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Zubrzycki M, Schramm R, Costard-Jäckle A, Grohmann J, Gummert JF, Zubrzycka M. Cardiac Development and Factors Influencing the Development of Congenital Heart Defects (CHDs): Part I. Int J Mol Sci 2024; 25:7117. [PMID: 39000221 PMCID: PMC11241401 DOI: 10.3390/ijms25137117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Revised: 06/20/2024] [Accepted: 06/25/2024] [Indexed: 07/16/2024] Open
Abstract
The traditional description of cardiac development involves progression from a cardiac crescent to a linear heart tube, which in the phase of transformation into a mature heart forms a cardiac loop and is divided with the septa into individual cavities. Cardiac morphogenesis involves numerous types of cells originating outside the initial cardiac crescent, including neural crest cells, cells of the second heart field origin, and epicardial progenitor cells. The development of the fetal heart and circulatory system is subject to regulatation by both genetic and environmental processes. The etiology for cases with congenital heart defects (CHDs) is largely unknown, but several genetic anomalies, some maternal illnesses, and prenatal exposures to specific therapeutic and non-therapeutic drugs are generally accepted as risk factors. New techniques for studying heart development have revealed many aspects of cardiac morphogenesis that are important in the development of CHDs, in particular transposition of the great arteries.
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Affiliation(s)
- Marek Zubrzycki
- Department of Surgery for Congenital Heart Defects, Heart and Diabetes Center NRW, University Hospital, Ruhr-University Bochum, Georgstr. 11, 32545 Bad Oeynhausen, Germany;
| | - Rene Schramm
- Clinic for Thoracic and Cardiovascular Surgery, Heart and Diabetes Center NRW, University Hospital, Ruhr-University Bochum, Georgstr. 11, 32545 Bad Oeynhausen, Germany; (R.S.); (A.C.-J.); (J.F.G.)
| | - Angelika Costard-Jäckle
- Clinic for Thoracic and Cardiovascular Surgery, Heart and Diabetes Center NRW, University Hospital, Ruhr-University Bochum, Georgstr. 11, 32545 Bad Oeynhausen, Germany; (R.S.); (A.C.-J.); (J.F.G.)
| | - Jochen Grohmann
- Department of Congenital Heart Disease/Pediatric Cardiology, Heart and Diabetes Center NRW, University Hospital, Ruhr-University Bochum, Georgstr. 11, 32545 Bad Oeynhausen, Germany;
| | - Jan F. Gummert
- Clinic for Thoracic and Cardiovascular Surgery, Heart and Diabetes Center NRW, University Hospital, Ruhr-University Bochum, Georgstr. 11, 32545 Bad Oeynhausen, Germany; (R.S.); (A.C.-J.); (J.F.G.)
| | - Maria Zubrzycka
- Department of Clinical Physiology, Faculty of Medicine, Medical University of Lodz, Mazowiecka 6/8, 92-215 Lodz, Poland
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Zhang Y, Ramirez-Martinez A, Chen K, McAnally JR, Cai C, Durbacz MZ, Chemello F, Wang Z, Xu L, Bassel-Duby R, Liu N, Olson EN. Net39 protects muscle nuclei from mechanical stress during the pathogenesis of Emery-Dreifuss muscular dystrophy. J Clin Invest 2023; 133:e163333. [PMID: 37395273 PMCID: PMC10313361 DOI: 10.1172/jci163333] [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: 07/06/2022] [Accepted: 05/16/2023] [Indexed: 07/04/2023] Open
Abstract
Mutations in genes encoding nuclear envelope proteins lead to diseases known as nuclear envelopathies, characterized by skeletal muscle and heart abnormalities, such as Emery-Dreifuss muscular dystrophy (EDMD). The tissue-specific role of the nuclear envelope in the etiology of these diseases has not been extensively explored. We previously showed that global deletion of the muscle-specific nuclear envelope protein NET39 in mice leads to neonatal lethality due to skeletal muscle dysfunction. To study the potential role of the Net39 gene in adulthood, we generated a muscle-specific conditional knockout (cKO) of Net39 in mice. cKO mice recapitulated key skeletal muscle features of EDMD, including muscle wasting, impaired muscle contractility, abnormal myonuclear morphology, and DNA damage. The loss of Net39 rendered myoblasts hypersensitive to mechanical stretch, resulting in stretch-induced DNA damage. Net39 was downregulated in a mouse model of congenital myopathy, and restoration of Net39 expression through AAV gene delivery extended life span and ameliorated muscle abnormalities. These findings establish NET39 as a direct contributor to the pathogenesis of EDMD that acts by protecting against mechanical stress and DNA damage.
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Affiliation(s)
- Yichi Zhang
- Department of Molecular Biology
- Hamon Center for Regenerative Science and Medicine
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center
| | - Andres Ramirez-Martinez
- Department of Molecular Biology
- Hamon Center for Regenerative Science and Medicine
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center
| | - Kenian Chen
- Quantitative Biomedical Research Center, Peter O’Donnell Jr. School of Public Health, and
| | - John R. McAnally
- Department of Molecular Biology
- Hamon Center for Regenerative Science and Medicine
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center
| | - Chunyu Cai
- Department of Pathology, University of Texas (UT) Southwestern Medical Center, Dallas, Texas, USA
| | - Mateusz Z. Durbacz
- Department of Molecular Biology
- Hamon Center for Regenerative Science and Medicine
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center
| | - Francesco Chemello
- Department of Molecular Biology
- Hamon Center for Regenerative Science and Medicine
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center
| | - Zhaoning Wang
- Department of Molecular Biology
- Hamon Center for Regenerative Science and Medicine
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center
| | - Lin Xu
- Quantitative Biomedical Research Center, Peter O’Donnell Jr. School of Public Health, and
| | - Rhonda Bassel-Duby
- Department of Molecular Biology
- Hamon Center for Regenerative Science and Medicine
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center
| | - Ning Liu
- Department of Molecular Biology
- Hamon Center for Regenerative Science and Medicine
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center
| | - Eric N. Olson
- Department of Molecular Biology
- Hamon Center for Regenerative Science and Medicine
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center
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3
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Zhang CY, Yang CQ, Chen Q, Liu J, Zhang G, Dong C, Liu XL, Farooq HMU, Zhao SQ, Luo LH, Jiang SF, Niu YB, Yin DC. miR-194-Loaded Gelatin Nanospheres Target MEF2C to Suppress Muscle Atrophy in a Mechanical Unloading Model. Mol Pharm 2021; 18:2959-2973. [PMID: 34189919 DOI: 10.1021/acs.molpharmaceut.1c00121] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Muscle atrophy usually occurs under mechanical unloading, which increases the risk of injury to reduce the functionality of the moving system, while there is still no effective therapy until now. It was found that miR-194 was significantly downregulated in a muscle atrophy model, and its target protein was the myocyte enhancer factor 2C (MEF2C). miR-194 could promote muscle differentiation and also inhibit ubiquitin ligases, thus miR-194 could be used as a nucleic acid drug to treat muscle atrophy, whereas miRNA was unstable in vivo, limiting its application as a therapeutic drug. A gelatin nanosphere (GN) delivery system was applied for the first time to load exogenous miRNA here. Exogenous miR-194 was loaded in GNs and injected into the muscle atrophy model. It demonstrated that the muscle fiber cross-sectional area, in situ muscle contractile properties, and myogenic markers were increased significantly after treatment. It proposed miR-194 loaded in GNs as an effective treatment for muscle atrophy by promoting muscle differentiation and inhibiting ubiquitin ligase activity. Moreover, the developed miRNA delivery system, taking advantage of its tunable composition, degradation rate, and capacity to load various drug molecules with high dosage, is considered a promising platform to achieve precise treatment of muscle atrophy-related diseases.
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Affiliation(s)
- Chen-Yan Zhang
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, P. R. China
| | - Chang-Qing Yang
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, P. R. China
| | - Qiang Chen
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, P. R. China
| | - Jie Liu
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, P. R. China
| | - Ge Zhang
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, P. R. China
| | - Chen Dong
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, P. R. China
| | - Xin-Li Liu
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, P. R. China
| | - Hafiz Muhammad Umer Farooq
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, P. R. China
| | - Shi-Qi Zhao
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, P. R. China
| | - Li-Heng Luo
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, P. R. China
| | - Shan-Feng Jiang
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, P. R. China
| | - Yin-Bo Niu
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, P. R. China
| | - Da-Chuan Yin
- Institute for Special Environmental Biophysics, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, Shaanxi, P. R. China
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4
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Wright CF, Quaife NM, Ramos-Hernández L, Danecek P, Ferla MP, Samocha KE, Kaplanis J, Gardner EJ, Eberhardt RY, Chao KR, Karczewski KJ, Morales J, Gallone G, Balasubramanian M, Banka S, Gompertz L, Kerr B, Kirby A, Lynch SA, Morton JEV, Pinz H, Sansbury FH, Stewart H, Zuccarelli BD, Cook SA, Taylor JC, Juusola J, Retterer K, Firth HV, Hurles ME, Lara-Pezzi E, Barton PJR, Whiffin N. Non-coding region variants upstream of MEF2C cause severe developmental disorder through three distinct loss-of-function mechanisms. Am J Hum Genet 2021; 108:1083-1094. [PMID: 34022131 PMCID: PMC8206381 DOI: 10.1016/j.ajhg.2021.04.025] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/29/2021] [Indexed: 02/08/2023] Open
Abstract
Clinical genetic testing of protein-coding regions identifies a likely causative variant in only around half of developmental disorder (DD) cases. The contribution of regulatory variation in non-coding regions to rare disease, including DD, remains very poorly understood. We screened 9,858 probands from the Deciphering Developmental Disorders (DDD) study for de novo mutations in the 5' untranslated regions (5' UTRs) of genes within which variants have previously been shown to cause DD through a dominant haploinsufficient mechanism. We identified four single-nucleotide variants and two copy-number variants upstream of MEF2C in a total of ten individual probands. We developed multiple bespoke and orthogonal experimental approaches to demonstrate that these variants cause DD through three distinct loss-of-function mechanisms, disrupting transcription, translation, and/or protein function. These non-coding region variants represent 23% of likely diagnoses identified in MEF2C in the DDD cohort, but these would all be missed in standard clinical genetics approaches. Nonetheless, these variants are readily detectable in exome sequence data, with 30.7% of 5' UTR bases across all genes well covered in the DDD dataset. Our analyses show that non-coding variants upstream of genes within which coding variants are known to cause DD are an important cause of severe disease and demonstrate that analyzing 5' UTRs can increase diagnostic yield. We also show how non-coding variants can help inform both the disease-causing mechanism underlying protein-coding variants and dosage tolerance of the gene.
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Affiliation(s)
- Caroline F Wright
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Royal Devon & Exeter Hospital, Exeter EX2 5DW, UK
| | - Nicholas M Quaife
- National Heart & Lung Institute and MRC London Institute of Medical Sciences, Imperial College London, London W12 0NN, UK; Cardiovascular Research Centre, Royal Brompton & Harefield Hospitals NHS Trust, London SW3 6NP, UK
| | - Laura Ramos-Hernández
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain
| | - Petr Danecek
- Human Genetics Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1RQ, UK
| | - Matteo P Ferla
- National Institute for Health Research Oxford Biomedical Research Centre, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Kaitlin E Samocha
- Human Genetics Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1RQ, UK
| | - Joanna Kaplanis
- Human Genetics Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1RQ, UK
| | - Eugene J Gardner
- Human Genetics Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1RQ, UK
| | - Ruth Y Eberhardt
- Human Genetics Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1RQ, UK
| | - Katherine R Chao
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Konrad J Karczewski
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Joannella Morales
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Cambridge CB10 1SD, UK
| | - Giuseppe Gallone
- Human Genetics Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1RQ, UK
| | - Meena Balasubramanian
- Sheffield Clinical Genetics Service, Sheffield Children's NHS Foundation Trust, Sheffield S10 2TH, UK; Academic Unit of Child Health, Department of Oncology & Metabolism, University of Sheffield, Sheffield S10 2TH, UK
| | - Siddharth Banka
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University Hospitals NHS Foundation Trust, Health Innovation Manchester, Manchester M13 9WL, UK; Division of Evolution and Genomic Sciences, School of Biological Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Lianne Gompertz
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University Hospitals NHS Foundation Trust, Health Innovation Manchester, Manchester M13 9WL, UK
| | - Bronwyn Kerr
- Division of Evolution and Genomic Sciences, School of Biological Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Amelia Kirby
- Department of Pediatrics, Wake Forest School of Medicine, Winston-Salem, NC 27101, USA
| | - Sally A Lynch
- UCD Academic Centre on Rare Diseases, School of Medicine and Medical Sciences, University College Dublin, and Clinical Genetics, Temple Street Children's University Hospital, Dublin D01 XD99, Ireland
| | - Jenny E V Morton
- West Midlands Regional Clinical Genetics Service and Birmingham Health Partners, Birmingham Women's and Children's Hospitals NHS Foundation Trust, Birmingham B4 6NH, UK
| | - Hailey Pinz
- Department of Pediatrics, Saint Louis University School of Medicine, Saint Louis, MO 63104, USA
| | - Francis H Sansbury
- All Wales Medical Genomics Service, NHS Wales Cardiff and Vale University Health Board, Institute of Medical Genetics, University Hospital of Wales, Cardiff CF14 4AY, UK
| | - Helen Stewart
- Oxford Centre for Genomic Medicine, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 7LE, UK
| | - Britton D Zuccarelli
- Department of Neurology, University of Kansas School of Medicine-Salina Campus, Salina, KS 67401, USA
| | - Stuart A Cook
- National Heart & Lung Institute and MRC London Institute of Medical Sciences, Imperial College London, London W12 0NN, UK
| | - Jenny C Taylor
- National Institute for Health Research Oxford Biomedical Research Centre, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | | | | | - Helen V Firth
- Human Genetics Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1RQ, UK; East Anglian Medical Genetics Service, Cambridge University Hospitals NHS Foundation Trust, Cambridge CB2 0QQ, UK
| | - Matthew E Hurles
- Human Genetics Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1RQ, UK
| | - Enrique Lara-Pezzi
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), 28029 Madrid, Spain; CIBER de enfermedades CardioVasculares (CIBERCV), 28029 Madrid, Spain
| | - Paul J R Barton
- National Heart & Lung Institute and MRC London Institute of Medical Sciences, Imperial College London, London W12 0NN, UK; Cardiovascular Research Centre, Royal Brompton & Harefield Hospitals NHS Trust, London SW3 6NP, UK
| | - Nicola Whiffin
- Human Genetics Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1RQ, UK; Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK.
