Article
作者: Zheng, Min ; Wang, Ruo-Ran ; Wu, Qing-Qian ; Yan, Jing ; Wang, Wen ; Luo, Ping ; Zhang, Rong ; Zhang, Wenjing ; Wang, Qintao ; Yan, Sheng ; Zhu, Lingyun ; Ji, Xiuyu ; Ding, Wei ; Chen, Haide ; Zhang, Ziyin ; Piao, Hai-Long ; Yan, Dandan ; Pan, Xiaowen ; Zhu, Shuaishuai ; Liang, Bin ; Li, Chengbin ; Jin, Li ; Shi, Mengjie ; Qiu, Xinyuan ; Chen, Wei ; Guo, Guoji ; Hu, Cheng ; Fu, Hongxing ; Meng, Zhuo-Xian ; Yang, Yingqing
Impaired glucose-stimulated insulin secretion (GSIS) is a hallmark of β cell dysfunction in diabetes. Epigenetic mechanisms govern cellular glucose sensing and GSIS by β cells, but they remain incompletely defined. Here, we found that BAF60a functions as a chromatin regulator that sustains biphasic GSIS and preserves β cell function under metabolic stress conditions. BAF60a was downregulated in β cells from obese and diabetic mice, monkeys, and humans. β cell-specific inactivation of BAF60a in adult mice impaired GSIS, leading to hyperglycemia and glucose intolerance. Conversely, restoring BAF60a expression improved β cell function and systemic glucose homeostasis. Mechanistically, BAF60a physically interacted with Nkx6.1 to selectively modulate chromatin accessibility and transcriptional activity of target genes critical for GSIS coupling in islet β cells. A BAF60a V278M mutation associated with decreased β cell GSIS function was identified in human donors. Mice carrying this mutation, which disrupted the interaction between BAF60a and Nkx6.1, displayed β cell dysfunction and impaired glucose homeostasis. In addition, GLP-1R and GIPR expression was significantly reduced in BAF60a-deficient islets, attenuating the insulinotropic effect of GLP-1R agonists. Together, these findings support a role for BAF60a as a component of the epigenetic machinery that shapes the chromatin landscape in β cells critical for glucose sensing and insulin secretion.