Department of Nephrology, Minda Hospital Affiliated to Hubei Minzu University, Hubei Clinical Research Center for Kidney Disease, Enshi, PR China.
Department of Endocrinology, The Third People's Hospital of Datong, Datong, PR China.
Nutr Cancer. 2023;75(6):1464-1472. doi: 10.1080/01635581.2023.2203353. Epub 2023 May 4.
TP53-induced glycolysis and apoptosis regulator (TIGAR) acts as a switch for nephropathy, but its underlying mechanism is still unclear. The purpose of this study was to explore the potential biological significance and underlying mechanism of TIGAR in modulating adenine-induced ferroptosis in human proximal tubular epithelial (HK-2) cells. HK-2 cells under- or overexpressing TIGAR were challenged with adenine to induce ferroptosis. The levels of reactive oxygen species (ROS), iron, malondialdehyde (MDA), and glutathione (GSH) were assayed. Expression of ferroptosis-associated solute carrier family seven-member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) at the level of mRNA and protein were measured by quantitative real-time-PCR and western blotting. The phosphorylation levels of proteins in the mTOR/S6KP70 pathway were determined by western blotting. Adenine overload triggered ferroptosis in HK-2 cells, as evidenced by reduced levels of GSH, SLC7A11, and GPX4, and increased levels of iron, MDA, and ROS. TIGAR overexpression repressed adenine-induced ferroptosis and induced mTOR/S6KP70 signaling. Inhibitors of mTOR and S6KP70 weakened the ability of TIGAR to inhibit adenine-induced ferroptosis. TIGAR inhibits adenine-induced ferroptosis in human proximal tubular epithelial cells by activating the mTOR/S6KP70 signaling pathway. Therefore, activating the TIGAR/mTOR/S6KP70 axis may be a treatment for crystal nephropathies.
TP53 诱导的糖酵解和凋亡调节剂（TIGAR）在肾病中起作用，但它的潜在机制尚不清楚。本研究旨在探讨 TIGAR 调节人近端肾小管上皮（HK-2）细胞腺嘌呤诱导的铁死亡的潜在生物学意义和机制。用腺嘌呤处理 TIGAR 低表达或过表达的 HK-2 细胞，以诱导铁死亡。测定活性氧（ROS）、铁、丙二醛（MDA）和谷胱甘肽（GSH）的水平。通过定量实时-PCR 和 Western blot 测定铁死亡相关溶质载体家族 7 成员 11（SLC7A11）和谷胱甘肽过氧化物酶 4（GPX4）在 mRNA 和蛋白水平的表达。Western blot 测定 mTOR/S6KP70 通路中蛋白的磷酸化水平。腺嘌呤过载导致 HK-2 细胞发生铁死亡，表现为 GSH、SLC7A11 和 GPX4 水平降低，铁、MDA 和 ROS 水平升高。TIGAR 过表达抑制腺嘌呤诱导的铁死亡，并诱导 mTOR/S6KP70 信号。mTOR 和 S6KP70 的抑制剂削弱了 TIGAR 抑制腺嘌呤诱导的铁死亡的能力。TIGAR 通过激活 mTOR/S6KP70 信号通路抑制人近端肾小管上皮细胞中的腺嘌呤诱导的铁死亡。因此，激活 TIGAR/mTOR/S6KP70 轴可能是治疗晶体肾病的一种方法。
