Extract of Reishi Polysaccharides Induces Cytokine Expression via TLR4-Modulated Protein Kinase Signaling Pathways

Abstract

We have demonstrated that an extract of Ganoderma lucidum (Reishi or Ling-Zhi) polysaccharides (EORP) exerts immunomodulating activities by stimulating the expression of inflammatory cytokines from mouse spleen cells. Interestingly, via responding to LPS in genetic variation of murine macrophage HeNC2 and GG2EE cell lines, and using TLR4 Ab blockage in human blood-derived monocytic macrophages, we have found that the TLR4, but not complement receptor type 3, is a putative receptor of EORP, mediating the consequent immunomodulating events associated with IL-1 gene expression. Based on our studies of reactive oxygen species production, polymyxin B inhibition, and protein tyrosine kinase (PTK) activity, we ruled out the possibility of LPS contamination in EORP. We have found that EORP differentially modulates the protein kinase (PK)-mediated signal transduction pathways associated with inflammatory cytokine IL-1. In human macrophages and murine macrophage J774A.1 cells, EORP was found to up-regulate IL-1 secretion and pro-IL-1 (precursor of IL-1) as well as IL-1-converting enzyme expression. Specifically, EORP rapidly stimulates PTK-mediated phosphorylation, followed by induction of PKs and activation of MAPKs: ERK, JNK, and p38. Using PK inhibitors in the kinase activity assays, Western blot analyses and IL-1 ELISA, we have extensively examined and dissected the role of individual PK in the regulation of pro-IL-1/IL-1. Our findings establish that EORP-mediated signaling pathways are involved in the pro-IL-1/IL-1 regulation: PTK/protein kinase C/MEK1/ERK and PTK/Rac1/p21-activated kinase/p38.

Cellular and Molecular Mechanisms of Immuno-modulation by Ganoderma lucidum

“…Specifically, EORP rapidly stimulates protein tyrosine kinase-mediated phosphorylation, followed by induction of PKs and activation of MAPKs: ERK, JNK, and p38. These findings establish that the extract of Reishi polysaccharides induces cytokine expression via TLR4-modulated PK signaling pathways (19).…”

Isolating a Cytoprotective Compound fromGanoderma tsugae: Effects on Induction of Nrf-2-Related Genes in Endothelial Cells

“…32) Although these two reported polysaccharide-peptides have similar molecular weights of about 515 kDa, Gl-PP is extracted from the fruiting body and GLPG is prepared from bag-cultured mycelium. Nevertheless, the carbohydrateto-protein ratio in F5-2 is similar to the 84.4%:15.6% ratio reported for an extract of G. lucidum glycoprotein (EORP) that was prepared from the fruiting body by alkaline extraction 33) with immunomodulation activity, reported by Hsu et al 34) Recently, a novel polysaccharide-peptide with immunostimulation activity was prepared from the fruiting body of Anhui-grown G. lucidum. It had a carbohydrate-to-protein ratio of 85.2:14.8% and a molecular weight of 6.6 kDa, 35) but its monosaccharide composition was different from those reported before for the EORP and the F5-2.…”

Toward a Core Nutraceutical Program for Cancer Management

“…[66][67][68][69][70][71][72][73][74][75][76][77][78] The polysaccharides derived from Agaricus and Ganoderma mycelia-β-Dglucans with 1 → 3 and 1 → 6 linkages-have been shown to activate macrophages via toll-like receptor 4 and CD14 (the receptor system activated by lipopolysaccharides). [79][80][81] The oral efficacy of some preparations of these polysaccharides evidently reflects the fact that these are at least partially absorbable despite their high molecular weight (usually in excess of 10 kD).…”