Department of Nephrology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China.
Department of Nephrology, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Traditional Chinese Medicine Institute of Kidney Disease of Shanghai University of Traditional Chinese Medicine, Key Laboratory of Liver and Kidney Diseases, Ministry of Education, Shanghai Key Laboratory of Traditional Chinese Clinical Medicine, Shanghai 200011, China.
J Biol Chem. 2019 Nov 8;294(45):16908-16917. doi: 10.1074/jbc.RA119.011009. Epub 2019 Oct 2.
The role of RNA methylation on the sixth N atom of adenylate (mA) in acute kidney injury (AKI) is unknown. FTO (fat mass and obesity-associated protein) reverses the mA modification in cisplatin-induced AKI. Here, we aimed to determine FTO's role in AKI. We induced AKI in c57BL/6 mice by intraperitoneal cisplatin injection and treated the animal with vehicle or an FTO inhibitor meclofenamic acid (MA) for 3 days. Moreover, as an model, human kidney proximal tubular cells (HK2 cells) were treated with cisplatin. We found that the cisplatin treatment reduces FTO expression and increases mA levels and MA aggravated renal damage and increased apoptosis in cisplatin-treated kidneys, phenotypes that were correlated with reduced FTO expression and increased mA levels. Moreover, MA promoted apoptosis in cisplatin-treated HK2 cells, which was correlated with the reduced FTO expression and increased mA in HK2 cells. FTO protein overexpression reduced mA levels and inhibited apoptosis in cisplatin-treated HK2 cells and also blocked the MA-induced increase in mA levels and apoptosis rates. In agreement, overexpression of the mA-generating methyltransferase-like 3 and 14 (METTL3 and METTL14) or siRNA-mediated FTO knockdown promoted apoptosis and enhanced mA levels in cisplatin-treated HK2 cells. MA increased p53 mRNA and protein levels in AKI both and , and FTO overexpression reduced p53 expression and reversed the MA-induced p53 increase in AKI. In conclusion, reduced renal FTO expression in cisplatin-induced AKI increases RNA mA levels and aggravates renal damages.
腺苷酸第 6 位 N 原子上的 RNA 甲基化(mA)在急性肾损伤(AKI)中的作用尚不清楚。FTO(肥胖相关蛋白)可逆转顺铂诱导的 AKI 中的 mA 修饰。在这里,我们旨在确定 FTO 在 AKI 中的作用。我们通过腹腔内注射顺铂诱导 c57BL/6 小鼠发生 AKI,并在 3 天内用载体或 FTO 抑制剂甲氯芬酸(MA)对动物进行治疗。此外,作为一种 模型,用顺铂处理人肾近端小管细胞(HK2 细胞)。我们发现顺铂处理降低了 FTO 的表达并增加了 mA 水平,并且 MA 加重了顺铂处理肾脏的损伤并增加了细胞凋亡,这些表型与 FTO 表达降低和 mA 水平升高相关。此外,MA 促进了顺铂处理的 HK2 细胞中的细胞凋亡,这与 HK2 细胞中 FTO 表达降低和 mA 水平升高有关。FTO 蛋白过表达降低了 mA 水平并抑制了顺铂处理的 HK2 细胞中的细胞凋亡,并且阻断了 MA 诱导的 mA 水平和凋亡率的增加。一致地,过表达 mA 生成甲基转移酶样 3 和 14(METTL3 和 METTL14)或 siRNA 介导的 FTO 敲低促进了顺铂处理的 HK2 细胞中的细胞凋亡并增强了 mA 水平。MA 增加了 AKI 中 p53 mRNA 和蛋白质水平,并且 FTO 过表达降低了 p53 表达并逆转了 MA 诱导的 AKI 中 p53 的增加。总之,顺铂诱导的 AKI 中肾脏 FTO 表达降低会增加 RNA mA 水平并加重肾脏损伤。