高尿酸血症（HUA）已成为肾小管损伤的常见病因，但分子机制不清。课题组前期发现，自发HUA小鼠肾脏出现尿酸钠（MSU）晶体沉积，肾小管坏死，ROS生成增多，RIPK1磷酸化水平上调；ROS清除剂能够显著抑制MSU引起的RIPK1磷酸化及肾小管上皮细胞损伤。推测MSU通过诱导ROS生成，调控RIPK1信号通路，导致肾小管损伤。本课题拟：⑴在HK-2细胞和原代肾小管上皮细胞检测MSU对ROS主要生成途径线粒体功能与Nox4表达水平的影响，并应用ROS诱导剂或清除剂、RIPK1信号通路及ROS生成关键分子抑制剂和RNAi干预，明确MSU诱导生成的ROS对RIPK1信号通路及肾小管上皮细胞损伤的影响；⑵应用RIPK1条件性基因敲除自发HUA小鼠，在动物水平验证ROS对RIPK1信号通路的激活在MSU诱导肾小管损伤中的作用。本研究将明确MSU引起肾小管损伤的分子机制，为尿酸性肾病的早期防治提供依据。

Although hyperuricemia (HUA) and gout have been identified as common etiological factor renal tubular injury, the molecular mechanisms underlying renal tubular impairments caused by HUA remain evasive. Our previous study showed monosodium urate (MSU) crystal deposition, ROS production increased and renal tubular necrosis in spontaneous HUA mouse model. Further study showed that RIPK1/RIPK3/MLKL expression levels and phosphorylation levels were up-regulated, and the enhanced phosphorylation level of RIPK1 could be inhibited by ROS scavenger. Therefore, we speculated that MSU may up-regulate the phosphorylation level of RIPK1 via inducing the production of ROS , and ultimately lead to renal tubular injury. In the present study, we plan to (1) examine the effects of MSU on mitochondrial function and Nox4 expression level, two main pathway of ROS production, and the effects of ROS on RIPK1 signaling pathway and cell damage in HK-2 cells and primary renal tubular epithelial cells, after intervention with ROS modulators NAC or BSO, key molecule-specific inhibitors of the RIPK1 signaling pathway and RNAi. (2) verify the role of RIPK1 signaling pathway actived by ROS in MSU-induced tubular injury at the animal level in RIPK1 conditional gene knockout spontaneous HUA mice. By unraveling the molecular mechanism of MSU-regulated renal tubular injury through oxidative stress, this study will provide scientific basis for early treatment and prevention of MSU-induced urate nephropathy.