Figure 3. Adult human neck BAT expresses functional genes similar to mouse interscapular BAT, can be grown ex vivo from multiple adipose tissue depots, and has an unstimulated energy expenditure similar to that of mouse interscapular BAT.

(a) Gene expression of BAT- and WAT-associated genes was measured in five different mouse adipose tissue depots taken from five C57Bl/6 male mice, 12 weeks-old. Clustering of the genes from the mouse depots was done with the samples of human deep neck fat that had the highest expression of UCP1, along with their associated subcutaneous fat. The heat map represents the relative abundance of each gene across all 31 samples. The values were normalized within each row using a linear color scale. The highest value in each row is colored bright red; the lowest is colored bright blue; those near the midpoint between these values are colored black. Missing values are colored gray. (b) Preadipocytes from the stromal vascular fraction of both superficial and deep neck adipose tissue fat depots from four individuals (eight different sites in total), were differentiated into mature adipocytes and then treated for 4 hours with 500 μM dibutyryl-cAMP (DB-cAMP) or vehicle. Shown is the fold increase in expression of four different BAT-associated genes, UCP1, PPARGC1A, DIO2, and PRDM16, compared to treatment with vehicle for the same duration. *, P < 0.05; errors bars are s.e.m. (c) Adipose tissue from mouse interscapular BAT or human cervical adipose tissue from four individuals’ subcutaneous (SQ) and longus colli (LC) depots. Labeling is as follows: “m” or “h” for mouse and human, respectively; neck fat depot; and number referring to the particular individual. *, P < 0.05; errors bars are s.e.m.