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Katano W, Mori S, Sasaki S, Tajika Y, Tomita K, Takeuchi JK, Koshiba-Takeuchi K. Sall1 and Sall4 cooperatively interact with Myocd and SRF to promote cardiomyocyte proliferation by regulating CDK and cyclin genes. Development 2023; 150:dev201913. [PMID: 38014633 DOI: 10.1242/dev.201913] [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: 04/25/2023] [Accepted: 11/08/2023] [Indexed: 11/29/2023]
Abstract
Sall1 and Sall4 (Sall1/4), zinc-finger transcription factors, are expressed in the progenitors of the second heart field (SHF) and in cardiomyocytes during the early stages of mouse development. To understand the function of Sall1/4 in heart development, we generated heart-specific Sall1/4 functionally inhibited mice by forced expression of the truncated form of Sall4 (ΔSall4) in the heart. The ΔSall4-overexpression mice exhibited a hypoplastic right ventricle and outflow tract, both of which were derived from the SHF, and a thinner ventricular wall. We found that the numbers of proliferative SHF progenitors and cardiomyocytes were reduced in ΔSall4-overexpression mice. RNA-sequencing data showed that Sall1/4 act upstream of the cyclin-dependent kinase (CDK) and cyclin genes, and of key transcription factor genes for the development of compact cardiomyocytes, including myocardin (Myocd) and serum response factor (Srf). In addition, ChIP-sequencing and co-immunoprecipitation analyses revealed that Sall4 and Myocd form a transcriptional complex with SRF, and directly bind to the upstream regulatory regions of the CDK and cyclin genes (Cdk1 and Ccnb1). These results suggest that Sall1/4 are critical for the proliferation of cardiac cells via regulation of CDK and cyclin genes that interact with Myocd and SRF.
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Affiliation(s)
- Wataru Katano
- Graduate School of Life Sciences, Toyo University, 1-1-1, Izumino, Itakura-machi, Ora-gun, Gunma 374-0193, Japan
| | - Shunta Mori
- Faculty of Life Sciences, Department of Applied Biosciences, Toyo University, 1-1-1, Izumino, Itakura-machi, Ora-gun, Gunma 374-0193, Japan
| | - Shun Sasaki
- Graduate School of Life Sciences, Toyo University, 1-1-1, Izumino, Itakura-machi, Ora-gun, Gunma 374-0193, Japan
| | - Yuki Tajika
- Graduate School of Medicine, Gunma University, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan
- Department of Radiological Technology, Gunma Prefectural College of Health Sciences, 323-1, Kamioki-machi, Maebashi, Gunma 371-0052, Japan
| | - Koichi Tomita
- Graduate School of Biomedical Sciences, Tokushima University, 3-18-15, Kuramoto-cho, Tokushima 770-8503, Japan
| | - Jun K Takeuchi
- Department of Bio-informational Pharmacology, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo, Tokyo 113-8510, Japan
| | - Kazuko Koshiba-Takeuchi
- Graduate School of Life Sciences, Toyo University, 1-1-1, Izumino, Itakura-machi, Ora-gun, Gunma 374-0193, Japan
- Faculty of Life Sciences, Department of Applied Biosciences, Toyo University, 1-1-1, Izumino, Itakura-machi, Ora-gun, Gunma 374-0193, Japan
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2
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Andrews JC, Mok JW, Kanca O, Jangam S, Tifft C, Macnamara EF, Russell BE, Wang LK, Nelson SF, Bellen HJ, Yamamoto S, Malicdan MCV, Wangler MF. De novo variants in MRTFB have gain-of-function activity in Drosophila and are associated with a novel neurodevelopmental phenotype with dysmorphic features. Genet Med 2023; 25:100833. [PMID: 37013900 PMCID: PMC11533975 DOI: 10.1016/j.gim.2023.100833] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 03/22/2023] [Accepted: 03/23/2023] [Indexed: 04/03/2023] Open
Abstract
PURPOSE Myocardin-related transcription factor B (MRTFB) is an important transcriptional regulator, which promotes the activity of an estimated 300 genes but is not known to underlie a Mendelian disorder. METHODS Probands were identified through the efforts of the Undiagnosed Disease Network. Because the MRTFB protein is highly conserved between vertebrate and invertebrate model organisms, we generated a humanized Drosophila model expressing the human MRTFB protein in the same spatial and temporal pattern as the fly gene. Actin binding assays were used to validate the effect of the variants on MRTFB. RESULTS Here, we report 2 pediatric probands with de novo variants in MRTFB (p.R104G and p.A91P) and mild dysmorphic features, intellectual disability, global developmental delays, speech apraxia, and impulse control issues. Expression of the variants within wing tissues of a fruit fly model resulted in changes in wing morphology. The MRTFBR104G and MRTFBA91P variants also display a decreased level of actin binding within critical RPEL domains, resulting in increased transcriptional activity and changes in the organization of the actin cytoskeleton. CONCLUSION The MRTFBR104G and MRTFBA91P variants affect the regulation of the protein and underlie a novel neurodevelopmental disorder. Overall, our data suggest that these variants act as a gain of function.
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Affiliation(s)
- Jonathan C Andrews
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute, Houston, TX
| | - Jung-Wan Mok
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute, Houston, TX
| | - Oguz Kanca
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute, Houston, TX
| | - Sharayu Jangam
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute, Houston, TX
| | - Cynthia Tifft
- Undiagnosed Diseases Program, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD
| | - Ellen F Macnamara
- Undiagnosed Diseases Program, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD
| | - Bianca E Russell
- Division of Genetics, Department of Pediatrics, University of California, Los Angeles, Los Angeles, CA; Institute for Precision Health, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA
| | - Lee-Kai Wang
- Institute for Precision Health, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA
| | - Stanley F Nelson
- Institute for Precision Health, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute, Houston, TX; Department of Neuroscience, Baylor College of Medicine, Houston, TX
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute, Houston, TX; Department of Neuroscience, Baylor College of Medicine, Houston, TX
| | - May Christine V Malicdan
- Undiagnosed Diseases Program, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD.
| | - Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; Jan and Dan Duncan Neurological Research Institute, Houston, TX.
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3
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Trembley MA, Quijada P, Agullo-Pascual E, Tylock KM, Colpan M, Dirkx RA, Myers JR, Mickelsen DM, de Mesy Bentley K, Rothenberg E, Moravec CS, Alexis JD, Gregorio CC, Dirksen RT, Delmar M, Small EM. Mechanosensitive Gene Regulation by Myocardin-Related Transcription Factors Is Required for Cardiomyocyte Integrity in Load-Induced Ventricular Hypertrophy. Circulation 2018; 138:1864-1878. [PMID: 29716942 PMCID: PMC6202206 DOI: 10.1161/circulationaha.117.031788] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Hypertrophic cardiomyocyte growth and dysfunction accompany various forms of heart disease. The mechanisms responsible for transcriptional changes that affect cardiac physiology and the transition to heart failure are not well understood. The intercalated disc (ID) is a specialized intercellular junction coupling cardiomyocyte force transmission and propagation of electrical activity. The ID is gaining attention as a mechanosensitive signaling hub and hotspot for causative mutations in cardiomyopathy. METHODS Transmission electron microscopy, confocal microscopy, and single-molecule localization microscopy were used to examine changes in ID structure and protein localization in the murine and human heart. We conducted detailed cardiac functional assessment and transcriptional profiling of mice lacking myocardin-related transcription factor (MRTF)-A and MRTF-B specifically in adult cardiomyocytes to evaluate the role of mechanosensitive regulation of gene expression in load-induced ventricular remodeling. RESULTS We found that MRTFs localize to IDs in the healthy human heart and accumulate in the nucleus in heart failure. Although mice lacking MRTFs in adult cardiomyocytes display normal cardiac physiology at baseline, pressure overload leads to rapid heart failure characterized by sarcomere disarray, ID disintegration, chamber dilation and wall thinning, cardiac functional decline, and partially penetrant acute lethality. Transcriptional profiling reveals a program of actin cytoskeleton and cardiomyocyte adhesion genes driven by MRTFs during pressure overload. Indeed, conspicuous remodeling of gap junctions at IDs identified by single-molecule localization microscopy may partially stem from a reduction in Mapre1 expression, which we show is a direct mechanosensitive MRTF target. CONCLUSIONS Our study describes a novel paradigm in which MRTFs control an acute mechanosensitive signaling circuit that coordinates cross-talk between the actin and microtubule cytoskeleton and maintains ID integrity and cardiomyocyte homeostasis in heart disease.
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MESH Headings
- Aged
- Animals
- Animals, Newborn
- COS Cells
- Case-Control Studies
- Chlorocebus aethiops
- Connexin 43/genetics
- Connexin 43/metabolism
- Female
- Gene Expression Regulation
- Heart Failure/genetics
- Heart Failure/metabolism
- Heart Failure/pathology
- Heart Failure/physiopathology
- Humans
- Hypertrophy, Left Ventricular/genetics
- Hypertrophy, Left Ventricular/metabolism
- Hypertrophy, Left Ventricular/pathology
- Hypertrophy, Left Ventricular/physiopathology
- Male
- Mechanotransduction, Cellular
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Microscopy, Confocal
- Microscopy, Electron, Transmission
- Microtubule-Associated Proteins/genetics
- Microtubule-Associated Proteins/metabolism
- Middle Aged
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/ultrastructure
- NIH 3T3 Cells
- Single Molecule Imaging
- Trans-Activators/deficiency
- Trans-Activators/genetics
- Trans-Activators/metabolism
- Transcription Factors/deficiency
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Ventricular Function, Left
- Ventricular Remodeling
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Affiliation(s)
- Michael A. Trembley
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, NY
| | - Pearl Quijada
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, NY
| | - Esperanza Agullo-Pascual
- The Leon H Charney Division of Cardiology, Department of Medicine, New York University School of Medicine, New York, NY
| | - Kevin M. Tylock
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY
| | - Mert Colpan
- Department of Cellular and Molecular Medicine, Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ
| | - Ronald A. Dirkx
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, NY
| | - Jason R. Myers
- Genomics Research Center, University of Rochester, Rochester, NY
| | - Deanne M. Mickelsen
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, NY
| | | | - Eli Rothenberg
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY
| | | | - Jeffrey D. Alexis
- Division of Cardiology, Department of Medicine, University of Rochester, Rochester, NY
| | - Carol C. Gregorio
- Department of Cellular and Molecular Medicine, Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ
| | - Robert T. Dirksen
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY
| | - Mario Delmar
- The Leon H Charney Division of Cardiology, Department of Medicine, New York University School of Medicine, New York, NY
| | - Eric M. Small
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, NY
- Department of Biomedical Engineering, University of Rochester, Rochester, NY
- Author for correspondence: Eric M. Small, Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Box CVRI, Rochester, NY 14642, Phone: (585)276-7706, Fax: (585) 276-9839,
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4
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Guo Y, Jardin BD, Zhou P, Sethi I, Akerberg BN, Toepfer CN, Ai Y, Li Y, Ma Q, Guatimosim S, Hu Y, Varuzhanyan G, VanDusen NJ, Zhang D, Chan DC, Yuan GC, Seidman CE, Seidman JG, Pu WT. Hierarchical and stage-specific regulation of murine cardiomyocyte maturation by serum response factor. Nat Commun 2018; 9:3837. [PMID: 30242271 PMCID: PMC6155060 DOI: 10.1038/s41467-018-06347-2] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 08/30/2018] [Indexed: 02/06/2023] Open
Abstract
After birth, cardiomyocytes (CM) acquire numerous adaptations in order to efficiently pump blood throughout an animal's lifespan. How this maturation process is regulated and coordinated is poorly understood. Here, we perform a CRISPR/Cas9 screen in mice and identify serum response factor (SRF) as a key regulator of CM maturation. Mosaic SRF depletion in neonatal CMs disrupts many aspects of their maturation, including sarcomere expansion, mitochondrial biogenesis, transverse-tubule formation, and cellular hypertrophy. Maintenance of maturity in adult CMs is less dependent on SRF. This stage-specific activity is associated with developmentally regulated SRF chromatin occupancy and transcriptional regulation. SRF directly activates genes that regulate sarcomere assembly and mitochondrial dynamics. Perturbation of sarcomere assembly but not mitochondrial dynamics recapitulates SRF knockout phenotypes. SRF overexpression also perturbs CM maturation. Together, these data indicate that carefully balanced SRF activity is essential to promote CM maturation through a hierarchy of cellular processes orchestrated by sarcomere assembly.
