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1
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Adzavon KP, Zhao W, Khattak SN, Sheng W. Cholesterol-modified peptide nanomicelles as a promising platform for cancer therapy: A review. Int J Biol Macromol 2025; 311:143456. [PMID: 40274168 DOI: 10.1016/j.ijbiomac.2025.143456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2025] [Revised: 04/01/2025] [Accepted: 04/22/2025] [Indexed: 04/26/2025]
Abstract
Drug resistance, systemic toxicity, low solubility, and rapid clearance are common issues with chemotherapy drugs and other molecules used to treat cancer. The development of new therapeutic compounds and nanotherapy offers a solution to these issues. Therapeutic peptides have attracted great interest among these molecules due to their unique advantages, including low immunogenicity, efficient cellular internalization, deep tissue penetration, and low systemic toxicity. They have shown promise in cancer treatment by inducing apoptosis, necrosis, or cell lysis and promoting immunotherapy. In addition, peptides can deliver a range of cargoes, such as drugs, nucleic acids, imaging agents, and nanoparticles, and can specifically target cancer cells. However, problems such as their short half-life and low solubility limit their therapeutic use. Recent developments have addressed these constraints through structural alterations and nanoparticle formulations. In particular, cholesterol modification makes it possible for peptides to self-assemble into nanomicelles, which enhances their stability, half-life, and cell penetration. In this review, therapeutic peptides are presented as a versatile and successful cancer treatment option. The potential of cholesterol-modified peptide micelles as a reliable drug, nucleic acid, and imaging agent delivery system is also examined.
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Affiliation(s)
- Kodzo Prosper Adzavon
- College of Chemistry and Life Science, Beijing University of Technology, Beijing 100124, China
| | - Weijian Zhao
- College of Chemistry and Life Science, Beijing University of Technology, Beijing 100124, China
| | - Sameena Noor Khattak
- College of Chemistry and Life Science, Beijing University of Technology, Beijing 100124, China
| | - Wang Sheng
- College of Chemistry and Life Science, Beijing University of Technology, Beijing 100124, China.
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2
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Iwaï H, Beyer HM, Johansson JEM, Li M, Wlodawer A. The three-dimensional structure of the Vint domain from Tetrahymena thermophila suggests a ligand-regulated cleavage mechanism by the HINT fold. FEBS Lett 2024; 598:864-874. [PMID: 38351630 DOI: 10.1002/1873-3468.14817] [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: 11/12/2023] [Revised: 12/13/2023] [Accepted: 01/03/2024] [Indexed: 04/23/2024]
Abstract
Vint proteins have been identified in unicellular metazoans as a novel hedgehog-related gene family, merging the von Willebrand factor type A domain and the Hedgehog/INTein (HINT) domains. We present the first three-dimensional structure of the Vint domain from Tetrahymena thermophila corresponding to the auto-processing domain of hedgehog proteins, shedding light on the unique features, including an adduct recognition region (ARR). Our results suggest a potential binding between the ARR and sulfated glycosaminoglycans like heparin sulfate. Moreover, we uncover a possible regulatory role of the ARR in the auto-processing by Vint domains, expanding our understanding of the HINT domain evolution and their use in biotechnological applications. Vint domains might have played a crucial role in the transition from unicellular to multicellular organisms.
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Affiliation(s)
- Hideo Iwaï
- Institute of Biotechnology, University of Helsinki, Finland
| | - Hannes M Beyer
- Institute of Biotechnology, University of Helsinki, Finland
| | | | - Mi Li
- Center for Structural Biology, National Cancer Institute, Frederick, MD, USA
- Basic Science Program, Frederick National Laboratory for Cancer Research, MD, USA
| | - Alexander Wlodawer
- Center for Structural Biology, National Cancer Institute, Frederick, MD, USA
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3
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Tharappel AM, Li Z, Zhu YC, Wu X, Chaturvedi S, Zhang QY, Li H. Calcimycin Inhibits Cryptococcus neoformans In Vitro and In Vivo by Targeting the Prp8 Intein Splicing. ACS Infect Dis 2022; 8:1851-1868. [PMID: 35948057 PMCID: PMC9464717 DOI: 10.1021/acsinfecdis.2c00137] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Drug resistance is a significant concern in the treatment of diseases, including cryptococcosis caused by Cryptococcus neoformans (Cne) and Cryptococcus gattii (Cga). Alternative drug targets are necessary to overcome drug resistance before it attains a critical stage. Splicing of inteins from pro-protein precursors is crucial for activities of essential proteins hosting intein elements in many organisms, including human pathogens such as Cne and Cga. Through a high-throughput screening, we identified calcimycin (CMN) as a potent Prp8 intein splicing inhibitor with a minimum inhibitory concentration (MIC) of 1.5 μg/mL against the wild-type Cne-H99 (Cne-WT or Cne). In contrast, CMN inhibited the intein-less mutant strain (Cne-Mut) with a 16-fold higher MIC. Interestingly, Aspergillus fumigatus and a few Candida species were resistant to CMN. Further studies indicated that CMN reduced virulence factors such as urease activity, melanin production, and biofilm formation in Cne. CMN also inhibited Cne intracellular infection in macrophages. In a target-specific split nanoluciferase assay, the IC50 of CMN was 4.6 μg/mL. Binding of CMN to recombinant Prp8 intein was demonstrated by thermal shift assay and microscale thermophoresis. Treating Cne cells with CMN reduced intein splicing. CMN was fungistatic and showed a synergistic effect with the known antifungal drug amphotericin B. Finally, CMN treatment at 20 mg/kg body weight led to 60% reduction in lung fungal load in a cryptococcal pulmonary infection mouse model. Overall, CMN represents a potent antifungal with a novel mechanism of action to treat Cne and possibly Cga infections.
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Affiliation(s)
- Anil Mathew Tharappel
- Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson Arizona 85721-0207, United States
- Wadsworth Center, New York State Department of Health, Albany, New York 12208, United States
| | - Zhong Li
- Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson Arizona 85721-0207, United States
- Wadsworth Center, New York State Department of Health, Albany, New York 12208, United States
| | - Yan Chun Zhu
- Wadsworth Center, New York State Department of Health, Albany, New York 12208, United States
| | - Xiangmeng Wu
- Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson Arizona 85721-0207, United States
| | - Sudha Chaturvedi
- Wadsworth Center, New York State Department of Health, Albany, New York 12208, United States
| | - Qing-Yu Zhang
- Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson Arizona 85721-0207, United States
| | - Hongmin Li
- Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson Arizona 85721-0207, United States
- Wadsworth Center, New York State Department of Health, Albany, New York 12208, United States
- The BIO5 Institute, The University of Arizona, Tucson, Arizona 85721, United States
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4
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Kaushal JB, Batra SK, Rachagani S. Hedgehog signaling and its molecular perspective with cholesterol: a comprehensive review. Cell Mol Life Sci 2022; 79:266. [PMID: 35486193 PMCID: PMC9990174 DOI: 10.1007/s00018-022-04233-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/18/2022] [Accepted: 03/07/2022] [Indexed: 02/08/2023]
Abstract
Hedgehog (Hh) signaling is evolutionarily conserved and plays an instructional role in embryonic morphogenesis, organogenesis in various animals, and the central nervous system organization. Multiple feedback mechanisms dynamically regulate this pathway in a spatiotemporal and context-dependent manner to confer differential patterns in cell fate determination. Hh signaling is complex due to canonical and non-canonical mechanisms coordinating cell-cell communication. In addition, studies have demonstrated a regulatory framework of Hh signaling and shown that cholesterol is vital for Hh ligand biogenesis, signal generation, and transduction from the cell surface to intracellular space. Studies have shown the importance of a specific cholesterol pool, termed accessible cholesterol, which serves as a second messenger, conveying signals between smoothened (Smo) and patched 1 (Ptch1) across the plasma and ciliary membranes. Remarkably, recent high-resolution structural and molecular studies shed new light on the interplay between Hh signaling and cholesterol in membrane biology. These studies elucidated novel mechanistic insight into the release and dispersal of cholesterol-anchored Hh and the basis of Hh recognition by Ptch1. Additionally, the putative model of Smo activation by cholesterol binding and/or modification and Ptch1 antagonization of Smo has been explicated. However, the coupling mechanism of Hh signaling and cholesterol offered a new regulatory principle in cell biology: how effector molecules of the Hh signal network react to and remodel cholesterol accessibility in the membrane and selectively activate Hh signaling proteins thereof. Recognizing the biological importance of cholesterol in Hh signaling activation and transduction opens the door for translational research to develop novel therapeutic strategies. This review looks in-depth at canonical and non-canonical Hh signaling and the distinct proposed model of cholesterol-mediated regulation of Hh signaling components, facilitating a more sophisticated understanding of the Hh signal network and cholesterol biology.
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Affiliation(s)
- Jyoti B Kaushal
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Surinder K Batra
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
- Fred and Pamela Buffet Cancer Center, Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
| | - Satyanarayana Rachagani
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
- Fred and Pamela Buffet Cancer Center, Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
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5
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Huang P, Wierbowski BM, Lian T, Chan C, García-Linares S, Jiang J, Salic A. Structural basis for catalyzed assembly of the Sonic hedgehog-Patched1 signaling complex. Dev Cell 2022; 57:670-685.e8. [PMID: 35231446 PMCID: PMC8932645 DOI: 10.1016/j.devcel.2022.02.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 01/13/2022] [Accepted: 02/04/2022] [Indexed: 01/04/2023]
Abstract
The dually lipidated Sonic hedgehog (SHH) morphogen signals through the tumor suppressor membrane protein Patched1 (PTCH1) to activate the Hedgehog pathway, which is fundamental in development and cancer. SHH engagement with PTCH1 requires the GAS1 coreceptor, but the mechanism is unknown. We demonstrate a unique role for GAS1, catalyzing SHH-PTCH1 complex assembly in vertebrate cells by direct SHH transfer from the extracellular SCUBE2 carrier to PTCH1. Structure of the GAS1-SHH-PTCH1 transition state identifies how GAS1 recognizes the SHH palmitate and cholesterol modifications in modular fashion and how it facilitates lipid-dependent SHH handoff to PTCH1. Structure-guided experiments elucidate SHH movement from SCUBE2 to PTCH1, explain disease mutations, and demonstrate that SHH-induced PTCH1 dimerization causes its internalization from the cell surface. These results define how the signaling-competent SHH-PTCH1 complex assembles, the key step triggering the Hedgehog pathway, and provide a paradigm for understanding morphogen reception and its regulation.
