Effects of 4,4′-diisothyocyanatostilbene-2,2′-disulfonic acid on Trypanosoma cruzi proliferation and Ca2+ homeostasis

Bernardes, Celene Fernandes; Meyer‐Fernandes, José Roberto; Saad-Nehme, Jorge; Vannier-Santos, Marcos A.; Peres-Sampaio, Carlos E.; Vercesi, Anı́bal E.

doi:10.1016/s1357-2725(00)00002-9

Cited by 36 publications

(27 citation statements)

References 42 publications

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“…3A and B, open circles). We have previously shown that DIDS inhibits T. cruzi epimastigote cell growth (Bernardes et al 2000), and that this inhibition is supposed to be related to ectoenzymes involved in cell proliferation (Berreˆdo-Pinho et al 2001). ATP and other nucleotides stimulate the proliferation of different cell types, while the inhibition of the ecto-ATPase, 5¢ nucleotidase and alkaline phosphatase moderate the stimulatory effect of ATP (Lemmens et al 1996).…”

Section: Resultsmentioning

confidence: 99%

A Mg-dependent ecto-ATPase is increased in the infective stages of Trypanosoma cruzi

et al. 2004

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In this work, we describe the ability of living epimastigotes of Trypanosoma cruzi to hydrolyze extracellular ATP. In these intact parasites, there was a low level of ATP hydrolysis in the absence of any divalent metal (2.42 +/- 0.31 nmol Pi/h x 10(8) cells). ATP hydrolysis was stimulated by MgCl2, and the Mg-dependent ecto-ATPase activity was 27.15 +/- 2.91 nmol Pi/h x 10(8) cells. The addition of MgCl2 to the extracellular medium increased the ecto-ATPase activity in a dose-dependent manner. This stimulatory activity was also observed when MgCl2 was replaced by MnCl2, but not by CaCl2 or SrCl2. The apparent Km for Mg-ATP2- was 0.61 mM, and free Mg2+ did not increase the ecto-ATPase activity. This ecto-ATPase activity was insensitive to the inhibitors of other ATPase and phosphatase activities. To confirm that this Mg-dependent ATPase was an ecto-ATPase, we used an impermeant inhibitor, DIDS (4, 4'.diisothiocyanostylbene 2'-2'-disulfonic acid) as well as suramin, an antagonist of P2 purinoreceptors and inhibitor of some ecto-ATPases. These two reagents inhibited the Mg2+-dependent ATPase activity in a dose-dependent manner. A comparison among the Mg2+-ecto-ATPase activities of the three forms of T. cruzi showed that the noninfective epimastigotes were less efficient at hydrolyzing ATP than the infective trypomastigote and amastigote stages.

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Section: Resultsmentioning

confidence: 99%

A Mg-dependent ecto-ATPase is increased in the infective stages of Trypanosoma cruzi

et al. 2004

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“…Several hypotheses have been proposed for the function of ecto-ATPases in trypanosomatids, which include acquisition of Ado from the media, necessary for normal growth, modulation of parasite infection and virulence, and involvement in cellular adhesion [17], [27], [34]–[43].…”

Section: Resultsmentioning

confidence: 99%

Ecto-Nucleotidase Activities of Promastigotes from Leishmania (Viannia) braziliensis Relates to Parasite Infectivity and Disease Clinical Outcome

et al. 2012

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Background Leishmania (Viannia) braziliensis has been associated with a broad range of clinical manifestations ranging from a simple cutaneous ulcer to destructive mucosal lesions. Factors leading to this diversity of clinical presentations are not clear, but parasite factors have lately been recognized as important in determining disease progression. Given the fact that the activity of ecto-nucleotidases correlates with parasitism and the development of infection, we evaluated the activity of these enzymes in promastigotes from 23 L. braziliensis isolates as a possible parasite-related factor that could influence the clinical outcome of the disease.Methodology/Principal FindingsOur results show that the isolates differ in their ability to hydrolyze adenine nucleotides. Furthermore, we observed a positive correlation between the time for peak of lesion development in C57BL/6J mice and enzymatic activity and clinical manifestation of the isolate. In addition, we found that L. (V.) braziliensis isolates obtained from mucosal lesions hydrolyze higher amounts of adenine nucleotides than isolates obtained from skin lesions. One isolate with high (PPS6m) and another with low (SSF) ecto-nucleotidase activity were chosen for further studies. Mice inoculated with PPS6m show delayed lesion development and present larger parasite loads than animals inoculated with the SSF isolate. In addition, PPS6m modulates the host immune response by inhibiting dendritic cell activation and NO production by activated J774 macrophages. Finally, we observed that the amastigote forms from PPS6m and SSF isolates present low enzymatic activity that does not interfere with NO production and parasite survival in macrophages.Conclusions/SignificanceOur data suggest that ecto-nucleotidases present on the promastigote forms of the parasite may interfere with the establishment of the immune response with consequent impaired ability to control parasite dissemination and this may be an important factor in determining the clinical outcome of leishmaniasis.

