Changes in expressions of miR-22-3p and MMP-9 in rats with thoracic aortic aneurysm and their significance

H.-M. Zhao, L. Jin, Y. Liu, X. Hong

Department of Vascular Surgery, China-Japan Union Hospital of Jilin University, Changchun, China. hongxin824206@sina.com

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• Cardiology

OBJECTIVE: The purpose of this study was to explore the changes in the expressions of micro ribonucleic acid (miR)-22-3p and matrix metalloproteinase-9 (MMP-9) in rats with thoracic aortic aneurysm (TAA) and their significance.

MATERIALS AND METHODS: A total of 16 specific pathogen-free Sprague-Dawley female rats were randomly divided into normal group (n=8) and angiotensin II (Ang II) group (n=8). Ang II was perfused using the micro pump in Ang II group, while the same amount of normal saline was perfused in the normal group. After continuous intervention, the tumor formation rate in the thoracic aorta was observed, and the expression of miR-22-3p was detected via Reverse Transcription-Polymerase Chain Reaction (RT-PCR) in both groups. Other 16 rats were selected and randomly divided into agomiR-22-3p group (n=8) and control group (n=8). In the agomiR-22-3p group, agomiR-22 and Ang II were continuously injected via angular vein. In the control group, agomiR negative control was injected, and Ang II was continuously perfused. After intervention for 4 weeks, the tumor formation rate in the thoracic aorta was observed, and the expression of MMP-9 was determined via immunofluorescence and immunohistochemistry in both groups.

RESULTS: After intervention for 4 weeks, the expression of miR-22-3p in Ang II group was significantly lower than that in normal group (p<0.05). After drug administration for 4 weeks, agomiR-22-3p group had a lower tumor formation rate (p<0.05) and a lower expression of MMP-9 than the control group (p<0.05).

CONCLUSIONS: The expression of miR-22-3p declines in TAA rats, and miR-22-3p can inhibit the expression of MMP-9, thus suppressing the formation of TAA in rats.

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