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1.
J Virol ; 97(1): e0175222, 2023 01 31.
Artículo en Inglés | MEDLINE | ID: mdl-36602368

RESUMEN

Interleukin-27 (IL-27) is able to inhibit HIV-1 replication in peripheral blood mononuclear cells (PBMCs), macrophages, and dendritic cells. Here, we identify that IL-27 can produce opposing effects on HIV-1 replication in PBMCs and that the HIV-1 restriction factor BST-2/Tetherin is involved in both inhibitory and enhancing effects on HIV-1 infection induced by IL-27. IL-27 inhibited HIV-1 replication when added to cells 2 h after infection, promoting the prototypical BST-2/Tetherin-induced virion accumulation at the cell membrane of HIV-1-infected PBMCs. BST-2/Tetherin gene expression was significantly upregulated in the IL-27-treated PBMCs, with a simultaneous increase in the number of BST-2/Tetherin+ cells. The silencing of BST-2/Tetherin diminished the anti-HIV-1 effect of IL-27. In contrast, IL-27 increased HIV-1 production when added to infected cells 4 days after infection. This enhancing effect was prevented by BST-2/Tetherin gene knockdown, which also permitted IL-27 to function again as an HIV-1 inhibitory factor. These contrasting roles of IL-27 were associated with the dynamic of viral production, since the IL-27-mediated enhancement of virus replication was prevented by antiretroviral treatment of infected cells, as well as by keeping cells under agitation to avoid cell-to-cell contact. Likewise, inhibition of CD11a, an integrin associated with HIV-1 cell-to-cell transmission, abrogated the IL-27 enhancement of HIV-1 production. Our findings illustrate the complexity of the HIV-1-host interactions and may impact the potential therapeutic use of IL-27 and other soluble mediators that induce BST-2/Tetherin expression for HIV-1 infection. IMPORTANCE Here, we describe new findings related to the ability of the cytokine IL-27 to regulate the growth of HIV-1 in CD4+ T lymphocytes. IL-27 has long been considered a potent inhibitor of HIV-1 replication, a notion based on several reports showing that this cytokine controls HIV-1 infection in peripheral blood mononuclear cells (PBMCs), monocyte-derived macrophages, and dendritic cells. However, our present results are contrary to the current knowledge that IL-27 acts only as a powerful downregulator of HIV-1 replication. We observed that IL-27 can either prevent or enhance viral growth in PBMCs, an outcome dependent on when this cytokine is added to the infected cells. We detected that the increase of HIV-1 dissemination is due to enhanced cell-to-cell transmission with the involvement of the interferon-induced HIV-1 restriction factor BST-2/Tetherin and CD11a (LFA-1), an integrin that participates in formation of virological synapse.


Asunto(s)
Antígeno 2 del Estroma de la Médula Ósea , Infecciones por VIH , Interleucina-27 , Humanos , Integrinas , Leucocitos Mononucleares/metabolismo , Proteínas Reguladoras y Accesorias Virales
2.
Bioorg Med Chem ; 40: 116164, 2021 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-34020276

RESUMEN

A diversity-oriented synthesis of hydroxylated aryl-quinones via CH oxygenation reactions and their evaluation against Trypanosoma cruzi, the etiological agent of Chagas disease, was accomplished. With the use of ruthenium(II)- or palladium(II)-based catalysts, complementary regioselectivities were observed in the hydroxylation reactions and we have identified 9 compounds more potent than benznidazole (Bz) among these novel arylated and hydroxylated quinones. For instance, 5-hydroxy-2-[4-(trifluoromethyl)phenyl]-1,4-naphthoquinone (4h) with an IC50/24 h value of 22.8 µM is 4.5-fold more active than the state-of-the-art drug Bz. This article provides the first example of the application of CH activation for the position-selective hydroxylation of arylated quinones and the identification of these compounds as trypanocidal drug candidates.


