Dexmedetomidine Reduces Apoptosis And HIF-1? Protein Expression In H9C2 Cells After H/R Injury

Objective To observe the effect of Dexmedetomidine(DEX)preconditioning and postconditioning on HIF-1? and apoptosis in H9C2 cardiomyocytes after hypoxia/reoxygenation(H/R)injury.Methods H9C2 cardiomyocyte lines were cultured in vitro.The experiment was randomly divided into 5 groups,normal control group(C group);hypoxia and reoxygenation injury group(H/R group);DEX pretreatment group(1?M)(D-pre+H/R group);DEX post-treatment group(1 ?M)(D-post + H/R group).The viability of cardiomyocytes was detected by CCK-8 assay.The activity of lactate dehydrogenase(LDH)was detected by 2,4-dinitrophenylhydrazine colorimetry.Morphological changes and fluorescence intensity of myocardial cells are observed by inverted fluorescence microscope.The expression of HIF-1? mRNA was detected by qRT-PCR,and the protein expression of HIF-1?,Bax,and Bcl-2 was detected by Western Blot.Results Compared with group C,the survival rate of cardiomyocytes in H/R group,DEX(1?M)pretreatment group(D-pre+H/R group),DEX(1?M)post-treatment group(D-post+H/R group)are significantly decreased(p<0.01),while LDH activity and cardiomyocyte apoptosis were increased(p<0.01).protein expression of Bcl-2 was decreased(p<0.01),Bax protein expression level was increased(p<0.01).Both HIF-1? mRNA level and HIF-1? protein expression were increased(p<0.01);compared with H/R group,D-pre+H/R Group,D-post+H/R group can significantly increase the survival rate of cardiomyocytes,reduce the activity of LDH and cell apoptosis(p<0.01),the expression level of Bax protein was decreased(p<0.01),Bcl-2 Protein expression levels(p<0.01)was increased.Although HIF-1? mRNA expression levels did not change,HIF-1? protein expression levels were reduced(p<0.01).Inverted fluorescence microscopy showed that: cells in H/R group were significantly reduced and rounding,and the fluorescence intensity of HIF-1? and Bax was significantly enhanced.Compared with cells in H/R,D-pre+H/R group and D-post+H/R group,the fluorescence intensity of HIF-1? and Bax was reduced,Conclusion Dexmedetomidine preconditioning and postconditioning both reduce apoptosis and HIF-1? protein expression in H9C2 cells after H/R injury...