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Affiliation(s)
- Yuxuan Guo
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Blake D Jardin
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA, 02215, USA
| | - Pingzhu Zhou
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Isha Sethi
- Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA, 02215, USA
| | - Brynn N Akerberg
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Christopher N Toepfer
- Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA, 02115, USA
- Radcliffe Department of Medicine and Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK
| | - Yulan Ai
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Yifei Li
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
- Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, 610041, Chengdu, Sichuan, China
| | - Qing Ma
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Silvia Guatimosim
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Belo Horizonte, MG, CEP: 31270-901, Brazil
| | - Yongwu Hu
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
- Wenzhou Medical University, School of Life Sciences, Wenzhou, China
| | - Grigor Varuzhanyan
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 East California Boulevard, MC 114-96, Pasadena, CA, 91125, USA
| | - Nathan J VanDusen
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Donghui Zhang
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA
- Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, 430062, Wuhan, China
| | - David C Chan
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 East California Boulevard, MC 114-96, Pasadena, CA, 91125, USA
| | - Guo-Cheng Yuan
- Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA, 02215, USA
| | - Christine E Seidman
- Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA, 02115, USA
- Division of Cardiovascular Medicine, Brigham and Women's Hospital, 75 Francis Street, Boston, MA, 02115, USA
- Howard Hughes Medical Institute, 4000 Jones Bridge Road, Chevy Chase, MD, 20815, USA
| | - Jonathan G Seidman
- Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA, 02115, USA
| | - William T Pu
- Department of Cardiology, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115, USA.
- Harvard Stem Cell Institute, 7 Divinity Avenue, Cambridge, MA, 02138, USA.
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5
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Fan TP, Ting HC, Yu JK, Su YH. Reiterative use of FGF signaling in mesoderm development during embryogenesis and metamorphosis in the hemichordate Ptychodera flava. BMC Evol Biol 2018; 18:120. [PMID: 30075704 PMCID: PMC6091094 DOI: 10.1186/s12862-018-1235-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 07/26/2018] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Mesoderm is generally considered to be a germ layer that is unique to Bilateria, and it develops into diverse tissues, including muscle, and in the case of vertebrates, the skeleton and notochord. Studies on various deuterostome animals have demonstrated that fibroblast growth factor (FGF) signaling is required for the formation of many mesodermal structures, such as vertebrate somites, from which muscles are differentiated, and muscles in sea urchin embryos, suggesting an ancient role of FGF signaling in muscle development. However, the formation of trunk muscles in invertebrate chordates is FGF-independent, leading to ambiguity about this ancient role in deuterostomes. To further understand the role of FGF signaling during deuterostome evolution, we investigated the development of mesodermal structures during embryogenesis and metamorphosis in Ptychodera flava, an indirect-developing hemichordate that has larval morphology similar to echinoderms and adult body features that are similar to chordates. RESULTS Here we show that genes encoding FGF ligands, FGF receptors and transcription factors that are known to be involved in mesoderm formation and myogenesis are expressed dynamically during embryogenesis and metamorphosis. FGF signaling at the early gastrula stage is required for the specification of the mesodermal cell fate in P. flava. The mesoderm cells are then differentiated stepwise into the hydroporic canal, the pharyngeal muscle and the muscle string; formation of the last two muscular structures are controlled by FGF signaling. Moreover, augmentation of FGF signaling during metamorphosis accelerated the process, facilitating the transformation from cilia-driven swimming larvae into muscle-driven worm-like juveniles. CONCLUSIONS Our data show that FGF signaling is required for mesoderm induction and myogenesis in the P. flava embryo, and it is reiteratively used for the morphological transition during metamorphosis. The dependence of muscle development on FGF signaling in both planktonic larvae and sand-burrowing worms supports its ancestral role in deuterostomes.
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Affiliation(s)
- Tzu-Pei Fan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, National Chung Hsing University and Academia Sinica, Taipei, 11529, Taiwan.,Institute of Cellular and Organismic Biology, Academia Sinica, 128 Academia Rd., Sec. 2, Nankang, Taipei, 11529, Taiwan.,Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Hsiu-Chi Ting
- Institute of Cellular and Organismic Biology, Academia Sinica, 128 Academia Rd., Sec. 2, Nankang, Taipei, 11529, Taiwan
| | - Jr-Kai Yu
- Institute of Cellular and Organismic Biology, Academia Sinica, 128 Academia Rd., Sec. 2, Nankang, Taipei, 11529, Taiwan
| | - Yi-Hsien Su
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, National Chung Hsing University and Academia Sinica, Taipei, 11529, Taiwan. .,Institute of Cellular and Organismic Biology, Academia Sinica, 128 Academia Rd., Sec. 2, Nankang, Taipei, 11529, Taiwan. .,Biotechnology Center, National Chung Hsing University, Taichung, 40227, Taiwan.
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6
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Xiang Y, Liao XH, Li JP, Li H, Qin H, Yao A, Yu CX, Hu P, Guo W, Gu CJ, Zhang TC. Myocardin and Stat3 act synergistically to inhibit cardiomyocyte apoptosis. Oncotarget 2017; 8:99612-99623. [PMID: 29245928 PMCID: PMC5725119 DOI: 10.18632/oncotarget.20450] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 07/26/2017] [Indexed: 02/07/2023] Open
Abstract
Signal transducer and activator of transcription 3 (Stat3) and Myocardin regulate cardiomyocyte differentiation, proliferation, and apoptosis. We report a novel aspect of the cellular function of Myocardin and Stat3 in the regulation of cardiomyocyte apoptosis. Myocardin and Stat3 showed anti-apoptotic function by increasing the expression of Bcl-2 while reducing expression of the pro-apoptotic genes Bax, Apaf-1, caspase-9, and caspase-3. Moreover, myocardin/Stat3-mediated activation of Bcl-2 and Mcl-1 transcription is contingent on the CArG box. Myocardin and Stat3 synergistically inhibited staurosporine-induced cardiomyocyte apoptosis by up-regulating expression of anti-apoptotic Bcl-2 and Mcl-1 in neonatal rat cardiomyocytes. These results describe a novel anti-apoptotic Myocardin/Stat3 signaling pathway operating during cardiomyocyte apoptosis. This provides a molecular explanation for cardiomyocyte apoptosis inhibition as a critical component of myocardial protection.
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Affiliation(s)
- Yuan Xiang
- Institute of Biology and Medicine, Wuhan University of Science and Technology, Hubei, 430081, P.R. China
| | - Xing-Hua Liao
- Institute of Biology and Medicine, Wuhan University of Science and Technology, Hubei, 430081, P.R. China
| | - Jia-Peng Li
- Institute of Biology and Medicine, Wuhan University of Science and Technology, Hubei, 430081, P.R. China
| | - Hui Li
- Institute of Biology and Medicine, Wuhan University of Science and Technology, Hubei, 430081, P.R. China
| | - Huan Qin
- Institute of Biology and Medicine, Wuhan University of Science and Technology, Hubei, 430081, P.R. China
| | - Ao Yao
- Institute of Biology and Medicine, Wuhan University of Science and Technology, Hubei, 430081, P.R. China
| | - Cheng-Xi Yu
- Institute of Biology and Medicine, Wuhan University of Science and Technology, Hubei, 430081, P.R. China
| | - Peng Hu
- Institute of Biology and Medicine, Wuhan University of Science and Technology, Hubei, 430081, P.R. China
| | - Wei Guo
- Shenzhen Ritzcon Biological Technology Co., LTD, Shenzhen, Guangdong, 518000, P.R. China
| | - Chao-Jiang Gu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education and Tianjin, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, P.R. China
| | - Tong-Cun Zhang
- Institute of Biology and Medicine, Wuhan University of Science and Technology, Hubei, 430081, P.R. China.,Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education and Tianjin, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, P.R. China
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7
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Eroshkin FM, Zaraisky AG. Mechano-sensitive regulation of gene expression during the embryonic development. Genesis 2017; 55. [PMID: 28236362 DOI: 10.1002/dvg.23026] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 02/06/2017] [Accepted: 02/20/2017] [Indexed: 12/14/2022]
Abstract
Cell movements during embryogenesis produce mechanical tensions that shape the embryo and can also regulate gene expression, thereby affecting cell differentiation. Increasing evidence indicates that mechanosensitive regulation of gene expression plays important roles during embryogenesis by coupling the processes of morphogenesis and differentiation. However, the molecular mechanisms of this phenomenon remain poorly understood. This review focuses on the molecular mechanisms that "translate" mechanical stimuli into gene expression.
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Affiliation(s)
- Fedor M Eroshkin
- Laboratory of Molecular Bases of Embryogenesis, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Andrey G Zaraisky
- Laboratory of Molecular Bases of Embryogenesis, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
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8
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Kaymak A, Richly H. Zrf1 controls mesoderm lineage genes and cardiomyocyte differentiation. Cell Cycle 2016; 15:3306-3317. [PMID: 27754813 DOI: 10.1080/15384101.2016.1245246] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
In the present study we addressed the function of the transcriptional activator Zrf1 in the generation of the 3 germ layers during in vitro development. Currently, Zrf1 is rather regarded as a factor that drives the expression of neuronal genes. Here, we have employed mouse embryonic stem cells and P19 cells to understand the role of Zrf1 in the generation of mesoderm-derived tissues like adipocytes, cartilage and heart. Our data shows that Zrf1 is essential for the transcriptional activation of genes that give rise to mesoderm and in particular heart development. In both, the mESC and P19 systems, we provide evidence that Zrf1 contributes to the generation of functional cardiomyocytes. We further demonstrate that Zrf1 binds to the transcription start sites (TSSs) of heart tissue-specific genes from the first and second heart field where it drives their temporal expression during differentiation. Taken together, we have identified Zrf1 as a novel regulator of the mesodermal lineage that might facilitate spatiotemporal expression of genes.
