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1.
Arq. bras. cardiol ; 117(6): 1147-1158, dez. 2021. tab, graf
Artigo em Português | LILACS | ID: biblio-1350045

RESUMO

Resumo Fundamento A doxorrubicina (DOX) é frequentemente usada para tratar muitos tipos de cânceres, apesar da cardiotoxicidade dose-dependente. Como alternativa, o resveratrol é um polifenol que tem demonstrado efeitos cardioprotetores em vários modelos de disfunção cardíaca. Objetivo Este estudo investigou se o tratamento com resveratrol em ratas gestantes protege contra toxicidade induzida por doxorrubicina em cardiomiócitos da ninhada. Métodos Ratas Wistar (n-8) receberam sresveratrol como suplemento alimentar durante a gestação. No nascimento da ninhada, os corações (9-11) foram usados para se obter a cultura primária de cardiomiócitos. A cardiotoxicidade induzida por DOX e os efeitos da suplementação com resveratrol foram avaliados por marcadores de stress oxidativo, tais como oxidação da diclorofluoresceína diacetato, diminuição da atividade de enzimas antioxidantes, e oxidação do teor total de grupos sulfidrila, além da avaliação da viabilidade celular, geração de danos ao DNA, bem como a resposta de reparo aos danos ao DNA. Um valor de p <0,05 foi considerado estatisticamente significativo. Resultados Os cardiomiócitos de neonatos de ratas que receberam suplemento resveratrol apresentaram um aumento (p <0,01) na viabilidade das células, e diminuição (p <0,0001) de células apoptóticas/necróticas após o tratamento com DOX, o que está correlacionado às atividades de enzimas antioxidantes e produção de diclorofluoresceína. Além disso, o resveratrol protegeu os cardiomiócitos de danos ao DNA induzidos por DOX, apresentando uma diminuição (p <0,05) nas quebras de DNA induzidas por stress oxidativo, avaliadas pela atividade de enzimas reparadoras do DNA endonuclease III e formamidopirimidina glicosilase. A suplementação com resveratrol aumentou (p <0,05) a expressão da proteína reparadora Sirt6 nos cardiomiócitos dos filhotes. Conclusão Essa pesquisa indica que a suplementação com resveratrol durante o período gestacional tem um efeito cardioprotetor no coração da ninhada contra a toxicidade induzida por DOX, o que pode se dever a sua função antioxidante, e o aumento na resposta de danos ao DNA.


Abstract Background Doxorubicin (DOX) is frequently used to treat many types of cancers, despite its dose-dependent cardiotoxicity. Alternatively, resveratrol is a polyphenol that has shown useful cardioprotective effects in many heart dysfunction models. Objective This study investigated whether resveratrol treatment in pregnant rats protects against doxorubicin-induced toxicity in offspring cardiomyocytes. Methods Wistar rats (n=8) were supplemented with dietary resveratrol during pregnancy. Upon the offspring's birth, hearts (9-11) were used to obtain the primary culture of cardiomyocytes. DOX-induced cardiotoxicity and the effects of resveratrol supplementation were evaluated by oxidative stress markers, such as dichlorofluorescein diacetate oxidation, decrease in the activity of antioxidant enzymes, and oxidation of total sulfhydryl content, in addition to cell viability evaluation, DNA damage generation, and DNA damage repair response. A value of p<0.05 was considered statistically significant. Results Neonatal cardiomyocytes from resveratrol supplemented rats exhibiting an increase (p<0.01) in cell viability and lower (p<0.0001) apoptotic/necrotic cells after DOX treatment, which correlates with the activities of antioxidant enzymes and dichlorofluorescein production. Moreover, resveratrol protected cardiomyocytes from DOX-induced DNA damage, showing a decrease (p<0.05) in DNA breaks induced by oxidative stress, evaluated by the activity of DNA-repair enzymes endonuclease III and formamidopyrimidine glycosylase. Supplementation with resveratrol increased (p<0.05) the expression of the repair protein Sirt6 in the cardiomyocytes of the pups. Conclusion This research indicates that supplementation with resveratrol during the gestational period has a notable cardioprotective effect on the offspring's heart against DOX-induced toxicity, which may well be due to its antioxidant function, and the increase in the DNA damage repair response.


