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Title

1,25-dihydroxyvitamin D3 induces responsiveness to the chemotactic peptide f-Met-Leu-Phe in the human monocytic line U937: dissociation between calcium and oxidative metabolic responses

Authors
Polla, B. S.
Werlen, G.
Rossier, M. F.
Published in Journal of Leukocyte Biology. 1989, vol. 45, no. 5, p. 381-388
Abstract In the human premonocytic line U937, 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) induces a functional NADPH oxidase, that is responsive to both phorbol esters and opsonized zymosan. The chemotactic peptide f-Met-Leu-Phe (fMLP) did not, however, induce superoxide generation by these cells. This was not due to the absence of receptors for fMLP. Although there was no significant binding of [3H]-fMLP to undifferentiated U937 cells, preincubation with 1,25-(OH)2D3 induced expression of specific and saturable binding sites. Moreover, fMLP induced a rapid and reversible rise in cytosolic free Ca2+ concentration ([Ca2+]i) in 1,25-(OH)2D3-treated U937 cells, but not in control or 24,25-dihydroxyvitamin D3 (24,25-(OH)2D3)-treated cells. This [Ca2+]i response was dependent on concentrations of both fMLP and 1,25-(OH)2D3 and was observed at physiologic concentrations of the hormone (approximately 25 pM). The rise in [Ca2+]i induced by fMLP in 1,25-(OH)2D3-treated U937 cells was blocked by pertussis toxin and presumably mediated by inositol (1,4,5)-trisphosphate generation. These results indicate that in U937 cells differentiated with 1,25-(OH)2D3, inositol phosphate-mediated [Ca2+]i responses to fMLP are uncoupled from NADPH oxidase activation.
Keywords Calcitriol/ pharmacologyCalcium/metabolismCell Differentiation/drug effectsCell LineHumansInositol 1,4,5-TrisphosphateInositol Phosphates/biosynthesisMonocytes/ drug effects/metabolismN-Formylmethionine Leucyl-Phenylalanine/metabolism/ pharmacologySuperoxides/biosynthesis
Identifiers
PMID: 2540255
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Other version: http://www.jleukbio.org/cgi/reprint/45/5/381.pdf
Structures
Research group Staphylocoques dorés résistants à la méthicilline et hygiène hospitalière (330)
Citation
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POLLA, B. S. et al. 1,25-dihydroxyvitamin D3 induces responsiveness to the chemotactic peptide f-Met-Leu-Phe in the human monocytic line U937: dissociation between calcium and oxidative metabolic responses. In: Journal of Leukocyte Biology, 1989, vol. 45, n° 5, p. 381-388. https://archive-ouverte.unige.ch/unige:7523

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Deposited on : 2010-06-21

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