The Gut Metabolite Phenylacetylglutamine Inhibits the Angiogenic Potential of Human Umbilical Vein Endothelial Cells Via the β-Adrenergic Receptor-LDHA Axis.

Elevated PAGln impaired blood flow recovery in a murine hindlimb ischemia model.

• A murine hindlimb ischemia model was used to assess perfusion recovery.
• PAGln treatment resulted in impaired blood flow recovery compared to controls.
• The β-receptor blocker zenidolol was able to reverse the adverse effects of PAGln on perfusion recovery.
• Lentiviral LDHA overexpression was performed in vivo to assess rescue of PAGln-induced impairment.

PAGln inhibited HUVEC proliferation, migration, and tube formation in vitro.

• Human umbilical vein endothelial cell (HUVEC) proliferation, migration, and tube formation were evaluated in vitro.
• Elevated PAGln suppressed all three measures of angiogenic potential in HUVECs.
• The β-receptor blocker zenidolol was able to reverse the adverse effects of PAGln on HUVEC angiogenic functions.
• LDHA overexpression rescued PAGln-induced angiogenic impairment in vitro.

PAGln downregulated glycolytic pathways in HUVECs.

• Gene set enrichment analysis (GSEA) was performed for pathway enrichment analyses and identified downregulation of glycolytic pathways.
• PAGln reduced proton efflux, indicating suppressed glycolytic flux.
• Glycolytic flux and enzyme expression were measured to characterize the metabolic effects of PAGln.
• PAGln suppressed LDHA expression and reduced lactate production in HUVECs.

LDHA overexpression rescued PAGln-induced angiogenic impairment both in vitro and in vivo.

• Lentiviral LDHA overexpression was performed both in vitro and in vivo.
• Rescue of angiogenic impairment by LDHA overexpression supports LDHA as a downstream mediator of PAGln's anti-angiogenic effects.
• PAGln suppressed LDHA expression and lactate production, which were reversed by lentiviral LDHA overexpression.
• These findings implicate the β-adrenergic receptor–LDHA axis as the mechanistic pathway through which PAGln inhibits angiogenesis.

The β-adrenergic receptor mediates PAGln's inhibitory effects on angiogenesis.

• The β-receptor blocker zenidolol reversed the adverse effects of PAGln on HUVEC proliferation, migration, tube formation, and blood flow recovery.
• PAGln is described as acting via β-receptors to subsequently inhibit LDHA expression.
• The mechanistic axis identified is described as the β-adrenergic receptor–LDHA axis.
• PAGln is a gut microbiota-derived metabolite previously associated with enhanced thrombosis, and this study extends its relevance to endothelial function and angiogenesis.