ABSTRACT
Objective: To explore the effect of impaired cardiac microvascular endothelial cells on rat's embryo cardiomyocyte apoptosis and the impact of Tongxinluo in such process. Methods: 3 kinds conditioned medium of cardiac microvascular endothelial cells were prepared. ① normal rat's cardiac microvascular endothelial cell (RCMECs) conditioned medium, ②homocysteine induced impaired RCMECs conditioned medium and ③ Tongxinluo treated RCMECs conditioned medium. Rat's embryo H9c2 cardiomyocytes were divided into 4 groups:① Control group, cells were cultured in DMEM without serum, ② N-CM group, cells were cultured in RCMECs conditioned medium, ③ H-CM group, cells were cultured in homocysteine induced impaired RCMECs conditioned medium and ④ T-CM group, cells were cultured in Tongxinluo treated RCMECs conditioned medium. Cell mitochondrial membrane potential (MMP) was detected by JC-1 agent, ROS level was examined by flow cytometry, cardiomyocytes apoptosis was measured by live cell imaging system, expression levels of cytochrome C (Cyt-C), cysteinyl aspartate specific proteinase-3 (Caspase-3), Bcl-2 associated X protein (Bax) and B-cell leukemia/lymphoma 2 protein (Bcl-2) were detected by Western blot analysis. Results: MMP, expression levels of ROS, Cyt-C and cardiomyocyte apoptosis were similar between Control group and N-CM group, P>0.05. Compared with N-CM group, H-CM group had decreased MMP, increased ROS and cardiomyocyte apoptosis, up-regulated expressions of Cyt-C, Caspase-3 and Bax, all P<0.01. Compared with H-CM group, T-CM group had increased MMP, decreased ROS and cardiomyocyte apoptosis, down regulated expressions of Cyt-C, Caspase-3 and Bax, all P<0.05; while up-regulated expression of Bcl-2, P<0.01. Conclusion: Conditioned medium of impaired cardiac microvascular endothelial cells may induce cardiomyocyte apoptosis and such process could be inhibited by Tongxinluo.