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“…The physiological role of the ecto-ATPases is still unknown, but a possible involvement in cell proliferation has been proposed (Lemmens et al 1996;Bernardes et al 2000;Berreˆdo-Pinho et al 2001). The trypanosomatidae family includes species that cannot synthesize purines de novo and thus are dependent on exogenous sources of these essential nutrients (Cohn and Gottlieb 1997;Gero 1998).…”

Section: Resultsmentioning

confidence: 99%

“…Ecto-ATPases have been described in some protozoa such as Toxoplasma gondii (Asai and Suzuki 1990;Bermudes et al 1994;Asai et al 1995;Nakaar et al 1998), Entamoeba histolytica (Barkker-Grunwald and Parduhn 1993; Barros et al 2000), Tetrahymena thermophila (Smith et al 1997), Leishmania tropica , Leishmania amazonensis (Berreˆdo-Pinho et al 2001) and Trypanosoma cruzi (Bernardes et al 2000). In this study we show for the first time the presence of Mg 2+ -dependent ecto-ATP diphosphohydrase activity on the surface of living cells of the monoxenic trypanosomatid protozoan C. deanei and characterize the properties of this enzyme.…”

Section: Introductionmentioning

confidence: 99%

Ectonucleotide diphosphohydrolase activity in Crithidia deanei

Lemos

Pinheiro

Berrêdo-Pinho

et al. 2002

Parasitology Research

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In this work we describe the ability of living Crithidia deanei to hydrolyze extracellular ATP. In intact cells at pH 7.2, a low level of ATP hydrolysis was observed in the absence of any divalent metal (0.41+/-0.13 nmol P(i) h(-1) 10(7) cells(-1)). The ATP hydrolysis was stimulated by MgCl(2) and the Mg(2+)-dependent ecto-ATPase activity was 4.05+/-0.17 nmol P(i) h(-1) 10(7) cells(-1). Mg(2+)-dependent ecto-ATPase activity increased linearly with cell density and with time for at least 60 min. The addition of MgCl(2) to extracellular medium increased the ecto-ATPase activity in a dose-dependent manner. At 5 mM ATP, half-maximal stimulation of ATP hydrolysis was obtained with 0.93+/-0.26 mM MgCl(2). This stimulatory activity was also observed when MgCl(2) was replaced by MnCl(2), but not CaCl(2) or SrCl(2). The apparent K(m) for Mg-ATP(2-) was 0.26+/-0.03 mM. ATP was the best substrate for this enzyme; other nucleotides, such as ITP, GTP, UTP and CTP, produced lower reaction rates. In the pH range from 6.6 to 8.4, in which the cells were viable, the acid phosphatase activity also present in this cell decreased, while the Mg(2+)-dependent ATPase activity did not change. This ecto-ATPase activity was insensitive to inhibitors of other ATPase and phosphatase activities, such as oligomycin, sodium azide, bafilomycin A(1), ouabain, vanadate, molybdate, sodium fluoride and tartrate. To confirm that this Mg(2+)-dependent ATPase was an ecto-ATPase, we used the impermeant inhibitor 4, 4'-diisothiocyanostylbene 2'-2'-disulfonic acid as well as suramin, an antagonist of P(2) purinoreceptors and inhibitor of some ecto-ATPases. These two reagents inhibited the Mg(2+)-dependent ATPase activity in a dose-dependent manner. The cell surface location of the ATP-hydrolyzing site was also confirmed by cytochemical analysis.

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Effects of 4,4′-diisothyocyanatostilbene-2,2′-disulfonic acid on Trypanosoma cruzi proliferation and Ca2+ homeostasis

Cited by 36 publications

References 42 publications

A Mg-dependent ecto-ATPase is increased in the infective stages of Trypanosoma cruzi

A Mg-dependent ecto-ATPase is increased in the infective stages of Trypanosoma cruzi

Ecto-Nucleotidase Activities of Promastigotes from Leishmania (Viannia) braziliensis Relates to Parasite Infectivity and Disease Clinical Outcome

Ectonucleotide diphosphohydrolase activity in Crithidia deanei

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