These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: TNFalpha is a potent inducer of platelet-activating factor synthesis in adipocytes but not in preadipocytes. Differential regulation by PI3K.
    Author: Gountopoulou A, Leondaritis G, Galanopoulou D, Mavri-Vavayanni M.
    Journal: Cytokine; 2008 Feb; 41(2):174-81. PubMed ID: 18180165.
    Abstract:
    Tumour necrosis factor alpha (TNFalpha) induces platelet-activating factor (PAF) synthesis in many inflammatory cells. Here, we investigate the possibility that TNFalpha stimulates PAF synthesis in rat adipocytes and preadipocytes and that phosphoinositide 3-kinase (PI3K) and extracellular signal-regulated kinase 1/2 (ERK1/2) are implicated in this process. Primary cultures were incubated with [3H]lyso-PAF and stimulated by TNFalpha in the presence or absence of wortmannin. We found that, although both cultures synthesized PAF at a similar basal rate, TNFalpha-induced PAF synthesis in adipocytes was 7-fold higher than in preadipocytes. This suggested a maturation of PAF-TNFalpha interrelationship during adipocyte differentiation. Wortmannin enhanced TNFalpha-dependent PAF synthesis in adipocytes but not in preadipocytes, indicating the negative control by PI3K in mature cells. PAF increase was due to the regulation of its biosynthesis since PAF-acetylhydrolase (PAF-AH) activity was TNFalpha- and wortmannin-independent. Our hypothesis is that PAF mediates TNFalpha inflammatory effects in both adipocytes and preadipocytes and that this pathway is enhanced during adipocyte differentiation, a mechanism which is highly active during the development of obesity.
    [Abstract] [Full Text] [Related] [New Search]