Figure 8.

The eCB system directly regulates adipogenesis in cultures of adipose tissue explants, and LPS acts as a master switch both in vitro and in vivo. (A) mRNA expression levels of the adipocyte differentiation markers PPAR-γ, aP2 and C/EBP-α; (B) mRNA expression levels of the lipogenesis markers SREBP-1c and FAS and (C) mRNA expression levels of CB₁ in cultured adipose tissue explants exposed to vehicle (CT), LPS or cannabinoid receptor agonist HU-210 (HU) (100 nM) alone or in combination with LPS (100 ng/ml) for 24 h. (D) mRNA levels of the adipocyte differentiation markers PPAR-γ, aP2 and C/EBP-α and the lipogenesis markers SREBP-1c, ACC and FAS in lean wild-type mice chronically infused with cannabinoid receptor agonist (HU) (100 μg/kg/day) with or without the addition of LPS (HU-LPS) (300 μg/kg/day) through mini-pumps implanted subcutaneously for 4 weeks (n=7). (E) mRNA levels of an adipocyte differentiation marker (aP2), (F) a lipogenesis marker (FAS) and (G) CB₁ measured in cultured adipose tissue explants exposed to a PPAR-γ agonist (troglitazone, TZD) (10 μM) alone or in combination with LPS for 24 h. The data are the mean of four to five different determinations from 25 pooled mouse adipose depots. ^*Indicates P<0.05 for the drug effect; # indicates P<0.05 for the effects of LPS; and +indicates P<0.07 by a two-tailed, Student's t-test.