目的 观察淀粉样蛋白42(Aβ42)刺激BV-2小胶质细胞释放炎性介质白介素-1β(IL-1β)、白介素-10(IL-10)和一氧化氮(NO)的作用,以及对抗Aβ42抗体与人工合成抗Aβ42抗体对Aβ42刺激小胶质细胞释放炎性介质的抑制作用.方法 采集AD患者血清制备提纯抗Aβ42抗体,应用小鼠BV-2小胶质细胞作为体外细胞模型.分别用Aβ42、两种不同抗Aβ42抗体刺激细胞,分析刺激物对细胞活性的影响.将5 μoml/L Aβ42单独加入,以及分别与不同滴度的AD患者血清提纯的抗Aβ42抗体及相应滴度的人工合成抗Aβ42抗体(抗体滴度依次为5 μg/ml,1μg/ml,0.2 μg/ml)充分混合后加入体外细胞模型培养,于培养后6 h、12 h及24 h提取细胞上清液,测定IL-1β,IL-10,NO浓度.结果 Aβ42,人工合成和AD患者血清提纯的抗Aβ42抗体对BV-2细胞活性无影响,细胞存活率分别为(98.6±5.8)%,(101.9±2.8)%和(98.4±6.0)%,与正常对照组比较差异无统计学意义(F=0.407,P>0.05).Aβ42刺激BV-2细胞分泌炎性因子在12 h达高峰,IL-1β和IL-10浓度分别为(69.0±12.7)pg/ml和(24.1±4.0)pg/ml,NO浓度为(128.2±8.7)μmol/L,IL-1β和NO浓度均明显高于6 h及24 h(F=15.470,242.107;P<0.05),IL-10浓度与6 h及24 h比较差异无统计学意义(F=1.852,P>0.05).不同滴度的两种抗体均能明显抑制Aβ42刺激BV-2细胞分泌炎性因子.其中,同样是高浓度(5μg/ml)情况下,两种抗体的抑制作用差异无统计学意义(P>0.05);而抗体浓度均减低到0.2μg/ml时,AD患者血清提纯的抗Aβ42抗体对Aβ42刺激小胶质细胞释放炎性因子NO的抑制作用明显低于人工合成的抗Aβ42抗体[NO的浓度分别为(35.4±2.5)μoml/L和(19.2±3.3)μoml/L,P<0.05].结论 Aβ42存在刺激BV-2小胶质细胞释放炎性因子的作用;AD患者血清提纯的抗Aβ42抗体对Aβ42刺激小胶质细胞释放炎性介质的抑制作用下降.%Objective To observe the effect of β-amyloid42 (Aβ42) on stimulating the inflammatory factors production by BV-2 microglia, including interleukin-1β (IL-1β), IL-10 and nitric oxide (NO), and to contrast the inhibitory action of anti-Aβ42 antibody in serum of Alzheimer's patients and the artificially synthesized anti-Aβ42 antibody. Methods The anti-Aβ42 antibodies were extracted from the serum of Alzheimer's patients. And the BV-2 microglia cells in murine were cultured as in vitro cell model. The cells were stimulated by Aβ42 and the two different anti-Aβ42antibodies to analyze the impact of stimulants on the cell activity. The Aβ42 of 5 μmol/L was added to the culture separately or in mixture with each of the two different anti-Aβ42 antibodies. Each antibody was mixed with Aβ42 of 5 μmol/L at final anti-Aβ42 antibody titre of 5 μg/ml, 1 μg/ml and 0.2 μg/ml,respectively. Then clear supernatant was collected from each tube respectively at 6 h, 12 h, and 24 h after culture, and the concentrations of IL-1β, IL-10 and NO were determined. Results The Aβ42,artificially synthesized anti-Aβ42 antibody and anti-Aβ42 antibody from Alzheimer's patients had no effects on the activities of BV-2 cells, the cell survival rates were (98. 6±5.8)%, (101.9±2.8)%and (98. 4±6.0)%, with no significant differences as compared with normal control group (F=0. 407, P＞0. 05). The inflammatory factors releasing from BV-2 cells stimulated by Aβ42 reached the peak level at 12 h, the concentrations of IL-1β, IL-10 and NO were (69.0±12.7) pg/ml, (24.1 ±4. 0) pg/ml and (128. 2±8. 7) μmol/L, the concentrations of IL-1β and NO were significantly higher at 12 h than at 6 h and 24 h (F= 15. 470 and 242. 107, P＜0.05), there was no significant difference in the concentration of IL-10 among 12 h, 6 h and 24 h (F=1. 852, P＞0.05). The two different antiAβ42 antibodies of different titre remarkably inhibited Aβ42 stimulated BV-2 cells to release inflammatory factors. At high titre of 5 μg/ml, the two different antibodies showed no significant difference in the inhibitory effects (P＞0.05), while at the titre of 0. 2 μg/ml, anti-Aβ42 antibody from Alzheimer's patients showed a significantly lower inhibitory effect than artificially synthesized antibodies, the concentrations of NO were (35.4 ± 2. 5) μoml/L and ( 19. 2 ± 3.3) μoml/L,respectively (P ＜ 0.05). Conclusions The Aβ42 can stimulate BV-2 microglia cells to release inflammatory factors. Anti-Aβ42 antibody from Alzheimer's patients has a lower inhibitory effect on Aβ42 in stimulating microglia to release inflammatory factors.
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