Lamin A/C-dependent chromatin architecture safeguards naïve pluripotency to prevent aberrant cardiovascular cell fate and function[RNA-seq_CM]

Tight control of cell fate choices is crucial for normal development. Here we show that lamin A/C plays a key role in chromatin organization in embryonic stem cells (ESCs), which safeguards naïve pluripotency and ensures proper cell fate choices during cardiogenesis. We find major changes in chromatin compaction and localization of cardiac genes already in Lmna−/−ESCs resulting in precocious activation of a transcriptional program promoting cardiomyocyte versus endothelial cell fate, accompanied by premature cardiomyocyte differentiation, cell cycle withdrawal, and abnormal contractility. Gata4 is activated by lamin A/C loss and Gata4 silencing or haploinsufficiency rescues the aberrant cardiovascular cell fate choices induced by lamin A/C deficiency. Importantly, we observe divergent functions of lamin A/C in naïve pluripotent stem cells and cardiomyocytes, which has distinct contributions to the transcriptional alterations of patients with LMNA-associated cardiomyopathy. Thus, disruption of lamin A/C-dependent chromatin architecture in ESCs is a primary event in LMNA loss-of-function cardiomyopathy. Conrol and Lmna KO E14 Tg(Nkx2-5-EmGFP) mESCs were differentiated by hanging drop method.Day10 CMs were FACS-sorted by Nkx2-5+ GFP expression and performed RNA-seq.