Please use this identifier to cite or link to this item: https://repositorio.ucb.br:9443/jspui/handle/123456789/7425
metadata.dc.type: Artigo
Title: Activation of the CAMP Cascade Inhibits an Early Event Involved in Murine Macrophage Ia Expression
Authors: Figueiredo, Florêncio
Uhing, Ronald J.
Kenji, Okonogi
Gettys, Tom W.
Johnson, Stewart P.
Adams, Dolph O
Prpic, Verônica
Abstract: The ability of interferon-gamma (IFN gamma) to increase class II major histocompatibility complex (class II MHC) gene products in murine macrophages involves activation of Na+/H+ exchange (Prpic V., Yu, S. F., Figueiredo, F., Hollenbach, P. W., Gawdi, G., Herman, B., Uhing, R. J., and Adams, D. O. (1989) Science 244, 469-471). The ability of IFN gamma to increase class II MHC gene product expression is inhibited by a variety of agents. In the present studies, the involvement of cAMP-dependent protein kinase in modulating IFN gamma-induced expression of MHC gene products and the mechanism of regulation were assessed in macrophages treated with agents which activated cAMP-dependent protein kinase by different molecular mechanisms. Prostaglandin E2 (PGE2) produced a rapid (within 30 s) dose-dependent elevation of cAMP which was paralleled by the activation of cAMP-dependent protein kinase. The elevation of cAMP by PGE2 was still evident at 1 h and maintained through a 4-h incubation. Concentrations of PGE2 which activated the protein kinase produced a dose-dependent inhibition of surface expression of I-A and transcription of class II MHC genes. Inhibition of IFN gamma-induced class II MHC gene product expression was also observed in macrophages treated with agents which activated cAMP-dependent protein kinase by postreceptor mechanisms. Dibutyryl-cAMP (0.01-1 mM), 25 microM forskolin, 0.1 micrograms/ml cholera toxin, and 3-isobutyl-1-methylxanthine (0.1-1 mM) each suppressed IFN gamma-induced cell surface I-A expression, class II MHC gene transcription, and 22Na+ influx. The results are consistent with the suggestion that activation of cAMP-dependent protein kinase regulates an early transductional event initiated by IFN gamma, perhaps Na+/H+ exchange, which is involved in regulating transcription of class II MHC genes and their subsequent expression.
Keywords: Ciências da saúde
Medicina
Patologia clínica
Citation: FIGUEIREDO, Florêncio. et al. Activation of the CAMP Cascade Inhibits an Early Event Involved in Murine Macrophage Ia Expression. The Journal of Biological Chemistry, v. 165, n. 21, p. 12317-12323, 1990.
metadata.dc.rights: Acesso Aberto
URI: http://hdl.handle.net/123456789/202
https://repositorio.ucb.br:9443/jspui/handle/123456789/7425
Issue Date: 1990
Appears in Collections:PPG - Revistas e Artigos Científicos



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