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Inazumi H, Kuwahara K. NRSF/REST-Mediated Epigenomic Regulation in the Heart: Transcriptional Control of Natriuretic Peptides and Beyond. BIOLOGY 2022; 11:1197. [PMID: 36009824 PMCID: PMC9405064 DOI: 10.3390/biology11081197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/07/2022] [Accepted: 08/09/2022] [Indexed: 11/17/2022]
Abstract
Reactivation of fetal cardiac genes, including those encoding atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), is a key feature of pathological cardiac remodeling and heart failure. Intensive studies on the regulation of ANP and BNP have revealed the involvement of numerous transcriptional factors in the regulation of the fetal cardiac gene program. Among these, we identified that a transcriptional repressor, neuron-restrictive silencer factor (NRSF), also named repressor element-1-silencing transcription factor (REST), which was initially detected as a transcriptional repressor of neuron-specific genes in non-neuronal cells, plays a pivotal role in the transcriptional regulation of ANP, BNP and other fetal cardiac genes. Here we review the transcriptional regulation of ANP and BNP gene expression and the role of the NRSF repressor complex in the regulation of cardiac gene expression and the maintenance of cardiac homeostasis.
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Affiliation(s)
- Hideaki Inazumi
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, 54 Shogoin-kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Koichiro Kuwahara
- Department of Cardiovascular Medicine, School of Medicine, Shinshu University, 3-1-1 Asahi, Nagano 390-8621, Japan
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2
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Forte E, Ramialison M, Nim HT, Mara M, Li JY, Cohn R, Daigle SL, Boyd S, Stanley EG, Elefanty AG, Hinson JT, Costa MW, Rosenthal NA, Furtado MB. Adult mouse fibroblasts retain organ-specific transcriptomic identity. eLife 2022; 11:71008. [PMID: 35293863 PMCID: PMC8959603 DOI: 10.7554/elife.71008] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 03/15/2022] [Indexed: 01/18/2023] Open
Abstract
Organ fibroblasts are essential components of homeostatic and diseased tissues. They participate in sculpting the extracellular matrix, sensing the microenvironment, and communicating with other resident cells. Recent studies have revealed transcriptomic heterogeneity among fibroblasts within and between organs. To dissect the basis of interorgan heterogeneity, we compare the gene expression of murine fibroblasts from different tissues (tail, skin, lung, liver, heart, kidney, and gonads) and show that they display distinct positional and organ-specific transcriptome signatures that reflect their embryonic origins. We demonstrate that expression of genes typically attributed to the surrounding parenchyma by fibroblasts is established in embryonic development and largely maintained in culture, bioengineered tissues and ectopic transplants. Targeted knockdown of key organ-specific transcription factors affects fibroblast functions, in particular genes involved in the modulation of fibrosis and inflammation. In conclusion, our data reveal that adult fibroblasts maintain an embryonic gene expression signature inherited from their organ of origin, thereby increasing our understanding of adult fibroblast heterogeneity. The knowledge of this tissue-specific gene signature may assist in targeting fibrotic diseases in a more precise, organ-specific manner.
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Affiliation(s)
| | - Mirana Ramialison
- Australian Regenerative Medicine Institute, Monash University, Clayton, Australia
| | - Hieu T Nim
- Faculty of Information Technology, Monash University, Clayton, Australia
| | | | - Jacky Y Li
- Murdoch Children's Research Institute, Parkville, Australia
| | - Rachel Cohn
- Jackson Laboratory, Farmington, United States
| | | | - Sarah Boyd
- Centre for Inflammatory Diseases, Monash University, Clayton, Australia
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Mengmeng X, Yuejuan X, Sun C, Yanan L, Fen L, Kun S. Novel mutations of the SRF gene in Chinese sporadic conotruncal heart defect patients. BMC MEDICAL GENETICS 2020; 21:95. [PMID: 32380971 PMCID: PMC7203814 DOI: 10.1186/s12881-020-01032-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Accepted: 04/22/2020] [Indexed: 01/28/2023]
Abstract
BACKGROUND Conotruncal heart defects (CTDs) are a group of congenital heart malformations that cause anomalies of cardiac outflow tracts. In the past few decades, many genes related to CTDs have been reported. Serum response factor (SRF) is a ubiquitous nuclear protein that acts as transcription factor, and SRF was found to be a critical factor in heart development and to be strongly expressed in the myocardium of the developing mouse and chicken hearts. The targeted inactivation of SRF during heart development leads to embryonic lethality and myocardial defects in mice. METHODS To illustrate the relationship between SRF and human heart defects, we screened SRF mutations in 527 CTD patients, a cross sectional study. DNA was extracted from peripheral leukocyte cells for target sequencing. The mutations of SRF were detected and validated by Sanger sequencing. The affection of the mutations on wild-type protein was analyzed by in silico softwares. Western blot and real time PCR were used to analyze the changes of the expression of the mutant mRNA and protein. In addition, we carried out dual luciferase reporter assay to explore the transcriptional activity of the mutant SRF. RESULTS Among the target sequencing results of 527 patients, two novel mutations (Mut1: c.821A > G p.G274D, the adenine(A) was mutated to guanine(G) at position 821 of the SRF gene coding sequences (CDS), lead to the Glycine(G) mutated to Asparticacid(D) at position 274 of the SRF protein amino acid sequences; Mut2: c.880G > T p.G294C, the guanine(G) was mutated to thymine (T) at position 880 of the SRF CDS, lead to the Glycine(G) mutated to Cysteine (C) at position 294 of the SRF protein amino acid sequences.) of SRF (NM_003131.4) were identified. Western blotting and real-time PCR showed that there were no obvious differences between the protein expression and mRNA transcription of mutants and wild-type SRF. A dual luciferase reporter assay showed that both SRF mutants (G274D and G294C) impaired SRF transcriptional activity at the SRF promoter and atrial natriuretic factor (ANF) promoter (p < 0.05), additionally, the mutants displayed reduced synergism with GATA4. CONCLUSION These results suggest that SRF-p.G274D and SRF-p.G294C may have potential pathogenic effects.
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Affiliation(s)
- Xu Mengmeng
- Department of Pediatric Cardiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, No.1665 Kongjiang road, Shanghai, 200092, China
| | - Xu Yuejuan
- Department of Pediatric Cardiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, No.1665 Kongjiang road, Shanghai, 200092, China.
| | - Chen Sun
- Department of Pediatric Cardiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, No.1665 Kongjiang road, Shanghai, 200092, China
| | - Lu Yanan
- Department of Pediatric Cardiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, No.1665 Kongjiang road, Shanghai, 200092, China
| | - Li Fen
- Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, No. 1678, Dongfang Road, Shanghai, 200127, China
| | - Sun Kun
- Department of Pediatric Cardiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, No.1665 Kongjiang road, Shanghai, 200092, China.
