Effect of miR-21 on rat thoracic aortic aneurysm model by regulating the expressions of MMP-2 and MMP-9

OBJECTIVE: To explore the mechanism underlying micro ribonucleic acid (miR)-21 in the invasion of rat aortic aneurysm cells in vitro by regulating matrix metalloproteinase (MMP)-2 and MMP-9. MATERIALS AND METHODS: Rats were randomly divided into three groups: control group, model group, and miR-21 group. Real Time fluorescence quantitative Polymerase Chain Reaction (qRT-PCR) was adopted to detect the levels of miR-21 in each group of cells, transwell assay was performed to measure the effect of miR-21 on the invasion of aortic aneurysm cells. Western blotting was used to examine the expression of PTEN, which is the predicted target of miR-21 in aortic aneurysm cells, as well as the expressions of invasion- related proteases, MMP-2 and MMP-9. RESULTS: The expression level of miR-21 in thoracic aortic aneurysm cells in model group was significantly higher than that in normal group (p<0.05), and that in miR-21 group was remarkably higher than that in model group (p<0.05). MiR-21 group had evidently more aortic aneurysm cells and stronger cell invasion ability than normal group and model group (p<0.05). In addition, the expression level of PTEN in model group was significantly higher than that in normal group (p<0.05), while that in miR-21 group notably declined compared to model group, (p<0.05). Compared with normal group and model group, the expressions of MMP-2 and MMP-9 were markedly increased in miR-21 group (p< 0.05). CONCLUSIONS: In aortic aneurysm cells of rats, miR-21 could suppress the expression of PTEN and activate MMP-2 and MMP-9 signals to promote the proliferation and migration of aortic aneurysm cells.