Publications by authors named "Claudio Vieira da Silva"

Galectin-3 (Gal-3) is a β-galactoside-binding lectin expressed in cells of the placental microenvironment. This lectin is involved in various biological processes, such as modulation of the immune system and control of parasitic illness. infection can lead to congenital transmission and cause miscarriages, prematurity and fetal anomalies.

View Article and Find Full Text PDF

The protozoan parasite Trypanosoma cruzi, the etiological agent of Chagas disease, affects millions of people worldwide. Current treatments rely on drugs effective only in the acute phase, making the search for new therapeutic targets a priority. While a recombinant protein based on T.

View Article and Find Full Text PDF

Congenital Chagas disease (CCD) is a worldwide neglected problem with significant treatment limitations. This study aimed to evaluate the potential of Copaifera spp. oleoresins (ORs) against Trypanosoma cruzi infection in trophoblast cells (BeWo lineage) and human chorionic villous explants (HCVE).

View Article and Find Full Text PDF

P21 is a protein secreted by all forms of () with recognized biological activities determined in studies using the recombinant form of the protein. In our recent study, we found that the ablation of P21 gene decreased Y strain axenic epimastigotes multiplication and increased intracellular replication of amastigotes in HeLa cells infected with metacyclic trypomastigotes. In the present study, we investigated the effect of P21 using C2C12 cell lines infected with tissue culture-derived trypomastigotes (TCT) of wild-type and P21 knockout (TcP21) Y strain, and using an experimental model of infection in BALB/c mice.

View Article and Find Full Text PDF

Background: Leishmaniasis, a neglected disease caused by the parasite Leishmania, is treated with drugs associated with high toxicity and limited efficacy, in addition to constant reports of the emergence of resistant parasites. In this context, snake serums emerge as good candidates since they are natural sources with the potential to yield novel drugs.

Objectives: We aimed to show the antileishmanial effects of γCdcPLI, a phospholipase A2 inhibitor from Crotalus durissus collilineatus snake serum, against Leishmania (Leishmania) amazonensis.

View Article and Find Full Text PDF

Introduction: is the etiologic agent of toxoplasmosis, a disease that affects about one-third of the human population. Most infected individuals are asymptomatic, but severe cases can occur such as in congenital transmission, which can be aggravated in individuals infected with other pathogens, such as HIV-positive pregnant women. However, it is unknown whether infection by other pathogens, such as , the etiologic agent of Chagas disease, as well as one of its proteins, P21, could aggravate infection.

View Article and Find Full Text PDF

Many pathogenic organisms need to reach either an intracellular compartment or the cytoplasm of a target cell for their survival, replication or immune system evasion. Intracellular pathogens frequently penetrate into the cell through the endocytic and phagocytic pathways (clathrin-mediated endocytosis, phagocytosis and macropinocytosis) that culminates in fusion with lysosomes. However, several mechanisms are triggered by pathogenic microorganisms - protozoan, bacteria, virus and fungus - to avoid destruction by lysosome fusion, such as rupture of the phagosome and thereby release into the cytoplasm, avoidance of autophagy, delaying in both phagolysosome biogenesis and phagosomal maturation and survival/replication inside the phagolysosome.

View Article and Find Full Text PDF

Breast cancer is considered the type of cancer that most affects women in the world. The triple negative breast cancer is considered aggressive with poor prognosis. In the 1930s Russian researchers observed that T.

View Article and Find Full Text PDF

Pentachloropseudilin (PClP) is a reversible and allosteric inhibitor of type 1 myosin. Here, we addressed the impact of PClP treatment of Trypanosoma cruzi and mammalian host cell on the parasite migration, cell adhesion and invasion. We observed that PClP was not toxic to either T.

View Article and Find Full Text PDF

P21 is an immunomodulatory protein expressed throughout the life cycle of , the etiologic agent of Chagas disease. and studies have shown that P21 plays an important role in the invasion of mammalian host cells and establishment of infection in a murine model. P21 functions as a signal transducer, triggering intracellular cascades in host cells and resulting in the remodeling of the actin cytoskeleton and parasite internalization.

View Article and Find Full Text PDF

Congenital toxoplasmosis is represented by the transplacental passage of Toxoplasma gondii from the mother to the fetus. Our studies demonstrated that T. gondii developed mechanisms to evade of the host immune response, such as cyclooxygenase (COX)-2 and prostaglandin E (PGE) induction, and these mediators can be produced/stored in lipid droplets (LDs).

View Article and Find Full Text PDF

P21 is a protein secreted by the parasite that plays biological roles directly involved in the progression of Chagas disease. The recombinant protein (rP21) demonstrates biological properties, such as binding to CXCR4 receptors in macrophages, chemotactic activity of immune cells, and inhibiting angiogenesis. This study aimed to verify the effects of rP21 interaction with CXCR4 from non-tumoral cells (MCF-10A) and triple-negative breast cancer cells (MDA-MB-231).

View Article and Find Full Text PDF

Background: Eugenia calycina is an endemic species in the Brazilian savannah (the Cerrado) and it is threatened with extinction. Several species of Eugenia are used as insecticides or insect repellents. No data are available on the larvicidal activity of E.

