GSE117099
PRMT1-dependent histone arginine methylation regulates mature beta cell identity (ATAC-Seq)
Purpose: Loss of functional ß cell mass is an essential feature of type 2 diabetes and recent studies indicate that cell dedifferentiation can result in the loss of functional cell mass. However, the mechanism of cell dedifferentiation has not been elucidated due to the lack of appropriate animal model. Methods: Prmt1 floxed mice were crossed with Rip2-Cre and Pdx1-CreERT2 mice to generate Prmt1 KO and Prmt1 iKO mice. R26-eYFP mice were crossed for lineage tracing experiments and  cell sorting. All mice were backcrossed and maintained on a C57BL/6J background. Cre recombination for CreERT2 was induced by total 5 times intraperitoneal injections (75 mg/kg) of corn oil dissolved tamoxifen (T5648, Sigma-Aldrich) over 2 weeks. Results: Deletion of Prmt1 in mature cells resulted in the immediate loss of H4R3me2a which induced cell dedifferentiation and cell selective Prmt1 knock-out mice developed diabetes phenotype. H4R3me2a worked as an active histone code that increased chromatin accessibility at the binding sites for transcription factors including CTCF, NKX6.1, MAFA, PDX1 and NEUROD1. Conclusions: PRMT1-dependent open chromatin regions showed a strong association with the risk of diabetes in human. In conclusion, PRMT1 plays an essential role in maintaining ß cell identity by regulating chromatin accessibility. Overall design: mRNA profiles, H4R3me2a ChIP-seq, ATAC-seq and CTCF ChIP-seq of wild type (WT) and Prmt1 -/- mice or MIN6 cell line were generated by deep sequencing, in duplicate, using Illumina Hiseq.