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Affiliation(s)
- Pengxiang Huang
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Tengfei Lian
- Laboratory of Membrane Proteins and Structural Biology, Biochemistry and Biophysics Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Charlene Chan
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Jiansen Jiang
- Laboratory of Membrane Proteins and Structural Biology, Biochemistry and Biophysics Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Adrian Salic
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
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6
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Chen Q, Chen H, Wang M, Qiu L, Xi F, Jiang Y, Lv M, Huang HF, Luo Q. The association between alteration of maternal lipid levels and birthweight at term: A within-family comparison. Front Endocrinol (Lausanne) 2022; 13:989663. [PMID: 36246889 PMCID: PMC9562839 DOI: 10.3389/fendo.2022.989663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 09/16/2022] [Indexed: 11/29/2022] Open
Abstract
CONTEXT Maternal lipid levels affect birthweight and the long-term health of the offsprings. However, this association could be influenced by genetic and other common factors. OBJECTIVE This work aimed to explore the relationship between maternal lipid levels and birthweight of two pregnancies in the same mother. METHODS In this population-based cohort study, 705 women and their 1 410 offsprings were included. From an initial sample of women with more than one singleton birth in the database, we made the following exclusions: missing data for pre-pregnancy BMI, pregnancy weight gain, birthweight and lipid values; maternal age less than 19 or older than 44 years old; gestational age < 37 weeks or > 41weeks, gestational diabetes mellitus/diabetic. In the second and third trimesters, serum samples were collected for the determination of fasting total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) levels. Then we assessed the association between maternal lipids and birthweight. RESULTS Infants of women whose 2nd-trimester TC increased by 10th-20th percentile (-0.92~-0.56 mmol/L) from 1st to 2nd pregnancy were 239.69 (62.32~417.06) g lighter at birth than were infants of women those of 40th-50th percentile (-0.20~-0.03 mmol/L). Parity, gestational age, neonatal gender, maternal pre-pregnancy body mass index, maternal weight gain, and 3rd-trimester TC and HDL-C were all associated with higher birth weight. Every unit increase in TC in the third trimester increases birthweight by 53.13 (14.32 ~91.94) g. CONCLUSION Maternal TC level is associated with birthweight independent of shared genes. TC may be used to guide diet and predict birthweight combined with ultrasound and other indicators.
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Affiliation(s)
- Qinqing Chen
- Department of Obstetrics, Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Huiqi Chen
- School of Public Health, Sun Yat-sen University, Guangzhou, China
| | - Minmin Wang
- Department of Obstetrics, Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Liping Qiu
- Department of Obstetrics, Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Fangfang Xi
- Department of Obstetrics, Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Ying Jiang
- Department of Obstetrics, Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Min Lv
- Department of Obstetrics, Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - He-Feng Huang
- Department of Obstetrics, Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- *Correspondence: Qiong Luo, ; He-Feng Huang,
| | - Qiong Luo
- Department of Obstetrics, Women’s Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- *Correspondence: Qiong Luo, ; He-Feng Huang,
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7
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Gu Y, Liu X, Liao L, Gao Y, Shi Y, Ni J, He G. Relationship between lipid metabolism and Hedgehog signaling pathway. J Steroid Biochem Mol Biol 2021; 209:105825. [PMID: 33529733 DOI: 10.1016/j.jsbmb.2021.105825] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 10/28/2020] [Accepted: 01/13/2021] [Indexed: 02/08/2023]
Abstract
The Hedgehog (Hh) signaling pathway is highly conserved signaling pathway in cells. Steroids was found to play a vital role in Hh signaling pathway and aberrant Hh signaling was found to lead a series of disease correlate with abnormal lipid metabolism. This paper aimed to elucidate the relationship between lipid metabolism and Hedgehog signaling pathway.
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Affiliation(s)
- Yuan Gu
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Hunan 410011, PR China
| | - Xiaochen Liu
- University of Toledo Medical Center 3000 Arlington Ave. Toledo, OH 43614, USA
| | - Lele Liao
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Hunan 410011, PR China
| | - Yongquan Gao
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Hunan 410011, PR China
| | - Yu Shi
- West China School of Stomatology, Sichuan University, Chengdu 610041, PR China; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, PR China
| | - Jiangdong Ni
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Hunan 410011, PR China
| | - Guangxu He
- Department of Orthopedics, The Second Xiangya Hospital, Central South University, Hunan 410011, PR China.
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8
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Fliesler SJ. EDITOR'S PERSPECTIVE: On the verge of translation: Combined cholesterol-antioxidant supplementation as a potential therapeutic intervention for Smith-Lemli-Opitz syndrome. Exp Eye Res 2020; 202:108390. [PMID: 33307076 DOI: 10.1016/j.exer.2020.108390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Steven J Fliesler
- Departments of Ophthalmology and Biochemistry and the Neuroscience Graduate Program, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo- the State University of New York, Buffalo, NY, 14215-1129, USA; Research Service, Western New York Healthcare System, Buffalo, NY, 14215-1129, USA.
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9
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Wierbowski BM, Petrov K, Aravena L, Gu G, Xu Y, Salic A. Hedgehog Pathway Activation Requires Coreceptor-Catalyzed, Lipid-Dependent Relay of the Sonic Hedgehog Ligand. Dev Cell 2020; 55:450-467.e8. [PMID: 33038332 DOI: 10.1016/j.devcel.2020.09.017] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 08/04/2020] [Accepted: 09/14/2020] [Indexed: 12/25/2022]
Abstract
Hedgehog signaling governs critical processes in embryogenesis, adult stem cell maintenance, and tumorigenesis. The activating ligand, Sonic hedgehog (SHH), is highly hydrophobic because of dual palmitate and cholesterol modification, and thus, its release from cells requires the secreted SCUBE proteins. We demonstrate that the soluble SCUBE-SHH complex, although highly potent in cellular assays, cannot directly signal through the SHH receptor, Patched1 (PTCH1). Rather, signaling by SCUBE-SHH requires a molecular relay mediated by the coreceptors CDON/BOC and GAS1, which relieves SHH inhibition by SCUBE. CDON/BOC bind both SCUBE and SHH, recruiting the complex to the cell surface. SHH is then handed off, in a dual lipid-dependent manner, to GAS1, and from GAS1 to PTCH1, initiating signaling. These results define an essential step in Hedgehog signaling, whereby coreceptors activate SHH by chaperoning it from a latent extracellular complex to its cell-surface receptor, and point to a broader paradigm of coreceptor function.
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Affiliation(s)
| | - Kostadin Petrov
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Laura Aravena
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Garrick Gu
- Williams College, Williamstown, MA 01267, USA
| | - Yangqing Xu
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Adrian Salic
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
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10
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Shi X, Simms KJ, Zhang P. Acute Alcohol Intoxication Impairs Sonic Hedgehog-Gli1 Signaling and Activation of Primitive Hematopoietic Precursor Cells in the Early Stage of Host Response to Bacteremia. Alcohol Clin Exp Res 2020; 44:1977-1987. [PMID: 32772391 PMCID: PMC7720280 DOI: 10.1111/acer.14429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 07/29/2020] [Indexed: 11/29/2022]
Abstract
BACKGROUND Activation of hematopoietic stem cells [HSCs, lineage(lin)- stem cell growth factor receptor (c-kit)+ stem cell antigen-1(Sca-1)+ , or LKS cells in mice] is critical for initiating the granulopoietic response. This study determined the effect of alcohol exposure on sonic hedgehog (SHH) signaling in the regulation of HSC activation during bacteremia. METHODS Acute alcohol intoxication was induced in mice by intraperitoneal (i.p.) injection of 20% alcohol (5 g alcohol/kg body weight). Control mice received i.p. saline. Thirty minutes later, mice were intravenously (i.v.) injected with Escherichia coli (E. coli, 1 to 5 × 107 CFUs/mouse) or saline. RESULTS SHH expression by lineage-negative bone marrow cells (BMCs) was significantly increased 24 hours after E. coli infection. Extracellular signal-regulated kinase 1/2 (ERK1/2)-specificity protein 1 (Sp1) signaling promotes SHH expression. ERK1/2 was markedly activated in BMCs 8 hours following E. coli infection. Alcohol suppressed both the activation of ERK1/2 and up-regulation of SHH expression following E. coli infection. E. coli infection up-regulated GLI family zinc finger 1 (Gli1) gene expression by BMCs and increased Gli1 protein content in LKS cells. The extent of Gli1 expression was correlated with the activity of proliferation in LKS cells. Alcohol inhibited up-regulation of Gli1 expression and activation of LKS cells in response to E. coli infection. Alcohol also interrupted the granulopoietic response to bacteremia. CONCLUSION These data show that alcohol disrupts SHH-Gli1 signaling and HSC activation in the early stage of the granulopoietic response, which may serve as an important mechanism underlying the impairment of immune defense against bacterial infection in host excessively consuming alcohol.
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Affiliation(s)
- Xin Shi
- From the Department of Integrative Medical Sciences, College of Medicine, Northeast Ohio Medical University, Rootstown, Ohio
| | - Kevin J Simms
- From the Department of Integrative Medical Sciences, College of Medicine, Northeast Ohio Medical University, Rootstown, Ohio
| | - Ping Zhang
- From the Department of Integrative Medical Sciences, College of Medicine, Northeast Ohio Medical University, Rootstown, Ohio
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11
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Dual roles of the sterol recognition region in Hedgehog protein modification. Commun Biol 2020; 3:250. [PMID: 32440000 PMCID: PMC7242414 DOI: 10.1038/s42003-020-0977-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 04/28/2020] [Indexed: 11/08/2022] Open
Abstract
Nature provides a number of mechanisms to encode dynamic information in biomolecules. In metazoans, there exist rare chemical modifications that occur in entirely unique regimes. One such example occurs in the Hedgehog (Hh) morphogens, proteins singular across all domains of life for the nature of their covalent ligation to cholesterol. The isoform- and context-specific efficiency of this ligation profoundly impacts the activity of Hh morphogens and represents an unexplored facet of Hh ligand-dependent cancers. To elucidate the chemical mechanism of this modification, we have defined roles of the uncharacterized sterol recognition region (SRR) in Hh proteins. We use a combination of sequence conservation, directed mutagenesis, and biochemical assays to specify residues of the SRR participate in cellular and biochemical aspects of Hh cholesterolysis. Our investigations offer a functional portrait of this region, providing opportunities to identify parallel reactivity in nature and a template to design tools in chemical biology.