Asunto(s)
Oxígeno/química , Paladio/química , Quinonas/farmacología , Rutenio/química , Tripanocidas/farmacología , Trypanosoma cruzi/efectos de los fármacos , Animales , Catálisis , Enfermedad de Chagas/tratamiento farmacológico , Relación Dosis-Respuesta a Droga , Ratones , Estructura Molecular , Pruebas de Sensibilidad Parasitaria , Quinonas/síntesis química , Quinonas/química , Relación Estructura-Actividad , Tripanocidas/síntesis química , Tripanocidas/química
3.
Bioorg Med Chem ; 28(15): 115565, 2020 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-32631558

RESUMEN

Rhodium-catalyzed [2 + 2 + 2] cycloadditions, sulfonyl phthalide annulations and nitroalkene reactions have been employed for the synthesis of 56 quinone-based compounds. These were evaluated against Trypanosoma cruzi, the parasite that causes Chagas disease. The reactions described here are part of a program that aims to utilize modern, versatile and efficient synthetic methods for the one or two step preparation of trypanocidal compounds. We have identified 9 compounds with potent activity against the parasite; 3 of these were 30-fold more potent than benznidazole (Bz), a drug used for the treatment of Chagas disease. This article provides a comprehensive outline of reactions involving over 120 compounds aimed at the discovery of new quinone-based frameworks with activity against T. cruzi.


Asunto(s)
Naftoquinonas/farmacología , Tripanocidas/farmacología , Trypanosoma cruzi/efectos de los fármacos , Alquenos/química , Catálisis , Reacción de Cicloadición , Estructura Molecular , Naftoquinonas/síntesis química , Nitrocompuestos/química , Pruebas de Sensibilidad Parasitaria , Rodio/química , Relación Estructura-Actividad , Sulfonas/química , Tripanocidas/síntesis química
4.
Parasitology ; 146(8): 1075-1082, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31057143

RESUMEN

Trypanosoma cruzi is the causative agent of Chagas disease, a vector-borne disease. The parasite molecules involved in vector interaction have been little investigated. Metallopeptidases and gp63 molecules have been implicated in parasite adhesion of several trypanosomatids to the insect midgut. Although gp63 homologues are highly expanded in the T. cruzi genome, and are implicated in parasite-mammalian host interaction, its role in the insect vector has never been explored. Here, we showed that divalent metal chelators or anti-Tcgp63-I antibodies impaired T. cruzi adhesion to Rhodnius prolixus midgut. Parasites isolated after insect colonization presented a drastic enhancement in the expression of Tcgp63-I. These data highlight, for the first time, that Tcgp63-I and Zn-dependent enzymes contribute to the interaction of T. cruzi with the insect vector.


Asunto(s)
Metaloendopeptidasas/fisiología , Proteínas Protozoarias/fisiología , Rhodnius/parasitología , Trypanosoma cruzi/fisiología , Animales , Anticuerpos Antiprotozoarios/metabolismo , Enfermedad de Chagas/parasitología , Interacciones Huésped-Parásitos , Insectos Vectores/parasitología
5.
Respir Res ; 19(1): 104, 2018 05 29.
Artículo en Inglés | MEDLINE | ID: mdl-29843724

RESUMEN

BACKGROUND: Silicosis is an occupational disease that affects workers who inhale silica particles, leading to extensive lung fibrosis and ultimately causing respiratory failure. Mesenchymal stromal cells (MSCs) have been shown to exert therapeutic effects in lung diseases and represent an alternative treatment for silicosis. Recently, it has been suggested that similar effects can be achieved by the therapeutic use of extracellular vesicles (EVs) obtained from MSCs. The aim of this study was to investigate the effects of adipose-tissue-derived MSCs (AD-MSCs) or their EVs in a model of silicosis. METHODS: Silicosis was induced by intratracheal instillation of silica in C57BL/6 mice. After the onset of disease, animals received saline, AD-MSCs, or EVs, intratracheally. RESULTS: At day 30, AD-MSCs and EVs led to a reduction in collagen fiber content, size of granuloma, and in the number of macrophages inside granuloma and in the alveolar septa. In addition, the expression levels of interleukin 1ß and transforming growth factor beta in the lungs were decreased. Higher dose of EVs also reduced lung static elastance when compared with the untreated silicosis group. CONCLUSIONS: Both AD-MSCs and EVs, locally delivered, ameliorated fibrosis and inflammation, but dose-enhanced EVs yielded better therapeutic outcomes in this model of silicosis.


