LncRNA TTTY15 regulates hypoxia-induced vascular endothelial cell injury via targeting miR-186-5p in cardiovascular disease

OBJECTIVE: Dysfunction of vascular endothelial cells was associated with diverse human diseases, including cardiovascular disease. Long noncoding RNAs (LncRNAs) were involved in the regulation of cell injury. We aimed to investigate the role of lncRNA testis-specific transcript, Y-linked 15 (TTTY15) in hypoxia-induced cell injury in human umbilical vein endothelial cells (HUVECs). MATERIALS AND METHODS: Cell counting kit-8 (CCK8) assay was used to check cell viability. Lactate dehydrogenase (LDH) assay kit and flow cytometry were utilized to evaluate the leakage rate of LDH and cell apoptosis, respectively. The protein levels of Cyclin D1 and B-cell lymphoma-2-Associated X (Bax) in hypoxia-induced HUVECs were measured by Western blot. Quantitative Real-time polymerase chain reaction (qRT-PCR) was conducted to detect the expression levels of TTTY15 and miR-186-5p in hypoxia-induced HUVECs. The starBase was utilized to predict the binding sites between TTTY15 and miR-186-5p and the dual-luciferase reporter assay was performed to verify the interaction. RESULTS: Hypoxia inhibited cell viability and promoted the release of LDH and cell apoptosis in HUVECs. Besides, hypoxia significantly decreased the protein level of Cyclin D1 and increased the protein level of Bax in HUVECs. In addition, the expression level of TTTY15 was obviously upregulated in hypoxia-induced HUVECs, opposite to the level of miR-186-5p. Meanwhile, knockdown of TTTY15 or upregulation of miR-186-5p mitigated hypoxia-induced cell injury in HUVECs. Further studies suggested that TTTY15 targeted miR-186-5p and regulated hypoxia-induced cell injury via interacting with miR-186-5p in HUVECs. CONCLUSIONS: Downregulation of TTTY15 ameliorated hypoxia-induced cell injury by targeting miR-186-5p in HUVECs.