RESUMO
Schistosomiasis is a major neglected disease that imposes a substantial worldwide health burden, affecting approximately 250â million people globally. As praziquantel is the only available drug to treat schistosomiasis, there is a critical need to identify new anthelmintic compounds, particularly from natural sources. To enhance the activity of different natural products, one potential avenue involves its combination with silver nanoparticles (AgNP). Based on this approach, a one-step green method for the inâ situ preparation of dehydrodieugenol (DHDG) by oxidation coupling reaction using silver and natural eugenol is presented. AgNP formation was confirmed by UV-Vis spectroscopy due to the appearance of the surface plasmon resonance (SPR) band at 430â nm which is characteristic of silver nanoparticles. The nanoparticles were spherical with sizes in the range of 40 to 50â nm. Bioassays demonstrated that the silver nanoparticles loaded with DHDG exhibited significant anthelmintic activity against Schistosoma mansoni adult worms without toxicity to mammalian cells and an inâ vivo animal model (Caenorhabditis elegans), contributing to the development of new prototypes based on natural products for the treatment of schistosomiasis.
Assuntos
Anti-Helmínticos , Anti-Infecciosos , Produtos Biológicos , Eugenol/análogos & derivados , Lignanas , Nanopartículas Metálicas , Esquistossomose , Animais , Humanos , Prata/farmacologia , Prata/química , Nanopartículas Metálicas/química , Anti-Helmínticos/farmacologia , Anti-Helmínticos/uso terapêutico , Esquistossomose/tratamento farmacológico , Anti-Infecciosos/uso terapêutico , Schistosoma mansoni , Produtos Biológicos/uso terapêutico , MamíferosRESUMO
Schistosomiasis is a widely distributed parasitic disease and one of the most important neglected tropical diseases globally, for which Praziquantel® (PZQ) is the only available treatment. In this context, tests with new PZQ formulations become relevant for disease control. This study evaluated the effects of PZQ treatment in the prepatent phase of schistosomiasis using two formulations: nanoencapsulated (PZQ-NANO) and active pharmaceutical ingredient (PZQ-API). Five experimental groups were established, for which the following serological parameters were evaluated: ALT, AST, ALP, and TP. Animals treated with PZQ-API at 15 and 30 days post-infection showed decreased eggs per gram of feces (EPG) compared to untreated infected animals. The same animals showed reductions of 63.6 and 65.1%, respectively, at 60 days post-infection. Animals treated with PZQ-NANO experienced no significant changes in EPG at any time of observation. Animals treated with either PZQ-API or PZQ-NANO had higher ALT and AST levels in the patent period (60 and 90 days post-infection). Treatment with PZQ, either API or NANO, at 15 days post-infection reduced AST, ALT, and TP levels. It is concluded that prepatent treatment with PZQ-API can reduce the parasite load of infected animals and that treatment at 15 days post-infection can prevent increased serum levels of ALT, AST, and TP.
Assuntos
Esquistossomose mansoni , Esquistossomose , Animais , Modelos Animais de Doenças , Camundongos , Praziquantel/farmacologia , Praziquantel/uso terapêutico , Schistosoma mansoni , Esquistossomose/tratamento farmacológico , Esquistossomose/prevenção & controle , Esquistossomose mansoni/parasitologiaRESUMO
Schistosoma mansoni is the main causative agent of intestinal schistosomiasis which affects millions of people worldwide. At the larval stage, miracidia are released into bodies of water where they utilize their motility to successfully infect their intermediate host, snails. Here, we revisit the motility and survival of S. mansoni miracidia throughout its life span. Briefly, miracidia motility was monitored at 30-min and 60-min intervals under the presence/absence of natural/artificial light. Based on a subjective evaluation of activity, body shape and transparency, 6 categories of miracidia activity were established from its fully active stage to its immobile larva stage. The estimated life span of miracidia was 5.8 and 3.5 h in the experiments with 60-min and 30-min observation intervals, respectively. Death was defined by an absence of cilia and body movement. When mobility was used as a proxy for infectivity, infective miracidia were detected at 2.5 and 4.5 h, respectively. The present miracidia motility and survival re-evaluation supports parameters optimization for computational modelling of schistosomiasis transmission dynamics. Target control interventions, especially at late stages next to transmission interruption, may greatly benefit from improved modelling studies.
