ATGL regulates renal fibrosis by reprogramming lipid metabolism during the transition from AKI to CKD

Acute kidney injury (AKI) can progress to chronic kidney disease (CKD) and subsequently to renal fibrosis. Poor repair of renal tubular epithelial cells (TECs) after injury is the main cause of renal fibrosis. Studies have shown that restoring damaged fatty acid β-oxidation (FAO) can reduce renal fibrosis. Adipose triglyceride lipase (ATGL) is a key enzyme that regulates lipid hydrolysis. This study, for the first time, demonstrated that ATGL was downregulated in the renal TEC in the AKI-CKD transition mouse model. Moreover, treatment with the ATGL inhibitor atglistatin exacerbated lipid accumulation and downregulated the FAO level and mitochondrial function, while it increased the level of oxidative stress injury and apoptosis, resulting in aggravated renal fibrosis. In contrast, ATGL overexpression suppressed lipid accumulation, improved the FAO level and mitochondrial function, and attenuated oxidative stress and apoptosis, thereby ameliorating fibrosis in vitro and in vivo. In summary, ATGL regulates renal fibrosis by reprogramming lipid metabolism in renal TECs. This study provided new avenues and targets for treating CKD.