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5
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Network-based analysis on genetic variants reveals the immunological mechanism underlying Alzheimer's disease. J Neural Transm (Vienna) 2021; 128:803-816. [PMID: 33909139 DOI: 10.1007/s00702-021-02337-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 04/11/2021] [Indexed: 12/14/2022]
Abstract
Alzheimer's Disease (AD) is a neurodegenerative disorder characterized by the impairment of cognitive function and loss of memory. Previous studies indicate an essential role of immune response in AD, but the detailed mechanisms remain unclear. In this study, we obtained 1664 credible risk variants (CRVs) based on the most significant SNP detected by International Genomics of Alzheimer's Project, from which 99 genes (CRVs-related genes) were identified. Function analysis revealed that these genes were mainly involved in immune response and amyloid-β and its precursor metabolisms, indicating a potential role of immune response in regulating neurobiological processes in the etiology of neurodegenerative disease. Pathway crosstalk analysis revealed the complicated connections between immune-related pathways. Further, we found that the CRVs-related genes showed temporal-specific expression in the thalamus in adolescence developmental period. Cell type-specific expression analysis found that CRVs-related genes might be specifically expressed in brain cells such as astrocytes and oligodendrocytes. Protein-protein interaction network analysis identified the highly interconnected 'hub' genes, all of which were susceptible loci of AD. These results indicated that the CRVs may exert a potential influence in AD by regulating immune response, thalamus development, astrocytes activities, and amyloid-β binding. Our results provided hints for further experimental verification of AD pathophysiology.
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Huang B, Wang J, Zhang X, Xie Z, Wu H, Liu J, Jie Z, Zhao X, Qin A, Fan S, Chen J, Zhao F. Administration of SB239063 Ameliorates Ovariectomy-Induced Bone Loss via Suppressing Osteoclastogenesis in Mice. Front Pharmacol 2019; 10:900. [PMID: 31474861 PMCID: PMC6704231 DOI: 10.3389/fphar.2019.00900] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 07/17/2019] [Indexed: 11/13/2022] Open
Abstract
Activation of osteoclast formation and function is crucial for the development of osteolytic diseases such as osteoporosis. RANKL (receptor activator of nuclear factor-κB ligand) activates NF-κB (nuclear factor κB), MAPK (mitogen-activated protein kinase), and NFATc1 (nuclear factor of activated T-cells, cytoplasmic 1) signaling pathways to induce osteoclastogenesis. In this study, we demonstrated that SB239063, a p38-specific inhibitor, suppressed osteoclastogenesis and bone resorption via inhibiting phosphorylation of MEF2C (myocyte enhancer factor 2C) and subsequently leading to MEF2C degradation by ubiquitination. Knockdown of MEF2C impaired osteoclast formation due to decreased c-Fos expression. Furthermore, MEF2C can directly bind to the promoter region of c-Fos to initiate its transcription. Interestingly, overexpression of either MEF2C or c-Fos can partially rescue the inhibitory effect of SB239063 on osteoclastogenesis. In addition, in vivo data proved that SB239063 also played a preventive role in both LPS (lipopolysaccharide)- and OVX (ovariectomy)-induced bone loss in mice. In conclusion, our results show that SB239063 can be a potential therapy for osteolytic diseases, and a novel p38/MEF2C/c-Fos axis is essential for osteoclastogenesis.
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Affiliation(s)
- Bao Huang
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, China
| | - Jiasheng Wang
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, China
| | - Xuyang Zhang
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, China
| | - Ziang Xie
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, China
| | - Hao Wu
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, China
| | - Junhui Liu
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, China
| | - Zhiwei Jie
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, China
| | - Xiangde Zhao
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, China
| | - An Qin
- Department of Orthopaedics, Shanghai Key Laboratory of Orthopaedic Implant, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shunwu Fan
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, China
| | - Jian Chen
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, China
| | - Fengdong Zhao
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, China
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7
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Dodge-Kafka K, Gildart M, Tokarski K, Kapiloff MS. mAKAPβ signalosomes - A nodal regulator of gene transcription associated with pathological cardiac remodeling. Cell Signal 2019; 63:109357. [PMID: 31299211 PMCID: PMC7197268 DOI: 10.1016/j.cellsig.2019.109357] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 07/01/2019] [Accepted: 07/05/2019] [Indexed: 12/14/2022]
Abstract
Striated myocytes compose about half of the cells of the heart, while contributing the majority of the heart's mass and volume. In response to increased demands for pumping power, including in diseases of pressure and volume overload, the contractile myocytes undergo non-mitotic growth, resulting in increased heart mass, i.e. cardiac hypertrophy. Myocyte hypertrophy is induced by a change in the gene expression program driven by the altered activity of transcription factors and co-repressor and co-activator chromatin-associated proteins. These gene regulatory proteins are subject to diverse post-translational modifications and serve as nuclear effectors for intracellular signal transduction pathways, including those controlled by cyclic nucleotides and calcium ion. Scaffold proteins contribute to the underlying architecture of intracellular signaling networks by targeting signaling enzymes to discrete intracellular compartments, providing specificity to the regulation of downstream effectors, including those regulating gene expression. Muscle A-kinase anchoring protein β (mAKAPβ) is a well-characterized scaffold protein that contributes to the regulation of pathological cardiac hypertrophy. In this review, we discuss the mechanisms how this prototypical scaffold protein organizes signalosomes responsible for the regulation of class IIa histone deacetylases and cardiac transcription factors such as NFAT, MEF2, and HIF-1α, as well as how this signalosome represents a novel therapeutic target for the prevention or treatment of heart failure.
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Affiliation(s)
- Kimberly Dodge-Kafka
- Calhoun Center for Cardiology, Cardiac Signal Transduction and Cellular Biology Laboratory, University of Connecticut Health Center, Farmington, CT, USA.
| | - Moriah Gildart
- Calhoun Center for Cardiology, Cardiac Signal Transduction and Cellular Biology Laboratory, University of Connecticut Health Center, Farmington, CT, USA
| | - Kristin Tokarski
- Calhoun Center for Cardiology, Cardiac Signal Transduction and Cellular Biology Laboratory, University of Connecticut Health Center, Farmington, CT, USA
| | - Michael S Kapiloff
- Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA, USA
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8
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Tóth AD, Schell R, Lévay M, Vettel C, Theis P, Haslinger C, Alban F, Werhahn S, Frischbier L, Krebs-Haupenthal J, Thomas D, Gröne HJ, Avkiran M, Katus HA, Wieland T, Backs J. Inflammation leads through PGE/EP 3 signaling to HDAC5/MEF2-dependent transcription in cardiac myocytes. EMBO Mol Med 2019; 10:emmm.201708536. [PMID: 29907596 PMCID: PMC6034133 DOI: 10.15252/emmm.201708536] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The myocyte enhancer factor 2 (MEF2) regulates transcription in cardiac myocytes and adverse remodeling of adult hearts. Activators of G protein-coupled receptors (GPCRs) have been reported to activate MEF2, but a comprehensive analysis of GPCR activators that regulate MEF2 has to our knowledge not been performed. Here, we tested several GPCR agonists regarding their ability to activate a MEF2 reporter in neonatal rat ventricular myocytes. The inflammatory mediator prostaglandin E2 (PGE2) strongly activated MEF2. Using pharmacological and protein-based inhibitors, we demonstrated that PGE2 regulates MEF2 via the EP3 receptor, the βγ subunit of Gi/o protein and two concomitantly activated downstream pathways. The first consists of Tiam1, Rac1, and its effector p21-activated kinase 2, the second of protein kinase D. Both pathways converge on and inactivate histone deacetylase 5 (HDAC5) and thereby de-repress MEF2. In vivo, endotoxemia in MEF2-reporter mice induced upregulation of PGE2 and MEF2 activation. Our findings provide an unexpected new link between inflammation and cardiac remodeling by de-repression of MEF2 through HDAC5 inactivation, which has potential implications for new strategies to treat inflammatory cardiomyopathies.
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Affiliation(s)
- András D Tóth
- Department of Molecular Cardiology and Epigenetics, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany.,Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Richard Schell
- Department of Molecular Cardiology and Epigenetics, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany.,Department of Cardiology, Heidelberg University, Heidelberg, Germany
| | - Magdolna Lévay
- DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany.,Experimental Pharmacology, European Center of Angioscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Christiane Vettel
- DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany.,Experimental Pharmacology, European Center of Angioscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Philipp Theis
- Department of Molecular Cardiology and Epigenetics, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany
| | - Clemens Haslinger
- Department of Molecular Cardiology and Epigenetics, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany
| | - Felix Alban
- Department of Molecular Cardiology and Epigenetics, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany
| | - Stefanie Werhahn
- Department of Molecular Cardiology and Epigenetics, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany
| | - Lina Frischbier
- Department of Molecular Cardiology and Epigenetics, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany
| | - Jutta Krebs-Haupenthal
- Department of Molecular Cardiology and Epigenetics, Heidelberg University, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany
| | - Dominique Thomas
- Institute of Clinical Pharmacology, Goethe University Frankfurt, Frankfurt, Germany
| | - Hermann-Josef Gröne
- Department of Cellular and Molecular Pathology, German Cancer Research Center, Heidelberg, Germany
| | - Metin Avkiran
- Cardiovascular Division, King's College London British Heart Foundation Centre of Research Excellence, The Rayne Institute, St Thomas' Hospital, London, UK
| | - Hugo A Katus
- Department of Cardiology, Heidelberg University, Heidelberg, Germany
| | - Thomas Wieland
- DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany.,Experimental Pharmacology, European Center of Angioscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Johannes Backs
- Department of Molecular Cardiology and Epigenetics, Heidelberg University, Heidelberg, Germany .,DZHK (German Centre for Cardiovascular Research), Heidelberg/Mannheim, Germany
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9
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Guo A, Wang Y, Chen B, Wang Y, Yuan J, Zhang L, Hall D, Wu J, Shi Y, Zhu Q, Chen C, Thiel WH, Zhan X, Weiss RM, Zhan F, Musselman CA, Pufall M, Zhu W, Au KF, Hong J, Anderson ME, Grueter CE, Song LS. E-C coupling structural protein junctophilin-2 encodes a stress-adaptive transcription regulator. Science 2018; 362:science.aan3303. [PMID: 30409805 DOI: 10.1126/science.aan3303] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 05/10/2018] [Accepted: 10/24/2018] [Indexed: 11/02/2022]
Abstract
Junctophilin-2 (JP2) is a structural protein required for normal excitation-contraction (E-C) coupling. After cardiac stress, JP2 is cleaved by the calcium ion-dependent protease calpain, which disrupts the E-C coupling ultrastructural machinery and drives heart failure progression. We found that stress-induced proteolysis of JP2 liberates an N-terminal fragment (JP2NT) that translocates to the nucleus, binds to genomic DNA, and controls expression of a spectrum of genes in cardiomyocytes. Transgenic overexpression of JP2NT in mice modifies the transcriptional profile, resulting in attenuated pathological remodeling in response to cardiac stress. Conversely, loss of nuclear JP2NT function accelerates stress-induced development of hypertrophy and heart failure in mutant mice. These data reveal a self-protective mechanism in failing cardiomyocytes that transduce mechanical information (E-C uncoupling) into salutary transcriptional reprogramming in the stressed heart.
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Affiliation(s)
- Ang Guo
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Yihui Wang
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA.,Department of Emergency Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
| | - Biyi Chen
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Yunhao Wang
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Jinxiang Yuan
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Liyang Zhang
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Duane Hall
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Jennifer Wu
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Yun Shi
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Qi Zhu
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA.,Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, Jiangsu 226001, China
| | - Cheng Chen
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA.,Department of Emergency Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
| | - William H Thiel
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Xin Zhan
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Robert M Weiss
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Fenghuang Zhan
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Catherine A Musselman
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Miles Pufall
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Weizhong Zhu
- Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, Jiangsu 226001, China
| | - Kin Fai Au
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Jiang Hong
- Department of Emergency Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
| | - Mark E Anderson
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Chad E Grueter
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA.,Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Long-Sheng Song
- Department of Internal Medicine, Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA. .,Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA.,Iowa City Veterans Affairs Medical Center, Iowa City, IA 52242, USA
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10
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Abstract
Dietary triglyceride (TG) is the most efficient energy substrate. It is processed and stored at substantially lower metabolic cost than is protein or carbohydrate. In fed animals, circulating TGs are preferentially routed for storage to white adipose tissue (WAT) by angiopoietin-like proteins 3 (A3) and 8 (A8). Here, we show that mice lacking A3 and A8 (A3-/-A8-/- mice) have decreased fat mass and a striking increase in temperature (+1 °C) in the fed (but not fasted) state, without alterations in food intake or physical activity. Subcutaneous WAT (WAT-SQ) from these animals had morphologic and metabolic changes characteristic of beiging. O2 consumption rates (OCRs) and expression of genes involved in both fatty acid synthesis and fatty acid oxidation were increased in WAT-SQ of A3-/-A8-/- mice, but not in their epididymal or brown adipose tissue (BAT). The hyperthermic response to feeding was blocked by maintaining A3-/-A8-/- mice at thermoneutrality or by treating with a β3-adrenergic receptor (AR) antagonist. To determine if sympathetic stimulation was sufficient to increase body temperature in A3-/-A8-/- mice, WT and A3-/-A8-/- animals were maintained at thermoneutrality and then treated with a β3-AR agonist; treatment induced hyperthermia in A3-/-A8-/- , but not WT, mice. Antibody-mediated inactivation of both circulating A3 and A8 induced hyperthermia in WT mice. Together, these data indicate that A3 and A8 are essential for efficient storage of dietary TG and that disruption of these genes increases feeding-induced thermogenesis and energy utilization.
