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Jan Votýpka - One of the best experts on this subject based on the ideXlab platform.

  • Trypanosomatid parasites in Austrian mosquitoes.
    PloS one, 2018
    Co-Authors: Ellen Schoener, Sarah Susanne Uebleis, Claudia Cuk, Michaela Nawratil, Adelheid G. Obwaller, Thomas Zechmeister, Karin Lebl, Jana Rádrová, Carina Zittra, Jan Votýpka
    Abstract:

    Trypanosomatid flagellates have not been studied in Austria in any detail. In this study, specific nested PCR, targeted on the ribosomal small subunit, was used to determine the occurrence and diversity of trypanosomatids in wild-caught mosquitoes sampled across Eastern Austria in the years 2014−2015. We collected a total of 29,975 mosquitoes of 19 species divided in 1680 pools. Of these, 298 (17.7%), representing 12 different mosquito species, were positive for trypanosomatid DNA. In total, seven trypanosomatid spp. were identified (three Trypanosoma, three Crithidia and one Herpetomonas species), with the highest parasite species diversity found in the mosquito host Coquillettidia richiardii. The most frequent parasite species belonged to the mammalian Trypanosoma theileri/cervi species complex (found in 105 pools; 6.3%). The avian species T. culicavium (found in 69 pools; 4.1%) was only detected in mosquitoes of the genus Culex, which corresponds to their preference for avian hosts. Monoxenous trypanosomatids of the genus Crithidia and Herpetomonas were found in 20 (1.3%) mosquito pools. One third (n = 98) of the trypanosomatid positive mosquito pools carried more than one parasite species. This is the first large scale study of trypanosomatid parasites in Austrian mosquitoes and our results are valuable in providing an overview of the diversity of these parasites in Austria.

  • An unexpected diversity of trypanosomatids in fecal samples of great apes
    Elsevier, 2018
    Co-Authors: Jan Votýpka, Barbora Pafčo, David Modrý, Donald Mbohli, Nikki Tagg, Klára J. Petrželková
    Abstract:

    Charismatic great apes have been used widely and effectively as flagship species in conservation campaigns for decades. These iconic representatives of their ecosystems could also play a role as reservoirs of several zoonotic diseases. Recently it was demonstrated that African great apes can host Leishmania parasites (Kinetoplastea: Trypanosomatidae). Given that this finding raised a strong negative reaction from leishmania experts and the subsequent discussion did not lead to a clear resolution, we decided to analyze wild gorilla (Gorilla gorilla gorilla) and chimpanzee (Pan troglodytes troglodytes) fecal samples collected from the same area in Cameroon as in the original study. Fecal samples, used to circumvent the difficulties and ethics involved in obtaining blood samples from endangered wild apes, were screened by three different PCR assays for detection of Leishmania DNA. We did not detect any leishmania parasites in analyzed feces; however, sequencing of SSU rRNA revealed an unexpected diversity of free-living bodonids (Kinetoplastea: Bodonidae) and parasitic trypanosomatids (Kinetoplastea: Trypanosomatidae) other than Leishmania. A single detected Phytomonas species, found in chimpanzee feces, most likely originated from animal plant food. On the other hand, the presence of four free-living bodonid species and four parasitic insect monoxenous trypanosomatid, including two possible new species of the genus Herpetomonas, could be explained as ex post contamination of feces either from the environment or from flies (Diptera: Brachycera). Keywords: Leishmania, Herpetomonas, Trypanosomatids, Detection, Gorilla, Chimpanzee, Feces, PC

  • Diversity of Trypanosomatids in Cockroaches and the Description of Herpetomonas tarakana sp. n.
    The Journal of eukaryotic microbiology, 2015
    Co-Authors: Vyacheslav Yurchenko, Alexei Y. Kostygov, Jolana Havlová, Anastasiia Grybchuk-ieremenko, Tereza Ševčíková, Julius Lukeš, Jan Ševčík, Jan Votýpka
    Abstract:

    In this study, we surveyed six species of cockroaches, two synanthropic (i.e. ecologically associated with humans) and four wild, for intestinal trypanosomatid infections. Only the wild cockroach species were found to be infected, with flagellates of the genus Herpetomonas. Two distinct genotypes were documented, one of which was described as a new species, Herpetomonas tarakana sp. n. We also propose a revision of the genus Herpetomonas and creation of a new subfamily, Phytomonadinae, to include Herpetomonas, Phytomonas, and a newly described genus Lafontella n. gen. (type species Lafontella mariadeanei comb. n.), which can be distinguished from others by morphological and molecular traits.