Asunto(s)
Tejido Adiposo/trasplante , Modelos Animales de Enfermedad , Vesículas Extracelulares/trasplante , Trasplante de Células Madre Mesenquimatosas/métodos , Dióxido de Silicio/toxicidad , Silicosis/terapia , Tejido Adiposo/citología , Animales , Femenino , Células Madre Mesenquimatosas , Ratones , Ratones Endogámicos C57BL , Silicosis/patología , Resultado del Tratamiento
6.
Chemistry ; 24(57): 15227-15235, 2018 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-29904959

RESUMEN

This work reports a combination of aryl diselenides/hydrogen peroxide and carbon-nanotube (CNT)/rhodium nanohybrids (RhCNT) for naphthol oxidation towards the synthesis of 1,4-naphthoquinones and evaluation of their relevant trypanocidal activity. Under a combination of (PhSe)2 /H2 O2 in the presence of O2 in iPrOH/hexane, several benzenoid (A-ring)-substituted quinones were prepared in moderate to high yields. We also studied the contribution of RhCNT as co-catalyst in this process and, in some cases, yields were improved. This method provides an efficient and versatile alternative for preparing A-ring-modified naphthoquinonoid compounds with relevant biological profile.


Asunto(s)
Peróxido de Hidrógeno/química , Nanotubos de Carbono/química , Naftoles/química , Naftoquinonas/síntesis química , Rodio/química , Tripanocidas/síntesis química , Enfermedad de Chagas/tratamiento farmacológico , Humanos , Peróxido de Hidrógeno/síntesis química , Modelos Moleculares , Naftoles/síntesis química , Naftoquinonas/química , Naftoquinonas/farmacología , Compuestos de Organoselenio/química , Oxidación-Reducción , Tripanocidas/química , Tripanocidas/farmacología , Trypanosoma cruzi/efectos de los fármacos
7.
Org Biomol Chem ; 16(10): 1686-1691, 2018 03 07.
Artículo en Inglés | MEDLINE | ID: mdl-29450434

RESUMEN

We report a sequential C-H iodination/organoyl-thiolation of naphthoquinones and their relevant trypanocidal activity. Under a combination of AgSR with a copper source, sulfur-substituted benzenoid quinones were prepared in high yields (generally >90%). This provides an efficient and general method for preparing A-ring modified naphthoquinoidal systems, recognized as a challenge in quinone chemistry.

8.
Parasitology ; 145(3): 355-370, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29039273

RESUMEN

The species Phytomonas serpens is known to express some molecules displaying similarity to those described in trypanosomatids pathogenic to humans, such as peptidases from Trypanosoma cruzi (cruzipain) and Leishmania spp. (gp63). In this work, a population of P. serpens resistant to the calpain inhibitor MDL28170 at 70 µ m (MDLR population) was selected by culturing promastigotes in increasing concentrations of the drug. The only relevant ultrastructural difference between wild-type (WT) and MDLR promastigotes was the presence of microvesicles within the flagellar pocket of the latter. MDLR population also showed an increased reactivity to anti-cruzipain antibody as well as a higher papain-like proteolytic activity, while the expression of calpain-like molecules cross-reactive to anti-Dm-calpain (from Drosophila melanogaster) antibody and calcium-dependent cysteine peptidase activity were decreased. Gp63-like molecules also presented a diminished expression in MDLR population, which is probably correlated to the reduction in the parasite adhesion to the salivary glands of the insect vector Oncopeltus fasciatus. A lower accumulation of Rhodamine 123 was detected in MDLR cells when compared with the WT population, a phenotype that was reversed when MDLR cells were treated with cyclosporin A and verapamil. Collectively, our results may help in the understanding of the roles of calpain inhibitors in trypanosomatids.


