[Effect of ryanodine receptor 2 gene silencing on ischemia-reperfusion injury of rat myocardial cells].

Objectives: To block the synthesis of ryanodine receptor 2 (RyR2) in myocardial cells by RNA interference and to investigate its biological impact on ischemia-reperfusion (I/R) in rat myocardial cells.

Methods: Rat myocardial cells were isolated and cultured for an I/R model in vitro. RNA interference technique was used to block the synthesis of RyR2 in myocardial cells. Changes of LDH level, apoptosis, RyR2 mRNA expression and cytosolic Ca(2+) concentration were analyzed accordingly.

Results: Myocardial cells after I/R manipolation were severely injuried (LDH leakage, 125 IU/L vs 12 IU/L, P < 0.05), apoptosis (60.1% vs 5.5%, P < 0.05), significant cytosolic Ca(2+) overload (21.2 vs 7.6, P < 0.05) and remarkable mitochondrial membrane potential loss (37.2 vs 85.1, P < 0.05). However, no visible change of RyR2 was observed (20.1 vs 22.7, P > 0.05). Pre-treatment with RyR2 specified siRNA demonstrated suppressed expression of RyR2 (6.8 vs 20.1, P < 0.05), increased mitochondrial membrane potential (55.8 vs 37.2, P < 0.05), attenuated cytosolic Ca(2+) overload (8.6 vs 21.2) and cellular apoptosis (31.2% vs 60.1%, P < 0.05).

Conclusion: RyR2 gene silencing enables to protect myocardial cells from I/R injury in vitro.