  • Herpetomonas trimorpha sp nov trypanosomatidae kinetoplastida a parasite of the biting midge culicoides truncorum ceratopogonidae diptera
    International Journal of Systematic and Evolutionary Microbiology, 2010
    Co-Authors: Lenka Zidkova, Jan Votýpka, Ivan Cepicka, Milena Svobodova
    Abstract:

    Monoxenous trypanosomatid Herpetomonas trimorpha sp. nov. was isolated from the digestive tract of the biting midge Culicoides truncorum (Ceratopogonidae, Diptera). This species forms three distinct morphotypes in culture: the microflagellate promastigote, the small promastigote and the long promastigote. The last form is unique for the newly described species. Phylogenetic analyses of SSU rRNA and glycosomal glyceraldehyde phosphate dehydrogenase genes showed that H. trimorpha sp. nov. is the closest relative of Herpetomonas ztiplika, another monoxenous trypanosomatid isolated from biting midges. However, morphological and randomly amplified polymorphic DNA analyses confirmed that H. trimorpha sp. nov. is distinct from H. ztiplika.

  • Herpetomonas ztiplika n sp kinetoplastida trypanosomatidae a parasite of the blood sucking biting midge culicoides kibunensis tokunaga 1937 diptera ceratopogonidae
    Journal of Parasitology, 2004
    Co-Authors: Sergei A Podlipaev, Jan Votýpka, Milena Svobodova, Milan Jirků, Julius Lukeš
    Abstract:

    Herein, we describe the first case of a natural infection of biting midges by a kinetoplastid protozoan. Flagellates from a female Culicoides kibunensis captured in a bird's nest were introduced into culture and characterized by light and electron microscopy. However, because the morphological data were inconclusive, the novel endosymbiont-free trypanosomatid was assigned into Herpetomonas primarily on the basis of the 18S and 5S ribosomal RNA (rRNA) gene sequences.

Maurilio J. Soares - One of the best experts on this subject based on the ideXlab platform.

  • Infection of Mouse Dermal Fibroblasts by the Monoxenous Trypanosomatid Protozoa Crithidia deanei and Herpetomonas roitmani
    The Journal of eukaryotic microbiology, 2004
    Co-Authors: Dilvani Oliveira Santos, Maurilio J. Soares, Saulo C. Bourguignon, Helena Carla Castro, Jonatan S. Silva, Leonardo S. Franco, Renata C. Hespanhol, Suzana Corte-real
    Abstract:

    Traditionally, monoxenous trypanosomatid protozoa are not believed to infect vertebrate cells. Using light and electron microscopy, we show that the monoxenous trypanosomatids Crithidia deanei and Herpetomonas roitmani are able to infect dermal mouse fibroblasts in vitro. We present experimental evidence of phagocytosis of these trypanosomatids, and demonstrate their survival in vertebrate cells. This paper raises the question about the role of C. deanei and H. roitmani, and perhaps other monoxenous trypanosomatid species, in opportunistic infections of immunocompromised individuals and cutaneos lesions in vertebrate hosts.

  • Morphological, Biochemical and Molecular Characterization of Herpetomonas samuelpessoai camargoi n. subsp., a Trypanosomatid Isolated from the Flower of the Squash Cucurbita moschata
    The Journal of eukaryotic microbiology, 2001
    Co-Authors: João Evangelista Fiorini, Maurilio J. Soares, Marta Maria Geraldes Teixeira, Carmen S. A. Takata, Virginia M. Teofilo, Luiz Carlos Do Nascimento, Paulo M. Faria-e-silva, Wanderley De Souza
    Abstract:

    We report the morphological, biochemical and molecular characteristics of a trypanosomatid isolated from the flower of Cucurbita moschata. Although the trypanosomatid was isolated from a plant, the lack of recognition of Phytomonas-specific molecular markers based on spliced-leader and ribosomal genes as well as by monoclonal antibodies specific for Phytomonas argues against assigning it to this genus. Because the isolate displayed typical opisthomastigote forms in culture, it is assigned to the genus Herpetomonas. Analysis of randomly amplified polymorphic DNA (RAPD) patterns and characterization of ribosomal SSU and ITS markers suggest that it is more closely related to H. samuelpessoai than to any other species. However, the presence of spined flagellates in culture (displaying lateral expansions of the plasma membrane originating near the flagellar pocket) and isolate-specific RAPD fingerprints argue strongly that the trypanosomatid belongs to a new subspecies, for which the name Herpetomonas samuelpessoai camargoi n. subsp. is proposed.