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Affiliation(s)
- Aysegül Kaymak
- a Laboratory of Molecular Epigenetics, Institute of Molecular Biology (IMB) , Mainz , Germany.,b Faculty of Biology, Johannes Gutenberg University , Mainz , Germany
| | - Holger Richly
- a Laboratory of Molecular Epigenetics, Institute of Molecular Biology (IMB) , Mainz , Germany
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9
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Lighthouse JK, Small EM. Transcriptional control of cardiac fibroblast plasticity. J Mol Cell Cardiol 2016; 91:52-60. [PMID: 26721596 PMCID: PMC4764462 DOI: 10.1016/j.yjmcc.2015.12.016] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 12/15/2015] [Accepted: 12/20/2015] [Indexed: 12/11/2022]
Abstract
Cardiac fibroblasts help maintain the normal architecture of the healthy heart and are responsible for scar formation and the healing response to pathological insults. Various genetic, biomechanical, or humoral factors stimulate fibroblasts to become contractile smooth muscle-like cells called myofibroblasts that secrete large amounts of extracellular matrix. Unfortunately, unchecked myofibroblast activation in heart disease leads to pathological fibrosis, which is a major risk factor for the development of cardiac arrhythmias and heart failure. A better understanding of the molecular mechanisms that control fibroblast plasticity and myofibroblast activation is essential to develop novel strategies to specifically target pathological cardiac fibrosis without disrupting the adaptive healing response. This review highlights the major transcriptional mediators of fibroblast origin and function in development and disease. The contribution of the fetal epicardial gene program will be discussed in the context of fibroblast origin in development and following injury, primarily focusing on Tcf21 and C/EBP. We will also highlight the major transcriptional regulatory axes that control fibroblast plasticity in the adult heart, including transforming growth factor β (TGFβ)/Smad signaling, the Rho/myocardin-related transcription factor (MRTF)/serum response factor (SRF) axis, and Calcineurin/transient receptor potential channel (TRP)/nuclear factor of activated T-Cell (NFAT) signaling. Finally, we will discuss recent strategies to divert the fibroblast transcriptional program in an effort to promote cardiomyocyte regeneration. This article is a part of a Special Issue entitled "Fibrosis and Myocardial Remodeling".
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Affiliation(s)
- Janet K Lighthouse
- Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, Rochester, NY 14624, USA
| | - Eric M Small
- Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY 14624, USA; Department of Pharmacology and Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14624, USA; Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, Rochester, NY 14624, USA.
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10
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Forward Programming of Cardiac Stem Cells by Homogeneous Transduction with MYOCD plus TBX5. PLoS One 2015; 10:e0125384. [PMID: 26047103 PMCID: PMC4457652 DOI: 10.1371/journal.pone.0125384] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 03/23/2015] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED Adult cardiac stem cells (CSCs) express many endogenous cardiogenic transcription factors including members of the Gata, Hand, Mef2, and T-box family. Unlike its DNA-binding targets, Myocardin (Myocd)-a co-activator not only for serum response factor, but also for Gata4 and Tbx5-is not expressed in CSCs. We hypothesised that its absence was a limiting factor for reprogramming. Here, we sought to investigate the susceptibility of adult mouse Sca1+ side population CSCs to reprogramming by supplementing the triad of GATA4, MEF2C, and TBX5 (GMT), and more specifically by testing the effect of the missing co-activator, Myocd. Exogenous factors were expressed via doxycycline-inducible lentiviral vectors in various combinations. High throughput quantitative RT-PCR was used to test expression of 29 cardiac lineage markers two weeks post-induction. GMT induced more than half the analysed cardiac transcripts. However, no protein was detected for the induced sarcomeric genes Actc1, Myh6, and Myl2. Adding MYOCD to GMT affected only slightly the breadth and level of gene induction, but, importantly, triggered expression of all three proteins examined (α-cardiac actin, atrial natriuretic peptide, sarcomeric myosin heavy chains). MYOCD + TBX was the most effective pairwise combination in this system. In clonal derivatives homogenously expressing MYOCD + TBX at high levels, 93% of cardiac transcripts were up-regulated and all five proteins tested were visualized. IN SUMMARY (1) GMT induced cardiac genes in CSCs, but not cardiac proteins under the conditions used. (2) Complementing GMT with MYOCD induced cardiac protein expression, indicating a more complete cardiac differentiation program. (3) Homogeneous transduction with MYOCD + TBX5 facilitated the identification of differentiating cells and the validation of this combinatorial reprogramming strategy. Together, these results highlight the pivotal importance of MYOCD in driving CSCs toward a cardiac muscle fate.
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11
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Abstract
Myocardin (MYOCD) is a potent transcriptional coactivator that functions primarily in cardiac muscle and smooth muscle through direct contacts with serum response factor (SRF) over cis elements known as CArG boxes found near a number of genes encoding for contractile, ion channel, cytoskeletal, and calcium handling proteins. Since its discovery more than 10 years ago, new insights have been obtained regarding the diverse isoforms of MYOCD expressed in cells as well as the regulation of MYOCD expression and activity through transcriptional, post-transcriptional, and post-translational processes. Curiously, there are a number of functions associated with MYOCD that appear to be independent of contractile gene expression and the CArG-SRF nucleoprotein complex. Further, perturbations in MYOCD gene expression are associated with an increasing number of diseases including heart failure, cancer, acute vessel disease, and diabetes. This review summarizes the various biological and pathological processes associated with MYOCD and offers perspectives to several challenges and future directions for further study of this formidable transcriptional coactivator.
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Affiliation(s)
- Joseph M Miano
- Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
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12
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Zhang J, Ho JCY, Chan YC, Lian Q, Siu CW, Tse HF. Overexpression of myocardin induces partial transdifferentiation of human-induced pluripotent stem cell-derived mesenchymal stem cells into cardiomyocytes. Physiol Rep 2014; 2:e00237. [PMID: 24744906 PMCID: PMC3966242 DOI: 10.1002/phy2.237] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 01/21/2014] [Accepted: 01/26/2014] [Indexed: 12/13/2022] Open
Abstract
Mesenchymal stem cells (MSCs) derived from human‐induced pluripotent stem cells (iPSCs) show superior proliferative capacity and therapeutic potential than those derived from bone marrow (BM). Ectopic expression of myocardin further improved the therapeutic potential of BM‐MSCs in a mouse model of myocardial infarction. The aim was of this study was to assess whether forced myocardin expression in iPSC‐MSCs could further enhance their transdifferentiation to cardiomyocytes and improve their electrophysiological properties for cardiac regeneration. Myocardin was overexpressed in iPSC‐MSCs using viral vectors (adenovirus or lentivirus). The expression of smooth muscle cell and cardiomyocyte markers, and ion channel genes was examined by reverse transcription‐polymerase chain reaction (RT‐PCR), immunofluorescence staining and patch clamp. The conduction velocity of the neonatal rat ventricular cardiomyocytes cocultured with iPSC‐MSC monolayer was measured by multielectrode arrays recording plate. Myocardin induced the expression of α‐MHC, GATA4, α‐actinin, cardiac MHC, MYH11, calponin, and SM α‐actin, but not cTnT, β‐MHC, and MLC2v in iPSC‐MSCs. Overexpression of myocardin in iPSC‐MSC enhanced the expression of SCN9A and CACNA1C, but reduced that of KCa3.1 and Kir2.2 in iPSC‐MSCs. Moreover, BKCa, IKir, ICl, Ito and INa.TTX were detected in iPSC‐MSC with myocardin overexpression; while only BKCa, IKir, ICl, IKDR, and IKCa were noted in iPSC‐MSC transfected with green florescence protein. Furthermore, the conduction velocity of iPSC‐MSC was significantly increased after myocardin overexpression. Overexpression of myocardin in iPSC‐MSCs resulted in partial transdifferentiation into cardiomyocytes phenotype and improved the electrical conduction during integration with mature cardiomyocytes. Forced myocardin expression in human‐induced pluripotent stem cell (hiPSC)‐derived mesenchymal stem cells lead to partial transdifferentiation into cardiomyocytes and smooth muscle cells phenotypes through modification in ion channel expression profile and electrical conduction velocity.
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Affiliation(s)
- Jiao Zhang
- Division of Cardiology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China
| | - Jenny Chung-Yee Ho
- Division of Cardiology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China ; Research Centre of Heart, Brain, Hormone & Healthy Aging, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Yau-Chi Chan
- Division of Cardiology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China
| | - Qizhou Lian
- Division of Cardiology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China ; Research Centre of Heart, Brain, Hormone & Healthy Aging, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China ; Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Chung-Wah Siu
- Division of Cardiology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China ; Research Centre of Heart, Brain, Hormone & Healthy Aging, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Hung-Fat Tse
- Division of Cardiology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China ; Research Centre of Heart, Brain, Hormone & Healthy Aging, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
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13
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Zhou S, Liu Y, Prater K, Zheng Y, Cai L. Roles of microRNAs in pressure overload- and ischemia-related myocardial remodeling. Life Sci 2013; 93:855-862. [PMID: 24021888 DOI: 10.1016/j.lfs.2013.08.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 08/21/2013] [Accepted: 08/29/2013] [Indexed: 12/11/2022]
Abstract
Cardiac remodeling, a term that spans maladaptation at the molecular, cellular, tissue and organ levels, is the key pathophysiological process that leads to heart failure (HF). In clinic, pressure overload and ischemia are the two most common reasons to induce cardiac remodeling and HF, which includes but is not limited to cardiac hypertrophy, fibrosis, and cardiomyocyte apoptosis. MicroRNAs (miRNAs) are endogenous, single-stranded, short non-coding RNAs. By imperfectly binding to the 3' untranslated region (UTR) of messenger RNAs (mRNAs), miRNAs are able to suppress target gene expression by promoting degradation or by inhibiting translation of the target mRNAs, thus playing an important role in a wide range of biologic processes. Growing evidence has indicated that miRNAs are aberrantly expressed in the cardiovascular system under experimental and clinical conditions with cardiac remodeling and HF. Clinically there is increasing evidence that miRNAs can act as diagnostic biomarker and even represent a novel therapeutic target in several cardiovascular disorders. This review provides an overview of several miRNAs' impacts in pressure-overload and ischemia-induced cardiac remodeling and HF.
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Affiliation(s)
- Shanshan Zhou
- The Cardiovascular Center, The First Hospital of Jilin University, Changchun, China; Kosair Children's Hospital Research Institute, Department of Pediatrics, University of Louisville, Louisville, KY, USA
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Transcriptional networks regulating the costamere, sarcomere, and other cytoskeletal structures in striated muscle. Cell Mol Life Sci 2013; 71:1641-56. [PMID: 24218011 DOI: 10.1007/s00018-013-1512-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 10/27/2013] [Accepted: 10/30/2013] [Indexed: 10/26/2022]
Abstract
Structural abnormalities in striated muscle have been observed in numerous transcription factor gain- and loss-of-function phenotypes in animal and cell culture model systems, indicating that transcription is important in regulating the cytoarchitecture. While most characterized cytoarchitectural defects are largely indistinguishable by histological and ultrastructural criteria, analysis of dysregulated gene expression in each mutant phenotype has yielded valuable information regarding specific structural gene programs that may be uniquely controlled by each of these transcription factors. Linking the formation and maintenance of each subcellular structure or subset of proteins within a cytoskeletal compartment to an overlapping but distinct transcription factor cohort may enable striated muscle to control cytoarchitectural function in an efficient and specific manner. Here we summarize the available evidence that connects transcription factors, those with established roles in striated muscle such as MEF2 and SRF, as well as other non-muscle transcription factors, to the regulation of a defined cytoskeletal structure. The notion that genes encoding proteins localized to the same subcellular compartment are coordinately transcriptionally regulated may prompt rationally designed approaches that target specific transcription factor pathways to correct structural defects in muscle disease.
