Objectives To investigate the effects of statin, possessed pleiotropic cardioprotective effects, on cardiomyocytes apoptosis induced by TNF-α and the potential mechanisms involved.
Methods Cardiomyocytes isolated from neonatal rats were pretreated with rosuvastatin and followed by incubation with or without TNF-α. Cellular apoptosis was analysed by TUNEL assay, Hochest staining and caspase-3 activity detection. Expression level of miR-210 was determined by real-time PCR and the activity of NF-κB pathway was determined by Western-bolt. Up-regulation or knockdown of miR-210 was addressed by lentivirus transfection. The role of NF-κB in TNF-α induced cell apoptosis was also identified through the incubation of specific agonist to NF-κB pathway.
Results Compared with the control group, exposure to TNF-α resulted in a notably increase in cell apoptosis (5.42 ± 1.67% vs. 38.4 ± 6.77%, P<0.05), expression of cleaved caspase-3 (1.00 ± 0.38 vs. 3.78 ± 0.85, P<0.05) and activation of NF-κB pathway (1.00 ± 0.45 vs. 4.37 ± 0.66, P<0.05), while these effects could be significantly reduced by pretreatment with rosuvastatin. Inhibition experiment using NF-κB specific agonist reversed the anti-apoptotic effect of rosuvastatin (15.3 ± 6.48% vs. 26.3 ± 5.79%, P<0.05), indicating the cardioprotective effect of rosuvastatin, at least partly, dependent on NF-κB signalling. Real-time PCR showed that TNF-α incubation decreased the expression of miR-210 (1.00 ± 0.26 vs. 0.57 ± 0.38, P<0.05) in cardiomyocytes and this decrease was reversed by the pretreatment of rosuvastatin in a dose-dependent way. Overexpression of miR-210 decreased cardiomyocytes apoptosis induced by TNF-α (19.6 ± 6.68% vs. 33.5 ± 3.84%, P<0.05), similarly to statin pretreatment. Most importantly, the anti-apoptotic effect of rosuvastatin was significantly reduced by the transfection of antigomiR-210 (15.8 ± 4.28% vs. 30.7 ± 5.22%, P<0.05), which was statistically abolished by a putative target RGMA knockdown (30.7 ± 5.22% vs. 20.3 ± 3.38%, P<0.05).
Conclusions Rosuvastatain protected cardiomyocytes from TNF-α induced apoptosis through the inhibition of NF-κB pathway and upregulation of miR-210.