Assuntos
Biomphalaria , Esquistossomose mansoni , Animais , Simulação por Computador , Humanos , Larva , Schistosoma mansoni , CaramujosRESUMO
Transposable elements (TEs) are DNA sequences able to transpose within the host genome and, consequently, influence the dynamics of evolution in the species. Among the possible effects, TEs insertions may alter the expression and coding patterns of genes, leading to genomic innovations. Gene-duplication events, resulting from DNA segmental duplication induced by TEs transposition, constitute another important mechanism that contributes to the plasticity of genomes. This review aims to cover the current knowledge regarding TEs in the genome of the parasite Schistosoma mansoni, an agent of schistosomiasis-a neglected tropical disease affecting at least 250 million people worldwide. In this context, the literature concerning TEs description and TEs impact on the genomic architecture for S. mansoni was revisited, displaying evidence of TEs influence on schistosome speciation-mediated by bursts of transposition-and in gene-duplication events related to schistosome-host coevolution processes, as well several instances of TEs contribution into the coding sequences of genes. These findings indicate the relevant role of TEs in the evolution of the S. mansoni genome.
RESUMO
Schistosomiasis remains one of the most important neglected tropical diseases in the world. It mainly affects developing countries, where it often coexists with malnutrition. Despite this, few studies have investigated the relationship between schistosomiasis and malnutrition. Herein, we evaluate the impact of malnutrition on experimental S. mansoni infection. Mice were divided into 5 groups: Control (Ctrl) diet (14% protein and 10% lipids), low-protein 3% (LP 3%), low-protein 8% (LP 8%), low-fat 2.5% (LF 2.5%), and low-fat 5% (LF 5%). Mice were fed with their respective diets and were infected when a difference of approximately 20% in the body weight between mice from any experimental group and mice from the control group was achieved. Nutritional, parasitological, and immunological parameters were assessed either just before infection and/or approximately 50 days later before mice were perfused. Our results showed that the 3% low-protein diet was the only one capable of establishing malnutrition in mice. Mice fed with this diet showed: (i) significant reduction in body weight and serum albumin levels before infection, (ii) decreased levels of all biochemical parameters evaluated before perfusion, (iii) decreased numbers of schistosome eggs trapped in intestines and impaired parasite fecundity, (iv) a delay in the granuloma development with a smaller granuloma area, and (v) reduced levels of IL-4 and IFN-γ in the liver. Our findings demonstrate that low protein supply leads to malnutrition in mice and impacts the cytokine milieu in the liver and granuloma formation. Additionally, the establishment of our murine malnutrition model will enable future studies aiming to better understand the complex relationships between nutrition, immune responses, and infection outcome.
RESUMO
An important aspect of host-pathogen interactions is the interference of secreted proteins with the fibrinolytic system. Herein, we describe a modified ELISA method used to evaluate the interaction of a recombinant Schistosoma mansoni protein with plasminogen (PLG). Using this protocol, we demonstrated that a secreted protein, recombinant venom allergen-like protein 18 (rSmVAL18) acts as a plasminogen receptor increasing its activation into plasmin in the presence of the urokinase-type plasminogen activator (uPA). PLG binding was determined by immobilizing human PLG in the plate and incubating with the recombinant protein; competitive binding with a lysine analog demonstrated the interaction of the protein lysine residues with PLG Kringle domains. To assess the activation of S. mansoni recombinant protein-bound PLG, the amidolytic activity of generated plasmin was measured using the D-Val-Leu-Lys 4-nitroanilide dihydrochloride substrate.
