Effects of Pholiota nameko polysaccharide on NF-κB pathway of murine bone marrow-derived dendritic cells

Effect of ultrahigh pressure processing (UHP) on physicochemical properties, antioxidant activity and anti-inflammatory activity of insoluble dietary fiber from Pholiota nameko

The aim of this study was to evaluate the effect of ultrahigh pressure processing (UHP) of 200, 300, 400, 500, 600 and 700 MPa for 20, 40 and 30 min on physicochemical and bioactive properties of the insoluble dietary fiber Pholiota nameko (PN-IDF). The results revealed that UHP were capable of decreasing the particle size of PN-IDF and binding phenolic content. Moreover, UHP technique had an improving effect on the bioaccessible phenolic content, the water-holding capacity, the oil-holding capacity and the nitrite ion adsorption capacity. Further, UHP technique presented a promoting effect on the antioxidant activity by scavenging ABTS or DPPH free radicals and increasing reducing power, and the anti-inflammatory activity by inhibiting carrageenan-induced paw edema on PN-IDF. Overall, this study well proved that UHP technology could improve the physicochemical and functional quality of PN-IDF, which could be used as a promising green technique for functional food ingredients processing.

MicroRNA-5112 Targets IKKγ to Dampen the Inflammatory Response and Improve Clinical Symptoms in Both Bacterial Infection and DSS-Induced Colitis

Inflammation is a double-edged sword that can be induced by various PAMPs, resulting in the control of infection by invading pathogens or injuries. The inflammatory response requires strict and precise control and regulation. MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate gene expression via translational inhibition or mRNA degradation. However, the role of miRNAs in inflammation induced by flagellin (ligand of TLR5) has yet to be fully determined. In this study, we identified differentially expressed miRNAs in murine bone marrow-derived dendritic cells (BMDCs) between flagellin treatment and medium alone using miRNA microarray. We found that flagellin stimulation downregulated miR-5112 expression in BMDCs and spleen DCs in vitro and in vivo. The overexpression of miR-5112 decreased inflammatory cytokine production, accompanied by a reduction of IKKγ in flagellin-stimulated BMDCs. We demonstrated that miR-5112 could directly target IKKγ to inhibit inflammatory cytokine production. Furthermore, miR-5112 inhibited the inflammatory response induced by flagellin or Salmonella infection in vivo. Interestingly, miR-5112 could also dampen the inflammatory response and alleviate dextran sulfate sodium (DSS)-induced colitis in C57BL/6 mice. These results suggest that miR-5112 could be a novel therapeutic target for both bacterial infection and DSS-induced colitis model.

Immunomodulatory effects of polysaccharides enzymatic hydrolysis from Hericium erinaceus on the MODE-K/DCs co-culture model

The aim of this study was to explore the indirect immunomodulatory activities and its mechanism of enzymatic hydrolysis of Hericium erinaceus polysaccharides (EHEP) in the MODE-K/DCs co-culture model. According to the TEER value, transmission of phenol red and AKP activity of MODE-K cells, single model was established in order to evaluate the eligibility of MODE-K cells monolayer. Then the MODE-K/DCs co-culture model was set up and HEP and EHEP were added into the apical chamber, DCs were obtained for the expression of key surface markers, the ability of phagocytosis, the morphology, the secretion of cytokines and the production of target proteins. We found that after 21 d of culture, the MODE-K cells monolayer became intact and dense, which can be used for the MODE-K/DCs co-culture model. Under the treatment of HEP and EHEP, immature DCs become into mature DCs with the high expression of CD86 and MHCII, the low antigens up-taking, the typical morphology, the more content of IL-12 and TNF-α and the high level of TLR4, MyD88 and NF-κB proteins. However, compared with HEP, EHEP showed the better immunomodulatory activities. These findings indicated that EHEP could indirectly affect the immune function of DCs in the MODE-K/DCs co-culture model.

Structural properties and antioxidant activities of polysaccharide from fruit bodies of Pholiota nameko

A polysaccharide named PNP was extracted and purified from Pholiota nameko. The total sugar content of PNP was 95.29% and the molecular weight was 1.89 × 10³ kDa. The structural features of PNP were investigated by the combination of chemical and instrumental analysis such as UV spectrophotometer, specific rotation determination, FT-IR, methylisation analysis and Congo red. The results showed that the optical rotation of PNP was +120° and that it had a triple-helical structure. Besides, PNP was mainly composed of glucose and mannose at the molar ratio of 4.24:1.00. The backbone of PNP was composed of (1→3)-linked-Glc and (1→3)-linked-Man whereas the branches of (1→3,6)-linked- Glc, (1→3,6)-linked-Man and T- Glc. Consistenting with the results of UV-Vis spectra, FT-IR spectroscopy and ¹H NMR, indicated that PNP was a complex of polysaccharides and polyphenols. In vitro antioxidant results suggested that PNP was processed with certain scavenging capacity.