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15
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Reil M, Dabauvalle MC. Essential roles of LEM-domain protein MAN1 during organogenesis in Xenopus laevis and overlapping functions of emerin. Eur J Cell Biol 2013; 92:280-94. [PMID: 24252515 DOI: 10.1016/j.ejcb.2013.10.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 10/23/2013] [Accepted: 10/25/2013] [Indexed: 11/26/2022] Open
Abstract
Mutations in nuclear envelope proteins are linked to an increasing number of human diseases, called envelopathies. Mutations in the inner nuclear membrane protein emerin lead to X-linked Emery-Dreifuss muscular dystrophy, characterized by muscle weakness or wasting. Conversely, mutations in nuclear envelope protein MAN1 are linked to bone and skin disorders. Both proteins share a highly conserved domain, called LEM-domain. LEM proteins are known to interact with Barrier-to-autointegration factor and several transcription factors. Most envelopathies are tissue-specific, but knowledge on the physiological roles of related LEM proteins is still unclear. For this reason, we investigated the roles of MAN1 and emerin during Xenopus laevis organogenesis. Morpholino-mediated knockdown of MAN1 revealed that MAN1 is essential for the formation of eye, skeletal and cardiac muscle tissues. The MAN1 knockdown could be compensated by ectopic expression of emerin, leading to a proper organ development. Further investigations revealed that MAN1 is involved in regulation of genes essential for organ development and tissue homeostasis. Thereby our work supports that LEM proteins might be involved in signalling essential for organ development during early embryogenesis and suggests that loss of MAN1 may cause muscle and retina specific diseases.
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Affiliation(s)
- Michael Reil
- Division of Electron Microscopy, Biocenter, University of Wuerzburg, Am Hubland, 97074 Wuerzburg, Germany.
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16
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Luo XG, Zhang CL, Zhao WW, Liu ZP, Liu L, Mu A, Guo S, Wang N, Zhou H, Zhang TC. Histone methyltransferase SMYD3 promotes MRTF-A-mediated transactivation of MYL9 and migration of MCF-7 breast cancer cells. Cancer Lett 2013; 344:129-137. [PMID: 24189459 DOI: 10.1016/j.canlet.2013.10.026] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Revised: 10/20/2013] [Accepted: 10/24/2013] [Indexed: 01/06/2023]
Abstract
Myocardin-related transcription factor-A (MRTF-A) is a Rho signal-responsive transcriptional coactivator of serum response factor (SRF). Recent studies indicated that MRTF-A might be an important regulator of mammary gland and be involved in cancer metastasis. However, the roles of histone modification in the MRTF-A-dependent signal pathway and tumor migration are still not very clear. Here, we report that histone methylation is required for the MRTF-A-mediated upregulation of myosin regulatory light chain 9 (MYL9), an important cytoskeletal component which is implicated in cell migration. Furthermore, we demonstrate that SET and MYND domain containing protein 3 (SMYD3), a hitone methyltransferase (HMT) associated with carcinogenesis, might be the one which is responsible for the histone methylation occurred in the MRTF-A-mediated- transactivation of MYL9 and migration of breast cancer cells. Overexpression of SMYD3 promotes MRTF-A-mediated upregulation of MYL9 and migration of MCF-7 breast cancer cells, while contrary results were observed when the endogenous MRTF-A and SMYD3 were suppressed with specific siRNAs. In addition, the mutation analysis suggested that this cooperative transactivation is mainly mediated via the proximal binding element of MRTF-A in the promoter of MYL9, and the HMT activity of SMYD3 is required as well. Our findings reveal a new mechanism by which MRTF-A and SMYD3 functions in transcriptional regulation and cell migration, and provide a better understanding for metastasis of breast cancer.
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Affiliation(s)
- Xue-Gang Luo
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin 300457, China.
| | - Chun-Ling Zhang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin 300457, China
| | - Wen-Wen Zhao
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin 300457, China
| | - Zhi-Peng Liu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin 300457, China
| | - Lei Liu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin 300457, China
| | - Ai Mu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin 300457, China
| | - Shu Guo
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin 300457, China
| | - Nan Wang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin 300457, China
| | - Hao Zhou
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin 300457, China
| | - Tong-Cun Zhang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin 300457, China; School of Medicine, Wuhan University of Science and Technology, Wuhan 430081, China.
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17
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Johnson AN, Mokalled MH, Valera JM, Poss KD, Olson EN. Post-transcriptional regulation of myotube elongation and myogenesis by Hoi Polloi. Development 2013; 140:3645-56. [PMID: 23942517 DOI: 10.1242/dev.095596] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Striated muscle development requires the coordinated expression of genes involved in sarcomere formation and contractility, as well as genes that determine muscle morphology. However, relatively little is known about the molecular mechanisms that control the early stages of muscle morphogenesis. To explore this facet of myogenesis, we performed a genetic screen for regulators of somatic muscle morphology in Drosophila, and identified the putative RNA-binding protein (RBP) Hoi Polloi (Hoip). Hoip is expressed in striated muscle precursors within the muscle lineage and controls two genetically separable events: myotube elongation and sarcomeric protein expression. Myotubes fail to elongate in hoip mutant embryos, even though the known regulators of somatic muscle elongation, target recognition and muscle attachment are expressed normally. In addition, a majority of sarcomeric proteins, including Myosin Heavy Chain (MHC) and Tropomyosin, require Hoip for their expression. A transgenic MHC construct that contains the endogenous MHC promoter and a spliced open reading frame rescues MHC protein expression in hoip embryos, demonstrating the involvement of Hoip in pre-mRNA splicing, but not in transcription, of muscle structural genes. In addition, the human Hoip ortholog NHP2L1 rescues muscle defects in hoip embryos, and knockdown of endogenous nhp2l1 in zebrafish disrupts skeletal muscle development. We conclude that Hoip is a conserved, post-transcriptional regulator of muscle morphogenesis and structural gene expression.
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Affiliation(s)
- Aaron N Johnson
- Department of Molecular Biology, University of Texas Southwestern Medical Center at Dallas, TX 75390-9148, USA.
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18
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Activation of MRTF-A-dependent gene expression with a small molecule promotes myofibroblast differentiation and wound healing. Proc Natl Acad Sci U S A 2013; 110:16850-5. [PMID: 24082095 DOI: 10.1073/pnas.1316764110] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Myocardin-related transcription factors (MRTFs) regulate cellular contractility and motility by associating with serum response factor (SRF) and activating genes involved in cytoskeletal dynamics. We reported previously that MRTF-A contributes to pathological cardiac remodeling by promoting differentiation of fibroblasts to myofibroblasts following myocardial infarction. Here, we show that forced expression of MRTF-A in dermal fibroblasts stimulates contraction of a collagen matrix, whereas contractility of MRTF-A null fibroblasts is impaired under basal conditions and in response to TGF-β1 stimulation. We also identify an isoxazole ring-containing small molecule, previously shown to induce smooth muscle α-actin gene expression in cardiac progenitor cells, as an agonist of myofibroblast differentiation. Isoxazole stimulates myofibroblast differentiation via induction of MRTF-A-dependent gene expression. The MRTF-SRF signaling axis is activated in response to skin injury, and treatment of dermal wounds with isoxazole accelerates wound closure and suppresses the inflammatory response. These results reveal an important role for MRTF-SRF signaling in dermal myofibroblast differentiation and wound healing and suggest that targeting MRTFs pharmacologically may prove useful in treating diseases associated with inappropriate myofibroblast activity.
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19
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Christoforou N, Chellappan M, Adler AF, Kirkton RD, Wu T, Addis RC, Bursac N, Leong KW. Transcription factors MYOCD, SRF, Mesp1 and SMARCD3 enhance the cardio-inducing effect of GATA4, TBX5, and MEF2C during direct cellular reprogramming. PLoS One 2013; 8:e63577. [PMID: 23704920 PMCID: PMC3660533 DOI: 10.1371/journal.pone.0063577] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 04/04/2013] [Indexed: 01/14/2023] Open
Abstract
Transient overexpression of defined combinations of master regulator genes can effectively induce cellular reprogramming: the acquisition of an alternative predicted phenotype from a differentiated cell lineage. This can be of particular importance in cardiac regenerative medicine wherein the heart lacks the capacity to heal itself, but simultaneously contains a large pool of fibroblasts. In this study we determined the cardio-inducing capacity of ten transcription factors to actuate cellular reprogramming of mouse embryonic fibroblasts into cardiomyocyte-like cells. Overexpression of transcription factors MYOCD and SRF alone or in conjunction with Mesp1 and SMARCD3 enhanced the basal but necessary cardio-inducing effect of the previously reported GATA4, TBX5, and MEF2C. In particular, combinations of five or seven transcription factors enhanced the activation of cardiac reporter vectors, and induced an upregulation of cardiac-specific genes. Global gene expression analysis also demonstrated a significantly greater cardio-inducing effect when the transcription factors MYOCD and SRF were used. Detection of cross-striated cells was highly dependent on the cell culture conditions and was enhanced by the addition of valproic acid and JAK inhibitor. Although we detected Ca2+ transient oscillations in the reprogrammed cells, we did not detect significant changes in resting membrane potential or spontaneously contracting cells. This study further elucidates the cardio-inducing effect of the transcriptional networks involved in cardiac cellular reprogramming, contributing to the ongoing rational design of a robust protocol required for cardiac regenerative therapies.
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Affiliation(s)
- Nicolas Christoforou
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America
| | - Malathi Chellappan
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America
| | - Andrew F. Adler
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America
| | - Robert D. Kirkton
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America
| | - Tianyi Wu
- University of Texas Southwestern Medical School, Dallas, Texas, United States of America
| | - Russell C. Addis
- Institute for Regenerative Medicine and Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Nenad Bursac
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America
| | - Kam W. Leong
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America
- * E-mail:
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20
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Cao D, Wang C, Tang R, Chen H, Zhang Z, Tatsuguchi M, Wang DZ. Acetylation of myocardin is required for the activation of cardiac and smooth muscle genes. J Biol Chem 2012; 287:38495-504. [PMID: 23007391 DOI: 10.1074/jbc.m112.353649] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Myocardin belongs to the SAF-A/B, Acinus, PIAS (SAP) domain family of transcription factors and is specifically expressed in cardiac and smooth muscle. Myocardin functions as a transcriptional coactivator of SRF and is sufficient and necessary for smooth muscle gene expression. We have previously found that myocardin induces the acetylation of nucleosomal histones surrounding SRF-binding sites in the control regions of cardiac and smooth muscle genes through recruiting chromatin-modifying enzyme p300, yet no studies have determined whether myocardin itself is similarly modified. In this study, we show that myocardin is a direct target for p300-mediated acetylation. p300 acetylates lysine residues at the N terminus of the myocardin protein. Interestingly, a direct interaction between p300 and myocardin, which is mediated by the C terminus of myocardin, is required for the acetylation event. Acetylation of myocardin by p300 enhances the association of myocardin and SRF as well as the formation of the myocardin-SRF-CArG box ternary complex. Conversely, acetylation of myocardin decreases the binding of histone deacetylase 5 (HDAC5) to myocardin. Acetylation of myocardin is required for myocardin to activate smooth muscle genes. Our study demonstrates that acetylation plays a key role in modulating myocardin function in controlling cardiac and smooth muscle gene expression.
