Subcutaneous fat shows higher thyroid hormone receptor-alpha1 gene expression than omental fat

Obesity (Silver Spring). 2009 Dec;17(12):2134-41. doi: 10.1038/oby.2009.110. Epub 2009 Apr 9.

Abstract

The aims of this work were to evaluate thyroid hormone receptor-alpha (TR alpha), TR alpha 1, and TR alpha 2 mRNA gene expression and TR alpha 1:TR alpha 2 ratio, identified as candidate factors for explaining regional differences between human adipose tissue depots. TR alpha, TR alpha 1, and TR alpha 2 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. TR alpha gene and TR alpha 1 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 TR alpha 1:TR alpha 2 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 TR alpha and TR alpha 1 gene expression and with the TR alpha 1:TR alpha 2 ratio. In agreement with these findings, hnRNP A1:SF2 ratio was decreased by 1.39-fold (P = 0.001). TR alpha 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-alpha, their upstream regulators, and downstream effectors were differentially expressed in SC vs. omental (OM) adipose tissue. Our findings suggest that TR alpha1 could contribute to SC adipose tissue expandability in obese subjects.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipocytes / metabolism*
  • Adult
  • Female
  • Gene Expression*
  • Heterogeneous-Nuclear Ribonucleoproteins / genetics
  • Heterogeneous-Nuclear Ribonucleoproteins / metabolism
  • Humans
  • Intra-Abdominal Fat / metabolism*
  • Middle Aged
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Obesity / genetics
  • Obesity / metabolism*
  • Omentum / metabolism
  • RNA, Messenger / metabolism
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism
  • Stromal Cells / metabolism*
  • Subcutaneous Fat / metabolism*
  • Thyroid Hormone Receptors alpha / genetics
  • Thyroid Hormone Receptors alpha / metabolism*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • Heterogeneous-Nuclear Ribonucleoproteins
  • Nuclear Proteins
  • RNA, Messenger
  • RNA-Binding Proteins
  • THRSP protein, human
  • Thyroid Hormone Receptors alpha
  • Transcription Factors