Xie Xiang-Cheng, Zhao Ning, Xu Qun-Hong, Yang Xiu, Xia Wen-Kai, Chen Qi, Wang Ming, Fei Xiao
Department of Nephrology, Hangzhou First People's Hospital, Nanjing Medical University, No. 261, Huansha Road, Hangzhou, 310006, Zhejiang, China.
Department of Nephrology, Jiangyin People's Hospital, No. 163, Shoushan Road, Jiangyin, 214400, Jiangsu, China.
Apoptosis. 2017 Jun;22(6):769-776. doi: 10.1007/s10495-017-1369-z.
Aristolochic acid nephropathy remains a leading cause of chronic kidney disease (CKD), however few treatment strategies exist. Emerging evidence has shown that H2 relaxin (RLX) possesses powerful antifibrosis and anti-apoptotic properties, therefore we aimed to investigate whether H2 relaxin can be employed to reduce AA-induced cell apoptosis. Human proximal tubular epithelial (HK-2) cells exposed to AA-I were treated with or without administration of H2 RLX. Cell viability was examined using the WST-8 assay. Apoptotic morphologic alterations were observed using the Hoechst 33342 staining method. Apoptosis was detected using flow cytometry. The expression of caspase 3, caspase 8, caspase 9, ERK1/2, Bax, Bcl-2, and Akt proteins was determined by Western blot. Co-treatment with RLX reversed the increased apoptosis observed in the AA-I only treated group. RLX restored expression of phosphorylated Akt which found to be decreased in the AA-I only treated cells. RLX co-treatment led to a decrease in the Bax/Bcl-2 ratio as well as the cleaved form of caspase-3 compared to the AA-I only treated cells. This anti-apoptotic effect of RLX was attenuated by co-administration of the Akt inhibitor LY294002. The present study demonstrated H2 RLX can decrease AA-I induced apoptosis through activation of the PI3K/Akt signaling pathway.
马兜铃酸肾病仍然是慢性肾脏病（CKD）的主要病因，然而治疗策略却很少。新出现的证据表明，H2松弛素（RLX）具有强大的抗纤维化和抗凋亡特性，因此我们旨在研究H2松弛素是否可用于减少马兜铃酸诱导的细胞凋亡。将暴露于马兜铃酸I（AA-I）的人近端肾小管上皮（HK-2）细胞分为给予或不给予H2 RLX进行处理。使用WST-8法检测细胞活力。采用Hoechst 33342染色法观察凋亡形态学改变。通过流式细胞术检测细胞凋亡。采用蛋白质印迹法测定半胱天冬酶3、半胱天冬酶8、半胱天冬酶9、细胞外信号调节激酶1/2、Bax、Bcl-2和Akt蛋白的表达。与仅用AA-I处理的组相比，RLX联合处理可逆转观察到的细胞凋亡增加。RLX恢复了磷酸化Akt的表达，而在仅用AA-I处理的细胞中磷酸化Akt的表达降低。与仅用AA-I处理的细胞相比，RLX联合处理导致Bax/Bcl-2比值以及半胱天冬酶-3的裂解形式降低。Akt抑制剂LY294002联合给药减弱了RLX的这种抗凋亡作用。本研究表明，H2 RLX可通过激活PI3K/Akt信号通路减少AA-I诱导的细胞凋亡。