  • Effect of Platelet-Activating Factor on the Process of Cellular Differentiation of Herpetomonas muscarum muscarum
    The Journal of eukaryotic microbiology, 1997
    Co-Authors: Angela H. Lopes, Maurilio J. Soares, Jayme Angluster, Patrı́cia M.l. Dutra, Claudia O. Rodrigues, Renato S. B. Cordeiro
    Abstract:

    The effects of platelet-activating factor (PAF), at doses ranging from 10(-6) M to 10(-10) M, on cell growth and on cell differentiation of Herpetomonas muscarum muscarum were investigated. Cell differentiation was evaluated by both light and electron microscopy. At the concentrations used, PAF did not interfere with the protozoan growth. However, parasites grown in the presence of PAF (10(-6) M) were significantly more differentiated than those grown in the absence of PAF, since the first day of culture. On the first two days of culture, PAF doses ranging from 10(-10) M to 10(-7) M, did not significantly interfere with the differentiation of these parasites, although after the third day of culture, all PAF doses used significantly increased the protozoan differentiation. Specific PAF receptor antagonists totally abrogated (WEB 2086 and WEB 2170) or significantly decreased (BN 52021) PAF effect on cell differentiation. These findings indicate PAF triggers the process of cell differentiation in Herpetomonas muscarum muscarum and suggest these parasites have receptors for PAF.

  • Proliferative opisthomastigote forms in Herpetomonas roitmani (Kinetoplastida: Trypanosomatidae)
    Parasitology research, 1996
    Co-Authors: Paulo M. Faria-e-silva, Maurilio J. Soares, W. De Souza
    Abstract:

    The flagellate Herpetomonas roitmani is a symbiont-bearing trypanosomatid that spontaneously differentiates from promastigote to para- and opisthomastigote forms when maintained in axenic culture medium. Thus, after cultivation for 72 h at 28°C, 37% of the total number of cells are in the opisthomastigote form. In the present study, light microscopy observations of Giemsa-stained H. roitmani cells demonstrated that in early cultures (12 h at 28°C) the percentage of opisthomastigotes was markedly high (about 98%). Furthermore, proliferative opisthomastigote forms (dividing cells with the kinetoplast posteriorly located relative to the nucleus) were frequently seen in these cultures. The latter observation was confirmed by analysis of routinely fixed parasites by transmission electron microscopy.

  • Herpetomonas roitmani (Fiorini et al., 1989) n. comb.: a trypanosomatid with a bacterium-like endosymbiont in the cytoplasm.
    The Journal of protozoology, 1991
    Co-Authors: P. M. Faria E Silva, Maurilio J. Soares, Antonio M. Solé-cava, Maria Cristina M. Motta, João Evangelista Fiorini, W. De Souza
    Abstract:

    The trypanosomatid previously described as Crithidia roitmani is characterized here at the ultrastructural and biochemical levels. The data indicates that the parasite belongs to the Herpetomonas genus, and we therefore suggest the flagellate to be denominated as Herpetomonas roitmani n. comb. Cladistic analysis of isoenzyme data generated by eight different enzymes showed that the parasite presented a distinct banding pattern and could be grouped with some Herpetomonas spp., but not with Crithidia spp., used as reference strains. Accordingly, when the parasites were grown for longer periods in Roitman's defined medium, expontaneous differentiation from promastigotes to opisthomastigotes (typical of the Herpetomonas genus) occurred. Transmission electron microscopy revealed the presence of bacterium-like endosymbionts in the cytoplasm of all evolutive forms of the parasite. All morphological alterations characteristic of endosymbiont-bearing trypanosomatids could be observed.

