Study of EPO pretreatment's effect on expression of TNF-α gene in cultured cardiac myocytes with hypoxia/reoxygenation injury and the possible mechanism

Objective The present study is to investigate the effect of EPO pretreatment on TNF-α expression in cultured cardiac myocytes with H/R and to explore the possible NF-κB signal transduction mechanism. Methods The model of cultured cardiac myocytes with H/R was established and the cardiac myocytes were divided into 4 groups, including EPO group (treat with EPO 10?U/ml 24?h before H/R), EPO+PDTC group (treat with EPO 10?U/mL and PDTC 5?μg/ml 24?h before H/R), PDTC group (treat with PDTC 5?μg /ml 24h before H/R) and control group. Change of TNF-α gene expression before and after H/R in cardiac myocytes was detected with RT-PCR and western blot. Change of NF-κB activity before and after H/R in cardiac myocytes was assayed with EMSA. Results Before H/R, there was no significant difference in TNF-α mRNA and protein expression between the 4 groups and after H/R, TNF-α mRNA and protein expression increased significantly in the 4 groups compared to control group before H/R. After H/R, TNF-α mRNA and protein expression was lower in EPO group than in the other 3 groups. Before H/R, NF-κB activity was higher in EPO group than in the other groups. After H/R, NF-κB activity increased significantly in all the 4 groups compared to the control before H/R and NF-κB activity was lower in EPO group than in the other groups. Conclusion EPO pretreatment inhibited the upregulation of TNF-α gene expression after H/R in cardiac myocytes, which might be related to the inhibition of NF-κB activation; EPO pretreatment might inhibit the activation of NF-κB after H/R through the negative feed-back mechanism of NF-κB activation.