Effect of SGLT2 Inhibitors and Hypoxia-Inducible Factor-Prolyl Hydroxylase Inhibitors (HIF-PHIs) on Gene Expression and Metabolomic Profile of Podocytes

Background: Podocyte injury and loss under hyperglycemia contribute to the progression of diabetic kidney disease (DKD). Sodium-glucose cotransporter 2 inhibitors (SGLT2i) and hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHI) have pleiotropic properties, it remains obscure how the metabolic reprogramming in podocyte by SGLT2 inhibition and HIF stabilization affect podocyte abnormalities in DKD. We studied the effects of SGLT2i and HIF-PHI on transcriptome and metabolomic profile of podocytes under high glucose. Methods: Conditionally immortalized human podocytes were incubated in 5 mmol/L or 25 mmol/L glucose for a duration of 48 hrs, with the addition of dapagliflozin 11 nM and or roxadustat 30 μM. Targeted cellular metabolome analysis was conducted by capillary electrophoresis time of flight mass spectrometer (CE-TOF/MS) and capillary electrophoresis-triple quadrupole mass spectrometry (CE-QqQMS), 116 metabolites were quantified. Transcriptome analysis was conducted by RNA sequencing. Results: Hierarchical clustering analysis of RNA transcriptome and principal component analysis (PCA) of metabolomic data for podocytes treated with high glucose, dapagliflozin, roxadustat, or their combination indicated the groups were separated into distinct clusters. High glucose upregulated the gene sets of fatty-acid, amino-acid, and glucose metabolism, specifically glycolysis and gluconeogenesis. With dapagliflozin, roxadustat or the combination, gene set enrichment analysis (GSEA) indicated that they have additive effects to restore the fatty-acid, amino-acid, and glucose metabolism. Metabolome analysis indicated that high glucose resulted in a marked increase in metabolites involved with glycolysis and significant changes in the citric acid cycle, pentose phosphate pathway, glyoxylate and dicarboxylate metabolism. These metabolic effects were substantially altered by treatment with dapagliflozin, roxadustat, or both. Podocyte exposed to high glucose conditions decreased the arginine biosynthesis significantly, dapagliflozin and/or roxadustat treatment reversed the changes. Conclusion: Dapagliflozin and roxadustat restore podocyte carbohydrate metabolism, amino acids profile and arginine biosynthesis alterations under high glucose. SGLT2 inhibition and HIF stabilization are potential interventions for the dysregulated podocyte energy metabolism in DKD. Funding: Government Support – Non-U.S.