摘要
目的观察髓鞘碱性蛋白(myelin basic protein,MBP)68-86及MBP87-99诱导实验性自身免疫性脑脊髓炎(experimentalautoimmune encephalomyelitis,EAE)大鼠模型中淀粉样前体蛋白(amyloid precursor protein,APP)及生长相关蛋白(growth-associatedprotein,GAP)-43mRNA表达及其环磷酸腺苷(cyclic adenosine monophosphate,cAMP)-蛋白激酶(protein kinase,PKA)的变化,探讨EAE大鼠发病过程中轴突损伤修复及其可能的分子机制。方法应用不同肽段的MBP68-86或MBP87-99与不完全福氏佐剂及结核杆菌混合制成抗原,皮下注射于大鼠双后足垫,建立大鼠EAE模型。观察其神经功能评分、脑组织病理变化,酶联免疫测定大鼠脑组织cAMP含量,实时荧光定量RT-PCR法测定大鼠脑组织APP、GAP-43及PKA mRNA表达。结果与MBP87-99组大鼠比较,MBP68-86所致EAE病情进展快,神经功能评分较高,炎细胞浸润重并形成袖套状改变。中剂量MBP68-86免疫大鼠第14天,脑组织GAP-43 mRNA表达较正常组明显降低(P<0.05);第28天,APP mRNA表达明显升高(P<0.05)。MBP87-99免疫大鼠第28天,APP mRNA表达较正常组和小剂量MBP68-86明显上升(P<0.05);GAP-43 mRNA表达较大、小剂量MBP68-86明显升高(P<0.05)。大、小剂量MBP68-86与MBP87-99免疫大鼠第28天,脑组织cAMP水平均较正常组明显增高(P<0.01或P<0.05),中剂量MBP68-86与MBP87-99组大鼠脑组织PKA mRNA表达明显升高(P<0.01)。结论 MBP68-86或MBP87-99均可诱导Lewis大鼠产生EAE。可引起脑组织的炎性细胞浸润、脱髓鞘及轴突损伤等,且损伤有一定的自我修复功能,其机制可能与调节cAMP-PKA信号途径有关。综合分析研究结果发现,MBP68-86中剂量(每只50μg)可作为探索EAE发病特点及药物观察的实验模型。
Objective To observe the expression of amyloid precursor protein （APP） and growth-associated protein （GAP） -43 and the change of cyclic adenosine monophosphate （cAMP） /protein kinase （PKA） in rats with experimental autoimmune encephalomyelitis （EAE） induced by myelin basic protein （MBP） 68-86 or MBP87-99. in order toexplore the repair of axonal damage and its mechanism during the pathological process of EAE. Methods The rats were immunized by subcutaneous injection in both hind footpads with antigen containing MBP68-86 or MBP87-99. incomplete Freund＇s adjuvant （IFA） and mycobacterium tuberculosis. The neurological score and the pathological changes of brain tissues were observed, the cAMP was measured by ELISA and the mRNA expression of APP, GAP-43 and PKA in brain tissues was detected by real-time quantitative RT-PCR. Results Compared with the rats in MBPs7-99 group, the progress of EAE was fast, the neurological scores were high, the inflammatory cell infiltration was severe, and even cuff-like change was found in MBP68-86 group. On the 14th day post-immunization （PI） , the mRNA expression of GAP-43 in brain tissues of rats in medium-doseMBP68-86group was down-regulated compared with normal group （P 〈 0.05）, the mRNA expression of APP was up-regulated on the 28th day PI （P 〈 0. 05 ）. On the 28th day PI, the mRNA expression of APP was significantly increased in MBPsT_99 group compared with normal group and low-dose MBP6s_s6group （P 〈 0. 05）, and the GAP-43 mRNA was also significantly increased compared with high and low-dose MBP6s_s6group （P 〈0. 05）. On the 28th day PI, the cAMP level in brain tissues significantly increased in high and low-dose MBP68-86 group and MBP87-99 group compared with normal group （P 〈 0. 01 or P 〈 0.05 ） , the PKA mRNA was also significantly increased in medium-dose MBP68-86and MBP87-99group （P 〈 0. 05 or P 〈 0. 01 ）. Conclusion The EAE can be induced by both MBP68-86and MBP87-99in Lewis rats. It was caused by inf
出处
《首都医科大学学报》
CAS
2012年第3期285-290,共6页
Journal of Capital Medical University
基金
国家自然科学基金(30873230)
北京市自然科学基金(7092014)
北京市属高等学校人才强教深化计划(PHR201008401)~~