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11
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Wei J, Joshi S, Speransky S, Crowley C, Jayathilaka N, Lei X, Wu Y, Gai D, Jain S, Hoosien M, Gao Y, Chen L, Bishopric NH. Reversal of pathological cardiac hypertrophy via the MEF2-coregulator interface. JCI Insight 2017; 2:91068. [PMID: 28878124 DOI: 10.1172/jci.insight.91068] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 07/19/2017] [Indexed: 11/17/2022] Open
Abstract
Cardiac hypertrophy, as a response to hemodynamic stress, is associated with cardiac dysfunction and death, but whether hypertrophy itself represents a pathological process remains unclear. Hypertrophy is driven by changes in myocardial gene expression that require the MEF2 family of DNA-binding transcription factors, as well as the nuclear lysine acetyltransferase p300. Here we used genetic and small-molecule probes to determine the effects of preventing MEF2 acetylation on cardiac adaptation to stress. Both nonacetylatable MEF2 mutants and 8MI, a molecule designed to interfere with MEF2-coregulator binding, prevented hypertrophy in cultured cardiac myocytes. 8MI prevented cardiac hypertrophy in 3 distinct stress models, and reversed established hypertrophy in vivo, associated with normalization of myocardial structure and function. The effects of 8MI were reversible, and did not prevent training effects of swimming. Mechanistically, 8MI blocked stress-induced MEF2 acetylation, nuclear export of class II histone deacetylases HDAC4 and -5, and p300 induction, without impeding HDAC4 phosphorylation. Correspondingly, 8MI transformed the transcriptional response to pressure overload, normalizing almost all 232 genes dysregulated by hemodynamic stress. We conclude that MEF2 acetylation is required for development and maintenance of pathological cardiac hypertrophy, and that blocking MEF2 acetylation can permit recovery from hypertrophy without impairing physiologic adaptation.
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Affiliation(s)
| | - Shaurya Joshi
- Department of Molecular and Cellular Pharmacology, and
| | | | | | - Nimanthi Jayathilaka
- Departments of Biological Sciences and Chemistry, University of Southern California, Los Angeles, California, USA
| | - Xiao Lei
- Departments of Biological Sciences and Chemistry, University of Southern California, Los Angeles, California, USA
| | - Yongqing Wu
- Departments of Biological Sciences and Chemistry, University of Southern California, Los Angeles, California, USA
| | - David Gai
- Departments of Biological Sciences and Chemistry, University of Southern California, Los Angeles, California, USA
| | - Sumit Jain
- Department of Molecular and Cellular Pharmacology, and
| | | | | | - Lin Chen
- Departments of Biological Sciences and Chemistry, University of Southern California, Los Angeles, California, USA
| | - Nanette H Bishopric
- Department of Medicine.,Department of Molecular and Cellular Pharmacology, and.,Department of Pediatrics, University of Miami Miller School of Medicine, Miami, Florida, USA
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12
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Dong C, Yang XZ, Zhang CY, Liu YY, Zhou RB, Cheng QD, Yan EK, Yin DC. Myocyte enhancer factor 2C and its directly-interacting proteins: A review. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2017; 126:22-30. [DOI: 10.1016/j.pbiomolbio.2017.02.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 11/24/2016] [Accepted: 02/01/2017] [Indexed: 11/27/2022]
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13
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Heart Failure and MEF2 Transcriptome Dynamics in Response to β-Blockers. Sci Rep 2017; 7:4476. [PMID: 28667250 PMCID: PMC5493616 DOI: 10.1038/s41598-017-04762-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 05/19/2017] [Indexed: 01/12/2023] Open
Abstract
Myocyte Enhancer Factor 2 (MEF2) mediates cardiac remodelling in heart failure (HF) and is also a target of β-adrenergic signalling, a front-line treatment for HF. We identified global gene transcription networks involved in HF with and without β-blocker treatment. Experimental HF by transverse aortic constriction (TAC) in a MEF2 “sensor” mouse model (6 weeks) was followed by four weeks of β-blockade with Atenolol (AT) or Solvent (Sol) treatment. Transcriptome analysis (RNA-seq) from left ventricular RNA samples and MEF2A depleted cardiomyocytes was performed. AT treatment resulted in an overall improvement in cardiac function of TAC mice and repression of MEF2 activity. RNA-seq identified 65 differentially expressed genes (DEGs) due to TAC treatment with enriched GO clusters including the inflammatory system, cell migration and apoptosis. These genes were mapped against DEGs in cardiomyocytes in which MEF2A expression was suppressed. Of the 65 TAC mediated DEGs, AT reversed the expression of 28 mRNAs. Rarres2 was identified as a novel MEF2 target gene that is upregulated with TAC in vivo and isoproterenol treatment in vitro which may have implications in cardiomyocyte apoptosis and hypertrophy. These studies identify a cohort of genes with vast potential for disease diagnosis and therapeutic intervention in heart failure.
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14
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Amara CS, Fabritius C, Houben A, Wolff LI, Hartmann C. CaMKII Signaling Stimulates Mef2c Activity In Vitro but Only Minimally Affects Murine Long Bone Development in vivo. Front Cell Dev Biol 2017; 5:20. [PMID: 28361052 PMCID: PMC5352711 DOI: 10.3389/fcell.2017.00020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 03/02/2017] [Indexed: 01/17/2023] Open
Abstract
The long bones of vertebrate limbs form by endochondral ossification, whereby mesenchymal cells differentiate into chondrogenic progenitors, which then differentiate into chondrocytes. Chondrocytes undergo further differentiation from proliferating to prehypertrophic, and finally to hypertrophic chondrocytes. Several signaling pathways and transcription factors regulate this process. Previously, we and others have shown in chicken that overexpression of an activated form of Calcium/calmodulin-dependent kinase II (CaMKII) results in ectopic chondrocyte maturation. Here, we show that this is not the case in the mouse. Although, in vitro Mef2c activity was upregulated by about 55-fold in response to expression of an activated form of CaMKII (DACaMKII), transgenic mice that expressed a dominant-active form of CaMKII under the control of the Col2a1 regulatory elements display only a very transient and mild phenotype. Here, only the onset of chondrocyte hypertrophy at E12.5 is accelerated. It is also this early step in chondrocyte differentiation that is temporarily delayed around E13.5 in transgenic mice expressing the peptide inhibitor CaM-KIIN from rat (rKIIN) under the control of the Col2a1 regulatory elements. Yet, ultimately DACaMKII, as well as rKIIN transgenic mice are born with completely normal skeletal elements with regard to their length and growth plate organization. Hence, our in vivo analysis suggests that CaMKII signaling plays a minor role in chondrocyte maturation in mice.
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Affiliation(s)
- Chandra S Amara
- Department Bone and Skeletal Research, Medical Faculty of the University of Münster (WWU), Institute of Experimental Musculoskeletal Medicine Münster, Germany
| | - Christine Fabritius
- Department Bone and Skeletal Research, Medical Faculty of the University of Münster (WWU), Institute of Experimental Musculoskeletal Medicine Münster, Germany
| | - Astrid Houben
- Department Bone and Skeletal Research, Medical Faculty of the University of Münster (WWU), Institute of Experimental Musculoskeletal Medicine Münster, Germany
| | - Lena I Wolff
- Department Bone and Skeletal Research, Medical Faculty of the University of Münster (WWU), Institute of Experimental Musculoskeletal Medicine Münster, Germany
| | - Christine Hartmann
- Department Bone and Skeletal Research, Medical Faculty of the University of Münster (WWU), Institute of Experimental Musculoskeletal Medicine Münster, Germany
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15
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Desjardins CA, Naya FJ. The Function of the MEF2 Family of Transcription Factors in Cardiac Development, Cardiogenomics, and Direct Reprogramming. J Cardiovasc Dev Dis 2016; 3. [PMID: 27630998 PMCID: PMC5019174 DOI: 10.3390/jcdd3030026] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Proper formation of the mammalian heart requires precise spatiotemporal transcriptional regulation of gene programs in cardiomyocytes. Sophisticated regulatory networks have evolved to not only integrate the activities of distinct transcription factors to control tissue-specific gene programs but also, in many instances, to incorporate multiple members within these transcription factor families to ensure accuracy and specificity in the system. Unsurprisingly, perturbations in this elaborate transcriptional circuitry can lead to severe cardiac abnormalities. Myocyte enhancer factor–2 (MEF2) transcription factor belongs to the evolutionarily conserved cardiac gene regulatory network. Given its central role in muscle gene regulation and its evolutionary conservation, MEF2 is considered one of only a few core cardiac transcription factors. In addition to its firmly established role as a differentiation factor, MEF2 regulates wide variety of, sometimes antagonistic, cellular processes such as cell survival and death. Vertebrate genomes encode multiple MEF2 family members thereby expanding the transcriptional potential of this core transcription factor in the heart. This review highlights the requirement of the MEF2 family and their orthologs in cardiac development in diverse animal model systems. Furthermore, we describe the recently characterized role of MEF2 in direct reprogramming and genome-wide cardiomyocyte gene regulation. A thorough understanding of the regulatory functions of the MEF2 family in cardiac development and cardiogenomics is required in order to develop effective therapeutic strategies to repair the diseased heart.
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16
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Cardoso AC, Pereira AHM, Ambrosio ALB, Consonni SR, Rocha de Oliveira R, Bajgelman MC, Dias SMG, Franchini KG. FAK Forms a Complex with MEF2 to Couple Biomechanical Signaling to Transcription in Cardiomyocytes. Structure 2016; 24:1301-1310. [PMID: 27427476 DOI: 10.1016/j.str.2016.06.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 05/06/2016] [Accepted: 06/04/2016] [Indexed: 11/27/2022]
Abstract
Focal adhesion kinase (FAK) has emerged as a mediator of mechanotransduction in cardiomyocytes, regulating gene expression during hypertrophic remodeling. However, how FAK signaling is relayed onward to the nucleus is unclear. Here, we show that FAK interacts with and regulates myocyte enhancer factor 2 (MEF2), a master cardiac transcriptional regulator. In cardiomyocytes exposed to biomechanical stimulation, FAK accumulates in the nucleus, binds to and upregulates the transcriptional activity of MEF2 through an interaction with the FAK focal adhesion targeting (FAT) domain. In the crystal structure (2.9 Å resolution), FAT binds to a stably folded groove in the MEF2 dimer, known to interact with regulatory cofactors. FAK cooperates with MEF2 to enhance the expression of Jun in cardiomyocytes, an important component of hypertrophic response to mechanical stress. These findings underscore a connection between the mechanotransduction involving FAK and transcriptional regulation by MEF2, with potential relevance to the pathogenesis of cardiac disease.
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Affiliation(s)
- Alisson Campos Cardoso
- Brazilian National Laboratory for Biosciences, Center for Research in Energy and Materials, Campinas, São Paulo 13084-971, Brazil
| | - Ana Helena Macedo Pereira
- Brazilian National Laboratory for Biosciences, Center for Research in Energy and Materials, Campinas, São Paulo 13084-971, Brazil
| | - Andre Luis Berteli Ambrosio
- Brazilian National Laboratory for Biosciences, Center for Research in Energy and Materials, Campinas, São Paulo 13084-971, Brazil
| | - Silvio Roberto Consonni
- Brazilian National Laboratory for Biosciences, Center for Research in Energy and Materials, Campinas, São Paulo 13084-971, Brazil
| | - Renata Rocha de Oliveira
- Brazilian National Laboratory for Biosciences, Center for Research in Energy and Materials, Campinas, São Paulo 13084-971, Brazil
| | - Marcio Chain Bajgelman
- Brazilian National Laboratory for Biosciences, Center for Research in Energy and Materials, Campinas, São Paulo 13084-971, Brazil
| | - Sandra Martha Gomes Dias
- Brazilian National Laboratory for Biosciences, Center for Research in Energy and Materials, Campinas, São Paulo 13084-971, Brazil
| | - Kleber Gomes Franchini
- Brazilian National Laboratory for Biosciences, Center for Research in Energy and Materials, Campinas, São Paulo 13084-971, Brazil; Department of Internal Medicine, School of Medicine, University of Campinas, Campinas, São Paulo 13081-970, Brazil.
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17
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Abstract
Cardiac remodeling is regulated by an extensive intracellular signal transduction network. Each of the many signaling pathways in this network contributes uniquely to the control of cellular adaptation. In the last few years, it has become apparent that multimolecular signaling complexes or "signalosomes" are important for fidelity in intracellular signaling and for mediating crosstalk between the different signaling pathways. These complexes integrate upstream signals and control downstream effectors. In the cardiac myocyte, the protein mAKAPβ serves as a scaffold for a large signalosome that is responsive to cAMP, calcium, hypoxia, and mitogen-activated protein kinase signaling. The main function of mAKAPβ signalosomes is to modulate stress-related gene expression regulated by the transcription factors NFATc, MEF2, and HIF-1α and type II histone deacetylases that control pathological cardiac hypertrophy.
