Effect and mechanism of plasminogen activator inhibitor-1 on cardiomyocytes apoptosis stimulated by palmitate / 解放军医学杂志

ABSTRACT

Objective To investigate the effect and mechanism of plasminogen activator inhibitor-1(PAI-1) on cardiomyocytes apoptosis stimulated by palmitate. Methods Mouse primary cardiomyocytes were isolated and cultured, and then divided into control group and palmitic acid (PA) group, the expressions of PAI-1, apoptotic protein cleaved-caspase 3 and BCL2-associated X protein (Bax) were examined using Western blotting. PAI-1 low expression cells and over expression cells were established, and the expressions of PAI-1, cleaved-caspase 3 and Bax were examined by real-time PCR and Western blotting. After PAI-1 siRNA conditions were determined, cells were stimulated with palmitate, and then divided into four groups including control, PAI-1 low expression group, palmitate group and PAI-1 low expression+palmitate group. Western blotting was performed to examine the expressions of cleaved-caspase 3, Bax and phosphorylated-nuclear factor kappa-B (p-NF-κB). At last, the cells in palmitate group were given with NF-κB inhibitor Bay11-7082, and then divided into palmitate group, PAI-1 low expression + palmitate group, Bay11- 7082 + palmitate group, and PAI-1 low expression + Bay11-7082 + palmitate group, then the expressions of cleaved-caspase 3 and Bax were detected by Western blotting. Results The expressive levels of cleaved-caspase 3, Bax and PAI-1 were significantly higher in palmitate group than those in control group (P<0.01). The expressions of cleaved-caspase 3, Bax and p-NF-κB were obviously lower in PAI-1 low expression+palmitate group than those in palmitate group (P<0.01). Besides, the expressions of cleaved-caspase 3 and Bax were obviously lower in Bay11-7082+palmitate group than those in palmitate group (P<0.01), and the expressions of cleaved-caspase 3 and Bax were markedly lower in PAI-1 low expression+Bay11-7082+palmitate group than those in Bay11- 7082+palmitate group (P<0.01). Conclusion By affecting the NF-?B pathway, PAI-1 could involve in the apoptosis regulation of palmitate stimulated cardiomyocytes.