Effect and Mechanism of Enarodustat on Delaying Renal Interstitial Fibrosis by Mediating Aerobic Glycolysis

Background: Renal interstitial fibrosis is a critical factor in the progression of chronic kidney disease and is associated with metabolic reprogramming such as aerobic glycolysis. The transcription factor Forkhead box protein K1 (FOXK1) has been reported to be involved in the regulation of aerobic glycolysis and tissue fibrosis. Enarodustat (JTZ-951), a hypoxia-inducible factor prolyl hydroxylase inhibitor, is widely used in the treatment of renal anemia. This study explores the potential of JTZ-951 to delay renal fibrosis by inhibiting the excessive activation of FOXK1 and the abnormally activated aerobic glycolysis. Methods: Mice were fed with JTZ-951 for 2 weeks before undergoing unilateral ureteral obstruction, ischemia-reperfusion injury, or folic acid injection to induce renal fibrosis. After 4 weeks of continued JTZ-951 feeding, kidney, serum, and urine samples were collected. Serum markers, kidney pathology, fibrosis markers, mitochondrial morphology, key enzymes of aerobic glycolysis, and expression of FOXK1 and HIF were evaluated. HK-2 cells were pre-treated with JTZ-951 and then stimulated with TGF-β1. The fibrotic phenotype, mitochondrial morphology, aerobic glycolysis markers, and expression of FOXK1 and HIF were observed. HK-2 cells were transfected with shRNA to knock down HIF expression. The effects of JTZ-951 on aerobic glycolysis, mitochondrial morphology, fibrotic response, and FOXK1 expression were evaluated. Results: Pathological staining showed increased kidney injury and collagen deposition in the renal fibrosis model groups compared to controls, with elevated creatinine and urea nitrogen levels. JTZ-951 feeding reduced these injuries and increased erythropoietin and hemoglobin levels compared to controls and model groups. Renal fibrosis markers, key enzymes of aerobic glycolysis, FOXK1, and HIF expression were upregulated in the renal fibrosis model groups, with mitochondrial damage in renal tubular epithelial cells. JTZ-951 feeding improved these phenomena. In vitro experiments yielded consistent results. After interfering with HIF expression in HK-2 cells using shRNA, supplementation with JTZ-951 did not significantly improve the above phenomena. Conclusion: JTZ-951 can inhibit the excessive activation of FOXK1 and the abnormally activated glycolysis, thereby delaying the progression of renal fibrosis.