Sun Yushi, Li Bojun, Song Baofeng, Xia Yuqi, Ye Zehua, Lin Fangyou, Zhou Xiangjun, Li Wei, Rao Ting, Cheng Fan
Department of Urology, Renmin Hospital of Wuhan University, No.238 Jiefang Road, Wuchang District, Wuhan, Hubei, 430060, People's Republic of China.
Department of Anesthesiology, Renmin Hospital of Wuhan University, Wuhan, 430060, China.
Cell Biol Toxicol. 2025 Feb 3;41(1):39. doi: 10.1007/s10565-025-09991-9.
Nephrolithiasis, a common urinary system disorder, exhibits high morbidity and recurrence rates, correlating with renal dysfunction and the increased risk of chronic kidney disease. Nonetheless, the precise role of disrupted cellular metabolism in renal injury induced by calcium oxalate (CaOx) crystal deposition is unclear. The purpose of this study is to investigate the involvement of the ubiquitin-like protein containing PHD and RING finger structural domain 1 (UHRF1) in CaOx-induced renal fibrosis and its impacts on cellular lipid metabolism.
Various approaches, including snRNA-seq, transcriptome RNA-seq, immunohistochemistry, and western blot analyses, were employed to assess UHRF1 expression in kidneys of nephrolithiasis patients, hyperoxaluric mice, and CaOx-induced renal tubular epithelial cells. Subsequently, knockdown of UHRF1 in mice and cells corroborated its effect of UHRF1 on fibrosis, ectopic lipid deposition (ELD) and fatty acid oxidation (FAO). Rescue experiments using AICAR, ND-630 and Compound-C were performed in UHRF1-knockdown cells to explore the involvement of the AMPK pathway. Then we confirmed the bridging molecule and its regulatory pathway in vitro. Experimental results were finally confirmed using AICAR and chemically modified si-UHRF1 in vivo of hyperoxaluria mice model.
Mechanistically, UHRF1 was found to hinder the activation of the AMPK/ACC1 pathway during CaOx-induced renal fibrosis, which was mitigated by employing AICAR, an AMPK agonist. As a nuclear protein, UHRF1 facilitates nuclear translocation of AMPK and act as a molecular link targeting the protein phosphatase PP2A to dephosphorylate AMPK and inhibit its activity.
This study revealed that UHRF1 promotes CaOx -induced renal fibrosis by enhancing lipid accumulation and suppressing FAO via inhibiting the AMPK pathway. These findings underscore the feasible therapeutic implications of targeting UHRF1 to prevent renal fibrosis due to stones.
肾结石是一种常见的泌尿系统疾病，发病率和复发率都很高，与肾功能障碍及慢性肾脏病风险增加相关。然而，细胞代谢紊乱在草酸钙（CaOx）晶体沉积所致肾损伤中的确切作用尚不清楚。本研究旨在探讨含PHD和RING指结构域1的泛素样蛋白（UHRF1）在CaOx诱导的肾纤维化中的作用及其对细胞脂质代谢的影响。
采用多种方法，包括单细胞核RNA测序（snRNA-seq）、转录组RNA测序、免疫组织化学和蛋白质免疫印迹分析，评估UHRF1在肾结石患者、高草酸尿小鼠和CaOx诱导的肾小管上皮细胞肾脏中的表达。随后，在小鼠和细胞中敲低UHRF1，证实了其对纤维化、异位脂质沉积（ELD）和脂肪酸氧化（FAO）的影响。在UHRF1敲低细胞中使用AICAR、ND-630和Compound-C进行挽救实验，以探究AMPK途径的参与情况。然后我们在体外证实了桥接分子及其调节途径。最后在高草酸尿小鼠模型体内使用AICAR和化学修饰的si-UHRF1证实了实验结果。
机制上，发现在CaOx诱导的肾纤维化过程中，UHRF1会阻碍AMPK/ACC1途径的激活，而使用AMPK激动剂AICAR可缓解这种情况。作为一种核蛋白，UHRF1促进AMPK的核转位，并作为靶向蛋白磷酸酶PP2A的分子连接物，使AMPK去磷酸化并抑制其活性。
本研究表明，UHRF1通过抑制AMPK途径增强脂质积累并抑制FAO，从而促进CaOx诱导的肾纤维化。这些发现强调了靶向UHRF1预防结石所致肾纤维化的潜在治疗意义。
