The histone trimethyllysine demethylase JMJD2A promotes cardiac hypertrophy in response to hypertrophic stimuli in mice
Qing-Jun Zhang, … , Joseph A. Hill, Zhi-Ping Liu
Qing-Jun Zhang, … , Joseph A. Hill, Zhi-Ping Liu
Published May 9, 2011
Citation Information: J Clin Invest. 2011;121(6):2447-2456. https://doi.org/10.1172/JCI46277.
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The histone trimethyllysine demethylase JMJD2A promotes cardiac hypertrophy in response to hypertrophic stimuli in mice

Abstract

Cardiac hypertrophy and failure are accompanied by a reprogramming of gene expression that involves transcription factors and chromatin remodeling enzymes. Little is known about the roles of histone methylation and demethylation in this process. To understand the role of JMJD2A, a histone trimethyl demethylase, in cardiac hypertrophy, we generated mouse lines with heart-specific Jmjd2a deletion (hKO) and overexpression (Jmjd2a-Tg). Jmjd2a hKO and Jmjd2a-Tg mice had no overt baseline phenotype, but did demonstrate altered responses to cardiac stresses. While inactivation of Jmjd2a resulted in an attenuated hypertrophic response to transverse aortic constriction–induced (TAC-induced) pressure overload, Jmjd2a-Tg mice displayed exacerbated cardiac hypertrophy. We identified four-and-a-half LIM domains 1 (FHL1), a key component of the mechanotransducer machinery in the heart, as a direct target of JMJD2A. JMJD2A bound to the FHL1 promoter in response to TAC, upregulated FHL1 expression, and downregulated H3K9 trimethylation. Upregulation of FHL1 by JMJD2A was mediated through SRF and myocardin and required its demethylase activity. The expression of JMJD2A was upregulated in human hypertrophic cardiomyopathy patients. Our studies reveal that JMJD2A promotes cardiac hypertrophy under pathological conditions and suggest what we believe to be a novel mechanism for JMJD2A in reprogramming of gene expression involved in cardiac hypertrophy.

Authors

Qing-Jun Zhang, Hou-Zao Chen, Lin Wang, De-Pei Liu, Joseph A. Hill, Zhi-Ping Liu

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Figure 6

JMJD2A upregulates FHL1 transcription synergistically with SRF/myocardin.

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JMJD2A upregulates FHL1 transcription synergistically with SRF/myocardin...
(A) A 32P-labeled oligonucleotide probe containing the CArG box from the FHL1 promoter was incubated with the in vitro–translated (ivt) SRF in the presence or absence of anti-SRF antibody or a 100-fold molar excess of unlabeled, WT, or mutant (mut) oligonucleotides. SRF forms a complex with the WT oligonucleotide probe (SRF-CArG) that can be super-shifted (ss) by an anti-SRF antibody. ns, nonspecific nucleoprotein complex. (B) A 1.9-kb FHL1 promoter–driven luciferase construct was transfected along with the plasmids indicated into QBI293A cells. FHL1-luciferase activities were measured 24 hours after transfection and normalized against cotransfected β-galactosidase. (C) Responsiveness of the deletion and site-specific mutants of the FHL1-luc reporter to myocardin and JMJD2A in QBI293A cells. Deletion or site-specific mutation of the SRF-binding site CArG box impairs the responsiveness of the promoter to myocardin and JMJD2A. (D) Relative activity of the FHL1-luc reporter in SRF-null and WT ES cells in the presence and absence of cotransfected expression plasmids as indicated. Representative of 3 independent experiments is shown. (E) Relative luciferase activity of the ANP-luc reporter and (F) the sm22-luc reporter in QBI293A cells transfected with the plasmids indicated. Myocardin-activated ANP- and sm22-luc reporters that can be further upregulated by WT but not mutant JMJD2A. Data shown are mean ± SEM of 3 independent experiments. *P < 0.05.