Investigation On The Effect Of Hydrogen Sulfide On Human Umbilical Vascular Endothelial Cells Senescence And Mechanism Involved

AimsA number of studies have suggested that aging is an independent risk factor forthe development of cardiovascular disorders. Physiological functions were declinedwith the age. Oxidative stress is the primary cause of endothelial cell senescencewhich is the basic of endothelial aging. The goal of the present study was toinvestigate the role of H2S in endothelial cell senescence and to explore thepreliminary mechanism of H2S against aging.Methods and Results1. An immunohistochemical analysis using anti-factor VIII antibody demonstratedthat the umbilical cord cells that we isolated from newborns were endothelial cells.2. The senescence of human umbilical vascular endothelial cells （HUVECs） wasinduced by incubating them in25μmol/L of H₂O₂for1hour. Light microscopyconfirmed the typical features of senescent HUVECs including an increased cell sizeand cytoplasmic granularity，SA-β-gal activity in the H₂O₂–treated HUVECs wasenhanced by120%， the proportion of HUVECs in the G0/G1phase were increased， Western blot analysis indicated p21level increased in the H₂O₂–treated HUVECs.3. HUVECs were pretreated with different concentrations of NaHS， Then treatedwith H₂O₂.Our study have shown that SA-β-gal positive cells were reduced comparedto the H₂O₂group，the proportion of HUVECs in the G0/G1phase was reduced（53.8±5.1%），while the proportion of HUVECs in the S phase was increased（32.1±3.4%）. In addition，the functions of HUVECs proliferation and migration wereenhanced.4. HUVECs were treated with NAM plus NaHS， the number of SA-β-gal positivecells were enhanced compared to the NaHS group. The functions of Cell proliferation and migration were attenuated.5. Furthermore，SIRT1protein level and activity were assessed by western blot andSIRT1activity assay kit to determine whether H2S regulates SIRT1against HUVECssenescence， the result demonstrated SIRT1levels in senescence HUVECs treatedwith NaHS were indistinguishable from controls， but SIRT1enzyme activity wasenhanced.ConclusionsThe present study demonstrated that H2S protects against HUVECs senescenceinduced by H₂O₂, which mechanism may involve regulation of SIRT1activity.