Abstract
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.