Michel Dollet - One of the best experts on this subject based on the ideXlab platform.

  • Isolation of a Protozoan Parasite Genetically Related to the Insect Trypanosomatid Herpetomonas samuelpessoai from a Human Immunodeficiency Virus-Positive Patient
    Journal of clinical microbiology, 2008
    Co-Authors: Florent Morio, Michel Dollet, Jean-pierre Dedet, Jacques Reynes, Francine Pratlong, Christophe Ravel
    Abstract:

    Severely immunocompromised human immunodeficiency virus (HIV) patients can develop various opportunistic infections due to bacteria, viruses, fungi, or protozoa. Here we report the first isolation of a flagellated protozoan genetically closely related to Herpetomonas samuelpessoai, which is usually a parasite of insects, from the blood of an HIV-infected patient.

  • Herpetomonas spp. isolated from tomato fruits (Lycopersicon esculentum) in southern Spain
    Experimental parasitology, 2007
    Co-Authors: Clotilde Marín, Sandrine Fabre, Manuel Sánchez-moreno, Michel Dollet
    Abstract:

    A flagellate of the family Trypanosomatidae was isolated from fruits of Lycopersicon esculentum (tomato) in southeastern Spain. The isolate was successfully adapted to in vitro culture in monophasic media. The morphology showed the kinetoplast to be positioned towards the middle of the body, and the typical opistomastigote form characteristic of members of the genus Herpetomonas. Amplification of the mini-exon gene was negative, whilst for the 5S ribosomal rRNA gene the result was positive. The DNA sequence was obtained and its alignment with other trypasomatids, obtained using the BLAST algorithm, suggested it was closely related to Herpetomonas samuelpessoai.

  • Research brief Herpetomonas spp. isolated from tomato fruits (Lycopersicon esculentum) in southern Spain
    2007
    Co-Authors: Clotilde Marín, Sandrine Fabre, Manuel Sánchez-moreno, Michel Dollet
    Abstract:

    A Xagellate of the family Trypanosomatidae was isolated from fruits of Lycopersicon esculentum (tomato) in southeastern Spain. The isolate was successfully adapted to in vitro culture in monophasic media. The morphology showed the kinetoplast to be positioned towards the middle of the body, and the typical opistomastigote form characteristic of members of the genus Herpetomonas. AmpliWcation of the mini-exon gene was negative, whilst for the 5S ribosomal rRNA gene the result was positive. The DNA sequence was obtained and its alignment with other trypasomatids, obtained using the BLAST algorithm, suggested it was closely related to Herpetomonas samuelpessoai.

  • Phytomonas iron superoxide dismutase: a possible molecular marker
    FEMS microbiology letters, 2004
    Co-Authors: Clotilde Marín, Michel Dollet, Ana B. Hitos, Isabel Rodríguez-gonzález, Manuel Sánchez-moreno
    Abstract:

    We have isolated and biochemically characterized two iron superoxide dismutases activities (SODI and SODII) from a plant trypanosomatid isolated from Euphorbia characias. The isoenzyme FeSODII has immunogenic capacity, and the positivity of the anti-SODII serum persists to a dilution of 1/40,000, by Western blot. In addition, Western blot has been used to test the positivity of the anti-SODII serum against antigen fractions (SOD) from 17 isolates belonging to the family Trypanosomatidae and for which we had previously determined the isoenzymatic profile. The reaction proved positive only with those plant isolates considered to belong to the genus Phytomonas, whereas there was no reaction of the anti-SODII serum, against the antigen fractions from the species Trypanosoma cruzi, Leishmania donovani, Herpetomonas samuelpessoai, Herpetomonas davidi, Crithidia luciliae and Leptomonas collosoma. FeSODII is located mainly over the entire surface of the parasite, as well as in the nucleus, glycosomes and membranes. The above makes FeSODII promising as a molecular tool for diagnosis and identification, and as a potential chemotherapeutic target for designing drugs aimed at controlling not only of the diseases caused by Phytomonas species, but also for the great metabolic similarity to other trypanosomatids of animals and humans, it may be possible for these results to be extrapolated. Moreover, the sequencing of the amino-terminal end of the FeSODII enables the design of primers that in the near future will make it possible to sequence the gene of this isoenzyme.

