Immunomodulatory effect of APS and PSP is mediated by Ca2⁺-cAMP and TLR4/NF-κB signaling pathway in macrophage

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• 作者：Zhixue Wang^a ; Zijing Liu^b ; Lijng Zhou^a ; Tingting Long^a ; Xing Zhou^a ; Yixi Bao^a ; ^{yixibao@163.com}
• 关键词：APS ; astragalus polysaccharides ; PSP ; polysaccharopeptide ; TLR4 ; toll like receptors 4 ; NF-κB ; nuclear factor-κB ; LPS ; lipopolysaccharide ; cAMP ; cyclic adenosine monophosphate ; DAG ; diacylglycerol ; IP3 ; inositol 1 ; 4 ; 5-triphosphate ; PKC ; protein kinase C ; cGMP ; cyclic guanosinc monophosphate ; TNF-α ; tumor necrosis factor-α ; NiCl2 ; nickel chloride
• 刊名：International Journal of Biological Macromolecules
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：94
• 期：part_PA
• 页码：283-289
• 全文大小：1826 K
• 卷排序：94

文摘

This study is to investigate the role of second messengers and TLR4/NF-κB signaling pathway in the immunomodulatory activities of Astragalus polysaccharide (APS) and Polysaccharopeptide (PSP) in macrophages.MethodsRAW 264.7 macrophage cells were treated with APS, PSP, lipopolysaccharide (LPS), or NiCl2. Power-spectral method was used to detect protein kinase C (PKC) and Griess reaction to detect nitric oxide (NO). ELISA was conducted to detect cyclic adenosine monophosphate (cAMP), diglycerides (DAG), inositol 1, 4, 5-triphosphate (IP3), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Confocal laser scanning microscopy was performed to detect calcium level. qRT-PCR and Western blot was used to detect mRNA and protein expression of NF-κB.ResultsAPS and PSP significantly increased the concentrations of intracellular second messengers (NO, cAMP, DAG, IP3, Ca2+) and the activity of PKC in macrophages (p < 0.05).The intracellular NF-κB mRNA and protein levels were significantly increased in macrophages treated by APS and PSP (p < 0.05), whereas those were significantly decreased after NiCl2 incubation (p < 0.05). Similarly, the secretion of TNF-α and IL-6 were significantly decreased by the treatment of NiCl2.ConclusionOur findings strongly suggest that Ca2+-cAMP and TLR4/NF-κB signaling pathways are, at least partly, involved in APS and PSP mediated immunomodulatory activities in macrophages.