Long non coding RNA-UCA1 contributes to cardiomyocyte apoptosis by suppression of p27 expression.

Urothelial carcinoma-associated 1 (UCA1) is a recently identified long non coding RNA (lncRNA). However, few studies have explored its role in cardiomyocytes after focal cardiac ischemia reperfusion injury (CIR). Rat CIR models were established using ligation of the Lower Anterior Descending artery (LAD). Cell apoptosis and reactive oxygen species (ROS) production in cardiac tissues were explored using immunohistochemistry and DHE staining. lncRNA expression patterns were detected using microarray and validated by qPCR. Cell viability and apoptosis were examined using MTT assay and flow cytometry. CIR significantly induced cell apoptosis and ROS production in the rat model. The results of microarray demonstrated the reduced expression of UCA1, which was validated by qPCR. Follow-up experiments showed that UCA1 was involved in H2O2-induced cell apoptosis. We further showed that UCA1 negatively correlated with the expression of p27. Moreover, overexpression of p27 could induce primary cardiomyocyte apoptosis. Reduction of UCA1 levels plays a pro-apoptotic role in primary cardiomyocytes partially through stimulation of p27 protein expression. These results are in agreement with the observed levels of UCA1, p27 and apoptosis after cardiac I/R injury, suggesting that UCA1 might have an important role during I/R injury.