PRMT1 Is Required for the Maintenance of Mature β-Cell Identity

Area of Science:

• Endocrinology
• Molecular Biology
• Epigenetics

Background:

• Loss of functional pancreatic beta-cell mass is central to type 2 diabetes.
• Maintaining mature beta-cell identity is critical for preserving beta-cell mass and function.
• The mechanisms governing beta-cell identity maintenance remain incompletely understood.

Purpose of the Study:

• To investigate the role of protein arginine methyltransferase 1 (PRMT1) in maintaining mature beta-cell identity.
• To elucidate the molecular mechanisms by which PRMT1 influences beta-cell function and identity.

Main Methods:

• Gene knockout of *Prmt1* in fetal and adult mouse beta-cells.
• Assessment of diabetes development and metabolic stress response.
• Chromatin immunoprecipitation sequencing (ChIP-seq) and assay for transposase-accessible chromatin sequencing (ATAC-seq) analyses.
• Analysis of gene expression related to beta-cell function and identity.

Main Results:

• *Prmt1* knockout induced diabetes, exacerbated by high-fat diet.
• Deletion of *Prmt1* led to rapid loss of histone H4 arginine 3 asymmetric dimethylation (H4R3me2a) and beta-cell identity.
• PRMT1-dependent H4R3me2a regulates chromatin accessibility at key transcription factor binding sites.
• Downregulation of mature beta-cell function and identity genes was observed upon *Prmt1* deletion.
• PRMT1-mediated open chromatin regions correlate with human diabetes risk.

Conclusions:

• PRMT1 is essential for maintaining mature beta-cell identity.
• PRMT1 regulates beta-cell identity through epigenetic modifications, specifically H4R3me2a, influencing chromatin accessibility.
• These findings highlight PRMT1 as a potential therapeutic target for type 2 diabetes.