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12
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Kramer B, Molema K, Hutchinson EF. An osteological assessment of cyclopia by micro-CT scanning. Surg Radiol Anat 2019; 41:1053-1063. [PMID: 31300839 DOI: 10.1007/s00276-019-02284-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 07/01/2019] [Indexed: 10/26/2022]
Abstract
PURPOSE Imaging modalities such as micro-CT scanning and three-dimensional reconstruction are providing a mechanism for detailed analysis of skeletal components not only of normal specimens but also through revisitation of the abnormal. The aim of this study was to analyse the craniofacial skeleton of five human fetuses with cyclopia by means of micro-CT scanning and three-dimensional reconstruction. MATERIALS AND METHODS The study consisted of five cyclopean individuals from the paediatric collection of the School of Anatomical Sciences, University of the Witwatersrand. The specimens ranged in age from 22 to 42 weeks of gestation. The osteological features of each bone of the skull were analysed with the aid of micro-CT scanning and analysis using VG studiomax software. RESULTS A detailed analysis of all the bones of the skull revealed that the upper two-thirds of the viscerocranium and the anterior region of the basicranium were the most affected regions of the cyclopean fetuses. The ethmoid, nasal, inferior concha and the lacrimal bones were absent in all the cases of cyclopia. Major abnormalities were found in the premaxillary region which affected the development of the anterior dentition. CONCLUSION This study supports the suggestion that the malformations of the visceral bones are secondary to defective development of the presphenoid and mesethmoid cartilages. The ethmoidal bones are important midline struts during normal development and their absence in cyclopia leads to non-laterality of facial features.
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Affiliation(s)
- Beverley Kramer
- School of Anatomical Sciences, Medical School, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
| | - Kgalaletso Molema
- School of Anatomical Sciences, Medical School, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Erin F Hutchinson
- School of Anatomical Sciences, Medical School, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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13
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Kamino D, Chau V, Studholme C, Liu M, Xu D, James Barkovich A, Ferriero DM, Miller SP, Brant R, Tam EW. Plasma cholesterol levels and brain development in preterm newborns. Pediatr Res 2019; 85:299-304. [PMID: 30635642 PMCID: PMC6433157 DOI: 10.1038/s41390-018-0260-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 11/30/2018] [Indexed: 11/30/2022]
Abstract
BACKGROUND To assess whether postnatal plasma cholesterol levels are associated with microstructural and macrostructural regional brain development in preterm newborns. METHODS Sixty preterm newborns (born 24-32 weeks gestational age) were assessed using MRI studies soon after birth and again at term-equivalent age. Blood samples were obtained within 7 days of each MRI scan to analyze for plasma cholesterol and lathosterol (a marker of endogenous cholesterol synthesis) levels. Outcomes were assessed at 3 years using the Bayley Scales of Infant Development, Third Edition. RESULTS Early plasma lathosterol levels were associated with increased axial and radial diffusivities and increased volume of the subcortical white matter. Early plasma cholesterol levels were associated with increased volume of the cerebellum. Early plasma lathosterol levels were associated with a 2-point decrease in motor scores at 3 years. CONCLUSIONS Higher early endogenous cholesterol synthesis is associated with worse microstructural measures and larger volumes in the subcortical white matter that may signify regional edema and worse motor outcomes. Higher early cholesterol is associated with improved cerebellar volumes. Further work is needed to better understand how the balance of cholesterol supply and endogenous synthesis impacts preterm brain development, especially if these may be modifiable factors to improve outcomes.
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Affiliation(s)
- Daphne Kamino
- Department of Paediatrics, Division of Neurology Hospital for Sick Children, Toronto, Ontario, Canada
| | - Vann Chau
- Department of Paediatrics, Division of Neurology Hospital for Sick Children, Toronto, Ontario, Canada
| | - Colin Studholme
- Department of Pediatrics and Department of Bioengineering and Radiology, University of Washington, Seattle, WA
| | - Mengyuan Liu
- Department of Pediatrics and Department of Bioengineering and Radiology, University of Washington, Seattle, WA
| | - Duan Xu
- Departments of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
| | - A. James Barkovich
- Departments of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA,Departments of Pediatrics and Neurology, University of California San Francisco, San Francisco, CA
| | - Donna M. Ferriero
- Departments of Pediatrics and Neurology, University of California San Francisco, San Francisco, CA
| | - Steven P. Miller
- Department of Paediatrics, Division of Neurology Hospital for Sick Children, Toronto, Ontario, Canada,Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Rollin Brant
- Department of Statistics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Emily W.Y. Tam
- Department of Paediatrics, Division of Neurology Hospital for Sick Children, Toronto, Ontario, Canada,Corresponding Author: Emily W.Y. Tam, MDCM, MAS, FRCPC, Hospital for Sick Children, Division of Neurology, 555 University Avenue, Toronto, ON M5G 1X8 Canada, Phone: 416-813-6660, Fax:416-813-6334,
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Ma D, Yu H, Xu S, Wang H, Zhang X, Ning T, Wu B. Stathmin inhibits proliferation and differentiation of dental pulp stem cells via sonic hedgehog/Gli. J Cell Mol Med 2018; 22:3442-3451. [PMID: 29655218 PMCID: PMC6009779 DOI: 10.1111/jcmm.13621] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 02/26/2018] [Indexed: 12/21/2022] Open
Abstract
The mineralization of dental pulp stem cells is an important factor in the tissue engineering of teeth, but the mechanism is not yet obvious. This study aimed to identify the effect of Stathmin on the proliferation and osteogenic/odontoblastic differentiation of human dental pulp stem cells (hDPSCs) and to explore whether the Shh signalling pathway was involved in this regulation. First, Stathmin was expressed in the cytoplasm and on the cell membranes of hDPSCs by cell immunofluorescence. Then, by constructing a lentiviral vector, the expression of Stathmin in hDPSCs was inhibited. Treatment with Stathmin shRNA (shRNA‐Stathmin group) inhibited the ability of hDPSCs to proliferate, as demonstrated by a CCK8 assay and flow cytometry analysis, and suppressed the osteogenic/odontoblastic differentiation ability, as demonstrated by alizarin red S staining and osteogenic/odontoblastic differentiation‐related gene (ALP, BSP, OCN, DSPP) activity, compared to that of hDPSCs from the control shRNA group. Molecular analyses showed that the Shh/GLI1 signalling pathway was inhibited when Stathmin was silenced, and purmorphamine, the Shh signalling pathway activator, was added to hDPSCs in the shRNA‐Stathmin group, real‐time PCR and Western blotting confirmed that expression of Shh and its downstream signalling molecules PTCH1, SMO and GLI1 increased significantly. After activating the Shh signalling pathway, the proliferation of hDPSCs increased markedly, as demonstrated by a CCK8 assay and flow cytometry analysis; osteogenic/odontoblastic differentiation‐related gene (ALP, BSP, OCN, DSPP) expression also increased significantly. Collectively, these findings firstly revealed that Stathmin‐Shh/GLI1 signalling pathway plays a positive role in hDPSC proliferation and osteogenic/odontoblastic differentiation.
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Affiliation(s)
- Dandan Ma
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,College of Stomatology, Southern Medical University, Guangzhou, China
| | - Haiyue Yu
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,College of Stomatology, Southern Medical University, Guangzhou, China
| | - Shuaimei Xu
- Department of Operative and Endodontic Dentistry, Stomatological Hospital, Southern Medical University, Guangzhou, China
| | - He Wang
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,College of Stomatology, Southern Medical University, Guangzhou, China
| | - Xiaoyi Zhang
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,College of Stomatology, Southern Medical University, Guangzhou, China
| | - Tingting Ning
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,College of Stomatology, Southern Medical University, Guangzhou, China
| | - Buling Wu
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,College of Stomatology, Southern Medical University, Guangzhou, China
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15
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Dong W, Guan F, Zhang X, Gao S, Liu N, Chen W, Zhang L, Lu D. Dhcr24 activates the PI3K/Akt/HKII pathway and protects against dilated cardiomyopathy in mice. Animal Model Exp Med 2018; 1:40-52. [PMID: 30891546 PMCID: PMC6354314 DOI: 10.1002/ame2.12007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 01/16/2018] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND 24-dehydrocholesterol reductase (Dhcr24) catalyzes the last step of cholesterol biosynthesis, which is required for normal development and anti-apoptotic activities of tissues. We found that Dhcr24 expression decreased in the cTnTR 141W dilated cardiomyopathy (DCM) transgenic mice. Therefore, we tested whether rescued expression of Dhcr24 could prevent the development of DCM and its possible mechanism. METHODS Heart tissue specific transgenic overexpression mice of Dhcr24 was generated, then was crossed to cTnTR 141W mouse to obtain the double transgenic mouse (DTG). The phenotypes were demonstrated by the survival, cardiac geometry and function analysis, as well as microstructural and ultrastructural observations based on echocardiography and histology examination. The pathway and apoptosis were analysed by western blotting and TUNEL assay in vivo and in vitro. RESULTS We find that Dhcr24 decreased in hearts tissues of cTnTR 141W and LMNAE 82K DCM mice. The transgenic overexpression of Dhcr24 significantly improves DCM phenotypes in cTnTR 141W mice, and activates PI3K/Akt/HKII pathway, followed by a reduction of the translocation of Bax and release of cytochrome c, caspase-9 and caspase-3 activation and myocyte apoptosis. Knockdown the expression of Dhcr24 reduces the activation of PI3K/Akt/HKII pathway and inhibition of the mitochondrial-dependent apoptosis. The anti-apoptotic effect of Dhcr24 could be completely removed by the inhibition of PI3K pathway and partly removed by the HKII inhibitor in H9c2 cell line. CONCLUSION Compensatory expression of Dhcr24 protect against DCM through activated PI3K/Akt/HKII pathway and reduce Bax translocation. This is the first investigation for the molecular mechanism of Dhcr24 participate in development of DCM.