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18
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Hashemi S, Salma J, Wales S, McDermott JC. Pro-survival function of MEF2 in cardiomyocytes is enhanced by β-blockers. Cell Death Discov 2015; 1:15019. [PMID: 27551452 PMCID: PMC4979494 DOI: 10.1038/cddiscovery.2015.19] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Revised: 07/10/2015] [Accepted: 07/13/2015] [Indexed: 12/18/2022] Open
Abstract
β1-Adrenergic receptor (β1-AR) stimulation increases apoptosis in cardiomyocytes through activation of cAMP/protein kinase A (PKA) signaling. The myocyte enhancer factor 2 (MEF2) proteins function as important regulators of myocardial gene expression. Previously, we reported that PKA signaling directly represses MEF2 activity. We determined whether (a) MEF2 has a pro-survival function in cardiomyocytes, and (b) whether β-adrenergic/PKA signaling modulates MEF2 function in cardiomyocytes. Initially, we observed that siRNA-mediated gene silencing of MEF2 induces cardiomyocyte apoptosis as indicated by flow cytometry. β1-AR activation by isoproterenol represses MEF2 activity and promotes apoptosis in cultured neonatal cardiomyocytes. Importantly, β1-AR mediated apoptosis was abrogated in cardiomyocytes expressing a PKA-resistant form of MEF2D (S121/190A). We also observed that a β1-blocker, Atenolol, antagonizes isoproterenol-induced apoptosis while concomitantly enhancing MEF2 transcriptional activity. β-AR stimulation modulated MEF2 cellular localization in cardiomyocytes and this effect was reversed by β-blocker treatment. Furthermore, Kruppel-like factor 6, a MEF2 target gene in the heart, functions as a downstream pro-survival factor in cardiomyocytes. Collectively, these data indicate that (a) MEF2 has an important pro-survival role in cardiomyocytes, and (b) β-adrenergic signaling antagonizes the pro-survival function of MEF2 in cardiomyocytes and β-blockers promote it. These observations have important clinical implications that may contribute to novel strategies for preventing cardiomyocyte apoptosis associated with heart pathology.
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Affiliation(s)
- S Hashemi
- Department of Biology, York University, Toronto, Canada; Muscle Health Research Centre (MHRC), York University, Toronto, Canada; Centre for Research in Biomolecular Interactions (CRBI), York University, Toronto, Canada
| | - J Salma
- Department of Biology, York University, Toronto, Canada; Muscle Health Research Centre (MHRC), York University, Toronto, Canada; Centre for Research in Biomolecular Interactions (CRBI), York University, Toronto, Canada
| | - S Wales
- Department of Biology, York University, Toronto, Canada; Muscle Health Research Centre (MHRC), York University, Toronto, Canada; Centre for Research in Biomolecular Interactions (CRBI), York University, Toronto, Canada
| | - J C McDermott
- Department of Biology, York University, Toronto, Canada; Muscle Health Research Centre (MHRC), York University, Toronto, Canada; Centre for Research in Biomolecular Interactions (CRBI), York University, Toronto, Canada; Centre for Research in Mass Spectrometry (CRMS), York University, Toronto, Canada
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19
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Clark AL, Naya FJ. MicroRNAs in the Myocyte Enhancer Factor 2 (MEF2)-regulated Gtl2-Dio3 Noncoding RNA Locus Promote Cardiomyocyte Proliferation by Targeting the Transcriptional Coactivator Cited2. J Biol Chem 2015; 290:23162-72. [PMID: 26240138 DOI: 10.1074/jbc.m115.672659] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Indexed: 01/04/2023] Open
Abstract
Understanding cell cycle regulation in postmitotic cardiomyocytes may lead to new therapeutic approaches to regenerate damaged cardiac tissue. We have demonstrated previously that microRNAs encoded by the Gtl2-Dio3 noncoding RNA locus function downstream of the MEF2A transcription factor in skeletal muscle regeneration. We have also reported expression of these miRNAs in the heart. Here we investigated the role of two Gtl2-Dio3 miRNAs, miR-410 and miR-495, in cardiac muscle. Overexpression of miR-410 and miR-495 robustly stimulated cardiomyocyte DNA synthesis and proliferation. Interestingly, unlike our findings in skeletal muscle, these miRNAs did not modulate the activity of the WNT signaling pathway. Instead, these miRNAs targeted Cited2, a coactivator required for proper cardiac development. Consistent with miR-410 and miR-495 overexpression, siRNA knockdown of Cited2 in neonatal cardiomyocytes resulted in robust proliferation. This phenotype was associated with reduced expression of Cdkn1c/p57/Kip2, a cell cycle inhibitor, and increased expression of VEGFA, a growth factor with proliferation-promoting effects. Therefore, miR-410 and miR-495 are among a growing number of miRNAs that have the ability to potently stimulate neonatal cardiomyocyte proliferation.
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Affiliation(s)
- Amanda L Clark
- From the Department of Biology, Program in Cell and Molecular Biology, Boston University, Boston, Massachusetts 02215
| | - Francisco J Naya
- From the Department of Biology, Program in Cell and Molecular Biology, Boston University, Boston, Massachusetts 02215
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20
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Dadson K, Turdi S, Hashemi S, Zhao J, Polidovitch N, Beca S, Backx PH, McDermott JC, Sweeney G. Adiponectin is required for cardiac MEF2 activation during pressure overload induced hypertrophy. J Mol Cell Cardiol 2015. [PMID: 26196305 DOI: 10.1016/j.yjmcc.2015.06.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cardiomyocyte (CM) hypertrophy and increased heart mass in response to pressure overload are associated with hyper-activation of the myocyte enhancer factor-2 (MEF2) family of transcriptional regulators, and concomitant initiation of the fetal gene program. Adiponectin, an adipokine that is reduced in individuals with obesity and diabetes, has been characterized both as a negative regulator or permissive factor in cardiac hypertrophy. We therefore sought to analyze temporal regulation of MEF2 activity in response to pressure overload (PO) and changes in adiponectin status. To address this we crossed a well characterized transgenic MEF2 "sensor" mouse (MEF2-lacZ) with adiponectin null mice (Ad-KO) to create compound MEF2 lacZ/Ad-KO mice. Initially, we established that transverse aortic banding induced PO in wild-type (WT) mice increased heart mass and CM hypertrophy from 1 to 4weeks following surgery, indicated by increased CM diameter and heart weight/tibia length ratio. This was associated with cardiac dysfunction determined by echocardiography. Hypertrophic changes and dysfunction were observed in Ad-KO mice 4weeks following surgery. MEF2 lacZ activity and endogenous ANF mRNA levels, used as indicators of hypertrophic gene activation, were both robustly increased in WT mice after MTAB but attenuated in the Ad-KO background. Furthermore, activation of the pro-hypertrophic molecule p38 was increased following MTAB surgery in WT mice, but not in Ad-KO animals, and treatment of primary isolated CM with recombinant adiponectin induced p38 phosphorylation in a time dependent manner. Adiponectin also increased MEF2 activation in primary cardiomyocytes, an effect attenuated by p38 MAPK inhibition. In conclusion, our data indicate that robust hypertrophic MEF2 activation in the heart in vivo requires a background of adiponectin signaling and that adiponectin signaling in primary isolated CM directly enhances MEF2 activity through activation of p38 MAPK. We conclude that adiponectin is required for full induction of cardiomyocyte MEF2 activation, thus contributing to the myocardial hypertrophic gene expression program in response to PO.
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Affiliation(s)
- Keith Dadson
- Department of Biology, York University, Toronto, Canada
| | - Subat Turdi
- Department of Biology, York University, Toronto, Canada
| | - Sarah Hashemi
- Department of Biology, York University, Toronto, Canada
| | | | - Nazar Polidovitch
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Sanja Beca
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Peter H Backx
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada; Department of Medicine, University of Toronto, Toronto, Ontario, Canada; Peter Munk Cardiac Centre and the Division of Cardiology, University Health Network,Toronto, Ontario, Canada
| | | | - Gary Sweeney
- Department of Biology, York University, Toronto, Canada.
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21
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EGR1 Functions as a Potent Repressor of MEF2 Transcriptional Activity. PLoS One 2015; 10:e0127641. [PMID: 26011708 PMCID: PMC4444265 DOI: 10.1371/journal.pone.0127641] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 04/17/2015] [Indexed: 11/19/2022] Open
Abstract
The myocyte enhancer factor 2 (MEF2) transcription factor requires interactions with co-factors for precise regulation of its target genes. Our lab previously reported that the mammalian MEF2A isoform regulates the cardiomyocyte costamere, a critical muscle-specific focal adhesion complex involved in contractility, through its transcriptional control of genes encoding proteins localized to this cytoskeletal structure. To further dissect the transcriptional mechanisms of costamere gene regulation and identify potential co-regulators of MEF2A, a bioinformatics analysis of transcription factor binding sites was performed using the proximal promoter regions of selected costamere genes. One of these predicted sites belongs to the early growth response (EGR) transcription factor family. The EGR1 isoform has been shown to be involved in a number of pathways in cardiovascular homeostasis and disease, making it an intriguing candidate MEF2 coregulator to further characterize. Here, we demonstrate that EGR1 interacts with MEF2A and is a potent and specific repressor of MEF2 transcriptional activity. Furthermore, we show that costamere gene expression in cardiomyocytes is dependent on EGR1 transcriptional activity. This study identifies a mechanism by which MEF2 activity can be modulated to ensure that costamere gene expression is maintained at levels commensurate with cardiomyocyte contractile activity.
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22
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Wein MN, Spatz J, Nishimori S, Doench J, Root D, Babij P, Nagano K, Baron R, Brooks D, Bouxsein M, Pajevic PD, Kronenberg HM. HDAC5 controls MEF2C-driven sclerostin expression in osteocytes. J Bone Miner Res 2015; 30:400-11. [PMID: 25271055 PMCID: PMC4342334 DOI: 10.1002/jbmr.2381] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Revised: 09/11/2014] [Accepted: 09/25/2014] [Indexed: 01/20/2023]
Abstract
Osteocytes secrete paracrine factors that regulate the balance between bone formation and destruction. Among these molecules, sclerostin (encoded by the gene SOST) inhibits osteoblastic bone formation and is an osteoporosis drug target. The molecular mechanisms underlying SOST expression remain largely unexplored. Here, we report that histone deacetylase 5 (HDAC5) negatively regulates sclerostin levels in osteocytes in vitro and in vivo. HDAC5 shRNA increases, whereas HDAC5 overexpression decreases SOST expression in the novel murine Ocy454 osteocytic cell line. HDAC5 knockout mice show increased levels of SOST mRNA, more sclerostin-positive osteocytes, decreased Wnt activity, low trabecular bone density, and reduced bone formation by osteoblasts. In osteocytes, HDAC5 binds and inhibits the function of MEF2C, a crucial transcription factor for SOST expression. Using chromatin immunoprecipitation, we have mapped endogenous MEF2C binding in the SOST gene to a distal intergenic enhancer 45 kB downstream from the transcription start site. HDAC5 deficiency increases SOST enhancer MEF2C chromatin association and H3K27 acetylation and decreases recruitment of corepressors NCoR and HDAC3. HDAC5 associates with and regulates the transcriptional activity of this enhancer, suggesting direct regulation of SOST gene expression by HDAC5 in osteocytes. Finally, increased sclerostin production achieved by HDAC5 shRNA is abrogated by simultaneous knockdown of MEF2C, indicating that MEF2C is a major target of HDAC5 in osteocytes.
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Affiliation(s)
- Marc N. Wein
- Endocrine Unit, Massachusetts General Hospital, Boston, MA 02114
| | - Jordan Spatz
- Endocrine Unit, Massachusetts General Hospital, Boston, MA 02114
- Harvard–Massachusetts Institute of Technology (MIT) Division of Health Sciences and Technology (HST), Bioastronautics Program, Cambridge, MA, 02139
- Center for Advanced Orthopaedic Studies, BIDMC, Boston, MA, 02215
| | | | - John Doench
- Broad Institute of MIT and Harvard, Cambridge, MA 02142
| | - David Root
- Broad Institute of MIT and Harvard, Cambridge, MA 02142
| | - Philip Babij
- Department of Metabolic Disorders, One Amgen Center Drive, Thousand Oaks, CA 91320
| | | | - Roland Baron
- Harvard School of Dental Medicine, Boston, MA 02115
| | - Daniel Brooks
- Endocrine Unit, Massachusetts General Hospital, Boston, MA 02114
- Center for Advanced Orthopaedic Studies, BIDMC, Boston, MA, 02215
| | - Mary Bouxsein
- Endocrine Unit, Massachusetts General Hospital, Boston, MA 02114
- Center for Advanced Orthopaedic Studies, BIDMC, Boston, MA, 02215
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23
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Anderson CM, Hu J, Barnes RM, Heidt AB, Cornelissen I, Black BL. Myocyte enhancer factor 2C function in skeletal muscle is required for normal growth and glucose metabolism in mice. Skelet Muscle 2015; 5:7. [PMID: 25789156 PMCID: PMC4364460 DOI: 10.1186/s13395-015-0031-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 01/28/2015] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Skeletal muscle is the most abundant tissue in the body and is a major source of total energy expenditure in mammals. Skeletal muscle consists of fast and slow fiber types, which differ in their energy usage, contractile speed, and force generation. Although skeletal muscle plays a major role in whole body metabolism, the transcription factors controlling metabolic function in muscle remain incompletely understood. Members of the myocyte enhancer factor 2 (MEF2) family of transcription factors play crucial roles in skeletal muscle development and function. MEF2C is expressed in skeletal muscle during development and postnatally and is known to play roles in sarcomeric gene expression, fiber type control, and regulation of metabolic genes. METHODS We generated mice lacking Mef2c exclusively in skeletal muscle using a conditional knockout approach and conducted a detailed phenotypic analysis. RESULTS Mice lacking Mef2c in skeletal muscle on an outbred background are viable and grow to adulthood, but they are significantly smaller in overall body size compared to control mice and have significantly fewer slow fibers. When exercised in a voluntary wheel running assay, Mef2c skeletal muscle knockout mice aberrantly accumulate glycogen in their muscle, suggesting an impairment in normal glucose homeostasis. Consistent with this notion, Mef2c skeletal muscle knockout mice exhibit accelerated blood glucose clearance compared to control mice. CONCLUSIONS These findings demonstrate that MEF2C function in skeletal muscle is important for metabolic homeostasis and control of overall body size.
