Expression of caspase-3 and transposition of Omi/HtrA2 in H9C2 by erythropoietin and/or Omi/HtrA2 silencing / 西安交通大学学报(医学版)

ABSTRACT

Objective To observe the expression of caspase-3 and transposition of Omi/HtrA2 in H9C2 by erythropoietin and/or Omi/HtrA2 silencing to explore the related anti-apoptotic mechanisms.Methods The cultured H9C2 cardiomyocytes were divided into control group,H/R group (anoxia 2 h and re-oxygenation 24 h), and different concentrations of EPO treatment groups.The release rate of lactate dehydrogenase (LDH)in cell supernatant was measured in each group.Expressions of cleaved caspase-3 and Omi/HtrA2 were measured by Western blot;then the transposition of Omi/HtrA2 between cytoplasm and mitochondria was observed.Specific siRNA interfering fragment was transfected into H9C2 cardiomyocytes by liposome method.Its silencing effect on Omi/HtrA2 was measured by RT-PCR and Western blot.The survival rate,release rate and expression of cleaved caspase-3 were measured.And the expression of Omi/HtrA2 was measured in cytoplasm and mitochondria in H9C2 (transposition of Omi/HtrA2 ).Results Compared with H/R group,the release of LDH and expression of cleaved caspase-3 were decreased; the transposition of Omi/HtrA2 from mitochondria to cytoplasm in H/R treatment groups was increased compared with control group,while that in EPO (20 IU/mL)group decreased.si-HtrA2 group transfected with siRNA showed a decreased release of LDH and expression of cleaved caspase-3 with all significant variances (P <0.05).Conclusion EPO exerts a cytoprotective effect by inhibiting the transposition of Omi/HtrA2 and hence the activation of caspases-3 pathway.