Glucosamine reduces blood-brain barrier disruption by inhibiting the expression of matrix metalloproteinase-9 in experimental autoimmune encephalomyelitis rats

氨基葡萄糖对EAE大鼠BBB和MMP-9的作用(英文)

We investigated the effects of glucosamine(GS) on blood-brain barrier(BBB) function and matrix metalloproteinase-9 (MMP-9) expression in rats with experimental autoimmune encephalomyelitis(EAE).Animals were randomly divided into three groups,among which the EAE and GS groups were immunized with complete antigen and pertussis toxin,and the adjuvant group was immunized with complete Freund's adjuvant and pertussis toxin.Rats were treated by peritoneal injection of GS 180 mg/(kg·d) in the GS group and peritoneal injection of phosphate-buffered saline 4.5 mL/(kg·d) in the EAE and adjuvant groups.We proposed to assess the integrity of BBB by calculating cerebrospinal fluid to serum albumin quotient(QA) on days 6,8,10,12,14,16 and 18 post-immunization.At the same time,the brains and spinal cords were removed for MMP-9 immunohistochemical staining. Experiments demonstrated that in the EAE group,QA value and MMP-9 expression were highly elevated and up-regulated and correlated to disease severity.Moreover,there was statistically significantly positive correlation between QA value and MMP-9 expression.In the GS group,we observed that the mean disease onset date was delayed,the incidence and mean score of symptom were suppressed at the peak phase of disease(P<0.05).Furthermore,QA value and MMP-9 expression in the GS group showed stronger inhibition when compared with those of the EAE group(P<0.05).Our study showed that GS would reduce the BBB breakdown and leukocyte trafficking by inhibiting the production of MMP-9 and mitigate EAE.

本研究旨在探讨氨基葡萄糖(GS)对实验性自身免疫性脑脊髓炎(EAE)大鼠血脑屏障(BBB)功能及基质金属蛋白酶-9(MMP-9)的影响。雌性Wistar大鼠随机分为EAE组、GS组和佐剂组。EAE组和GS组用完全抗原和减毒百日咳原液免疫后腹腔分别注射4.5 mL/(kg·d)的磷酸盐缓冲液(PBS)和180 mg/(kg·d)的GS;佐剂组用完全弗氏佐剂和减毒百日咳原液免疫后腹腔注射4.5 mL/(kg·d)自PBS;免疫后(p.i.)6、8、10、12、14、16、18天检测大鼠血清和脑脊液(CSF)中白蛋白(ALB)含量,其CSF与血清ALB比值(QA)作为评价BBB功能及动态变化的指标。同时取大鼠脑和脊髓制成石蜡切片,行MMP-9免疫组化染色。结果显示,EAE组QA值和MMP-9在免疫后初期开始升高,p.i.10天达高峰,二者相关性分析显示呈显著正相关,并且其大小同临床症状的严重程度相关联。GS能明显改善EAE临床症状(P<0.05),降低EAE发病时QA值水平和中枢神经系统内MMP-9的表达(P<0.05)。我们认为GS可抑制MMP-9的生成,减轻BBB的破坏,对EAE发病起一定程度的干预作用。