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Jia Z, Jia J, Zhang S, Cao J. CMV enhancer may not be suitable for tissue-specific enhancement of promoters in cancer gene therapy. Cancer Gene Ther 2019; 27:389-392. [PMID: 31130730 DOI: 10.1038/s41417-019-0106-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 05/04/2019] [Indexed: 01/08/2023]
Affiliation(s)
- Zhenyu Jia
- Institute of Occupational Diseases, Zhejiang Academy of Medical Sciences, Hangzhou, China
| | - Jing Jia
- Center for Molecular Medicine, Zhejiang Academy of Medical Sciences, Hangzhou, China
| | - Shuzhi Zhang
- Institute of Occupational Diseases, Zhejiang Academy of Medical Sciences, Hangzhou, China
| | - Jiang Cao
- Clinical Research Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
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Kinnunen S, Välimäki M, Tölli M, Wohlfahrt G, Darwich R, Komati H, Nemer M, Ruskoaho H. Nuclear Receptor-Like Structure and Interaction of Congenital Heart Disease-Associated Factors GATA4 and NKX2-5. PLoS One 2015; 10:e0144145. [PMID: 26642209 PMCID: PMC4671672 DOI: 10.1371/journal.pone.0144145] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 11/13/2015] [Indexed: 01/24/2023] Open
Abstract
AIMS Transcription factor GATA4 is a dosage sensitive regulator of heart development and alterations in its level or activity lead to congenital heart disease (CHD). GATA4 has also been implicated in cardiac regeneration and repair. GATA4 action involves combinatorial interaction with other cofactors such as NKX2-5, another critical cardiac regulator whose mutations also cause CHD. Despite its critical importance to the heart and its evolutionary conservation across species, the structural basis of the GATA4-NKX2-5 interaction remains incompletely understood. METHODS AND RESULTS A homology model was constructed and used to identify surface amino acids important for the interaction of GATA4 and NKX2-5. These residues were subjected to site-directed mutagenesis, and the mutant proteins were characterized for their ability to bind DNA and to physically and functionally interact with NKX2-5. The studies identify 5 highly conserved amino acids in the second zinc finger (N272, R283, Q274, K299) and its C-terminal extension (R319) that are critical for physical and functional interaction with the third alpha helix of NKX2-5 homeodomain. Integration of the experimental data with computational modeling suggests that the structural arrangement of the zinc finger-homeodomain resembles the architecture of the conserved DNA binding domain of nuclear receptors. CONCLUSIONS The results provide novel insight into the structural basis for protein-protein interactions between two important classes of transcription factors. The model proposed will help to elucidate the molecular basis for disease causing mutations in GATA4 and NKX2-5 and may be relevant to other members of the GATA and NK classes of transcription factors.
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Affiliation(s)
- Sini Kinnunen
- Division of Pharmacology and Pharmacotherapy, University of Helsinki, Helsinki, Finland
- Institute of Biomedicine, Department of Pharmacology and Toxicology, University of Oulu, Oulu, Finland
| | - Mika Välimäki
- Division of Pharmacology and Pharmacotherapy, University of Helsinki, Helsinki, Finland
- Institute of Biomedicine, Department of Pharmacology and Toxicology, University of Oulu, Oulu, Finland
| | - Marja Tölli
- Institute of Biomedicine, Department of Pharmacology and Toxicology, University of Oulu, Oulu, Finland
| | - Gerd Wohlfahrt
- Orion Pharma, Computer-Aided Drug Design, Espoo, Finland
| | - Rami Darwich
- Laboratory of Cardiac Development and Differentiation, Department of Biochemistry, Immunology and Microbiology, University of Ottawa, Ottawa, Canada
| | - Hiba Komati
- Laboratory of Cardiac Development and Differentiation, Department of Biochemistry, Immunology and Microbiology, University of Ottawa, Ottawa, Canada
| | - Mona Nemer
- Laboratory of Cardiac Development and Differentiation, Department of Biochemistry, Immunology and Microbiology, University of Ottawa, Ottawa, Canada
- * E-mail: (HR); (MN)
| | - Heikki Ruskoaho
- Division of Pharmacology and Pharmacotherapy, University of Helsinki, Helsinki, Finland
- Institute of Biomedicine, Department of Pharmacology and Toxicology, University of Oulu, Oulu, Finland
- * E-mail: (HR); (MN)
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Abstract
The microRNAs and microRNA clusters have been implicated in normal cardiac development and also disease, including cardiac hypertrophy, cardiomyopathy, heart failure, and arrhythmias. Since a microRNA cluster has from two to dozens of microRNAs, the expression of a microRNA cluster could have a substantial impact on its target genes. In the present study, the configuration and distribution of microRNA clusters in the mouse genome were examined at various inter-microRNA distances. Three important microRNA clusters that are significantly impacted during adult cardiac aging, the miR-17-92, miR-106a-363, and miR-106b-25, were also examined in terms of their genomic location, RNA transcript character, sequence homology, and their relationship with the corresponding microRNA families. Multiple microRNAs derived from the three clusters potentially target various protein components of the cdc42-SRF signaling pathway, which regulates cytoskeleton dynamics associated with cardiac structure and function. The data indicate that aging impacted the expression of both guide and passenger strands of the microRNA clusters; nutrient stress also affected the expression of the three microRNA clusters. The miR-17-92, miR-106a-363, and miR-106b-25 clusters are likely to impact the Cdc42-SRF signaling pathway and thereby affect cardiac morphology and function during pathological conditions and the aging process.
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Huynen L, Suzuki T, Ogura T, Watanabe Y, Millar CD, Hofreiter M, Smith C, Mirmoeini S, Lambert DM. Reconstruction and in vivo analysis of the extinct tbx5 gene from ancient wingless moa (Aves: Dinornithiformes). BMC Evol Biol 2014; 14:75. [PMID: 24885927 PMCID: PMC4101845 DOI: 10.1186/1471-2148-14-75] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Accepted: 03/25/2014] [Indexed: 12/16/2022] Open
Abstract
Background The forelimb-specific gene tbx5 is highly conserved and essential for the development of forelimbs in zebrafish, mice, and humans. Amongst birds, a single order, Dinornithiformes, comprising the extinct wingless moa of New Zealand, are unique in having no skeletal evidence of forelimb-like structures. Results To determine the sequence of tbx5 in moa, we used a range of PCR-based techniques on ancient DNA to retrieve all nine tbx5 exons and splice sites from the giant moa, Dinornis. Moa Tbx5 is identical to chicken Tbx5 in being able to activate the downstream promotors of fgf10 and ANF. In addition we show that missexpression of moa tbx5 in the hindlimb of chicken embryos results in the formation of forelimb features, suggesting that Tbx5 was fully functional in wingless moa. An alternatively spliced exon 1 for tbx5 that is expressed specifically in the forelimb region was shown to be almost identical between moa and ostrich, suggesting that, as well as being fully functional, tbx5 is likely to have been expressed normally in moa since divergence from their flighted ancestors, approximately 60 mya. Conclusions The results suggests that, as in mice, moa tbx5 is necessary for the induction of forelimbs, but is not sufficient for their outgrowth. Moa Tbx5 may have played an important role in the development of moa’s remnant forelimb girdle, and may be required for the formation of this structure. Our results further show that genetic changes affecting genes other than tbx5 must be responsible for the complete loss of forelimbs in moa.
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Affiliation(s)
| | | | | | | | | | | | | | | | - David M Lambert
- Environmental Futures Centre, Griffith University, 170 Kessels Road, Nathan Qld 4111, Australia.
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UTX and UTY demonstrate histone demethylase-independent function in mouse embryonic development. PLoS Genet 2012; 8:e1002964. [PMID: 23028370 PMCID: PMC3459986 DOI: 10.1371/journal.pgen.1002964] [Citation(s) in RCA: 232] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2012] [Accepted: 08/08/2012] [Indexed: 11/19/2022] Open
Abstract
UTX (KDM6A) and UTY are homologous X and Y chromosome members of the Histone H3 Lysine 27 (H3K27) demethylase gene family. UTX can demethylate H3K27; however, in vitro assays suggest that human UTY has lost enzymatic activity due to sequence divergence. We produced mouse mutations in both Utx and Uty. Homozygous Utx mutant female embryos are mid-gestational lethal with defects in neural tube, yolk sac, and cardiac development. We demonstrate that mouse UTY is devoid of in vivo demethylase activity, so hemizygous XUtx− Y+ mutant male embryos should phenocopy homozygous XUtx− XUtx− females. However, XUtx− Y+ mutant male embryos develop to term; although runted, approximately 25% survive postnatally reaching adulthood. Hemizygous X+ YUty− mutant males are viable. In contrast, compound hemizygous XUtx− YUty− males phenocopy homozygous XUtx− XUtx− females. Therefore, despite divergence of UTX and UTY in catalyzing H3K27 demethylation, they maintain functional redundancy during embryonic development. Our data suggest that UTX and UTY are able to regulate gene activity through demethylase independent mechanisms. We conclude that UTX H3K27 demethylation is non-essential for embryonic viability. Trimethylation at Lysine 27 of histone H3 (H3K27me3) establishes a repressive chromatin state in silencing an array of crucial developmental genes. Polycomb repressive complex 2 (PRC2) catalyzes this precise posttranslational modification and is required in several critical aspects of development including Hox gene repression, gastrulation, X-chromosome inactivation, mono-allelic gene expression and imprinting, stem cell maintenance, and oncogenesis. Removal of H3K27 trimethylation has been proposed to be a mechanistic switch to activate large sets of genes in differentiating cells. Mouse Utx is an X-linked H3K27 demethylase that is essential for embryonic development. We now demonstrate that Uty, the Y-chromosome homolog of Utx, has overlapping redundancy with Utx in embryonic development. Mouse UTY has a polymorphism in the JmjC demethylase domain that renders the protein incapable of H3K27 demethylation. Therefore, the overlapping function of UTX and UTY in embryonic development is due to H3K27 demethylase independent mechanism. Moreover, the presence of UTY allows UTX-deficient mouse embryos to survive until birth. Thus, UTX H3K27 demethylation is not essential for embryonic viability. These intriguing results raise new questions on how H3K27me3 repression is removed in the early embryo.
