Effect of HIF-1in Cardiomyocytes during Hypoxia and Reoxygenation Injury and the Study of Signal Transduction and Drug Intervention
|Keywords||cardiomyocytes hypoxia/reoxygenation injury hypoxia induciblefactor-1 atorvastatin PI3K signaling pathway|
Objective To observe the effect of atorvastatin (ATV) and wortmannin (WT) oncardiomyocytes during hypoxia and reoxygenation injury and influence of HIF-1α、VEGF、GLUT-1and HO-1mRNA. Discussing the mechanisms of protection ofatorvastatin and PI3K signaling pathway in cardiomyocytes during hypoxia andreoxygenation injury, providing new ideas for the prevention and treatment inmyocardial ischemia/reperfusion injury clinically.Methods Cardiomyocytes from SD rats(1～3d) were separated for primary culture;Immunocytochemical identification of myocardial cells were carried out; to establishhypoxia/reoxygenation model; The cardiomyocytes cultured on the third day weredivided into five groups randomly: Control group、H/R group、H/R+ATV group、H/R+WT group and H/R+ATV+WT group. The cardiomyocytes morphologicalchanges were observed under an inverted microscope and counting cell beating rate;to use the MTS assay to detect the cell livability; the level of serum troponin I (cTnI)was detected by chemiluminescence immunoassay analyzer; using SYBR GREENfluorescent quantitative PCR to detect the expression of HIF-1α、VEGF、GLUT-1and HO-1mRNA.Results (1) Cardiocytes began to adhere and grow after4～6h.The cardiocytesshowed fusiform, rhombus or polygon shape after24h. After48h, cell clusters weretaken shape with actinomorphic arrangement. Cardiocytes stretched out parapodiumsto link together and beated spontaneously and rhythmically after72h. Beating of cellsis up to peak on the fourth day by beating frequency among100～120/min.Since the seventh day, beating frequency was reduced gradually.(2) The hypoxia/reoxygenationmodel was built successfully.(3) Compared with group Control, beating rate and celllivability of group H/R decreased obviously (P <0.05), serum troponin I was higherclearly (P <0.05), the expression of HIF-1α、VEGF、GLUT-1and HO-1mRNA wereincreased significantly(P <0.05); compared with group H/R, beating rate and celllivability of group H/R+ATV increased obviously (P <0.05), serum troponin I wasclearly lower (P <0.05), the expression of HIF-1α、VEGF、GLUT-1and HO-1mRNAwere significantly higher (P <0.05); beating rate and cell livability of group H/R+WTdecreased significantly (P <0.05), serum troponin I was obviously higher (P <0.05),and the expression of HIF-1α、VEGF、GLUT-1and HO-1mRNA were significantlylower (P <0.05) comparing with group H/R; beating rate and cell livability of groupH/R+ATV+WT beating rate and cell livability decreased clearly (P <0.05), serumtroponin I was obviously higher (P <0.05), the expression of HIF-1α、VEGF、GLUT-1and HO-1mRNA were significantly lower (P <0.05) comparing with group H/R+ATV.Conclusion HIF-1may regulate its target genes to protect cardiomyocytes in-duced by during hypoxia and reoxygenation injury;The activation of PI3K sign-aling pathways can induce the expression of HIF-1α and its downstream targetgenes VEGF、GLUT-1and HO-1, participating in the protection of cardiomyoc-ytes induced by hypoxia/reoxygenation injury; the inhibiting action of atorvasta-tin on cardiomyocytes’ injury induced by hypoxia/reoxygenation may be relatedwith the activation on the PI3K signaling pathway that can induce the express-ion of HIF-1α、VEGF、HO-1and GLUT-1mRNA.