miRNA 146b-5p protects against atherosclerosis by inhibiting vascular smooth muscle cell proliferation and migration

Epigenomics ◽  
2020 ◽  
Author(s):  
Dating Sun ◽  
Gui Xiang ◽  
Jing Wang ◽  
Yuanyuan Li ◽  
Shuai Mei ◽  
...  

Aim: To explore the potentially important role of miRNA 146b-5p (miR-146b) during the development of atherosclerosis. Materials & methods: Proliferation, migration and luciferase assays and mouse models were used to determine the functions of miR-146b. Results: miR-146b was identified as substantially upregulated in the aortic plaques of ApoE-/- mice as well as in response to inflammatory cytokines. Overexpression of miR-146b repressed proliferation and migration of vascular smooth muscle cells by downregulating Bag1 and Mmp16, respectively. Adeno-associated virus-mediated miR-146b overexpression inhibited neointima formation after carotid injury and suppressed atherosclerotic plaque formation in western diet-induced ApoE-/- mice. Conclusion: miR-146b is a novel regulator of vascular smooth muscle cell function induced by inflammatory response, specifically in neointima formation, and offers a novel therapeutic strategy for treating atherosclerosis.

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Ning Shi ◽  
Xiao-Bing Cui ◽  
Shi-You Chen

Olfactomedin 2 (Olfm2) is a novel regulator for vascular smooth muscle cell (SMC) differentiation, but it is unclear whether Olfm2 is also involved in SMC phenotypic modulation, an important process associated with vascular injury. In this study, we found that Olfm2 was induced during PDGF-BB-induced SMC phenotypic modulation. Olfm2 knockdown attenuated PDGF-BB-induced suppression of SM marker genes including SM myosin heavy chain and SM22α, and also inhibited PDGF-BB-stimulated SMC proliferation and migration. On the other hand, Olfm2 overexpression down-regulated SM markers gene expression, and promoted SMC proliferation marker PCNA expression. Moreover, PDGF-BB slightly induced expression of Runx2, which interfered with the formation of SRF/myocardin ternary complex, but dramatically enhanced SRF-Runx2 interaction, suggesting that certain factors mediate SRF-Runx2 interaction. Indeed, Olfm2 physically interacted with both SRF and Runx2. Blockade of Olfm2 inhibited SRF association with Runx2, leading to increased association between SRF and myocardin, which in turn activated the transcription of SM markers, whereas overexpression of Olfm2 promoted SRF binding to Runx2. These results demonstrated that Olfm2 mediates the interaction between SRF and Runx2, contributing to SMC phenotypic modulation.


2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Yuming Li ◽  
Haitao Li ◽  
Xinfang Wang ◽  
Junya Wang ◽  
Zhongqiu Li

The current study was designed to explore the mechanisms of vascular smooth muscle cell (VSMC) proliferation and migration induced by adenosine diphosphate ribosyl cyclase(ADPRC). In this study, 32 Male ApoE-/- mice(6 weeks old, 18-22g)on a C57BL/6J background were divided into four groups, which received normal chow (n=8, NC group), high-fat Western-type diet (n=8, 0.25% cholesterol, 21% fat,HFD group), high-fat Western-type diet,infusion of 2,2′-dihydroxyazobenzene(DHAB, a ADPRC inhibitor, 2mg/kg/day, n=8, HFD-DHAB group) intraperitoneally or high-fat Western-type diet,infusion of LY294002(a Inhibitor of Akt, 5mg/kg/d, n=8, HFD-LY group) intraperitoneally, for 10 weeks. 8 male C57BL/6J mice served as control. After 10 weeks, mice were anesthetized with chloral hydrate, aorta was removed and immediately frozen in liquid nitrogen. Aortic atherosclerotic lesions, VSMC proliferation and migration were assessed by histomorphological observation, smooth muscle actin-α(α-SMA)and proliferating cell nuclear antigen (PCNA) examination. ADPRC expression and alterations of Akt, FOXO3a, phospho-FOXO3a and MMP-9 were determined by RT-PCR, Western Blot, Immunohistochemistry or Immunofluorescence. The results showed that, in aortic atherosclerotic lesions derived from atherosclerotic mice of HFD group, an increased VSMC proliferation and migration, reflected by the up-regulation of α-SMA and PCNA expression, were observed followed by increased expression of ADPRC, Akt, FOXO3a, phospho-FOXO3a and MMP-9. The enhanced expression of ADPRC and followed alterations of FOXO3a, phospho-FOXO3a, MMP-9 as well as α-SMA, PCNA, VSMC proliferation and migration were absent in NC group and C57BL/6J control mice. Treatment with DHAB or LY294002 reversed VSMC proliferation, migration and expression of Akt, FOXO3a, phospho-FOXO3a and MMP-9 in HFD-DHAB and HFD-LY group. These data shows that high-fat Western-type diet induced ADPRC may via PI3K-Akt to phosphorylate FOXO3a up-regulating MMP-9 to enhance vascular smooth muscle cell proliferation and migration in mice.


2019 ◽  
Vol 39 (3) ◽  
Author(s):  
Genqiang Fang ◽  
Jia Qi ◽  
Liya Huang ◽  
Xianxian Zhao

AbstractVascular remodeling caused by essential hypertension is a leading cause of death in patients, and vascular smooth muscle cell (VSMC) dysfunction and phenotypic switching result in vascular remodeling. Therefore, inhibiting cell dysfunction and phenotypic switching in VSMCs may be a new treatment strategy for essential hypertension. The aim of the current study is to explore the roles of long non-coding RNA (lncRNA) MRAK048635_P1 in VSMC function and phenotypic switching. The MRAK048635_P1 level was determined in spontaneously hypertensive rats (SHRs) and VSMCs isolated from SHRs. MRAK048635_P1 was knocked down using a specific siRNA in VSMCs isolated from the thoracic aorta of SHRs and Wistar–Kyoto rats. Then, the proliferation and migration of VSMCs were determined using a cell counting kit-8 (CCK-8), a 3H labeling method, a transwell assay, and a wound healing assay. Flow cytometry was used to test the effect of MRAK048635_P1 on VSMC apoptosis. The protein and mRNA levels of associated genes were measured through Western blotting, immunofluorescence, and Quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR). MRAK048635_P1 showed low expression during hypertension in vivo and in vitro. Down-regulation of lncRNA MRAK048635_P1 promoted proliferation and migration and inhibited apoptosis in VSMCs isolated from healthy rat vascular tissue and SHR-derived VSMCs. Importantly, we also found that down-regulation of MRAK048635_P1 could induce VSMC phenotypic switching from a contractile to a secretory phenotype. In conclusion, our findings reveal that decreased MRAK048635_P1 is probably an important factor for vascular remodeling by affecting VSMC cell function and phenotypic switching in essential hypertension.


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