Fatty acid composition of lipid fractions in white- and brown-like adipocytes derived from human mesenchymal stem cells.

White and brown adipocytes differ markedly in lipid composition and metabolic function. White adipocytes primarily serve as energy storage depots, whereas brown adipocytes are mitochondria-rich and specialized for thermogenesis. However, the lipidomic profiles of white-like (WLAs) and brown-like adipocytes (BLAs) differentiated from human mesenchymal stem cells (MSCs) remain incompletely characterized. Human adipose-derived MSCs were differentiated into WLAs and BLAs. Lipid fractions were isolated and analysed by gas-liquid chromatography. Fatty acid composition data were used to calculate indices of stearoyl-CoA desaturase-1 (SCD1) activity, elongation, and ω6 synthesis. Compared to MSCs, BLAs showed consistently elevated oleate (≥4.2-fold) and stearate (≥2.3-fold), along with reduced palmitate (≤-20%) and linoleate (≤-28%) across phospholipid, triglyceride, and free fatty acid fractions. WLAs versus MSCs showed similar trends, with oleate increasing up to 15-fold and palmitate decreasing by 67-82% depending on the lipid class. SCD1 activity and elongation indices were elevated in WLAs (SCD1: up to 4.7-fold; elongation: up to 28-fold). The ω6 synthesis index was also increased in triglyceride and free fatty acid fractions of WLAs (≥3.3-fold), but markedly suppressed in BLAs (≤-88.7%). WLAs and BLAs differentiated from MSCs exhibit distinct lipid profiles and inferred enzymatic activity patterns, reflecting their respective capacities for lipid storage and metabolic flexibility. These findings provide a foundation for future translational research aimed at targeting adipose tissue in obesity and metabolic diseases.