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Affiliation(s)
- Wei Dong
- Key Laboratory of Human Disease Comparative MedicineNHFPCInstitute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Comparative Medical CenterPeking Union Medical CollegeBeijingChina
| | - Fei‐fei Guan
- Key Laboratory of Human Disease Comparative MedicineNHFPCInstitute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Comparative Medical CenterPeking Union Medical CollegeBeijingChina
| | - Xu Zhang
- Key Laboratory of Human Disease Comparative MedicineNHFPCInstitute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Comparative Medical CenterPeking Union Medical CollegeBeijingChina
| | - Shan Gao
- Key Laboratory of Human Disease Comparative MedicineNHFPCInstitute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Comparative Medical CenterPeking Union Medical CollegeBeijingChina
| | - Ning Liu
- Key Laboratory of Human Disease Comparative MedicineNHFPCInstitute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Comparative Medical CenterPeking Union Medical CollegeBeijingChina
| | - Wei Chen
- Key Laboratory of Human Disease Comparative MedicineNHFPCInstitute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Comparative Medical CenterPeking Union Medical CollegeBeijingChina
| | - Lian‐feng Zhang
- Key Laboratory of Human Disease Comparative MedicineNHFPCInstitute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Comparative Medical CenterPeking Union Medical CollegeBeijingChina
| | - Dan Lu
- Key Laboratory of Human Disease Comparative MedicineNHFPCInstitute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Comparative Medical CenterPeking Union Medical CollegeBeijingChina
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16
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Shi X, Wei S, Simms KJ, Cumpston DN, Ewing TJ, Zhang P. Sonic Hedgehog Signaling Regulates Hematopoietic Stem/Progenitor Cell Activation during the Granulopoietic Response to Systemic Bacterial Infection. Front Immunol 2018. [PMID: 29535725 PMCID: PMC5834434 DOI: 10.3389/fimmu.2018.00349] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Activation and reprogramming of hematopoietic stem/progenitor cells play a critical role in the granulopoietic response to bacterial infection. Our current study determined the significance of Sonic hedgehog (SHH) signaling in the regulation of hematopoietic precursor cell activity during the host defense response to systemic bacterial infection. Bacteremia was induced in male Balb/c mice via intravenous injection (i.v.) of Escherichia coli (5 × 107 CFUs/mouse). Control mice received i.v. saline. SHH protein level in bone marrow cell (BMC) lysates was markedly increased at both 24 and 48 h of bacteremia. By contrast, the amount of soluble SHH ligand in marrow elutes was significantly reduced. These contrasting alterations suggested that SHH ligand release from BMCs was reduced and/or binding of soluble SHH ligand to BMCs was enhanced. At both 12 and 24 h of bacteremia, SHH mRNA expression by BMCs was significantly upregulated. This upregulation of SHH mRNA expression was followed by a marked increase in SHH protein expression in BMCs. Activation of the ERK1/2–SP1 pathway was involved in mediating the upregulation of SHH gene expression. The major cell type showing the enhancement of SHH expression in the bone marrow was lineage positive cells. Gli1 positioned downstream of the SHH receptor activation serves as a key component of the hedgehog (HH) pathway. Primitive hematopoietic precursor cells exhibited the highest level of baseline Gli1 expression, suggesting that they were active cells responding to SHH ligand stimulation. Along with the increased expression of SHH in the bone marrow, expression of Gli1 by marrow cells was significantly upregulated at both mRNA and protein levels following bacteremia. This enhancement of Gli1 expression was correlated with activation of hematopoietic stem/progenitor cell proliferation. Mice with Gli1 gene deletion showed attenuation in activation of marrow hematopoietic stem/progenitor cell proliferation and inhibition of increase in blood granulocytes following bacteremia. Our results indicate that SHH signaling is critically important in the regulation of hematopoietic stem/progenitor cell activation and reprogramming during the granulopoietic response to serious bacterial infection.
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Affiliation(s)
- Xin Shi
- Department of Integrative Medical Sciences, College of Medicine, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Shengcai Wei
- Department of Dermatology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Kevin J Simms
- Department of Integrative Medical Sciences, College of Medicine, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Devan N Cumpston
- Department of Integrative Medical Sciences, College of Medicine, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Thomas J Ewing
- Department of Integrative Medical Sciences, College of Medicine, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Ping Zhang
- Department of Integrative Medical Sciences, College of Medicine, Northeast Ohio Medical University, Rootstown, OH, United States
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17
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Borah A, Raveendran S, Rochani A, Maekawa T, Kumar DS. Targeting self-renewal pathways in cancer stem cells: clinical implications for cancer therapy. Oncogenesis 2015; 4:e177. [PMID: 26619402 PMCID: PMC4670961 DOI: 10.1038/oncsis.2015.35] [Citation(s) in RCA: 137] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 09/10/2015] [Accepted: 09/22/2015] [Indexed: 12/21/2022] Open
Abstract
Extensive cancer research in the past few decades has identified the existence of a rare subpopulation of stem cells in the grove of cancer cells. These cells are known as the cancer stem cells marked by the presence of surface biomarkers, multi-drug resistance pumps and deregulated self-renewal pathways (SRPs). They have a crucial role in provoking cancer cells leading to tumorigenesis and its progressive metastasis. Cancer stem cells (CSCs) are much alike to normal stem cells in their self-renewal mechanisms. However, deregulations in the SRPs are seen in CSCs, making them resistant to conventional chemotherapeutic agents resulting in the tumor recurrence. Current treatment strategies in cancer fail to detect and differentiate the CSCs from their non-tumorigenic progenies owing to absence of specific biomarkers. Now, it has become imperative to understand complex functional biology of CSCs, especially the signaling pathways to design improved treatment strategies to target them. It is hopeful that the SRPs in CSCs offer a promising target to alter their survival strategies and impede their tumorigenic potential. However, there are many perils associated with the direct targeting method by conventional therapeutic agents such as off targets, poor bioavailability and poor cellular distribution. Recent evidences have shown an increased use of small molecule antagonists directly to target these SRPs may lead to severe side-effects. An alternative to solve these issues could be an appropriate nanoformulation. Nanoformulations of these molecules could provide an added advantage for the selective targeting of the pathways especially Hedgehog, Wnt, Notch and B-cell-specific moloney murine leukemia virus integration site 1 in the CSCs while sparing the normal stem cells. Hence, to achieve this goal a complete understanding of the molecular pathways corroborate with the use of holistic nanosystem (nanomaterial inhibition molecule) could possibly be an encouraging direction for future cancer therapy.
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Affiliation(s)
- A Borah
- Bio Nano Electronics Research Center, Graduate School of Interdisciplinary New Science, Toyo University, Kawagoe, Saitama, Japan
| | - S Raveendran
- Bio Nano Electronics Research Center, Graduate School of Interdisciplinary New Science, Toyo University, Kawagoe, Saitama, Japan
| | - A Rochani
- Bio Nano Electronics Research Center, Graduate School of Interdisciplinary New Science, Toyo University, Kawagoe, Saitama, Japan
| | - T Maekawa
- Bio Nano Electronics Research Center, Graduate School of Interdisciplinary New Science, Toyo University, Kawagoe, Saitama, Japan
| | - D S Kumar
- Bio Nano Electronics Research Center, Graduate School of Interdisciplinary New Science, Toyo University, Kawagoe, Saitama, Japan
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18
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Statins activate the canonical hedgehog-signaling and aggravate non-cirrhotic portal hypertension, but inhibit the non-canonical hedgehog signaling and cirrhotic portal hypertension. Sci Rep 2015; 5:14573. [PMID: 26412302 PMCID: PMC4585958 DOI: 10.1038/srep14573] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 09/01/2015] [Indexed: 12/11/2022] Open
Abstract
Liver cirrhosis but also portal vein obstruction cause portal hypertension (PHT) and angiogenesis. This study investigated the differences of angiogenesis in cirrhotic and non-cirrhotic PHT with special emphasis on the canonical (Shh/Gli) and non-canonical (Shh/RhoA) hedgehog pathway. Cirrhotic (bile duct ligation/BDL; CCl4 intoxication) and non-cirrhotic (partial portal vein ligation/PPVL) rats received either atorvastatin (15 mg/kg; 7d) or control chow before sacrifice. Invasive hemodynamic measurement and Matrigel implantation assessed angiogenesis in vivo. Angiogenesis in vitro was analysed using migration and tube formation assay. In liver and vessel samples from animals and humans, transcript expression was analyzed using RT-PCR and protein expression using Western blot. Atorvastatin decreased portal pressure, shunt flow and angiogenesis in cirrhosis, whereas atorvastatin increased these parameters in PPVL rats. Non-canonical Hh was upregulated in experimental and human liver cirrhosis and was blunted by atorvastatin. Moreover, atorvastatin blocked the non-canonical Hh-pathway RhoA dependently in activated hepatic steallate cells (HSCs). Interestingly, hepatic and extrahepatic Hh-pathway was enhanced in PPVL rats, which resulted in increased angiogenesis. In summary, statins caused contrary effects in cirrhotic and non-cirrhotic portal hypertension. Atorvastatin inhibited the non-canonical Hh-pathway and angiogenesis in cirrhosis. In portal vein obstruction, statins enhanced the canonical Hh-pathway and aggravated PHT and angiogenesis.
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19
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Pereira J, Johnson WE, O’Brien SJ, Jarvis ED, Zhang G, Gilbert MTP, Vasconcelos V, Antunes A. Evolutionary genomics and adaptive evolution of the Hedgehog gene family (Shh, Ihh and Dhh) in vertebrates. PLoS One 2014; 9:e74132. [PMID: 25549322 PMCID: PMC4280113 DOI: 10.1371/journal.pone.0074132] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 07/29/2013] [Indexed: 12/21/2022] Open
Abstract
The Hedgehog (Hh) gene family codes for a class of secreted proteins composed of two active domains that act as signalling molecules during embryo development, namely for the development of the nervous and skeletal systems and the formation of the testis cord. While only one Hh gene is found typically in invertebrate genomes, most vertebrates species have three (Sonic hedgehog – Shh; Indian hedgehog – Ihh; and Desert hedgehog – Dhh), each with different expression patterns and functions, which likely helped promote the increasing complexity of vertebrates and their successful diversification. In this study, we used comparative genomic and adaptive evolutionary analyses to characterize the evolution of the Hh genes in vertebrates following the two major whole genome duplication (WGD) events. To overcome the lack of Hh-coding sequences on avian publicly available databases, we used an extensive dataset of 45 avian and three non-avian reptilian genomes to show that birds have all three Hh paralogs. We find suggestions that following the WGD events, vertebrate Hh paralogous genes evolved independently within similar linkage groups and under different evolutionary rates, especially within the catalytic domain. The structural regions around the ion-binding site were identified to be under positive selection in the signaling domain. These findings contrast with those observed in invertebrates, where different lineages that experienced gene duplication retained similar selective constraints in the Hh orthologs. Our results provide new insights on the evolutionary history of the Hh gene family, the functional roles of these paralogs in vertebrate species, and on the location of mutational hotspots.
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Affiliation(s)
- Joana Pereira
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Porto, Portugal
| | - Warren E. Johnson
- Smithsonian Conservation Biology Institute, National Zoological Park, Front Royal, Virginia, United States of America
| | - Stephen J. O’Brien
- Theodosius Dobzhansky Center for Genome Bioinformatics, St. Petersburg State University, St. Petersburg, Russia
- Oceanographic Center, N. Ocean Drive, Nova Southeastern University, Ft. Lauderdale, Florida, United States of America
| | - Erich D. Jarvis
- Howard Hughes Medical Institute, Department of Neurobiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Guojie Zhang
- BGI-Shenzhen, Beishan Industrial Zoon, Yantian District, Shenzhen, China
| | - M. Thomas P. Gilbert
- Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
| | - Vitor Vasconcelos
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Porto, Portugal
- Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
| | - Agostinho Antunes
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Porto, Portugal
- Department of Biology, Faculty of Sciences, University of Porto, Porto, Portugal
- * E-mail:
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20
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Chandler CM, McDougal OM. Medicinal history of North American Veratrum.. PHYTOCHEMISTRY REVIEWS : PROCEEDINGS OF THE PHYTOCHEMICAL SOCIETY OF EUROPE 2014; 13:671-694. [PMID: 25379034 PMCID: PMC4217314 DOI: 10.1007/s11101-013-9328-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Plants belonging to the genus Veratrum have been used throughout history for their medicinal properties. During the nineteenth and twentieth centuries, phytochemical investigations revealed a host of steroidal alkaloids in Veratrum species, some of which are potent bioactives. This review discusses Veratrum species that grow in North America with a focus on the medicinal history of these plants and the steroidal alkaloids they contain. While significant reviews have been devoted to singularly describing the plant species within the genus Veratrum (botany), the staggering breadth of alkaloids isolated from these and related plants (phytochemistry), and the intricacies of how the various alkaloids act on their biological targets (physiology and biochemistry), this review will straddle the margins of the aforementioned disciplines in an attempt to provide a unified, coherent picture of the Veratrum plants of North America and the medicinal uses of their bioactive steroidal alkaloids.