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9
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Lavallée G, Andelfinger G, Nadeau M, Lefebvre C, Nemer G, Horb ME, Nemer M. The Kruppel-like transcription factor KLF13 is a novel regulator of heart development. EMBO J 2006; 25:5201-13. [PMID: 17053787 PMCID: PMC1630408 DOI: 10.1038/sj.emboj.7601379] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2006] [Accepted: 09/06/2006] [Indexed: 11/09/2022] Open
Abstract
In humans, congenital heart defects occur in 1-2% of live birth, but the molecular mechanisms and causative genes remain unidentified in the majority of cases. We have uncovered a novel transcription pathway important for heart morphogenesis. We report that KLF13, a member of the Krüppel-like family of zinc-finger proteins, is expressed predominantly in the heart, binds evolutionarily conserved regulatory elements on cardiac promoters and activates cardiac transcription. KLF13 is conserved across species and knockdown of KLF13 in Xenopus embryos leads to atrial septal defects and hypotrabeculation similar to those observed in humans or mice with hypomorphic GATA-4 alleles. Physical and functional interaction with GATA-4, a dosage-sensitive cardiac regulator, provides a mechanistic explanation for KLF13 action in the heart. The data demonstrate that KLF13 is an important component of the transcription network required for heart development and suggest that KLF13 is a GATA-4 modifier; by analogy to other GATA-4 collaborators, mutations in KLF13 may be causative for congenital human heart disease.
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Affiliation(s)
- Geneviève Lavallée
- Institut de recherches cliniques de Montréal (IRCM), Montréal, Quebec, Canada
- Université de Montréal, Montréal, Quebec, Canada
| | - Gregor Andelfinger
- Institut de recherches cliniques de Montréal (IRCM), Montréal, Quebec, Canada
- Université de Montréal, Montréal, Quebec, Canada
| | - Mathieu Nadeau
- Institut de recherches cliniques de Montréal (IRCM), Montréal, Quebec, Canada
- Université de Montréal, Montréal, Quebec, Canada
| | - Chantal Lefebvre
- Institut de recherches cliniques de Montréal (IRCM), Montréal, Quebec, Canada
- Université de Montréal, Montréal, Quebec, Canada
| | - Georges Nemer
- Institut de recherches cliniques de Montréal (IRCM), Montréal, Quebec, Canada
- Université de Montréal, Montréal, Quebec, Canada
| | - Marko E Horb
- Institut de recherches cliniques de Montréal (IRCM), Montréal, Quebec, Canada
- Université de Montréal, Montréal, Quebec, Canada
- Cardiac Growth and Differentiation Unit, Institut de recherches cliniques de Montréal (IRCM), 110, avenue des Pins Ouest, Montréal, Quebec, Canada H2W 1R7. Tel.: +1 514 987 5680; Fax: +1 514 987 5575; E-mail:
| | - Mona Nemer
- Institut de recherches cliniques de Montréal (IRCM), Montréal, Quebec, Canada
- Université de Montréal, Montréal, Quebec, Canada
- Cardiac Growth and Differentiation Unit, Institut de recherches cliniques de Montréal (IRCM), 110, avenue des Pins Ouest, Montréal, Quebec, Canada H2W 1R7. Tel.: +1 514 987 5680; Fax: +1 514 987 5575; E-mail:
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10
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Edwards JG. In Vivo beta-adrenergic activation of atrial natriuretic factor (ANF) reporter expression. Mol Cell Biochem 2006; 292:119-29. [PMID: 16909307 DOI: 10.1007/s11010-006-9225-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2005] [Accepted: 05/01/2006] [Indexed: 11/29/2022]
Abstract
Isoproterenol (ISO) infusion increases ANF-mRNA levels and control of ANF expression lies at the level of transcription. In neonatal cardiomyocytes, previous investigations determined that the -125 to -100 region of the rat ANF 5' flanking region contained cis-elements critical for control of ISO induced ANF transcription. However, it is unclear if these same cis-elements regulate ANF transcription in vivo. To examine this question, reporter plasmids containing the ANF 5' flanking/promoter region were injected directly into the left ventricle. Following a recovery period, osmotic pumps were implanted to infuse vehicle or ISO (0.2 or 2.0 mg/kg/d). ISO significantly (p < .05) increased the LV/BW ratio in a dose dependent, but not a time dependent manner. ISO significantly (p < .05) increased ANF reporter expression in both a dose-dependent and time dependent manner. Injections into the midwall of the LV or into the apex did not lead to significant differences in ISO-induced ANF reporter expression. Using site-specific mutations of ANF reporter constructs, comparisons were made of ISO induced ANF transcription in vitro in neonatal cardiomyocytes and in vivo in the adult heart. Cis-elements critical for ISO activation in cultured cardiomyocytes were not essential for the increased expression of the ANF reporters in vivo. The results indicate that distinct differences in ANF transcriptional regulation exist in vivo in the adult heart as compared with neonatal cardiomyocytes, and suggest the recruitment of other signaling pathways beyond adrenergic-receptor mediated pathways.
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Affiliation(s)
- J G Edwards
- Department of Physiology, New York Medical College, Valhalla, New York, USA.
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11
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Fischer A, Klattig J, Kneitz B, Diez H, Maier M, Holtmann B, Englert C, Gessler M. Hey basic helix-loop-helix transcription factors are repressors of GATA4 and GATA6 and restrict expression of the GATA target gene ANF in fetal hearts. Mol Cell Biol 2005; 25:8960-70. [PMID: 16199874 PMCID: PMC1265774 DOI: 10.1128/mcb.25.20.8960-8970.2005] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The Hey basic helix-loop-helix transcription factors are downstream effectors of Notch signaling in the cardiovascular system. Mice lacking Hey2 develop cardiac hypertrophy, often associated with congenital heart defects, whereas combined Hey1/Hey2 deficiency leads to severe vascular defects and embryonic lethality around embryonic day E9.5. The molecular basis of these disorders is poorly understood, however, since target genes of Hey transcription factors in the affected tissues remain elusive. To identify genes regulated by Hey factors we have generated a conditional Hey1 knockout mouse. This strain was used to generate paired Hey2- and Hey1/2-deficient embryonic stem cell lines. Comparison of these cell lines by microarray analysis identified GATA4 and GATA6 as differentially expressed genes. Loss of Hey1/2 leads to elevated GATA4/6 and ANF mRNA levels in embryoid bodies, while forced expression of Hey factors strongly represses expression of the GATA4 and GATA6 promoter in various cell lines. In addition, the promoter activity of the GATA4/6 target gene ANF was inhibited by Hey1, Hey2, and HeyL. Protein interaction and mutation analyses suggest that repression is due to direct binding of Hey proteins to GATA4 and GATA6, blocking their transcriptional activity. In Hey2-deficient fetal hearts we observed elevated mRNA levels of ANF and CARP. Expression of ANF and Hey2 is normally restricted to the trabecular and compact myocardial layer, respectively. Intriguingly, loss of Hey2 leads to ectopic ANF expression in the compact layer, suggesting a direct role for Hey2 in limiting ANF expression in this cardiac compartment.
