A Loss of Function Screen of Epigenetic Modifiers and Splicing Factors during Early Stage of Cardiac Reprogramming

• Published in: Stem cells international Vol. 2018; no. 2018; pp. 1 - 14
• Main Authors: Qian, Li, Yin, Chaoying, Wall, Joseph B., Liu, Ziqing, Wang, Li, Alimohamadi, Sahar, Zhou, Yang, Liu, Jiandong
• Format: Journal Article
• Language: English
• Published: Cairo, Egypt Hindawi Publishing Corporation 01.01.2018; Hindawi; John Wiley & Sons, Inc; Hindawi Limited
• Subjects: Cardiomyocytes; Cell cycle; Cell division; Cell fate; Chromatin; Chromatin remodeling; Cohesin; Coronary artery disease; Deoxyribonucleic acid; Disease control; DNA; DNA methylation; Drug discovery; Efficiency; Embryo fibroblasts; Embryos; Epigenetic inheritance; Epigenetics; Ethylenediaminetetraacetic acid; Fibroblasts; Gene expression; Genes; Heart; Heart diseases; Molecular modelling; Regeneration; Ribonucleic acid; RNA; Splicing; Splicing factors; Stem cells; Transcription factors
• ISSN: 1687-966X; 1687-9678; 1687-9678
• DOI: 10.1155/2018/3814747

Direct reprogramming of cardiac fibroblasts (CFs) to induced cardiomyocytes (iCMs) is a newly emerged promising approach for cardiac regeneration, disease modeling, and drug discovery. However, its potential has been drastically limited due to the low reprogramming efficiency and largely unknown underlying molecular mechanisms. We have previously screened and identified epigenetic factors related to histone modification during iCM reprogramming. Here, we used shRNAs targeting an additional battery of epigenetic factors involved in chromatin remodeling and RNA splicing factors to further identify inhibitors and facilitators of direct cardiac reprogramming. Knockdown of RNA splicing factors Sf3a1 or Sf3b1 significantly reduced the percentage and total number of cardiac marker positive iCMs accompanied with generally repressed gene expression. Removal of another RNA splicing factor Zrsr2 promoted the acquisition of CM molecular features in CFs and mouse embryonic fibroblasts (MEFs) at both protein and mRNA levels. Moreover, a consistent increase of reprogramming efficiency was observed in CFs and MEFs treated with shRNAs targeting Bcor (component of BCOR complex superfamily) or Stag2 (component of cohesin complex). Our work thus reveals several additional epigenetic and splicing factors that are either inhibitory to or required for iCM reprogramming and highlights the importance of epigenetic regulation and RNA splicing process during cell fate conversion.