Poster #073, University of California, Riverside
Generating 3D adipose organoids from obese male and female mice and co-culture with macrophages to determine sex-dependent immune regulation of obesity
Mentors: Amber Keith, BS; PI: Meera G. Nair, PhD
Obesity continues to be a global health concern, characterized by chronic low-grade inflammation leading to comorbidities such as Type 2 diabetes and heart disease. Compared to obese females, obese males carry higher risks for cardiometabolic disorders. Studying diet-induced obese mice has been one approach in modeling these mechanistic sex differences. Resistin-like molecule α (RELMα), a protein mainly secreted from M2 macrophages and involved in downregulating inflammation, has been identified to protect high-fat diet (HFD) female mice from obesity and inflammation. Additionally, there are sex-specific differences in stromal vascular fraction (SVF) cell populations rich in mesenchymal stem cells and adipocyte precursors. To investigate if SVF stem cells differ in adipogenic potential, we generated 3D adipose organoids to measure lipid accumulation and growth between sexes before testing the influence of macrophage-derived RELMα on adipose development. SVF was obtained by harvesting visceral fat from high-fat or control diet mice that had endogenous levels of RELMα or were genetically deficient in RELMα. The SVF from each mouse was expanded for 3-5 days before plating in ultra-low attachment plates to form spheroids in a scaffold-free environment, and was provided with factors to induce adipogenesis. The organoids were also placed in different conditioned media (causing no expression or overexpression of RELMα), simulating immunoactivity within the organoid. Once mature, organoids were stained with BODIPY to analyze lipid droplets. We hypothesize that analysis will reveal greater lipid accumulation and organoid size in HFD male organoids than in female organoids. Additionally, we predict that organoids in media enriched with RELMα will exhibit reduced lipid accumulation and size compared to those that are not. Such results would be particularly insightful for solidifying our understanding of RELMα’s specific effects on lipid accumulation between sexes. They could prove crucial in innovating more effective immune therapies for obesity.