α_3、α_7-nAChRs缺损AD模型的建立及茶多酚的干预

AD Model of α_3、α_7 nAChRs Deficits and the Protection of EGCG

目的 建立 β -Amyloidpeptides(Aβ)诱导α3 、α7-烟碱型胆碱能受体nAChRs受体亚型缺失AD病理模型 ,探讨Aβ的毒性作用机理 ,并观察茶多酚 (EGCG)的可能干预。方法 纳摩尔Aβ慢性处理PC12细胞建立α3 、α7亚单位缺失细胞模型。用MTT比色法、AnnexinV -FITC、配体结合实验、WesternBlot、RPA法深入探讨Aβ损伤α3 、α7nAChRs亚型的机制以及EGCG的保护作用。结果 用纳摩尔浓度Aβ1-40 和Aβ2 5-3 5能明显降低PC12细胞 [12 5I]α -Bungarotoxin和 [3 H]Epibatidine结合位点数量 ,α3 、α7亚单位蛋白和mRNA水平 ,但不诱导凋亡 ,却明显抑制MTT。而预先加入 10 μMEGCG几乎完全抑制Aβ对 [3 H]epibatidine和 [12 5I]α -BTX的结合力的影响 ,可显著抑制Aβ对α3 、α7nAChRs受体亚单位蛋白的损伤。结论Aβ诱导nAChRs缺损神经细胞模型 ,是目前较理想研究AD的细胞模型 ;

Objective To set up the AD model with deficits of α 3、α 7 nAChRs induced by β-amyloid peptides(Aβ) and to study the underling mechanisms of Aβ toxicity and of the protection of EGCG against Aβ. Methods The PC12 cells were chronically treated with nanomolar Aβ. MTT reduction, Annexin V-FITC, Western Blot and RPA methods were adopted in this study. Results The results showed that the cells viability,the binding sites of epibatidine and [ 125I] α-bungarotoxin, as well as α 3, α 7subunits expression of nAChRs at protein and mRNA levels significantly decreased in dose-dependent way after being treated with Aβ,but when pretreated with EGCG, the attenuation of binding sites of epibatidine and [ 125I] α-bungarotoxin, as well as α 3, α 7subunits of nAChRs at protein level were extremely inhibited. Conclusion Recently, the nAChRs-deficient cell, induced by imposing Aβ is a ideal cell model for studying AD. EGCG shows the protection against the intoxication process.