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: Granulocyte colony-stimulating factor attenuates LPS-stimulated IL-1beta release via suppressed processing of proIL-1beta, whereas TNF-alpha release is inhibited on the level of proTNF-alpha formation.
    Author: Boneberg EM, Hartung T.
    Journal: Eur J Immunol; 2002 Jun; 32(6):1717-25. PubMed ID: 12115655.
    Abstract:
    In the presence of granulocyte colony-stimulating factor (G-CSF), the release of IL-1beta and TNF-alpha by LPS-stimulated human whole blood was suppressed. Via measurement of cytokine mRNA, inactive precursor and mature protein, we investigated whether this inhibition occurs at the transcriptional, translational or post-translational level of cytokine production. G-CSF inhibited IL-1beta release, but the formation of proIL-1beta was not attenuated, indicating that G-CSF interferes with the proteolytic processing of proIL-1beta. Since the release of IL-1beta in LPS-stimulated whole blood was blocked by the caspase-1 inhibitor YVAD-cmk, processing of proIL-1beta appears to depend on caspase-1 activity. The conclusion that G-CSF inhibits caspase-1 activity was supported bythe finding that the release of IL-18 was also inhibited by G-CSF, similar to IL-1beta release. Intracellular caspase-1 activity in monocytes was measured by flow cytometry with the cell-permeablecaspase substrate Asp(2)-rhodamine. In the presence of G-CSF the cleavage of this substrate was inhibited by more than 50%. G-CSF had no effect on LPS-induced doubling of caspase-1 mRNA, indicating that G-CSF affects caspase-1 activation and not its formation. For TNF-alpha another mechanism of G-CSF action was identified: TNF-alpha as well as proTNF-alpha formation were inhibited by G-CSF, butG-CSF had no influence on LPS-induced TNF-alpha mRNA level. We therefore suggest that G-CSF causes translational silencing of LPS-induced TNF-alpha mRNA.
    [Abstract] [Full Text] [Related] [New Search]