Nitric Oxide Resistance in () Involves Regulation of Glucose Consumption, Glutathione Metabolism and Abundance of Pentose Phosphate Pathway Enzymes.

In American Tegumentary Leishmaniasis production of cytokines, reactive oxygen species and nitric oxide (NO) by host macrophages normally lead to parasite death. However, some strains exhibit natural NO resistance. NO-resistant strains cause more lesions and are frequently more resistant to antimonial treatment than NO-susceptible ones, suggesting that NO-resistant parasites are endowed with specific mechanisms of survival and persistence.

Quantitative analysis of proteins secreted by Leishmania (Viannia) braziliensis strains associated to distinct clinical manifestations of American Tegumentary Leishmaniasis.

The role of Leishmania braziliensis in the development of different clinical forms of American Tegumentary Leishmaniasis (ATL) is unclear, but it has been suggested that molecules secreted/released by parasites could modulate the clinical outcome. Here, we analyzed the infection rate and cytokine profile of macrophages pretreated with the secretome of two L. braziliensis strains associated with polar clinical forms of ATL: one associated with localized self-healing cutaneous leishmaniasis (LCL) and other associated with the disseminated form (DL).

In-depth quantitative proteomics uncovers specie-specific metabolic programs in Leishmania (Viannia) species.

Leishmania species are responsible for a broad spectrum of diseases, denominated Leishmaniasis, affecting over 12 million people worldwide. During the last decade, there have been impressive efforts for sequencing the genome of most of the pathogenic Leishmania spp. as well as hundreds of strains, but large-scale proteomics analyses did not follow these achievements and the Leishmania proteome remained mostly uncharacterized.

In-Depth Quantitative Proteomic Analysis of Trophozoites and Pseudocysts of Trichomonas vaginalis.

Trichomonas vaginalis is a sexually transmitted anaerobic parasite that infects humans causing trichomoniasis, a common and ubiquitous sexually transmitted disease. The life cycle of this parasite possesses a trophozoite form without a cystic stage. However, the presence of nonproliferative and nonmotile, yet viable and reversible spherical forms with internalized flagella, denominated pseudocysts, has been commonly observed for this parasite.

Morphologic study of the effect of iron on pseudocyst formation in Trichomonas vaginalis and its interaction with human epithelial cells.

Background: Trichomonas vaginalis is the aetiological agent of human trichomoniasis, which is one of the most prevalent sexually transmitted diseases in humans. Iron is an important element for the survival of this parasite and the colonisation of the host urogenital tract.

Objectives: In this study, we investigated the effects of iron on parasite proliferation in the dynamics of pseudocyst formation and morphologically characterised iron depletion-induced pseudocysts.

Iron-modulated pseudocyst formation in Tritrichomonas foetus.

Iron is an essential element for the survival of trichomonads during host-parasite interaction. The availability of this metal modulates several metabolic pathways of the parasites and regulates the expression of virulence factors such as adhesins and proteolytic enzymes. In this study, we investigated the effect of iron depletion on the morphology and life cycle of Tritrichomonas foetus.

Proteomics reveals major components of oogenesis in the reproductive tract of sugar-fed Anopheles aquasalis.

Anopheles (Nyssorhynchus) aquasalis is a malaria vector mainly distributed along the coastal regions of South and Central America. In the absence of an effective vaccine against malaria, strategies for controlling the vector are the main tool for interrupting parasite transmission. Mechanisms of oogenesis and embryogenesis in anautogenous mosquitoes are mainly modulated by blood feeding.

Expression of active trypsin-like serine peptidases in the midgut of sugar-feeding female Anopheles aquasalis.

Background: Anopheles aquasalis is a dipteran of the family Culicidae that is widely distributed in the coastal regions of South and Central America. This species acts as a vector of Plasmodium vivax, an important etiological agent of malaria, which represents a serious public health problem. In mosquitoes, trypsin-like serine proteases are important in blood meal digestion, immune responses and reproductive functions.

The midgut of Aedes albopictus females expresses active trypsin-like serine peptidases.

Background: Aedes albopictus is widely distributed across tropical and sub-tropical regions and is associated with the transmission of several arboviruses. Although this species is increasingly relevant to public health due its ability to successfully colonize both urban and rural habitats, favoring the dispersion of viral infections, little is known about its biochemical traits, with all assumptions made based on studies of A. aegypti.

Proteomics advances in the study of Leishmania parasites and leishmaniasis.

Leishmania spp. are digenetic parasites which cause a broad spectrum of fatal diseases in humans. These parasites, as well as the other trypanosomatid, regulate gene expression at the post-transcriptional and post-translational levels, so that a poor correlation is observed between mRNA content and translated proteins.

Protein expression in the midgut of sugar-fed Aedes albopictus females.

Background: Aedes albopictus is a vector for several fatal arboviruses in tropical and sub-tropical regions of the world. The midgut of the mosquito is the first barrier that pathogens must overcome to establish infection and represents one of the main immunologically active sites of the insect. Nevertheless, little is known about the proteins involved in the defense against pathogens, and even in the processing of food, and the detoxification of metabolites.

A proteomics view of programmed cell death mechanisms during host-parasite interactions.

