Institute of Neuroscience, Chongqing Medical University, Chongqing 400016, China.
Eur J Pharm Sci. 2011 Apr 18;42(5):540-6. doi: 10.1016/j.ejps.2011.02.009. Epub 2011 Feb 23.
Wnt/β-catenin signaling pathway plays an important role in the genesis and development of Alzheimer's disease. The study aims to investigate the effect of Curcumin on the expression of GSK-3β, β-catenin and CyclinD1 in vitro, which are tightly correlated with Wnt/β-catenin signaling pathway, and also to explore the mechanisms, which will provide a novel therapeutic intervention for treatment of Alzheimer's disease. Plasmid APPswe and BACE1-mychis were transiently co-transfected into SHSY5Y cells by Liposfectamin™2000. The cells were treated with Curcumin at 0, 1.25, 5.0, 20.0 μmol/L for 24 h, or with Curcumin at 5.0 μmol/L for 0, and 12, 24 and 48 h for time course assay. Cell lysates were collected for RT-PCR, Western blot assay and immunofluorescent staining were carried out for detecting the effect of Curcumin on the expression of GSK-3β, β-catenin and CyclinD1. RT-PCR and Western blot results showed that the expression of GSK-3β mRNA and protein significantly decreased in the transfected cells treated with Curcumin, and that the changes were in a dose and time-dependent manner (P<0.05); however, the protein expression of GSK-3β-Ser9 was increased (P<0.05). Meanwhile, the expressions of β-catenin and transcriptional factors CyclinD1 mRNA and protein increased and the changes were also in a dose and time-dependent manner (P<0.05). Immunofluorescent staining results not only confirmed the above changes, but also showed that β-catenin had translocated into the nucleus gradually with the increased dosage of Curcumin. Therefore, GSK-3β is a potential target for treatment of AD. Curcumin could activate the Wnt/β-catenin signaling pathway through inhibiting the expression of GSK-3β and inducing the expression of β-catenin and CyclinD1, which will provide a new theory for treatment of neurodegenerative diseases by Curcumin.
Wnt/β-catenin 信号通路在阿尔茨海默病的发生和发展中起着重要作用。本研究旨在探讨姜黄素对 APPswe 和 BACE1-mychis 瞬时共转染 SHSY5Y 细胞后，与 Wnt/β-catenin 信号通路密切相关的 GSK-3β、β-catenin 和 CyclinD1 表达的影响，并探讨其机制，为阿尔茨海默病的治疗提供新的治疗干预靶点。用 Lipofectamine™2000 将 APPswe 和 BACE1-mychis 质粒瞬时共转染到 SHSY5Y 细胞中。用姜黄素处理细胞，浓度分别为 0、1.25、5.0、20.0μmol/L，时间为 24h；或用 5.0μmol/L 姜黄素处理细胞，时间分别为 0、12、24、48h。收集细胞裂解液进行 RT-PCR 检测，Western blot 检测和免疫荧光染色检测姜黄素对 GSK-3β、β-catenin 和 CyclinD1 表达的影响。RT-PCR 和 Western blot 结果显示，姜黄素处理后转染细胞中 GSK-3βmRNA 和蛋白表达明显降低，且呈剂量和时间依赖性（P<0.05）；但 GSK-3β-Ser9 蛋白表达增加（P<0.05）。同时，β-catenin 和转录因子 CyclinD1 mRNA 和蛋白表达增加，变化也呈剂量和时间依赖性（P<0.05）。免疫荧光染色结果不仅证实了上述变化，还显示随着姜黄素剂量的增加，β-catenin 逐渐转位到细胞核中。因此，GSK-3β 是 AD 治疗的潜在靶点。姜黄素可能通过抑制 GSK-3β 的表达和诱导 β-catenin 和 CyclinD1 的表达，激活 Wnt/β-catenin 信号通路，为姜黄素治疗神经退行性疾病提供新的理论依据。