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Affiliation(s)
- Courtney M Anderson
- Cardiovascular Research Institute, University of California San Francisco, 555 Mission Bay Blvd, South, MC 3120, San Francisco, CA 94158-2517 USA
| | - Jianxin Hu
- Cardiovascular Research Institute, University of California San Francisco, 555 Mission Bay Blvd, South, MC 3120, San Francisco, CA 94158-2517 USA
| | - Ralston M Barnes
- Cardiovascular Research Institute, University of California San Francisco, 555 Mission Bay Blvd, South, MC 3120, San Francisco, CA 94158-2517 USA
| | - Analeah B Heidt
- Cardiovascular Research Institute, University of California San Francisco, 555 Mission Bay Blvd, South, MC 3120, San Francisco, CA 94158-2517 USA
| | - Ivo Cornelissen
- Cardiovascular Research Institute, University of California San Francisco, 555 Mission Bay Blvd, South, MC 3120, San Francisco, CA 94158-2517 USA
| | - Brian L Black
- Cardiovascular Research Institute, University of California San Francisco, 555 Mission Bay Blvd, South, MC 3120, San Francisco, CA 94158-2517 USA ; Department of Biochemistry and Biophysics, University of California San Francisco, 555 Mission Bay Blvd, South, MC 3120, San Francisco, CA 94158-2517 USA
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24
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Wales S, Hashemi S, Blais A, McDermott JC. Global MEF2 target gene analysis in cardiac and skeletal muscle reveals novel regulation of DUSP6 by p38MAPK-MEF2 signaling. Nucleic Acids Res 2014; 42:11349-62. [PMID: 25217591 PMCID: PMC4191398 DOI: 10.1093/nar/gku813] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
MEF2 plays a profound role in the regulation of transcription in cardiac and skeletal muscle lineages. To define the overlapping and unique MEF2A genomic targets, we utilized ChIP-exo analysis of cardiomyocytes and skeletal myoblasts. Of the 2783 and 1648 MEF2A binding peaks in skeletal myoblasts and cardiomyocytes, respectively, 294 common binding sites were identified. Genomic targets were compared to differentially expressed genes in RNA-seq analysis of MEF2A depleted myogenic cells, revealing two prominent genetic networks. Genes largely associated with muscle development were down-regulated by loss of MEF2A while up-regulated genes reveal a previously unrecognized function of MEF2A in suppressing growth/proliferative genes. Several up-regulated (Tprg, Mctp2, Kitl, Prrx1, Dusp6) and down-regulated (Atp1a2, Hspb7, Tmem182, Sorbs2, Lmod3) MEF2A target genes were chosen for further investigation. Interestingly, siRNA targeting of the MEF2A/D heterodimer revealed a somewhat divergent role in the regulation of Dusp6, a MAPK phosphatase, in cardiac and skeletal myogenic lineages. Furthermore, MEF2D functions as a p38MAPK-dependent repressor of Dusp6 in myoblasts. These data illustrate that MEF2 orchestrates both common and non-overlapping programs of signal-dependent gene expression in skeletal and cardiac muscle lineages.
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Affiliation(s)
- Stephanie Wales
- Department of Biology, York University, 4700 Keele Street Toronto, Ontario, M3J 1P3 Canada Muscle Health Research Centre (MHRC), York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3 Canada Centre for Research on Biomolecular Interactions (CRBI), 4700 Keele Street, Toronto, Ontario, M3J 1P3 Canada
| | - Sara Hashemi
- Department of Biology, York University, 4700 Keele Street Toronto, Ontario, M3J 1P3 Canada Muscle Health Research Centre (MHRC), York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3 Canada Centre for Research on Biomolecular Interactions (CRBI), 4700 Keele Street, Toronto, Ontario, M3J 1P3 Canada
| | - Alexandre Blais
- Ottawa Institute of Systems Biology, University of Ottawa, Health Sciences Campus, 451 Smyth Road, Ottawa, Ontario, K1H 8M5 Canada
| | - John C McDermott
- Department of Biology, York University, 4700 Keele Street Toronto, Ontario, M3J 1P3 Canada Muscle Health Research Centre (MHRC), York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3 Canada Centre for Research on Biomolecular Interactions (CRBI), 4700 Keele Street, Toronto, Ontario, M3J 1P3 Canada Centre for Research in Mass Spectrometry (CRMS), York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3 Canada
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25
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Kwon IS, Wang W, Xu S, Jin ZG. Histone deacetylase 5 interacts with Krüppel-like factor 2 and inhibits its transcriptional activity in endothelium. Cardiovasc Res 2014; 104:127-37. [PMID: 25096223 DOI: 10.1093/cvr/cvu183] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
AIMS Vascular endothelial dysfunction and inflammation are hallmarks of atherosclerosis. Krüppel-like factor 2 (KLF2) is a key mediator of anti-inflammatory and anti-atherosclerotic properties of the endothelium. However, little is known of the molecular mechanisms for regulating KLF2 transcriptional activation. METHODS AND RESULTS Here, we found that histone deacetylase 5 (HDAC5) associates with KLF2 and represses KLF2 transcriptional activation. HDAC5 resided with KLF2 in the nuclei of human umbilical cord vein endothelial cells (HUVECs). Steady laminar flow attenuated the association of HDAC5 with KLF2 via stimulating HDAC5 phosphorylation-dependent nuclear export in HUVEC. We also mapped the KLF2-HDAC5-interacting domains and found that the N-terminal region of HDAC5 interacts with the C-terminal domain of KLF2. Chromatin immunoprecipitation and luciferase reporter assays showed that HDAC5 through a direct association with KLF2 suppressed KLF2 transcriptional activation. HDAC5 overexpression inhibited KLF2-dependent endothelial nitric oxide synthesis (eNOS) promoter activity in COS7 cell and gene expression in both HUVECs and bovine aortic endothelial cells (BAECs). Conversely, HDAC5 silencing enhanced KLF2 transcription and hence eNOS expression in HUVEC. Moreover, we observed that the level of eNOS protein in the thoracic aorta isolated from HDAC5 knockout mice was higher, whereas expression of pro-inflammatory vascular cell adhesion molecule 1 was lower, compared with those of HDAC5 wild-type mice. CONCLUSIONS We reveal a novel role of HDAC5 in modulating the KLF2 transcriptional activation and eNOS expression. These findings suggest that HDAC5, a binding partner and modulator of KLF2, could be a new therapeutic target to prevent vascular endothelial dysfunction associated with cardiovascular diseases.
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Affiliation(s)
- Il-Sun Kwon
- Aab Cardiovascular Research Institute and Department of Medicine, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Box CVRI, Rochester, NY 14620, USA
| | - Weiye Wang
- Aab Cardiovascular Research Institute and Department of Medicine, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Box CVRI, Rochester, NY 14620, USA
| | - Suowen Xu
- Aab Cardiovascular Research Institute and Department of Medicine, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Box CVRI, Rochester, NY 14620, USA
| | - Zheng-Gen Jin
- Aab Cardiovascular Research Institute and Department of Medicine, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Box CVRI, Rochester, NY 14620, USA
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26
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Clowes C, Boylan MGS, Ridge LA, Barnes E, Wright JA, Hentges KE. The functional diversity of essential genes required for mammalian cardiac development. Genesis 2014; 52:713-37. [PMID: 24866031 PMCID: PMC4141749 DOI: 10.1002/dvg.22794] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 05/22/2014] [Accepted: 05/23/2014] [Indexed: 01/04/2023]
Abstract
Genes required for an organism to develop to maturity (for which no other gene can compensate) are considered essential. The continuing functional annotation of the mouse genome has enabled the identification of many essential genes required for specific developmental processes including cardiac development. Patterns are now emerging regarding the functional nature of genes required at specific points throughout gestation. Essential genes required for development beyond cardiac progenitor cell migration and induction include a small and functionally homogenous group encoding transcription factors, ligands and receptors. Actions of core cardiogenic transcription factors from the Gata, Nkx, Mef, Hand, and Tbx families trigger a marked expansion in the functional diversity of essential genes from midgestation onwards. As the embryo grows in size and complexity, genes required to maintain a functional heartbeat and to provide muscular strength and regulate blood flow are well represented. These essential genes regulate further specialization and polarization of cell types along with proliferative, migratory, adhesive, contractile, and structural processes. The identification of patterns regarding the functional nature of essential genes across numerous developmental systems may aid prediction of further essential genes and those important to development and/or progression of disease. genesis 52:713–737, 2014.
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Affiliation(s)
- Christopher Clowes
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Oxford Road, Manchester, United Kingdom
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27
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Chamberlain AA, Lin M, Lister RL, Maslov AA, Wang Y, Suzuki M, Wu B, Greally JM, Zheng D, Zhou B. DNA methylation is developmentally regulated for genes essential for cardiogenesis. J Am Heart Assoc 2014; 3:e000976. [PMID: 24947998 PMCID: PMC4309105 DOI: 10.1161/jaha.114.000976] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 04/11/2014] [Indexed: 01/13/2023]
Abstract
BACKGROUND DNA methylation is a major epigenetic mechanism altering gene expression in development and disease. However, its role in the regulation of gene expression during heart development is incompletely understood. The aim of this study is to reveal DNA methylation in mouse embryonic hearts and its role in regulating gene expression during heart development. METHODS AND RESULTS We performed the genome-wide DNA methylation profiling of mouse embryonic hearts using methyl-sensitive, tiny fragment enrichment/massively parallel sequencing to determine methylation levels at ACGT sites. The results showed that while global methylation of 1.64 million ACGT sites in developing hearts remains stable between embryonic day (E) 11.5 and E14.5, a small fraction (2901) of them exhibit differential methylation. Gene Ontology analysis revealed that these sites are enriched at genes involved in heart development. Quantitative real-time PCR analysis of 350 genes with differential DNA methylation showed that the expression of 181 genes is developmentally regulated, and 79 genes have correlative changes between methylation and expression, including hyaluronan synthase 2 (Has2). Required for heart valve formation, Has2 expression in the developing heart valves is downregulated at E14.5, accompanied with increased DNA methylation in its enhancer. Genetic knockout further showed that the downregulation of Has2 expression is dependent on DNA methyltransferase 3b, which is co-expressed with Has2 in the forming heart valve region, indicating that the DNA methylation change may contribute to the Has2 enhancer's regulating function. CONCLUSIONS DNA methylation is developmentally regulated for genes essential to heart development, and abnormal DNA methylation may contribute to congenital heart disease.
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Affiliation(s)
- Alyssa A. Chamberlain
- Division of Hematology, Department of Genetics, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY (A.A.C., M.L., A.A.M., Y.W., M.S., B.W., J.M.G., D.Z.)
| | - Mingyan Lin
- Division of Hematology, Department of Genetics, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY (A.A.C., M.L., A.A.M., Y.W., M.S., B.W., J.M.G., D.Z.)
| | - Rolanda L. Lister
- Division of Hematology, Department of Obstetrics & Gynecology and Women's Health (Maternal & Fetal Medicine), Albert Einstein College of Medicine of Yeshiva University, Bronx, NY (R.L.L.)
| | - Alex A. Maslov
- Division of Hematology, Department of Genetics, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY (A.A.C., M.L., A.A.M., Y.W., M.S., B.W., J.M.G., D.Z.)
| | - Yidong Wang
- Division of Hematology, Department of Genetics, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY (A.A.C., M.L., A.A.M., Y.W., M.S., B.W., J.M.G., D.Z.)
| | - Masako Suzuki
- Division of Hematology, Department of Genetics, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY (A.A.C., M.L., A.A.M., Y.W., M.S., B.W., J.M.G., D.Z.)
| | - Bingruo Wu
- Division of Hematology, Department of Genetics, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY (A.A.C., M.L., A.A.M., Y.W., M.S., B.W., J.M.G., D.Z.)
| | - John M. Greally
- Division of Hematology, Department of Medicine, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY (J.M.G.)
- Division of Hematology, Department of Pediatrics, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY (J.M.G.)
- Division of Hematology, Department of Genetics, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY (A.A.C., M.L., A.A.M., Y.W., M.S., B.W., J.M.G., D.Z.)
| | - Deyou Zheng
- Division of Hematology, Department of Neurology, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY (D.Z.)
- Division of Hematology, Department of Neuroscience, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY (D.Z.)
- Division of Hematology, Department of Genetics, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY (A.A.C., M.L., A.A.M., Y.W., M.S., B.W., J.M.G., D.Z.)
| | - Bin Zhou
- Division of Cardiology, Departments of Medicine, Pediatrics, and Genetics, and Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY (B.Z.)
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China (B.Z.)
