MiR-106b-5p Inhibits Tumor Necrosis Factor-α-induced Apoptosis by Targeting Phosphatase and Tensin Homolog Deleted on Chromosome 10 in Vascular Endothelial Cells

Background: Apoptosis of endothelial cells (ECs) plays a key role in the development of atherosclerosis and there are also evidence indicated that phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a viable target in therapeutic approaches to prevent vascular ECs apoptosis. Aberrant miR-106b-5p expression has been reported in the plasma of patients with unstable atherosclerotic plaques. However, the role and underlying mechanism of miR-106-5p in the genesis of atherosclerosis have not been addressed. In this study, we explored the anti-apoptotic role of miR-106-5p by regulating PTEN expression in vascular ECs. Methods: Real-time reverse transcription polymerase chain reaction (RT-PCR) was performed to detect the expression levels of miR-106b-5p in human atherosclerotic plaques and normal vascular tissues. Human umbilical vein endothelial cells (HUVEC) were transfected with miR-106b-5p mimic or negative control mimic, and apoptosis was induced by serum starvation and tumor necrosis factor-α (TNF-α) treat. Western blotting and real-time RT-PCR experiments were used to detect PTEN expression levels and TNF-α-induced apoptosis was evaluated by the activation of caspase-3 and cell DNA fragmentation levels in HUVEC. Results: The expression of miR-106b-5p was significantly downregulated in plaques than in normal vascular tissues. TNF-α significantly downregulated miR-106b-5p expression levels and upregulated activation of caspase-3 and cell DNA fragmentation levels in HUVEC. Overexpression of miR-106b-5p with miR-106b-5p mimic inhibited PTEN expression and TNF-α-induced apoptosis in HUVEC. Luciferase reporter assays confirmed that miR-106b-5p binds to PTEN mRNA 3' untranslated region site. Conclusion: MiR-106b-5p could inhibit the expression of PTEN in vascular ECs, which could block TNF-α-induced activation of caspase-3, thus prevent ECs apoptosis in atherosclerosis diseases.