RESUMO
Transfer RNA selenocysteine 1 associated protein 1 (Trnau1ap) serves an essential role in the synthesis of selenoproteins, which have critical functions in numerous biological processes. Selenium deficiency results in a variety of diseases, including cardiac disease. However, the mechanisms underlying myocardial injury induced by selenium deficiency remain unclear. The present study examined the effects of Trnau1ap under and overexpression in cardiomyocytelike H9c2 cells, by transfection with small interfering RNA and an overexpression plasmid, respectively. Expression levels of glutathione peroxidase, thioredoxin reductase and selenoprotein K were decreased in Trnau1apunderexpressing cells, and increased in Trnau1apoverexpressing cells. Using MTT, proliferating cell nuclear antigen, annexin V and caspase3 activity assays, it was demonstrated that reducing Trnau1ap expression levels inhibited the proliferation of H9c2 cells and induced apoptosis. Conversely, increasing Trnau1ap expression levels promoted cell growth. Western blot analysis revealed that the phosphoinositide 3kinase/protein kinase B signaling pathway was activated in Trnau1apunderexpressing cells. Furthermore, the apoptotic pathway was activated in these cells, evidenced by relatively greater expression levels of Bcell lymphoma (Bcl2)associated X protein and reduced expression levels of Bcl2. Taken together, these findings suggest that Trnau1ap serves a key role in the proliferation and apoptosis of H9c2 cells. The present study provides insight into the underlying mechanisms of myocardial injury induced by selenium deficiency.