Astragalus Polysaccharide Promotes NLRP3Macrophages Polarization via Suppression of OGT in Hepatocellular Carcinoma.

Abstract

BACKGROUND: Hepatocellular carcinoma (HCC) is characterized by an immunosuppressive tumor microenvironment (TME) dominated by tumor-associated macrophages (TAMs). Astragalus polysaccharide (APS) exhibits anti-tumor activity, its mechanism in reprogramming immunosuppressive TAMs remains unclear. METHODS: We established a subcutaneous HCC tumor model in C57BL/6 mice and administered APS. Single-cell RNA sequencing (scRNA-seq) was performed to profile immune cell landscapes in HCC TME. Flow cytometry, immunofluorescence, and functional assays were employed to explore the role of O-linked N-acetylglucosamine transferase (OGT) in APS-mediated TME reprogramming. RESULTS: APS significantly inhibited tumor growth and remodeled the TME cellular composition. ScRNA-seq revealed 10 cell types in HCC mice tumor tissue. APS increased neutrophils, macrophages, and mast cells while reducing other immune populations. Macrophages were subclassified into C1QCTAM, NLRP3TAM, and S100A9TAM. APS specifically elevated NLRP3TAM abundance, which positively correlated with M1-like pro-inflammatory phenotypes (TNFα, complement pathway activation). Mechanistically, APS downregulated OGT expression and global O-GlcNAcylation in TAMs, promoting NLRP3TAM polarization. NLRP3TAMs with APS treatment secreted pro-inflammatory cytokines and chemokines (IL-6, IL-1B, TNFα, and CXCL10), enhancing CD8T-cell infiltration and reducing T-cell exhaustion. CONCLUSION: APS suppresses HCC by inhibiting OGT-mediated O-GlcNAcylation and promoting NLRP3M1-like TAMs enrichment, thereby enhancing anti-tumor immunity, highlighting APS as a potential immunomodulatory agent for HCC therapy.