Mechanism of IL-34 in rat corneal allograft rejection / 眼科新进展

ABSTRACT

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.