尿酸刺激树突状细胞成熟与Toll样受体mRNA表达的关系

Expression of Toll-like receptors mRNA during the uric acid-stimulated maturation of dendritic cells

目的观察未成熟树突状细胞(DC)经尿酸刺激成熟过程中,Toll样受体(TLRs)mRNA的表达情况。方法分离培养小鼠骨髓来源未成熟DC。以尿酸体外刺激48 h后,RT-PCR方法检测DC TLR2 mRNA、TLR3 mRNA、TLR4 mRNA、IL-12 p70 mRNA等的表达,ELISA法检测上清IL-12 p70水平。尿酸及NF-κB抑制剂PDTC刺激不同时间点时,免疫印迹法检测DC NF-κB p65活化情况。结果尿酸刺激后DC TLRs mRNA表达出现明显的变化,与培养基对照组相比,TLR2 mRNA、TLR3 mRNA、TLR4 mRNA表达下降(P<0.05),以TLR4mRNA下降最明显;IL-12 p70表达显著增高(P<0.05);与LPS组相比,TLRs mRNA与IL-12 p70表达水平相似(P>0.05)。尿酸刺激后15～45 min,DC核因子NF-κB p65显著活化。结论尿酸能调节未成熟DC TLR2 mR-NA、TLR3 mRNA、TLR4 mRNA及IL-12 p70的表达,促进NF-κB向核内转移,促进DC成熟。TLRs mRNA的动态变化可能为其诱导DC成熟及免疫功能提高的机制之一。

Objective To investigate the expression of Toll- like receptors （TLR） mRNA in dendritic cells （DCs） after simulating with uric acid. Methods DCs were obtained from murine bone - marrow and cultured in vitro. After treatment with uric acid for 48 hours, the total RNA of DCs was extracted for assessment of mRNA of TLR2, TLR3, TLR4 and IL - 12 p70 by RT - PCR. After immature DCs were stimulated with uric acid （200μg） and NF - KB inhibitor PDTC, cytoplasmic and nuclear extracts were col[lected for immunoblot analysis of NF - KB p65 at 15, 30 and 45 min. Results The expression of mRNA of TLR2, TLR3 and TLR4 was significantly reduced in DCs treated with uric acid （P 〈 0. 05 ）, with significant increase of IL - 12 p70 mRNA （P 〈 0.05 ）. Meanwhile, there was no significant difference between the effects of uric acid and LPS stimulation on DC （P 〉 0. 05）. Increased expression of NF-κB p65 was observed in DC nuclear extract between 15 to 45 min after stimulation. Conclusion Uric acid down - regulates the mRNA expres- sion of TLR2, TLR3 and TLR4 ; up - regulates the mRNA expression of IL - 12 p70 ; and enhance NF-κB nuclear trans- portation. These may contribute to the uric acid - stimulated maturation of DCs.