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28
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Abstract
Regeneration of adult skeletal muscle following injury occurs through the activation of satellite cells, an injury-sensitive muscle stem cell population that proliferates, differentiates, and fuses with injured myofibers. Members of the myocyte enhancer factor 2 (MEF2) family of transcription factors play essential roles in muscle differentiation during embryogenesis, but their potential contributions to adult muscle regeneration have not been systematically explored. To investigate the potential involvement of MEF2 factors in muscle regeneration, we conditionally deleted the Mef2a, c, and d genes, singly and in combination, within satellite cells in mice, using tamoxifen-inducible Cre recombinase under control of the satellite cell-specific Pax7 promoter. We show that deletion of individual Mef2 genes has no effect on muscle regeneration in response to cardiotoxin injury. However, combined deletion of the Mef2a, c, and d genes results in a blockade to regeneration. Satellite cell-derived myoblasts lacking MEF2A, C, and D proliferate normally in culture, but cannot differentiate. The absence of MEF2A, C, and D in satellite cells is associated with aberrant expression of a broad collection of known and unique protein-coding and long noncoding RNA genes. These findings reveal essential and redundant roles of MEF2A, C, and D in satellite cell differentiation and identify a MEF2-dependent transcriptome associated with skeletal muscle regeneration.
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29
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Oct-2 transcription factor binding activity and expression up-regulation in rat cerebral ischaemia is associated with a diminution of neuronal damage in vitro. Neuromolecular Med 2013; 16:332-49. [PMID: 24282026 DOI: 10.1007/s12017-013-8279-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 11/20/2013] [Indexed: 11/27/2022]
Abstract
Brain plasticity provides a mechanism to compensate for lesions produced as a result of stroke. The present study aims to identify new transcription factors (TFs) following focal cerebral ischaemia in rat as potential therapeutic targets. A transient focal cerebral ischaemia model was used for TF-binding activity and TF-TF interaction profile analysis. A permanent focal cerebral ischaemia model was used for the transcript gene analysis and for the protein study. The identification of TF variants, mRNA analysis, and protein study was performed using conventional polymerase chain reaction (PCR), qPCR, and Western blot and immunofluorescence, respectively. Rat cortical neurons were transfected with small interfering RNA against the TF in order to study its role. The TF-binding analysis revealed a differential binding activity of the octamer family in ischaemic brain in comparison with the control brain samples both in acute and late phases. In this study, we focused on Oct-2 TF. Five of the six putative Oct-2 transcript variants are expressed in both control and ischaemic rat brain, showing a significant increase in the late phase of ischaemia. Oct-2 protein showed neuronal localisation both in control and ischaemic rat brain cortical slices. Functional studies revealed that Oct-2 interacts with TFs involved in important brain processes (neuronal and vascular development) and basic cellular functions and that Oct-2 knockdown promotes neuronal injury. The present study shows that Oct-2 expression and binding activity increase in the late phase of cerebral ischaemia and finds Oct-2 to be involved in reducing ischaemic-mediated neuronal injury.
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30
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Vijayakumar A, Buffin NJ, Gallagher EJ, Blank J, Wu Y, Yakar S, LeRoith D. Deletion of growth hormone receptors in postnatal skeletal muscle of male mice does not alter muscle mass and response to pathological injury. Endocrinology 2013; 154:3776-83. [PMID: 23861377 PMCID: PMC5398538 DOI: 10.1210/en.2013-1209] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In this study, we investigated whether loss of GH receptor (GHR) signaling in postnatal skeletal muscle alters muscle mass and regenerative ability in adult mice and whether this was dependent on IGF-1 receptor (IGF-1R) signaling. To do so, we used mouse models with skeletal muscle-specific loss of GHR signaling (mGHRKO), IGF-1R and insulin receptor signaling (MKR), or both GHR and IGF-1R/insulin receptor signaling (mGHRKO/MKR). We did not find a reduction in muscle cross-sectional area, fiber type composition, or response to pathological muscle injury in male mGHRKO and mGHRKO/MKR mice when compared with control and MKR mice, respectively. This could potentially be explained by unchanged skeletal muscle Igf-1 expression in mGHRKO and mGHRKO/MKR mice relative to control and MKR mice, respectively. Furthermore, MKR and mGHRKO/MKR mice, but not mGHRKO mice, demonstrated reduced fiber fusion after cardiotoxin injection, suggesting that IGF-1, and not GH, promotes fiber fusion in adult mice. In summary, our data suggest that GHR signaling in postnatal skeletal muscle does not play a significant role in regulating muscle mass or muscle regeneration. Additionally, in our model, muscle Igf-1 expression is not dependent on GHR signaling in postnatal skeletal muscle.
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MESH Headings
- Animals
- Cardiotoxins/toxicity
- Diabetes Mellitus/drug therapy
- Diabetes Mellitus/metabolism
- Growth Hormone/metabolism
- Humans
- Insulin/metabolism
- Insulin/therapeutic use
- Insulin Resistance
- Insulin-Like Growth Factor I/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Muscle Development
- Muscle, Skeletal/cytology
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/pathology
- Muscle, Skeletal/physiology
- Receptor, IGF Type 1/biosynthesis
- Receptor, IGF Type 1/genetics
- Receptor, IGF Type 1/metabolism
- Receptor, Insulin/genetics
- Receptor, Insulin/metabolism
- Receptors, Somatotropin/genetics
- Receptors, Somatotropin/metabolism
- Regeneration
- Signal Transduction/drug effects
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Affiliation(s)
- Archana Vijayakumar
- MD, PhD, Division of Endocrinology, Metabolism, and Bone Diseases, Department of Medicine, Mount Sinai School of Medicine, One Gustave L. Levy Place, Box 1055, New York, New York 10029.
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31
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Molkentin JD. Parsing good versus bad signaling pathways in the heart: role of calcineurin-nuclear factor of activated T-cells. Circ Res 2013; 113:16-9. [PMID: 23788503 DOI: 10.1161/circresaha.113.301667] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Nine years ago, we published an article that suggested a specialized role for calcineurin–nuclear factor of activated T-cells (NFAT) signaling in regulating pathological cardiac hypertrophy preferentially over physiological growth and, in fact, the later response was associated with reduced calcineurin-NFAT activity. Since this time we and others have continued to uncover how this signaling effector pathway functions in the heart in regulating specific aspects of the growth response during disease and with exercise.
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Affiliation(s)
- Jeffery D Molkentin
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Howard Hughes Medical Institute, Cincinnati, OH 45229, USA.
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32
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Scott JA, Klutho PJ, El Accaoui R, Nguyen E, Venema AN, Xie L, Jiang S, Dibbern M, Scroggins S, Prasad AM, Luczak ED, Davis MK, Li W, Guan X, Backs J, Schlueter AJ, Weiss RM, Miller FJ, Anderson ME, Grumbach IM. The multifunctional Ca²⁺/calmodulin-dependent kinase IIδ (CaMKIIδ) regulates arteriogenesis in a mouse model of flow-mediated remodeling. PLoS One 2013; 8:e71550. [PMID: 23951185 PMCID: PMC3738514 DOI: 10.1371/journal.pone.0071550] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 07/01/2013] [Indexed: 11/18/2022] Open
Abstract
Objective Sustained hemodynamic stress mediated by high blood flow promotes arteriogenesis, the outward remodeling of existing arteries. Here, we examined whether Ca2+/calmodulin-dependent kinase II (CaMKII) regulates arteriogenesis. Methods and Results Ligation of the left common carotid led to an increase in vessel diameter and perimeter of internal and external elastic lamina in the contralateral, right common carotid. Deletion of CaMKIIδ (CaMKIIδ−/−) abolished this outward remodeling. Carotid ligation increased CaMKII expression and was associated with oxidative activation of CaMKII in the adventitia and endothelium. Remodeling was abrogated in a knock-in model in which oxidative activation of CaMKII is abolished. Early after ligation, matrix metalloproteinase 9 (MMP9) was robustly expressed in the adventitia of right carotid arteries of WT but not CaMKIIδ−/− mice. MMP9 mainly colocalized with adventitial macrophages. In contrast, we did not observe an effect of CaMKIIδ deficiency on other proposed mediators of arteriogenesis such as expression of adhesion molecules or smooth muscle proliferation. Transplantation of WT bone marrow into CaMKIIδ−/− mice normalized flow-mediated remodeling. Conclusion CaMKIIδ is activated by oxidation under high blood flow conditions and is required for flow-mediated remodeling through a mechanism that includes increased MMP9 expression in bone marrow-derived cells invading the arterial wall.
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Affiliation(s)
- Jason A. Scott
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Iowa City VA Medical Center, Iowa City, Iowa, United States of America
| | - Paula J. Klutho
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Ramzi El Accaoui
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Emily Nguyen
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Ashlee N. Venema
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Litao Xie
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Iowa City VA Medical Center, Iowa City, Iowa, United States of America
| | - Shuxia Jiang
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Megan Dibbern
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Sabrina Scroggins
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Anand M. Prasad
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Elisabeth D. Luczak
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Melissa K. Davis
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Weiwei Li
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Xiaoqun Guan
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Johannes Backs
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Annette J. Schlueter
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Robert M. Weiss
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Francis J. Miller
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Iowa City VA Medical Center, Iowa City, Iowa, United States of America
| | - Mark E. Anderson
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Isabella M. Grumbach
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Iowa City VA Medical Center, Iowa City, Iowa, United States of America
- * E-mail:
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Li J, Vargas MAX, Kapiloff MS, Dodge-Kafka KL. Regulation of MEF2 transcriptional activity by calcineurin/mAKAP complexes. Exp Cell Res 2012; 319:447-54. [PMID: 23261540 DOI: 10.1016/j.yexcr.2012.12.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 11/28/2012] [Accepted: 12/13/2012] [Indexed: 10/27/2022]
Abstract
The calcium/calmodulin-dependent protein phosphatase calcineurin is required for the induction of transcriptional events that initiate and promote myogenic differentiation. An important effector for calcineurin in striated muscle is the transcription factor myocyte enhancer factor 2 (MEF2). The targeting of the enzyme and substrate to specific intracellular compartments by scaffold proteins often confers specificity in phosphatase activity. We now show that the scaffolding protein mAKAP organizes a calcineurin/MEF2 signaling complex in myocytes, regulating gene transcription. A calcineurin/mAKAP/MEF2 complex can be isolated from C2C12 cells and cardiac myocytes, and the calcineurin/MEF2 association is dependent on mAKAP expression. We have identified a peptide comprising the calcineurin binding domain in mAKAP that can disrupt the binding of the phosphatase to the scaffold in vivo. Dominant interference of calcineurin/mAKAP binding blunts the increase in MEF2 transcriptional activity seen during myoblast differentiation, as well as the expression of endogenous MEF2-target genes. Furthermore, disruption of calcineurin binding to mAKAP in cardiac myocytes inhibits adrenergic-induced cellular hypertrophy. Together these data illustrate the importance of calcineurin anchoring by the mAKAP scaffold for MEF2 regulation.
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Affiliation(s)
- Jinliang Li
- Cardiac Signal Transduction and Cellular Biology Laboratory, Interdisciplinary Stem Cell Institute, Department of Pediatrics, University of Miami Miller School of Medicine, Miami, FL 33101, United States
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Dionyssiou MG, Nowacki NB, Hashemi S, Zhao J, Kerr A, Tsushima RG, McDermott JC. Cross-talk between glycogen synthase kinase 3β (GSK3β) and p38MAPK regulates myocyte enhancer factor 2 (MEF2) activity in skeletal and cardiac muscle. J Mol Cell Cardiol 2012; 54:35-44. [PMID: 23137781 DOI: 10.1016/j.yjmcc.2012.10.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 10/26/2012] [Accepted: 10/28/2012] [Indexed: 12/21/2022]
Abstract
Characterizing the signaling network that controls MEF2 transcription factors is crucial for understanding skeletal and cardiac muscle gene expression. Glycogen synthase kinase 3β (GSK3β) regulates MEF2 activity indirectly through reciprocal regulation of p38MAPK. Cross-talk between GSK3β and p38MAPK regulates MEF2 activity in skeletal and cardiac muscle. Understanding cross-talk in the signaling network converging at MEF2 control has therapeutic implications in cardiac and skeletal muscle pathology. Glycogen synthase kinase 3β (GSK3β) is a known regulator of striated muscle gene expression suppressing both myogenesis and cardiomyocyte hypertrophy. Since myocyte enhancer factor 2 (MEF2) proteins are key transcriptional regulators in both systems, we assessed whether MEF2 is a target for GSK3β. Pharmacological inhibition of GSK3β resulted in enhanced MEF2A/D expression and transcriptional activity in skeletal myoblasts and cardiac myocytes. Even though in silico analysis revealed GSK3β consensus (S/T)XXX(S/T) sites on MEF2A, a subsequent in vitro kinase assay revealed that MEF2A is only a weak substrate. However, we did observe a posttranslational modification in MEF2A in skeletal myoblasts treated with a GSK3β inhibitor which coincided with increased p38MAPK phosphorylation, a potent MEF2A activator, indicating that GSK3β inhibition may de-repress p38MAPK. Heart specific excision of GSK3β in mice also resulted in up-regulation of p38MAPK activity. Interestingly, upon pharmacological p38MAPK inhibition (SB203580), GSK3β inhibition loses its effect on MEF2 transcriptional activity suggesting potent cross-talk between the two pathways. Thus we have documented that cross-talk between p38MAPK and GSK3β signaling converges on MEF2 activity having potential consequences for therapeutic modulation of cardiac and skeletal muscle gene expression.