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Affiliation(s)
- Dongsun Cao
- Department of Cardiology, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts 02115, USA
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21
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Huang J, Elicker J, Bowens N, Liu X, Cheng L, Cappola TP, Zhu X, Parmacek MS. Myocardin regulates BMP10 expression and is required for heart development. J Clin Invest 2012; 122:3678-91. [PMID: 22996691 DOI: 10.1172/jci63635] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 07/26/2012] [Indexed: 01/12/2023] Open
Abstract
Myocardin is a muscle lineage-restricted transcriptional coactivator that has been shown to transduce extracellular signals to the nucleus required for SMC differentiation. We now report the discovery of a myocardin/BMP10 (where BMP10 indicates bone morphogenetic protein 10) signaling pathway required for cardiac growth, chamber maturation, and embryonic survival. Myocardin-null (Myocd) embryos and embryos harboring a cardiomyocyte-restricted mutation in the Myocd gene exhibited myocardial hypoplasia, defective atrial and ventricular chamber maturation, heart failure, and embryonic lethality. Cardiac hypoplasia was caused by decreased cardiomyocyte proliferation accompanied by a dramatic increase in programmed cell death. Defective chamber maturation and the block in cardiomyocyte proliferation were caused in part by a block in BMP10 signaling. Myocardin transactivated the Bmp10 gene via binding of a serum response factor-myocardin protein complex to a nonconsensus CArG element in the Bmp10 promoter. Expression of p57kip2, a BMP10-regulated cyclin-dependent kinase inhibitor, was induced in Myocd-/- hearts, while BMP10-activated cardiogenic transcription factors, including NKX2.5 and MEF2c, were repressed. Remarkably, when embryonic Myocd-/- hearts were cultured ex vivo in BMP10-conditioned medium, the defects in cardiomyocyte proliferation and p57kip2 expression were rescued. Taken together, these data identify a heretofore undescribed myocardin/BMP10 signaling pathway that regulates cardiomyocyte proliferation and apoptosis in the embryonic heart.
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Affiliation(s)
- Jianhe Huang
- University of Pennsylvania, Cardiovascular Institute, Department of Medicine, Philadelphia, PA 19104-5159, USA
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22
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Heavy and light roles: myosin in the morphogenesis of the heart. Cell Mol Life Sci 2012; 70:1221-39. [PMID: 22955375 PMCID: PMC3602621 DOI: 10.1007/s00018-012-1131-1] [Citation(s) in RCA: 158] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 08/08/2012] [Accepted: 08/13/2012] [Indexed: 01/10/2023]
Abstract
Myosin is an essential component of cardiac muscle, from the onset of cardiogenesis through to the adult heart. Although traditionally known for its role in energy transduction and force development, recent studies suggest that both myosin heavy-chain and myosin light-chain proteins are required for a correctly formed heart. Myosins are structural proteins that are not only expressed from early stages of heart development, but when mutated in humans they may give rise to congenital heart defects. This review will discuss the roles of myosin, specifically with regards to the developing heart. The expression of each myosin protein will be described, and the effects that altering expression has on the heart in embryogenesis in different animal models will be discussed. The human molecular genetics of the myosins will also be reviewed.
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23
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Small EM. The actin-MRTF-SRF gene regulatory axis and myofibroblast differentiation. J Cardiovasc Transl Res 2012; 5:794-804. [PMID: 22898751 DOI: 10.1007/s12265-012-9397-0] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 08/01/2012] [Indexed: 12/14/2022]
Abstract
Cardiac fibroblasts are responsible for necrotic tissue replacement and scar formation after myocardial infarction (MI) and contribute to remodeling in response to pathological stimuli. This response to insult or injury is largely due to the phenotypic plasticity of fibroblasts. When fibroblasts encounter environmental disturbances, whether biomechanical or humoral, they often transform into smooth muscle-like, contractile cells called "myofibroblasts." The signals that control myofibroblast differentiation include the transforming growth factor (TGF)-β1-Smad pathway and Rho GTPase-dependent actin polymerization. Recent evidence implicates serum response factor (SRF) and the myocardin-related transcription factors (MRTFs) as key mediators of the contractile gene program in response to TGF-β1 or RhoA signaling. This review highlights the function of myofibroblasts in cardiac remodeling and the role of the actin-MRTF-SRF signaling axis in regulating this process.
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Affiliation(s)
- Eric M Small
- Aab Cardiovascular Research Institute, Department of Medicine, School of Medicine and Dentistry, University of Rochester, 601 Elmwood Avenue, Box CVRI, Rochester, NY 14642, USA.
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24
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Small changes can make a big difference — MicroRNA regulation of cardiac hypertrophy. J Mol Cell Cardiol 2012; 52:74-82. [DOI: 10.1016/j.yjmcc.2011.09.015] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 09/15/2011] [Accepted: 09/16/2011] [Indexed: 11/23/2022]
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25
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Abstract
The study of gene function in developmental biology has been significantly furthered by advances in antisense technology made in the early 2000s. This was achieved, in particular, by the introduction of morpholino (MO) oligonucleotides. The introduction of antisense MO oligonucleotides into cells enables researchers to readily reduce the levels of their protein of interest without investing huge financial or temporal resources, in both in vivo and in vitro model systems. Historically, the African clawed frog Xenopus has been used to study vertebrate embryological development, due to its ability to produce vast numbers of offspring that develop rapidly, in synchrony, and can be cultured in buffers with ease. The developmental progress of Xenopus embryos has been extensively characterized and this model organism is very easy to maintain. It is these attributes that enable MO-based knockdown strategies to be so effective in Xenopus. In this chapter, we will detail the methods of microinjecting MO oligonucleotides into early embryos of X. laevis and X. tropicalis. We will discuss how MOs can be used to prevent either pre-mRNA splicing or translation of the specific gene of interest resulting in abrogation of that gene's function and advise on what control experiments should be undertaken to verify their efficacy.
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Affiliation(s)
- Panna Tandon
- Department of Genetics, UNC McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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26
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Torrado M, Iglesias R, Centeno A, López E, Mikhailov AT. Targeted gene-silencing reveals the functional significance of myocardin signaling in the failing heart. PLoS One 2011; 6:e26392. [PMID: 22028870 PMCID: PMC3196561 DOI: 10.1371/journal.pone.0026392] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 09/26/2011] [Indexed: 12/20/2022] Open
Abstract
Background Myocardin (MYOCD), a potent transcriptional coactivator of smooth muscle (SM) and cardiac genes, is upregulated in failing myocardium in animal models and human end-stage heart failure (HF). However, the molecular and functional consequences of myocd upregulation in HF are still unclear. Methodology/Principal Findings The goal of the present study was to investigate if targeted inhibition of upregulated expression of myocd could influence failing heart gene expression and function. To this end, we used the doxorubicin (Dox)-induced diastolic HF (DHF) model in neonatal piglets, in which, as we show, not only myocd but also myocd-dependent SM-marker genes are highly activated in failing left ventricular (LV) myocardium. In this model, intra-myocardial delivery of short-hairpin RNAs, designed to target myocd variants expressed in porcine heart, leads on day 2 post-delivery to: (1) a decrease in the activated expression of myocd and myocd-dependent SM-marker genes in failing myocardium to levels seen in healthy control animals, (2) amelioration of impaired diastolic dysfunction, and (3) higher survival rates of DHF piglets. The posterior restoration of elevated myocd expression (on day 7 post-delivery) led to overexpression of myocd-dependent SM-marker genes in failing LV-myocardium that was associated with a return to altered diastolic function. Conclusions/Significance These data provide the first evidence that a moderate inhibition (e.g., normalization) of the activated MYOCD signaling in the diseased heart may be promising from a therapeutic point of view.
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Affiliation(s)
- Mario Torrado
- Developmental Biology Group, Institute of Health Sciences, University of La Coruña, La Coruña, Spain
| | - Raquel Iglesias
- Developmental Biology Group, Institute of Health Sciences, University of La Coruña, La Coruña, Spain
| | - Alberto Centeno
- Experimental Surgery Unit, University Hospital Center of La Coruña, La Coruña, Spain
| | - Eduardo López
- Experimental Surgery Unit, University Hospital Center of La Coruña, La Coruña, Spain
| | - Alexander T. Mikhailov
- Developmental Biology Group, Institute of Health Sciences, University of La Coruña, La Coruña, Spain
- * E-mail:
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27
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Kaltenbrun E, Tandon P, Amin NM, Waldron L, Showell C, Conlon FL. Xenopus: An emerging model for studying congenital heart disease. BIRTH DEFECTS RESEARCH. PART A, CLINICAL AND MOLECULAR TERATOLOGY 2011; 91:495-510. [PMID: 21538812 PMCID: PMC3125675 DOI: 10.1002/bdra.20793] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Revised: 01/18/2011] [Accepted: 01/28/2011] [Indexed: 02/02/2023]
Abstract
Congenital heart defects affect nearly 1% of all newborns and are a significant cause of infant death. Clinical studies have identified a number of congenital heart syndromes associated with mutations in genes that are involved in the complex process of cardiogenesis. The African clawed frog, Xenopus, has been instrumental in studies of vertebrate heart development and provides a valuable tool to investigate the molecular mechanisms underlying human congenital heart diseases. In this review, we discuss the methodologies that make Xenopus an ideal model system to investigate heart development and disease. We also outline congenital heart conditions linked to cardiac genes that have been well studied in Xenopus and describe some emerging technologies that will further aid in the study of these complex syndromes.