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Affiliation(s)
- Andreas Fischer
- Theodor-Boveri-Institute, Physiological Chemistry I, University of Wuerzburg, Germany
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12
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Aries A, Paradis P, Lefebvre C, Schwartz RJ, Nemer M. Essential role of GATA-4 in cell survival and drug-induced cardiotoxicity. Proc Natl Acad Sci U S A 2004; 101:6975-80. [PMID: 15100413 PMCID: PMC406451 DOI: 10.1073/pnas.0401833101] [Citation(s) in RCA: 221] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
In recent years, significant progress has been made in understanding cardiomyocyte differentiation. However, little is known about the regulation of myocyte survival despite the fact that myocyte apoptosis is a leading cause of heart failure. Here we report that transcription factor GATA-4 is a survival factor for differentiated, postnatal cardiomyocytes and an upstream activator of the antiapoptotic gene Bcl-X. An early event in the cardiotoxic effect of the antitumor drug doxorubicin is GATA-4 depletion, which in turn causes cardiomyocyte apoptosis. Mouse heterozygotes for a null Gata4 allele have enhanced susceptibility to doxorubicin cardiotoxicity. Genetic or pharmacologic enhancement of GATA-4 prevents cardiomyocyte apoptosis and drug-induced cardiotoxicity. The results indicate that GATA-4 is an antiapoptotic factor required for the adaptive stress response of the adult heart. Modulation of survival/apoptosis genes by tissue-specific transcription factors may be a general paradigm that can be exploited effectively for cell-specific regulation of apoptosis in disease states.
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Affiliation(s)
- Anne Aries
- Laboratory of Cardiac Growth and Differentiation, Institut de Recherches Cliniques de Montréal, Montréal, QC, Canada H2W 1R7
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13
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Habets PEMH, Moorman AFM, Clout DEW, van Roon MA, Lingbeek M, van Lohuizen M, Campione M, Christoffels VM. Cooperative action of Tbx2 and Nkx2.5 inhibits ANF expression in the atrioventricular canal: implications for cardiac chamber formation. Genes Dev 2002; 16:1234-46. [PMID: 12023302 PMCID: PMC186286 DOI: 10.1101/gad.222902] [Citation(s) in RCA: 255] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
During heart development, chamber myocardium forms locally from the embryonic myocardium of the tubular heart. The atrial natriuretic factor (ANF) gene is specifically expressed in this developing chamber myocardium and is one of the first hallmarks of chamber formation. We investigated the regulatory mechanism underlying this selective expression. Transgenic analysis shows that a small fragment of the ANF gene is responsible for the developmental pattern of endogenous ANF gene expression. Furthermore, this fragment is able to repress cardiac troponin I (cTnI) promoter activity selectively in the embryonic myocardium of the atrioventricular canal (AVC). In vivo inactivation of a T-box factor (TBE)- or NK2-homeobox factor binding element (NKE) within the ANF fragment removed the repression in the AVC without affecting its chamber activity. The T-box family member Tbx2, encoding a transcriptional repressor, is expressed in the embryonic myocardium in a pattern mutually exclusive to ANF, thus suggesting a role in the suppression of ANF. Tbx2 formed a complex with Nkx2.5 on the ANF TBE-NKE, and was able to repress ANF promoter activity. Our data provide a potential mechanism for chamber-restricted gene activity in which the cooperative action of Tbx2 and Nkx2.5 inhibits expression in the AVC.
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Affiliation(s)
- Petra E M H Habets
- Experimental and Molecular Cardiology Group, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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Tse MY, Watson JD, Sarda IR, Flynn TG, Pang SC. Expression of B-type natriuretic peptide in atrial natriuretic peptide gene disrupted mice. Mol Cell Biochem 2001; 219:99-105. [PMID: 11354260 DOI: 10.1023/a:1011087513774] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) are two hormones produced and secreted by the heart to control blood pressure, body fluid homeostasis and electrolyte balance. Each peptide binds to a common family of 3 receptors (GC-A, GC-B and C-receptor) with varying degrees of affinity. The proANP gene disrupted mouse model provides an excellent opportunity to examine the regulation and expression of BNP in the absence ofANP. A new radioimmunoassay (RIA) was developed in order to measure mouse BNP peptide levels in the plasma, atrium and ventricle of the mouse. A detection limit of 3-6 pg/tube was achieved by this assay. Results show that plasma and ventricular level of BNP were unchanged among the three genotypes of mice. However, a significant decrease in the BNP level was noted in the atrium. The homozygous mutant (ANP-/-) had undetectable levels of BNP in the atrium, while the heterozygous (ANP+/-) and wild-type (ANP+/+) mice had 430 and 910 pg/mg in the atrium, respectively. Northern Blot analysis shows the ANP-/- mice has a 40% reduction of BNP mRNA level in the atrium and a 5-fold increase in the ventricle as compared with that of the ANP+/+ mouse. Our data suggest that there is a compensatory response of BNP expression to proANP gene disruption. Despite the changes in the atrial and ventricular tissue mRNA and peptide levels, the plasma BNP level remains unaltered in the ANP-/- mice. We conclude that the inability of BNP to completely compensate for the lack of ANP eventually leads to chronic hypertension in the proANP gene disrupted mice.
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Affiliation(s)
- M Y Tse
- Department of Anatomy and Cell Biology, Queen 's University, Kingston, Ontario, Canada
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15
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Charron F, Tsimiklis G, Arcand M, Robitaille L, Liang Q, Molkentin JD, Meloche S, Nemer M. Tissue-specific GATA factors are transcriptional effectors of the small GTPase RhoA. Genes Dev 2001; 15:2702-19. [PMID: 11641276 PMCID: PMC312821 DOI: 10.1101/gad.915701] [Citation(s) in RCA: 184] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Rho-like GTPases play a pivotal role in the orchestration of changes in the actin cytoskeleton in response to receptor stimulation, and have been implicated in transcriptional activation, cell growth regulation, and oncogenic transformation. Recently, a role for RhoA in the regulation of cardiac contractility and hypertrophic cardiomyocyte growth has been suggested but the mechanisms underlying RhoA function in the heart remain undefined. We now report that transcription factor GATA-4, a key regulator of cardiac genes, is a nuclear mediator of RhoA signaling and is involved in the control of sarcomere assembly in cardiomyocytes. Both RhoA and GATA-4 are essential for sarcomeric reorganization in response to hypertrophic growth stimuli and overexpression of either protein is sufficient to induce sarcomeric reorganization. Consistent with convergence of RhoA and GATA signaling, RhoA potentiates the transcriptional activity of GATA-4 via a p38 MAPK-dependent pathway that phosphorylates GATA-4 activation domains and GATA binding sites mediate RhoA activation of target cardiac promoters. Moreover, a dominant-negative GATA-4 protein abolishes RhoA-induced sarcomere reorganization. The identification of transcription factor GATA-4 as a RhoA mediator in sarcomere reorganization and cardiac gene regulation provides a link between RhoA effects on transcription and cell remodeling.
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Affiliation(s)
- F Charron
- Laboratoire de développement et différenciation cardiaques, Institut de recherches cliniques de Montréal (IRCM), Montréal, Québec, Canada H2W 1R7
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16
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Morin S, Paradis P, Aries A, Nemer M. Serum response factor-GATA ternary complex required for nuclear signaling by a G-protein-coupled receptor. Mol Cell Biol 2001; 21:1036-44. [PMID: 11158291 PMCID: PMC99558 DOI: 10.1128/mcb.21.4.1036-1044.2001] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Endothelins are a family of biologically active peptides that are critical for development and function of neural crest-derived and cardiovascular cells. These effects are mediated by two G-protein-coupled receptors and involve transcriptional regulation of growth-responsive and/or tissue-specific genes. We have used the cardiac ANF promoter, which represents the best-studied tissue-specific endothelin target, to elucidate the nuclear pathways responsible for the transcriptional effects of endothelins. We found that cardiac-specific response to endothelin 1 (ET-1) requires the combined action of the serum response factor (SRF) and the tissue-restricted GATA proteins which bind over their adjacent sites, within a 30-bp ET-1 response element. We show that SRF and GATA proteins form a novel ternary complex reminiscent of the well-characterized SRF-ternary complex factor interaction required for transcriptional induction of c-fos in response to growth factors. In transient cotransfections, GATA factors and SRF synergistically activate atrial natriuretic factor and other ET-1-inducible promoters that contain both GATA and SRF binding sites. Thus, GATA factors may represent a new class of tissue-specific SRF accessory factors that account for muscle- and other cell-specific SRF actions.
