| [Objective] Atherosclerosis is a disorder of chronic inflammatory diseases interaction with lipid metabolism and inflammation.Macrophages lipid accumulation and inflammation are two key factors of this disease. Lipoprotein lipase is a rate-limiting enzyme in catalyzing and hydrolyzing triglyceridethe in lipase gene family, whereas macrophages LPL can promote macrophage accumulation of lipid and inflammatory factor expression, to promote the development of foam cell formation and As progression. Angiopoietin-like 4(Angptl4), a secreted protein, is an important regulator to irreversibly inhibit lipoprotein lipase(LPL) activity. It has been reported that macrophage ANGPTL4 suppresses LPL activity, foam cell formation and inflammatory gene expression to reduce atherosclerosis development. Recently years, there has been an increased number of miRNAs to be recognized as critical regulators of susceptibility, development and progression in the As development. The latest research shows that mi R-134 is closely related to the myocardial infarction disease, He and colleagues has found miR-134 is high expression in the vascular intima, plasma and macrophages, the mechanism of atherogenic development is still unclear. Through bioinformatics analysis we found that mi R-134 targeted ANGPTL4 biological basis, The purpose of this study was to investigate the role of miR-134 in the development of atherosclerosis and mechanism, provide a new research strategy and target treatment of atherosclerosis.[Methods]we analyzed miR-134 potential gene targets using different prediction programs,predict binding sites on microRNAs for a particular micro RNA-134 candidate gene, and ANGPTL4 binding sites,combined with a grade, stem ring structure and free energy score, etc. we performed 3'UTR luciferase reporter assay to investigate whether miR-134 directly targets ANGPTL4. Treatment with miR-134 mimic at different time(0?6, 12, 24, 48 h)and different concentrations(0, 10,20, 40, 80 nM) in macrophages. Using the kit of TG and HPLC method to detect miR-134 mimic affect the intracellular TG, TC, FC and the content of CE. To detection the role of mi R-134 in macrophages mediated lipid intake of receptor SR-A, CD36 expression and the LPL and LRP-1combining. Treatment with miR-134 mimic found the influence of secretion inflammatory cytokines in macrophages.[Results] Bioinformatics prediction results show that mi R- 134 highly conserved evolution in different species, multiple target sites prediction results show that the predicted comprehensive score is high.293 T cells transfection ANGPTL4 wild type and mutant 3 'UTR, the luciferase reporter assay revealed that the wild-type 3' UTR of ANGPTL4 exhibited a low translation level in the presence of miR-134. Comparedwith the control, decreased ANGPTL4 expression in both time and concentration- dependent manners. On the contrary, LPL activity and protein were dramatically increased. the macrophage scavenger receptors SR- A and CD36 expression were aslo increased. The levels of proinflammatory cytokine TNF-?, MCP-1 and IL-6 were significantly increased by treatment of cells with miR-134 mimic. However the antiinflammatory cytokines such as IL-10 was significant declined. In contrast, treatment with mi R-134 inhibitor resulted in a marked decrease in the secretion of TNF-?, MCP-1, IL-6, but IL-10 was significantly increased.[Conclusion] MicroRNA-134 actives lipoprotein lipase-mediated lipid accumulation and inflammatory response by targeting AngiopoietinLike 4 in THP-1 macrophages. |
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