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Affiliation(s)
- Erin Kaltenbrun
- University of North Carolina McAllister Heart Institute
- Department of Biology, UNC-Chapel Hill, Chapel Hill, NC 27599
| | - Panna Tandon
- University of North Carolina McAllister Heart Institute
- Department of Genetics, UNC-Chapel Hill, Chapel Hill, NC 27599
| | - Nirav M. Amin
- University of North Carolina McAllister Heart Institute
- Department of Genetics, UNC-Chapel Hill, Chapel Hill, NC 27599
| | - Lauren Waldron
- University of North Carolina McAllister Heart Institute
- Department of Genetics, UNC-Chapel Hill, Chapel Hill, NC 27599
| | - Chris Showell
- University of North Carolina McAllister Heart Institute
- Department of Genetics, UNC-Chapel Hill, Chapel Hill, NC 27599
| | - Frank L. Conlon
- University of North Carolina McAllister Heart Institute
- Department of Biology, UNC-Chapel Hill, Chapel Hill, NC 27599
- Department of Genetics, UNC-Chapel Hill, Chapel Hill, NC 27599
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28
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Doherty JT, Lenhart KC, Cameron MV, Mack CP, Conlon FL, Taylor JM. Skeletal muscle differentiation and fusion are regulated by the BAR-containing Rho-GTPase-activating protein (Rho-GAP), GRAF1. J Biol Chem 2011; 286:25903-21. [PMID: 21622574 DOI: 10.1074/jbc.m111.243030] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Although RhoA activity is necessary for promoting myogenic mesenchymal stem cell fates, recent studies in cultured cells suggest that down-regulation of RhoA activity in specified myoblasts is required for subsequent differentiation and myotube formation. However, whether this phenomenon occurs in vivo and which Rho modifiers control these later events remain unclear. We found that expression of the Rho-GTPase-activating protein, GRAF1, was transiently up-regulated during myogenesis, and studies in C2C12 cells revealed that GRAF1 is necessary and sufficient for mediating RhoA down-regulation and inducing muscle differentiation. Moreover, forced expression of GRAF1 in pre-differentiated myoblasts drives robust muscle fusion by a process that requires GTPase-activating protein-dependent actin remodeling and BAR-dependent membrane binding or sculpting. Moreover, morpholino-based knockdown studies in Xenopus laevis determined that GRAF1 expression is critical for muscle development. GRAF1-depleted embryos exhibited elevated RhoA activity and defective myofibrillogenesis that resulted in progressive muscle degeneration, defective motility, and embryonic lethality. Our results are the first to identify a GTPase-activating protein that regulates muscle maturation and to highlight the functional importance of BAR domains in myotube formation.
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29
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van Weerd JH, Koshiba-Takeuchi K, Kwon C, Takeuchi JK. Epigenetic factors and cardiac development. Cardiovasc Res 2011; 91:203-11. [PMID: 21606181 DOI: 10.1093/cvr/cvr138] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Congenital heart malformations remain the leading cause of death related to birth defects. Recent advances in developmental and regenerative cardiology have shed light on a mechanistic understanding of heart development that is controlled by a transcriptional network of genetic and epigenetic factors. This article reviews the roles of chromatin remodelling factors important for cardiac development with the current knowledge of cardiac morphogenesis, regeneration, and direct cardiac differentiation. In the last 5 years, critical roles of epigenetic factors have been revealed in the cardiac research field.
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Affiliation(s)
- Jan Hendrick van Weerd
- Cardiovascular Regeneration, Institute of Molecular and Cellular Biosciences, University of Tokyo, Tokyo, Japan
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30
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Liao XH, Wang N, Liu QX, Qin T, Cao B, Cao DS, Zhang TC. Myocardin-related transcription factor-A induces cardiomyocyte hypertrophy. IUBMB Life 2011; 63:54-61. [PMID: 21280178 DOI: 10.1002/iub.415] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Myocardin is a remarkably potent transcriptional coactivator expressed specifically in cardiac muscle lineages and smooth muscle cells during postnatal development. Myocardin shares homology with myocardin-related transcription factor-A (MRTF-A), which are expressed in a broad range of embryonic and adult tissues. Our previous results show that myocardin induces cardiac hypertrophy. However, the effects of MRTF-A in cardiac hypertrophy remain poorly understood. Our present work further demonstrates that myocardin plays an important role in inducing hypertrophy. At the same time, we find that overexpression of MRTF-A in neonatal rat cardiomyocytes might induce cardiomyocyte hypertrophy. Furthermore, MRTF-A expression is induced in phenylephrine, angiotensin-II, and transforming growth factor-β-stimulated cardiac hypertrophy, whereas a dominant-negative form of MRTF-A or MRTF-A siRNA strongly inhibited upregulation of hypertrophy genes in response to hypertrophic agonists in neonatal rat cardiomyocytes. Our studies indicate that besides myocardin, MRTF-A might play an important role in cardiac hypertrophy. Our findings provide novel evidence for the future studies to explore the roles of MRTFs in cardiac hypertrophy.
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Affiliation(s)
- Xing-Hua Liao
- Key Laboratory of Industrial Microbiology, Ministry of Education and Tianjin, Tianjin, China
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31
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Afouda BA, Hoppler S. Different requirements for GATA factors in cardiogenesis are mediated by non-canonical Wnt signaling. Dev Dyn 2011; 240:649-62. [DOI: 10.1002/dvdy.22570] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/30/2010] [Indexed: 01/21/2023] Open
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32
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Abstract
Abstract The establishment of efficient methods for promoting stem cell differentiation into target cells is important not only in regenerative medicine, but also in drug discovery. In addition to embryonic stem (ES) cells and various somatic stem cells, such as mesenchymal stem cells derived from bone marrow, adipose tissue, and umbilical cord blood, a novel dedifferentiation technology that allows the generation of induced pluripotent stem (iPS) cells has been recently developed. Although an increasing number of stem cell populations are being described, there remains a lack of protocols for driving the differentiation of these cells. Regeneration of organs from stem cells in vitro requires precise blueprints for each differentiation step. To date, studies using various model organisms, such as zebrafish, Xenopus laevis, and gene-targeted mice, have uncovered several factors that are critical for the development of organs. We have been using X. laevis, the African clawed frog, which has developmental patterns similar to those seen in humans. Moreover, Xenopus embryos are excellent research tools for the development of differentiation protocols, since they are available in high numbers and are sufficiently large and robust for culturing after simple microsurgery. In addition, Xenopus eggs are fertilized externally, and all stages of the embryo are easily accessible, making it relatively easy to study the functions of individual gene products during organogenesis using microinjection into embryonic cells. In the present review, we provide examples of methods for in vitro organ formation that use undifferentiated Xenopus cells. We also describe the application of amphibian differentiation protocols to mammalian stem cells, so as to facilitate the development of efficient methodologies for in vitro differentiation.
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Affiliation(s)
- Akira Kurisaki
- Organ Development Research Laboratory, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan
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33
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Doherty JT, Conlon FL, Mack CP, Taylor JM. Focal adhesion kinase is essential for cardiac looping and multichamber heart formation. Genesis 2010; 48:492-504. [PMID: 20572259 PMCID: PMC3618911 DOI: 10.1002/dvg.20650] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Focal adhesion kinase (FAK) is a critical mediator of matrix- and growth factor-induced signaling during development. Myocyte-restricted FAK deletion in mid-gestation mice results in impaired ventricular septation and cardiac compaction. However, whether FAK regulates early cardiogenic steps remains unknown. To explore a role for FAK in multi-chambered heart formation, we utilized anti-sense morpholinos to deplete FAK in Xenopus laevis. Xenopus FAK morphants exhibited impaired cardiogenesis, pronounced pericardial edema, and lethality by tadpole stages. Spatial-temporal assessment of cardiac marker gene expression revealed that FAK was not necessary for midline migration, differentiation, fusion of cardiac precursors, or linear heart tube formation. However, myocyte proliferation was significantly reduced in FAK morphant heart tubes and these tubes failed to undergo proper looping morphogenesis. Collectively our data imply that FAK plays an essential role in chamber outgrowth and looping morphogenesis likely stimulated by fibroblast growth factors (and possibly other) cardiotrophic factors.
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MESH Headings
- Animals
- Blotting, Western
- Caspase 3/metabolism
- Cell Proliferation/drug effects
- Cells, Cultured
- Embryo, Nonmammalian/embryology
- Embryo, Nonmammalian/enzymology
- Embryo, Nonmammalian/metabolism
- Fibroblast Growth Factor 2/pharmacology
- Focal Adhesion Protein-Tyrosine Kinases/antagonists & inhibitors
- Focal Adhesion Protein-Tyrosine Kinases/genetics
- Focal Adhesion Protein-Tyrosine Kinases/metabolism
- Gene Expression Regulation, Developmental
- Gene Knockdown Techniques
- Heart/drug effects
- Heart/embryology
- Immunohistochemistry
- In Situ Hybridization
- Microinjections
- Microscopy, Confocal
- Morphogenesis/genetics
- Myocardium/enzymology
- Myocardium/metabolism
- Myocytes, Cardiac/cytology
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Oligonucleotides, Antisense/administration & dosage
- Oligonucleotides, Antisense/genetics
- Pyrroles/pharmacology
- Reverse Transcriptase Polymerase Chain Reaction
- Tropomyosin/metabolism
- Xenopus laevis/embryology
- Xenopus laevis/genetics
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Affiliation(s)
- Jason T. Doherty
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Frank L. Conlon
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Christopher P. Mack
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Joan M. Taylor
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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34
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Small EM, Thatcher JE, Sutherland LB, Kinoshita H, Gerard RD, Richardson JA, DiMaio JM, Sadek H, Kuwahara K, Olson EN. Myocardin-related transcription factor-a controls myofibroblast activation and fibrosis in response to myocardial infarction. Circ Res 2010; 107:294-304. [PMID: 20558820 PMCID: PMC2921870 DOI: 10.1161/circresaha.110.223172] [Citation(s) in RCA: 307] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
RATIONALE Myocardial infarction (MI) results in loss of cardiac myocytes in the ischemic zone of the heart, followed by fibrosis and scar formation, which diminish cardiac contractility and impede angiogenesis and repair. Myofibroblasts, a specialized cell type that switches from a fibroblast-like state to a contractile, smooth muscle-like state, are believed to be primarily responsible for fibrosis of the injured heart and other tissues, although the transcriptional mediators of fibrosis and myofibroblast activation remain poorly defined. Myocardin-related transcription factors (MRTFs) are serum response factor (SRF) cofactors that promote a smooth muscle phenotype and are emerging as components of stress-responsive signaling. OBJECTIVE We aimed to examine the effect of MRTF-A on cardiac remodeling and fibrosis. METHODS AND RESULTS Here, we show that MRTF-A controls the expression of a fibrotic gene program that includes genes involved in extracellular matrix production and smooth muscle cell differentiation in the heart. In MRTF-A-null mice, fibrosis and scar formation following MI or angiotensin II treatment are dramatically diminished compared with wild-type littermates. This protective effect of MRTF-A deletion is associated with a reduction in expression of fibrosis-associated genes, including collagen 1a2, a direct transcriptional target of SRF/MRTF-A. CONCLUSIONS We conclude that MRTF-A regulates myofibroblast activation and fibrosis in response to the renin-angiotensin system and post-MI remodeling.
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Affiliation(s)
- Eric M. Small
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jeffrey E. Thatcher
- Department of Cardiovascular and Thoracic Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Lillian B. Sutherland
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Hideyuki Kinoshita
- Department of Medicine and Clinical Science Kyoto Graduate School of Medicine, Kyoto, Japan
| | - Robert D. Gerard
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - James A. Richardson
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - J. Michael DiMaio
- Department of Cardiovascular and Thoracic Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Hesham Sadek
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Koichiro Kuwahara
- Department of Medicine and Clinical Science Kyoto Graduate School of Medicine, Kyoto, Japan
| | - Eric N. Olson
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Abstract
Sumoylation is a posttranslational modification process in which SUMO proteins are covalently and reversibly conjugated to their targets via enzymatic cascade reactions. Since the discovery of SUMO-1 in 1996, the SUMO pathway has garnered increased attention due to its role in a number of important biological activities such as cell cycle progression, epigenetic modulation, signal transduction, and DNA replication/repair, as well as its potential implication in human pathogenesis such as in cancer development and metastasis, neurodegenerative disorders and craniofacial defects. The role of the SUMO pathway in regulating cardiogenic gene activity, development and/or disorders is just emerging. Our review is based on recent advances that highlight the regulation of cardiac gene activity in cardiac development and disease by the SUMO conjugation pathway.
