Acute Inactivation of the VHL Gene Contributes to Protective Effects of Ischemic Preconditioning in the Mouse Kidney

Background/Aims: The von Hippel-Lindau (VHL) protein functions as an E3 ubiquitin ligase, controlling the stability of hypoxia-inducible factor (HIF). Preinduction of HIF-1α before pathological insult activates a self-defense mechanism and suppresses further aggravation of organ or cellular injury by ischemia. We investigated whether acute inactivation of the VHL gene might play a role in the response of mice to ischemic renal injury. Methods: We generated tamoxifen-inducible conditional VHL knockout (VHL-KO) mice to inactivate the VHL gene in an acute manner during renal ischemia-reperfusion injury (IRI) induced by bilateral clamping of kidney arteries. Renal IRI is characterized by renal dysfunction and tubular damage. Results: After the procedure of IRI, blood urea nitrogen (BUN) and creatinine (CRN) levels in control mice were significantly higher (BUN, 138.10 ± 13.03 mg/dl; CRN, 0.72 ± 0.16 mg/dl) than in VHL-KO mice (BUN, 52.12 ± 6.61 mg/dl; CRN, 0.24 ± 0.04 mg/dl; BUN: p < 0.05; CRN: p < 0.05). Histologically, tubular injury scores were higher in control mice than in VHL-KO mice (p < 0.05). Conclusion: We suggest that the acute inactivation of the VHL gene contributes to protective effects of ischemic preconditioning in renal tubules of the mouse.