Assuntos
Animais , Feminino , Gravidez , Ratos , Doxorrubicina/toxicidade , Miócitos Cardíacos , Ratos Wistar , Suplementos Nutricionais , Resveratrol/farmacologia
2.
Arq Bras Cardiol ; 117(6): 1147-1158, 2021 12.
Artigo em Inglês, Português | MEDLINE | ID: mdl-34644787

RESUMO

BACKGROUND: Doxorubicin (DOX) is frequently used to treat many types of cancers, despite its dose-dependent cardiotoxicity. Alternatively, resveratrol is a polyphenol that has shown useful cardioprotective effects in many heart dysfunction models. OBJECTIVE: This study investigated whether resveratrol treatment in pregnant rats protects against doxorubicin-induced toxicity in offspring cardiomyocytes. METHODS: Wistar rats (n=8) were supplemented with dietary resveratrol during pregnancy. Upon the offspring's birth, hearts (9-11) were used to obtain the primary culture of cardiomyocytes. DOX-induced cardiotoxicity and the effects of resveratrol supplementation were evaluated by oxidative stress markers, such as dichlorofluorescein diacetate oxidation, decrease in the activity of antioxidant enzymes, and oxidation of total sulfhydryl content, in addition to cell viability evaluation, DNA damage generation, and DNA damage repair response. A value of p<0.05 was considered statistically significant. RESULTS: Neonatal cardiomyocytes from resveratrol supplemented rats exhibiting an increase (p<0.01) in cell viability and lower (p<0.0001) apoptotic/necrotic cells after DOX treatment, which correlates with the activities of antioxidant enzymes and dichlorofluorescein production. Moreover, resveratrol protected cardiomyocytes from DOX-induced DNA damage, showing a decrease (p<0.05) in DNA breaks induced by oxidative stress, evaluated by the activity of DNA-repair enzymes endonuclease III and formamidopyrimidine glycosylase. Supplementation with resveratrol increased (p<0.05) the expression of the repair protein Sirt6 in the cardiomyocytes of the pups. CONCLUSION: This research indicates that supplementation with resveratrol during the gestational period has a notable cardioprotective effect on the offspring's heart against DOX-induced toxicity, which may well be due to its antioxidant function, and the increase in the DNA damage repair response.


FUNDAMENTO: A doxorrubicina (DOX) é frequentemente usada para tratar muitos tipos de cânceres, apesar da cardiotoxicidade dose-dependente. Como alternativa, o resveratrol é um polifenol que tem demonstrado efeitos cardioprotetores em vários modelos de disfunção cardíaca. OBJETIVO: Este estudo investigou se o tratamento com resveratrol em ratas gestantes protege contra toxicidade induzida por doxorrubicina em cardiomiócitos da ninhada. MÉTODOS: Ratas Wistar (n-8) receberam sresveratrol como suplemento alimentar durante a gestação. No nascimento da ninhada, os corações (9-11) foram usados para se obter a cultura primária de cardiomiócitos. A cardiotoxicidade induzida por DOX e os efeitos da suplementação com resveratrol foram avaliados por marcadores de stress oxidativo, tais como oxidação da diclorofluoresceína diacetato, diminuição da atividade de enzimas antioxidantes, e oxidação do teor total de grupos sulfidrila, além da avaliação da viabilidade celular, geração de danos ao DNA, bem como a resposta de reparo aos danos ao DNA. Um valor de p <0,05 foi considerado estatisticamente significativo. RESULTADOS: Os cardiomiócitos de neonatos de ratas que receberam suplemento resveratrol apresentaram um aumento (p <0,01) na viabilidade das células, e diminuição (p <0,0001) de células apoptóticas/necróticas após o tratamento com DOX, o que está correlacionado às atividades de enzimas antioxidantes e produção de diclorofluoresceína. Além disso, o resveratrol protegeu os cardiomiócitos de danos ao DNA induzidos por DOX, apresentando uma diminuição (p <0,05) nas quebras de DNA induzidas por stress oxidativo, avaliadas pela atividade de enzimas reparadoras do DNA endonuclease III e formamidopirimidina glicosilase. A suplementação com resveratrol aumentou (p <0,05) a expressão da proteína reparadora Sirt6 nos cardiomiócitos dos filhotes. CONCLUSÃO: Essa pesquisa indica que a suplementação com resveratrol durante o período gestacional tem um efeito cardioprotetor no coração da ninhada contra a toxicidade induzida por DOX, o que pode se dever a sua função antioxidante, e o aumento na resposta de danos ao DNA.


