Long non-coding RNA ROR mitigates cobalt chloride-induced hypoxia injury through regulation of miR-145.

Obstructive sleep apnoea-hypopnoea syndrome (OSAHS) is a condition causing apnea and hypopnea. LncRNA-ROR revealed properties in regulating hypoxia response. Our study explored the roles of ROR in CoCl2-induced hypoxia injury in HK-2 cells. HK-2 cells were treated with CoCl2 to induce hypoxia injury. Cell viability, cell apoptosis and apoptotic proteins were detected using CCK-8, flow cytometry and western blot, respectively. The alter expression of ROR and miR-145 was achieved through transfection. Moreover, the expressions of HIF-α and ERK and MAPK related factors were examined using western blot. We found that CoCl2 decreased cell viability and increased apoptosis as well as increased the expression of ROR. ROR overexpression increased cell viability, decreased cell apoptosis. ROR overexpression upregulated anti-apoptotic proteins Bcl-2 and decreased p53, Bax and cleaved-Caspase-3. ROR overexpression also increased the expression of HIF-α. On the opposite, ROR silence led to the opposite results as relative to ROR overexpression. ROR overexpression decreased expression of miR-145. Co-transfection with ROR overexpression and miR-145 impaired the promoting effects of ROR in CoCl2 treated cells. ROR increased phosphorylation of ERK while decreased phosphorylation of MAPK. In conclusion, lncRNA ROR alleviated CoCl2-induced hypoxia injury through regulation of miR-145 as well as modulating ERK and MAPK signalling. Highlights CoCl2 induces ROR upregulation; Overexpression of ROR reduces CoCl2-induced HK-2 cell injury; Silence of ROR promotes CoCl2-induced HK-2 cell injury; Overexpression of ROR decreases miR-145 expression; ROR overexpression modulates ERK and MAPK signalling pathways through regulation of miR-145.