内毒素诱导的葡萄膜炎中虹膜固有组织细胞上MyD88与TLR-4的共表达

Co-expression of TLR-4 and MyD88 in iris-resident tissue cell during endotoxin-induced uveitis

目的观察小鼠内毒素诱导的葡萄膜炎(endotoxin-induced uveitis,EIU)模型中Toll样受体-4(Toll-like receptor-4,TLR-4)、髓样分化因子88(myeloid differentiation factor 88,MyD88)、CD163的共表达。方法 6～8周龄雄性C3H/HeN(野生型)小鼠25只,C3H/HeJ(TLR-4基因缺陷型)小鼠5只,分别腹腔注射霍乱弧菌内毒素细胞壁脂多糖(lipopolysaccharide,LPS)诱导急性前葡萄膜炎动物模型,处死小鼠后虹膜、睫状体铺片,用免疫荧光三标记的方法检测虹膜、睫状体组织内不同时间CD163、TLR-4、MyD88的表达,并对虹膜内CD163、TLR-4和MyD88阳性细胞进行计数分析。结果 C3H/HeN小鼠LPS注射后12h结膜囊内出现炎症反应,24～48h达到高峰,72h炎症逐渐消退,而C3H/HeJ小鼠LPS注射后没有发现炎症反应。在内毒素诱导的C3H/HeJ小鼠虹膜中未检测到CD163、TLR-4和MyD88阳性细胞。C3H/HeN小鼠腹腔注射LPS后在虹膜铺片内0h未见CD163、TLR-4与MyD88阳性表达,12h后可见阳性细胞(40.3±8.9、45.2±6.3、42.5±4.1),24h阳性细胞数(121.0±39.5、138.6±28.3、125.5±36.1)较12h明显增多,差异均有统计学意义(均为P<0.05);48h阳性细胞数(132.3±54.5、129.9±36.2、122.1±29.3)与24h相比,差异均无统计学意义(均为P>0.05);72h阳性细胞数(12.8±3.2、10.4±5.6、9.3±5.2)较48h减少,差异均有显著统计学意义(均为P<0.01)。结论小鼠EIU模型中,LPS激活了CD163标记的巨噬细胞膜表面的TLR-4,TLR-4与MyD88途径可能是EIU主要的信号传导途径。

Objective To observe the co-expression of Toll-like receptor-4（TLR-4）,myeloid differentiation factor 88（MyD88） and cluster of differentiation 163（CD163） in endotoxin-induced uveitis（EIU） model of mouse.Methods The male C3H/HeN（wild-type） mice（25 cases） with 6 weeks to 8 weeks old and C3H/HeJ（TLR-4 gene-deficient ） mice were intraperitoneal injected of vibrio cholerae cell wall endotoxin lipopolysaccharide（LPS） to induce the acute anterior uveitis animal model,mice were sacrificed at different time points after the iris stretched,the CD163,TLR-4,MyD88 expression in iris and ciliary body tissues were detected at different time points by immunofluorescence three subject,and the CD163＋,TLR-4＋ and MyD88＋ cell in the iris were counted.Results The inflammation in C3H/HeN mice was appeared at 12 hours after LPS injection,peaked from 24 hours to 48 hours,then gradually descended at 72 hours,but no inflammation was seen in C3H/HeJ mice.No CD163＋,TLR-4＋ and MyD88＋ cell was detected in C3H/HeJ mice.In C3H/HeN mice,no CD163＋,TLR-4＋ and MyD88＋ cell was detected at 0 hour after injection,which at 12 hours after injection were 40.3±8.9,45.2±6.3 and 42.5±4.1,at 24 hours were 121.0±39.5,138.6±28.3 and 125.5±36.1,at 48 hours were 132.3±54.5,129.9±36.2 and 122.1±29.3,at 72 hours were 12.8±3.2,10.4±5.6 and 9.3±5.2,there were statistical differences between 12 hours and 24 hours（both P0.05）,significant differences between 48 hours and 72 hours（both P0.01）,but no difference was found between 24 hours and 48 hours（both P0.05）.Conclusion In EIU model,LPS activate the TLR-4 in cell surface of macrophage marked by CD163,TLR-4 and MyD88 pathway may be the major signal transduction pathway for EIU.