WWP2 MEDIATES THE METABOLIC REPROGRAMMING OF RENAL MYOFIBROBLASTS TO PROMOTE KIDNEY FIBROSIS [scRNA-seq]

Renal fibrosis is a common pathological endpoint that is challenging to reverse in chronic kidney disease (CKD) independently of the underlying causes. Although myofibroblasts are mainly responsible for the accumulation of a fibrillar collagen-rich extracellular matrix (ECM), recent reports revealed their heterogeneity in proliferative and fibrotic activities, mirroring specific metabolic states that drive fibrosis. Here, we investigate the role of E3 ubiquitin-protein ligase WWP2 in the metabolic reprogramming of renal myofibroblasts in fibrosis. The tubulointerstitial expression of WWP2 contributes to the progression of fibrosis in CKD patients and in pre-clinical models of CKD. WWP2 deficiency leads to increased fatty acid oxidation, boosting mitochondrial respiration, promoting myofibroblast proliferation and arresting pro-fibrotic activation, thus ameliorating kidney fibrosis. Specifically, WWP2 suppresses the transcription of PGC-1alpha, which mediates the metabolic and proliferative changes in fibrotic myofibroblasts. Pharmacological intervention targeting PGC-1alpha reverses the pro-fibrotic effect of WWP2. These findings reveal a previously unappreciated WWP2-PGC-1alpha axis underlying the metabolic reprogramming of myofibroblasts during renal fibrosis, which could provide a new target for therapeutic intervention in CKD. Kidneys from wwp2 knockout and wildtype mice were collected and processed according to 10X Genomics Chromium protocol for single-cell RNAseq.肾纤维化是慢性肾脏病（chronic kidney disease, CKD）中常见的病理终点，无论潜在病因如何，其逆转均极具挑战性。尽管肌成纤维细胞（myofibroblasts）主要负责富含原纤维胶原蛋白的细胞外基质（extracellular matrix, ECM）的沉积，但近期研究揭示了该类细胞在增殖与纤维化活性层面的异质性，这与驱动纤维化进展的特定代谢状态密切相关。本研究聚焦于E3泛素蛋白连接酶WWP2（E3 ubiquitin-protein ligase WWP2）在肾纤维化过程中肾肌成纤维细胞代谢重编程的调控作用。在慢性肾脏病患者及相关临床前模型中，WWP2在肾小管间质的表达可促进纤维化进展。WWP2基因缺失会增强脂肪酸氧化过程、提升线粒体呼吸功能，进而促进肌成纤维细胞增殖并阻滞其促纤维化激活，最终改善肾纤维化状态。具体而言，WWP2可抑制PGC-1α（PGC-1alpha）的转录，而该因子正是介导纤维化肌成纤维细胞代谢与增殖改变的关键分子。靶向PGC-1α的药理学干预手段，可逆转WWP2介导的促纤维化效应。本研究揭示了一条此前未被报道的WWP2-PGC-1α信号轴，其参与肾纤维化进程中肌成纤维细胞的代谢重编程，可为慢性肾脏病的治疗干预提供全新靶点。本研究按照10X Genomics Chromium平台的实验流程，对wwp2基因敲除小鼠与野生型小鼠的肾脏组织进行采集与处理，用于开展单细胞RNA测序（single-cell RNAseq）。