Immunoregulatory effect of Lactobacillus paracasei VL8 exopolysaccharide on RAW264.7 cells by NF-κB and MAPK pathways. (August 2022)

• Record Type: Journal Article
• Authors: Gao, Jie; Li, Qi; Liu, Yuwei; Yang, Bing; Ahmed Sadiqb, Faizan; Li, Xiyu; Mi, Si; Sang, Yaxin
• Is Part Of: Journal of functional foods. Volume 95(2022)
• Publication Date: 2022-08
• Subjects: Polysaccharide -- Lactobacillus paracasei -- RAW264.7 cells -- Immunomodulatory activity; Functional foods -- Analysis -- Periodicals; Food -- Biotechnology -- Periodicals; Nutrition -- Periodicals; 613.2
• DOI: 10.1016/j.jff.2022.105166
• Languages: English
• ISSNs: 1756-4646

Abstract

Graphical abstract: Highlights: VL8-EPS promoted the cell proliferation and upregulated the mRNA expression of proinflammatory cytokines such as IL-1β, TNF-α, IL-6 and IL-10. RAW264.7 macrophages mainly recognized polysaccharides through TLR4. VL8-EPS promoted nuclear translocation of the p65 subunit of NF-κB. VL8-EPS stimulated RAW264.7 macrophages through the upregulation of the NF-κB and MAPK signaling pathways. Abstract: This study explored the immunoregulatory mechanism of VL8-EPS, obtained from Viili. An RAW264.7 macrophage cell-line was used along with real-time quantitative PCR to evaluate the impact of VL8-EPS on mRNA expression of IL-1β, TNF-α, IL-6, IL-10, and TLR4. Moreover, western blot assay was conducted to study the signal pathway of NF-κB and MAPK. The VL8-EPS was found to upregulate the mRNA expression of these cytokines and TLR4, while it promoted protein phosphorylation of p65, IκBα, ERK1/2, and JNK. The immunofluorescence staining and inhibitor blocking experiments proved that TLR4, NF-κB, and MAPK signal pathway were involved to secrete immune-enhancing substances. In conclusion, VL8-EPS was involved to activate downstream signal pathways of NF-κB and MAPK through TLR4 identification, which caused an increase in mRNA expression and cytokines release, ultimately exerting immune regulation.