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Affiliation(s)
- S Morin
- Laboratoire de Développment et Différenciation Cardiaques, Institut de Recherches Cliniques de Montréal, Université de Montréal, Montreal, Quebec, Canada
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17
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Morin S, Charron F, Robitaille L, Nemer M. GATA-dependent recruitment of MEF2 proteins to target promoters. EMBO J 2000; 19:2046-55. [PMID: 10790371 PMCID: PMC305697 DOI: 10.1093/emboj/19.9.2046] [Citation(s) in RCA: 254] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The myocyte enhancer factor-2 (MEF2) proteins are MADS-box transcription factors that are essential for differentiation of all muscle lineages but their mechanisms of action remain largely undefined. In mammals, the earliest site of MEF2 expression is the heart where the MEF2C isoform is detectable as early as embryonic day 7.5. Inactivation of the MEF2C gene causes cardiac developmental arrest and severe downregulation of a number of cardiac markers including atrial natriuretic factor (ANF). However, most of these promoters contain no or low affinity MEF2 binding sites and they are not significantly activated by any MEF2 proteins in heterologous cells suggesting a dependence on a cardiac-enriched cofactor for MEF2 action. We provide evidence that MEF2 proteins are recruited to target promoters by the cell-specific GATA transcription factors, and that MEF2 potentiates the transcriptional activity of this family of tissue-restricted zinc finger proteins. Functional MEF2/GATA-4 synergy involves physical interaction between the MEF2 DNA-binding domain and the carboxy zinc finger of GATA-4 and requires the activation domains of both proteins. However, neither MEF2 binding sites nor MEF2 DNA binding capacity are required for transcriptional synergy. The results unravel a novel pathway for transcriptional regulation by MEF2 and provide a molecular paradigm for elucidating the mechanisms of action of MEF2 in muscle and non-muscle cells.
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Affiliation(s)
- S Morin
- Laboratoire de développement et différenciation cardiaques, Institut de recherches cliniques de Montréal, 110 des Pins Ouest, Montréal, QC, H2W 1R7, Canada
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18
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Saadane N, Alpert L, Chalifour LE. Expression of immediate early genes, GATA-4, and Nkx-2.5 in adrenergic-induced cardiac hypertrophy and during regression in adult mice. Br J Pharmacol 1999; 127:1165-76. [PMID: 10455263 PMCID: PMC1566134 DOI: 10.1038/sj.bjp.0702676] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Adrenoreceptor agonists induce a hypertrophic phenotype in vitro and in vivo. To investigate the molecular remodeling in chronic cardiac hypertrophy we infused adult male mice with vehicle. isoproterenol, phenylephrine or both agonists for 3, 7 or 14 days. All drugs increased cardiac mass. After minipump removal cardiac mass regressed to control levels within 7 days after PE and ISO treatment whereas ISO + PE treated hearts were incompletely regressed. ANF and beta-MHC, but not alpha-MHC, expression were increased by agonists at all time points. GATA-4, Nkx-2.5, Egr-1, c-jun and c-fos expression were increased after 3, 7 and 14 days of treatment. Expression was greatest after ISO+PE> >ISO>PE>vehicle infusion suggesting a synergistic effect of adrenoreceptor stimulation and indicating a greater effect of beta- than alpha-adrenergic action in vivo. After PE or ISO drug withdrawal the HW/BW was normal and Egr-1, c-jun, c-fos and GATA-4, but not Nkx2.5, expression dropped to control levels. HW/BW regression was incomplete after ISO+PE and elevated levels of Egr-1, c-jun and Nkx2.5 expression remained. A hydralazine-mediated reduction in blood pressure had no effect on the agonist-induced cardiac hypertrophy or gene expression. In conclusion, we found that continued agonist stimulation, and not blood pressure. is responsible for the maintained increase in gene expression. Further, we found the decrease in gene expression in the regression after drug withdrawal was gene specific.
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Affiliation(s)
- Nacéra Saadane
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis–Jewish General Hospital, 3755 chemin Côte Sainte Catherine, Montréal, Québec, Canada, H3T 1E2
| | - Lesley Alpert
- Department of Pathology, Sir Mortimer B. Davis–Jewish General Hospital, 3755 chemin Côte Sainte Catherine, Montréal, Québec, Canada, H3T 1E2
| | - Lorraine E Chalifour
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis–Jewish General Hospital, 3755 chemin Côte Sainte Catherine, Montréal, Québec, Canada, H3T 1E2
- Division of Experimental Medicine, Department of Medicine, McGill University, Montréal, Québec, Canada, H3A 1A3
- Author for correspondence:
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19
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Lu JR, McKinsey TA, Xu H, Wang DZ, Richardson JA, Olson EN. FOG-2, a heart- and brain-enriched cofactor for GATA transcription factors. Mol Cell Biol 1999; 19:4495-502. [PMID: 10330188 PMCID: PMC104407 DOI: 10.1128/mcb.19.6.4495] [Citation(s) in RCA: 165] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Members of the GATA family of zinc finger transcription factors have been shown to play important roles in the control of gene expression in a variety of cell types. GATA-1, -2, and -3 are expressed primarily in hematopoietic cell lineages and are required for proliferation and differentiation of multiple hematopoietic cell types, whereas GATA-4, -5, and -6 are expressed in the heart, where they activate cardiac muscle structural genes. Friend of GATA-1 (FOG) is a multitype zinc finger protein that interacts with GATA-1 and serves as a cofactor for GATA-1-mediated transcription. FOG is coexpressed with GATA-1 in developing erythroid and megakaryocyte cell lineages and cooperates with GATA-1 to control erythropoiesis. We describe a novel FOG-related factor, FOG-2, that is expressed predominantly in the developing and adult heart, brain, and testis. FOG-2 interacts with GATA factors, and interaction of GATA-4 and FOG-2 results in either synergistic activation or repression of GATA-dependent cardiac promoters, depending on the specific promoter and the cell type in which they are tested. The properties of FOG-2 suggest its involvement in the control of cardiac and neural gene expression by GATA transcription factors.
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Affiliation(s)
- J R Lu
- Departments of Molecular Biology and Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75235-9148, USA
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20
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Charron F, Paradis P, Bronchain O, Nemer G, Nemer M. Cooperative interaction between GATA-4 and GATA-6 regulates myocardial gene expression. Mol Cell Biol 1999; 19:4355-65. [PMID: 10330176 PMCID: PMC104395 DOI: 10.1128/mcb.19.6.4355] [Citation(s) in RCA: 176] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two members of the GATA family of transcription factors, GATA-4 and GATA-6, are expressed in the developing and postnatal myocardium and are equally potent transactivators of several cardiac promoters. However, several in vitro and in vivo lines of evidence suggest distinct roles for the two factors in the heart. Since identification of the endogenous downstream targets of GATA factors would greatly help to elucidate their exact functions, we have developed an adenovirus-mediated antisense strategy to specifically inhibit GATA-4 and GATA-6 protein production in postnatal cardiomyocytes. Expression of several endogenous cardiac genes was significantly down-regulated in cells lacking GATA-4 or GATA-6, indicating that these factors are required for the maintenance of the cardiac genetic program. Interestingly, transcription of some genes like the alpha- and beta-myosin heavy-chain (alpha- and beta-MHC) genes was preferentially regulated by GATA-4 due, in part, to higher affinity of GATA-4 for their promoter GATA element. However, transcription of several other genes, including the atrial natriuretic factor and B-type natriuretic peptide (ANF and BNP) genes, was similarly down-regulated in cardiomyocytes lacking one or both GATA factors, suggesting that GATA-4 and GATA-6 could act through the same transcriptional pathway. Consistent with this, GATA-4 and GATA-6 were found to colocalize in postnatal cardiomyocytes and to interact functionally and physically to provide cooperative activation of the ANF and BNP promoters. The results identify for the first time bona fide in vivo targets for GATA-4 and GATA-6 in the myocardium. The data also show that GATA factors act in concert to regulate distinct subsets of genes, suggesting that combinatorial interactions among GATA factors may differentially control various cellular processes.