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Affiliation(s)
- Christopher M. Chandler
- Department of Chemistry and Biochemistry, Boise State, University, 1910 University Drive, Boise, ID 83725-1520, USA
| | - Owen M. McDougal
- Department of Chemistry and Biochemistry, Boise State, University, 1910 University Drive, Boise, ID 83725-1520, USA
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21
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Zhang Y, Dong W, Guo S, Zhao S, He S, Zhang L, Tang Y, Wang H. Lentivirus-mediated delivery of sonic hedgehog into the striatum stimulates neuroregeneration in a rat model of Parkinson disease. Neurol Sci 2014; 35:1931-40. [PMID: 25030123 DOI: 10.1007/s10072-014-1866-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 06/25/2014] [Indexed: 12/14/2022]
Abstract
Parkinson disease (PD) is a progressive neurodegenerative disorder in which the nigrostriatal pathway, consisting of dopaminergic neuronal projections from the substantia nigra to the striatum, degenerates. Viral transduction is currently the most promising in vivo strategy for delivery of therapeutic proteins into the brain for treatment of PD. Sonic hedgehog (Shh) is necessary for cell proliferation, differentiation and neuroprotection in the central nervous system. In this study, we investigated the effects of overexpressed N-terminal product of SHH (SHH-N) in a PD model rat. A lentiviral vector containing SHH-N was stereotactically injected into the striatum 24 h after a striatal 6-OHDA lesion. We found that overexpressed SHH-N attenuated behavioral deficits and reduced the loss of dopamine neurons in the substantia nigra and the loss of dopamine fibers in the striatum. In addition, fluoro-ruby-labeled nigrostriatal projections were also repaired. Together, our results demonstrate the feasibility and efficacy of using the strategy of lentivirus-mediated Shh-N delivery to delay nigrostriatal pathway degeneration. This strategy holds the potential for therapeutic application in the treatment of PD.
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Affiliation(s)
- Yi Zhang
- Department of Gynecology and Obstetrics, The Third Affiliated Hospital of Southern Medical University, Guangzhou, 510630, Guangdong, China
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22
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Lee RW, Conley SK, Gropman A, Porter FD, Baker EH. Brain magnetic resonance imaging findings in Smith-Lemli-Opitz syndrome. Am J Med Genet A 2013; 161A:2407-19. [PMID: 23918729 PMCID: PMC3787998 DOI: 10.1002/ajmg.a.36096] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 05/28/2013] [Indexed: 01/03/2023]
Abstract
Smith-Lemli-Opitz syndrome (SLOS) is a neurodevelopmental disorder caused by inborn errors of cholesterol metabolism resulting from mutations in 7-dehydrocholesterol reductase (DHCR7). There are only a few studies describing the brain imaging findings in SLOS. This study examines the prevalence of magnetic resonance imaging (MRI) abnormalities in the largest cohort of patients with SLOS to date. Fifty-five individuals with SLOS (27 M, 28 F) between age 0.17 years and 25.4 years (mean = 6.2, SD = 5.8) received a total of 173 brain MRI scans (mean = 3.1 per subject) on a 1.5T GE scanner between September 1998 and December 2003, or on a 3T Philips scanner between October 2010 and September 2012; all exams were performed at the Clinical Center of the National Institutes of Health. We performed a retrospective review of these imaging studies for both major and minor brain anomalies. Aberrant MRI findings were observed in 53 of 55 (96%) SLOS patients, with abnormalities of the septum pellucidum the most frequent (42/55, 76%) finding. Abnormalities of the corpus callosum were found in 38 of 55 (69%) patients. Other findings included cerebral atrophy, cerebellar atrophy, colpocephaly, white matter lesions, arachnoid cysts, Dandy-Walker variant, and type I Chiari malformation. Significant correlations were observed when comparing MRI findings with sterol levels and somatic malformations. Individuals with SLOS commonly have anomalies involving the midline and para-midline structures of the brain. Further studies are required to examine the relationship between structural brain abnormalities and neurodevelopmental disability in SLOS.
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Affiliation(s)
- Ryan W.Y. Lee
- Department of Neurology andDevelopmental Medicine, Kennedy Krieger Institute, Baltimore, MD
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
| | - Sandra K. Conley
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
| | - Andrea Gropman
- Department of Neurology, Children’s National Medical Center, Washington DC
| | - Forbes D. Porter
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
| | - Eva H. Baker
- Department of Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD
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23
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Pennings JLA, Theunissen PT, Piersma AH. An optimized gene set for transcriptomics based neurodevelopmental toxicity prediction in the neural embryonic stem cell test. Toxicology 2012; 300:158-67. [PMID: 22760166 DOI: 10.1016/j.tox.2012.06.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 06/22/2012] [Accepted: 06/23/2012] [Indexed: 11/16/2022]
Abstract
The murine neural embryonic stem cell test (ESTn) is an in vitro model for neurodevelopmental toxicity testing. Recent studies have shown that application of transcriptomics analyses in the ESTn is useful for obtaining more accurate predictions as well as mechanistic insights. Gene expression responses due to stem cell neural differentiation versus toxicant exposure could be distinguished using the Principal Component Analysis based differentiation track algorithm. In this study, we performed a de novo analysis on combined raw data (10 compounds, 19 exposures) from three previous transcriptomics studies to identify an optimized gene set for neurodevelopmental toxicity prediction in the ESTn. By evaluating predictions of 200,000 randomly selected gene sets, we identified genes which significantly contributed to the prediction reliability. A set of 100 genes was obtained, predominantly involved in (neural) development. Further stringency restrictions resulted in a set of 29 genes that allowed for 84% prediction accuracy (area under the curve 94%). We anticipate these gene sets will contribute to further improve ESTn transcriptomics studies aimed at compound risk assessment.
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Affiliation(s)
- Jeroen L A Pennings
- Laboratory for Health Protection Research (GBO), National Institute for Public Health and the Environment, (RIVM), Bilthoven, The Netherlands.
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24
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Abstract
The Hedgehog pathway is a critical mediator of embryonic patterning and organ development, including hematopoiesis. It influences stem cell fate, differentiation, proliferation, and apoptosis in responsive tissues. In adult organisms, hedgehog pathway activity is required for aspects of tissue maintenance and regeneration; however, there is increasing awareness that abnormal hedgehog signaling is associated with malignancy. Hedgehog signaling is critical for early hematopoietic development, but there is controversy over its role in normal hematopoiesis in adult organisms where it may be dispensable. Conversely, hedgehog signaling appears to be an important survival and proliferation signal for a spectrum of hematologic malignancies. Furthermore, hedgehog signaling may be critical for the maintenance and expansion of leukemic stem cells and therefore provides a possible mechanism to selectively target these primitive cell subpopulations, which are resistant to conventional chemotherapy. Indeed, phase 1 clinical trials of hedgehog pathway inhibitors are currently underway to test this hypothesis in myeloid leukemias. This review covers: (1) the hedgehog pathway and its role in normal and malignant hematopoiesis, (2) the recent development of clinical grade small molecule inhibitors of the pathway, and (3) the potential utility of hedgehog pathway inhibition as a therapeutic strategy in hemato-oncology.
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25
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Abstract
The Hedgehog (Hh) pathway is a conserved signalling system essential for embryonic development and for the maintenance of self-renewal pathways in progenitor cells. Mutations that deregulate Hh signalling are directly implicated in basal cell carcinoma and medulloblastoma. The mechanisms of Hh pathway activation in cancers in which no pathway mutations have been identified are less clear, but of great translational significance. Small molecule inhibitors of the pathway, many of which are in early phase clinical trials, may shed further light on this question. Canonical Hh signalling promotes the expression of target genes through the Glioma-associated oncogene (GLI) transcription factors. There is now increasing evidence suggesting that 'non-canonical' Hh signalling mechanisms, some of which are independent of GLI-mediated transcription, may be important in cancer and development. The focus of this review is to summarise some of the known mechanisms of Hh signalling as well as its emerging role in cancer.
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Affiliation(s)
- Kieren D Marini
- Monash Institute of Medical Research, Centre for Cancer Research, Monash University, Victoria, Australia
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Cianciola NL, Carlin CR, Kelley TJ. Molecular pathways for intracellular cholesterol accumulation: common pathogenic mechanisms in Niemann-Pick disease Type C and cystic fibrosis. Arch Biochem Biophys 2011; 515:54-63. [PMID: 21924233 PMCID: PMC3192251 DOI: 10.1016/j.abb.2011.08.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 08/29/2011] [Accepted: 08/30/2011] [Indexed: 12/11/2022]
Abstract
It has been less than two decades since the underlying genetic defects in Niemann-Pick disease Type C were first identified. These defects impair function of two proteins with a direct role in lipid trafficking, resulting in deposition of free cholesterol within late endosomal compartments and a multitude of effects on cell function and clinical manifestations. The rapid pace of research in this area has vastly improved our overall understanding of intracellular cholesterol homeostasis. Excessive cholesterol buildup has also been implicated in clinical manifestations associated with a number of genetically unrelated diseases including cystic fibrosis. Applying knowledge about anomalous cell signaling behavior in cystic fibrosis opens prospects for identifying similar previously unrecognized disease pathways in Niemann-Pick disease Type C. Recognition that Niemann-Pick disease Type C and cystic fibrosis both impair cholesterol regulatory pathways also provides a rationale for identifying common therapeutic targets.