View Article and Find Full Text PDF

P21 protein (P21) is a putative secreted and immunomodulatory molecule with potent bioactive properties such as induction of phagocytosis and actin cytoskeleton polymerization. Despite the bioactive properties described so far, the action of P21 on parasite replication in muscle cell lineage or parasitism during acute experimental infection is unclear. We observed that recombinant P21 (rP21) decreased the multiplication of in C2C12 myoblasts, phenomenon associated with greater actin polymerization and IFN-γ and IL-4 higher expression.

View Article and Find Full Text PDF

B cells contribute to the immune system in many ways such as antigen presentation to CD4 T cells, secretion of cytokines and lymphoid tissue organogenesis. Furthermore, they are the only cell type capable of producing immunoglobulins. B cells also account for critical aspects of the resistance against intracellular pathogens.

View Article and Find Full Text PDF

Background: TcP21 is a ubiquitous secreted protein of Trypanosoma cruzi and its recombinant form (rP21) promotes parasite cell invasion and acts as a phagocytosis inducer by activating actin polymerisation in the host cell.

Objective: Our goal was to evaluate if the additional supplementation of rP21 during a prime/boost/challenge scheme with T. cruzi TCC attenuated parasites could modify the well-known protective behavior conferred by these parasites.

View Article and Find Full Text PDF

Class 1 myosins (Myo1s) were the first unconventional myosins identified and humans have eight known Myo1 isoforms. The Myo1 family is involved in the regulation of gene expression, cytoskeletal rearrangements, delivery of proteins to the cell surface, cell migration and spreading. Thus, the important role of Myo1s in different biological processes is evident.

View Article and Find Full Text PDF

IL-9 is a pleiotropic cytokine, recently recognized as belonging to Th9 cells that are involved in various pathologies. We aimed to evaluate the role of IL-9 in the course of hepatic and renal fibrosis. Female C57BL/6 mice were treated subcutaneously with IL-9 10 ng/mouse and 20 ng/mouse for 40 days, alternating every 5 days each application, the negative control of which was treated with PBS and positive control with CCL.

View Article and Find Full Text PDF

Some metallodrugs that exhibit interesting biological activity contain transition metals such as ruthenium, and have been extensively exploited because of their antiparasitic potential. In previous study, we reported the remarkable anti-Leishmania activity of precursor cis-[RuCl(dppm)], where dppm = bis(diphenylphosphino)methane, and new ruthenium(II) complexes, cis-[Ru(η-OCCH)(dppm)]PF (bbato), cis-[Ru(η-OCCHS)(dppm)]PF (mtbato) and cis-[Ru(η-OCCHO)(dppm)]PF (hmxbato) against some Leishmania species. In view of the promising activity of the hmxbato complex against Leishmania (Leishmania) amazonensis promastigotes, the present work investigated the possible parasite death mechanism involved in the action of this hmxbato and its precursor.

View Article and Find Full Text PDF

This work reports the biological evaluation of a copper complex of the type [Cu(O-O)(N-N)ClO], in which O-O = 4,4,4-trifluoro-1-phenyl-1,3-butanedione (Hbta) and N-N = 1,10-phenanthroline (phen), whose generic name is CBP-01. The cytotoxic effect of CBP-01 was evaluated by resazurin assay and cell proliferation was determined by MTT assay. DNA fragmentation was analyzed by gel electrophoresis.

View Article and Find Full Text PDF

Leishmaniasis is one of the most important neglected tropical diseases (NTDs) that are especially common among low-income populations in developing regions of Africa, Asia, and the Americas. Many natural products, particularly alkaloids, have been reported to have inhibitory activity against arginase, the key enzyme in the pathology caused by Leishmania sp. In this way, piperidine alkaloids (-)-cassine (1), (-)-spectaline (2), (-)-3-O-acetylcassine (3), and (-)-3-O-acetylspectaline (4) were isolated from Senna spectabilis flowers.

View Article and Find Full Text PDF

Herein we evaluated the genotoxic effects of BnSP-6, a Lys-49 phospholipase A (PLA) from Bothrops pauloensis, on breast cancer cells. BnSP-6 was able to induce a higher cytotoxic and genotoxic activity in MDA-MB-231 cells, when compared to MCF10A (a non-tumorigenic breast cell line), suggesting that this protein presented a possible preference for cancer cells. BnSP-6 inhibited MDA-MB-231 proliferation at 24, 48 and 72 h.

View Article and Find Full Text PDF

Natural products represent a source of biologically active molecules that have an important role in drug discovery. The aromatic plant has a diverse chemical constitution but the biological activities of its essential oils have not been thoroughly investigated. The aims of this paper were to evaluate in vitro cytotoxic, antifungal and antibacterial activities of an essential oil from leaves of and to identify its main chemical constituents.

View Article and Find Full Text PDF

Chronic chagasic cardiomyopathy (CCC) is arguably the most important form of the Chagas Disease, caused by the intracellular protozoan Trypanosoma cruzi; it is estimated that 10-30% of chronic patients develop this clinical manifestation. The most common and severe form of CCC can be related to ventricular abnormalities, such as heart failure, arrhythmias, heart blocks, thromboembolic events and sudden death. Therefore, in this study, we proposed to evaluate the anti-angiogenic activity of a recombinant protein from T.

View Article and Find Full Text PDF

Host actin cytoskeleton polymerization has been shown to play an important role during Trypanosoma cruzi internalization into mammalian cell. The structure and dynamics of the actin cytoskeleton in cells are regulated by a vast number of actin-binding proteins. Here we aimed to verify the impact of AFAP-1L1, during invasion and multiplication of T.

View Article and Find Full Text PDF