352 Macrophage regulation of inflammation in type 2 diabetes

Objectives/Goals: Type 2 diabetes is a metabolic disease characterized by non-resolving inflammation. Our objective is to investigate how macrophages contribute to this dysregulation. We hypothesize that diabetic macrophages have impaired response mechanisms and are more sensitive to metabolic flux, limiting their ability to effectively resolve inflammation. Methods/Study Population: To study this, we isolated and cultured bone marrow-derived macrophages from WT and db/db mice in vitro and stimulated them with maturation, inflammatory, and resolving cues. We also isolated human monocytes from PBMCs from patients with type 2 diabetes and age-matched healthy controls and stimulated them ex vivo and cultured them in vitro . We assessed their timeline of maturation through changes in cell surface markers, their functional inflammatory response through phenotypic marker changes and cytokine release, and their sensitivity to metabolic flux by culturing in the presence or absence of extracellular glutamine. Together, these responses can allow us to understand intrinsic defects in diabetic macrophages’ ability to regulate inflammation. Results/Anticipated Results: Notably, diabetic and healthy macrophages display distinct maturation timelines. Overall, diabetic macrophages lag behind healthy macrophages in expression of CD45 and F4/80 but eventually acquire a similar level of mature cell surface markers by day 7-8 in culture. In addition, diabetic cells have a higher proportion of Ly6Chi cells earlier in culture, cells that are generally more poised to be pro-inflammatory. Both healthy and diabetic mature macrophages displayed similar levels of inflammatory response cytokines, inflammatory gene expression changes, and phenotypic marker expression. Interestingly, stimulating these macrophages in the absence of glutamine revealed underlying impairments in their response to inflammatory and resolving cues. Discussion/Significance of Impact: Patients with diabetes suffer significant complications, such as susceptibility to infections and non-healing wounds, driven by impairments in resolution of inflammation. This research begins to explore the cell-mediated inflammatory aberrations in type 2 diabetes and may reveal targetable mechanisms to improve patient outcomes.