Gong Maolian, Yu Yong, Liang Lei, Vuralli Dogus, Froehler Sebastian, Kuehnen Peter, Du Bois Philipp, Zhang Jingjing, Cao Aidi, Liu Yuantao, Hussain Khalid, Fielitz Jens, Jia Shiqi, Chen Wei, Raile Klemens
Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty, Max-Delbrueck-Center for Molecular Medicine (MDC), Berlin, Germany.
Qingdao Municipal Hospital, Qingdao, China.
Mol Genet Genomic Med. 2019 May;7(5):e602. doi: 10.1002/mgg3.602. Epub 2019 Apr 9.
Studying patients with rare Mendelian diabetes has uncovered molecular mechanisms regulating β-cell pathophysiology. Previous studies have shown that Class IIa histone deacetylases (HDAC4, 5, 7, and 9) modulate mammalian pancreatic endocrine cell function and glucose homeostasis.
We performed exome sequencing in one adolescent nonautoimmune diabetic patient and detected one de novo predicted disease-causing HDAC4 variant (p.His227Arg). We screened our pediatric diabetes cohort with unknown etiology using Sanger sequencing. In mouse pancreatic β-cell lines (Min6 and SJ cells), we performed insulin secretion assay and quantitative RT-PCR to measure the β-cell function transfected with the detected HDAC4 variants and wild type. We carried out immunostaining and Western blot to investigate if the detected HDAC4 variants affect the cellular translocation and acetylation status of Forkhead box protein O1 (FoxO1) in the pancreatic β-cells.
We discovered three HDAC4 mutations (p.His227Arg, p.Asp234Asn, and p.Glu374Lys) in unrelated individuals who had nonautoimmune diabetes with various degrees of β-cell loss. In mouse pancreatic β-cell lines, we found that these three HDAC4 mutations decrease insulin secretion, down-regulate β-cell-specific transcriptional factors, and cause nuclear exclusion of acetylated FoxO1.
Mutations in HDAC4 disrupt the deacetylation of FoxO1, subsequently decrease the β-cell function including insulin secretion, resulting in diabetes.
对患有罕见孟德尔糖尿病的患者进行研究，揭示了调节β细胞病理生理学的分子机制。先前的研究表明，IIa类组蛋白去乙酰化酶（HDAC4、5、7和9）可调节哺乳动物胰腺内分泌细胞功能和葡萄糖稳态。
我们对一名青少年非自身免疫性糖尿病患者进行了外显子组测序，检测到一个新的预测致病HDAC4变异（p.His227Arg）。我们使用桑格测序法对病因不明的儿科糖尿病队列进行了筛查。在小鼠胰腺β细胞系（Min6和SJ细胞）中，我们进行了胰岛素分泌测定和定量逆转录聚合酶链反应，以测量转染了检测到的HDAC4变异和野生型的β细胞功能。我们进行了免疫染色和蛋白质免疫印迹，以研究检测到的HDAC4变异是否影响胰腺β细胞中叉头框蛋白O1（FoxO1）的细胞易位和乙酰化状态。
我们在患有不同程度β细胞丢失的非自身免疫性糖尿病的无关个体中发现了三个HDAC4突变（p.His227Arg、p.Asp234Asn和p.Glu374Lys）。在小鼠胰腺β细胞系中，我们发现这三个HDAC4突变会降低胰岛素分泌，下调β细胞特异性转录因子，并导致乙酰化FoxO1的核排除。
HDAC4突变破坏了FoxO1的去乙酰化，随后降低了包括胰岛素分泌在内的β细胞功能，导致糖尿病。