Asunto(s)
Inhibidores de Cisteína Proteinasa/farmacología , Dipéptidos/farmacología , Proteínas de Transporte de Membrana/efectos de los fármacos , Péptido Hidrolasas/efectos de los fármacos , Trypanosomatina/efectos de los fármacos , Calpaína/antagonistas & inhibidores , Calpaína/química , Calpaína/efectos de los fármacos , Calpaína/genética , Cisteína Endopeptidasas/inmunología , Resistencia a Medicamentos , Glicoproteínas/farmacología , Leishmania/química , Leishmania/fisiología , Proteínas de Transporte de Membrana/genética , Péptido Hidrolasas/genética , Proteínas Protozoarias/inmunología , Trypanosoma cruzi/química , Trypanosoma cruzi/fisiología , Trypanosomatina/genética
9.
Parasitology ; 143(11): 1469-78, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27312370

RESUMEN

The phenotypic activity of two 5-nitroindazolinones, i.e. 2-benzyl-1-propyl (22) and 2-benzyl-1-butyl (24) derivatives, previously proposed as anti-Trypanosoma cruzi prototypes, was presently assayed on bloodstream trypomastigotes (BT) of the moderately drug-resistant Y strain. Further exploration of putative targets and cellular mechanisms involved in their activity was also carried out. Therefore, transmission electron microscopy, high-resolution respirometry and flow cytometry procedures were performed on BT treated for up to 24 h with the respective EC50 value of each derivative. Results demonstrated that although 22 and 24 were not as active as benznidazole in this in vitro assay on BT, both compounds triggered important damages in T. cruzi that lead to the parasite death. Ultrastructural alterations included shedding events, detachment of plasma membrane and nuclear envelope, loss of mitochondrial integrity, besides the occurrence of a large number of intracellular vesicles and profiles of endoplasmic reticulum surrounding cytoplasmic organelles such as mitochondrion. Moreover, both derivatives affected mitochondrion leading to this organelle dysfunction, as reflected by the inhibition in oxygen consumption and the loss of mitochondrial membrane potential. Altogether, the findings exposed in the present study propose autophagic processes and mitochondrial machinery as part of the mode of action of both 5-nitroindazolinones 22 and 24 on T. cruzi trypomastigotes.


Asunto(s)
Indazoles/farmacología , Tripanocidas/farmacología , Trypanosoma cruzi/efectos de los fármacos , Animales , Autofagia/efectos de los fármacos , Membrana Celular/efectos de los fármacos , Enfermedad de Chagas/parasitología , Retículo Endoplásmico/efectos de los fármacos , Citometría de Flujo , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Ratones , Microscopía Electrónica de Transmisión , Mitocondrias/efectos de los fármacos , Nitroimidazoles/farmacología , Membrana Nuclear/efectos de los fármacos , Consumo de Oxígeno/efectos de los fármacos , Trypanosoma cruzi/fisiología , Trypanosoma cruzi/ultraestructura
10.
Parasitol Res ; 115(8): 3057-69, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27106236

RESUMEN

Proteasomal proteolysis is required for a wide range of cellular processes, including protein quality control, cell cycle progression, cell death and metabolic adaptation to environment changes or stress responses. Proteasome inhibitors are useful compounds for determining the roles of proteasome in eukaryotic cells. Here, we investigated the effects of gliotoxin, a proteasome inhibitor, on the cell growth, replication, ultrastructure, DNA integrity and proteasomal proteolytic activity of the protist parasite Tritrichomonas foetus. The effect of gliotoxin on the transformation of T. foetus to endoflagellar form (EFF), also known as pseudocyst, was investigated. Gliotoxin inhibited the culture growth, arrested cell cycle, and provoked a trichomonacidal effect in a dose-dependent manner. Parasites treated with gliotoxin displayed features typical of cell death, such as membrane blebbing, concentric membrane whorls containing remnants of organelles, intense cytosolic and nuclear vacuolisation, chromatin condensation, DNA fragmentation, cytoplasmic disintegration and plasma membrane disruption. The proteasomal peptidase activity was inhibited by gliotoxin in a dose-dependent manner. Gliotoxin treatment also induced an irreversible EFF transformation in a dose/time-dependent manner. We compared morphological characteristics between gliotoxin- and cold-induced EFF parasites. Our results suggest that gliotoxin could induce EFF transformation by a mechanism distinct from that provoked by cold temperature. This study further contributes to a better understanding of the role of proteasome system in cell cycle, cell death and EFF transformation in T. foetus.


