寡聚态β淀粉样蛋白加剧小胶质细胞衰老  

Oligomeric amyloid-βaccelerated microglia senescence

作　　者：魏振 崔晓丽 陈晓春[3] 潘晓东[3] WEI Zhen;CUI Xiaoli;CHEN Xiaochun(Department of Neurology,Fujian Provincial Hospital,Fuzhou 350001,China)

机构地区：[1]福建省立医院神经内科,福建福州350001 [2]福建中医药大学附属人民医院老年病科,福建福州350004 [3]福建医科大学附属协和医院神经内科,福建省老年医学研究所,福建省分子神经病学重点实验室,福建福州350001

出　　处：《中风与神经疾病杂志》2020年第8期680-684,共5页Journal of Apoplexy and Nervous Diseases

基　　金：国家自然科学基金面上项目(No.81571257):福建省卫计委中青年骨干课题(No.2017-ZQN-22)。

摘　　要：目的观察小胶质细胞体内外自发衰老现象,探讨β淀粉样蛋白对小胶质细胞体外衰老影响。方法Iba-1免疫组织化学法观察年轻和老年小鼠大脑皮质小胶质细胞形态学变化,通过衰老相关β-半乳糖苷酶(SA-β-GAL)染色法观察小胶质细胞衰老现象;原代培养纯化小胶质细胞,观察体外不同培养时间小胶质细胞自发衰老指标SA-β-GAL染色变化。用不同浓度寡聚态Aβ(oligomeric Aβ,oAβ)诱导处理小胶质细胞不同时间后,检测小胶质细胞SA-β-GAL表达,通过γH2AX免疫细胞化学染色检测DNA损伤标记物表达变化。结果在体老年鼠可出现小胶质细胞衰老表型;一定时间范围内小胶质细胞体外培养越长,SA-β-GAL染色阳性率越高(P<0.001),显示增龄性衰老变化。与对照组相比,oAβ处理组小胶质细胞SA-β-GAL染色阳性率增加(P<0.05)。同时,处理组小胶质细胞γH2AX表达明显上调(P<0.05)。结论小胶质细胞体内体外存在自发衰老现象,oAβ诱导并加剧小胶质细胞衰老可能与增加DNA损伤有关。Objective To observe the phenomenon of microglia senescence in vivo and in vitro,and to investigate the effect of amyloid on microglia senescence.Methods Iba-1 immunohistochemical method and senescence-associatedβ-galactosidase(SA-β-GAL)double staining in the cortex region of brains from young and aged mice was performed for visualizing microglial senescent phenotypes.Purified primary microglia cells were used to observed spontaneous senescence markers at different cultured time point in vitro.Various concentrations of oligomeric Aβ(oAβ)(1-42)were applied to primary microglia cultureto simulate the manifestation.SA-β-GAL staining was used to evaluate the degree of cellular senescence and DNA damage response was explored byγH2AX immunocytochemistry staining.Results Microglia in the aged mouse exhibited aberrant morphological and senescent phenotypes.The increasing rate of SA-β-GAL positive microglia cells was found with the prolongation of culture time in vitro(P<0.001).Compared with the control group,the positive rate of SA-β-GAL staining of microglia cells was increased in the oAβtreatment group(P<0.05).At the same time,the expression ofγH2AX was upregulated in the oAβtreated microglial cells(P<0.05).Conclusion These results implied that microglia existed spontaneous senescence phenomenon both in vivo and in vitro,which was contributed to aggravate the pathological aging by oAβ1-42 in primary microglia via the underlying mechanisms of DNA damage response.

关 键 词：Β淀粉样蛋白 小胶质细胞 细胞衰老 阿尔茨海默病 

分 类 号：R749.1[医药卫生—神经病学与精神病学]