  • Infection of plants by flagellate protozoa (Phytomonas spp., Trypanosomatidae)
    Electron Microscopy of Plant Pathogens, 1991
    Co-Authors: Michel Dollet
    Abstract:

    The existence of trypanosomes in latex plants has been known since 1909 [12]. Immediately after their discovery, Donovan proposed the generic name Phytomonas [9], although these organisms had not been characterized in any way. The classification of trypanosomes is currently as follows: Order Kinetoplastida, Suborder Trypanosomatina, Family Trypanosomatidae [15]. Beside this arbitrarily created genus Phytomonas, the following genera exist: Leptomonas, Herpetomonas, Crithidia, Blastocrithidia, and Rhynchoidomonas, which are insect trypanosomatids. Endotrypanum and Trypanosoma are animal and human trypanosomatids transmitted by insects.

Erney P Camargo - One of the best experts on this subject based on the ideXlab platform.

  • Kinetoplastid genealogies of ACD protein families.
    2018
    Co-Authors: André G. Costa-martins, Erney P Camargo, Luciana Lima, João Marcelo P. Alves, Myrna G. Serrano, Gregory A. Buck, Marta M. G. Teixeira
    Abstract:

    Maximum likelihood genealogies of TrySGT1 (A); TryDYX1C1 (B); ATOM69 (C) and HSP20 (D). ML trees inferred using whole predicted amino acid sequences and models were automatic selected by AIC criteria using PROTGAMMAAUTO option. Branch are colored according to clades and lineages as fallowed: gray, free-living bodonids; skyblue, trypanosome Aquatic clade; purple, T. brucei clade; forest-green, crocodilian clade; magenta, T. theileri/T. cyclops clade; red, T. lewisi/T. cruzi clade; green, Phytomonas; blue, Herpetomonas; yellow, Angomonas; orange, Strigomonas; olive-green, Crithidia/Leptomonas; Cyan, Leishmaniinae. Numbers on branches represent bootstrap support estimated with 500 pseudoreplicates.

  • Molecular phylogenetic redefinition of Herpetomonas (Kinetoplastea, Trypanosomatidae), a genus of insect parasites associated with flies.
    Protist, 2012
    Co-Authors: Tarcilla Corrente Borghesan, Marta Maria Geraldes Teixeira, Carmen S. A. Takata, Robson C. Ferreira, Marta Campaner, Charlotte C. Borda, Fernando Paiva, Regina Vugman Milder, Erney P Camargo
    Abstract:

    In order to review the taxonomy of the genus Herpetomonas through phylogenetic and morphological analyses we barcoded 527 insect trypanosomatids by sequencing the V7V8 region of the small subunit ribosomal RNA (SSU rRNA) gene. Fifty two flagellates, 90% of them from Diptera, revealed to be related to known species of Herpetomonas. Sequences of entire glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) and SSU rRNA genes were employed for phylogenetic inferences including representatives of all genera of Trypanosomatidae. In the resulting phylogenetic trees, the selected flagellates clustered into a monophyletic assemblage that we are considering as the redefined genus Herpetomonas. Internal transcribed spacer 1 (ITS1) rDNA sequences and putative secondary structures of this region were compared for evaluation of inter- and intraspecific variability. The flagellates were classified in six already known species and five new species. In addition, two Leptomonas spp. were moved to Herpetomonas, now comprising 13 valid species, while four species were excluded from the genus. Light and electron microscopy revealed the extreme polymorphism of Herpetomonas, hindering genus and species identification by morphological characteristics. Our findings also showed that some species of Herpetomonas are generalist parasites of flies and appear to be as cosmopolitan as their hosts.

