CAJ | 학술논문

目的：探讨脑源性神经生长因子（BDNF）对抗β-淀粉样蛋白25-35的神经毒性作用是否与自噬有关，以及该自噬过程是否通过蛋白激酶 B（AKT）／哺乳动物雷帕霉素靶蛋白（mTOR）／核糖体蛋白 S6激酶（70S6K）途径调控。方法将 Aβ25-35加入不同浓度 BDNF 预处理后的 HT22细胞共孵育24 h，采用 CCK8法测细胞活力；将 Aβ25-35及加或不加 BDNF、Rapamycin、LY294002处理 HT22细胞24 h，采用蛋白免疫印迹法检测 LC3、p-AKT、p-70S6K 的表达；采用免疫荧光法检测细胞核周自噬斑点变化情况。结果BDNF 能改善细胞活力，以100 ng／ml 时最为显著（P ＜0．05）；Aβ25-35升高 LC3-Ⅱ／Ⅰ比值，降低 p-AKT、p-70S6K 的表达，并增加细胞自噬斑点数量（P 均＜0．05）；BDNF 能增强Aβ25-35诱导的自噬活动，该增强作用可被 LY294002抑制（P 均＜0．05）。结论BDNF 能对抗 Aβ25-35的神经毒性，与通过 AKT／mTOR／70S6K 途径增强 Aβ25-35诱导的 HT22细胞自噬相关。
목적：탐토뇌원성신경생장인자（BDNF）대항β-정분양단백25-35적신경독성작용시부여자서유관，이급해자서과정시부통과단백격매 B（AKT）／포유동물뢰파매소파단백（mTOR）／핵당체단백 S6격매（70S6K）도경조공。방법장 Aβ25-35가입불동농도 BDNF 예처리후적 HT22세포공부육24 h，채용 CCK8법측세포활력；장 Aβ25-35급가혹불가 BDNF、Rapamycin、LY294002처리 HT22세포24 h，채용단백면역인적법검측 LC3、p-AKT、p-70S6K 적표체；채용면역형광법검측세포핵주자서반점변화정황。결과BDNF 능개선세포활력，이100 ng／ml 시최위현저（P ＜0．05）；Aβ25-35승고 LC3-Ⅱ／Ⅰ비치，강저 p-AKT、p-70S6K 적표체，병증가세포자서반점수량（P 균＜0．05）；BDNF 능증강Aβ25-35유도적자서활동，해증강작용가피 LY294002억제（P 균＜0．05）。결론BDNF 능대항 Aβ25-35적신경독성，여통과 AKT／mTOR／70S6K 도경증강 Aβ25-35유도적 HT22세포자서상관。
Objective To investigate the correlation between neuroprotective effect of brain-derived neurotrophic factor (BDNF)against Amyloid β-proiein25-35 neurotoxicity,and validate whether the autophagy was regulated by protein kinase B (AKT) /mammalian target of rapamycin (mTOR) /ribosomal protein S6 kinase (70S6K)signaling pathway.Methods Aβ25-35 was supplemented and co-cultured with the HT22 cells pretreated with different concentrations of BDNF for 24 h.The viability of HT22 cells was evaluated by cell counting kit-8 (CCK8).The expression levels of microtubule-associated protein light chain 3 (LC3),p-AKT, p-70S6K in HT22 cells were detected by Western blot after treated with Aβ25-35 in the presence or absence of BDNF,rapamycin,LY294002 for 24 h.Immunofluorescence assay was performed to observe the changes in the LC3 puncta in the perinuclear region of HT22 cells.Results BDNF could improve HT22 cell viability,espe-cially at the concentration of 1 00 ng/ml (P <0.05).Aβ25-35 elevated the LC3-Ⅱ/Ⅰ ratio,down-regulated the expression of p-AKT and p-70S6K and increased the number of LC3 puncta in HT22 cells (all P <0.05).BD-NF enhanced the autophagy induced by Aβ25-35 ,which could be inhibited by LY294002 (both P <0.05 ). Conclusions BDNF is able to alleviate the neurotoxicity of Aβ25-35 by promoting the Aβ25-35 -induced HT22 au-tophagy via AKT/mTOR/70S6K signaling pathway.