Polysaccharide of Dendrobium huoshanense activates macrophages via toll-like receptor 4-mediated signaling pathways. (1st August 2016)

• Record Type: Journal Article
• Authors: Xie, Song-Zi; Hao, Ran; Zha, Xue-Qiang; Pan, Li-Hua; Liu, Jian; Luo, Jian-Ping
• Is Part Of: Carbohydrate polymers. Volume 146(2016)
• Page Start: 292
• Page End: 300
• Publication Date: 2016-08-01
• Subjects: Dendrobium huoshanense -- Polysaccharide -- Macrophage -- Toll-like receptor 4 -- Signaling pathway; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2016.03.059
• Languages: English
• ISSNs: 0144-8617

Abstract

Highlights: Dendrobium huoshanense polysaccharide (DHP) possesses immunostimulatory activity. TLR4 was observed to be the pattern recognition receptor (PRR) of DHP. DHP activates macrophages via TLR4-mediated signaling pathways. Abstract: The present work aimed at investigating the pattern recognition receptor (PRR) and immunostimulatory mechanism of a purified Dendrobium huoshanense polysaccharide (DHP). We found that DHP could bind to the surface of macrophages and stimulate macrophages to secrete NO, TNF-α and IL-1β. To unravel the mechanism for the binding of DHP to macrophages, flow cytometry, confocal laser-scanning microscopy, affinity electrophoresis, SDS-PAGE and western blotting were employed to verify the type of PRR responsible for the recognition of DHP by RAW264.7 macrophages and peritoneal macrophages of C3H/HeN and C3H/HeJ macrophages. Results showed that toll-like receptor 4 (TLR4) was an essential receptor for macrophages to directly bind DHP. Further, the phosphorylation of ERK, JNK, Akt and p38 were observed to be time-dependently promoted by DHP, as well as the nuclear translocation of NF-κB p65. These results suggest that DHP activates macrophages via its direct binding to TLR4 to trigger TLR4 signaling pathways.