MicroRNA-99a-5p alleviates atherosclerosis via regulating Homeobox A1.

MicroRNAs have been demonstrated to be involved in the development of atherosclerosis. The present study aimed to evaluate the effect of miR-99a-5p and its target gene Homeobox A1 (HOXA1) in atherosclerosis. The biological functions of miR-99a-5p on human aortic smooth muscle cells (ASMCs) were assessed by MTT, wound healing and transwell assays. The target genes of microRNAs were predicted by TargetScan and miRDB. The binding of miR-99a-5p and HOXA1 was confirmed by luciferase reporter assay. In the in vivo study, high-fat diet-induced atherosclerosis model was established in Apolipoprotein E knockout mice. Hematoxylin-eosin (H&E), oil Red O and Masson trichrome staining were performed for determination of atherosclerotic lesion. The levels of miR-99a-5p and HOXA1 mRNA were detected by real-time PCR. HOXA1 and migration-associated protein levels were detected by western blot or immunohistochemistry analysis. MiR-99a-5p inhibited HOXA1 expression by targeting 3'UTR of HOXA1 mRNA. Enforced HOXA1 significantly promoted the proliferation, migration, and invasion of ASMCs. Furthermore, miR-99a-5p overexpression inhibited the proliferation, migration, and invasion of ASMCs stimulated by HOXA1, whereas miR-99a-5p inhibition reversed the effects of HOXA1 knockdown on these behaviours of ASMCs. In vivo, the specific overexpression of miR-99a-5p significantly abated atherosclerotic lesions formatted, accompanied with a significant down-regulation of HOXA1 mRNA and protein expression levels. We demonstrate for first time that miR-99a-5p may serve as a potential inhibitor of the atherosclerosis, and miR-99a-5p plays its role partially through targeting HOXA1.

Han Z ，Guan Y ，Liu B ，Lin Y ，Yan Y ，Wang H ，Wang H ，Jing B ... -  《-》

MicroRNA-99a inhibits tumor aggressive phenotypes through regulating HOXA1 in breast cancer cells.

Wang X ，Li Y ，Qi W ，Zhang N ，Sun M ，Huo Q ，Cai C ，Lv S ，Yang Q ... -  《Oncotarget》

MiR-99a suppressed cell proliferation and invasion by directly targeting HOXA1 through regulation of the AKT/mTOR signaling pathway and EMT in ovarian cancer.

Zhang L ，Liu XL ，Yuan Z ，Cui J ，Zhang H ... -  《-》

miR-99a-5p: A Potential New Therapy for Atherosclerosis by Targeting mTOR and Then Inhibiting NLRP3 Inflammasome Activation and Promoting Macrophage Autophagy.

MicroRNAs have been revealed to be involved in the development of atherosclerosis. The present study is aimed at exploring the potential of miR-99a-5p as a therapy for atherosclerosis. We suspected that miR-99a-5p might inhibit NLRP3 inflammasome activation and promote macrophage autophagy via constraining mTOR, therefore, alleviating atherosclerosis. The cell viability in ox-LDL-induced THP-1 macrophages was assessed by CCK-8 assay. Bioinformatic analysis was used to predict the target genes of miR-99a-5p. The binding between miR-99a-5p and mTOR was confirmed by luciferase reporter assay. In vivo, a high-fat-diet-induced atherosclerosis model was established in apolipoprotein E knockout mice. Hematoxylin-eosin, oil red O, and Sirius red staining were performed for the determination of atherosclerotic lesions. MTOR and associated protein levels were detected by Western blot analysis. miR-99a-5p inhibited NLRP3 inflammasome activation and promoted macrophage autophagy by targeting mTOR. Enforced miR-99a-5p significantly reduced the levels of inflammasome complex and inflammatory cytokines. Furthermore, miR-99a-5p overexpression inhibited the expression of mTOR, whereas mTOR overexpression reversed the trend of the above behaviors. In vivo, the specific overexpression of miR-99a-5p significantly reduced atherosclerotic lesions, accompanied by a significant downregulation of autophagy marker CD68 protein expression. We demonstrated for the first time that miR-99a-5p may be considered a therapy for atherosclerosis. The present study has revealed that miR-99a-5p might inhibit NLRP3 inflammasome activation and promote macrophage autophagy by targeting mTOR, therefore, alleviating atherosclerosis.

Wang G ，Jing SY ，Liu G ，Guo XJ ，Zhao W ，Jia XL ，Zheng MQ ，Tan WY ... -  《-》

MiR-155-5p inhibits the proliferation and migration of VSMCs and HUVECs in atherosclerosis by targeting AKT1.

Chen L ，Zheng SY ，Yang CQ ，Ma BM ，Jiang D ... -  《-》