Oleic acid differentially affects lipid droplet storage of synthesized lipids in hepatocytes and adipocytes

Lipogenesis is a vital but often dysregulated metabolic pathway. Here we use optical photothermal infrared imaging to quantify lipogenesis rates of isotopically labelled oleic acid and glucose concomitantly in live cells. In hepatocytes, but not adipocytes, we find that oleic acid feeding at 60 μM increases the number and size of lipid droplets (LDs) while simultaneously inhibiting storage of de novo synthesized lipids in LDs. Our results demonstrate alternate regulation of lipogenesis between cell types. This work introduces a multiplexed sub-micron vibrational imaging technique to monitor differential effects of oleic acid in adipocytes and hepatocytes.