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Affiliation(s)
- Nicholas L. Cianciola
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4970
| | - Cathleen R. Carlin
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4970
- Case Western Reserve University Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4970
| | - Thomas J. Kelley
- Department of Pediatrics, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4970
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Keber R, Motaln H, Wagner KD, Debeljak N, Rassoulzadegan M, Ačimovič J, Rozman D, Horvat S. Mouse knockout of the cholesterogenic cytochrome P450 lanosterol 14alpha-demethylase (Cyp51) resembles Antley-Bixler syndrome. J Biol Chem 2011; 286:29086-29097. [PMID: 21705796 DOI: 10.1074/jbc.m111.253245] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Antley-Bixler syndrome (ABS) represents a group of heterogeneous disorders characterized by skeletal, cardiac, and urogenital abnormalities that have frequently been associated with mutations in fibroblast growth factor receptor 2 or cytochrome P450 reductase genes. In some ABS patients, reduced activity of the cholesterogenic cytochrome P450 CYP51A1, an ortholog of the mouse CYP51, and accumulation of lanosterol and 24,25-dihydrolanosterol has been reported, but the role of CYP51A1 in the ABS etiology has remained obscure. To test whether Cyp51 could be involved in generating an ABS-like phenotype, a mouse knock-out model was developed that exhibited several prenatal ABS-like features leading to lethality at embryonic day 15. Cyp51(-/-) mice had no functional Cyp51 mRNA and no immunodetectable CYP51 protein. The two CYP51 enzyme substrates (lanosterol and 24,25-dihydrolanosterol) were markedly accumulated. Cholesterol precursors downstream of the CYP51 enzymatic step were not detected, indicating that the targeting in this study blocked de novo cholesterol synthesis. This was reflected in the up-regulation of 10 cholesterol synthesis genes, with the exception of 7-dehydrocholesterol reductase. Lethality was ascribed to heart failure due to hypoplasia, ventricle septum, and epicardial and vasculogenesis defects, suggesting that Cyp51 deficiency was involved in heart development and coronary vessel formation. As the most likely downstream molecular mechanisms, alterations were identified in the sonic hedgehog and retinoic acid signaling pathways. Cyp51 knock-out mice provide evidence that Cyp51 is essential for embryogenesis and present a potential animal model for studying ABS syndrome in humans.
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Affiliation(s)
- Rok Keber
- Department of Animal Science, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Helena Motaln
- Department of Animal Science, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, 1000 Ljubljana, Slovenia
| | - Kay D Wagner
- INSERM U907, Parc Valrose, Nice, France; Université de Nice, Sophia-Antipolis, Parc Valrose, Nice, France
| | - Nataša Debeljak
- Institute of Biochemistry, Centre for Functional Genomics and Bio-Chips, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Minoo Rassoulzadegan
- Université de Nice, Sophia-Antipolis, Parc Valrose, Nice, France; Centre de Biochimie, INSERM U636, Parc Valrose, Nice, France
| | - Jure Ačimovič
- Institute of Biochemistry, Centre for Functional Genomics and Bio-Chips, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Damjana Rozman
- Institute of Biochemistry, Centre for Functional Genomics and Bio-Chips, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Simon Horvat
- Department of Animal Science, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; National Institute of Chemistry, 1000 Ljubljana, Slovenia and.
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Ingham PW, Nakano Y, Seger C. Mechanisms and functions of Hedgehog signalling across the metazoa. Nat Rev Genet 2011; 12:393-406. [PMID: 21502959 DOI: 10.1038/nrg2984] [Citation(s) in RCA: 446] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Hedgehog proteins constitute one of a small number of families of secreted signals that have a central role in the development of metazoans. Genetic analyses in flies, fish and mice have uncovered the major components of the pathway that transduces Hedgehog signals, and recent genome sequence projects have provided clues about its evolutionary origins. In this Review we provide an updated overview of the mechanisms and functions of this signalling pathway, highlighting the conserved and divergent features of the pathway, as well as some of the common themes in its deployment that have emerged from recent studies.
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Affiliation(s)
- Philip W Ingham
- Institute of Molecular and Cell Biology, 61 Biopolis Drive, Singapore.
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Robinson JF, van Beelen VA, Verhoef A, Renkens MFJ, Luijten M, van Herwijnen MHM, Westerman A, Pennings JLA, Piersma AH. Embryotoxicant-Specific Transcriptomic Responses in Rat Postimplantation Whole-Embryo Culture. Toxicol Sci 2010; 118:675-85. [DOI: 10.1093/toxsci/kfq292] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Mas C, Ruiz i Altaba A. Small molecule modulation of HH-GLI signaling: current leads, trials and tribulations. Biochem Pharmacol 2010; 80:712-23. [PMID: 20412786 DOI: 10.1016/j.bcp.2010.04.016] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Revised: 04/12/2010] [Accepted: 04/13/2010] [Indexed: 01/07/2023]
Abstract
Many human sporadic cancers have been recently shown to require the activity of the Hedgehog-GLI pathway for sustained growth. The survival and expansion of cancer stem cells is also HH-GLI dependent. Here we review the advances on the modulation of HH-GLI signaling by small molecules. We focus on both natural compounds and synthetic molecules that target upstream pathway components, mostly SMOOTHENED, and those that target the last steps of the pathway, the GLI transcription factors. In this review we have sought to provide some bases for useful comparisons, listing original assays used and sources to facilitate comparisons of IC50 values. This area is a rapidly expanding field where biology, medicine and chemistry intersect, both in academia and industry. We also highlight current clinical trials, with positive results in early stages. While we have tried to be exhaustive regarding the molecules, not all data is in the public domain yet. Indeed, we have opted to avoid listing chemical structures but these can be easily found in the references given. Finally, we are hopeful that the best molecules will soon reach the patients but caution about the lack of investment on compounds that lack tight IP positions. While the market in developed nations is expected to compensate the investment and risk of making HH-GLI modulators, other sources or plans must be available for developing nations and poor patient populations. The promise of curing cancer recalls the once revered dream of El Dorado, which taught us that not everything that GLI-tters is gold.
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Affiliation(s)
- Christophe Mas
- Department of Genetic Medicine and Development, University of Geneva Medical School, 1 rue Michel Servet, CH-1211 Geneva, Switzerland.
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Stanton BZ, Peng LF. Small-molecule modulators of the Sonic Hedgehog signaling pathway. MOLECULAR BIOSYSTEMS 2009; 6:44-54. [PMID: 20024066 DOI: 10.1039/b910196a] [Citation(s) in RCA: 164] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Sonic hedgehog (Shh) is the most widely characterized of the three vertebrate Hedgehog homologs, and is essential for proper embryonic development. Shh binds to its receptor, Patched (Ptch1), resulting in the de-repression of Smoothened (Smo). This leads to the activation of Gli2, which regulates the transcription of target genes that include Gli1 and Ptch1. Several synthetic and naturally occurring small-molecule modulators of Smo have been discovered. Shh-signaling antagonists that bind to Smo include cyclopamine, SANT1, and Cur-61414. Shh signaling agonists that bind to Smo include the synthetic small molecules purmorphamine and SAG. Small molecules that inhibit Shh signaling downstream of Smo, GANT58 and GANT61 have also been reported. Robotnikinin inhibits the Shh pathway by directly targeting Shh. Although progress has been made in understanding and modulating Shh signaling, fundamental aspects of Shh signal transduction remain obscure, including the mechanism(s) whereby Ptch1 regulates Smo activity. Small-molecule modulators of Shh signaling provide a means to regulate the activity of a pathway implicated in medulloblastoma, basal cell carcinoma (BCC), pancreatic cancer, prostate cancer and developmental disorders. Several Shh inhibitors have not succeeded in the clinic for unknown reasons, but clinical trials in BCC and pancreatic cancer with the promising Smo antagonists GDC-0449 and IPI-926 are currently underway.
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Affiliation(s)
- Benjamin Z Stanton
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA
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Edison R, Muenke M. The interplay of genetic and environmental factors in craniofacial morphogenesis: holoprosencephaly and the role of cholesterol. Clin Genet 2008. [DOI: 10.1111/j.1399-0004.2003.tb02302.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Breitling R. Greased hedgehogs: new links between hedgehog signaling and cholesterol metabolism. Bioessays 2008; 29:1085-94. [PMID: 17935218 DOI: 10.1002/bies.20663] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The close link between signaling by the developmental regulators of the Hedgehog family and cholesterol biochemistry has been known for some time. The morphogen is covalently attached to cholesterol in a peculiar autocatalytic reaction and embryonal disruption of cholesterol synthesis leads to malformations that mimic Hh signaling defects. Recently, it was furthermore shown that secreted Hh could hitchhike on lipoprotein particles to establish its morphogenic gradient in the developing embryo. Additionally, there is new evidence that the Hh-receptor Patched transmits the Hh signal by modulating the secretion of an inhibitory sterol molecule from the receiving cells. Here we present some of the most recent discoveries on the Hh-sterol link and discuss their implications from a systems design perspective. We predict that a robust functioning of the Hh pathway will require the involvement of more sterol metabolites, and these should be the subject of future research.
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Affiliation(s)
- Rainer Breitling
- Groningen Bioinformatics Centre, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9751 NN Haren, The Netherlands.
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35
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Hao L, Mukherjee K, Liegeois S, Baillie D, Labouesse M, Bürglin TR. The hedgehog-related gene qua-1 is required for molting in Caenorhabditis elegans. Dev Dyn 2007; 235:1469-81. [PMID: 16502424 DOI: 10.1002/dvdy.20721] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Caenorhabditis elegans genome encodes ten proteins that share similarity with Hedgehog through the C-terminal Hint/Hog domain. While most genes are members of larger gene families, qua-1 is a single copy gene. Here we show that orthologs of qua-1 exist in many nematodes, including Brugia malayi, which shared a common ancestor with C. elegans about 300 million years ago. The QUA-1 proteins contain an N-terminal domain, the Qua domain, that is highly conserved, but whose molecular function is not known. We have studied the expression pattern of qua-1 in C. elegans using a qua-1::GFP transcriptional fusion. qua-1 is mainly expressed in hyp1 to hyp11 hypodermal cells, but not in seam cells. It is also expressed in intestinal and rectal cells, sensilla support cells, and the P cell lineage in L1. The expression of qua-1::GFP undergoes cyclical changes during development in phase with the molting cycle. It accumulates prior to molting and disappears between molts. Disruption of the qua-1 gene function through an internal deletion that causes a frame shift with premature stop in the middle of the gene results in strong lethality. The animals arrest in the early larval stages due to defects in molting. Electron microscopy reveals double cuticles due to defective ecdysis, but no obvious defects are seen in the hypodermis. Qua domain-only::GFP and full-length QUA-1::GFP fusion constructs are secreted and associated with the overlying cuticle, but only QUA-1::GFP rescues the mutant phenotype. Our results suggest that both the Hint/Hog domain and Qua domain are critically required for the function of QUA-1.
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Affiliation(s)
- Limin Hao
- Department of Biosciences and Nutrition, and Center for Genomics and Bioinformatics, Karolinska Institutet, Huddinge, Sweden
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Tuncer MC, Ozturk H, Buyukbayram H, Ozturk H. Interaction of L-Arginine-methyl ester and Sonic hedgehog in liver ischemia-reperfusion injury in the rats. World J Gastroenterol 2007; 13:3841-6. [PMID: 17657839 PMCID: PMC4611217 DOI: 10.3748/wjg.v13.i28.3841] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the role of Sonic hedgehog (Shh) on the course of liver ischemia and reperfusion (I/R) in rats, and the interaction between treatment with nitric oxide donor L-Arginine-methyl ester (L-Arg) and up-regulation of Shh expression.
