白细胞介素-34在大鼠角膜移植排斥反应中的作用机制

目的　探讨白细胞介素-34（interleukin-34，IL-34）在大鼠角膜移植术后的表达情况以及在免疫排斥反应中的作用。方法　以SD大鼠为供体、Wistar大鼠为受体建立角膜移植实验模型。Wistar大鼠60只按照随机数字表法随机分为3组，B组为自体角膜移植组，C、D组行同种异体角膜移植术。另取10只为正常对照组（A组）。术后B、C组术眼滴泰利必妥眼液，D组术眼滴典必殊眼液。术后各组分别取10只大鼠判断四组角膜植片的存活情况并作生存分析。其余大鼠于术后14 d取术眼角膜植片，行组织病理学、免疫组织化学及RT-PCR检测。结果　生存分析结果提示，A组和B组角膜不发生排斥反应，D组角膜存活时间为（26.00±0.97）d，远高于C组（10.00±1.55）d（P<0.001）。HE染色结果显示，C组角膜组织各层有大量炎性细胞浸润以及新生血管形成，D组仅有少量炎性细胞、新生血管。免疫组织化学结果提示，IL-34蛋白在C组的表达量（0.089 4±0.005 6）明显高于A组（0.037 7±0.002 3）、B组（0.068 4±0.004 4）和D组（0.044 5±0.004 5）的表达量（F=145.21，P＜0.01），且主要集中在上皮层和基质层。RT-PCR结果提示，IL-34、IL-1β、TNF-α、IL-17A的mRNA 在C组角膜组织中表达水平明显高于A组、B组和D组（均为P<0.05）。结论　IL-34参与了大鼠角膜移植术后的排斥反应，而典必殊可能通过抑制IL-34的表达及相关的信号通路，延缓排斥反应的进展。

Mechanism of IL-34 in rat corneal allograft rejection

Objective　To investigate the expression of interleukin-34 (IL-34) after corneal transplantation in rats and its mechanisms of action in immune rejection.Methods　SD rats were used as donors and Wistar rats as the recipients to establish corneal transplantation experimental models.Together 60 Wistar rats were randomly divided into 3 groups according to the random number table methods，and rats in B group was transplantated with autologous cornea，while C and D groups received allogeneic corneal transplantation.Another 10 rats were collected as normal controls (A group).After B，C group was treated with postoperative Tarivid eye drops，D group was treated with TobraDex eye drops postoperatively.The survival rate of corneal grafts and survival analysis were evaluated in the 10 rats from the 4 groups，and then the corneal grafts were taken from the rest of rats at the fourteenth day after the operation for hstopathological，immunohistochemical and RT-PCR examinations.Results　Survival analysis showed that immune rejection did not occur in A and B group，and the mean survival time (MST) was (26.00±0.97) days in D group，which was much higher than that in group C［(10±1.55) days］(P<0.001).HE staining showed that there was obvious inflammatory cell infiltration and neovascularization in the corneal tissue of C group，and there were only a few inflammatory cells and neovascularization in D group.Immunohistochemistry showed that IL-34 protein expression in C group (0.089 4±0.005 6) was significantly higher than that of A group (0.037 7±0.002 3)，B group (0.068 4±0.004 4) and group D (0.044 5±0.004 5) (F=145.21，P<0.01)，and its expression was mainly located in the epithelial and stromal layer.RT-PCR showed that the expression levels of IL-34，IL-1β，IL-17A，TNF-α mRNA in corneal tissue of C group were significantly higher than those in A，B and D group (all P<0.05).Conclusion　IL-34 may involve in the rejection after corneal transplantation in rats，and TobraDex eye drops can delay the rejection by inhibiting the expression of IL-34 and related signaling pathways.