Assuntos
Ensaio de Imunoadsorção Enzimática/métodos , Proteínas de Helminto/metabolismo , Plasminogênio/metabolismo , Schistosoma mansoni/metabolismo , Ácido Aminocaproico/metabolismo , Animais , Ligação Competitiva , Fibrinolisina/metabolismo , Humanos , Ligação ProteicaRESUMO
The present work aimed to carry out in vitro biological assays of indol-3-yl derivatives thiosemicarbazones (2a-e) and 4-thiazolidinones (3a-d) against juvenile and adult worms of S. mansoni, as well as the in silico determination of pharmacokinetic parameters for the prediction of the oral bioavailability of these derivatives. All compounds were initially screened at a concentration of 200⯵M against S. mansoni adult worms and the results evidenced the good activity of compounds 2b, 2d and 3b, which caused 100% mortality after 24, 48 and 72â¯h, respectively. Subsequent studies with these same compounds revealed that compound 2b was able to reduce the viability of the parasites by 85% and 83% at concentrations of 200 and 100⯵M, respectively. In relation to the juvenile worms, all compounds (2b, 2d and 3b) were able to cause mortality, but compound 2b demonstrated better activity causing 100% mortality in 48â¯h. Additionally, it was possible to observe reduction in the viability of juvenile worms of 85%, 81% and 64% at concentrations of 200, 100 and 50⯵M, respectively. Several ultrastructural damages were observed when adult and juvenile S. mansoni worms were exposed to compound 2b (200⯵M) that was characterized by extensive destruction by the integument, which may justify the mortality rate of cultured parasites. In the DNA interaction assay, fragmentation of the genetic material of adult worms when treated with compound 2b (200⯵M) was evidenced, indicating the apoptosis process as mechanism of parasite death. Regarding pharmacokinetic properties, all derivatives are according to the required parameters, predicting good oral bioavailability for the studied compounds. The results presented in this study reveal the good activity of compound 2b in both adult and juvenile worms of S. mansoni, pointing this compound as promising in the development of further studies on schistosomicidal activity.
Assuntos
Schistosoma mansoni/efeitos dos fármacos , Tiossemicarbazonas/farmacologia , Tiossemicarbazonas/farmacocinética , Animais , Helmintos/efeitos dos fármacos , Esquistossomicidas/farmacocinética , Esquistossomicidas/farmacologiaRESUMO
Background and aims: Mice orally infected with T. gondii develop Crohn's disease (CD)-like enteritis associated with severe mucosal damage and a systemic inflammatory response, resulting in high morbidity and mortality. Previously, helminthic infections have shown therapeutic potential in experimental colitis. However, the role of S. mansoni in T. gondii-induced CD-like enteritis has not been elucidated. Our study investigated the mechanisms underlying T. gondii-induced ileitis and the potential therapeutic effect of S. mansoni coinfection. Methods: C57BL/6 mice were infected by subcutaneous injection of cercariae of the BH strain of S. mansoni, and 7-9 weeks later, they were orally infected with cysts of the ME49 strain of T. gondii. After euthanasia, the ileum was removed for histopathological analysis; staining for goblet cells; immunohistochemistry characterizing mononuclear cells, lysozyme expression, apoptotic cells, and intracellular pathway activation; and measuring gene expression levels by real-time PCR. Cytokine concentrations were measured in the serial serum samples and culture supernatants of the ileal explants, in addition to myeloperoxidase (MPO) activity. Results:T. gondii-monoinfected mice presented dense inflammatory cell infiltrates and ulcerations in the terminal ileum, with abundant cell extrusion, apoptotic bodies, and necrosis; these effects were absent in S. mansoni-infected or coinfected animals. Coinfection preserved goblet cells and Paneth cells, remarkably depleted in T. gondii-infected mice. Densities of CD4- and CD11b-positive cells were increased in T. gondii- compared to S. mansoni-infected mice and controls. MPO was significantly increased among T. gondii-mice, while attenuated in coinfected animals. In T. gondii-infected mice, the culture supernatants of the explants showed increased concentrations of TNF-alpha, IFN-gamma, and IL-17, and the ileal tissue revealed increased expression of the mRNA transcripts for IL-1 beta, NOS2, HMOX1, MMP3, and MMP9 and activation of NF-kappa B and p38 MAPK signaling, all of which were counterregulated by S. mansoni coinfection. Conclusion:S. mansoni coinfection attenuates T. gondii-induced ileitis by preserving mucosal integrity and downregulating the local inflammatory response based on the activation of NF-kappa B and MAPK. The protective function of prior S. mansoni infection suggests the involvement of innate immune mechanisms and supports a conceptually new approach to the treatment of chronic inflammatory diseases, including CD.
