Injuries Of Homocysteine On Human Umbilical Vein Endothelial Cells And The Protection Of Betaine

ObjectiveTo study whether Betaine(Bet) could protect the human umbilical vascular endothelialcells (HUVECs) injured by high level of homocysteine(Hcy)；To observe the influence ofthe Bcl-2and Bax proteins’ expressions under Bet; To prove wether Bet could preventhyperhomocysteinemia-induced endothelial dysfuction though antioxidation by detectivingthe activity of SOD, the content of MDA and nitrie oxide.MethodHUVECs were cultured with RPMI-1640medium containing15%fetal bovine serum.When cells reach80%confluence, identified by immunofluorescence technique andpassaged. After the third generateon, select cells which were in the exponential phase oflive, and divided them into five groups:(1) normal control: join the same volume ofmedium as other groups;(2) Hcy damage group:1mmol/L Hcy;(3) low dosage Bet group:1mmol/L Hcy+10mmol/LBet;(4) middle dosage Bet group:1mmol/L Hcy+25mmol/LBet;(5) high dosage Bet group:1mmol/L Hcy+50mmol/L Bet; went on to treat them for24hours, then observed the shape of five gtoups with Phase contrast microscope andmeasured the viability of cells using MTT assay. The rate of apoptosis was determined byflow cytometric analysis. Immunohistochemical and Western blotting method were used todetect the Bcl-2and Bax protein’s expressions. Meanwhile, the activity of superoxidedismutase (SOD), the content of malondialdehyde (MDA) and nitrie oxide (NO) weredetected by appropriate kits.ResultsImmunocytochemical method showed that cells tested positive, identifying thereliability of our cell strain. High level of homocysteine could damage HUVECs obviouslyand triggered apoptosis of HUVECs. While in Bet groups, condition of HUVECs is improved. Bet could reduce both the rate of growth inhibition and the rate of apoptosissignificantly, increase Bcl-2protein’s expression and decrease Bax protein’s expressionobviously. The result of immunocytochemistry was similar to that fromimmunocytochemical method. Besides, Bet could increase the activity of SOD, decreasethe expression of MDA and increase NO’s expression which showed that Bet could protectHUVECs from oxidation dysfuction by high level of homocysteine.Conclusion1Bet could prevent apoptosis of HUVECs under homocystein of high concentrationand protect their activity.2The inhibition of Bet on apoptosis of HUVEC through increasing the expression ofBcl-2and decrease the expression of Bax.3Bet could exhibit its protective effects against HUVEC injury by inereasing theactivity of SOD, decreasinge the content of MDA and increasinge the content of NO inHUVECs under oxidative damage.