Imeglimin Ameliorates β-cell Apoptosis by Modulating the Endoplasmic Reticulum Homeostasis Pathway
figureposted on 29.09.2021, 15:40 by Jinghe Li, Ryota Inoue, Yu Togashi, Tomoko Okuyama, Aoi Satoh, Mayu Kyohara, Kuniyuki Nishiyama, Takahiro Tsuno, Daisuke Miyashita, Tatsuya Kin, A.M. James Shapiro, Resilind Su Ern Chew, Adrian Kee Keong Teo, Seiichi Oyadomari, Yasuo Terauchi, Jun Shirakawa
The effects of imeglimin, a novel anti-diabetes agent, on β-cell function remain unclear. Here, we unveiled the impact of imeglimin on β-cell survival. Treatment with imeglimin augmented mitochondrial function, enhanced insulin secretion, promoted β-cell proliferation, and improved β-cell survival in mouse islets. Imeglimin upregulated the expression of endoplasmic reticulum (ER)-related molecules including Chop (Ddit3), Gadd34 (Ppp1r15a), Atf3, and Sdf2l1, and decreased eIF2α phosphorylation, after treatment with thapsigargin, and restored global protein synthesis in β-cells under ER stress. Imeglimin failed to protect ER stress-induced β-cell apoptosis in CHOP-deficient islets or in the presence of GADD34 inhibitor. Treatment with imeglimin showed a significant decrease in the number of apoptotic β-cells and increased β-cell mass in Akita mice. Imeglimin also protected against β-cell apoptosis in both human islets and human pluripotent stem cell (hPSC)-derived β-like cells. Taken together, imeglimin modulates ER homeostasis pathway, which results in the prevention of β-cell apoptosis both in vitro and in vivo.