title: Growth hormone (GH) differentially regulates NF-kB activity in preadipocytes and macrophages: implications for GH's role in adipose tissue homeostasis in obesity.
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.
authors: National Institute of Nutrition, Hyderabad, 500007, India, pasupulati.anilkumar@gmail.com.
authors: P Anil
authors: PA
authors: Kumar
authors: P Swathi
authors: PS
authors: Chitra
authors: Chunxia
authors: C
authors: Lu
authors: J
authors: J
authors: Sobhanaditya
authors: Ram
authors: R
authors: Menon
mesh_terms: D016475:3T3 Cells; D017667:Adipocytes / Q000378:metabolism*; D000273:Adipose Tissue / Q000378:metabolism* / Q000503:physiopathology; D000818:Animals; D013006:Growth Hormone / Q000494:pharmacology*; D006706:Homeostasis; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism*; D009765:Obesity / Q000378:metabolism* / Q000503:physiopathology; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D016328:NF-kappa B; D013006:Growth Hormone