Regulation of carboxylesterase 1 (CES1) in human adipose tissue

Abstract

Carboxylesterase 1 (CES1) has recently been suggested to play a role in lipolysis. Our aim was to study the regulation of CES1 expression in human adipose tissue. In the SOS Sib Pair Study, CES1 expression was higher in obese compared with lean sisters (n=78 pairs, P=8.7x10(-18)) and brothers (n=12 pairs, P=0.048). CES1 expression was higher in subcutaneous compared with omental adipose tissue in lean (P=0.027) and obese subjects (P=0.00036), and reduced during diet-induced weight loss (n=24, weeks 8, 16, and 18 compared to baseline, P<0.0001 for all time points). CES1 expression was higher in isolated adipocytes compared with intact adipose tissue (P=0.0018) and higher in large compared with small adipocytes (P=4.1x10(-6)). Basal and stimulated lipolysis was not different in individuals with high, intermediate, and low expression of CES1. Thus, CES1 expression was linked to body fat and adipocyte fat content but not to lipolytic activity.

Fig. 1

Regulation of CES1 expression in human adipose tissue. (A) Adipose tissue CES1 expression during diet-induced weight loss measured by DNA microarray analysis (n = 24). (B) Adipose tissue CES1 expression during diet-induced weight loss measured by real-time PCR (n = 10). (C) CES1 expression in adipose tissue of obese and lean siblings (12 pairs of brothers and 78 pairs of sisters) measured by DNA microarray analysis. (D) CES1 expression in paired abdominal and omental adipose tissue samples from 5 obese and 5 lean women measured by DNA microarray analysis. (E) CES1 expression in isolated small and large adipocytes measured by real-time PCR (n = 5).

Fig. 2

Relation between CES1 expression and lipolysis in isolated adipocytes. Basal lipolysis (A), maximal noradrenaline-stimulated lipolysis (B), 8b-cAMP-mediated lipolysis (C), and 8b-cAMP + insulin-inhibited lipolysis (D) in samples with high, intermediate, and low CES1 mRNA levels measured by real-time PCR.