目的探讨雌二醇（E2）对去卵巢后实验性自身免疫性脑脊髓炎（EAE）大鼠的免疫抑制作用及其机制。方法制备去卵巢后10d的EAE动物模型,随机分为EAE组、E2治疗组和佐剂对照组。E2治疗组于免疫后（pi）0～8d肌注E2（250μg/kg）1次/d。观察各组在不同时间点的临床症状、血清E2浓度、血清和脑脊液中白蛋白含量比值（QA）,通过QA评定血脑屏障（BBB）的损害。在p i8、11、14、17d处死动物并取脑和脊髓,行HE和髓鞘染色;采用Western blot检测各组基质金属蛋白酶-9（MMP-9）的表达。结果 E2治疗组临床症状评分（0.46±0.62）较EAE组（2.88±1.26）降低（t=2.11,P〈0.05）;E2治疗组发病率（20%）较EAE组（80%）降低（χ2=6.24,P〈0.05）。pi 8～14dE2治疗组血清E2浓度较EAE组升高（F=1 532.63,P〈0.05）。pi 8～17dE2治疗组QA峰值低且出现时间较EAE组延迟（0.36±0.04 vs 0.18±0.03,F=26.20,P〈0.05）。E2治疗组MMP-9表达较EAE组明显下调（F=21.46,P〈0.05）。结论 E2能够有效抑制EAE,其抑制机制与E2下调MMP-9的表达进而保护BBB的结构和功能有关。
The effect of estradiol on blood brain barrier and matrix metalloproteinase-9 in Wistar rats with experimental autoimmune encephalomyelitis
Objective To study the immunosuppressive effect of estradiol（E2）and its mechanism in ovariectomized rats with experimental autoimmune encephalomyelitis（EAE）.Methods Wistar rats were randomly divided into EAE group,E2 group and complete Freund′s adjuvant（CFA）group after 10 days of ovariectomization.E2 group was injected with E2（250 μg/kg）once a day from 0 to 8 post immunization（pi）.The clinical symptom,the serum E2 level and the cerebrospinal fluld（CSF）/serum albumin ratio（QA） were observed at different times.The damage of the blood brain barrier（BBB）was evaluated by QA.The brain and spinal cords were removed on days 8,11,14,17 pi.For HE and Luxol Fast Blue staining.The expression of matrix metalloproteinase-9（MMP-9）was detected by western blot.Results When compared with EAE group（2.88±1.26）,the clinical symptom of E2 group（0.46±0.62） was statistically significantly decreased（t=2.11,P0.05）.The incidence in E2 group was statistically significantly decreased when compared with that of EAE group（20% vs 80%,χ2=6.24,P0.05）.When compared with EAE group,the serum E2 level in E2 group increased obviously on days 8 to 14 pi（F=1 532.63,P0.05）.The QA value in EAE group rapidly increased to the peak on day 8 pi,but slowly increased to the peak on day 14 pi in E2 group.The difference was statistically significant（0.36±0.04 vs 0.18±0.03,F=26.20,P0.05）.MMP-9 expressed in each group.The expression of MMP-9 detected by western blot in E2 group was statistically significantly decreased when compared with that of EAE group from 8 to 17 pi（F=21.46,P0.05）.Conclusion E2 is a potential agent to inhibit EAE effectively.The inhibiting mechanism of E2 is related to down-regulation of MMP-9,which may protect BBB from the damage of inflammation.
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