Ppp1r1b-lncRNA inhibits PRC2 at myogenic regulatory genes to promote cardiac and skeletal muscle development in mouse and human
- Xuedong Kang1,2,
- Yan Zhao1,2,
- Glen Van Arsdell1,3,
- Stanley F. Nelson1,4,5,6 and
- Marlin Touma1,2,5,6,7,8,9
- 1Department of Pediatrics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095, USA
- 2Neonatal/Congenital Heart Laboratory, Cardiovascular Research Laboratory, University of California Los Angeles, Los Angeles, California 90095, USA
- 3Department of Cardiothoracic Surgery, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095, USA
- 4Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095, USA
- 5Department of Human Genetics, Institute of Precision Health, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095, USA
- 6Institute of Precision Health, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095, USA
- 7The Molecular Biology Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095, USA
- 8Children's Discovery and Innovation Institute, Department of Pediatrics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095, USA
- 9Eli and Edythe Broad Stem Cell Institute, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095, USA
- Corresponding author: mtouma{at}mednet.ucla.edu
Abstract
Long noncoding RNAs (lncRNAs) have emerged as critical epigenetic regulators and play important roles in cardiac development and congenital heart disease. In a previous study, we identified a novel lncRNA, Ppp1r1b, with expression highly correlated with myogenesis. However, the molecular mechanism that underlies Ppp1r1b-lncRNA function in myogenic regulation is unknown. By silencing Ppp1r1b-lncRNA, mouse C2C12 and human skeletal myoblasts failed to develop fully differentiated myotubes. Myogenic differentiation was also impaired in PPP1R1B-lncRNA deficient human-induced pluripotent stem cell-derived cardiomyocytes (hiPSCs-CMs). The expression of myogenic transcription factors, including MyoD, Myogenin, and Tbx5, as well as sarcomere proteins, was significantly suppressed in Ppp1r1b-lncRNA inhibited myoblast cells and neonatal mouse heart. Histone modification analysis revealed increased H3K27 tri-methylation at MyoD1 and Myogenin promoters in GapmeR treated C2C12 cells. Furthermore, Ppp1r1b-lncRNA was found to bind to Ezh2, and chromatin isolation by RNA purification (ChIRP) assay revealed enriched interaction of Ppp1r1b-lncRNA with Myod1 and Tbx5 promoters, suggesting that Ppp1r1b-lncRNA induces transcription of myogenic transcription factors by interacting with the polycomb repressive complex 2 (PRC2) at the chromatin interface. Correspondingly, the silencing of Ppp1r1b-lncRNA increased EZH2 binding at promoter regions of myogenic transcription factors. Therefore, our results suggest that Ppp1r1b-lncRNA promotes myogenic differentiation through competing for PRC2 binding with chromatin of myogenic master regulators during heart and skeletal muscle development.
Keywords
Footnotes
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Abbreviations: LncRNA, long noncoding RNA; ChIRP, chromatin isolation by RNA purification; PRC2, polycomb repressive complex 2; RIP, RNA immunoprecipitation; CHIP, chromatin immunoprecipitation; HiPSCs, human-induced pluripotent stem cells; sk-Fmhc, fast-skeletal myosin heavy chain; CHD, congenital heart defect
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Article is online at http://www.rnajournal.org/cgi/doi/10.1261/rna.073692.119.
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Freely available online through the RNA Open Access option.
- Received October 17, 2019.
- Accepted January 13, 2020.
This article, published in RNA, is available under a Creative Commons License (Attribution 4.0 International), as described at http://creativecommons.org/licenses/by/4.0/.
