544 Sphingosine-1-phosphate deficiency drives skin injury after Staphylococcus aureus infection

Objectives/Goals: We aim to determine whether inadequate sphingosine-1-phosphate (S1P) production in hyperglycemia is involved in deranged inflammatory response and host defense during methicillin-resistant Staphylococcus aureus (MRSA) skin infection. Methods/Study Population: Using a Phenome-Wide Association Study (PheWAS), we analyzed a disease-agnostic cohort of ~40,000 individuals to identify disease associations with SNPs in genes involved in the S1P pathway. RNA-seq data enabled comparison of key S1P-related genes in diabetic foot ulcer and non-ulcerated diabetic foot skin. For animal data, we infected euglycemic (EG) and hyperglycemic (HG) mice with MRSA and monitored infection resolution over 9 days. Biopsies were taken on days 1, 3, and 9, and S1P levels, lesion size, bacterial load, and cell death were assessed. To evaluate whether S1P can enhance clearance of dead cells/bacteria and promote healing, we treated mice with FTY720, an S1P agonist FDA-approved for multiple sclerosis Results/Anticipated Results: PheWAS analysis suggests that SGPL1 SNP rs111439207 has protective effects against MRSA infection (OR = 1.71, P = 0.0004) and type 1 diabetes (OR = 1.325,P = 0.003). The RNA-seq dataset revealed increased SGPL1 expression (an enzyme responsible for S1P degradation) in the skin of diabetic patients with foot ulcers. In animals, we show that infected HG mice develop larger lesions, higher bacterial loads, and poor abscess formation. We found a correlation between dead cell buildup and a lower ratio of ingested dead cells in the skin by macrophages of HG mice compared to EG mice. Topical S1P treatment decreased lesion size and bacterial load in HG mice. Discussion/Significance of Impact: Our data show increased expression of SGPL1 in diabetic patients. S1P deficiency during MRSA skin infection leads to tissue damage, uncontrolled bacterial growth, and poor resolution of the infection in mice. Topical treatment with S1P agonist is a promising therapeutic approach to enhance patient healing.