Human PTGR2 Inactivation Alters Eicosanoid Metabolism and Cytokine Response of Inflammatory Macrophages

Prostaglandin reductase 2 (PTGR2) regulates inflammatory lipid signaling through the metabolism of the PGE2 metabolite 15-keto-PGE₂. PTGR2 inhibitors have been reported but whether small molecule inactivation can recapitulate the anti-inflammatory phenotype observed in PTGR2 knockout systems has not been explored. Here, we disclose an optimized sulfonyl triazole (SuTEx) inhibitor of human PTGR2 that blocks biochemical activity by liganding the noncatalytic tyrosines Y100 and Y265 in the active site. Quantitative and multiplexed chemoproteomics verified covalent engagement of endogenous PTGR2 in THP1 macrophages with moderate proteome-wide selectivity. PTGR2 inactivation with the SuTEx inhibitor resulted in suppression of secreted inflammatory lipids and TNF-α in lipopolysaccharide (LPS)-stimulated macrophages. Collectively, our findings identify a potent covalent inhibitor of human PTGR2 that can serve as a tool compound for exploring lipid metabolism and signaling in macrophages.