Assuntos
Doxorrubicina , Miócitos Cardíacos , Animais , Suplementos Nutricionais , Doxorrubicina/toxicidade , Feminino , Gravidez , Ratos , Ratos Wistar , Resveratrol/farmacologia
3.
Metab Brain Dis ; 36(7): 1957-1968, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34216350

RESUMO

Although phenylalanine (Phe) is known to be neurotoxic in phenylketonuria (PKU), its exact pathogenetic mechanisms of brain damage are still poorly known. Furthermore, much less is known about the role of the Phe derivatives phenylacetic (PAA), phenyllactic (PLA) and phenylpyruvic (PPA) acids that also accumulate in this this disorder on PKU neuropathology. Previous in vitro and in vivo studies have shown that Phe elicits oxidative stress in brain of rodents and that this deleterious process also occurs in peripheral tissues of phenylketonuric patients. In the present study, we investigated whether Phe and its derivatives PAA, PLA and PPA separately or in combination could induce reactive oxygen species (ROS) formation and provoke DNA damage in C6 glial cells. We also tested the role of L-carnitine (L-car), which has been recently considered an antioxidant agent and easily cross the blood brain barrier on the alterations of C6 redox status provoked by Phe and its metabolites. We first observed that cell viability was not changed by Phe and its metabolites. Furthermore, Phe, PAA, PLA and PPA, at concentrations found in plasma of PKU patients, provoked marked DNA damage in the glial cells separately and when combined. Of note, these effects were totally prevented (Phe, PAA and PPA) or attenuated (PLA) by L-car pre-treatment. In addition, a potent ROS formation also induced by Phe and PAA, whereas only moderate increases of ROS were caused by PPA and PLA. Pre-treatment with L-car also prevented Phe- and PAA-induced ROS generation, but not that provoked by PLA and PPA. Thus, our data show that Phe and its major metabolites accumulated in PKU provoke extensive DNA damage in glial cells probably by ROS formation and that L-car may potentially represent an adjuvant therapeutic agent in PKU treatment.


Assuntos
Lesões Encefálicas , Fenilcetonúrias , Lesões Encefálicas/tratamento farmacológico , Carnitina/farmacologia , Carnitina/uso terapêutico , Humanos , Cetoácidos/farmacologia , Estresse Oxidativo , Fenilalanina/farmacologia , Fenilalanina/uso terapêutico
4.
Vet Parasitol Reg Stud Reports ; 24: 100561, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-34024377

RESUMO

American visceral leishmaniasis (AVL) is a zoonosis caused by protozoan parasites of the genus Leishmania. In Brazil, the disease is caused by Leishmania infantum and the main vector is the phlebotomine sandfly Lutzomyia longipalpis, found both in natural ecotopes and in the rural and urban environments, being very well adapted to the peridomestic environment. The domestic dog has been incriminated as the main reservoir of the parasite in the urban environment, but the control measures based on culling seropositive dogs have not shown to be effective to contain the spread of the disease throughout the country. Many studies evaluated risk factors for human visceral leishmaniasis but few focused on the socioeconomic and environmental factors associated with infection among dogs. Knowledge of these factors might help identify the conditions that contribute to the maintenance of transmission cycles in the urban environment and identify new targets for intervention. The objective of this study was to assess the association between socioeconomic and environmental factors and the occurrence of canine leishmaniasis at Teresina city, Brazil. This cross-sectional study was developed in ten districts of Teresina, involving 532 houses and 810 dogs. Peripheral blood samples were collected by vein punction using vacutainer tubes without anticoagulant for performing serological test (indirect immunofluorescence - IFI). Serum samples with IFI titers ≥1: 80 were considered positive. Owners of the selected dwellings were interviewed using a semi-structured questionnaire addressing socioeconomic and environment aspects. The association between variables and seropositivity was assessed through multilevel logistic regression models. Global seropositivity was 39%. There was no statistically significant difference between seropositivity and age and sex of animals, literacy of the household head, presence of other domestic animals or with household characteristic like water supply, inadequate sewage disposal system, type of floor and roof. Mixed-breed dogs and those living for a long time in houses with absence of masonry walls and presence of a kennel showed higher odds of seropositivity. These results suggest that some peridomestic characteristics, especially the absence of barriers that allow dogs to have free access to the street, in association with the presence of a kennel, might contribute to maintaining the infection cycle in urban areas. Intervention measures oriented to the management of the peridomestic environment and responsible dog possession could be useful tools for reducing disease burden in endemic area.