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Affiliation(s)
- M G Dionyssiou
- Department of Biology, York University, 4700 Keele St., Toronto, Ontario, Canada M3J 1P3
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Ye J, Cardona M, Llovera M, Comella JX, Sanchis D. Translation of Myocyte Enhancer Factor-2 is induced by hypertrophic stimuli in cardiomyocytes through a Calcineurin-dependent pathway. J Mol Cell Cardiol 2012; 53:578-87. [DOI: 10.1016/j.yjmcc.2012.07.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 07/18/2012] [Accepted: 07/19/2012] [Indexed: 10/28/2022]
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Shi X, Wallis AM, Gerard RD, Voelker KA, Grange RW, DePinho RA, Garry MG, Garry DJ. Foxk1 promotes cell proliferation and represses myogenic differentiation by regulating Foxo4 and Mef2. J Cell Sci 2012; 125:5329-37. [PMID: 22956541 DOI: 10.1242/jcs.105239] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
In response to severe injury, adult skeletal muscle exhibits a remarkable regenerative capacity due to a resident muscle stem/progenitor cell population. While a number of factors are expressed in the muscle progenitor cell (MPC) population, the molecular networks that govern this cell population remain an area of active investigation. In this study, utilizing knockdown techniques and overexpression of Foxk1 in the myogenic lineage, we observed dysregulation of Foxo and Mef2 downstream targets. Utilizing an array of technologies, we establish that Foxk1 represses the transcriptional activity of Foxo4 and Mef2 and physically interacts with Foxo4 and Mef2, thus promoting MPC proliferation and antagonizing the myogenic lineage differentiation program, respectively. Correspondingly, knockdown of Foxk1 in C2C12 myoblasts results in cell cycle arrest, and Foxk1 overexpression in C2C12CAR myoblasts retards muscle differentiation. Collectively, we have established that Foxk1 promotes MPC proliferation by repressing Foxo4 transcriptional activity and inhibits myogenic differentiation by repressing Mef2 activity. These studies enhance our understanding of the transcriptional networks that regulate the MPC population and muscle regeneration.
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Affiliation(s)
- Xiaozhong Shi
- Lillehei Heart Institute, University of Minnesota-Twin Cities, Minneapolis, MN 55455, USA
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37
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Scott JA, Xie L, Li H, Li W, He JB, Sanders PN, Carter AB, Backs J, Anderson ME, Grumbach IM. The multifunctional Ca2+/calmodulin-dependent kinase II regulates vascular smooth muscle migration through matrix metalloproteinase 9. Am J Physiol Heart Circ Physiol 2012; 302:H1953-64. [PMID: 22427508 DOI: 10.1152/ajpheart.00978.2011] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The multifunctional CaMKII has been implicated in vascular smooth muscle cell (VSMC) migration, but little is known regarding its downstream targets that mediate migration. Here, we examined whether CaMKII regulates migration through modulation of matrix metalloproteinase 9 (MMP9). Using CaMKIIδ(-/-) mice as a model system, we evaluated migration and MMP9 regulation in vitro and in vivo. After ligation of the common carotid artery, CaMKII was activated in the neointima as determined by oxidation and autophosphorylation. We found that MMP9 was robustly expressed in the neointima and adventitia of carotid-ligated wild-type (WT) mice but was barely detectable in CaMKIIδ(-/-) mice. The perimeter of the external elastic lamina, a correlate of migration-related outward remodeling, was increased in WT but not in CaMKIIδ(-/-) mice. Migration induced by serum, platelet-derived growth factor, and tumor necrosis factor-α (TNF-α) was significantly decreased in CaMKIIδ(-/-) as compared with WT VSMCs, but migration was rescued with adenoviral overexpression of MMP9 in CaMKIIδ(-/-) VSMCs. Likewise, overexpression of CaMKIIδ in CaMKIIδ(-/-) VSMCs increased migration, whereas an oxidation-resistant mutant of CaMKIIδ did not. TNF-α strongly induced CaMKII oxidation and autophosphorylation as well as MMP9 activity, mRNA, and protein levels in WT, but not in CaMKIIδ(-/-) VSMC. Surprisingly, TNF-α strongly induced MMP9 promoter activity in WT and CaMKIIδ(-/-) VSMC. However, the MMP9 mRNA stability was significantly decreased in CaMKIIδ(-/-) VSMC. Our data demonstrate that CaMKII promotes VSMC migration through posttranscriptional regulation of MMP9 and suggest that CaMKII effects on MMP9 expression may be a therapeutic pathway in vascular injury.
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Affiliation(s)
- Jason A Scott
- Department of Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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Pane LS, Zhang Z, Ferrentino R, Huynh T, Cutillo L, Baldini A. Tbx1 is a negative modulator of Mef2c. Hum Mol Genet 2012; 21:2485-96. [PMID: 22367967 PMCID: PMC3349424 DOI: 10.1093/hmg/dds063] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The developmental role of the T-box transcription factor Tbx1 is exquisitely dosage-sensitive. In this study, we performed a microarray-based transcriptome analysis of E9.5 embryo tissues across a previously generated Tbx1 mouse allelic series. This analysis identified several genes whose expression was affected by Tbx1 dosage. Interestingly, we found that the expression of the gene encoding the cardiogenic transcription factor Mef2c was negatively correlated to Tbx1 dosage. In vivo data revealed Mef2c up-regulation in the second heart field (SHF) of Tbx1 null mutant embryos compared with wild-type littermates at E9.5. Conversely, Mef2c expression was decreased in the SHF and in somites of Tbx1 gain-of-function mutants. These results are consistent with the described role of Tbx1 in suppressing cardiac progenitor cell differentiation and indicate also a negative effect of Tbx1 on Mef2c during skeletal muscle differentiation. We show that Tbx1 occupies conserved regulatory regions of the Mef2c locus, suggesting a direct effect on Mef2c transcription. However, we also show that Tbx1 interferes with the Gata4→ Mef2c regulatory pathway. Overall, our study uncovered a target of Tbx1 with critical developmental roles, so highlighting the power of the dosage gradient approach that we used.
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Affiliation(s)
- Luna Simona Pane
- Institute of Genetics and Biophysics, National Research Council, 80131 Naples, Italy
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Backs J, Worst BC, Lehmann LH, Patrick DM, Jebessa Z, Kreusser MM, Sun Q, Chen L, Heft C, Katus HA, Olson EN. Selective repression of MEF2 activity by PKA-dependent proteolysis of HDAC4. ACTA ACUST UNITED AC 2012; 195:403-15. [PMID: 22042619 PMCID: PMC3206346 DOI: 10.1083/jcb.201105063] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Histone deacetylase 4 (HDAC4) regulates numerous gene expression programs through its signal-dependent repression of myocyte enhancer factor 2 (MEF2) and serum response factor (SRF) transcription factors. In cardiomyocytes, calcium/calmodulin-dependent protein kinase II (CaMKII) signaling promotes hypertrophy and pathological remodeling, at least in part by phosphorylating HDAC4, with consequent stimulation of MEF2 activity. In this paper, we describe a novel mechanism whereby protein kinase A (PKA) overcomes CaMKII-mediated activation of MEF2 by regulated proteolysis of HDAC4. PKA induces the generation of an N-terminal HDAC4 cleavage product (HDAC4-NT). HDAC4-NT selectively inhibits activity of MEF2 but not SRF, thereby antagonizing the prohypertrophic actions of CaMKII signaling without affecting cardiomyocyte survival. Thus, HDAC4 functions as a molecular nexus for the antagonistic actions of the CaMKII and PKA pathways. These findings have implications for understanding the molecular basis of cardioprotection and other cellular processes in which CaMKII and PKA exert opposing effects.
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Affiliation(s)
- Johannes Backs
- Department of Cardiology, University of Heidelberg, 69120 Heidelberg, Germany.
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Vijayakumar A, Wu Y, Sun H, Li X, Jeddy Z, Liu C, Schwartz GJ, Yakar S, LeRoith D. Targeted loss of GHR signaling in mouse skeletal muscle protects against high-fat diet-induced metabolic deterioration. Diabetes 2012; 61:94-103. [PMID: 22187377 PMCID: PMC3237669 DOI: 10.2337/db11-0814] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Growth hormone (GH) exerts diverse tissue-specific metabolic effects that are not revealed by global alteration of GH action. To study the direct metabolic effects of GH in the muscle, we specifically inactivated the growth hormone receptor (ghr) gene in postnatal mouse skeletal muscle using the Cre/loxP system (mGHRKO model). The metabolic state of the mGHRKO mice was characterized under lean and obese states. High-fat diet feeding in the mGHRKO mice was associated with reduced adiposity, improved insulin sensitivity, lower systemic inflammation, decreased muscle and hepatic triglyceride content, and greater energy expenditure compared with control mice. The obese mGHRKO mice also had an increased respiratory exchange ratio, suggesting increased carbohydrate utilization. GH-regulated suppressor of cytokine signaling-2 (socs2) expression was decreased in obese mGHRKO mice. Interestingly, muscles of both lean and obese mGHRKO mice demonstrated a higher interleukin-15 and lower myostatin expression relative to controls, indicating a possible mechanism whereby GHR signaling in muscle could affect liver and adipose tissue function. Thus, our study implicates skeletal muscle GHR signaling in mediating insulin resistance in obesity and, more importantly, reveals a novel role of muscle GHR signaling in facilitating cross-talk between muscle and other metabolic tissues.
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Affiliation(s)
- Archana Vijayakumar
- Division of Endocrinology, Diabetes, and Bone Diseases, Department of Medicine, Mount Sinai School of Medicine, New York, New York
| | - YingJie Wu
- Division of Endocrinology, Diabetes, and Bone Diseases, Department of Medicine, Mount Sinai School of Medicine, New York, New York
| | - Hui Sun
- Division of Endocrinology, Diabetes, and Bone Diseases, Department of Medicine, Mount Sinai School of Medicine, New York, New York
| | - Xiaosong Li
- Departments of Medicine and Neuroscience, Albert Einstein College of Medicine, Bronx, New York
| | - Zuha Jeddy
- Division of Endocrinology, Diabetes, and Bone Diseases, Department of Medicine, Mount Sinai School of Medicine, New York, New York
| | - Chengyu Liu
- Transgenic Core Facility, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Gary J. Schwartz
- Departments of Medicine and Neuroscience, Albert Einstein College of Medicine, Bronx, New York
| | - Shoshana Yakar
- Division of Endocrinology, Diabetes, and Bone Diseases, Department of Medicine, Mount Sinai School of Medicine, New York, New York
| | - Derek LeRoith
- Division of Endocrinology, Diabetes, and Bone Diseases, Department of Medicine, Mount Sinai School of Medicine, New York, New York
- Corresponding authors: Derek LeRoith, , and Shoshana Yakar,
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Oxidation of CaMKII determines the cardiotoxic effects of aldosterone. Nat Med 2011; 17:1610-8. [PMID: 22081025 DOI: 10.1038/nm.2506] [Citation(s) in RCA: 191] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 09/12/2011] [Indexed: 02/07/2023]
Abstract
Excessive activation of the β-adrenergic, angiotensin II (Ang II) and aldosterone signaling pathways promotes mortality after myocardial infarction, and antagonists targeting these pathways are core therapies for treating this condition. Catecholamines and Ang II activate the multifunctional Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), the inhibition of which prevents isoproterenol-mediated and Ang II-mediated cardiomyopathy. Here we show that aldosterone exerts direct toxic actions on myocardium by oxidative activation of CaMKII, causing cardiac rupture and increased mortality in mice after myocardial infarction. Aldosterone induces CaMKII oxidation by recruiting NADPH oxidase, and this oxidized and activated CaMKII promotes matrix metalloproteinase 9 (MMP9) expression in cardiomyocytes. Myocardial CaMKII inhibition, overexpression of methionine sulfoxide reductase A (an enzyme that reduces oxidized CaMKII) or NADPH oxidase deficiency prevented aldosterone-enhanced cardiac rupture after myocardial infarction. These findings show that oxidized myocardial CaMKII mediates the cardiotoxic effects of aldosterone on the cardiac matrix and establish CaMKII as a nodal signal for the neurohumoral pathways associated with poor outcomes after myocardial infarction.
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Abstract
RATIONALE The degradation of proteins by the ubiquitin proteasome system (UPS) is required for the maintenance of cellular homeostasis in the heart. An important regulator of metabolic homeostasis is AMP-activated protein kinase (AMPK). AMPK activation inhibits protein synthesis and activates autophagy, but whether AMPK plays a role in regulating protein breakdown through the UPS in the heart is not known. OBJECTIVE To determine whether AMPK enhances UPS-mediated protein degradation by directly regulating the ubiquitin ligases Atrogin-1 and muscle RING finger protein 1 (MuRF1) in the heart. METHODS AND RESULTS Nutrient deprivation and pharmacological or genetic activation of AMPK increased mRNA expression and protein levels of Atrogin-1 and MuRF1 and consequently enhanced protein degradation in neonatal cardiomyocytes. Inhibition of AMPK abrogated these effects. Using gene reporter and chromatin immunoprecipitation assays, we found that AMPK regulates MuRF1 expression by acting through the myocyte enhancer factor 2 (MEF2). We further validated these findings in vivo using MEF2-LacZ reporter mice. Furthermore, we demonstrated in adult cardiomyocytes that MuRF1 is necessary for AMPK-mediated proteolysis through the UPS in the heart. Consequently, MuRF1 knockout mice were protected from severe cardiac dysfunction during fasting. CONCLUSIONS AMPK regulates the transcription of Atrogin-1 and MuRF1 and enhances UPS-mediated protein degradation in heart. Specifically, AMPK regulates MuRF1 through the transcription factor MEF2. The absence of MuRF1 in the heart preserves cardiac function during fasting. The results strengthen the hypothesis that AMPK serves as a modulator of intracellular protein degradation in the heart.
