The ubiquitin ligase NEDD4-2/NEDD4L regulates both sodium homeostasis and fibrotic signaling to prevent end-stage renal disease
Jantina Manning, Sonia S. Shah, Andrej Nikolic, Tanya L. Henshall, Yeesim Khew‐Goodall, Sharad Kumar
Abstract
Abstract Kidney disease progression can be affected by Na + abundance. A key regulator of Na + homeostasis is the ubiquitin ligase NEDD4-2 and its deficiency leads to increased Na + transport activity and salt-sensitive progressive kidney damage. However, the mechanisms responsible for high Na + induced damage remain poorly understood. Here we show that a high Na + diet compromised kidney function in Nedd4-2 -deficient mice, indicative of progression toward end-stage renal disease. Injury was characterized by enhanced tubule dilation and extracellular matrix accumulation, together with sustained activation of both Wnt/β-catenin and TGF-β signaling. Nedd4-2 knockout in cortical collecting duct cells also activated these pathways and led to epithelial–mesenchymal transition. Furthermore, low dietary Na + rescued kidney disease in Nedd4-2 -deficient mice and silenced Wnt/β-catenin and TGF-β signaling. Our study reveals the important role of NEDD4-2-dependent ubiquitination in Na + homeostasis and protecting against aberrant Wnt/β-catenin/TGF-β signaling in progressive kidney disease.