(1605) GJA1-20k Modulates Essential Proteomic Signatures in a Pig Model of Traumatic Hemorrhagic Shock

Introduction: Management of traumatic hemorrhagic shock is complex, involving dysregulation of several pathophysiologic processes. Beyond blood products and tranexamic acid, widely accepted treatments are scarce. We previously showed that treatment with GJA1-20k, a stress response protein upregulated after ischemia and protective against oxidative stress, reduces resuscitation requirements and renal injury in a pig model of hemorrhage and ischemia-reperfusion injury. We seek to identify proteomic signatures of GJA1-20k treatment in this model.

Methods: Twelve anesthetized pigs underwent splenectomy and were hemorrhaged of 25% their estimated blood volume followed by 45 minutes of complete supra-coeliac aortic occlusion via REBOA. Twenty-five minutes into occlusion, animals received 1-hr intravenous infusion of 0.9% saline (placebo) or GJA1-20k (0.01 mg/kg). Subsequently, autologous blood was transfused and REBOA removed. Critical care and algorithmic resuscitation commenced with isotonic crystalloids and norepinephrine. Post-euthanasia, liver samples were processed for liquid chromatography-tandem mass spectrometry. Statistical analyses within Proteome Discoverer 2.5 identified significant changes in protein expression. Using Uniprot BLAST and ALIGN, Homo sapien homologs for Sus scrofa proteins of interest were identified. Gene ontology and functional enrichment analysis (FEA) identified significant biological process terms and pathways.

Results: We found significant downregulation in 20 specific proteins and upregulation in 34 others. FEA and annotation revealed associations of upregulated protein clusters with response to oxidative stress, electron transport chain pathways, cellular response to tumor necrosis factor, interferon gamma signaling, innate immune response, and defense response to bacteria. FEA and annotation of downregulated clusters indicated associations with platelet activation signaling.

Conclusions: These results suggest that GJA1-20k directly affects specific protein pathways of particular importance after traumatic hemorrhagic shock. Further investigation of these pathways could identify new therapeutic targets and biomarkers; additionally improving our understanding of the mechanisms by which GJA1-20k affords protection against oxidative stress.