Title : Macrophage-derived GAA alleviates pancreatic necrosis by enhancing efferocytosis via the uPA/uPAR pathway
Abstract:
Objectives: This study aimed to clarify GAA metabolism changes in macrophages during AP, explore its mechanism in alleviating pancreatic necrosis via regulating efferocytosis, and identify novel therapeutic targets.
Materials and Methods: Using single-cell and transcriptomic sequencing in an AP model, we screened key regulatory proteins. LPS-stimulated BMDMs established an in vitro model, with q-PCR, WB, and LC-MS validating key protein/metabolite changes. GAA’s role in efferocytosis was assessed via co-culture with apoptotic Jurkat cells. Urokinase-type plasminogen activator (uPA) was identified as a potential GAA target through database integration, with direct binding validated. In a caerulein-induced AP mouse model, we assessed the in vivo therapeutic efficacy of targeting GAA and uPA, as well as the level of in situ efferocytosis in pancreatic tissue.
Results: Through multi-omics analysis and experimental validation, this study first revealed a defect in GAA metabolism in macrophages during AP, characterized by a significant downregulation of the key synthase GATM and its downstream metabolite GAA. Functionally, exogenous supplementation with GAA effectively promoted macrophage efferocytosis in both in vivo and in vitro models, thereby significantly ameliorating pancreatic necrosis in AP. Mechanistically, we screened and identified uPA as a direct binding target of GAA. Furthermore, Co-IP revealed that GAA mediates efferocytosis by binding to uPA and competitively inhibiting its interaction with its receptor uPAR, constituting the core mechanism for its therapeutic effect on pancreatic necrosis in AP.
Conclusion: This study first reveals macrophage-derived GAA metabolism protects against AP pancreatic necrosis via efferocytosis, offering new insights into AP mechanisms and a potential therapeutic target.
