Protective Effects of Hydrogen Sulfide in the Ageing Kidney

Aims. The study aimed to examine whether hydrogen sulfide (H₂S) generation changed in the kidney of the ageing mouse and its relationship with impaired kidney function. Results. H₂S levels in the plasma, urine, and kidney decreased significantly in ageing mice. The expression of two known H₂S-producing enzymes in kidney, cystathionine γ-lyase (CSE) and cystathionine-β-synthase (CBS), decreased significantly during ageing. Chronic H₂S donor (NaHS, 50 μmol/kg/day, 10 weeks) treatment could alleviate oxidative stress levels and renal tubular interstitial collagen deposition. These protective effects may relate to transcription factor Nrf2 activation and antioxidant proteins such as HO-1, SIRT1, SOD1, and SOD2 expression upregulation in the ageing kidney after NaHS treatment. Furthermore, the expression of H₂S-producing enzymes changed with exogenous H₂S administration and contributed to elevated H₂S levels in the ageing kidney. Conclusions. Endogenous hydrogen sulfide production in the ageing kidney is insufficient. Exogenous H₂S can partially rescue ageing-related kidney dysfunction by reducing oxidative stress, decreasing collagen deposition, and enhancing Nrf2 nuclear translocation. Recovery of endogenous hydrogen sulfide production may also contribute to the beneficial effects of NaHS treatment.