Immunomodulatory effect of intracellular polysaccharide from mycelia of Agaricus bitorquis (QuéL.) Sacc. Chaidam by TLR4-mediated MyD88 dependent signaling pathway

Glycolysis characteristics of intracellular polysaccharides from Agaricus bitorquis (Quél.) sacc. Chaidam and its effects on intestinal flora from different altitudes of mice in vitro fermentation

The glycolysis characteristics and effects on intestinal flora of polysaccharides from Agaricus bitorquis (Quél.) Sacc. Chaidam (ABIPs) in vitro fermentation by different altitudes of mice feces was examined, including low, medium, and high altitudes groups (LG, MG, and HG). In vitro, fermentation of ABIPs forty-eight hours resulted in a remarkable decrease in total sugar content and improvement of short-chain fatty acids (SCFAs) (mainly acetate, propionate, and butyrate), which simultaneously induced the composition of monose and uronic acids and SCFAs continuously change. Besides, ABIPs influenced the abundance and composition of the intestinal flora, generally increasing the abundance of probiotic bacteria (such as Bifidobacterium and Faecalibacterium) and decreasing the abundance of harmful bacteria (such as Phenylobacterium and Streptococcus) in all groups, with the highland biology core genus Blautia significantly enriched in LG and MG groups. It was also found that ABIPs enhanced pathways associated with biosynthesis and metabolism. In addition, correlation analysis speculated that the metabolism of SCFAs by ABIPs may be associated with genera such as Anaerostipes, Roseburia, and Weissella. ABIPs may protect organismal health by regulating hypoxic intestinal flora composition and metabolic function, and more superior fermentation performance was observed in MG compared to other groups.

A novel galactoxylan derived from Viola diffusa alleviates LPS-induced acute lung injury via antagonizing P-selectin-mediated adhesion function

Acute lung injury (ALI) greatly threatens human health worldwide. P-selectin is a potential target for the treatment of acute inflammatory diseases, and natural polysaccharides exhibit high-affinity for P-selectin. Viola diffusa, a traditional Chinese herbal, shows strong anti-inflammatory effects, but pharmacodynamic substances and underlying mechanisms are still unclear. In this study, a galactoxylan polysaccharide (VDPS) derived from Viola diffusa was isolated and characterized, evaluated the protective effect on LPS induced ALI and underlying mechanism. VDPS significantly alleviated LPS-induced pathological lung injury, and decreased the numbers of total cells and neutrophils as well as the total protein contents in the bronchoalveolar lavage fluid (BALF). Moreover, VDPS reduced proinflammatory cytokine production both in BALF and lung. Interestingly, VDPS significantly restrained the activation of NF-κB signaling in the lung of LPS-exposed mice, but it cannot inhibit LPS-induced inflammation in human pulmonary microvascular endothelial cells (HPMECs) in vitro. Additionally, VDPS disrupted neutrophil adhesion and rolling on the activated HPMECs. VDPS cannot impact the expression or cytomembrane translocation of endothelial P-selectin, but remarkably interrupt the binding of P-selectin and PSGL-1. Overall, this study demonstrated that VDPS can alleviate LPS-induced ALI via inhibiting P-selectin-dependent adhesion and recruitment of neutrophils on the activated endothelium, providing a potential treatment strategy for ALI.

The First Whole Genome Sequencing of Agaricus bitorquis and Its Metabolite Profiling

Agaricus bitorquis, an emerging wild mushroom with remarkable biological activities and a distinctive oversized mushroom shape, has gained increasing attention in recent years. Despite its status as an important resource of wild edible fungi, knowledge about this mushroom is still limited. In this study, we used the Illumina NovaSeq and Nanopore PromethION platforms to sequence, de novo assemble, and annotate the whole genome and mitochondrial genome (mitogenome) of the A. bitorquis strain BH01 isolated from Bosten Lake, Xinjiang Province, China. Using the genome-based biological information, we identified candidate genes associated with mating type and carbohydrate-active enzymes in A. bitorquis. Cluster analysis based on P450 of basidiomycetes revealed the types of P450 members of A. bitorquis. Comparative genomic, mitogenomic, and phylogenetic analyses were also performed, revealing interspecific differences and evolutionary features of A. bitorquis and A. bisporus. In addition, the molecular network of metabolites was investigated, highlighting differences in the chemical composition and content of the fruiting bodies of A. bitorquis and A. bisporus. The genome sequencing provides a comprehensive understanding and knowledge of A. bitorquis and the genus Agaricus mushrooms. This work provides valuable insights into the potential for artificial cultivation and molecular breeding of A. bitorquis, which will facilitate the development of A. bitorquis in the field of edible mushrooms and functional food manufacture.

A Se-enriched Grifola frondosa polysaccharide induces macrophage activation by TLR4-mediated MAPK signaling pathway

Se-polysaccharide (Se-GFP-22) from Se-enriched Grifola frondosa has double and cooperative activities of polysaccharide and Se. To delineate the underlying mechanism and signaling cascade involved in immune-stimulatory property of Se-GFP-22, the production of cellular mediators and key proteins in signaling pathway was examined. Results showed that Se-GFP-22 exhibited no cytotoxic and had a high capacity to promote macrophage phagocytosis, up-regulate interleukin-2 (IL-2), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and nitric oxide (NO) productions, as well as the relative messenger RNA (mRNA) expressions. In Se-GFP-22-induced macrophages, intracellular superoxide dismutase (SOD) activity was significantly increased to protect cells from oxidative injury. However, Se-GFP-22 induced macrophage activation was suppressed when the toll-like receptor 4 (TLR4) signaling pathway was blocked by a specific TLR4 inhibitor. According to the western blot analysis and the use of specific inhibitors against the mitogen-activated protein kinases (MAPK) signaling pathway, we speculated that Se-GFP-22 activated RAW264.7 macrophages through the TLR4-mediated MAPK signaling pathway. This study provides a molecular basis for the potential of Se-GFP-22 as a novel immune-stimulatory agent.

