纤维介素蛋白2（FGL-2）在大鼠角膜移植排斥反应中的作用

目的　研究纤维介素蛋白２（ｆｉｂｒｉｎｏｇｅｎ-ｌｉｋｅｐｒｏｔｅｉｎ２，ＦＧＬ-２）在大鼠角膜移植排斥反应发生发展过程中的作用及糖皮质激素对其表达的影响。方法　６０只成年雌性Ｗｉｓｔａｒ大鼠随机分为正常对照组、自体角膜移植组、同种异体角膜移植组和糖皮质激素组。正常对照组大鼠未行任何手术，自体角膜移植组、同种异体角膜移植组及糖皮质激素组均行穿透性角膜移植术。术后裂隙灯显微镜下观察术眼角膜炎性反应情况，按照Ｌａｒｋｉｎ的标准进行排斥反应评分，计算排斥反应指数，并在术后９ｄ和１４ｄ分别取眼球制备角膜组织切片，行组织病理学检查和免疫组织化学检测，观察角膜组织的炎性反应和ＦＧＬ-２在角膜组织中的表达；采用实时荧光定量ＰＣＲ法检测ＦＧＬ-２ｍＲＮＡ在大鼠角膜植片中的相对表达量。结果　术后９ｄ内各组角膜植片均出现不同程度的水肿、混浊及新生血管生长。同种异体角膜移植组大鼠平均在角膜移植术后９．８ｄ发生排斥反应并获病理学支持；自体角膜移植组和糖皮质激素组大鼠术后排斥反应计分均未达到诊断标准。免疫组织化学结果显示，不同时间点同种异体角膜移植组炎性细胞明显多于自体角膜移植组和糖皮质激素组。术后３组手术干预组角膜ＦＧＬ-２ｍＲＮＡ的表达均增加，在术后９ｄ和１４ｄ时同种异体角膜移植组均较自体角膜移植组和糖皮质激素组高，差异均有统计学意义（均为Ｐ＜０．０５）。结论　ＦＧＬ-２可能参与角膜移植免疫排斥反应，糖皮质激素可能通过降低其表达发挥抗排斥作用。

Role of FGL-2 in corneal graft rejection after allograft transplantation in rats

Objective To detect the role of fibrinogen-like protein 2 ( FGL-2 ) in development of corneal immunological rejection . and investigate the effects of glucocorticoid on FGL-2 expression. Methods Sixty clean female Wistar rats were randomized into normal control group , autologous corneal transplantation group and allogeneic corneal transplantation group, glucocorticoid transplantation group. Penetrating comeal transplantation was performed in the corneal transplantation group. The inflammatory response of the grafts was examined under the slit lamp microscope every day after operation and scored based on the criteria of Larkin. Rejection index ( RI) , mean survival time and survival rate were calculated. The histopathological examination was performed at 9 days and 14 days after surgery to evaluate the inflammatory marufestation. and the expressions of FGL-2 were assayed by immunochemistry and real-time fluorescence quantitative PCR( RT-qPCR) in the time points mentioned above. Results Severe cornea edema. a lot of inflammatory cells infiltration and new vessels in stroma were seen in allograft group, and nuld inflammatory response was found in autograft group and glucocorticoid group under the light microscope. The rejection occurred at 9. 8 days after operation in allograft group , and only mild edema, opacity and neovascularization of corneas were found at different degrees in autograft group and glucocorticoid group. Immunochemistry showed greater positive cells for FGL-2 in allogeneic group compared with autograft group and glucocorticoid group. The fold differences of FGL-2 mRNA expression rn cornea after amplification was significantly different among three groups at different time points , and the evident enhance of FGL-2 mRNA expression was revealed in allograft group compared with autograft group and glucocorticoid group at 9 days and 14 days after operation ( all P < 0. 01 ) . Conclrision FGL-2 may play role in the corneal immunological rejection, glucocorticoid may inhibit the rejection by down-regulating the expression of FGL-2.