Zinc-alpha2-glycoprotein, a lipid mobilizing factor, is expressed and secreted by human (SGBS) adipocytes

FEBS Lett. 2005 Jan 3;579(1):41-7. doi: 10.1016/j.febslet.2004.11.042.

Abstract

Zinc-alpha2-glycoprotein (ZAG), a lipid mobilizing factor, is expressed in mouse adipose tissue and is markedly upregulated in mice with cancer cachexia. We have explored whether ZAG is expressed and secreted by human adipocytes, using SGBS cells, and examined the regulation of ZAG expression. ZAG mRNA was detected by RT-PCR in mature human adipocytes and in SGBS cells post-, but not pre-, differentiation to adipocytes. Relative ZAG mRNA levels increased rapidly after differentiation of SGBS cells, peaking at day 8 post-induction. ZAG protein was evident in differentiated adipocytes (by day 3) and also detected in the culture medium (by day 6) post-induction. The PPARgamma agonist rosiglitazone induced a 3-fold increase in ZAG mRNA level, while TNF-alpha led to a 4-fold decrease. Human adipocytes express and secrete ZAG, with ZAG expression being regulated particularly through TNF-alpha and the PPARgamma nuclear receptor. ZAG is a novel adipokine, which may be involved in the local regulation of adipose tissue function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipocytes / chemistry
  • Adipocytes / metabolism*
  • Adiponectin
  • Adipose Tissue / metabolism
  • Cell Culture Techniques
  • Cell Differentiation / genetics
  • Dexamethasone / pharmacology
  • Gene Expression / drug effects
  • Gene Expression / genetics
  • Gene Expression Regulation
  • Humans
  • Insulin / pharmacology
  • Intercellular Signaling Peptides and Proteins / genetics
  • Intercellular Signaling Peptides and Proteins / metabolism
  • Interleukin-6 / genetics
  • Interleukin-6 / pharmacology
  • Lipopolysaccharides / pharmacology
  • Norepinephrine / pharmacology
  • PPAR gamma / agonists
  • PPAR gamma / physiology
  • Peptides / genetics
  • Peptides / metabolism*
  • RNA, Messenger / analysis
  • RNA, Messenger / metabolism
  • Rosiglitazone
  • Seminal Plasma Proteins / genetics
  • Seminal Plasma Proteins / metabolism*
  • Thiazolidinediones / pharmacology
  • Tumor Necrosis Factor-alpha / pharmacology
  • Tumor Necrosis Factor-alpha / physiology

Substances

  • Adiponectin
  • Insulin
  • Intercellular Signaling Peptides and Proteins
  • Interleukin-6
  • Lipopolysaccharides
  • PPAR gamma
  • Peptides
  • RNA, Messenger
  • Seminal Plasma Proteins
  • Thiazolidinediones
  • Tumor Necrosis Factor-alpha
  • Zn-alpha-2-glycoprotein
  • lipid mobilizing substance
  • Rosiglitazone
  • Dexamethasone
  • Norepinephrine