1,25(OH)_2D_3对人血管平滑肌细胞TLR4基因及炎症因子表达的抑制作用

Regulation of TLR4 and inflammatory cytokines by 1,25(OH)_2D_3 in human vascular smooth muscle cells

目的探讨1,25（OH）2D3（1,25-dihydroxyvitamin D3）对人主动脉血管平滑肌细胞（human aortic vascular smooth muscle cell,HA-VSMC）果蝇样受体（Toll like receptor 4,TLR4）基因及其下游炎症因子IL-6、IL-8和MCP-1表达的调节作用。方法不同浓度1,25（OH）2D3干预HA-VSMC后,采用实时荧光定量PCR法检测细胞TLR4、IL-6、IL-8、MCP-1mR-NA的表达水平。结果 1,25（OH）2D3在浓度为1-20nmol/L之间抑制TLR4、IL-6、IL-8、MCP-1mRNA水平的表达且具有明显的剂量依赖关系。在浓度为1nmol/L时1,25（OH）2D3下调TLR4和MCP-1mRNA表达的作用最明显,浓度为10nmol/L时,1,25（OH）2D3下调IL-6mRNA表达的作用最明显,浓度为20nmol/L时,1,25（OH）2D3下调IL-8mRNA表达的作用最明显。TLR4、IL-6、IL-8和MCP-1mRNA表达的最大下调幅度分别为对照组的3.08、2.39、3.19、2.23倍（均P〈0.05）。结论 1,25（OH）2D3通过下调TLR-4信号抑制了人主动脉血管平滑肌细胞的炎症反应。

Objective To investigate the regulation of TLR4 and its downstream inflammatory cytokines by 1,25（OH）2D3 in human aortic vascular smooth muscle cells （HA-VSMC）. Methods HA-VSMC were cultured and treated with various doses of 1,25 （OH）2D3, the cells were then harvested, total RNA were isolated for study of TLR4,IL-6,IL-8,MCP-1 mRNA expression by quantitative real-time PCR. Results 1,25 （OH）2D3 downregulate mRNA expression of TLR4,IL-6,IL-8 and MCP-1 in HA-VSMC. The mRNA expression levels of TLR4 and MCP-1 were all maximumly downregulated after treated by lnmol/L 1,25 （OH）ED3. The mRNA expression level of IL-6 was markedly downregulated after treated by 10nmol/L 1,25 （OH）2D3. The mRNA expression level of IL-8 was significantly downregulated after treated by 20nmol/L 1,25 （OH）2D3.TLR4,IL-6,IL-8 and MCP-1 mRNA ex- pression were downregulated by 3.08 fold,2.39 fold,3.19 fold and 2.23 fold respectively as compared with that of control （all P〈0.05 ）. Conclusion 1,25（OH）2D3 inhibitor TLR4 and it＇s downstream inflammatory cytokines expression in HA-VSMC, indicated that 1,25 （OH）：D3 plays an important role in inflammation of HA-VSMC through TLR4 pathway.