Ertugliflozin Mitigates Renal Ischemia-Reperfusion Injury through the Downregulation of HIF-1α Expression

Introduction: Renal ischemia-reperfusion (I/R) injury can lead to acute kidney injury. SGLT-2 inhibitors, commonly used as hypoglycemic agents, have demonstrated the ability to mitigate cardiac I/R injury. Some studies have indicated that SGLT-2 inhibitors may safeguard renal tubular epithelial cells from damage caused by high glucose levels via mitochondrial mechanisms. SGLT-2 inhibitors alleviate renal hypoxia and cellular stress and enhance nutrient deprivation signaling. These combined effects may account for their inhibition of HIF-1α and activation of HIF-2α, which in turn leads to increased erythropoiesis, while also preventing organelle dysfunction, inflammation, and fibrosis. Our aim is to verify the efficacy of ertugliflozin in alleviating renal ischemia-reperfusion injury and to explore its potential protective mechanism.

Methods: HK-2 cells were exposed to hypoxia for 16 h, followed by a 3 h re-oxygenation period (H16R3), with or without ertugliflozin treatment. The activity and phenotype of HK-2 cells were detected by using detection methods such as CCK-8 assay, mitochondrial membrane potential detection, flow cytometry, and protein electrophoresis. It was determined through cell immunofluorescence staining, RNA interference experiments, and gene overexpression transfection experiments that ertugliflozin alleviated H/R-induced HK-2 cell damage by inhibiting HIF-1α in the HIF-1α-iNOS-NO pathway. In in vivo experiments, the bilateral renal pedicles were occluded using a vascular clamp for 25 min to induce renal ischemia. After 24 h post-operation, the mouse was continuously administered ertugliflozin by gavage until the third day after the operation. The total duration of ertugliflozin administration was 8 days. Blood samples and kidney tissues of the mouse were collected. Qualitative and quantitative analyses of mouse histological specimens were conducted through experiments such as enzyme-linked immunosorbent assay, H&E staining, immunohistofluorescence staining, and immunohistochemical staining.

Results: This study analyzed the effects of ertugliflozin on kidney I/R from both cellular and animal model perspectives. Transcriptome Sequencing was used to screen the HIF-1 signaling pathway as the relevant signaling pathway through which ertugliflozin exerts its renal protective effect. RNA interference experiments and gene overexpression plasmid transfection experiments were conducted to clarify that ertugliflozin exerts corresponding renal protective effects in renal tubular epithelial cells and kidney I/R-induced renal injury through the HIF-1α site in the HIF-1α-Inos pathway.

Conclusion: Our study provides compelling preliminary evidence that ertugliflozin may improve I/R-induced acute kidney injury by downregulating HIF-1α. This study provides some reference value for the treatment and management of renal I/R injury.

Ertugliflozin; HIF-1α; HK-2 cell; Ischemia-reperfusion injury; Renal hypoxia.