Growth hormone (GH) differentially regulates NF-kB activity in preadipocytes and macrophages: implications for GH's role in adipose tissue homeostasis in obesity

J Physiol Biochem. 2014 Jun;70(2):433-40. doi: 10.1007/s13105-014-0321-8. Epub 2014 Feb 15.

Abstract

Adipose tissue remodeling in obesity involves macrophage infiltration and chronic inflammation. NF-kB-mediated chronic inflammation of the adipose tissue is directly implicated in obesity-associated insulin resistance. We have investigated the effect of growth hormone (GH) on NF-kB activity in preadipocytes (3T3-F442A) and macrophages (J774A.1). Our studies indicate that whereas GH increases NF-kB activity in preadipocytes, it decreases NF-kB activity in macrophages. This differential response of NF-kB activity to GH correlates with the GH-dependent expression of a cadre of NF-kB-activated cytokines in these two cell types. Activation of NF-kB by GH in preadipocytes heightens inflammatory response by stimulating production of multiple cytokines including TNF-α, IL-6, and MCP-1, the mediators of both local and systemic insulin resistance and chemokines that recruit macrophages. Our studies also suggest differential regulation of miR132 and SIRT1 expression as a mechanism underlying the observed variance in GH-dependent NF-kB activity and altered cytokine profile in preadipocytes and macrophages. These findings further our understanding of the complex actions of GH on adipocytes and insulin sensitivity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3 Cells
  • Adipocytes / metabolism*
  • Adipose Tissue / metabolism*
  • Adipose Tissue / physiopathology
  • Animals
  • Growth Hormone / pharmacology*
  • Homeostasis*
  • Macrophages / metabolism*
  • Mice
  • NF-kappa B / metabolism*
  • Obesity / metabolism*
  • Obesity / physiopathology
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • NF-kappa B
  • Growth Hormone