Impaired glycolysis-derived serine metabolism as a key driver of podocyte injury with senescence.

Chronic kidney disease (CKD) is a major health issue, with podocyte injury with senescence playing a central role in glomerulosclerosis. This study investigates the link between glycolysis-derived serine metabolism and podocyte injury with senescence, focusing on the role of phosphoglycerate kinase 1 (PGK1) in the regulation of L-serine synthesis and podocyte homeostasis. Using in vivo and in vitro models, we examined the effects of angiotensin II (Ang II)-induced metabolic dysregulation on serine metabolism and its impact on podocyte function. The results demonstrate that Ang II downregulates PGK1 expression through the transcription factor FOXA1, leading to reduced L-serine biosynthesis, mitochondrial dysfunction, and increased cellular senescence in podocytes. Supplementing with L-serine or enhancing PGK1 expression in podocytes alleviated these pathological changes, restored mitochondrial function, and reduced senescence-associated phenotypes in CKD mouse models. Moreover, PGK1 was found to interact with keratin, type II cytoskeletal 1 (KRT1), stabilizing the cytoskeletal integrity of podocytes. These findings identify a novel metabolic pathway linking glycolysis, serine metabolism, and podocyte injury with senescence, suggesting that targeting the PGK1-serine axis may offer therapeutic potential for slowing podocyte senescence and CKD progression.