Acad Integrated Med & College of Pharmacy, Department of Pharmacology, Dalian Medical University, 9 Western Section, Lvshun South Street, Dalian, 116044, China.
Department of Jilin University, Changchun, China.
Cell Biol Toxicol. 2022 Jun;38(3):531-551. doi: 10.1007/s10565-021-09644-7. Epub 2021 Aug 28.
Diabetes mellitus (DM) is a metabolic syndrome, caused by insufficient insulin secretion or insulin resistance (IR). DM enhances oxidative stress and induces mitochondrial function in different kinds of cell types, including pancreatic β-cells. Our previous study has showed phosphocreatine (PCr) can advance the mitochondrial function through enhancing the oxidative phosphorylation and electron transport ability in mitochondria damaged by methylglyoxal (MG). Our aim was to explore the potential role of PCr as a molecule to protect mitochondria from diabetes-induced pancreatic β-cell injury with insulin secretion deficiency or IR through dual AKT/IRS-1/GSK-3β and STAT3/Cyclophilin D (Cyp-D) signaling pathways. MG-induced INS-1 cell viability, apoptosis, mitochondrial division and fusion, the morphology, and function of mitochondria were suppressed. Flow cytometry was used to detect the production of intracellular reactive oxygen species (ROS) and the changes of intracellular calcium, and the respiratory function was measured by oxygraph-2k. The expressions of AKT, IRS-1, GSK-3β, STAT3, and Cyp-D were detected using Western blot. The result showed that the oxidative stress-related kinases were significantly restored to the normal level after the pretreatment with PCr. Moreover, PCr pretreatment significantly inhibited cell apoptosis, decreased intracellular calcium, and ROS production, and inhibited mitochondrial division and fusion, and increased ATP synthesis damaged by MG in INS-1 cells. In addition, pretreatment with PCr suppressed Cytochrome C, p-STAT3, and Cyp-D expressions, while increased p-AKT, p-IRS-1, p-GSK-3β, caspase-3, and caspase-9 expressions. In conclusion, PCr has protective effect on INS-1 cells in vitro and in vivo, relying on AKT mediated STAT3/ Cyp-D pathway to inhibit oxidative stress and restore mitochondrial function, signifying that PCr might become an emerging candidate for the cure of diabetic pancreatic cancer β-cell damage.
糖尿病（DM）是一种代谢综合征，由胰岛素分泌不足或胰岛素抵抗（IR）引起。DM 会增强氧化应激，并诱导包括胰岛β细胞在内的不同类型细胞中线粒体功能障碍。我们之前的研究表明，磷酸肌酸（PCr）可以通过增强受损线粒体的氧化磷酸化和电子传递能力来提高线粒体功能，这些线粒体是由甲基乙二醛（MG）损伤的。我们的目的是通过双重 AKT/IRS-1/GSK-3β 和 STAT3/Cyclophilin D（Cyp-D）信号通路，探索 PCr 作为一种分子的潜在作用，以保护线粒体免受糖尿病诱导的胰岛β细胞损伤，表现为胰岛素分泌不足或 IR。MG 诱导的 INS-1 细胞活力、凋亡、线粒体分裂和融合、线粒体形态和功能均受到抑制。流式细胞术用于检测细胞内活性氧（ROS）的产生和细胞内钙离子的变化，通过 oxygraph-2k 测量呼吸功能。Western blot 检测 AKT、IRS-1、GSK-3β、STAT3 和 Cyp-D 的表达。结果表明，PCr 预处理后，与氧化应激相关的激酶明显恢复到正常水平。此外，PCr 预处理可显著抑制细胞凋亡，减少细胞内钙离子和 ROS 的产生，抑制 MG 诱导的 INS-1 细胞线粒体分裂和融合，并增加 ATP 合成。此外，PCr 预处理抑制 Cytochrome C、p-STAT3 和 Cyp-D 的表达，而增加 p-AKT、p-IRS-1、p-GSK-3β、caspase-3 和 caspase-9 的表达。综上所述，PCr 对体外和体内的 INS-1 细胞具有保护作用，通过 AKT 介导的 STAT3/Cyp-D 通路抑制氧化应激并恢复线粒体功能，表明 PCr 可能成为治疗糖尿病胰岛β细胞损伤的一种新的候选药物。
