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Contradictory findings regarding the gene expression of the main lipogenic enzymes in human adipose tissue depots have been reported. In this cross-sectional study, we aimed to evaluate the mRNA expression of fatty acid synthase (FAS) and acetyl-CoA carboxilase (ACC) in omental and subcutaneous (SC) fat depots from subjects who varied widely in terms of body fat mass. FAS and ACC gene expression were evaluated by real time-PCR in 188 samples of visceral adipose tissue which were obtained during elective surgical procedures in 119 women and 69 men. Decreased sex-adjusted FAS (−59%) and ACC (−49%) mRNA were found in visceral adipose tissue from obese subjects, with and without diabetes mellitus type 2 (DM-2), compared with lean subjects (both P < 0.0001). FAS mRNA was also decreased (−40%) in fat depots from overweight subjects (P < 0.05). Indeed, FAS mRNA was significantly and positively associated with ACC gene expression (r = 0.316, P < 0.0001) and negatively with BMI (r = −0.274), waist circumference (r = −0.437), systolic blood pressure (r = −0.310), serum glucose (r = −0.277), and fasting triglycerides (r = −0.226), among others (all P < 0.0001). Similar associations were observed for ACC gene expression levels. In a representative subgroup of nonobese (n = 4) and obese women (n = 6), relative FAS gene expression levels significantly correlated (r = 0.657, P = 0.034; n = 10) with FAS protein values. FAS protein levels were also inversely correlated with blood glucose (r = −0.640, P = 0.046) and fasting triglycerides (r = −0.832, P = 0.010). In conclusion, the gene expression of the main lipogenic enzymes is downregulated in visceral adipose tissue from obese subjects. [ABSTRACT FROM AUTHOR]

The aims of this work were to evaluate thyroid hormone receptor-α (TRα), TRα1, and TRα2 mRNA gene expression and TRα1:TRα2 ratio, identified as candidate factors for explaining regional differences between human adipose tissue depots. TRα, TRα1, and TRα2 mRNA levels, and the gene expressions of arginine–serine-rich, splicing factor 2 (SF2), heterogeneous nuclear ribonucleoprotein H1 (hnRNP H1), heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1), and Spot 14 (S14) were evaluated in 76 paired adipose tissue samples obtained from a population of 38 women who varied widely in terms of obesity and body fat distribution. Gene expression for these factors was also studied in stromal-vascular cells (SVCs) and mature adipocytes (MAs) from eight paired fat depots. TRα gene and TRα1 mRNA expression were increased 1.46-fold (P = 0.006) and 1.80-fold (P < 0.0001), respectively, in subcutaneous (SC) vs. visceral fat. These differences in gene expression levels were most significant in the obese group, in which the TRα1:TRα2 ratio was 2.24-fold (P < 0.0001) higher in SC vs. visceral fat. S14 gene expression was also increased by 2.42-fold (P < 0.0001) and correlated significantly with TRα and TRα1 gene expression and with the TRα1:TRα2 ratio. In agreement with these findings, hnRNP A1:SF2 ratio was decreased by 1.39-fold (P = 0.001). TRα and S14 levels were 2.1-fold (P < 0.0001) and 112.4-fold (P < 0.0001), respectively, higher in MAs than in SVCs from both fat depots. In summary, genes for TR-α, their upstream regulators, and downstream effectors were differentially expressed in SC vs. omental (OM) adipose tissue. Our findings suggest that TRα1 could contribute to SC adipose tissue expandability in obese subjects. [ABSTRACT FROM AUTHOR]

Objective Low-grade inflammation has been related to obesity, insulin resistance and the metabolic syndrome. The Asp358Ala variant and the CA-repeat polymorphism in the interleukin-6 receptor ( IL-6R) gene have been reported to be associated with obesity in Pima Indians and Spanish women, respectively. The aim of this study was to investigate the association between these polymorphisms and obesity in a Mediterranean-Caucasian population, and to determine whether this polymorphism was related to the metabolic syndrome as defined by the National Cholesterol Education Program – Adult Treatment Panel III (NCEP/ATP-III) criteria. Design Cross-sectional. Patients Three hundred and ninety subjects from the general population. Methods The Asp358Ala and CA-repeat polymorphisms were analysed by polymerase chain reaction (PCR) amplification, followed by restriction fragment length polymorphism or capillary electrophoresis, respectively. Results Both polymorphisms were in strong linkage disequilibrium, Asp358 alleles being associated with 149 CA-repeat alleles (χ2 = 76·275, P < 0·0001). Therefore, only the association of the Asp358Ala variant with obesity and the metabolic syndrome was assessed in the whole series of subjects. Subjects homozygous for Asp358 alleles had statistically higher body mass index (BMI) compared with Ala358 carriers (27·7 ± 5·41 vs. 26·6 ± 4·96 kg/m2; P < 0·05). Moreover, the prevalence of the metabolic syndrome was significantly higher in carriers of the Asp358 allele compared with Ala358 homozygotes (12·7% vs. 0·0%; P = 0·01). This relationship remained significant after adjusting for age, insulin resistance, sex and BMI. Conclusions The Asp358Ala and CA-repeat polymorphisms in the IL-6R gene are associated with obesity and characteristics of the metabolic syndrome in our population of Mediterranean subjects. [ABSTRACT FROM AUTHOR]