Asunto(s)
Gliotoxina/farmacología , Complejo de la Endopetidasa Proteasomal/metabolismo , Inhibidores de Proteasoma/farmacología , Proteolisis/efectos de los fármacos , Tritrichomonas foetus/metabolismo , Animales , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Puntos de Control del Ciclo Celular/efectos de los fármacos , Muerte Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Fragmentación del ADN/efectos de los fármacos , Tritrichomonas foetus/efectos de los fármacos
11.
Org Biomol Chem ; 13(38): 9862-71, 2015 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-26288376

RESUMEN

Cascade reactions of amidines with nitroallylic acetates and α-bromonitroalkenes provide potentially bioactive imidazoles in good to excellent yields in most cases. While 2,4-disubstituted imidazol-5-yl acetates are formed in the first case, 2,4-disubstituted imidazoles, bearing no substituent at position 5, are the products in the second case. These two series of imidazoles, viz. 2,4,5-trisubstituted and 2,4-disubstituted, were screened for their activity against the protozoan parasite Trypanosoma cruzi which is responsible for Chagas disease. As many as three compounds were as active as the standard benznidazole and two others were 2-3-fold more active highlighting the potential of substituted imidazoles, easily accessible from nitroalkenes, as possible anti-parasitic agents.


Asunto(s)
Acetatos/química , Amidinas/química , Enfermedad de Chagas/tratamiento farmacológico , Imidazoles/química , Nitrocompuestos/química , Tripanocidas/síntesis química , Tripanocidas/farmacología , Trypanosoma cruzi/efectos de los fármacos , Animales , Enfermedad de Chagas/parasitología , Relación Dosis-Respuesta a Droga , Ratones , Estructura Molecular , Pruebas de Sensibilidad Parasitaria , Relación Estructura-Actividad
12.
Org Biomol Chem ; 13(7): 1996-2000, 2015 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-25573664

RESUMEN

A one-pot, two step synthesis of highly substituted imidazoles has been carried out in good to excellent yields for the first time via a cascade intermolecular aza-SN2'-intramolecular aza-Michael addition involving a variety of Morita-Baylis-Hillman acetates of nitroalkenes and amidines in the presence of DABCO at room temperature. The synthetic and biological utility of the products has been demonstrated. In particular, some of the imidazoles exhibited potent activity against T. cruzi, the etiological agent of Chagas disease.


Asunto(s)
Acetatos/química , Amidinas/química , Imidazoles/farmacología , Fenilbutiratos/química , Tripanocidas/farmacología , Trypanosoma cruzi/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Imidazoles/síntesis química , Imidazoles/química , Estructura Molecular , Pruebas de Sensibilidad Parasitaria , Relación Estructura-Actividad , Tripanocidas/síntesis química , Tripanocidas/química
13.
J Nat Prod ; 78(4): 880-4, 2015 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-25768915

RESUMEN

Leishmaniasis is an important neglected disease caused by protozoa of the genus Leishmania that affects more than 12 million people worldwide. Leishmaniasis treatment requires the administration of toxic and poorly tolerated drugs, and parasite resistance greatly reduces the efficacy of conventional medications. Apigenin (1), a naturally occurring plant flavone, has a wide range of reported biological effects. In this study, antileishmanial activity of 1 in vitro was investigated, and its mechanism of action against Leishmania amazonensis promastigotes was described. Treatment with 1 for 24 h resulted in concentration-dependent inhibition of cellular proliferation (IC50 = 23.7 µM) and increased reactive oxygen species (ROS) generation. Glutathione and N-acetyl-l-cysteine protected L. amazonensis from the effects of 1 and reduced ROS levels after the treatment. By contrast, oxidized glutathione did not reduce the levels of ROS caused by 1 by not preventing the proliferation inhibition. Apigenin 1 also induced an extensive swelling in parasite mitochondria, leading to an alteration of the mitochondrial membrane potential, rupture of the trans-Golgi network, and cytoplasmic vacuolization. These results demonstrate the leishmanicidal effect of 1 and suggest the involvement of ROS leading to mitochondrial collapse as part of the mechanism of action.