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Affiliation(s)
- F Charron
- Laboratoire de Développement et Différenciation Cardiaques, Institut de Recherches Cliniques de Montréal, Montréal, Québec, Canada
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21
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Wang GF, Nikovits W, Schleinitz M, Stockdale FE. A positive GATA element and a negative vitamin D receptor-like element control atrial chamber-specific expression of a slow myosin heavy-chain gene during cardiac morphogenesis. Mol Cell Biol 1998; 18:6023-34. [PMID: 9742119 PMCID: PMC109188 DOI: 10.1128/mcb.18.10.6023] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/1998] [Accepted: 07/13/1998] [Indexed: 11/20/2022] Open
Abstract
We have used the slow myosin heavy chain (MyHC) 3 gene to study the molecular mechanisms that control atrial chamber-specific gene expression. Initially, slow MyHC 3 is uniformly expressed throughout the tubular heart of the quail embryo. As cardiac development proceeds, an anterior-posterior gradient of slow MyHC 3 expression develops, culminating in atrial chamber-restricted expression of this gene following chamberization. Two cis elements within the slow MyHC 3 gene promoter, a GATA-binding motif and a vitamin D receptor (VDR)-like binding motif, control chamber-specific expression. The GATA element of the slow MyHC 3 is sufficient for expression of a heterologous reporter gene in both atrial and ventricular cardiomyocytes, and expression of GATA-4, but not Nkx2-5 or myocyte enhancer factor 2C, activates reporter gene expression in fibroblasts. Equivalent levels of GATA-binding activity were found in extracts of atrial and ventricular cardiomyocytes from embryonic chamberized hearts. These observations suggest that GATA factors positively regulate slow MyHC 3 gene expression throughout the tubular heart and subsequently in the atria. In contrast, an inhibitory activity, operating through the VDR-like element, increased in ventricular cardiomyocytes during the transition of the heart from a tubular to a chambered structure. Overexpression of the VDR, acting via the VDR-like element, duplicates the inhibitory activity in ventricular but not in atrial cardiomyocytes. These data suggest that atrial chamber-specific expression of the slow MyHC 3 gene is achieved through the VDR-like inhibitory element in ventricular cardiomyocytes at the time distinct atrial and ventricular chambers form.
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Affiliation(s)
- G F Wang
- Department of Medicine, Stanford University School of Medicine, Stanford, California 94305-5115, USA
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22
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Lee Y, Shioi T, Kasahara H, Jobe SM, Wiese RJ, Markham BE, Izumo S. The cardiac tissue-restricted homeobox protein Csx/Nkx2.5 physically associates with the zinc finger protein GATA4 and cooperatively activates atrial natriuretic factor gene expression. Mol Cell Biol 1998; 18:3120-9. [PMID: 9584153 PMCID: PMC108894 DOI: 10.1128/mcb.18.6.3120] [Citation(s) in RCA: 208] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Specification and differentiation of the cardiac muscle lineage appear to require a combinatorial network of many factors. The cardiac muscle-restricted homeobox protein Csx/Nkx2.5 (Csx) is expressed in the precardiac mesoderm as well as the embryonic and adult heart. Targeted disruption of Csx causes embryonic lethality due to abnormal heart morphogenesis. The zinc finger transcription factor GATA4 is also expressed in the heart and has been shown to be essential for heart tube formation. GATA4 is known to activate many cardiac tissue-restricted genes. In this study, we tested whether Csx and GATA4 physically associate and cooperatively activate transcription of a target gene. Coimmunoprecipitation experiments demonstrate that Csx and GATA4 associate intracellularly. Interestingly, in vitro protein-protein interaction studies indicate that helix III of the homeodomain of Csx is required to interact with GATA4 and that the carboxy-terminal zinc finger of GATA4 is necessary to associate with Csx. Both regions are known to directly contact the cognate DNA sequences. The promoter-enhancer region of the atrial natriuretic factor (ANF) contains several putative Csx binding sites and consensus GATA4 binding sites. Transient-transfection assays indicate that Csx can activate ANF reporter gene expression to the same extent that GATA4 does in a DNA binding site-dependent manner. Coexpression of Csx and GATA4 synergistically activates ANF reporter gene expression. Mutational analyses suggest that this synergy requires both factors to fully retain their transcriptional activities, including the cofactor binding activity. These results demonstrate the first example of homeoprotein and zinc finger protein interaction in vertebrates to cooperatively regulate target gene expression. Such synergistic interaction among tissue-restricted transcription factors may be an important mechanism to reinforce tissue-specific developmental pathways.
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Affiliation(s)
- Y Lee
- Cardiovascular Research Center, University of Wisconsin Medical School, Madison, Wisconsin 53706, USA
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23
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Jans SW, de Jong YF, Reutelingsperger CP, van der Vusse GJ, van Bilsen M. Differential expression and localization of annexin V in cardiac myocytes during growth and hypertrophy. Mol Cell Biochem 1998; 178:229-36. [PMID: 9546604 DOI: 10.1023/a:1006803900554] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Recently it was shown that annexin V is the most prominent member of the annexin family in the adult heart [1]. Amongst others, annexin V has been suggested to play a role in developmental processes. The aim of the present study was to explore whether in the heart annexin V content and localization change during maturational and hypertrophic growth, in order to obtain indications that annexin V is involved in cardiac growth processes. First, in the intact rat heart annexin V content and localization were studied during perinatal development. It was clearly demonstrated that annexin V content in total heart transiently increased in the first week after birth, from 0.79 +/- 0.06 microg/mg protein at 1 day before birth to a peak value of 1.24 +/- 0.08 microg/mg protein 6 days after birth, whereafter annexin V protein levels declined to a value of 0.70 +/- 0.06 microg/mg protein at 84 days after birth (p < 0.05). Differences in annexin V content were also observed between myocytes isolated from neonatal and adult hearts [0.81 +/- 0.09 and 0.17 +/- 0.08 microg/mg protein, respectively (p < 0.05)]. Moreover, during cardiac maturational growth the subcellular localization of annexin V might change from a cytoplasmic to a more prominent sarcolemmal localization. Second, in vivo hypertrophy induced by aortic coarctation resulted in a marked degree of hypertrophy (22% increase in ventricular weight), but was not associated with a change in annexin V localization or content. The quantitative results obtained with intact hypertrophic rat hearts are supported by findings in neonatal ventricular myocytes, in which hypertrophy was induced by phenylephrine (10(-5) M). In the latter model no changes in annexin V content could be observed either. In conclusion, the marked alterations in annexin V content during the maturational growth in the heart suggest a possible involvement of this protein in this process. In contrast, the absence of changes in annexin V content and localization in hypertrophied hearts compared to age matched control hearts suggests that annexin V does not play a crucial role in the maintenance of the hypertrophic phenotype of the cardiac muscle cell. This notion is supported by observations in phenylephrine-induced hypertrophied neonatal cardiomyocytes.
