Investigating Fatty Acid Uptake in Endothelial Cells Using a 3T3L1 Adipocyte Model

Fatty acids (FAs) are essential for energy storage, but disruptions to the mechanisms regulating FA transport can contribute to metabolic diseases such as diabetes. In order to get into cells, FAs must move from the bloodstream into cells like adipocytes (fat cells), passing through endothelial cells (ECs), which comprise the walls of blood vessels. Previous research has found that adipocytes release lactate, which signals ECs to increase FA uptake and transport. This process is under endocrine regulation as well, as insulin will promote FA transport into adipocytes. However, this research was conducted using isolated murine pre-adipocytes, which can be expensive and difficult to isolate, differentiate, and maintain. My research aims to replicate the aforementioned findings using the 3T3L1 adipocyte model, which is more cost-effective and easier to carry out. In this protocol, 3T3L1 fibroblast cells are first induced to differentiate into adipocytes using a chemical cocktail containing insulin, dexamethasone, and IBMX. Once differentiated, the adipocytes are treated with insulin, and the conditioned media (containing the released lactate) is collected and applied to ECs. Endothelial FA uptake is then measured using BODIPY C-12, a fluorescent FA analog. Thus far, our results show that media from insulin-treated adipocytes leads to a small but statistically significant increase in FA uptake by ECs. However, the effect was weaker than expected. In the future, we plan on optimizing the differentiation protocol and testing the role of other metabolic hormones, such as Insulin-like Growth Factor-1 (IGF-1), which may further enhance FA transport. Understanding how adipocytes regulate FA uptake in ECs is important for identifying new targets for treating metabolic disorders. If successful, this study will establish a reliable and economical model for understanding lipid transport, aiding in future research on diabetes and other related diseases.