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Affiliation(s)
- Kedryn K Baskin
- Department of Internal Medicine, Division of Cardiology, University of Texas Health Science Center, Houston, TX 77030, USA
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Functional Gene Expression Analysis of Tissue-Specific Isoforms of Mef2c. Cell Mol Neurobiol 2011; 32:129-39. [DOI: 10.1007/s10571-011-9743-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Accepted: 07/27/2011] [Indexed: 01/04/2023]
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Simmons BJ, Cohen TJ, Bedlack R, Yao TP. HDACs in skeletal muscle remodeling and neuromuscular disease. Handb Exp Pharmacol 2011; 206:79-101. [PMID: 21879447 DOI: 10.1007/978-3-642-21631-2_5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Skeletal muscle is made of heterogeneous myofibers with different contractile and metabolic properties. The diverse functionality of myofibers enables skeletal muscle to carry out different tasks from maintaining body posture to performing active movements. In addition to motility, skeletal muscle, which constitutes 40% of body mass, is also a key target of insulin action and performs an essential function in glucose metabolism. Adult skeletal muscle is a highly adaptive organ system and can undergo specific changes in contractile and metabolic properties to meet different functional demands. This plasticity of myofibers reflects a highly coordinated change in gene expression program that is controlled by neural activity. The capacity for on-demand remodeling confers skeletal muscle the remarkable adaptability important for animal survival; its dysregulation, however, could contribute to muscle and metabolic diseases. How neural activity dictates transcriptional programming to modify muscle functionality and diversity is a fundamental issue. Recent studies have identified members of class IIa HDACs as important effectors in both physiological and pathological muscle remodeling. By way of modifying myofiber properties, pharmacological manipulation of IIa HDACs activity could have potential therapeutic utility in the treatment of muscle disorders.
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Affiliation(s)
- Bryan J Simmons
- Department of Pharmacology and Cancer Biology, Duke University, C325 LSRC, DUMC, 3813, Durham, NC 27710, USA
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45
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Torgersen JS, Takle H, Andersen Ø. Differential spatial expression of mef2 paralogs during cardiac development in Atlantic cod (Gadus morhua). Comp Biochem Physiol B Biochem Mol Biol 2010; 158:181-7. [PMID: 21109015 DOI: 10.1016/j.cbpb.2010.11.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 11/16/2010] [Accepted: 11/16/2010] [Indexed: 11/25/2022]
Abstract
The myogenic enhancer factor 2 (Mef2) transcription factors are known for their role in the control of cardiac development. Here we describe the spatial and temporal expression patterns of five Atlantic cod mef2 genes designated as mef2a, mef2cI, mef2cII, mef2dI and mef2dII during cardiogenesis. Whole mount in situ hybridization showed that mef2a and mef2dI were expressed in both cardiac ring and cone prior to looping morphogenesis, while mef2dII expression was only detectable in the cardiac ring. The mef2cI and mef2cII paralogs displayed different spatial expression patterns in the heart tube with a venous and arterial pole preference, respectively. After the cardiac loop formation mef2cI was expressed in cells of the ventricle and lateral arteries, while mef2cII appeared more abundant and was also present in the atrium. Larvae raised at constant 8 °C showed malformed morphology of the lateral arteries, and the transcription of both mef2c variants was highly elevated compared to those kept at 4 °C. Acute temperature stress also resulted in deviations in the expression of the mef2c paralogs, and the treated embryos displayed defects in the developing heart, including impaired fusion of the bilateral primordia and truncated heart tubes.
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46
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Gundersen K. Excitation-transcription coupling in skeletal muscle: the molecular pathways of exercise. Biol Rev Camb Philos Soc 2010; 86:564-600. [PMID: 21040371 PMCID: PMC3170710 DOI: 10.1111/j.1469-185x.2010.00161.x] [Citation(s) in RCA: 170] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Muscle fibres have different properties with respect to force, contraction speed, endurance, oxidative/glycolytic capacity etc. Although adult muscle fibres are normally post-mitotic with little turnover of cells, the physiological properties of the pre-existing fibres can be changed in the adult animal upon changes in usage such as after exercise. The signal to change is mainly conveyed by alterations in the patterns of nerve-evoked electrical activity, and is to a large extent due to switches in the expression of genes. Thus, an excitation-transcription coupling must exist. It is suggested that changes in nerve-evoked muscle activity lead to a variety of activity correlates such as increases in free intracellular Ca2+ levels caused by influx across the cell membrane and/or release from the sarcoplasmatic reticulum, concentrations of metabolites such as lipids and ADP, hypoxia and mechanical stress. Such correlates are detected by sensors such as protein kinase C (PKC), calmodulin, AMP-activated kinase (AMPK), peroxisome proliferator-activated receptor δ (PPARδ), and oxygen dependent prolyl hydroxylases that trigger intracellular signaling cascades. These complex cascades involve several transcription factors such as nuclear factor of activated T-cells (NFAT), myocyte enhancer factor 2 (MEF2), myogenic differentiation factor (myoD), myogenin, PPARδ, and sine oculis homeobox 1/eyes absent 1 (Six1/Eya1). These factors might act indirectly by inducing gene products that act back on the cascade, or as ultimate transcription factors binding to and transactivating/repressing genes for the fast and slow isoforms of various contractile proteins and of metabolic enzymes. The determination of size and force is even more complex as this involves not only intracellular signaling within the muscle fibres, but also muscle stem cells called satellite cells. Intercellular signaling substances such as myostatin and insulin-like growth factor 1 (IGF-1) seem to act in a paracrine fashion. Induction of hypertrophy is accompanied by the satellite cells fusing to myofibres and thereby increasing the capacity for protein synthesis. These extra nuclei seem to remain part of the fibre even during subsequent atrophy as a form of muscle memory facilitating retraining. In addition to changes in myonuclear number during hypertrophy, changes in muscle fibre size seem to be caused by alterations in transcription, translation (per nucleus) and protein degradation.
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Affiliation(s)
- Kristian Gundersen
- Department of Molecular Biosciences, University of Oslo, P.O. Box 1041, Blindern, N-0316 Oslo, Norway.
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Heterogeneous myocyte enhancer factor-2 (Mef2) activation in myocytes predicts focal scarring in hypertrophic cardiomyopathy. Proc Natl Acad Sci U S A 2010; 107:18097-102. [PMID: 20923879 DOI: 10.1073/pnas.1012826107] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Unknown molecular responses to sarcomere protein gene mutations account for pathologic remodeling in hypertrophic cardiomyopathy (HCM), producing myocyte growth and increased cardiac fibrosis. To determine if hypertrophic signals activated myocyte enhancer factor-2 (Mef2), we studied mice carrying the HCM mutation, myosin heavy-chain Arg403Gln, (MHC(403/+)) and an Mef2-dependent β-galactosidase reporter transgene. In young, prehypertrophic MHC(403/+) mice the reporter was not activated. In hypertrophic hearts, activation of the Mef2-dependent reporter was remarkably heterogeneous and was observed consistently in myocytes that bordered fibrotic foci with necrotic cells, MHC(403/+) myocytes with Mef2-dependent reporter activation reexpressed the fetal myosin isoform (βMHC), a molecular marker of hypertrophy, although MHC(403/+) myocytes with or without βMHC expression were comparably enlarged over WT myocytes. To consider Mef2 roles in severe HCM, we studied homozygous MHC(403/403) mice, which have accelerated remodeling, widespread myocyte necrosis, and neonatal lethality. Levels of phosphorylated class II histone deacetylases that activate Mef2 were substantially increased in MHC(403/403) hearts, but Mef2-dependent reporter activation was patchy. Sequential analyses showed myocytes increased Mef2-dependent reporter activity before death. Our data dissociate myocyte hypertrophy, a consistent response in HCM, from heterogeneous Mef2 activation and reexpression of a fetal gene program. The temporal and spatial relationship of Mef2-dependent gene activation with myocyte necrosis and fibrosis in MHC(403/+) and MHC(403/403) hearts defines Mef2 activation as a molecular signature of stressed HCM myocytes that are poised to die.
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Magli A, Angelelli C, Ganassi M, Baruffaldi F, Matafora V, Battini R, Bachi A, Messina G, Rustighi A, Del Sal G, Ferrari S, Molinari S. Proline isomerase Pin1 represses terminal differentiation and myocyte enhancer factor 2C function in skeletal muscle cells. J Biol Chem 2010; 285:34518-27. [PMID: 20801874 PMCID: PMC2966067 DOI: 10.1074/jbc.m110.104133] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Reversible proline-directed phosphorylation at Ser/Thr-Pro motifs has an essential role in myogenesis, a multistep process strictly regulated by several signaling pathways that impinge on two families of myogenic effectors, the basic helix-loop-helix myogenic transcription factors and the MEF2 (myocyte enhancer factor 2) proteins. The question of how these signals are deciphered by the myogenic effectors remains largely unaddressed. In this study, we show that the peptidyl-prolyl isomerase Pin1, which catalyzes the isomerization of phosphorylated Ser/Thr-Pro peptide bonds to induce conformational changes of its target proteins, acts as an inhibitor of muscle differentiation because its knockdown in myoblasts promotes myotube formation. With the aim of clarifying the mechanism of Pin1 function in skeletal myogenesis, we investigated whether MEF2C, a critical regulator of the myogenic program that is the end point of several signaling pathways, might serve as a/the target for the inhibitory effects of Pin1 on muscle differentiation. We show that Pin1 interacts selectively with phosphorylated MEF2C in skeletal muscle cells, both in vitro and in vivo. The interaction with Pin1 requires two novel critical phospho-Ser/Thr-Pro motifs in MEF2C, Ser98 and Ser110, which are phosphorylated in vivo. Overexpression of Pin1 decreases MEF2C stability and activity and its ability to cooperate with MyoD to activate myogenic conversion. Collectively, these findings reveal a novel role for Pin1 as a regulator of muscle terminal differentiation and suggest that Pin1-mediated repression of MEF2C function could contribute to this function.
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Affiliation(s)
- Alessandro Magli
- Department of Biomedical Sciences, University of Modena and Reggio Emilia, 41100 Modena, Italy
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Czubryt MP, Lamoureux L, Ramjiawan A, Abrenica B, Jangamreddy J, Swan K. Regulation of cardiomyocyte Glut4 expression by ZAC1. J Biol Chem 2010; 285:16942-50. [PMID: 20363751 DOI: 10.1074/jbc.m109.097246] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The transcription factor ZAC1 is expressed in a variety of tissues including the developing heart, but its physiological role is unclear. We examined the role of ZAC1 in regulating expression of the insulin-responsive glucose transporter GLUT4 and whether ZAC1 expression is altered in cardiomyocyte hypertrophy. We demonstrated expression of Zac1 mRNA and protein in rat cardiomyocytes by PCR and Western blotting, respectively. Using a combination of chromatin immunoprecipitation and luciferase assays, we showed that ZAC1 regulates Glut4 expression via a specific binding site in the Glut4 promoter. Overexpression of ZAC1 increased Glut4 mRNA and protein expression and resulted in increased glucose uptake in cardiomyocytes as determined by a fluorescent analog uptake assay. Induction of hypertrophy by phenylephrine or isoproterenol resulted in increased Zac1 expression. We identified a novel putative promoter in the Zac1 gene and demonstrated increased binding of MEF2 to this promoter in response to hypertrophic stimulation. MEF2 regulated transactivation of the Zac1 promoter and ZAC1 protein expression. This work identifies ZAC1 as a novel and previously unknown regulator of cardiomyocyte Glut4 expression and glucose uptake. Our results also implicate MEF2 as a regulator of ZAC1 expression in response to induction of hypertrophy.
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Affiliation(s)
- Michael P Czubryt
- Department of Physiology, University of Manitoba, Institute of Cardiovascular Sciences, St Boniface General Hospital Research Centre, Winnipeg, Manitoba R2H 2A6, Canada
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Li H, Li W, Gupta AK, Mohler PJ, Anderson ME, Grumbach IM. Calmodulin kinase II is required for angiotensin II-mediated vascular smooth muscle hypertrophy. Am J Physiol Heart Circ Physiol 2009; 298:H688-98. [PMID: 20023119 DOI: 10.1152/ajpheart.01014.2009] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Despite our understanding that medial smooth muscle hypertrophy is a central feature of vascular remodeling, the molecular pathways underlying this pathology are still not well understood. Work over the past decade has illustrated a potential role for the multifunctional calmodulin-dependent kinase CaMKII in smooth muscle cell contraction, growth, and migration. Here we demonstrate that CaMKII is enriched in vascular smooth muscle (VSM) and that CaMKII inhibition blocks ANG II-dependent VSM cell hypertrophy in vitro and in vivo. Specifically, systemic CaMKII inhibition with KN-93 prevented ANG II-mediated hypertension and medial hypertrophy in vivo. Adenoviral transduction with the CaMKII peptide inhibitor CaMKIIN abrogated ANG II-induced VSM hypertrophy in vitro, which was augmented by overexpression of CaMKII-delta2. Finally, we identify the downstream signaling components critical for ANG II- and CaMKII-mediated VSM hypertrophy. Specifically, we demonstrate that CaMKII induces VSM hypertrophy by regulating histone deacetylase 4 (HDAC4) activity, thereby stimulating activity of the hypertrophic transcription factor MEF2. MEF2 transcription is activated by ANG II in vivo and abrogated by the CaMKII inhibitor KN-93. Together, our studies identify a complete pathway for ANG II-triggered arterial VSM hypertrophy and identify new potential therapeutic targets for chronic human hypertension.
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Affiliation(s)
- Hui Li
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
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