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Affiliation(s)
- S W Jans
- Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, The Netherlands
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24
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Durocher D, Charron F, Warren R, Schwartz RJ, Nemer M. The cardiac transcription factors Nkx2-5 and GATA-4 are mutual cofactors. EMBO J 1997; 16:5687-96. [PMID: 9312027 PMCID: PMC1170200 DOI: 10.1093/emboj/16.18.5687] [Citation(s) in RCA: 499] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The tissue-restricted GATA-4 transcription factor and Nkx2-5 homeodomain protein are two early markers of precardiac cells. Both are essential for heart formation, but neither can initiate cardiogenesis. Overexpression of GATA-4 or Nkx2-5 enhances cardiac development in committed precursors, suggesting each interacts with a cardiac cofactor. We tested whether GATA-4 and Nkx2-5 are cofactors for each other by using transcription and binding assays with the cardiac atrial natriuretic factor (ANF) promoter_the only known target for Nkx2-5. Co-expression of GATA-4 and Nkx2-5 resulted in synergistic activation of the ANF promoter in heterologous cells. The synergy involves physical Nkx2-5-GATA-4 interaction, seen in vitro and in vivo, which maps to the C-terminal zinc finger of GATA-4 and a C-terminus extension; similarly, a C-terminally extended homeodomain of Nkx2-5 is required for GATA-4 binding. Structure/function studies suggest that binding of GATA-4 to the C-terminus autorepressive domain of Nkx2-5 may induce a conformational change that unmasks Nkx2-5 activation domains. GATA-6 cannot substitute for GATA-4 for interaction with Nkx2-5. This interaction may impart functional specificity to GATA factors and provide cooperative crosstalk between two pathways critical for early cardiogenesis. Given the co-expression of GATA proteins and NK2 class members in other tissues, the GATA/Nkx partnership may represent a paradigm for transcription factor interaction during organogenesis.
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Affiliation(s)
- D Durocher
- Laboratoire de Développement et Différenciation Cardiaques, Institut de Recherches Cliniques de Montréal, 110 des Pins Ouest, Montréal Qu-ebec, Canada H2W 1R7
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25
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von Harsdorf R, Edwards JG, Shen YT, Kudej RK, Dietz R, Leinwand LA, Nadal-Ginard B, Vatner SF. Identification of a cis-acting regulatory element conferring inducibility of the atrial natriuretic factor gene in acute pressure overload. J Clin Invest 1997; 100:1294-304. [PMID: 9276748 PMCID: PMC508307 DOI: 10.1172/jci119643] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
To identify the cis-acting regulatory element(s) which control the induction of the atrial natriuretic factor (ANF) gene in acute pressure overload, DNA constructs consisting of promoter elements linked to a reporter gene were injected into the myocardium of dogs, which underwent aortic banding or were sham-operated. Expression of a reporter gene construct harboring the ANF promoter (-3400ANF) was induced 6-12-fold after 7 d of pressure overload. An internal deletion of 556 bp (nucleotide sequence -693 to -137) completely abrogated the inducibility of the ANF reporter gene construct. An activator protein-1 (AP1)-like site (-496 to -489) and a cAMP regulatory element (CRE) (-602 to -596) are located within the deleted sequence. Site-directed mutagenesis of the AP1-like site but not the CRE completely prevented the induction of this construct to acute pressure overload. Further, the AP1-like site was able to confer inducibility of a heterologous promoter (beta-myosin heavy chain) to higher values than controls. Gel mobility shift assay (GMSA) supershift analysis was performed using a radiolabeled probe of the ANF promoter (-506/-483) that included the AP1-like site (ATGAATCA) sequence, as well as a probe converted to contain an AP1 consensus sequence (ATGACTCA). GMSA analysis demonstrated that the ANF AP1-like element could bind both a constitutively expressed factor and the AP1 proteins, and conversion to a true AP1 site increased its affinity for AP1. However, 7 d after the onset of pressure overload, the AP1 proteins were present only at low levels, and the major complex formed by the ANF AP1-like probe was not supershifted by a jun antibody. Using a large animal model of pressure overload, we have demonstrated that a unique cis-acting element was primarily responsible for the overload induction of the ANF gene.
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Affiliation(s)
- R von Harsdorf
- Franz Volhard Klinik und Max-Delbrück-Centrum, Humboldt Universität zu Berlin, Berlin, Germany 13 122
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26
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Durocher D, Chen CY, Ardati A, Schwartz RJ, Nemer M. The atrial natriuretic factor promoter is a downstream target for Nkx-2.5 in the myocardium. Mol Cell Biol 1996; 16:4648-55. [PMID: 8756621 PMCID: PMC231464 DOI: 10.1128/mcb.16.9.4648] [Citation(s) in RCA: 134] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The recently described NK2 family of homeodomain proteins are key developmental regulators. In Drosophila melanogaster, two members of this family, bagpipe and tinman, are required for visceral and cardiac mesoderm formation, respectively. In vertebrates, tinman appears to represent a family of closely related NK2 genes, including Nkx-2.5, that are expressed at an early stage in precardiac cells. Consistent with a role for Nkx-2.5 in heart development, inactivation of the Nkx-2.5 gene in mice causes severe cardiac malformations and embryonic lethality. However, little is known about the molecular action of Nkx-2.5 and its targets in cardiac muscle. In this paper, we report the identification and characterization of a functional and highly conserved Nkx-2.5 response element, termed the NKE, in the proximal region of the cardiac atrial natriuretic factor (ANF) promoter. The NKE is composed of two near-consensus NK2 binding sites that are each able to bind purified Nkx-2.5. The NKE is sufficient to confer cardiac cell-specific activity to a minimal TATA-containing promoter and is required for Nkx-2.5 activation of the ANF promoter in heterologous cells. Interestingly, in primary cardiocyte cultures, the NKE contributes to ANF promoter activity in a chamber- and developmental stage-specific manner, suggesting that Nkx-2.5 and/or other related cardiac proteins may play a role in chamber specification. This work provides the identification of a direct target for NK2 homeoproteins in the heart and lays the foundation for further molecular analyses of the role of Nkx-2.5 and other NK2 proteins in cardiac development.
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Affiliation(s)
- D Durocher
- Laboratoire de Développement et Différenciation Cardiaques, Institut de Recherches Cliniques de Montréal, Quebec, Canada
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27
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Knowlton KU, Rockman HA, Itani M, Vovan A, Seidman CE, Chien KR. Divergent pathways mediate the induction of ANF transgenes in neonatal and hypertrophic ventricular myocardium. J Clin Invest 1995; 96:1311-8. [PMID: 7657806 PMCID: PMC185753 DOI: 10.1172/jci118166] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
To determine whether similar or divergent pathways mediate atrial natriuretic factor (ANF) induction in neonatal and hypertrophied adult ventricular myocardium, and to assess whether studies using an in vitro model system of hypertrophy have fidelity to the in vivo context during pressure overload hypertrophy, we generated transgenic mice which harbor either 638 or 3,003 bp of the rat ANF 5' flanking region ligated upstream from a luciferase reporter. Luciferase activity in the ventricles of day 1 transgenic neonates was 8-24-fold higher than the levels expressed in the ventricles of adult mice. Adult mice expressed the luciferase reporter in an appropriate tissue-specific manner. Transverse aortic constriction of adult mice harboring ANF reporter transgenes demonstrated no significant increase in reporter activity in the ventricle. These findings demonstrate that distinct regions of the ANF 5'-flanking region are required for inducible expression of the ANF gene in the hypertrophic adult ventricle compared with those required for atrial-specific and developmentally appropriate expression in the intact neonatal heart. Furthermore, the cis regulatory elements necessary for induction of ANF expression in endothelin-1 or alpha 1-adrenergically stimulated cultured neonatal ventricular myocytes are not sufficient for induction in the in vivo context of pressure overload hypertrophy.