METHODS: A total of 30 male Sprague-Dawley rats weighing 220-240 g were used in this study. Sham-control group (G1, n = 10): a sham operation was performed (except for liver I/R). I/R-untreated group (G2, n = 10): rats underwent liver ischemia for 1 h followed by reperfusion for 45 min. I/R-L-Arg group (G3, n = 10): after performing the same surgical procedure as in group 2, animals were treated with L-Arg. Liver tissues were taken for determination of malondialdehyde (MDA) levels, and biochemical and histological evaluations were made.
RESULTS: Plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and γ-glutamyltranspeptidase (GGT) activities were higher in group 2 than in group 3. MDA values and the hepatic injury score decreased in the L-Arg treated group compared to the I/R-untreated group. In group 2, the hepatocytes were swollen with marked vacuolization. Group 3 rats showed well-preserved liver parenchyma, with hepatocytes extending from the central vein. The morphology of the hepatocytes and the sinusoidal structures was normal, without any signs of congestion. Mild Shh positive immunostaining was detected in group 2 animals. The expression of immunoreactive cells was increased markedly in liver tissue from I/R-L-Arg rats.
CONCLUSION: Our findings suggest that Shh molecules are critical factors in the pathophysiology of inflammatory liver injury induced by I/R. In addition, NO plays an important role in the immunohistochemical expression of these molecules.
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Affiliation(s)
- Mehmet-Cudi Tuncer
- Dicle University, Medical School, Departments of Anatomy, Diyarbakir, Turkey
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37
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Templeton TJ. Whole-genome natural histories of apicomplexan surface proteins. Trends Parasitol 2007; 23:205-12. [PMID: 17350340 DOI: 10.1016/j.pt.2007.03.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Revised: 02/01/2007] [Accepted: 03/02/2007] [Indexed: 11/19/2022]
Abstract
The natural histories of free-living and pathogenic protozoans have been described in over a century of studies, spanning a range of disciplines such as microscopic, cellular, taxonomic, pathological, clinical and molecular. Only in the last decade has this landscape of work benefited from the availability of whole-genome nucleotide sequence data. For many pathogens, it is now possible to overlay analyses of protein repertoires onto the current spectrum of knowledge. This article illuminates protozoan natural histories, particularly the rapidly evolving and highly adaptive direct physical interface of apicomplexan parasites and their hosts, by providing a brief introduction to the origin and phylogenetic distribution of parasite-encoded surface proteins and their component domains.
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Affiliation(s)
- Thomas J Templeton
- Weill Cornell Medical College, Department of Microbiology and Immunology, 1300 York Avenue, Box 62, New York, NY 10021, USA.
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Mirza R, Hayasaka S, Takagishi Y, Kambe F, Ohmori S, Maki K, Yamamoto M, Murakami K, Kaji T, Zadworny D, Murata Y, Seo H. DHCR24 gene knockout mice demonstrate lethal dermopathy with differentiation and maturation defects in the epidermis. J Invest Dermatol 2006; 126:638-47. [PMID: 16410790 DOI: 10.1038/sj.jid.5700111] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Desmosterolosis is an autosomal recessive disorder due to mutations in the 3beta-hydroxysterol-Delta24 reductase (DHCR24) gene that encodes an enzyme catalyzing the conversion of desmosterol to cholesterol. To date, only two patients have been reported with severe developmental defects including craniofacial abnormalities and limb malformations. We employed mice with targeted disruption of DHCR24 to understand the pathophysiology of desmosterolosis. All DHCR24-/- mice died within a few hours after birth. Their skin was wrinkleless and less pliant, leading to restricted movement and inability to suck (empty stomach). DHCR24 gene was expressed abundantly in the epidermis of control but not of DHCR24-/- mice. Accordingly, cholesterol was not detected whereas desmosterol was abundant in the epidermis of DHCR24-/- mice. Skin histology revealed thickened epidermis with few and smaller keratohyaline granules. Aberrant expression of keratins such as keratins 6 and 14 suggested hyperproliferative hyperkeratosis with undifferentiated keratinocytes throughout the epidermis. Altered expression of filaggrin, loricrin, and involcrin were also observed in the epidermis of DHCR24-/-. These findings suggested impaired skin barrier function. Indeed, increased trans-epidermal water loss and permeability of Lucifer yellow were observed in DHCR24-/- mice. DHCR24 thus plays crucial role for skin development and its proper function.
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Affiliation(s)
- Rusella Mirza
- Department of Molecular and Cellular Adaptation, Research Institute of Environmental Medicine, Nagoya University, Chikusa-ku, Nagoya, Japan
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Dawber RJ, Hebbes S, Herpers B, Docquier F, van den Heuvel M. Differential range and activity of various forms of the Hedgehog protein. BMC DEVELOPMENTAL BIOLOGY 2005; 5:21. [PMID: 16197551 PMCID: PMC1266354 DOI: 10.1186/1471-213x-5-21] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2005] [Accepted: 09/30/2005] [Indexed: 12/21/2022]
Abstract
Background The Hedgehog (Hh) family of secreted proteins act as extracellular messengers to control and coordinate growth and differentiation. The mechanism by which Hh protein travels across a field of cells, and results in a range of specific effects relating to the distance from the source, has been the subject of much debate. It has been suggested that the range and activity of the pathway can be linked to modifications of the Hh protein, specifically the addition of lipid groups at N- and C-terminal sites. Results Here we have addressed the potency of different forms of Hh protein by expressing these in Drosophila, where we are able to precisely establish pathway activity and range in naïve but responsive tissues. As expected, a construct that can produce all forms of Hh recapitulates endogenous signaling potencies. In comparison, expression of a form that lacks the cholesterol moiety (HhN) leads to an extended range, but the product is less effective at inducing maximal Hh responses. Expression of a point mutant that lacks the N-terminal palmitate binding site shows that the palmitoylation of Hh is absolutely required for activity in this system. Conclusion We conclude that the addition of the cholesterol moiety limits the range of the protein and is required for maximal activity, while addition of palmitate is required for all activity. These findings have implications for understanding how Hedgehog proteins move, and thus their potential at influencing distant sites, and concomitantly, how modifications of the signaling protein can affect the efficacy of the response in exposed cells.
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Affiliation(s)
- Rebecca J Dawber
- MRC Functional Genetics Unit, Department of Human Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Stephen Hebbes
- MRC Functional Genetics Unit, Department of Human Anatomy and Genetics, University of Oxford, Oxford, UK
- Cell and Molecular Biosciences, University of Newcastle, Newcastle-upon-Tyne, UK
| | - Bram Herpers
- MRC Functional Genetics Unit, Department of Human Anatomy and Genetics, University of Oxford, Oxford, UK
- Cell Biology, UMC Utrecht, Utrecht, The Netherlands
| | - France Docquier
- MRC Functional Genetics Unit, Department of Human Anatomy and Genetics, University of Oxford, Oxford, UK
- Department of Biological Sciences, University of Essex, Colchester, UK
| | - Marcel van den Heuvel
- MRC Functional Genetics Unit, Department of Human Anatomy and Genetics, University of Oxford, Oxford, UK
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Abstract
The Hedgehog (Hh)-signaling pathway is essential for numerous developmental processes in Drosophila and vertebrate embryos. Hh signal transduction encompasses a complex series of regulatory events, including the generation of the mature Hh ligand, propagation of the ligand from source of production as well as the reception and interpretation of the signal in Hh-receiving cells. Many congenital malformations in humans are known to involve mutations in various components of the Hh-signaling pathway. This mini review summarizes some recent findings about the regulation of Hh signal transduction and describes the spectrum of human congenital malformations that are associated with aberrant Hh signaling. Based on a comparison of mouse-mutant phenotypes and human syndromes, we discuss how Hh-dependent Gli activator and repressor functions contribute to some of the congenital malformations.
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Affiliation(s)
- E Nieuwenhuis
- Program in Developmental Biology, The Hospital for Sick Children, Department of Molecular and Medical Genetics, University of Toronto, Toronto, Ontario MG5 1X8, Canada
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Yu H, Wessels A, Tint GS, Patel SB. Partial rescue of neonatal lethality of Dhcr7 null mice by a nestin promoter-driven DHCR7 transgene expression. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2005; 156:46-60. [PMID: 15862627 DOI: 10.1016/j.devbrainres.2005.01.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2004] [Revised: 01/27/2005] [Accepted: 01/30/2005] [Indexed: 11/20/2022]
Abstract
In humans, genetic disorders affecting post-squalene cholesterol biosynthesis result in a variety of dysmorphology syndromes. One key feature of all of these is the presence of mental retardation and another is the lack of a robust genotype-phenotype correlation. Knockout mice defective in the 3beta hydroxysterol Delta7 reductase (Dhcr7), a model for the most common of such disorders in humans, the Smith-Lemli-Opitz syndrome, all die within 24 h of birth. The cause of this postnatal mortality in these mice has not been fully established. In the present study, we tested the hypothesis that CNS dysfunction was a major cause of this lethality and investigated whether transgenic expression of normal human DHCR7 in neuronal tissues could rescue this neonatal lethality. Transgenic mice, expressing DHCR7 driven by murine nestin promoter, were bred onto Dhcr7 knock-out (Dhcr7(-1-)) background and resulted in a partial rescue of neonatal lethality in 11 of 91 (12%) of transgene-positive Dhcr7(-1-) pups. Despite biochemical analyses that showed continued profound cholesterol deficiency in brain, rescued animals survived between 3 and 17 days. Thus, one important conclusion to be drawn is that defects in CNS in Dhcr7 knockout mice may contribute to the early lethality. Another conclusion is that even small and subtle changes in the brain sterol metabolism were sufficient to enable rescue. These data also provide important clues as to the cause of the variable expressivity seen in SLOS.
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Affiliation(s)
- Hongwei Yu
- Division of Endocrinology, Diabetes and Medical Genetics, Medical University of South Carolina, STR 541, 114 Doughty Street, Charleston, SC 29403, USA.