Asunto(s)
Antiprotozoarios/farmacología , Apigenina/farmacología , Leishmania/efectos de los fármacos , Mitocondrias/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Acetilcisteína/farmacología , Antiprotozoarios/química , Apigenina/química , Glutatión/farmacología , Humanos , Leishmaniasis/tratamiento farmacológico , Mitocondrias/efectos de los fármacos , Estructura Molecular
14.
Subcell Biochem ; 74: 305-22, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24264251

RESUMEN

Chagas disease is a neglected tropical illness endemic to Latin America, and its treatment remains unsatisfactory. This disease is caused by the hemoflagellate protozoan Trypanosoma cruzi, which has a complex life cycle involving three evolutive forms in both vertebrate and invertebrate hosts. Targeting metabolic pathways in the parasite for rational drug design represents a promising research field. This research area requires high performance techniques and proteomics become a powerful tool in this context. Here, we review advances in the construction of proteomic maps of the different forms of T. cruzi, emphasizing their biological applications towards the identification of alternative candidates for drug intervention.


Asunto(s)
Descubrimiento de Drogas , Proteómica , Proteínas Protozoarias/química , Tripanocidas/farmacología , Trypanosoma cruzi/metabolismo , Tripanocidas/química
15.
JHEP Rep ; 6(2): 100984, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38293685

RESUMEN

Background & Aims: Lipid droplet (LD) accumulation in cells and tissues is understood to be an evolutionarily conserved tissue tolerance mechanism to prevent lipotoxicity caused by excess lipids; however, the presence of excess LDs has been associated with numerous diseases. Sepsis triggers the reprogramming of lipid metabolism and LD accumulation in cells and tissues, including the liver. The functions and consequences of sepsis-triggered liver LD accumulation are not well known. Methods: Experimental sepsis was induced by CLP (caecal ligation and puncture) in mice. Markers of hepatic steatosis, liver injury, hepatic oxidative stress, and inflammation were analysed using a combination of functional, imaging, lipidomic, protein expression and immune-enzymatic assays. To prevent LD formation, mice were treated orally with A922500, a pharmacological inhibitor of DGAT1. Results: We identified that liver LD overload correlates with liver injury and sepsis severity. Moreover, the progression of steatosis from 24 h to 48 h post-CLP occurs in parallel with increased cytokine expression, inflammatory cell recruitment and oxidative stress. Lipidomic analysis of purified LDs demonstrated that sepsis leads LDs to harbour increased amounts of unsaturated fatty acids, mostly 18:1 and 18:2. An increased content of lipoperoxides within LDs was also observed. Conversely, the impairment of LD formation by inhibition of the DGAT1 enzyme reduces levels of hepatic inflammation and lipid peroxidation markers and ameliorates sepsis-induced liver injury. Conclusions: Our results indicate that sepsis triggers lipid metabolism alterations that culminate in increased liver LD accumulation. Increased LDs are associated with disease severity and liver injury. Moreover, inhibition of LD accumulation decreased the production of inflammatory mediators and lipid peroxidation while improving tissue function, suggesting that LDs contribute to the pathogenesis of liver injury triggered by sepsis. Impact and Implications: Sepsis is a complex life-threatening syndrome caused by dysregulated inflammatory and metabolic host responses to infection. The observation that lipid droplets may contribute to sepsis-associated organ injury by amplifying lipid peroxidation and inflammation provides a rationale for therapeutically targeting lipid droplets and lipid metabolism in sepsis.

16.
PLoS Pathog ; 7(3): e1001320, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21445237

RESUMEN

The presence of bacteria in the midgut of mosquitoes antagonizes infectious agents, such as Dengue and Plasmodium, acting as a negative factor in the vectorial competence of the mosquito. Therefore, knowledge of the molecular mechanisms involved in the control of midgut microbiota could help in the development of new tools to reduce transmission. We hypothesized that toxic reactive oxygen species (ROS) generated by epithelial cells control bacterial growth in the midgut of Aedes aegypti, the vector of Yellow fever and Dengue viruses. We show that ROS are continuously present in the midgut of sugar-fed (SF) mosquitoes and a blood-meal immediately decreased ROS through a mechanism involving heme-mediated activation of PKC. This event occurred in parallel with an expansion of gut bacteria. Treatment of sugar-fed mosquitoes with increased concentrations of heme led to a dose dependent decrease in ROS levels and a consequent increase in midgut endogenous bacteria. In addition, gene silencing of dual oxidase (Duox) reduced ROS levels and also increased gut flora. Using a model of bacterial oral infection in the gut, we show that the absence of ROS resulted in decreased mosquito resistance to infection, increased midgut epithelial damage, transcriptional modulation of immune-related genes and mortality. As heme is a pro-oxidant molecule released in large amounts upon hemoglobin degradation, oxidative killing of bacteria in the gut would represent a burden to the insect, thereby creating an extra oxidative challenge to the mosquito. We propose that a controlled decrease in ROS levels in the midgut of Aedes aegypti is an adaptation to compensate for the ingestion of heme.


