The suppressive effects of gx-50 on Aβ-induced chemotactic migration of microglia

• Published in: International immunopharmacology 2014-04, Vol.19 (2), p.283-289
• Main Authors: Guo, Yubing, Shi, Shi, Tang, Maoping, Liang, Dongli, Xu, Wangjie, Wang, Lianyun, Wang, Zhaoxia, Qiao, Zhongdong
• Format: Article
• Language: English
• Subjects: Acrylamides - pharmacology; Alzheimer's disease; Amyloid beta-Peptides; Animals; Cell Survival - drug effects; Cells, Cultured; Chemotaxis; Chemotaxis - drug effects; Glycogen Synthase Kinase 3 - metabolism; Glycogen Synthase Kinase 3 beta; Microglia; Microglia - drug effects; Microglia - physiology; Peptide Fragments; Rats; Smad2 Protein - metabolism; TGF-β1-Smad2 pathway; Transforming Growth Factor beta1 - genetics; Transforming Growth Factor beta1 - metabolism; Zanthoxylum
• ISSN: 1567-5769; 1878-1705
• DOI: 10.1016/j.intimp.2014.01.025

Microglia, the main immune cells of the central nervous system (CNS), play a vital role in the development of AD. Once microglia are activated, they migrate to neuritic plaques and persistently release pro-inflammatory mediators that lead to neuroinflammation and neuronal degeneration, accelerating the progression of AD. In this study, we analyzed whether an AD candidate drug, N-[2-(3,4-dimethoxyphenyl)ethyl]-3-phenyl-acrylamide (gx-50), a compound extracted from Sichuan pepper (Zanthoxylum bungeanum), exhibited suppressive effects on the chemotactic migration of microglia induced by Aβ. At first, the effects of gx-50 on the migration of primary cultured microglia to Aβ were detected by transwell assay, and the secretion of chemokine CCL5 was measured by ELISA assay. Then, the release of TGF-β1 was detected by ELISA and quantitative real-time PCR, and the activation of the TGF-β1-Smad2 pathway was analyzed by Western blotting. The LDH assay revealed that cell viability was not affected by gx-50 at concentrations from 0.01 to 100μM; thus, combined with our previous studies, 1μM was chosen as the treatment concentration. The cell transwell measurement demonstrated that gx-50 suppressed the chemotactic migration of microglia by nearly 50% and inhibited the increase in CCL5 triggered by Aβ. Moreover, the analysis of the TGF-β1-Smad2 pathway revealed that gx-50 can antagonize Aβ-induced down-regulation of TGF-β1 at both the mRNA and protein levels and stimulate the signal pathway activation. Simultaneously, gx-50 pretreatment also significantly enhanced the phosphorylation of glycogen synthase kinase-3β (GSK-3β), which correlated closely with the migration of microglia. In conclusion, in the presence of Aβ, gx-50 pretreatment inhibited the excessive chemotactic migration of microglia. •gx-50 inhibits the Aβ-induced chemotactic migration of microglia.•gx-50 attenuates the Aβ-induced CCL5 up-regulation.•gx-50 increases the secretion of TGF-β1 and rescues the TGF-β1-Smad2 pathway.•gx-50 induces the inactivation of the inflammatory molecule GSK-3β.