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

Search MEDLINE/PubMed


  • Title: Suppression of tumor necrosis factor alpha production by cAMP in human monocytes: dissociation with mRNA level and independent of interleukin-10.
    Author: Shames BD, McIntyre RC, Bensard DD, Pulido EJ, Selzman CH, Reznikov LL, Harken AH, Meng X.
    Journal: J Surg Res; 2001 Aug; 99(2):187-93. PubMed ID: 11469886.
    Abstract:
    BACKGROUND: Elevation of cellular cAMP inhibits lipopolysaccharide(LPS)-stimulated tumor necrosis factor alpha (TNF-alpha) production and increases the expression of interleukin (IL)-10 in mononuclear cells. TNF-alpha gene expression obligates activation of the transcription factor nuclear factor kappaB (NF-kappaB). Exogenous IL-10 inhibits NF-kappaB in monocytes and thus attenuates TNF-alpha production. We examined the role of endogenous IL-10 in the regulation of NF-kappaB activation and TNF-alpha production in human monocytes by cAMP. METHODS: Human monocytes were stimulated with Escherichia coli LPS (100 ng/ml) with and without forskolin (FSK, 50 microM) or dibutyryl cyclic AMP (dbcAMP, 100 microM). Cytokine (TNF-alpha and IL-10) release was measured by immunoassay. TNF-alpha mRNA was measured by reverse transcription polymerase chain reaction, and NF-kappaB DNA binding activity was assessed by gel mobility shift assay. RESULTS: cAMP-elevating agents inhibited LPS-stimulated TNF-alpha release (0.77 +/- 0.13 ng/10(6) cells in LPS + dbcAMP and 0.68 +/- 0.19 ng/10(6) cells in LPS + FSK, both P < 0.05 vs 1.61 +/- 0.34 ng/10(6) cells in LPS alone). Conversely, cAMP enhanced LPS-stimulated IL-10 release (100 +/- 21.5 pg/10(6) cells in LPS + dbcAMP and 110 +/- 25.2 pg/10(6) cells in LPS + FSK, both P < 0.05 vs 53.3 +/- 12.8 pg/10(6) cells in LPS alone). Neither TNF-alpha mRNA expression nor NF-kappaB activation stimulated by LPS was inhibited by the cAMP-elevating agents. Neutralization of IL-10 with a specific antibody did not attenuate the effect of cAMP-elevating agents on TNF-alpha production. CONCLUSION: The results indicate that cAMP inhibits LPS-stimulated TNF-alpha production through a posttranscriptional mechanism that is independent of endogenous IL-10.
    [Abstract] [Full Text] [Related] [New Search]