托法替尼对大鼠实验性自身免疫性脑脊髓炎的抑制作用及其机制

Effect and Mechanism of Tofacitinib on Experimental Autoimmune Encephalomyelitis in Rats

目的探讨托法替尼对模型大鼠实验性自身免疫性脑脊髓炎(EAE)的抑制作用及其机制。方法将50只Wistar雌性大鼠随机分为正常对照组,模型对照组,托法替尼小、中、大剂量组,每组10只。除正常对照组外,其他各组采用髓鞘碱性蛋白(MBP)及完全弗氏佐剂制备EAE模型。从造模前3 d开始,正常对照组与模型对照组给予0.9%氯化钠溶液灌胃,托法替尼小、中、大剂量组分别给予托法替尼1,2,4 mg·kg^-1·d^-1灌胃,连续10 d。观察各组大鼠发病情况,记录大鼠发病潜伏期、进展期及发病高峰期神经功能障碍评分(NDS)。于发病高峰期处死大鼠,未发病大鼠饲养8周后处死,取脑组织。采用苏木精-伊红(HE)染色法观察脑组织病理改变;免疫组化法检测各组大鼠脑白质脱髓鞘及星型胶质细胞活化情况。结果与模型对照组比较,托法替尼小、中、大剂量组大鼠发病潜伏期延长,进展期缩短,NDS降低,脑组织炎性细胞浸润程度减轻,MBP染色阳性表达平均吸光度值增加,胶质纤维酸性蛋白阳性细胞平均吸光度值降低(P<0.01,P<0.05);且呈剂量依赖性,剂量越大作用越明显。结论托法替尼对模型Wistar大鼠EAE具有抑制作用,且呈剂量依赖关系,其作用机制可能与减轻大鼠脑组织炎性细胞浸润、减轻脑白质脱髓病变、抑制脑组织星型胶质细胞活化有关。

Objective To investigate the inhibitory effect and mechanism of tofatinib on experimental autoimmune encephalomyelitis(EAE)in rats.Methods Totally 50 female Wistar rats were randomly assigned into normal control group,model control group,low-dose,medium-dose and high-dose tofacitinib group(10 for each group).The rats were given subcutaneous injection of the myelin basic protein of guinea pig spinal cord and complete Freund's adjuvant immunizing antigen to induce EAE model.The normal control group and model control group were fed 0.9%sodium chloride solution,and low-dose,medium-dose and high-dose tofacitinib group were given tofacitinib 1,2 and 4 mg·kg^-1·d^-1 for 10 days from 3 days before the beginning.The incubation period,progressive stage and neurological dysfunction score of the onset of the peak were recorded.Afterward,rats were executed at the peak of onset,whereas rats free of disease were executed after 8 weeks from the beginning of experiment.The pathologic changes of rat brain tissue were observed by HE staining.The degree of demyelination and active astrocytes in brain tissue were detected via immunohistochemistry.Results Compared with the model control group,the incubation period extended,progressive stage shortened,and neurological dysfunction score were deceased in tofacicitinib groups.And the inflammatory cell infiltration in brain tissue,the degree of demyelination and active astrocytes in brain tissue were deceased significantly in tofacitinib groups(P<0.01,P<0.05),The protective effect of tofatinib was in a dose-dependent manner.Conclusion Tofacitinib has inhibition effect in Wistar rats with EAE in a dose-dependent manner,and its mechanism may be related with the decrease of the inflammatory cell infiltration in brain tissue,the remission of myelinoclasis and the suppression of activation of astrocytes.