Metabolomic profiling in kidney cells treated with a sodium glucose-cotransporter 2 inhibitor

Abstract

We aimed to determine the metabolomic profile of kidney cells under high glucose conditions and following sodium-glucose cotransporter 2 (SGLT2) inhibitor treatment. Targeted metabolomics using the Absolute IDQ-p180 kit was applied to quantify metabolites in kidney cells stimulated with high glucose (25 and 50 mM) and treated with SGLT2 inhibitor, dapagliflozin (2 µM). Primary cultured human tubular epithelial cells and podocytes were used to identify the metabolomic profile in high glucose conditions following dapagliflozin treatment. The levels of asparagine, PC ae C34:1, and PC ae C36:2 were elevated in tubular epithelial cells stimulated with 50 mM glucose and were significantly decreased after 2 µM dapagliflozin treatment. The level of PC aa C32:0 was significantly decreased after 50 mM glucose treatment compared with the control, and its level was significantly increased after dapagliflozin treatment in podocytes. The metabolism of glutathione, asparagine and proline was significantly changed in tubular epithelial cells under high-glucose stimulation. And the pathway analysis showed that aminoacyl-tRNA biosynthesis, arginine and proline metabolism, glutathione metabolism, valine, leucine and isoleucine biosynthesis, phenylalanine, tyrosine, and tryptophan biosynthesis, beta-alanine metabolism, phenylalanine metabolism, arginine biosynthesis, alanine, aspartate and glutamate metabolism, glycine, serine and threonine metabolism were altered in tubular epithelial cells after dapagliflozin treatment following 50 mM glucose compared to those treated with 50 mM glucose.

Figure 1

Sparse partial-least-squares discriminant analysis (sPLS-DA) of metabolites detected in tubular epithelial cells (a), podocytes (b), respectively, treated with glucose (25, 50 mM) compared to those without treatment (control). sPLS-DA in 2D scoring plot with 95% confidence interval.

Figure 2

Sparse partial-least-squares discriminant analysis (sPLS-DA) of metabolites detected in tubular epithelial cells (a), podocytes (b), respectively, treated with 2 µM dapagliflozin following 50 mM glucose compared to those without treatment (control) and compared to those treated with 50 mM glucose. sPLS-DA in 2D scoring plot with 95% confidence interval.

Figure 3

Box plots of differentially expressed metabolite levels in tubular epithelial cells treated with 2 µM dapagliflozin following 50 mM glucose compared to the levels of metabolite identified in those without treatment or treated with 50 mM glucose. *p < 0.05 indicates the significant difference between the groups by unpaired nonparametric Mann–Whitney test.

Figure 4

Box plots of differentially expressed metabolite levels in podocytes treated with 2 µM dapagliflozin following 50 mM glucose compared to the level of metabolite identified in those without treatment or treated with 50 mM glucose. *p < 0.05 indicates the significant difference between the groups by unpaired nonparametric Mann–Whitney test.

Figure 5

The metabolic pathways analysis for metabolites expressed in tubular epithelial cells treated with 50 mM of glucose compared to those without treatment (control) was performed using MetaboAnalyst. All the matched pathways in KEGG database are displayed as circles. The color and size of each circle represents p value and pathway impact value, respectively.

Figure 6

The metabolic pathways analysis for metabolites expressed in tubular epithelial cells treated with 2 µM dapagliflozin following 50 mM glucose compared to the level of metabolite identified in those treated with 50 mM glucose was performed using MetaboAnalyst. All the matched pathways in KEGG database are displayed as circles. The color and size of each circle represents p value and pathway impact value, respectively.