Anserine and Carnosine Induce HSP70-Dependent H 2 S Formation in Endothelial Cells and Murine Kidney

Anserine and carnosine have nephroprotective actions; hydrogen sulfide (H 2 S) protects from ischemic tissue damage, and the underlying mechanisms are debated. In view of their common interaction with HSP70, we studied possible interactions of both dipeptides with H 2 S. H 2 S formation was measured in human proximal tubular epithelial cells (HK-2); three endothelial cell lines (HUVEC, HUAEC, MCEC); and in renal murine tissue of wild-type (WT), carnosinase-1 knockout (Cndp1 -KO) and Hsp70 -KO mice. Diabetes was induced by streptozocin. Incubation with carnosine increased H 2 S synthesis capacity in tubular cells, as well as with anserine in all three endothelial cell lines. H 2 S dose-dependently reduced anserine/carnosine degradation rate by serum and recombinant carnosinase-1 (CN1). Endothelial Hsp70 -KO reduced H 2 S formation and abolished the stimulation by anserine and could be restored by Hsp70 transfection. In female Hsp70 -KO mice, kidney H 2 S formation was halved. In Cndp1 -KO mice, kidney anserine concentrations were several-fold and sex-specifically increased. Kidney H 2 S formation capacity was increased 2–3-fold in female mice and correlated with anserine and carnosine concentrations. In diabetic Cndp1 -KO mice, renal anserine and carnosine concentrations as well as H 2 S formation capacity were markedly reduced compared to non-diabetic Cndp1 -KO littermates. Anserine and carnosine induce H 2 S formation in a cell-type and Hsp70-specific manner within a positive feedback loop with CN1.