β淀粉样蛋白与氧应激的相互作用及PACAP-27对氧应激损伤的保护作用  

RELATIONSHIP BETWEEN AMYLOID β-PROTEIN AND OXIDATIVE STRESS AND THE PROTECTIVE ROLE OF PITUITARY ADENYLATE CYCLASE ACTIVATING POLYPEPTIDE AGAINST OXIDATIVE STRESS INDUCED DAMAGE ON NEURO-2a CELLS

作　　者：桂兰润[1] 张炳烈[2] 房征宇[2] 李文彬[2] 

机构地区：[1]北京军医学院病原室,北京100071 [2]解放军总医院老年医学研究所,北京100853

出　　处：《中国应用生理学杂志》2003年第2期171-174,共4页Chinese Journal of Applied Physiology

摘　　要：目的 :探讨 β淀粉样蛋白 (Aβ)与氧应激损伤的相互关系及脑下垂体腺苷环化酶激活多肽 2 7(PACAP 2 7)对抗氧应激致神经瘤细胞损伤的作用机理。方法 :体外培养第 15 0代Neuro 2a细胞 ,MTT法检测细胞存活率 ,Heochest332 5 8特异细胞核染色观察凋亡小体 ,提取基因组DNA鉴定细胞死亡方式及基因组内小片段含量。结果 :过氧化氢 (H2 O2 )处理接种 2 4h的Neuro 2a细胞 2 4h后 ,浓度相关地使细胞存活率下降 ,10mol·L-1时有明显的凋亡特征出现 ;与 2 5mol·L-1的Aβ2 5-35共同处理 2 4h可以使H2 O2 损伤神经元的ED50 降低至 1/10 ;PACAP 2 7( 0 .1(mol·L-1,1d加药 1次 ,共 2次 )对H2 O2 所致的细胞损伤有显著的保护作用 ,可以提高细胞的存活率 ,降低基因组小片段DNA的含量 ;PACAP受体拮抗剂PACAP 6 2 7( 10 0mol·L-1,与PACAP同时加药 )不能拮抗PACAP 2 7的保护作用。结论 :氧应激与Aβ在神经毒性方面有协同作用 ;PACAP参与对抗H2 O2 的神经毒性时 ,不通过受体激活。To observe the relationship between amyloid β-protein (Aβ) and oxidative stress and the protective role of pituitary adenylate cyclase activating polypeptide (PACAP, PACAP-27) against damage induced by oxidative stress(H 2O 2) in neuro-2a cells. Methods: With cultured neuro-2a cells the cell survival and apoptosis were measured by MTT assay, Hoechest33258 staining, DNA ladder and the percentage of small DNA fragment. Results: Concentration-dependent toxicity was induced with H 2O 2 treatment for 24 h. The neurotoxicity of H 2O 2 was increased by about 10 times with cotreatment neurons with amyloid β-protein fragment 25-35 (Aβ 25-35 ). While decrease the percentage of small DNA fragmentation the cell survival was increased with co-treatment with PACAP-27(which were added to the culture everyday). The effect of PACAP was not reversed with antagonist of PACAP receptor, PACAP 6-27 . Conclusion: Aβ and H 2O 2 can promote each other's neurotoxicity. Cultured neurons were protected by PACAP27 from the neurotoxicity of H 2O 2 but not through the activation of PACAP-27 receptor.

关 键 词：Β淀粉样蛋白 过氧化氢 Neuro-2a细胞 细胞培养 凋亡 神经瘤 细胞损伤 作用机理 

分 类 号：R338[医药卫生—人体生理学]