Abstract: Neurogenin 3 (NGN3) is a key transcription factor in the pancreatic endocrine cell development. Transient expression of NGN3 is essential for transition of endocrine progenitors (EPs) into endocrine cells (ECs). It is known that the transcriptional activity of NGN3 and its degradation are regulated by post-translational modifications such as phosphorylation. By using knockout system of protein arginine methyltransferase-1 (PRMT-1) in human embryonic stem cells (hESCs), recently, we found that methylation on 65 arginine of NGN3 is crucial for its transcriptional activity and rapid degradation. In this study, we hypothesized whether PRMT-1 inhibition supports the development of hESCs into pancreatic endocrine lineage. To address this question, hESC-derived EPs were transiently treated with a PRMT-1 inhibitor X and then cultured until the EC stage. As results, transient PRMT-1 inhibition increased expression levels of EP-specific markers (NGN3, NEUROD1 and PAX6) in the EPs, and enhanced the transcriptional expression of EC-associated genes such as INS and MAFA in the ECs. Proportion of ECs expressing c-peptide was significantly enhanced in the PRMT-1 inhibition group compared to the non-treated group. Furthermore, pancreatic islet-like organoids (PIOs) developed from the ECs secreted human insulin upon glucose stimulation. Collectively, our findings demonstrate that transient inhibition of PRMT-1 in EPs can induce efficient differentiation of ECs during pancreatic development of hESCs in vitro.
Funding Source: Korea Fund for Regenerative Medicine
