Abstract 1487 Fpr2-/- mice fed alcohol had reduced hepatic expression of coagulation factors and antioxidants, as identified by proteomic analysis

Alcohol-associated liver disease (ALD) is a global healthcare problem with limited treatment options. Recently, Fpr2-/- (formyl peptide receptor 2 knockout) mice were shown to develop exacerbated alcohol-induced liver injury and inflammation, but the associated mechanisms remain elusive. Objective: To identify hepatic proteomic changes associated with exacerbated EtOH-induced liver injury in Fpr2-/- mice. Methods: A proteomic analysis was conducted on liver homogenates from WT and Fpr2-/- mice (n=3/group) that were fed either a control diet (pair-fed mice, PF) or a 5% ethanol (EtOH)-containing diet for 4 weeks followed by a single EtOH binge (5 g/kg). Liver antioxidants including Zinc (Zn) and total glutathione (GSH) were measured via colorimetric assay. Hepatic gene expression was assessed by RT qPCR analysis. Data were compared using a one-way ANOVA with a Tukey multiple comparison test. Results: There were 977 downregulated and 45 upregulated significant protein changes between Fpr2-/-EtOH and WT EtOH mice. Among the downregulated proteins in Fpr2-/-EtOH vs WT EtOH mice were the blood coagulation factors, F2 (mRNA & protein) and F9 (protein). Zn binding proteins, MT1 (protein) and MT2 (mRNA & protein), were significantly upregulated in Fpr2-/- EtOH vs WT EtOH mice. Increased expression of these Zn-binding proteins was associated with decreased free hepatic Zn in Fpr2-/- EtOH vs Fpr2-/- PF mice. Lastly, the rate limiting enzyme for glutathione synthesis, GCLC, and total liver GSH were downregulated in Fpr2-/-EtOH vs WT EtOH mice. Conclusions: These data suggest that loss of Fpr2 in the context of ALD may lead to impaired hepatic Zn and glutathione antioxidant system, contributing to oxidative stress and hepatocellular death. In addition, Fpr2-mediated regulation of F2 and F9 protein expression appears to be compromised which may contribute to ALD- induced coagulopathy. Further investigation is required to understand precisely how FPR2 impacts these processes in ALD.