  • Phytomonas and other trypanosomatid parasites of plants and fruit.
    Advances in parasitology, 1999
    Co-Authors: Erney P Camargo
    Abstract:

    Abstract Trypanosomatid parasites are fairly common in the latex, phloem, fruit sap, seed albumen, and even in the nectar, of many plant families. They are transmitted to the plants in the saliva of phytophagous hemipterous bugs (Insecta). Morphologically, plant trypanosomatids have no special characteristic, except perhaps a very twisted cell body. Most occur in plants as promastigotes and a few as choanomastigotes. It is still controversial whether or not they are pathogenic in lactiferous plants or fruit, but it is certain that the phloem parasites are pathogenic in coconut palms and coffee bushes. In these plants, they cause lethal diseases responsible for the destruction of many plantations in Central and South America, but fortunately nowhere else in the world. Probably more than one genus of Trypanosomatidae is represented among the plant parasites. The most important is certainly Phytomonas, but Leptomonas, Crithidia and Herpetomonas may also be present. The distinction between them is difficult and only recently have molecular markers become available to help in their identification. At present, Phytomonas can be identified by DNA hybridization with a specific probe (SL3') complementary to a sequence of the mini-exam or spliced leader gene. The development of a polymerase chain reaction coupled to SL3' hybridization has facilitated the detection of Phytomonas in plants. The phylogeny of Phytomonas is still being worked out. For the moment it can only be said that the genus is very close to Herpetomonas.

  • RIBOSOMAL AND kDNA MARKERS DISTINGUISH TWO SUBGROUPS OF Herpetomonas AMONG OLD SPECIES AND NEW TRYPANOSOMATIDS ISOLATED FROM FLIES
    The Journal of parasitology, 1997
    Co-Authors: Marta Maria Geraldes Teixeira, Mahta Campaner, Ivete Conchon, Carmen S. A. Takata, Erney P Camargo
    Abstract:

    We examined flies of various families for the presence of trypanosomatids. Of 592 insects, 113 (19%) were positive. From these insects, we obtained 42 cultures and selected 14 for further analysis. Seven of the cultures had the characteristics of Herpetomonas species, they displayed typical opisthomastigotes, lacked arginase, possessed a Pvu H restriction site at 360 bp from the 5' end of the small subunit ribosomal gene, and did not possess a Hin dIII site at 1,500 bp from the ribosomal ao-large subunit 5' end. Hybridization with synthetic oligonucleotides complementary to the sequences flanking the Pvu II site in Her- petomonas samuelpessoai and Herpetomonas muscarum, permitted the distribution of the old species and the 7 isolates into 2 subgroups of Herpetomonas spp. Of the remaining 7 cultures, 4 were probably Leptomonas spp., whereas the other 3, together with Herpetomonas roitmani, seem to constitute a novel group with morphological and molecular characteristics quite distinct from those of Herpetomonas spp. or any other genera of Trypanosomatidae. We also studied some trypanosomatid species of questionable taxonomic status, Leptomonas samueli and Phytomonas davidi yielded results identical to those of Herpetomonas spp., thus confirming their already suspected affiliation to this genus. On the other hand, Herpetomonas anglusteri, Herpetomonas dedonderi, and Herpetomonas mcgheei displayed morphological and molecular characteristics incompatible with their placement in the genus Herpetomonas. As redefined by Hoare and Wallace (1966), the trypanoso- matid genus Herpetomonas comprises monoxenic parasites of insects that present pro- and opisthomastigotes in their life cy- cles. Despite this clear-cut definition, many trypanosomatids have been erroneously placed in the genus Herpetomonas or, conversely, many Herpetomonas spp. may remain hidden in other genera. This was due either by the nonadherence of au- thors to the above generic definition or to the inherent difficul- ties in detecting opisthomastigotes in cultures, whose occur- rence may be erratic or difficult to notice among the predomi- nant promastigotes (Wallace, 1966, 1979; Camargo et al., molecular markers in this genus should be preceded by obtain- ing a larger number of Herpetomonas isolates. In this paper, we initially isolated 42 cultures of trypanosomatids recovered from flies, the putative preferential host of Herpetomonas, and then proceeded to examine specific kDNA and genomic DNA mark- ers in 14 of them. Results were compared with those of the available species of Herpetomonas and of other genera of the Trypanosomatidae.

Angela H. Lopes - One of the best experts on this subject based on the ideXlab platform.

