an essential molecule for intracellular signaling of insulin-like growth factor (IGF)-I and insulin, both of which are potent anabolic regulators of bone and cartilage metabolism. To investigate the role of IRS-1 in bone regeneration, fracture was introduced in the tibia, and its healing was compared between wild-type (WT) mice and mice lacking the IRS-1 gene (IRS-1(-/-) mice). Among 15 IRS-1(-/-) mice, 12 remained in a non-union state even at 10 weeks after the operation, whereas all 15 WT mice showed a rigid bone union at 3 weeks. This impairment was because of the suppression of callus formation with a decrease in chondrocyte proliferation and increases in hypertrophic differentiation and apoptosis. Reintroduction of IRS-1 to the IRS-1(-/-) fractured site using an adenovirus vector significantly restored the callus formation. In the culture of chondrocytes isolated from the mouse growth plate, IRS-1(-/-) chondrocytes showed less mitogenic ability and Akt phosphorylation than WT chondrocytes. An Akt inhibitor decreased the IGF-I-stimulated DNA synthesis of chondrocytes more potently in the WT culture than in the IRS-1(-/-) culture. We therefore conclude that IRS-1 deficiency impairs bone healing at least partly by inhibiting chondrocyte proliferation through the phosphatidylinositol 3-kinase/Akt pathway, and we propose that IRS-1 can be a target molecule for bone regenerative medicine.
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Affiliation(s)
- Takashi Shimoaka
- Departments of Orthopaedic Surgery, Tissue Engineering, and Metabolic Diseases, Faculty of Medicine, University of Tokyo, Hongo, Bunkyo, Tokyo 113-8655, Japan
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