Hu Bo, Tong Fei, Xu Long, Shen Zhiwei, Yan Lijian, Xu Guangtao, Shen Ruilin
Kidney Blood Press Res. 2018;43(1):276-286. doi: 10.1159/000487685. Epub 2018 Feb 22.
BACKGROUND/AIMS: Renal ischemia/reperfusion (I/R) injury (RI/RI) is a common complication of diabetes, and it may be involved in altering intracellular calcium concentrations at its onset, which can result in inflammation, abnormal lipid metabolism, the production of reactive oxygen species (ROS), and nitroso-redox imbalance. The calcium-sensing receptor (CaSR) is a G-protein coupled receptor, however, the functional involvement of CaSR in diabetic RI/ RI remains unclear. The present study was intended to investigate the role of CaSR on RI/RI in diabetes mellitus (DM).
The bilateral renal arteries and veins of streptozotocin (STZ)-induced diabetic rats were subjected to 45-min ischemia followed by 2-h reperfusion with or without R-568 (agonist of CaSR) and NPS-2143 (antagonist of CaSR) at the beginning of I/R procedure. DM without renal I/R rats served as control group. The expressions of CaSR, calmodulin (CaM), and p47phox in the renal tissue were analyzed by qRT-PCR and Western blot. The renal pathomorphology, renal function, oxidative stress, inflammatory response, and calcium disorder were evaluated by detection of a series of indices by hematoxylin-eosin (HE) staining, transmission electron microscope (TEM), commercial kits, enzyme-linked immunosorbent assay (ELISA), and spectrophotofluorometry, respectively.
Results showed that the expressions of CaSR, CaM, and p47phox in I/R group were significantly up-regulated as compared with those in DM group, which were accompanied by renal tissue injury, increased calcium, oxidative stress, inflammation, and nitroso-redox imbalance.
These results suggest that activation of CaSR is involved in the induction of damage of renal tubular epithelial cell during diabetic RI/RI, resulting in lipid peroxidation, inflammatory response, nitroso-redox imbalance, and apoptosis.
背景/目的：肾缺血/再灌注（I/R）损伤是糖尿病的常见并发症，其发病初期可能涉及细胞内钙浓度的改变，进而导致炎症、脂质代谢异常、活性氧（ROS）生成及亚硝基-氧化还原失衡。钙敏感受体（CaSR）是一种G蛋白偶联受体，然而，CaSR在糖尿病性肾I/R损伤中的功能作用尚不清楚。本研究旨在探讨CaSR在糖尿病（DM）肾I/R损伤中的作用。
对链脲佐菌素（STZ）诱导的糖尿病大鼠双侧肾动静脉进行45分钟缺血，然后在I/R过程开始时，分别给予或不给予R-568（CaSR激动剂）和NPS-2143（CaSR拮抗剂）进行2小时再灌注。无肾I/R的糖尿病大鼠作为对照组。通过qRT-PCR和蛋白质免疫印迹法分析肾组织中CaSR、钙调蛋白（CaM）和p47phox的表达。分别通过苏木精-伊红（HE）染色、透射电子显微镜（TEM）、商用试剂盒、酶联免疫吸附测定（ELISA）和分光光度荧光法检测一系列指标，评估肾脏病理形态学、肾功能、氧化应激、炎症反应和钙紊乱情况。
结果显示，与糖尿病组相比，I/R组中CaSR、CaM和p47phox的表达显著上调，同时伴有肾组织损伤、钙增加、氧化应激、炎症和亚硝基-氧化还原失衡。
这些结果表明，CaSR的激活参与糖尿病性肾I/R损伤期间肾小管上皮细胞损伤的诱导，导致脂质过氧化、炎症反应、亚硝基-氧化还原失衡和细胞凋亡。