Asunto(s)
Aedes/microbiología , Hemo/metabolismo , Hemoglobinas/metabolismo , Proteínas de Insectos/metabolismo , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo , Animales , Hemo/farmacología , Hemoglobinas/farmacología , Humanos , Conejos
17.
BMC Microbiol ; 13: 196, 2013 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-24004461

RESUMEN

BACKGROUND: Naphthoquinones (NQs) are privileged structures in medicinal chemistry due to the biological effects associated with the induction of oxidative stress. The present study evaluated the activities of sixteen NQs derivatives on Trypanosoma cruzi. RESULTS: Fourteen NQs displayed higher activity against bloodstream trypomastigotes of T. cruzi than benznidazole. Further assays with NQ1, NQ8, NQ9 and NQ12 showed inhibition of the proliferation of axenic epimastigotes and intracelulluar amastigotes interiorized in macrophages and in heart muscle cells. NQ8 was the most active NQ against both proliferative forms of T. cruzi. In epimastigotes the four NQs induced mitochondrial swelling, vacuolization, and flagellar blebbing. The treatment with NQs also induced the appearance of large endoplasmic reticulum profiles surrounding different cellular structures and of myelin-like membranous contours, morphological characteristics of an autophagic process. At IC50 concentration, NQ8 totally disrupted the ΔΨm of about 20% of the parasites, suggesting the induction of a sub-population with metabolically inactive mitochondria. On the other hand, NQ1, NQ9 or NQ12 led only to a discrete decrease of TMRE + labeling at IC50 values. NQ8 led also to an increase in the percentage of parasites labeled with DHE, indicative of ROS production, possibly the cause of the observed mitochondrial swelling. The other three NQs behaved similarly to untreated controls. CONCLUSIONS: NQ1, NQ8, NQ9 and NQ12 induce an autophagic phenotype in T. cruzi epimastigoted, as already observed with others NQs. The absence of oxidative stress in NQ1-, NQ9- and NQ12-treated parasites could be due to the existence of more than one mechanism of action involved in their trypanocidal activity, leaving ROS generation suppressed by the detoxification system of the parasite. The strong redox effect of NQ8 could be associated to the presence of the acetyl group in its structure facilitating quinone reduction, as previously demonstrated by electrochemical analysis. Further experiments using biochemical and molecular approaches are needed to better characterize ROS participation in the mechanism of action of these NQs.


Asunto(s)
Antiprotozoarios/farmacología , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Dilatación Mitocondrial , Naftoquinonas/farmacología , Trypanosoma cruzi/efectos de los fármacos , Animales , Concentración 50 Inhibidora , Macrófagos/efectos de los fármacos , Macrófagos/parasitología , Ratones , Mitocondrias/fisiología , Pruebas de Sensibilidad Parasitaria
18.
Bioorg Med Chem ; 21(21): 6337-48, 2013 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-24074878

RESUMEN

In our continued search for novel trypanocidal compounds, twenty-six derivatives of para- and ortho-naphthoquinones coupled to 1,2,3-triazoles were synthesized. These compounds were evaluated against the infective bloodstream form of Trypanosoma cruzi, the etiological agent of Chagas disease. Compounds 17-24, 28-30 and 36-38 are described herein for the first time. Three of these novel compounds (28-30) were found to be more potent than the standard drug benznidazole, with IC50/24h values between 6.8 and 80.8µM. Analysis of the toxicity to heart muscle cells led to LC50/24h of <125, 63.1 and 281.6µM for 28, 29 and 30, respectively. Displaying a selectivity index of 34.3, compound 30 will be further evaluated in vivo. The electrochemical properties of selected compounds were evaluated in an attempt to find correlations with trypanocidal activity, and it was observed that more electrophilic quinones were generally more potent.