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Affiliation(s)
- Jun Wang
- Center for Stem Cell Engineering, Department of Basic Research Laboratories, Texas Heart Institute, Houston, TX 77030
| | - Robert J Schwartz
- Center for Stem Cell Engineering, Department of Basic Research Laboratories, Texas Heart Institute, Houston, TX 77030
- Department of Biology and Biochemistry, University of Houston, Houston, TX
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Martin J, Afouda BA, Hoppler S. Wnt/beta-catenin signalling regulates cardiomyogenesis via GATA transcription factors. J Anat 2010; 216:92-107. [PMID: 20402826 DOI: 10.1111/j.1469-7580.2009.01171.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
A functioning heart muscle is required continuously throughout life. During embryonic development the heart muscle tissue differentiates from mesoderm that has heart-forming potential. Heart-forming potential in the embryonic mesoderm is regulated by pro-cardiogenic transcription factors, such as members of the GATA and NK-2 transcription factor families. Subsequent heart muscle differentiation involves the expression of cytoskeletal proteins, including myosins and troponins. Different Wnt signalling pathways have various functions in heart development. So-called 'canonical' (Wnt/beta-catenin-mediated) signalling has a conserved role in vertebrate heart development, regulating and restricting heart development and subsequent heart muscle differentiation. Here we investigated the way in which Wnt/beta-catenin signalling functionally interacts with the GATA family of pro-cardiogenic transcription factors to regulate subsequent heart muscle differentiation. We used whole Xenopus embryos as an accessible experimental model system for vertebrate heart development. Our experiments confirmed that activation of Wnt signalling results in reduced gata gene expression, as well as reduced gene expression of other pro-cardiogenic transcription factors and heart muscle differentiation markers. Remarkably, we discovered that when GATA function is experimentally restored, the expression of other pro-cardiogenic transcription factors and heart muscle differentiation markers is rescued. These findings, obtained from whole-embryo experiments, show that Wnt signalling regulates heart development at the level of GATA factors, confirming earlier results from tissue-culture experiments. Furthermore, our rescue experiments in Xenopus embryos revealed differences in functional activity between the various GATA transcription factors involved in heart development. We discovered that GATA4 is more efficient at reinstating the gene expression of other pro-cardiogenic transcription factors, whereas GATA6 is more potent at promoting the expression of genes associated with terminal heart muscle differentiation. In conclusion, our findings show that the inhibition of heart development by Wnt/beta-catenin signalling during organogenesis is mediated by the loss of expression of GATA pro-cardiogenic transcription factors and reveal functional differences between those GATA factors in heart development.
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Affiliation(s)
- Jennifer Martin
- Cell and Developmental Biology Research Programme, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, UK
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37
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Hoppler S, Afouda BA. Cardiac MHCα expression in Xenopus. Development 2010. [DOI: 10.1242/dev.046334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Stefan Hoppler
- Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Boni Anatole Afouda
- Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK
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Schuff M, Siegel D, Bardine N, Oswald F, Donow C, Knöchel W. FoxO genes are dispensable during gastrulation but required for late embryogenesis in Xenopus laevis. Dev Biol 2009; 337:259-73. [PMID: 19895805 DOI: 10.1016/j.ydbio.2009.10.036] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Revised: 10/27/2009] [Accepted: 10/27/2009] [Indexed: 12/31/2022]
Abstract
Forkhead box (Fox) transcription factors of subclass O are involved in cell survival, proliferation, apoptosis, cell metabolism and prevention of oxidative stress. FoxO genes are highly conserved throughout evolution and their functions were analyzed in several vertebrate and invertebrate organisms. We here report on the identification of FoxO4 and FoxO6 genes in Xenopus laevis and analyze their expression patterns in comparison with the previously described FoxO1 and FoxO3 genes. We demonstrate significant differences in their temporal and spatial expression during embryogenesis and in their relative expression within adult tissues. Overexpression of FoxO1, FoxO4 or FoxO6 results in severe gastrulation defects, while overexpression of FoxO3 reveals this defect only in a constitutively active form containing mutations of Akt-1 target sites. Injections of FoxO antisense morpholino oligonucleotides (MO) did not influence gastrulation, but, later onwards, the embryos showed a delay of development, severe body axis reduction and, finally, a high rate of lethality. Injection of FoxO4MO leads to specific defects in eye formation, neural crest migration and heart development, the latter being accompanied by loss of myocardin expression. Our observations suggest that FoxO genes in X. laevis are dispensable until blastopore closure but are required for tissue differentiation and organogenesis.
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Affiliation(s)
- Maximilian Schuff
- Institute of Biochemistry, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
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39
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Myocardin is required for cardiomyocyte survival and maintenance of heart function. Proc Natl Acad Sci U S A 2009; 106:18734-9. [PMID: 19850880 DOI: 10.1073/pnas.0910749106] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Despite intense investigation over the past century, the molecular mechanisms that regulate maintenance and adaptation of the heart during postnatal development are poorly understood. Myocardin is a remarkably potent transcriptional coactivator expressed exclusively in cardiac myocytes and smooth muscle cells during postnatal development. Here we show that myocardin is required for maintenance of cardiomyocyte structure and sarcomeric organization and that cell-autonomous loss of myocardin in cardiac myocytes triggers programmed cell death. Mice harboring a cardiomyocyte-restricted null mutation in the myocardin gene (Myocd) develop dilated cardiomyopathy and succumb from heart failure within a year. Remarkably, ablation of the Myocd gene in the adult heart leads to the rapid-onset of heart failure, dilated cardiomyopathy, and death within a week. Myocd gene ablation is accompanied by dissolution of sarcomeric organization, disruption of the intercalated disc, and cell-autonomous loss of cardiomyocytes via apoptosis. Expression of myocardin/serum response factor-regulated myofibrillar genes is extinguished, or profoundly attenuated, in myocardin-deficient hearts. Conversely, proapoptotic factors are induced and activated in myocardin-deficient hearts. We conclude that the transcriptional coactivator myocardin is required for maintenance of heart function and ultimately cardiomyocyte survival.
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40
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Abu-Daya A, Sater AK, Wells DE, Mohun TJ, Zimmerman LB. Absence of heartbeat in the Xenopus tropicalis mutation muzak is caused by a nonsense mutation in cardiac myosin myh6. Dev Biol 2009; 336:20-9. [PMID: 19769958 PMCID: PMC2786259 DOI: 10.1016/j.ydbio.2009.09.019] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Revised: 08/17/2009] [Accepted: 09/14/2009] [Indexed: 11/25/2022]
Abstract
Mechanisms coupling heart function and cardiac morphogenesis can be
accessed in lower vertebrate embryos that can survive to swimming tadpole stages
on diffused oxygen. Forward genetic screens in Xenopus
tropicalis have identified more than 80 mutations affecting diverse
developmental processes, including cardiac morphogenesis and function. In the
first positional cloning of a mutation in X. tropicalis, we
show that non-contractile hearts in muzak (muz) embryos are
caused by a premature stop codon in the cardiac myosin heavy chain gene
myh6. The mutation deletes the coiled-coil domain
responsible for polymerization into thick filaments, severely disrupting the
cardiomyocyte cytoskeleton. Despite the lack of contractile activity and absence
of a major structural protein, early stages of cardiac morphogenesis including
looping and chamber formation are grossly normal. Muz hearts
subsequently develop dilated chambers with compressed endocardium and fail to
form identifiable cardiac valves and trabeculae.
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Affiliation(s)
- Anita Abu-Daya
- MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, NW7 1AA, UK
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41
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Keren-Politansky A, Keren A, Bengal E. Neural ectoderm-secreted FGF initiates the expression of Nkx2.5 in cardiac progenitors via a p38 MAPK/CREB pathway. Dev Biol 2009; 335:374-84. [PMID: 19765572 DOI: 10.1016/j.ydbio.2009.09.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Revised: 09/09/2009] [Accepted: 09/10/2009] [Indexed: 11/26/2022]
Abstract
Vertebrate heart development is derived from paired primordia of anterior dorsolateral mesoderm expressing Nkx2.5 and GATA4 transcription factors. Yet growth factors and intracellular pathways specifying heart precursor gene expression are poorly understood. In the present work, we investigated the signaling events initiating Nkx2.5 expression in Xenopus laevis. We describe here that fibroblast growth factor (FGF) initiates the expression of Nkx2.5 without affecting GATA4. At gastrula, FGF3 is expressed in anterior neural ectoderm, and results presented here indicate that this tissue is involved in the induction of Nkx2.5 expression in neighboring lateral tissues. Further studies indicate that the intracellular p38 MAPK and the CREB transcription factor function downstream of FGF to initiate Nkx2.5 expression. Activation of the p38 MAPK pathway and of the CREB protein is both necessary and sufficient for the initial expression of Nkx2.5. Therefore, we would like to suggest that FGF expressed in anterior neural ectoderm is a major inducer of Nkx2.5 expression in neighboring cells. In these cells, FGF activates an intracellular p38 MAPK signaling pathway and its downstream target, the CREB transcription factor, all participating in the expression of Nkx2.5 in cardiac progenitors.
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Affiliation(s)
- Anat Keren-Politansky
- Department of Biochemistry, Rappaport Institute for Research in the Medical Sciences, Haifa, Israel
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42
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Miazga CM, McLaughlin KA. Coordinating the timing of cardiac precursor development during gastrulation: A new role for Notch signaling. Dev Biol 2009; 333:285-96. [DOI: 10.1016/j.ydbio.2009.06.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Revised: 06/16/2009] [Accepted: 06/27/2009] [Indexed: 10/20/2022]
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43
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Takeuchi JK, Bruneau BG. Directed transdifferentiation of mouse mesoderm to heart tissue by defined factors. Nature 2009; 459:708-11. [PMID: 19396158 PMCID: PMC2728356 DOI: 10.1038/nature08039] [Citation(s) in RCA: 398] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Accepted: 04/07/2009] [Indexed: 12/11/2022]
Abstract
Heart disease is the leading cause of mortality and morbidity in the western world. The heart has little regenerative capacity after damage, leading to much interest in understanding the factors required to produce new cardiac myocytes. Despite a robust understanding of the molecular networks regulating cardiac differentiation, no single transcription factor or combination of factors has been shown to activate the cardiac gene program de novo in mammalian cells or tissues. Here we define the minimal requirements for transdifferentiation of mouse mesoderm to cardiac myocytes. We show that two cardiac transcription factors, Gata4 and Tbx5, and a cardiac-specific subunit of BAF chromatin-remodelling complexes, Baf60c (also called Smarcd3), can direct ectopic differentiation of mouse mesoderm into beating cardiomyocytes, including the normally non-cardiogenic posterior mesoderm and the extraembryonic mesoderm of the amnion. Gata4 with Baf60c initiated ectopic cardiac gene expression. Addition of Tbx5 allowed differentiation into contracting cardiomyocytes and repression of non-cardiac mesodermal genes. Baf60c was essential for the ectopic cardiogenic activity of Gata4 and Tbx5, partly by permitting binding of Gata4 to cardiac genes, indicating a novel instructive role for BAF complexes in tissue-specific regulation. The combined function of these factors establishes a robust mechanism for controlling cellular differentiation, and may allow reprogramming of new cardiomyocytes for regenerative purposes.
