Abstract
Introduction: Myogenic differentiation is essential to cardiac development as well as regeneration and repair in response to genetic lesions or injury in the context of cardiomyopathy and congenital heart defects (CHDs). We have previously shown that mouse Ppp1r1b-lncRNA modulates epigenetic features of myogenic master regulators through targeted interaction with histone-modifying complex and other co-factors. However, the molecular mechanisms that underlie human PPP1R1B-lncRNA -mediated regulation of cardiomyocyte differentiation remain unknown. Objectives: To elucidate the mechanisms by which human PPP1R1B-lncRNA regulates cardiomyocyte differentiation. Methods/Results: PPP1R1B-lncRNA possessed conserved function in promoting myogenic differentiation in human cardiac and skeletal myocytes and its expression was dysregulated in CHDs. Mechanistically, by silencing PPP1R1B-lncRNA , myogenic differentiation was impaired in PPP1R1B-lncRNA -deficient human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). The expressions of myogenic transcription factors, including GATA4 and TBX5 , as well as sarcomere proteins, including TNNT2 and MYOZ2, were significantly suppressed in PPP1R1B-lncRNA deficient hiPSC-CMs. Epigenetic analysis revealed increased H3K27 tri-methylation at TBX5 promoter in the PPP1R1B-lncRNA knockdown cardiac progenitors. PPP1R1B-lncRNA was found to bind to EZH2, the enzymatic core of the polycomb repressive complex (PRC2). Furthermore, chromatin isolation by RNA purification (ChIRP)-seq revealed enriched interaction of PPP1R1B-lncRNA with TBX5 , MEF2C, and GATA4 promoters. Meanwhile, chromatin immunoprecipitation (ChIP)-PCR demonstrated increased enrichments of EZH2 at TBX5 promoter in the PPP1R1B-lncRNA-depleted cells, resembling what was observed in the pre-differentiation state. Conclusions: Human PPP1R1B-lncRNA promotes cardiomyocyte differentiation via interactions with promoters of key cardiac transcription factors. PPP1R1B-lncRNA enhances chromatin accessibility at TBX5 promoter by interfering with PRC2 binding. Understanding PPP1R1B-lncRNA function in cardiomyocyte differentiation may lead to novel therapies for cardiopathies and CHDs.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