  • Lysophosphatidylcholine triggers cell differentiation in the protozoan parasite Herpetomonas samuelpessoai through the CK2 pathway
    Acta Parasitologica, 2020
    Co-Authors: Fernando L. Dutra, Danielle P. Vieira, Felipe S. Coelho, Camila M. Adade, Geórgia C. Atella, Mário A. C. Silva Neto, Angela H. Lopes
    Abstract:

    Background Protozoa are distantly related to vertebrates but present some features of higher eukaryotes, making them good model systems for studying the evolution of basic processes such as the cell cycle. Herpetomonas samuelpessoai is a trypanosomatid parasite isolated from the hemipteran insect Zelus leucogrammus. Lysophosphatidylcholine (LPC) is implicated in the transmission and establishment of Chagas disease, whose etiological agent is Trypanosoma cruzi . LPC is synthesized by T. cruzi and its vectors, the hemipteran Rhodnius prolixus and Triatoma infestans. Platelet-activating factor (PAF), a phospholipid with potent and diverse physiological and pathophysiological actions, is a powerful inducer of cell differentiation in Herpetomonas muscarum muscarum and T. cruzi . The enzyme phospholipase A_2 (PLA_2) catalyzes the hydrolysis of the 2-ester bond of 3-sn-phosphoglyceride, transforming phosphatidylcholine (PC) into LPC. Methods In this study, we evaluated cellular differentiation, PLA_2 activity and protein kinase CK2 activity of H. samuelpessoai in the absence and in the presence of LPC and PAF. Results: We demonstrate that both PC and LPC promoted a twofold increase in the cellular differentiation of H. samuelpessoai , through CK2, with a concomitant inhibition of its cell growth. Intrinsic PLA_2 most likely directs this process by converting PC into LPC. Conclusions Our results suggest that the actions of LPC on H. samuelpessoai occur upon binding to a putative PAF receptor and that the protein kinase CK2 plays a major role in this process. Graphic abstract Cartoon depicting a model for the synthesis and functions of LPC in Herpetomonas samuelpessoai , based upon our results regarding the role of LPC on the cell biology of Trypanosoma cruzi [ 28 – 32 ]. N nucleus, k kinetoplast, PC phosphatidylcholine, LPC lysophosphatidylcholine, PLA _ 2 phospholipase A_2, PAFR putative PAF receptor in trypanosomatids [ 65 ], CK2 protein kinase CK2 [ 16 ].

  • Characterization of Ca2+ uptake in a subcellular membrane fraction of Herpetomonas sp. promastigotes.
    Parasitology, 2009
    Co-Authors: Cl Sodre, Hm Scofano, B. L. M. Moreira, J.r. Meyer-fernandes, Patrícia Maria Lourenço Dutra, Angela H. Lopes, Hector Barrabin
    Abstract:

    ATP-dependent Ca 2+ uptake was studied in a subcellular fraction from Herpetomonas sp. prepared by mechanical disruption and using 45 Ca 2+ as a tracer. The uptake was stimulated by Ca 2+ with a K 0.5 of 0·1 μM and a Hill number (n H )=2·8±0·4. The Ca 2+ -dependent ATP hydrolysis was optimal at pH 7·0 and had a Ca 2+ dependence identical to uptake. The uptake was highly stimulated by oxalate whereas calmodulin had no activating effect. ATP stimulated Ca 2+ uptake with a biphasic pattern that resembled the curves described for the purified preparations of rabbit sarcoplasmic reticulum. The ATP stimulation is described as the sum of two Michaelis-Menten curves with Kml = 0·25±0·19 μM and Km2 = 29·6±6·8 μM. GTP or UTP could also promote Ca 2+ uptake, but with less efficiency than ATP. Vanadate inhibited the uptake with low apparent affinity. Thapsigargin and cyclopiazonic acid were almost ineffective. The Ca 2+ uptake was insensitive to H + ionophores and to bafilomycin suggesting no participation of acidocalcisomes. The results are comparable to those obtained using cells permeabilized with digitonin and using arsenaze III as Ca 2+ indicator. The Ca 2+ uptake activity described here seems to belong to the endoplasmic reticulum of Herpetomonas sp. and is suitable for further studies on the mechanisms of calcium homeostasis in parasites.