Immunomodulatory Effects of an Aqueous Extract of Black Radish on Mouse Macrophages via the TLR2/4-Mediated Signaling Pathway

Here, we determined the immunostimulatory effects of black radish (Raphanus sativus ver niger) hot water extract (BRHE) on a mouse macrophage cell line (RAW 264.7) and mouse peritoneal macrophages. We found that BRHE treatment increased cell proliferation, phagocytic activity, nitric oxide (NO) levels, cytokine production, and reactive oxygen species synthesis. Moreover, BRHE increased the expression of the following immunomodulators in RAW 264.7 cells and peritoneal macrophages: pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), iNOS, and COX-2. BRHE treatment significantly up-regulated the phosphorylation of components of the mitogen-activated protein kinase (MAPK), nuclear factor-κB (NF-κB), Akt, and STAT3 signaling pathways. Further, the effects of BRHE on macrophages were significantly diminished after the cells were treated with the TLR2 antagonist C29 or the TLR4 antagonist TAK-242. Therefore, BRHE-induced immunostimulatory phenotypes in mouse macrophages were reversed by multiple inhibitors, such as TLR antagonist, MAPK inhibitor, and Akt inhibitor indicating that BRHE induced macrophage activation through the TLR2/4-MAPK-NFκB-Akt-STAT3 signaling pathway. These results indicate that BRHE may serve as a potential immunomodulatory factor or functional food and provide the scientific basis for the comprehensive utilization and evaluation of black radish in future applications.

Structural characterization, antioxidant activity and anti-inflammatory of the phosphorylated polysaccharide from Pholiota nameko

In this study, a novel polysaccharide (SPN) was extracted by high-temperature pressure method and purified by a DEAE-52 column and a Sephadx G-100 gel column. PPN was obtained after phosphorylation of SPN. The differences of structural features, antioxidant activity, and anti-inflammatory effect of the two polysaccharides were investigated by chemical methods and RAW 264.7 cell model. SPN (Mw = 15.8 kDa) and PPN (Mw = 27.7 kDa) are an acidic polysaccharide with β-pyranose configuration, mainly containing rhamnose, mannose, glucose, arabinose, and galacose. FI-IR, NMR, and SEM spectra showed phosphorylation of SPN changed its structure. In methylation analysis, the major chains of SPN and PPN were 1,4-linked Glcp, 1,6-linked Galp, 1,2-linked Rhap, and 1.6-linked Manp with terminals of t-linked Glcp, t-linked Araf. The side chain of SPN was 1,4,6-linked Galp, 1,2,5-linked Araf, while the side chain of PPN was 1,4,6-linked Galp, 1,2,4-linked Glcp. In antioxidant activity experiments, the free radical scavenging rate of PPN was stronger than that of SPN. Also, PPN always has better anti-inflammatory on RAW 264.7 cells induced by LPS than that of SPN in same concentration, and it plays an anti-inflammatory role by inhibiting PI3K/AKT/mTOR pathway. The results indicated polysaccharide could significantly improve its antioxidant and anti-inflammatory function after phosphorylation. This study provides a potentially antioxidant and anti-inflammatory health food and drug.

Antitumor effect of a polysaccharide from Pseudostellaria heterophylla through reversing tumor-associated macrophages phenotype

Tumor-associated macrophages (TAMs), which are predominant tumor-infiltrating immune cells in the tumor microenvironment, participate in promoting the occurrence and metastasis of tumor cells. Reprogramming TAMs has become a promising immunotherapeutic approach for novel cancer treatments. In this study, a homogeneous polysaccharide (PHP-1) was obtained from Pseudostellaria heterophylla, and its antitumor and immunological activities, as well as the underlying molecular mechanisms were explored. These findings suggested that PHP-1 can switch M2 macrophages to the M1 type, thereby promoting tumor cell apoptosis in vitro. In addition, PHP-1 can modulate the TAMs phenotype, maintain the CD4⁺/CD8⁺ lymphocyte balance, and exert antitumor effects in H22 tumor-bearing mice. Mechanistically, PHP-1 is recognized by the TLR4 receptor, promotes Ca²⁺ release, and activates the NF-κB and MAPK signaling pathways to reset the M2-type macrophages. These findings indicate that PHP-1 from P. heterophylla can function as a tumor immunotherapeutic modulator.

Supramolecular structure features and immunomodulatory effects of exopolysaccharide from Paecilomyces cicadae TJJ1213 in RAW264.7 cells through NF-κB/MAPK signaling pathways

This study investigated the supramolecular structure features and immunomodulatory effects of two exopolysaccharide fractions (EPS1 and EPS2) from Paecilomyces cicada TJJ1213 in vitro. AFM images revealed that EPS1 and EPS2 displayed different morphological features at different concentrations. Congo red and XRD assay further proved that EPS1 and EPS2 mainly exhibited amorphous structure with random coil conformation in solution. Furthermore, the immunomodulatory effect of EPSs was investigated on RAW264.7 cells. Results showed that EPS1 and EPS2 could enhance the phagocytic activity and induce the NO production and could also significantly up-regulate the mRNA expression of iNOS, TNF-α, IL-6, IL-1β, IFN-γ and IL-4. Western blot assay analysis demonstrated that EPSs increased protein expression of TLR4 and the nuclear translocation of NF-κB p50/p65. Additionally, the phosphorylation levels of MAPKs proteins (p38, ERK and JNK) were also remarkably increased. Thus, EPSs could active TLR4-NF-κB/MAPKs signaling pathways to exert the immunomodulatory effect on macrophages.