DNA-PKcs drives CKD progression by activating TAF7/RAPTOR/mTORC1 signaling-mediated metabolic reprogramming

Kidney injury initiates epithelial dedifferentiation and myofibroblast activation during the progression of chronic kidney disease (CKD). Herein, we found that the expression of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) was significantly increased in the kidney tissues of both CKD patients and CKD mice induced by unilateral ureteral obstruction (UUO) and unilateral ischemia-reperfusion (UIR) injury. In vivo, knockout of DNA-PKcs or treatment with its specific inhibitor NU7441 hampered the development of CKD in mice. In vitro, DNA-PKcs deficiency preserved epithelial cell phenotype and inhibited fibroblast activation induced by transforming growth factor-beta 1 (TGF-beta-1). Additionally, our results showed that TBP-associated factor 7 (TAF7), as a possible substrate of DNA-PKcs, enhanced mTORC1 activation by upregulating RAPTOR expression, which subsequently promoted metabolic reprogramming in injured epithelial cells and myofibroblasts. Taken together, DNA-PKcs can be inhibited to correct metabolic reprogramming via the TAF7/mTORC1 signaling in CKD, and serve as a new target for treating CKD.