  • Platelet-activating factor (PAF) activates casein kinase 2 in the protozoan parasite Herpetomonas muscarum muscarum.
    Biochemical and biophysical research communications, 2002
    Co-Authors: Mário A. C. Silva Neto, Danielle P. Vieira, Alan B. Carneiro, Rafael D. Mesquita, Angela H. Lopes
    Abstract:

    Herpetomonas muscarum muscarum is a flagellate parasite of the family Trypanosomatidae, whose cell differentiation can be triggered by the lipid mediator, PAF. In this study we demonstrate for the first time that PAF effect relies on the activation of casein kinase 2 (CK2). The classical antagonist of PAF receptor, WEB 2086, abrogated PAF-enhanced CK2 activity. CK2 activation by PAF was also inhibited when parasite extracts were assayed in the presence of modulators of PKC, MAPK, and both Ser/Thr and Tyr phosphatases. Finally, a cell permeable inhibitor of CK2 (DRB) suppressed PAF-induced cell differentiation in a dose-dependent manner.

  • Characterization of the Intracellular Ca2+ Pools Involved in the Calcium Homeostasis in Herpetomonas sp. Promastigotes
    Archives of biochemistry and biophysics, 2000
    Co-Authors: Cl Sodre, Fb Nobrega, Ae Vercesi, Hm Scofano, B. L. M. Moreira, Fernanda R. Gadelha, J.r. Meyer-fernandes, Patrícia Maria Lourenço Dutra, Angela H. Lopes, Hector Barrabin
    Abstract:

    Trypanosomatids of the genus Herpetomonas comprises monoxenic parasites of insects that present pro- and opisthomastigotes forms in their life cycles. In this study, we investigated the Ca(2+) transport and the mitochondrial bioenergetic of digitonin-permeabilized Herpetomonas sp. promastigotes. The response of promastigotes mitochondrial membrane potential to ADP, oligomycin, Ca(2+), and antimycin A indicates that these mitochondria behave similarly to vertebrate and Trypanosoma cruzi mitochondria regarding the properties of their electrochemical proton gradient. Ca(2+) transport by permeabilized cells appears to be performed mainly by the mitochondria. Unlike T. cruzi, it was not possible to observe Ca(2+) release from Herpetomonas sp. mitochondria, probably due to the simultaneous Ca(2+) uptake by the endoplasmic reticulum. In addition, a vanadate-sensitive Ca(2+) transport system, attributed to the endoplasmic reticulum, was also detected. Nigericin (1 microM), FCCP (1 microM), or bafilomycin A(1) (5 microM) had no effect on the vanadate-sensitive Ca(2+) transport. These data suggest the absence of a Ca(2+) transport mediated by a Ca(2+)/H(+) antiport. No evidence of a third Ca(2+) compartment with the characteristics of the acidocalcisomes described by A. E. Vercesi et al. (1994, Biochem. J. 304, 227-233) was observed. Thapsigargin and IP(3) were not able to affect the vanadate-sensitive Ca(2+) transport. Ruthenium red was able to inhibit the Ca(2+) uniport of mitochondria, inducing a slow mitochondrial Ca(2+) efflux, compatible with the presence of a Ca(2+)/H(+) antiport. Moreover, this efflux was not stimulated by the addition of NaCl, which suggests the absence of a Ca(2+)/Na(+) antiport in mitochondria.

  • Effect of Platelet-Activating Factor on the Process of Cellular Differentiation of Herpetomonas muscarum muscarum
    The Journal of eukaryotic microbiology, 1997
    Co-Authors: Angela H. Lopes, Maurilio J. Soares, Jayme Angluster, Patrı́cia M.l. Dutra, Claudia O. Rodrigues, Renato S. B. Cordeiro
    Abstract:

    The effects of platelet-activating factor (PAF), at doses ranging from 10(-6) M to 10(-10) M, on cell growth and on cell differentiation of Herpetomonas muscarum muscarum were investigated. Cell differentiation was evaluated by both light and electron microscopy. At the concentrations used, PAF did not interfere with the protozoan growth. However, parasites grown in the presence of PAF (10(-6) M) were significantly more differentiated than those grown in the absence of PAF, since the first day of culture. On the first two days of culture, PAF doses ranging from 10(-10) M to 10(-7) M, did not significantly interfere with the differentiation of these parasites, although after the third day of culture, all PAF doses used significantly increased the protozoan differentiation. Specific PAF receptor antagonists totally abrogated (WEB 2086 and WEB 2170) or significantly decreased (BN 52021) PAF effect on cell differentiation. These findings indicate PAF triggers the process of cell differentiation in Herpetomonas muscarum muscarum and suggest these parasites have receptors for PAF.