Glucose Deprivation-restoration Induces Labile Iron Overload and Ferroptosis in Renal Tubules Through V-ATPase-mTOR Axis-mediated Ferritinophagy and Iron Release by TPC2

Renal ischemia-reperfusion injury (IRI), a common complication following kidney transplantation and partial nephrectomy, is the leading cause of renal dysfunction with limited treatment. Excessive cellular iron accumulation drives lipid peroxidation and activates pathways associated with ferroptosis, which has been implicated in renal IRI. However, the regulatory mechanisms of cellular iron metabolism and its relationship with ferroptosis during ischemia-reperfusion (IR) remain unclear. In this study, in vitro OGSD-R (oxygen, glucose, and serum deprivation-restoration) models and in vivo IR models were employed to investigate alterations in iron metabolism, ferroptosis, and the underlying molecular mechanisms using immunofluorescence, immunoblotting and biochemical testing. We identified glucose deprivation-restoration (GD-R) as a key trigger of cellular iron overload under renal IR condition. Mechanistically, GD-R-induced iron overload is driven by the dysfunction of vacuolar ATPase (V-ATPase)-mammalian target of rapamycin (mTOR) pathway. Inactivation of mTOR results in lysosomal iron releases via two-pore channel 2 (TPC2) and ferritin degradation through ferritinophagy. This process elevates intracellular iron levels, thereby promoting ferroptosis in renal IRI. Targeting cellular iron metabolism effectively alleviates renal IRI. These findings highlight the critical role of glucose metabolism and V-ATPase-mTOR pathway in the regulation of iron homeostasis and ferroptosis during renal IRI, and establish a mechanistic link among glucose metabolism, iron overload and ferroptosis, providing potential therapeutic targets for renal IRI.