Fig. 1.

Inhibition of ATX activity promotes brown preadipocyte differentiation. A, Representative images and quantification of the effect of the ATX inhibitor HA155 (2.5 μm) or the structurally related but markedly less potent analog HA 51 (2.5 μm) on differentiation of primary BAT preadipocytes. Differentiated adipocytes were identified morphologically by lipid content, and the numbers per field were recorded (n = 20 fields). B, Real-time PCR measurement of Ucp-1 mRNA in primary BAT preadipocytes differentiated in presence of HA155, HA51, or vehicle control. Relative quantification (RQ) from each condition is shown. *, P < 0.02 (one-way ANOVA). C, Immunoblot analysis using antibodies to UCP1, β3 integrin, and β-actin (loading control) on lysates from BAT preadipocytes differentiated in presence of HA155 inhibitor or vehicle (dimethylsulfoxide). D, Real-time PCR measurement of Ucp-1 mRNA in primary BAT preadipocytes differentiated in presence of increasing doses of the ATX inhibitor PF83. *, P < 0.05 (unpaired Student's t test). D (right panel), Representative images of primary BAT preadipocytes incubated with the ATX inhibitor PF83. E, Expression of the proliferation marker Pcna in brown preadipocytes grown in the presence of LPA (5 μm), HA155 (2.5 μm), or PF83 (5 μm). F, LPA levels in conditioned medium treated with HA155 (2.5 μm) or vehicle control. *, P < 0.05 (unpaired Student's t test). Data were obtained from at least three independent experiments. Values shown are means ± sd.