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Platelet-activating factor induction of secreted phosphatase activity in Trypanosoma cruzi.
Biochem Biophys Res Commun. 1999 Dec 09; 266(1):36-42.BB

Abstract

The effects of platelet-activating factor (PAF) on the ecto-phosphatase activity of Trypanosoma cruzi were investigated. Living parasites hydrolyzed p-nitrophenyl phosphate (p-NPP) at a rate of 5.71 +/- 0.37 nmol P(i) mg(-1) min(-1). This ecto-phosphatase activity increased to 8.70 +/- 1.12 nmol P(i) mg(-1) min(-1) when the cells were grown in the presence of 10(-9) M PAF. This effect was probably due to stimulation of the release of the ecto-phosphatase and/or the secretion of an intracellular phosphatase to the extracellular medium, as suggested by cytochemical analysis. Modulation of the ecto-phosphatase activity was also observed when PAF was added during the time course of the reaction. WEB 2086, a competitive PAF antagonist, was able to revert PAF effects when both were used at the same concentration. When PAF was added to a membrane enriched fraction preparation of T. cruzi, no alteration on the phosphatase activity was observed. This result suggests an involvement of intracellular signaling, as PAF was only effective on intact cells. Sphingosine and phorbol-12-myristate-13-acetate (PMA) were then used to investigate a possible involvement of protein kinase C (PKC) with PAF-induced phosphatase secretion. Sphingosine by itself stimulated the secretion of a phosphatase but did not significantly interfere with PAF effects on this enzyme. On the other hand, PMA was able to abrogate PAF-induced release of this phosphatase. These data are highly suggestive of a putative involvement of signal transduction mediated by a ligand of mammalian origin (PAF), through PKC and a specific receptor located on the cell surface of the human parasite Trypanosoma cruzi.

Authors+Show Affiliations

Instituto de Microbiologia Prof. Paulo de Góes, UFRJ, Rio de Janeiro, RJ, 21941-590, Brazil.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

10581161

Citation

Rodrigues, C O., et al. "Platelet-activating Factor Induction of Secreted Phosphatase Activity in Trypanosoma Cruzi." Biochemical and Biophysical Research Communications, vol. 266, no. 1, 1999, pp. 36-42.
Rodrigues CO, Dutra PM, Barros FS, et al. Platelet-activating factor induction of secreted phosphatase activity in Trypanosoma cruzi. Biochem Biophys Res Commun. 1999;266(1):36-42.
Rodrigues, C. O., Dutra, P. M., Barros, F. S., Souto-Padrón, T., Meyer-Fernandes, J. R., & Lopes, A. H. (1999). Platelet-activating factor induction of secreted phosphatase activity in Trypanosoma cruzi. Biochemical and Biophysical Research Communications, 266(1), 36-42.
Rodrigues CO, et al. Platelet-activating Factor Induction of Secreted Phosphatase Activity in Trypanosoma Cruzi. Biochem Biophys Res Commun. 1999 Dec 9;266(1):36-42. PubMed PMID: 10581161.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Platelet-activating factor induction of secreted phosphatase activity in Trypanosoma cruzi. AU - Rodrigues,C O, AU - Dutra,P M, AU - Barros,F S, AU - Souto-Padrón,T, AU - Meyer-Fernandes,J R, AU - Lopes,A H, PY - 1999/12/3/pubmed PY - 1999/12/3/medline PY - 1999/12/3/entrez SP - 36 EP - 42 JF - Biochemical and biophysical research communications JO - Biochem Biophys Res Commun VL - 266 IS - 1 N2 - The effects of platelet-activating factor (PAF) on the ecto-phosphatase activity of Trypanosoma cruzi were investigated. Living parasites hydrolyzed p-nitrophenyl phosphate (p-NPP) at a rate of 5.71 +/- 0.37 nmol P(i) mg(-1) min(-1). This ecto-phosphatase activity increased to 8.70 +/- 1.12 nmol P(i) mg(-1) min(-1) when the cells were grown in the presence of 10(-9) M PAF. This effect was probably due to stimulation of the release of the ecto-phosphatase and/or the secretion of an intracellular phosphatase to the extracellular medium, as suggested by cytochemical analysis. Modulation of the ecto-phosphatase activity was also observed when PAF was added during the time course of the reaction. WEB 2086, a competitive PAF antagonist, was able to revert PAF effects when both were used at the same concentration. When PAF was added to a membrane enriched fraction preparation of T. cruzi, no alteration on the phosphatase activity was observed. This result suggests an involvement of intracellular signaling, as PAF was only effective on intact cells. Sphingosine and phorbol-12-myristate-13-acetate (PMA) were then used to investigate a possible involvement of protein kinase C (PKC) with PAF-induced phosphatase secretion. Sphingosine by itself stimulated the secretion of a phosphatase but did not significantly interfere with PAF effects on this enzyme. On the other hand, PMA was able to abrogate PAF-induced release of this phosphatase. These data are highly suggestive of a putative involvement of signal transduction mediated by a ligand of mammalian origin (PAF), through PKC and a specific receptor located on the cell surface of the human parasite Trypanosoma cruzi. SN - 0006-291X UR - https://www.unboundmedicine.com/medline/citation/10581161/Platelet_activating_factor_induction_of_secreted_phosphatase_activity_in_Trypanosoma_cruzi_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0006-291X(99)91759-X DB - PRIME DP - Unbound Medicine ER -