Downregulation of linc00961 contributes to promote proliferation and inhibit apoptosis of vascular smooth muscle cell by sponging miR-367 in patients with coronary heart disease.

OBJECTIVE: Atherosclerosis is one of the most important risk factors for coronary heart disease (CHD), and growing evidence has shown that long non-coding RNAs (lncRNAs) can serve as prospective markers for atherosclerosis. In this study, we mainly focused on the potential roles of linc00961 in CHD patients. PATIENTS AND METHODS: qRT-PCR was used to detect the expressions of linc00961 and miR-367 in CHD patients and ApoE-/-mice, and the correlations were analyzed. Then, HA-VAMC was respectively treated with 5 inflammatory factors and hypoxia conditions to explore the factors that affect linc00961 levels. Furthermore, the linc00961 overexpression lentivirus (LV-linc00961) and linc00961 downregulation lentivirus (LV-sh linc00961) were purchased and transfected into human vascular smooth muscle cells (VSMCs). CCK8 assay was carried out to measure the cell proliferation of VSMC, and the levels of Cyclin D1, Bcl-2, Bax, and cleaved caspase-3 were detected by RT-PCR and Western blot. Moreover, the Luciferase assay was performed to explore the binding site of linc00961 and miR-367. Finally, the miR-367 inhibitor was transfected into LV-sh linc00961 VSMCs to confirm the linc00961 functions via miR-367.
RESULTS: We found that linc00961 was significantly decreased in patients with CHD and ApoE-/-mice. Additionally, linc00961 was reduced in VSMCs at the conditions of hypoxia and C-reactive protein (CRP). Most importantly, the overexpression of linc00961 significantly inhibited the VSMCs proliferation, repressed the levels of Cyclin D1 and Bcl-2, and increased the levels of Bax and cleaved caspase-3. However, the downregulation of linc00961 promoted VSMCs proliferation, increased the levels of Cyclin D1 and Bcl-2, and repressed the levels of Bax and cleaved caspase-3. We also found that miR-367 was downregulated following the upregulation of linc00961, while it was upregulated following the downregulation of linc00961. The Luciferase gene reporter assay indicated that linc00961 could directly bind with miR-367 in VSMCs. Finally, we found that linc00961 could inhibit proliferation and promote apoptosis of VSMCs via binding with miR-367.
CONCLUSIONS: According to the results, our study revealed that linc00961 was significantly decreased in patients with CHD and ApoE-/-mice. Furthermore, our findings firstly uncovered that linc00961 was reduced by hypoxia and CRP in VSMCs. The downregulation of linc00961 contributed to promote proliferation and inhibit apoptosis of VSMCs by sponging miR-367 in CHD patients, which might provide a potential target for treating atherosclerosis.