Protozoan parasites are responsible for an impressive disease burden in developing and less-developed countries. The development of vaccines and effective new therapies for dealing with these organisms are among the main gaps to be filled in the control of protozoan parasite diseases. Programmed cell death (PCD) pathways have gained attention in recent years because they comprise complex signalling pathways that can be explored for therapeutic developments.

Characterization of an ecto-5'-nucleotidase activity present on the cell surface of Tritrichomonas foetus.

Tritrichomonas foetus is the causative agent of sexually transmitted trichomoniasis in cattle. In females, the infection can be associated with infertility, vaginitis, endometritis, abortion or pyometra, leading to significant economic losses in cattle raising. T.

Expression of trypsin-like serine peptidases in pre-imaginal stages of Aedes aegypti (Diptera: Culicidae).

This study reports the biochemical characterization and comparative analyses of highly active serine proteases in the larval and pupal developmental stages of Aedes aegypti (Linnaeus) using substrate-SDS-PAGE. Zymographic analysis of larval stadia detected proteolytic activity in 6-8 bands with apparent molecular masses ranging from 20 to 250 kDa, with activity observed from pH 5.5 to 10.

Cysteine peptidase expression in Trichomonas vaginalis isolates displaying high- and low-virulence phenotypes.

In the present study, we identified and characterized the cysteine peptidase (CP) profiles of Trichomonas vaginalis isolates exhibiting high- and low-virulence phenotypes using a combination of two-dimensional SDS-PAGE (2DE), tandem mass spectrometry (MS/MS), and data mining. Seven of the eight CPs identified belong to Clan CA, family C1, cathepsin L-like CP, and one belongs to Clan CD, family C13, asparaginyl endopeptidase-like CP. Quantitative and qualitative differences in CP expression were detected between the isolates.

Serine protease activities in Oxysarcodexia thornax (Walker) (Diptera: Sarcophagidae) first instar larva.

We report for the first time the expression of multiple protease activities in the first instar larva (L1) of the flesh fly Oxysarcodexia thornax (Walker). Zymographic analysis of homogenates from freshly obtained L1 revealed a complex proteolytic profile ranging from 21.5 to 136 kDa.

Differential soluble protein expression between Trichomonas vaginalis isolates exhibiting low and high virulence phenotypes.

A comparative analysis of proteomic maps of long-term grown and fresh clinical Trichomonas vaginalis isolates exhibiting low and high virulence phenotypes, respectively, was performed using two-dimensional gel electrophoresis and mass spectrometry. Of 29 protein spots differentially expressed between the isolates, 19 were over-expressed in the isolate exhibiting high virulence phenotype: proteins associated with cytoskeletal dynamics, such as coronin and several isoforms of actin, as well as proteins involved in signal transduction, protein turnover, proteolysis, and energetic and polyamine metabolisms were identified. Some malate dehydrogenase, fructose-1,6-bisphosphate aldolase and ornithine cyclodeamidase isoforms were exclusively expressed by the highly virulent isolate.

Cellular localization and expression of gp63 homologous metalloproteases in Leishmania (Viannia) braziliensis strains.

Leishmania (Viannia) braziliensis is the major causative agent of American tegumentary leishmaniasis, a disease that encompasses a broad spectrum of clinical manifestations. In a previous study, we showed that Brazilian and Colombian L. braziliensis strains, isolated from patients with distinct clinical manifestations, display different pattern of metalloprotease activities.

Application of two-dimensional electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for proteomic analysis of the sexually transmitted parasite Trichomonas vaginalis.

Trichomonas vaginalis is a sexually transmitted protozoan parasite that infects the human urogenital tract causing trichomoniasis, a worldwide disease. In this work, a fresh clinical isolate of T. vaginalis was used for study of the protein expression in this species.

A further proteomic study on the effect of iron in the human pathogen Trichomonas vaginalis.

Iron is an essential element to support the growth and survival of Trichomonas vaginalis. It plays a critical role in the host-parasite interaction, and modulates the expression of virulence factors in this protozoan. In this work, parasites grown in iron-rich and iron-depleted media were analyzed by (i) light and scanning electron microscopy and (ii) 2-DE and MS.

Proteome analysis of Leishmania (Viannia) braziliensis by two-dimensional gel electrophoresis and mass spectrometry.

Leishmania (Viannia) braziliensis, a protozoan parasite widespread in the New World, is responsible for the infection of different mammal orders, including humans. This species is considered to be a major etiological agent of American cutaneous leishmaniasis. A proteomic study was carried out to identify proteins expressed by L.

Iron modulates ecto-phosphohydrolase activities in pathogenic trichomonads.

The presence of iron in the extracellular medium is essential for both in vivo and in vitro survival of pathogenic microorganisms, including Trichomonas vaginalis and Tritrichomonas foetus. In these parasites, iron is directly involved in the proliferation, protein expression and activation of critical enzymes. The purpose of this study was to investigate the role of iron in ecto-ATPase, ecto-phophatase and secreted phosphatase activities of these trichomonads.

An ectonucleotide ATP-diphosphohydrolase activity in Trichomonas vaginalis stimulated by galactose and its possible role in virulence.

This work describes the ability of living Trichomonas vaginalis to hydrolyze extracellular ATP (164.0 +/- 13.9 nmol Pi/h x 10(7) cells).