Department of Biomedical Science, University of Copenhagen, Copenhagen, Denmark.
Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark.
Cell Death Dis. 2023 Jul 5;14(7):399. doi: 10.1038/s41419-023-05906-w.
Insufficient insulin secretion is a hallmark of type 2 diabetes and has been attributed to beta cell identity loss characterized by decreased expression of several key beta cell genes. The pro-inflammatory factor BMP-2 is upregulated in islets of Langerhans from individuals with diabetes and acts as an inhibitor of beta cell function and proliferation. Exposure to BMP-2 induces expression of Id1-4, Hes-1, and Hey-1 which are transcriptional regulators associated with loss of differentiation. The aim of this study was to investigate the mechanism by which BMP-2 induces beta cell dysfunction and loss of cell maturity. Mouse islets exposed to BMP-2 for 10 days showed impaired glucose-stimulated insulin secretion and beta cell proliferation. BMP-2-induced beta cell dysfunction was associated with decreased expression of cell maturity and proliferation markers specific to the beta cell such as Ins1, Ucn3, and Ki67 and increased expression of Id1-4, Hes-1, and Hey-1. The top 30 most regulated proteins significantly correlated with corresponding mRNA expression. BMP-2-induced gene expression changes were associated with a predominant reduction in acetylation of H3K27 and a decrease in NeuroD1 chromatin binding activity. These results show that BMP-2 induces loss of beta cell maturity and suggest that remodeling of H3K27ac and decreased NeuroD1 DNA binding activity participate in the effect of BMP-2 on beta cell dysfunction.
胰岛素分泌不足是 2 型糖尿病的一个标志,其特征是几种关键的β细胞基因表达减少,导致β细胞的身份丧失。促炎因子 BMP-2 在糖尿病患者的胰岛中上调,并作为β细胞功能和增殖的抑制剂。BMP-2 的暴露会诱导 Id1-4、Hes-1 和 Hey-1 的表达,这些转录因子与分化丧失有关。本研究旨在探讨 BMP-2 诱导β细胞功能障碍和细胞成熟丧失的机制。将小鼠胰岛暴露于 BMP-2 10 天会导致葡萄糖刺激的胰岛素分泌受损和β细胞增殖减少。BMP-2 诱导的β细胞功能障碍与β细胞特有的细胞成熟和增殖标志物的表达减少有关,如 Ins1、Ucn3 和 Ki67,以及 Id1-4、Hes-1 和 Hey-1 的表达增加。前 30 个受调控最多的蛋白与相应的 mRNA 表达显著相关。BMP-2 诱导的基因表达变化与 H3K27 乙酰化的主要减少和 NeuroD1 染色质结合活性的降低有关。这些结果表明 BMP-2 诱导β细胞成熟丧失,并表明 H3K27ac 的重塑和 NeuroD1 DNA 结合活性的降低参与了 BMP-2 对β细胞功能障碍的影响。