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Affiliation(s)
- Jun K Takeuchi
- Gladstone Institute of Cardiovascular Disease, San Francisco, California 94158, USA.
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44
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Asashima M, Ito Y, Chan T, Michiue T, Nakanishi M, Suzuki K, Hitachi K, Okabayashi K, Kondow A, Ariizumi T. In vitro organogenesis from undifferentiated cells inXenopus. Dev Dyn 2009; 238:1309-20. [DOI: 10.1002/dvdy.21979] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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45
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Xu Z, Chan HY, Lam WL, Lam KH, Lam LSM, Ng TB, Au SWN. SUMO proteases: redox regulation and biological consequences. Antioxid Redox Signal 2009; 11:1453-84. [PMID: 19186998 DOI: 10.1089/ars.2008.2182] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Small-ubiquitin modifier (SUMO) has emerged as a novel modification system that governs the activities of a wide spectrum of protein substrates. SUMO-specific proteases (SENP) are of particular interest, as they are responsible for both the maturation of SUMO precursors and for their deconjugation. The interruption of SENPs has been implicated in embryonic defects and carcinoma cells, indicating that a proper balance of SUMO conjugation and deconjugation is crucial. Recent advances in molecular and cellular biology have highlighted the distinct subcellular localization, and endopeptidase and isopeptidase activities of SENPs, suggesting that they are nonredundant. A better understanding of the molecular basis of SUMO recognition and hydrolytic cleavage has been obtained from the crystal structures of SENP-substrate complexes. While a number of proteomic studies have shown an upregulation of sumoylation, attention is now increasingly being directed towards the regulatory mechanism of sumoylation, in particular the oxidative effect. Findings on the oxidation-induced intermolecular disulfide of E1-E2 ligases and SENP1/2 have improved our understanding of the mechanism by which modification is switched up or down. More intriguingly, a growing body of evidence suggests that sumoylation cross-talks with other modifications, and that the upstream and downstream signaling pathway is co-regulated by more than one modifier.
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Affiliation(s)
- Zheng Xu
- Centre for Protein Science and Crystallography, Department of Biochemistry and Molecular Biotechnology Program, Faculty of Science, The Chinese University of Hong Kong, Hong Kong
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46
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Barillot W, Tréguer K, Faucheux C, Fédou S, Thézé N, Thiébaud P. Induction and modulation of smooth muscle differentiation in Xenopus embryonic cells. Dev Dyn 2009; 237:3373-86. [PMID: 18855898 DOI: 10.1002/dvdy.21749] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
By comparison with skeletal or cardiac developmental programs, little is known regarding the specific factors that promote specification and differentiation of smooth muscle cells from pluripotent cells. We have analyzed the developmental expression of a subset of smooth muscle genes during Xenopus early development and showed that similar to mammals and avians, Xenopus smooth muscle myosin heavy chain (SM-MHC) is a highly specific marker of smooth muscle differentiation. Embryonic cells from animal pole explants of Xenopus blastula can be induced by basic fibroblast growth factor, Wnt, and bone morphogenetic protein signals to adopt the smooth muscle pathway. Explants from early embryos that contain neural crest cells can also differentiate into cells expressing smooth muscle genes. We examined the interplay of several transcription factors, that is SRF, myocardin, and GATA6, that induce the expression of SM-MHC in animal cap cells and found that myocardin-dependent expression of smooth muscle genes in animal cap cells is synergized by SRF but is strongly antagonized by GATA6.
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47
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Wong A, Woodcock EA. FoxO proteins and cardiac pathology. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 665:78-89. [PMID: 20429417 DOI: 10.1007/978-1-4419-1599-3_6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The FoxO family of transcription factors mediate a wide range of cellular responses from cell death to cell survival, growth inhibition and glucose utilization. This complex array of responses is regulated by an equally complex regulatory system, involving phosphorylation, ubiquitinization and acetylation, in addition to interactions with other transcription factors and transcriptional modifiers. In heart, FoxO proteins have been shown to be involved in development in limiting hypertrophic growth responses and in cardioprotection provided by silent information regulator 1 (Sirt1). However, the range of responses mediated by FoxO proteins and the clear evidence for involvement of FoxO regulators in cardiac pathology, suggest that further pathological actions of FoxO family members remain to be elucidated.
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Affiliation(s)
- Albert Wong
- Molecular Cardiology Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
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48
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Lavery DL, Martin J, Turnbull YD, Hoppler S. Wnt6 signaling regulates heart muscle development during organogenesis. Dev Biol 2008; 323:177-88. [PMID: 18804460 PMCID: PMC2593796 DOI: 10.1016/j.ydbio.2008.08.032] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Revised: 08/15/2008] [Accepted: 08/20/2008] [Indexed: 11/07/2022]
Abstract
Mesodermal tissue with heart forming potential (cardiogenic mesoderm) is induced during gastrulation. This cardiogenic mesoderm later differentiates into heart muscle tissue (myocardium) and non-muscular heart tissue. Inhibition of Wnt/beta-catenin signaling is known to be required early for induction of cardiogenic mesoderm; however, the identity of the inhibiting Wnt signal itself is still elusive. We have identified Wnt6 in Xenopus as an endogenous Wnt signal, which is expressed in tissues close to and later inside the developing heart. Our loss-of-function experiments show that Wnt6 function is required in the embryo to prevent development of an abnormally large heart muscle. We find, however, that Wnt6 is not required as expected during gastrulation stages, but later during organogenesis stages just before cells of the cardiogenic mesoderm begin to differentiate into heart muscle (myocardium). Our gain-of-function experiments show that Wnt6 and also activated canonical Wnt/beta-catenin signaling are capable of restricting heart muscle development at these relatively late stages of development. This repressive role of Wnt signaling is mediated initially via repression of cardiogenic transcription factors, since reinstatement of GATA function can rescue expression of other cardiogenic transcription factors and downstream cardiomyogenic differentiation genes.
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Affiliation(s)
| | | | | | - Stefan Hoppler
- Institute of Medical Sciences, Cell and Developmental Biology Research Programme, University of Aberdeen, Foresterhill, ABERDEEN, AB25 2ZD, Scotland, UK
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49
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CHEN JIANFU, WANG SHUSHENG, WU QIULIAN, CAO DONGSUN, NGUYEN THIHA, CHEN YIPING, WANG DAZHI. Myocardin marks the earliest cardiac gene expression and plays an important role in heart development. Anat Rec (Hoboken) 2008; 291:1200-11. [PMID: 18780304 PMCID: PMC2694184 DOI: 10.1002/ar.20756] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Myocardin belongs to the SAP domain family of transcription factors and is expressed specifically in cardiac and smooth muscle during embryogenesis and in adulthood. Myocardin functions as a transcriptional coactivator of SRF and is sufficient and necessary for smooth muscle gene expression. However, the in vivo function of myocardin during cardiogenesis is not completely understood. Here we clone myocardin from chick embryonic hearts and show that myocardin protein sequences are highly conserved cross species. Detailed studies of chick myocardin expression reveal that myocardin is expressed in cardiac and smooth muscle lineage during early embryogenesis, similar to that found in mouse. Interestingly, the expression of myocardin in the heart was found enriched in the outflow tract and the sinoatrial segments shortly after the formation of linear heart tube. Such expression pattern is also maintained in later developing embryos, suggesting that myocardin may play a unique role in the formation of those cardiac modules. Similar to its mouse counterpart, chick myocardin is able to activate cardiac and smooth muscle promoter reporter genes and induce smooth muscle gene expression in nonmuscle cells. Ectopic overexpression of myocardin enlarged the embryonic chick heart. Conversely, repression of the endogenous chick myocardin using antisense oligonucleotides or a dominant negative mutant form of myocardin inhibited cardiogenesis. Together, our data place myocardin as one of the earliest cardiac marker genes for cardiogenesis and support the idea that myocardin plays an essential role in cardiac gene expression and cardiogenesis.
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Affiliation(s)
- JIAN-FU CHEN
- Carolina Cardiovascular Biology Center, Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, North Carolina
| | - SHUSHENG WANG
- Department of Cell and Molecular Biology, Tulane University, New Orleans, Louisiana
| | - QIULIAN WU
- Carolina Cardiovascular Biology Center, Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, North Carolina
| | - DONGSUN CAO
- Carolina Cardiovascular Biology Center, Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, North Carolina
| | - THIHA NGUYEN
- Carolina Cardiovascular Biology Center, Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, North Carolina
| | - YIPING CHEN
- Department of Cell and Molecular Biology, Tulane University, New Orleans, Louisiana
| | - DA-ZHI WANG
- Carolina Cardiovascular Biology Center, Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, North Carolina
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50
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Long X, Bell RD, Gerthoffer WT, Zlokovic BV, Miano JM. Myocardin is sufficient for a smooth muscle-like contractile phenotype. Arterioscler Thromb Vasc Biol 2008; 28:1505-10. [PMID: 18451334 PMCID: PMC2574857 DOI: 10.1161/atvbaha.108.166066] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Myocardin (Myocd) is a strong coactivator that binds the serum response factor (SRF) transcription factor over CArG elements embedded within smooth muscle cell (SMC) and cardiac muscle cyto-contractile genes. Here, we sought to ascertain whether Myocd-mediated gene expression confers a structural and physiological cardiac or SMC phenotype. METHODS AND RESULTS Adenoviral-mediated expression of Myocd in the BC(3)H1 cell line induces cardiac and SMC genes while suppressing both skeletal muscle markers and cell growth. Immunofluorescence microscopy shows that SRF and a SMC-like cyto-contractile apparatus are elevated with Myocd overexpression. A short hairpin RNA to Srf impairs BC(3)H1 cyto-architecture; however, cotransduction with Myocd results in complete restoration of the cyto-architecture. Electron microscopic studies demonstrate a SMC ultrastructural phenotype with no evidence for cardiac sarcomerogenesis. Biochemical and time-lapsed videomicroscopy assays reveal clear evidence for Myocd-induced SMC-like contraction. CONCLUSIONS Myocd is sufficient for the establishment of a SMC-like contractile phenotype.
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Affiliation(s)
- Xiaochun Long
- Aab Cardiovascular Research Institute, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
| | - Robert D. Bell
- Center for Neurodegenerative and Vascular Brain Disorders, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
| | | | - Berislav V. Zlokovic
- Center for Neurodegenerative and Vascular Brain Disorders, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
| | - Joseph M. Miano
- Aab Cardiovascular Research Institute, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
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