Effect Of MIR-145on CD40Expression In Atherosclerosis And Protective Mechanism Of Curcumin

Background:Atherosclerosis is the primary initiator of many cardiovascular and cerebrovascular diseases and has been widely considered multi-factorial chronic inflammatory process. CD40, a kind of transmembrane glycoprotein with40-50kd, belongs to the tumor necrosis factor receptor family (TNF-R), which exists in a variety kinds of cells, CD40L, the ligand of CD40, triggers downstream signaling pathway via activating CD40,finally to promote the expression of proinflammatory and thrombosis gene, which has a pivotal role in the process of cardiovascular and cerebrovascular diseasesand. MicroRNAs (miRNA) is a small non-coding RNA, consisting of about19to25nucleotides, Binding with the mRNA3’-UTR region of a target gene, fianally leads to the degradation of mRNA and protein of the target gene. By using bioinformation methods, it has been found that CD40may be an important target genes of miR-145. Curcumin belongs to yellow acidic phenolics extracted from turmeric plant, which have multiple pharmacological effects such as anti-inflammation, endothelial protection, and anti-tumor effects.Objective:This study aimed at exploring the expression levels of miR-145in patients with atherosclerotic cerebral infarction, and the effects of curcumin and simvastatin on miR-145and CD40expression challenged by high levels of Hcy in peripheral blood mononuclear cells (PBMCs).Method:Blood plasma and PBMCs was Collected from both the control group and patients with atherosclerotic cerebral infarction. Using real-time PCR to detect the expression of miR-145in both Blood plasma and PBMCs; PBMCs were transfected with miR-145mimics and measured the expression levels of CD40and miR-145; PBMCs extracted from subjects are devided into six groups:normal control group、group with treatment of1×10-3mol·L-1Hcy、 different concentrations of curcumin groups、group with treatment of1×10-5mol·L-1simvastatin、then miR-145and CD40mRNA expression in PBMCs were detected by Real-time PCR, CD40protein expression was detected using Western Blot.Results:1.Patients with atherosclerotic cerebral infarction showed significantly higher expression levels of miR-145both in plasma and PBMCs than normal control group;2.After transfecting PBMCs with miR-145mimics, there was a significant rise of miR-145expression in PBMCs, accompanied with a reduce in CD40mRNA expression;3. Incubation of PBMCs with1X10-5Hcy mol·L-1for24hours, can significantly inhibit the expression of miR-145, accompanied by a rise in CD40mRNA and protein expression in PBMCs, pretreatment with curcumin and simvastatin can partly reverse the effects induced by Hcy.Conclusion:1. After patients with atherosclerotic cerebral infarction being treated in hospital, There was a significant increase expression levels of miR-145both in plasma and PBMCs;2. Curcumin and simvastatin can inhibit the expression of CD40mRNA and protein by regulating the levels of miR-145in PBMCs induced by Hcy.