Regulation of macrophage phenotypes via NF-κB/NLRP3 and HIF1α/p53 pathways by fuco-galactoglucan from Agrocybe aegerita.

Agrocybe aegerita polysaccharides (AAP), known for their diverse pharmacological properties, have yet to be fully understood in terms of their structure evaluation, effects and mechanisms on tumor-associated macrophages in colorectal cancer. Agrocybe aegerita polysaccharides were extracted using hot water and subsequently purified. Their structure was elucidated through methylation and nuclear magnetic resonance analyses. The impact of AAP-0.2A on macrophage polarization was assessed using flow cytometry, immunofluorescence, and ELISA. Furthermore, transcriptomics, molecular docking and western blot were employed to investigate the specific mechanisms by which AAP-0.2A influence macrophage polarization. Conditioned media were applied to CT26 cells to evaluate the effects on the proliferation and apoptosis of colorectal cancer cells. These findings demonstrate that AAP-0.2A are neutral fuco-galactoglucans that increased M1 phenotype markers of CD86, CCR7, IFN-γ while decreased M2 phenotype markers of CD206, Arg1 and IL-10. They enhance M1 macrophage polarization by activating the NF-κB/NLRP3 and HIF1A/P53 pathways. Further studies have shown that AAP-0.2A inhibit the proliferation and induce apoptosis of colorectal cancer cells, counteracting the effects of IL-4-conditioned media. These results suggested that AAP-0.2A repolarized macrophages from M2 to M1 phenotype through activating NF-κB/NLRP3 and HIF-1α/p53 pathways to inhibit the proliferation and induce apoptosis of colorectal cancer cells.