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Affiliation(s)
- K U Knowlton
- Department of Medicine, University of California, San Diego, School of Medicine, La Jolla 92093, USA
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28
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Grépin C, Robitaille L, Antakly T, Nemer M. Inhibition of transcription factor GATA-4 expression blocks in vitro cardiac muscle differentiation. Mol Cell Biol 1995; 15:4095-102. [PMID: 7623805 PMCID: PMC230648 DOI: 10.1128/mcb.15.8.4095] [Citation(s) in RCA: 141] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Commitment of mesodermal cells to the cardiac lineage is a very early event that occurs during gastrulation, and differentiation of cardiac muscle cells begins in the presomite stage prior to formation of the beating heart tube. However, the molecular events, including gene products that are required for differentiation of cardiac muscle cells, remain essentially unknown. GATA-4 is a recently characterized cardiac muscle-restricted transcription factor whose properties suggest an important regulatory role in heart development. We tested the role of GATA-4 in cardiac differentiation, using the pluripotent P19 embryonal carcinoma cells, which can be differentiated into beating cardiac muscle cells. In this system, GATA-4 transcripts and protein are restricted to cells committed to the cardiac lineage, and induction of GATA-4 precedes expression of cardiac marker genes and appearance of beating cells. Inhibition of GATA-4 expression by antisense transcripts blocks development of beating cardiac muscle cells and interferes with expression of cardiac muscle markers. These data indicate that GATA-4 is necessary for development of cardiac muscle cells and identify for the first time a tissue-specific transcription factor that may be crucial for early steps of mammalian cardiogenesis.
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Affiliation(s)
- C Grépin
- Laboratoire de Développement et Différenciation Cardiaques, Université de Montréal, Québec, Canada
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29
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The GATA-4 transcription factor transactivates the cardiac muscle-specific troponin C promoter-enhancer in nonmuscle cells. Mol Cell Biol 1994. [PMID: 7935467 DOI: 10.1128/mcb.14.11.7517] [Citation(s) in RCA: 117] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The unique contractile phenotype of cardiac myocytes is determined by the expression of a set of cardiac muscle-specific genes. By analogy to other mammalian developmental systems, it is likely that the coordinate expression of cardiac genes is controlled by lineage-specific transcription factors that interact with promoter and enhancer elements in the transcriptional regulatory regions of these genes. Although previous reports have identified several cardiac muscle-specific transcriptional elements, relatively little is known about the lineage-specific transcription factors that regulate these elements. In this report, we demonstrate that the slow/cardiac muscle-specific troponin C (cTnC) enhancer contains a specific binding site for the lineage-restricted zinc finger transcription factor GATA-4. This GATA-4-binding site is required for enhancer activity in primary cardiac myocytes. Moreover, the cTnC enhancer can be transactivated by overexpression of GATA-4 in non-cardiac muscle cells such as NIH 3T3 cells. In situ hybridization studies demonstrate that GATA-4 and cTnC have overlapping patterns of expression in the hearts of postimplantation mouse embryos and that GATA-4 gene expression precedes cTnC expression. Indirect immunofluorescence reveals GATA-4 expression in cultured cardiac myocytes from neonatal rats. Taken together, these results are consistent with a model in which GATA-4 functions to direct tissue-specific gene expression during mammalian cardiac development.
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30
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Ip HS, Wilson DB, Heikinheimo M, Tang Z, Ting CN, Simon MC, Leiden JM, Parmacek MS. The GATA-4 transcription factor transactivates the cardiac muscle-specific troponin C promoter-enhancer in nonmuscle cells. Mol Cell Biol 1994; 14:7517-26. [PMID: 7935467 PMCID: PMC359288 DOI: 10.1128/mcb.14.11.7517-7526.1994] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The unique contractile phenotype of cardiac myocytes is determined by the expression of a set of cardiac muscle-specific genes. By analogy to other mammalian developmental systems, it is likely that the coordinate expression of cardiac genes is controlled by lineage-specific transcription factors that interact with promoter and enhancer elements in the transcriptional regulatory regions of these genes. Although previous reports have identified several cardiac muscle-specific transcriptional elements, relatively little is known about the lineage-specific transcription factors that regulate these elements. In this report, we demonstrate that the slow/cardiac muscle-specific troponin C (cTnC) enhancer contains a specific binding site for the lineage-restricted zinc finger transcription factor GATA-4. This GATA-4-binding site is required for enhancer activity in primary cardiac myocytes. Moreover, the cTnC enhancer can be transactivated by overexpression of GATA-4 in non-cardiac muscle cells such as NIH 3T3 cells. In situ hybridization studies demonstrate that GATA-4 and cTnC have overlapping patterns of expression in the hearts of postimplantation mouse embryos and that GATA-4 gene expression precedes cTnC expression. Indirect immunofluorescence reveals GATA-4 expression in cultured cardiac myocytes from neonatal rats. Taken together, these results are consistent with a model in which GATA-4 functions to direct tissue-specific gene expression during mammalian cardiac development.
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Affiliation(s)
- H S Ip
- Department of Medicine, University of Chicago, IL 60637
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31
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A hormone-encoding gene identifies a pathway for cardiac but not skeletal muscle gene transcription. Mol Cell Biol 1994. [PMID: 8164667 DOI: 10.1128/mcb.14.5.3115] [Citation(s) in RCA: 155] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
In contrast to skeletal muscle, the mechanisms responsible for activation and maintenance of tissue-specific transcription in cardiac muscle remain poorly understood. A family of hormone-encoding genes is expressed in a highly specific manner in cardiac but not skeletal myocytes. This includes the A- and B-type natriuretic peptide (ANP and BNP) genes, which encode peptide hormones with crucial roles in the regulation of blood volume and pressure. Since these genes are markers of cardiac cells, we have used them to probe the mechanisms for cardiac muscle-specific transcription. Cloning and functional analysis of the rat BNP upstream sequences revealed unexpected structural resemblance to erythroid but not to muscle-specific promoters and enhancers, including a requirement for regulatory elements containing GATA motifs. A cDNA clone corresponding to a member of the GATA family of transcription factors was isolated from a cardiomyocyte cDNA library. Transcription of this GATA gene is restricted mostly to the heart and is undetectable in skeletal muscle. Within the heart, GATA transcripts are localized in ANP- and BNP-expressing myocytes, and forced expression of the GATA protein in heterologous cells markedly activates transcription from the natural cardiac muscle-specific ANP and BNP promoters. This GATA-dependent pathway defines the first mechanism for cardiac muscle-specific transcription. Moreover, the present findings reveal striking similarities between the mechanisms controlling gene expression in hematopoietic and cardiac cells and may have important implications for studies of cardiogenesis.
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32
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Grépin C, Dagnino L, Robitaille L, Haberstroh L, Antakly T, Nemer M. A hormone-encoding gene identifies a pathway for cardiac but not skeletal muscle gene transcription. Mol Cell Biol 1994; 14:3115-29. [PMID: 8164667 PMCID: PMC358679 DOI: 10.1128/mcb.14.5.3115-3129.1994] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
In contrast to skeletal muscle, the mechanisms responsible for activation and maintenance of tissue-specific transcription in cardiac muscle remain poorly understood. A family of hormone-encoding genes is expressed in a highly specific manner in cardiac but not skeletal myocytes. This includes the A- and B-type natriuretic peptide (ANP and BNP) genes, which encode peptide hormones with crucial roles in the regulation of blood volume and pressure. Since these genes are markers of cardiac cells, we have used them to probe the mechanisms for cardiac muscle-specific transcription. Cloning and functional analysis of the rat BNP upstream sequences revealed unexpected structural resemblance to erythroid but not to muscle-specific promoters and enhancers, including a requirement for regulatory elements containing GATA motifs. A cDNA clone corresponding to a member of the GATA family of transcription factors was isolated from a cardiomyocyte cDNA library. Transcription of this GATA gene is restricted mostly to the heart and is undetectable in skeletal muscle. Within the heart, GATA transcripts are localized in ANP- and BNP-expressing myocytes, and forced expression of the GATA protein in heterologous cells markedly activates transcription from the natural cardiac muscle-specific ANP and BNP promoters. This GATA-dependent pathway defines the first mechanism for cardiac muscle-specific transcription. Moreover, the present findings reveal striking similarities between the mechanisms controlling gene expression in hematopoietic and cardiac cells and may have important implications for studies of cardiogenesis.
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Affiliation(s)
- C Grépin
- Laboratoire de Développement et Différenciation Cardiaques, Institut de Recherches Cliniques de Montréal, Québec, Canada
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