Second Department of Cardiovascular Medicine, The First People's Hospital of Shangqiu City, Shangqiu, China.
Bioengineered. 2022 Mar;13(3):7697-7708. doi: 10.1080/21655979.2022.2034706.
Myocardial ischemia-reperfusion injury in diabetic patients leads to an increased incidence of complications and mortality. Secreted frizzled-related protein 4 (SFRP4) plays a critical role in diabetic myocardial ischemia-reperfusion. This paper aims to uncover the underlying mechanisms of SFRP4 in hypoxia/reoxygenation (H/R) injury of diabetic myocardial cells. An in vitro ischemia/reperfusion (I/R) injury model was established using high glucose-induced H9c2 cardiomyocytes. Expression of SFRP4 was detected by real-time reverse transcriptase-polymerase chain reaction and Western blotting. After transfection of SFRP4, the binding of SFRP4 to protein tyrosine phosphatase nonreceptor type 12 (PTPN12) was predicted by database and verified by co-immunoprecipitation assay. P13 K/AKT protein levels were examined by Western blotting. PTPN12 levels were tested by RT-qPCR and Western blotting, cell viability by Cell Counting Kit-8, lactose dehydrogenase kit, terminal dUTP nick-end labeling assay, and cell inflammation and oxidative stress by Western blotting and enzyme linked immunosorbent assay. After overexpression of PTPN12, the experiments for cell viability, inflammation and oxidative stress were repeated once more. SFRP4 expression was upregulated in a high-glucose-stimulated H/R cardiomyocyte model. The interference of SFRP4 promoted cell viability, inhibited the inflammatory and oxidative stress response of H/R cardiomyocytes induced by high glucose. SFRP4 interacted with PTPN12 and inhibited the PI3K/AKT signaling pathway. PTPN12 overexpression reversed the inhibitory effect of sh-SFRP4 on H/R cardiomyocyte damage induced by high glucose. Downregulation of SFRP4 inhibited H/R cell damage in diabetic cardiomyocytes by binding to PTPN12.
糖尿病患者的心肌缺血再灌注损伤导致并发症和死亡率增加。分泌卷曲相关蛋白 4（SFRP4）在糖尿病性心肌缺血再灌注中起着关键作用。本文旨在揭示 SFRP4 在高糖诱导的 H9c2 心肌细胞缺氧/复氧（H/R）损伤中的潜在机制。通过高糖诱导的 H9c2 心肌细胞建立体外缺血/再灌注（I/R）损伤模型。通过实时逆转录-聚合酶链反应和 Western blot 检测 SFRP4 的表达。转染 SFRP4 后，通过数据库预测 SFRP4 与蛋白酪氨酸磷酸酶非受体型 12（PTPN12）的结合，并通过共免疫沉淀实验验证。通过 Western blot 检测 P13K/AKT 蛋白水平。通过 RT-qPCR 和 Western blot 检测 PTPN12 水平，通过细胞计数试剂盒-8、乳酸脱氢酶试剂盒、末端脱氧核苷酸转移酶介导的缺口末端标记测定法检测细胞活力，通过 Western blot 和酶联免疫吸附测定法检测细胞炎症和氧化应激。过表达 PTPN12 后，再次重复细胞活力、炎症和氧化应激的实验。在高糖刺激的 H/R 心肌细胞模型中 SFRP4 表达上调。SFRP4 的干扰促进了细胞活力，抑制了高糖诱导的 H/R 心肌细胞的炎症和氧化应激反应。SFRP4 与 PTPN12 相互作用并抑制 PI3K/AKT 信号通路。过表达 PTPN12 逆转了 sh-SFRP4 对高糖诱导的 H/R 心肌细胞损伤的抑制作用。下调 SFRP4 通过与 PTPN12 结合抑制糖尿病心肌细胞的 H/R 细胞损伤。
