Department of Anesthesiology, Affiliated Hospital of Chengde Medical College, Chengde, China.
Department of Orthopedics, Affiliated Hospital of Chengde Medical College, Chengde, China.
Nephron. 2021;145(5):528-539. doi: 10.1159/000514532. Epub 2021 May 7.
Ischemia-reperfusion (I/R) injury is the main cause of acute kidney injury (AKI), and its incidence and mortality increase year by year in the population. Dexmedetomidine (DEX) can improve AKI by regulating inflammation and oxidative stress, but its mechanism is still unclear.
A hypoxia/reoxygenation (H/R) model of HK-2 cells and a kidney I/R model of C57BL/6J mice were established. In the experiment, cells were transfected with sh-PGC-1α to inhibit PGC-1α expression. The changes of ROS level and mitochondrial membrane potential (MMP) were analyzed. HE staining was used to assess kidney damage in mice. Concentration of kidney injury markers serum creatinine and blood urea nitrogen and expression of inflammatory factors were detected by ELISA. qPCR analysis was used to detect mRNA levels of related proteins in cells and mouse kidney tissues. The protein intracellular content and phosphorylation levels were determined by Western blotting.
The production of inflammatory factors and ROS was increased in HK-2 cells treated with H/R, while MMP, cell viability, and mitochondrial-related protein levels were decreased. DEX attenuated pathological changes induced by H/R, while knockdown of PGC-1α eliminated the mitigation effect. DEX inhibited the damage of I/R to the kidneys of mice and increased the expression of mitochondrial-related proteins and PGC-1α in the kidneys, while inhibiting the phosphorylation of STAT1 and the expression of IRF-1.
DEX appears to inhibit mitochondrial damage and cellular inflammation by upregulating PGC-1α to affect STAT1 phosphorylation level and IRF-1 expression, thereby preventing AKI.
缺血再灌注(I/R)损伤是急性肾损伤(AKI)的主要原因,其在人群中的发病率和死亡率逐年增加。右美托咪定(DEX)可以通过调节炎症和氧化应激来改善 AKI,但具体机制尚不清楚。
建立 HK-2 细胞缺氧/复氧(H/R)模型和 C57BL/6J 小鼠肾脏 I/R 模型。实验中转染 sh-PGC-1α 抑制 PGC-1α 表达。分析 ROS 水平和线粒体膜电位(MMP)的变化。HE 染色评估小鼠肾脏损伤。通过 ELISA 检测血清肌酐和血尿素氮等肾损伤标志物的浓度,以及炎性因子的表达。qPCR 分析细胞和小鼠肾组织中相关蛋白的 mRNA 水平。通过 Western blot 测定细胞内蛋白含量和磷酸化水平。
H/R 处理的 HK-2 细胞中炎性因子和 ROS 的产生增加,而 MMP、细胞活力和线粒体相关蛋白水平降低。DEX 减轻了 H/R 引起的病理变化,而敲低 PGC-1α 则消除了这种缓解作用。DEX 抑制了 I/R 对小鼠肾脏的损伤,增加了肾脏中线粒体相关蛋白和 PGC-1α 的表达,同时抑制了 STAT1 的磷酸化和 IRF-1 的表达。
DEX 似乎通过上调 PGC-1α 来抑制线粒体损伤和细胞炎症,从而影响 STAT1 磷酸化水平和 IRF-1 的表达,从而预防 AKI。