Zhang Xiaobo, Zhu Ying, Zhou Ying, Fei Bingru
Nephrology Department, The Affiliated Huaian No. 1 People's Hospital of Nanjing Medical University, Huaian, Jiangsu Province 223300, People's Republic of China.
Diabetes Metab Syndr Obes. 2020 Jun 23;13:2169-2177. doi: 10.2147/DMSO.S246743. eCollection 2020.
Renal ischemia/reperfusion (I/R) injury is commonly seen in diabetic patients. Apelin has been demonstrated to protect against renal I/R injury, whereas detailed modulatory mechanisms by which Apelin exerts its role in renal I/R injury in diabetic patients remain unclarified. This research aimed to probe the functional molecules under the regulation of Apelin in renal I/R injury in diabetic rats.
First, animal models were established for subsequent assays. Biochemical kits measured the serum levels of blood urea nitrogen (BUN) and serum creatinine (SCR), and hematoxylin and eosin (H&E) staining examined the histopathological changes of kidney tissues. Inflammatory factors containing tumor necrosis factor alpha (TNF-α), interleukin 1β (IL-1β), interleukin 6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) were tested through enzyme-linked immunosorbent assay (ELISA) and reverse transcription-quantitative polymerase chain reaction (RT-qPCR), respectively. Reactive oxygen species (ROS) levels in the serum and kidney tissues were separately assessed by specific ROS kits. Cell apoptosis was further estimated through terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and Western blot analysis. Eventually, the influences of Apelin on nuclear factor erythroid 2-related factor (Nrf2) and its downstream genes were explored via Western blot analysis and immunohistochemistry (IHC).
In the present study, Apelin ameliorated the damage to renal function and histological structure, decreased levels of inflammatory factors and ROS, and hampered cell apoptosis in renal I/R injury of diabetic rats. Moreover, Apelin could elevate the levels of Nrf2 and downstream genes which were decreased under renal I/R injury.
These data indicated that Apelin inhibited renal I/R injury through regulating Nrf2 signaling in diabetic rats, which might shed new light on the treatment of renal I/R injury in diabetic patients.
肾缺血/再灌注（I/R）损伤在糖尿病患者中很常见。已证实Apelin可预防肾I/R损伤，然而，Apelin在糖尿病患者肾I/R损伤中发挥作用的具体调节机制仍不清楚。本研究旨在探讨Apelin在糖尿病大鼠肾I/R损伤中调控的功能分子。
首先，建立动物模型用于后续实验。生化试剂盒检测血清尿素氮（BUN）和血清肌酐（SCR）水平，苏木精-伊红（H&E）染色检查肾组织的组织病理学变化。分别通过酶联免疫吸附测定（ELISA）和逆转录-定量聚合酶链反应（RT-qPCR）检测包含肿瘤坏死因子α（TNF-α）、白细胞介素1β（IL-1β）、白细胞介素6（IL-6）和单核细胞趋化蛋白-1（MCP-1）的炎症因子。通过特定的活性氧（ROS）试剂盒分别评估血清和肾组织中的ROS水平。通过末端脱氧核苷酸转移酶介导的dUTP缺口末端标记（TUNEL）和蛋白质免疫印迹分析进一步评估细胞凋亡。最终，通过蛋白质免疫印迹分析和免疫组织化学（IHC）探讨Apelin对核因子红细胞2相关因子（Nrf2）及其下游基因的影响。
在本研究中，Apelin改善了糖尿病大鼠肾I/R损伤中肾功能和组织结构的损伤，降低了炎症因子和ROS水平，并抑制了细胞凋亡。此外，Apelin可提高在肾I/R损伤时降低的Nrf2及其下游基因的水平。
这些数据表明，Apelin通过调节糖尿病大鼠的Nrf2信号通路抑制肾I/R损伤，这可能为糖尿病患者肾I/R损伤的治疗提供新的思路。
