MiR-145-5p targeting TLR4 participates in inflammation and oxidative stress of atherosclerosis foam cells / 中华老年心脑血管病杂志

ABSTRACT

Objective To explore the role of microRNA-145-5p(miR-145-5p)in the regulation of inflammatory response and oxidative stress process in cellular model of atherosclerosis.Methods Human monocytic leukemia THP-1 cells-derived foam cells were constructed in vitro.Then,the relative expression of miR-145-5p in the model and control groups of cells were detected by qRT-PCR.TargetScan database was used to predict the targeting relationship between miR-145-5p and Toll-like receptor 4(TLR4).The 293T cells were divided into wild-type+mimic group,wild-type+mimic negative control(NC)group,and mutant+mimic group,mutant+mimic NC group,and dual luciferase assay was employed to verify the targeting relationship of miR-145-5p and TLR4.Foam cells were cultured in vitro and divided into miR-145-5p mimic group,mimic NC group,miR-145-5p inhibitor group,and inhibitor NC group according to the corresponding treat-ments.The expression of TLR4 at mRNA and protein levels was detected by qRT-PCR and Wes-tern blotting.The contents of TNF-α,IL-1β and IL-6 were detected by ELISA.Biochemical reagent kits were applied for generation of reactive oxygen species(ROS),content of MDA and activity of SOD.Results The expression of miR-145-5p was significantly reduced in the model group than the control group(0.29±0.01 vs 1.00±0.08,t=11.180,P＜0.01).Dual luciferase assay showed that luciferase activity was significantly lower in the miR-145-5p mimic group than the mimic NC group(t=8.612,P＜0.01).Compared with the mimic NC group,the mimic group had obviously lower mRNA and protein levels of TLR4 and contents of TNF-α,IL-1β,lL-6,ROS and MDA,and higher miR-145-5p expression level and SOD activity(P＜0.05,P＜0.01).The treatment of inhibi-tor resulted in increased TLR4 mRNA and protein levels and TNF-α,IL-1β,IL-6,ROS and MDA contents,and decreased miR-145-5p expression and SOD activity when compared with the above levels in the inhibitor NC group(P＜0.05,P＜0.01).Conclusion MiR-145-5p inhibits inflamma-tion and oxidative stress in cellular model of atherosclerosis by targeting TLR4.