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Wolf G. The function of cholesterol in embryogenesis. J Nutr Biochem 2005; 10:188-92. [PMID: 15539288 DOI: 10.1016/s0955-2863(98)00102-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/1998] [Accepted: 12/08/1998] [Indexed: 11/20/2022]
Abstract
Cholesterol is critical in embryonic development. Inhibition of cholesterol synthesis in experimental animals has caused a birth defect called holoprosencephaly (HPE), which is evidenced by cyclopia (one eye in the middle of the face), monorhinia (protruding single nose above the eye), absence of the pituitary gland, and central nervous system (CNS) abnormalities. In humans, an inherited defect in the cholesterol-synthesizing enzyme 7-dehydrocholesterol reductase depletes cholesterol and results in human HPE, termed Smith-Lemli-Opitz syndrome. In its most severe form, the syndrome leads to cyclopia, monorhinia, and lack of separation of cerebral hemispheres. The cause of the syndrome is a defect in a protein coded by the gene Sonic hedgehog (SHH). The protein SHH is expressed in the notochord of the CNS in the early embryo and is activated by being cleaved autocatalytically, with simultaneous covalent attachment of cholesterol to the N-terminal fragment, which is secreted by cells of the mesoderm layer, signaling the establishment of the neural midline cells. Thus, cholesterol is essential for proper signaling in the development of the normal embryo.
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Affiliation(s)
- G Wolf
- Department of Nutritional Sciences, University of California, Berkeley, CA 94720, USA
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Abstract
Secreted signaling proteins function in a diverse array of essential patterning events during metazoan development, ranging from embryonic segmentation in insects to neural tube differentiation in vertebrates. These proteins generally are expressed in a localized manner, and they may elicit distinct concentration-dependent responses in the cells of surrounding tissues and structures, thus functioning as morphogens that specify the pattern of cellular responses by their tissue distribution. Given the importance of signal distribution, it is notable that the Hedgehog (Hh) and Wnt proteins, two of the most important families of such signals, are known to be covalently modified by lipid moieties, the membrane-anchoring properties of which are not consistent with passive models of protein mobilization within tissues. This review focuses on the mechanisms underlying biogenesis of the mature Hh proteins, which are dually modified by cholesteryl and palmitoyl adducts, as well as on the relationship between Hh proteins and the self-splicing proteins (i.e., proteins containing inteins) and the Hh-like proteins of nematodes. We further discuss the cellular mechanisms that have evolved to handle lipidated Hh proteins in the spatial deployment of the signal in developing tissues and the more recent findings that implicate palmitate modification as an important feature of Wnt signaling proteins.
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Affiliation(s)
- Randall K Mann
- Department of Molecular Biology and Genetics and Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
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Abstract
Hedgehog proteins are of pivotal importance for development and maintenance of tissue patterns in adult organisms. Despite the role of Hedgehogs in differentiation and tumorigenesis, signal transduction of Hedgehog remains a relatively uncharted area of signalling biochemistry. For proper Hedgehog distribution into tissues, two highly unusual covalent modifications are necessary, palmitoylation of a secreted protein and the attachment of a cholesterol group, making Hedgehog the only established sterolated protein in nature. Hedgehog exerts its function via two membrane-bound receptors, Patched and Smoothened; presumably, Patched transports a cholesterol derivate out of cells which inhibits Smoothened. Binding of Hedgehog to Patched impedes this proposed pump function and thus Inhibition of Smoothened, which leads to expression of genetic Hedgehog targets via relief of transcriptional repression. These atypical features make Hedgehog physiology unique in biology and may explain why this field has attracted such significant attention.
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Affiliation(s)
- Maarten F Bijlsma
- Laboratory for Experimental Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands
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45
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Abstract
Hematopoiesis and vasculogenesis in the mammalian embryo begin in the blood islands of the yolk sac and continue, somewhat later, within the embryo proper. A subset of the first endothelial and hematopoietic cells of the yolk sac arise in close spatial and temporal association, apparently from a common mesodermal progenitor, the "hemangioblast." The mechanisms that control formation of hemangioblast and embryonic hematopoietic and endothelial (angioblastic) stem/progenitor cells are still not well understood. Formation of these cell types from nascent mesoderm requires signals from an adjacent outer layer of primitive (visceral) endoderm. Indian hedgehog (Ihh), a member of the hedgehog family of extracellular morphogens, is secreted by visceral endoderm and alone is sufficient to induce hematopoiesis and vasculogenesis in explanted embryos. While gene targeting studies in mice support a role for hedgehog signaling in these processes in vivo, they also suggest that additional molecules (perhaps, for example, Wnt proteins) are required for induction and patterning of hematopoietic and vascular mesoderm. Indian hedgehog likely functions through upregulation of genes encoding other signaling molecules, such as bone morphogenetic protein (Bmp)-4, in the target tissue. This review will focus on hematopoietic and vascular development in the early mouse embryo and will discuss potential implications of recent studies for stem cell transplantation in humans.
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Affiliation(s)
- Margaret H Baron
- Department of Medicine, Molecular, Brookdale Department of Cell and Developmental Biology, Ruttenberg Cancer Center, Mount Sinai School of Medicine, 1425 Madison Avenue 11-70B, Box 1079, New York, NY 10029, USA.
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46
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Abstract
During the last decade, many of the factors and mechanisms controlling membrane and protein trafficking in general and endocytic trafficking in particular have been uncovered. We have a detailed understanding of the different endocytic trafficking steps: plasma membrane budding, endocytic vesicle motility and fusion with the endosome, recycling, transcytosis and lysosomal degradation. The kinetics and trafficking pathway of many signaling receptors and the relevance of endocytic trafficking during signaling in many mammalian cultured cells are also well understood. However, only in recent years has the role of endocytic trafficking during cell-to-cell communication during development, i.e. during patterning, induction and lateral inhibition, begun to be explored. The contribution of Drosophila developmental genetics and cell biology has been fundamental in elucidating the essential role of endocytosis during these processes. Reviewed here are some of the recent developments on the role of endocytic trafficking during long- and short-range signaling and during lateral inhibition.
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Affiliation(s)
- Marcos González-Gaitán
- Max-Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, Dresden D-01307, Germany.
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Laubner D, Breitling R, Adamski J. Embryonic expression of cholesterogenic genes is restricted to distinct domains and colocalizes with apoptotic regions in mice. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2003; 115:87-92. [PMID: 12824059 DOI: 10.1016/s0169-328x(03)00094-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Cholesterol biosynthesis has been assumed to be an ubiquitous process in vertebrate organisms. Here we present data demonstrating that expression of key enzymes of cholesterol biosynthesis is restricted to specific tissues during embryonic development. Distinct expression starts in the dorsal neural tube at embryonic day 8 and is later detected in dorsal root and cephalic ganglia, in the pharyngeal pouches and limb buds. In the limb, expression becomes progressively restricted to interdigital regions during differentiation. Caspase3 whole mount immunostaining revealed that cholesterol biosynthesis colocalizes with apoptotic regions that are targets of the morphogenic signal Sonic hedgehog. This expression pattern correlates closely with the shared phenotypic features of cholesterol biosynthesis and hedgehog mutants.
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Affiliation(s)
- Daniela Laubner
- Institute of Experimental Genetics, GSF-National Research Center for Environment and Health, 85764 Neuherberg, Germany
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Cooper MK, Wassif CA, Krakowiak PA, Taipale J, Gong R, Kelley RI, Porter FD, Beachy PA. A defective response to Hedgehog signaling in disorders of cholesterol biosynthesis. Nat Genet 2003; 33:508-13. [PMID: 12652302 DOI: 10.1038/ng1134] [Citation(s) in RCA: 302] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2002] [Accepted: 02/28/2003] [Indexed: 11/08/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS), desmosterolosis and lathosterolosis are human syndromes caused by defects in the final stages of cholesterol biosynthesis. Many of the developmental malformations in these syndromes occur in tissues and structures whose embryonic patterning depends on signaling by the Hedgehog (Hh) family of secreted proteins. Here we report that response to the Hh signal is compromised in mutant cells from mouse models of SLOS and lathosterolosis and in normal cells pharmacologically depleted of sterols. We show that decreasing levels of cellular sterols correlate with diminishing responsiveness to the Hh signal. This diminished response occurs at sterol levels sufficient for normal autoprocessing of Hh protein, which requires cholesterol as cofactor and covalent adduct. We further find that sterol depletion affects the activity of Smoothened (Smo), an essential component of the Hh signal transduction apparatus.
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Affiliation(s)
- Michael K Cooper
- Department of Molecular Biology and Genetics, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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Edison R, Muenke M. The interplay of genetic and environmental factors in craniofacial morphogenesis: holoprosencephaly and the role of cholesterol. Congenit Anom (Kyoto) 2003; 43:1-21. [PMID: 12692399 DOI: 10.1111/j.1741-4520.2003.tb01022.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Cyclopia, the paradigmatic "face [that] predicts the brain" in severe holoprosencephaly (HPE) (DeMyer et al., 1964), has been recognized since ancient times. Descriptive embryologists and pathologists have noted the continuum of defective separation of the forebrain and loss of central nervous system (CNS) midline structures for more than a century. It has been recognized more recently that inhibitors of cholesterol biosynthesis, whether consumed in native plants by range sheep, or experimentally applied to early embryos, could phenocopy the natural malformation, as could a variety of other teratogens (maternal diabetes, alcohol). Yet it has been less than a decade that the genomic knowledge base and powerful analytic methods have brought the sciences of descriptive, molecular, and genetic embryology within range of each other. In this review, we discuss the clinical presentations and pathogenesis of HPE. We will outline various genetic and teratogenic mechanisms leading to HPE. Lastly, we will attempt to examine the pivotal role of cholesterol and the Sonic Hedgehog (Shh) pathway in this disorder and in normal embryonic forebrain development.
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Affiliation(s)
- Robin Edison
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, USA
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50
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Gallet A, Rodriguez R, Ruel L, Therond PP. Cholesterol modification of hedgehog is required for trafficking and movement, revealing an asymmetric cellular response to hedgehog. Dev Cell 2003; 4:191-204. [PMID: 12586063 DOI: 10.1016/s1534-5807(03)00031-5] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Hedgehog family members are secreted proteins involved in numerous patterning mechanisms. Different posttranslational modifications have been shown to modulate Hedgehog biological activity. We investigated the role of these modifications in regulating subcellular localization of Hedgehog in the Drosophila embryonic epithelium. We demonstrate that cholesterol modification of Hedgehog is responsible for its assembly in large punctate structures and apical sorting through the activity of the sterol-sensing domain-containing Dispatched protein. We further show that movement of these specialized structures through the cellular field is contingent upon the activity of proteoglycans synthesized by the heparan sulfate polymerase Tout-Velu. Finally, we show that the Hedgehog large punctate structures are necessary only for a subset of Hedgehog target genes across the parasegmental boundary, suggesting that presentation of Hedgehog from different membrane compartments is responsible for Hedgehog functional diversity in epithelial cells.
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Affiliation(s)
- Armel Gallet
- Institute of Signaling, Developmental Biology and Cancer Research, CNRS UMR 6543, Centre de Biochimie, Parc Valrose, 06108 Nice Cedex 02, France
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