Assuntos
Doenças do Cão , Leishmania infantum , Leishmaniose Cutânea , Psychodidae , Animais , Brasil/epidemiologia , Estudos Transversais , Doenças do Cão/parasitologia , Cães , Humanos , Leishmaniose Cutânea/veterinária , Psychodidae/parasitologia , Fatores Socioeconômicos
5.
Adv Nutr ; 11(5): 1211-1220, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32597926

RESUMO

The association between FokI polymorphism in the vitamin D receptor (VDR) gene and susceptibility to arterial hypertension (HT) is controversial. Thus, we evaluated the relation between FokI and HT according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using MEDLINE® (Medical Literature Analysis and Retrieval System Online)/PubMed, Scopus, and Cochrane Library CENTRAL databases. Data from case-control studies, including the number of participants, age, 25-hydroxyvitamin D concentrations, systolic and diastolic blood pressure values, FokI allele, and genotype frequency were extracted by 2 independent authors and OR was calculated with the 95% CI to assess the strength of the association between the FokI variant and odds of HT. In general and subgroup analyses, we used allelic (f compared with F), common (ff compared with FF + Ff), risk (ff + Ff compared with FF), and additive (ff compared with FF) models. Six case-control studies including 3140 cases and 3882 controls were reviewed in the meta-analysis. Global assessment revealed a correlation between FokI and reduced odds of HT in the additive/homozygote model (ff compared with FF; OR: 0.65; 95% CI: 0.45-0.94) and common/recessive model (ff compared with FF + Ff; OR: 0.75; 95% CI: 0.57-0.99). In Asian subjects, there was a significant reduction in the odds of HT in additive (ff compared with FF; OR: 0.84; 95% CI: 0.73-0.98) and risk models (ff + Ff compared with FF; OR: 0.87, 95% CI: 0.78-0.97), in particular, for Indians (South). In Africans, the statistically significant association occurred in the additive and common models. Allele f in the FokI polymorphism of the VDR gene was associated with reduced odds of HT in the general population based on the risk model. Thus, nutritional genomics can help understand the influence of nutrition on metabolic homeostasis pathways and the clinical consequences of hypertension. This study shows the need for healthy, anti-inflammatory, and antioxidant compounds to prevent or treat chronic complications.


Assuntos
Hipertensão , Receptores de Calcitriol , Adulto , Povo Asiático , Estudos de Casos e Controles , Predisposição Genética para Doença , Humanos , Hipertensão/genética , Polimorfismo Genético , Receptores de Calcitriol/genética
6.
Rev. chil. nutr ; 47(1): 141-147, feb. 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1092754

RESUMO

The objective of this review was to investigate the effect of vitamin D3 supplementation on serum 25-hydroxyvitamin D concentration in individuals with single-nucleotide polymorphisms in the vitamin D receptor gene. The research was conducted on 241 articles found in the PubMed, Scopus, Science Direct, and Cochrane Library databases between November and December 2018. After article screening, three randomized double-blind placebo-controlled clinical trials were identified as eligible for this review. Participants were Australian, Brazilian, and Chinese individuals, who ingested doses of vitamin D3 ranging from 2000 IU to a megadose of 200,000 IU. The presence of the BB/Bb genotype of the BsmI polymorphism and the FokI G allele caused an increase in the serum concentrations of vitamin D after supplementation. Nonetheless, the few studies on this subject are not unanimous in their results. It is possible that differences among populations, sample sizes, doses, and time of supplementation have an impact on data and outcomes.


El objetivo de esta revisión fue investigar el efecto de la suplementación con vitamina D3 sobre la concentración sérica de 25-hidroxivitamina D en individuos con los polimorfismos de un solo nucleótido en el gen del receptor de la vitamina D. La investigación se realizó en 241 artículos encontrados en las bases de datos PubMed, Scopus, Science Direct y Cochrane Library entre noviembre y diciembre de 2018. Después de la selección del artículo, se identificaron tres ensayos clínicos aleatorios, controlados con placebo, doble ciego, como elegibles para esta revisión. Los participantes fueron australianos, brasileños y chinos, quienes ingirieron dosis de vitamina D3 que iban desde las 2000 UI hasta una megadosis de 200,000 UI. La presencia del genotipo BB / Bb del polimorfismo BsmI y el alelo FokI G causó un aumento en las concentraciones séricas de vitamina D después de la suplementación. No obstante, los pocos estudios sobre este tema no son unánimes en sus resultados. Es posible que las diferencias entre poblaciones, tamaños de muestra, dosis y tiempo de suplementación tengan un impacto en los datos y resultados de la investigación.


