Targeted Metabolomics Reveals a Metabolic Signature Derived From the Stimulation of Cells With the Specific AT2R Agonist C21.

AIM: Despite increasing evidence for the cardiometabolic protective effects of angiotensin II Type 2 receptor (AT2R) activation, the underlying molecular mechanisms remain incompletely understood. This study aimed to determine how AT2R activation modulates cellular metabolism and to identify pathways relevant to its tissue-protective actions.

METHODS

3T3-L1 adipocytes, endothelial cells, and renal proximal tubular epithelial cells were treated with the specific AT2R agonist Compound 21 (C21). Targeted liquid chromatography-tandem mass spectrometry was used to quantify amino acids and metabolites involved in energy metabolism and redox homeostasis. Functional analyses included nitrate/nitrite determination and cystathionine β-synthase (CBS) activity.

RESULTS

Compound 21 induced shared and cell type-specific metabolic changes. Arginine, citrulline, glucose, and glyceraldehyde 3-phosphate increased consistently across all cell types, whereas citrate decreased. Sulfur-containing metabolites and glutathione-related intermediates increased predominantly in adipocytes and renal cells. Pathway analysis highlighted three metabolic axes affected by C21: arginine biosynthesis, central carbon metabolism, and amino acid-linked redox pathways. Functionally, C21 increased nitrate/nitrite accumulation in BAECs and CBS activity in RPTECs.

CONCLUSION

Treatment with C21 was associated with a conserved metabolic signature across adipocytes, renal epithelial cells, and endothelial cells involving arginine biosynthesis, central carbon metabolism, and amino acid-linked redox homeostasis. While the response differed among cell types, coordinated changes in arginine, citrulline, glucose, glyceraldehyde 3-phosphate, citrate, and GSH-related metabolites suggest that AT2R signaling is associated with cellular pathways involved in nitric oxide metabolism, energy metabolism, and redox homeostasis. Increased NOx production in BAECs and CBS activity in RPTECs support the cell type-specific metabolic effects of C21.