Assuntos
Coinfecção/imunologia , Ileíte/prevenção & controle , Mucosa Intestinal/fisiopatologia , Esquistossomose mansoni/imunologia , Terapia com Helmintos , Toxoplasmose Animal/terapia , Animais , Apoptose , Doença de Crohn/terapia , Citocinas/sangue , Modelos Animais de Doenças , Regulação para Baixo , Epitélio/fisiologia , Perfilação da Expressão Gênica , Ileíte/etiologia , Ileíte/imunologia , Ileíte/patologia , Sistema de Sinalização das MAP Quinases/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Peroxidase/sangue , Síndrome de Resposta Inflamatória Sistêmica/etiologia , Síndrome de Resposta Inflamatória Sistêmica/imunologia , Toxoplasmose Animal/complicações , Toxoplasmose Animal/imunologiaRESUMO
VIP36 is a protein described as an L-type lectin in animals, responsible for the intracellular transport of glycoproteins within the secretory pathway, and also localized on the plasma membrane. Schistosoma mansoni has a complex system of vesicles and protein transport machinery to the cell surface. The excreted/secreted products of the larvae and eggs are known to be exposed to the host immune system. Hence, characterizing the role and action of SmVIP36 in the S. mansoni life cycle is important for a better understanding of the parasite-host relationship. To this purpose, we firstly performed in silico analysis. Analysis of SmVIP36 in silico revealed that it contains a lectin leg-like domain with a jellyroll fold as seen by its putative 3D tertiary structure. Additionally, it was also observed that its CRD contains calcium ion-binding amino acids, suggesting that the binding of SmVIP36 to glycoproteins is calcium-dependent. Finally, we observed that the SmVIP36 predicted amino acid sequence relative to its orthologs was conserved. However, phylogenetic analysis revealed that SmVIP36 follows species evolution, forming a further cluster with its definitive host Homo sapiens. Moreover, q-PCR analysis in the S. mansoni life cycle points to a significant increase in gene expression in the eggs, schistosomulae, and female adult stages. Similarly, protein expression increased in eggs, cercariae, schistosomulae, and adult worm stages. These results suggest that SmVIP36 might participate in the complex secretory activity within the egg envelope and tegument proteins, both important for the stages of the parasite that interact with the host.
Assuntos
Proteínas de Helminto/genética , Lectinas/genética , Proteínas de Membrana/genética , Schistosoma mansoni/crescimento & desenvolvimento , Schistosoma mansoni/genética , Sequência de Aminoácidos , Animais , Membrana Celular/genética , Membrana Celular/metabolismo , Feminino , Expressão Gênica , Proteínas de Helminto/metabolismo , Humanos , Lectinas/metabolismo , Estágios do Ciclo de Vida , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Filogenia , Transporte Proteico , Schistosoma mansoni/classificação , Schistosoma mansoni/isolamento & purificação , Esquistossomose mansoni/parasitologiaRESUMO
Mansonic schistosomiasis is a disease caused by the trematode Schistosoma mansoni, endemic to tropical countries. S. mansoni infection induces the formation of granulomas and potent polarization of Th2-type immune response. There is great interest in understanding the mechanisms used by this parasite that causes a modulation of the immune system. Recent studies from our group demonstrated that lipids of S. mansoni, including lysophosphatidylcholine (LPC) have immunomodulatory activity. In the present study, our aim was to investigate the role of lipids derived from S. mansoni in the activation and polarization of macrophages and to characterize the mechanisms involved in this process. Peritoneal macrophages obtained from wild type C57BL/6mice or bone marrow derived macrophages were stimulated in vitro with lipids extracted from adult worms of S. mansoni. We demonstrated that total schistosomal-derived lipids as well as purified LPC induced alternatively activated macrophages/M2 profile observed by increased expression of arginase-1, mannose receptor, Chi3l3, TGFß and production of IL-10 and PGE2 24h after stimulation. The involvement of the nuclear receptor PPARγ in macrophage response against LPC was investigated. Through Western blot and immunofluorescence confocal microscopy we demonstrated that schistosomal-derived LPC induces increased expression of PPARγ in macrophages. The LPC-induced increased expression of arginase-1 were significantly inhibited by the PPAR-γ antagonist GW9662. Together, these results demonstrate an immunomodulatory role of schistosomal-derived LPC in activating macrophages to a profile of the type M2 through PPARγ-dependent mechanisms, indicating a novel pathway for macrophage polarization triggered by parasite-derived LPC with potential implications to disease pathogenesis.