Assuntos
Humanos , Vitamina D/sangue , Receptores de Calcitriol/genética , Colecalciferol/administração & dosagem , Polimorfismo Genético , Colecalciferol/farmacologia
7.
Vaccine X ; 4: 100048, 2020 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-31891152

RESUMO

There is little evidence that current control strategies for canine leishmaniosis (CanL), the veterinary disease caused by L. infantum infection, are having a positive impact. This is of critical importance because dogs are a primary reservoir for L. infantum and a significant source of parasite transmission to humans. Drugs intended primarily for human use are prohibited for the treatment of CanL because of concerns over the propagation of resistant parasites. Although allopurinol effectively decreases parasite burden in CanL the treatment needs to be maintained for life. We hypothesized that during the allopurinol-induced parasite reduction dogs may become capable of developing a more robust immune response that may permit more effective control of parasites. To test this, we investigated the clinical and parasitological impact of short-term treatment with allopurinol, either alone or in combination with a defined subunit vaccine, on dogs naturally infected with L. infantum. A total of 28 dogs were distributed as follows: untreated; oral allopurinol alone (20 mg/kg, once each day for 90 days); or allopurinol with immunization with the Leish-F2 antigen formulated with the Toll-like receptor (TLR) 4 agonist Second generation Lipid Adjuvant (SLA) in stable emulsion (SE; SLA-SE). Dogs that did not receive treatment had a progressive decline in their clinical condition and an increase in their infection levels, while treatment with allopurinol alone alleviated the clinical symptoms of CanL but did not generate sustained reduction in parasites. Concomitant immunization with Leish-F2 + SLA-SE, however, improved clinical condition while also providing long-term clearance of L. infantum from lymphoid tissues and systemic organs. These results have important implications for both the management of CanL and for limiting L. infantum transmission to humans.

8.
Parasite Epidemiol Control ; 8: e00126, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31832561

RESUMO

Serodiagnosis of Leishmania infantum infection in dogs relies on the detection of antibodies against leishmanial crude extracts or parasitic defined antigens. The expansion of canine leishmaniasis from geographical areas of Brazil in which the infection is endemic to regions in which the disease is emerging is occurring. This fact makes necessary the analysis of the serodiagnostic capabilities of different leishmanial preparations in distinct geographical locations. In this article sera from dogs infected with Leishmania and showing the clinical form of the disease, were collected in three distinct Brazilian States and were tested against soluble leishmanial antigens or seven parasite individual antigens produced as recombinant proteins. We show that the recognition of soluble leishmanial antigens by sera from these animals was influenced by the geographical location of the infected dogs. Efficacy of the diagnosis based on this crude parasite preparation was higher in newly endemic regions when compared with areas of high disease endemicity. We also show that the use of three of the recombinant proteins, namely parasite surface kinetoplastid membrane protein of 11 kDa (KMP-11), and two members of the P protein family (P2a and P0), can improve the degree of sensitivity without adversely affecting the specificity of the diagnostic assays for canine leishmaniasis, independently of the geographical area of residence. In addition, sera from dogs clinically healthy but infected were also assayed with some of the antigen preparations. We demonstrate that the use of these proteins can help to the serodiagnosis of Leishmania infected animals with subclinical infections. Finally, we propose a diagnostic protocol using a combination of KMP-11, P2a y P0, together with total leishmanial extracts.

10.
Curr Mol Pharmacol ; 11(2): 162-169, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-28969582

RESUMO

BACKGROUND AND OBJECTIVE: Gamma-decanolactone (GD) is a monoterpene effective against seizures induced by pentylenetetrazole. The mechanism of action of GD is likely to be via glutamate antagonism. GD also inhibits intracellular reactive oxygen species (ROS) generation and the lipopolysaccharide-induced expression of inducible nitric oxide synthase (iNOS) and tumor necrosis factor-alpha (TNF-α) in vitro. Considering the neuropharmacological profile of GD studied so far, we investigated the effect of intraperitoneal administration of GD 100 and 300 mg/kg on pilocarpine (PIL)-induced status epilepticus (SE) in mice. METHODS: GD was administered 30 min before PIL. Behavioral (latency to first seizure and the percentage of clonic forelimb seizures), biochemical, and oxidative stress parameters were evaluated. DNA damage in the cerebral cortex of mice was assessed using the comet assay and mutagenic activity of GD was evaluated using Salmonella/microsome assay in TA100, TA98, TA97a, TA102, and TA1535 strains, with and without metabolic activation (S9 mix). RESULTS: The behavioral results showed that only the latency to the first clonic seizure increased in the groups treated with GD 300 mg/kg, but not when the animals received GD 100 mg/kg. Both GD doses were able to increase superoxide dismutase and catalase activities, inducing a decrease in ROS and nitrite production and in DNA damage in the cerebral cortex. GD was not able to induce base pair substitution and frameshift mutations in the absence or in the presence of metabolic activation. CONCLUSION: These findings demonstrate that GD does not improve behavioral parameters in the PIL model, but it was able to protect seizure-related oxidative stress and DNA damage in mice, without inducing gene mutations.