Asunto(s)
Naftoquinonas/química , Triazoles/química , Tripanocidas/síntesis química , Animales , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Cristalografía por Rayos X , Técnicas Electroquímicas , Electrodos , Ratones , Conformación Molecular , Miocitos Cardíacos/citología , Relación Estructura-Actividad , Triazoles/síntesis química , Triazoles/toxicidad , Tripanocidas/química , Tripanocidas/toxicidad , Trypanosoma cruzi/efectos de los fármacos
19.
Pathogens ; 12(3)2023 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-36986345

RESUMEN

Phytomonas serpens is a trypanosomatid phytoparasite, found in a great variety of species, including tomato plants. It is a significant problem for agriculture, causing high economic loss. In order to reduce the vegetal infections, different strategies have been used. The biological activity of molecules obtained from natural sources has been widely investigated to treat trypanosomatids infections. Among these compounds, chalcones have been shown to have anti-parasitic and anti-inflammatory effects, being described as having a remarkable activity on trypanosomatids, especially in Leishmania species. Here, we evaluated the antiprotozoal activity of the chalcone derivative (NaF) on P. serpens promastigotes, while also assessing its mechanism of action. The results showed that treatment with the derivative NaF for 24 h promotes an important reduction in the parasite proliferation (IC50/24 h = 23.6 ± 4.6 µM). At IC50/24 h concentration, the compound induced an increase in reactive oxygen species (ROS) production and a shortening of the unique flagellum of the parasites. Electron microscopy evaluation reinforced the flagellar phenotype in treated promastigotes, and a dilated flagellar pocket was frequently observed. The treatment also promoted a prominent autophagic phenotype. An increased number of autophagosomes were detected, presenting different levels of cargo degradation, endoplasmic reticulum profiles surrounding different cellular structures, and the presence of concentric membranar structures inside the mitochondrion. Chalcone derivatives may present an opportunity to develop a treatment for the P. serpens infection, as they are easy to synthesize and are low in cost. In order to develop a new product, further studies are still necessary.

20.
Front Immunol ; 14: 1282278, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38115994

RESUMEN

Introduction: Toxoplasma gondii, responsible for causing toxoplasmosis, is a prevalent food and waterborne pathogen worldwide. It commonly infects warm-blooded animals and affects more than a third of the global human population. Once ingested, the parasite enters the host's small intestine and rapidly disseminates throughout the body via the bloodstream, infiltrating various tissues. Leukocyte-driven responses are vital against T. gondii, with neutrophils playing a dual role: swiftly recruited to infection sites, releasing inflammatory mediators, and serving as a replication hub and Trojan horses, aiding parasite spread. Neutrophils from various hosts release extracellular traps (NETs) against the protozoan. However, gaps persist regarding the mechanisms of NETs production to parasite and their significance in infection control. This study investigates the interplay between human neutrophils and T. gondii, exploring dynamics, key molecules, and signaling pathways involved in NETs production upon protozoan challenge. Methods and Results: Using confocal and electron microscopy, live cell imaging, pharmacological inhibitors, and DNA quantification assays, we find that human neutrophils promptly release both classical and rapid NETs upon pathogen stimulation. The NETs structure exhibits diverse phenotypes over time and is consistently associated with microorganisms. Mechanisms involve neutrophil elastase and peptidylarginine deiminase, along with intracellular calcium signaling and the PI3K pathway. Unexpectedly, human traps do not diminish viability or infectivity, but potentially aid in capturing parasites for subsequent neutrophil phagocytosis and elimination. Discussion: By revealing NETs formation mechanisms and their nuanced impact on T. gondii infection dynamics, our findings contribute to broader insights into host-pathogen relationships.


Asunto(s)
Trampas Extracelulares , Toxoplasma , Toxoplasmosis , Animales , Humanos , Trampas Extracelulares/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Toxoplasmosis/metabolismo , Neutrófilos/metabolismo , Toxoplasma/fisiología
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