Monosodium urate induces macrophage M1 polarization and endothelial apoptosis via the HIF1A-glycolysis axis.

BACKGROUND

Monosodium urate (MSU) crystal deposition causes gout, which causes inflammation mediated by macrophages. HIF1A regulates inflammation and cellular metabolism, but its role in MSU-induced macrophage polarization and consequent endothelial dysfunction remains undefined.

METHODS

This study analyzed the public transcriptome (GSE242872) to identify key genes in MSU-stimulated mouse ankle tissue. THP-1 - derived macrophages (THP-1 - DM) and stimulated with MSU. Loss- and gain-of-function studies of HIF1A were performed using siRNA or overexpression, with or without 2-DG, a glycolysis inhibitor. Polarization markers and glycolytic effectors were assessed by qRT-PCR and Western blot. Conditioned medium (CM) from macrophages was applied to HUVECs to evaluate endothelial viability, apoptosis, and inflammation.

RESULTS

Bioinformatic screening highlighted HIF1A as a hub gene upregulated at 8 h and 24 h after MSU exposure. Experimentally, MSU drove THP-1-DM toward a pro-inflammatory M1 phenotype and suppressed M2 markers. MSU also induced HIF1A and upregulated glycolytic enzymes (PDK1, PGK1, GLUT1, GCK, PKM2). HIF1A knockdown attenuated MSU-induced M1 markers, restored M2 markers, and blunted glycolytic activation; conversely, HIF1A overexpression enhanced glycolytic enzymes and M1 polarization while inhibiting M2, effects reversed by 2-DG. CM from MSU-stimulated or HIF1A-overexpressing macrophages reduced HUVECs viability, increased apoptosis, and elevated endothelial inflammation genes, whereas CM from HIF1A-silenced cells mitigated these changes; 2-DG partially rescued HIF1A-overexpression effects.

CONCLUSION

MSU drives macrophages toward an M1 phenotype through HIF1A-dependent glycolytic reprogramming, and the resulting macrophage secretome promotes endothelial inflammation. Targeting HIF1A-mediated metabolic pathways may provide therapeutic strategies for gout-associated vascular complications.