0027FATP1 Mediates Rapid 20-HETE/GPR75-Associated Fatty-Acid Uptake in Adipocytes: Implications for Cardiometabolic Disease

Background Obesity, type 2 diabetes, MASH, and cardiovascular disease share dysregulated lipid handling in metabolic tissues. The lipid mediator 20-HETE is implicated in vascular dysfunction, hypertension, and cardiovascular disease through GPR75 signaling, while human loss-of-function variants in GPR75 protect against obesity. However, the adipocyte mechanism linking 20-HETE/GPR75 signaling to lipid accumulation remains incompletely defined. We asked whether FATP1/SLC27A1, an adipocyte-enriched fatty-acid transporter, mediates the downstream uptake step in mature adipocytes. Methods Murine 3T3-L1 cells were differentiated into mature adipocytes over 10 days. Intracellular Ca²⁺ flux was measured using FLIPR Calcium 6 dye after stimulation with 20-HETE (10 nM) or vehicle. Fatty- acid uptake was quantified using a fluorescence-based uptake assay. To assess transporter involvement, mature adipocytes were pretreated with FATP1-IN-1 (FATP1 inhibitor) or sulfosuccinimidyl oleate (SSO, CD36 inhibitor) before 20-HETE stimulation. Results 20-HETE induced a rapid Ca²⁺ transient in mature Day 10 adipocytes, followed within minutes by increased fatty-acid uptake; both responses were minimal in Day 0 preadipocytes. FATP1-IN-1 did not suppress the proximal Ca²⁺ response but abolished 20-HETE-induced fatty-acid uptake, implicating FATP1 as the dominant transporter mediating the acute uptake step. In contrast, SSO did not suppress peak uptake and increased early uptake/AUC, suggesting that CD36 is not the primary transporter for this response and may play a modulatory role. Conclusions These findings identify FATP1 as the adipocyte transporter arm of a rapid peripheral 20-HETE/GPR75/Ca²⁺-associated lipid-uptake pathway. We propose a novel feed-forward adipocytelipid-burden model in which lipid overload increases 20-HETE/GPR75 signaling, promoting FATP1-dependent fatty-acid uptake and further metabolic dysfunction. Is this an encore abstract? No