Xiaoyun Si1, Qixian Chen2, Jiechang Zhang3, Wei Zhou1, Lijun Chen4, Jingjing Chen1, Na Deng1, Wei Li1, Danan Liu1, Long Wang1, Linyan Shi1, Weihong Sun1, Haoyu Song5, Lintao Zhong6. 1. Department of Cardiology, Affiliated Hospital of Guizhou Medical University, No. 28 Guiyi Road, Guiyang 550004, Guizhou Province, China. 2. Department of Pulmonary and Critical Care Medicines, Zhuhai People's Hospital (Zhuhai Hospital affiliated with Jinan University), Zhuhai 519000, China. 3. Department of Cardiology, Zhuhai People's Hospital (Zhuhai Hospital affiliated with Jinan University), Zhuhai 519000, China. 4. Department of Hematology and Rheumatology, Zhuhai People's Hospital (Zhuhai Hospital affiliated with Jinan University), Zhuhai 519000, China. 5. Geriatrics Department, Zhuhai People's Hospital (Zhuhai Hospital affiliated with Jinan University), Zhuhai 519000, China. Electronic address: songhaoyu@gmc.edu.cn. 6. Department of Cardiology, Zhuhai People's Hospital (Zhuhai Hospital affiliated with Jinan University), Zhuhai 519000, China. Electronic address: zhonglintao@gmc.edu.cn.
Abstract
AIMS: Phenotypic switching of vascular smooth muscle cells (VSMCs) is essential for the formation of abdominal aortic aneurysms (AAAs). MicroRNA-23b (miR-23b) has recently been shown to play a vital role in maintaining the VSMC contractile phenotype; however, little is known about the role of miR-23b in the formation of AAAs. Here, we investigated whether miR-23b prevents AAA formation by inhibiting VSMC phenotypic switching. MATERIALS AND METHODS: We administered angiotensin II (Ang II, 1000 ng/kg/min) or vehicle to 10-12-week-old male apolipoprotein E knockout (ApoE-/-) or C57BL/6J mice via subcutaneous osmotic minipumps for 4 weeks. KEY FINDINGS: The expression of miR-23b was significantly reduced in the aorta during the early onset of AAA in angiotensin II-treated ApoE-/- mice and in human AAA samples. In vitro experiments showed that the suppression of SMC contractile marker gene expression induced by Ang II was accelerated by miR-23b inhibitors but inhibited by mimics. In vivo studies revealed that miR-23b deficiency in Ang II-treated C57BL/6J mice aggravated the formation of AAAs in these mice compared with control mice; the opposite results were observed in miR-23b-overexpressing mice. Mechanistically, miR-23b knockdown significantly increased the expression of the transcription factor forkhead box O4 (FoxO4) during VSMC phenotypic switching induced by Ang II. In addition, a luciferase reporter assay showed that FoxO4 is a target of miR-23b in VSMCs. SIGNIFICANCE: Our study revealed a pivotal role for miR-23b in protecting against aortic aneurysm formation by maintaining the VSMC contractile phenotype.
AIMS: Phenotypic switching of vascular smooth muscle cells (VSMCs) is essential for the formation of abdominal aortic aneurysms (AAAs). MicroRNA-23b (miR-23b) has recently been shown to play a vital role in maintaining the VSMC contractile phenotype; however, little is known about the role of miR-23b in the formation of AAAs. Here, we investigated whether miR-23b prevents AAA formation by inhibiting VSMC phenotypic switching. MATERIALS AND METHODS: We administered angiotensin II (Ang II, 1000 ng/kg/min) or vehicle to 10-12-week-old male apolipoprotein E knockout (ApoE-/-) or C57BL/6J mice via subcutaneous osmotic minipumps for 4 weeks. KEY FINDINGS: The expression of miR-23b was significantly reduced in the aorta during the early onset of AAA in angiotensin II-treated ApoE-/- mice and in human AAA samples. In vitro experiments showed that the suppression of SMC contractile marker gene expression induced by Ang II was accelerated by miR-23b inhibitors but inhibited by mimics. In vivo studies revealed that miR-23b deficiency in Ang II-treated C57BL/6J mice aggravated the formation of AAAs in these mice compared with control mice; the opposite results were observed in miR-23b-overexpressing mice. Mechanistically, miR-23b knockdown significantly increased the expression of the transcription factor forkhead box O4 (FoxO4) during VSMC phenotypic switching induced by Ang II. In addition, a luciferase reporter assay showed that FoxO4 is a target of miR-23b in VSMCs. SIGNIFICANCE: Our study revealed a pivotal role for miR-23b in protecting against aortic aneurysm formation by maintaining the VSMC contractile phenotype.
Authors: Daniel P Zalewski; Karol P Ruszel; Andrzej Stępniewski; Dariusz Gałkowski; Marcin Feldo; Janusz Kocki; Anna Bogucka-Kocka Journal: J Clin Med Date: 2022-06-16 Impact factor: 4.964