Assuntos
Lactonas/uso terapêutico , Convulsões/tratamento farmacológico , Animais , Catalase/metabolismo , Dano ao DNA , Lactonas/farmacologia , Masculino , Camundongos , Mutagênese/genética , Óxido Nítrico/biossíntese , Estresse Oxidativo/efeitos dos fármacos , Pilocarpina , Espécies Reativas de Oxigênio/metabolismo , Salmonella typhimurium/fisiologia , Convulsões/induzido quimicamente , Convulsões/patologia , Superóxido Dismutase/metabolismo
11.
HU rev ; 44(3): 401-410, 2018.
Artigo em Português | LILACS | ID: biblio-1048110

RESUMO

Atualmente, muitas das vacinas em desenvolvimento são aquelas compostas de proteínas antigênicas individuais de parasitas ou uma combinação de vários antígenos individuais que são produzidos como produtos recombinantes obtidos por técnicas de biologia molecular. Dentre elas a Leish-111f e sua variação Leish-110f tem ganhado destaque na proteção contra a LV e LC e alcançaram estudos de fase II em seres humanos. A eficácia de uma vacina é otimizada pela adição de adjuvantes imunológicos. No entanto, embora os adjuvantes tenham sido usados por mais de um século, até o momento, apenas alguns adjuvantes são aprovados para o uso em humanos, a maioria destinada a melhorar a eficácia da vacina e a produção de anticorpos protetores específicos do antígeno. os mecanismos de ação dos adjuvantes imunológicos são diversos, dependendo da sua natureza química e molecular sendo capazes de ativar células imunes especificas que conduzem a respostas imunes inatas e adaptativas melhoradas. embora o mecanismo de ação molecular detalhado de muitos adjuvantes ainda seja desconhecido, a descoberta de receptores Toll-like (TLrs) forneceu informações críticas sobre o efeito imunoestimulador de numerosos componentes bacterianos que envolvem interação com receptores TLrs, mostrando que estes ligantes melhoram tanto a qualidade como a quantidade de respostas imunes adaptativas do hospedeiro quando utilizadas em formulações de vacinais direcionadas para doenças. o potencial desses adjuvantes de TLr em melhorar o design e os resultados de várias vacinas está em constante evolução, à medida que novos agonistas são descobertos e testados em modelos experimentais e estudos clínicos de vacinação. Nesta revisão, é apresentado um resumo do progresso recente no desenvolvimento de proteínas recombinantes de segunda geração e adjuvantes de TLr, sendo o foco principal nos TLr4 e suas melhorias.


many of the vaccines in development are currently composed of individual antigenic proteins from parasites or a combination of several individual antigens that are produced as recombinant products obtained by molecular biology techniques. Among them, Leish-111f and its Leish-110f variation have gained prominence in protection against LV and LC and already have Phase II clinical trials in humans. The efficacy of a vaccine is optimized by the addition of immunological adjuvants. However, although adjuvants have been used for more than a century, until present date, only a few adjuvants are approved for use in humans, most intended to improve vaccine efficacy, the production of antigen-specific protective antibodies and an appropriate cell-immune response. The mechanisms of action of immunological adjuvants are diverse depending on their chemical and molecular nature being able to activate specific immune cells leading to improved innate and adaptive immune responses. Although the molecular mechanism of action of many adjuvants is still unknown, the discovery of Toll-like receptors (TLrs) has provided critical information on the immunostimulatory effect of numerous bacterial components involving interaction with TLr showing that these ligands improve both the quality as the amount of host adaptive immune responses when used in vaccine formulations. The potential of these TLr adjuvants in improving the design and results of many vaccines is in constantly evolution as new molecules agonists are discovered and tested in experimental models and clinical trials as well. In this review, a summary of recent progress in the development of second generation recombinant proteinsand adjuvants of TLr is presented, being the main focus in TLr4 and its improvements.


Assuntos
Adjuvantes Imunológicos , Proteínas Recombinantes , Vacinas , Imunoterapia , Leishmaniose Visceral , Anticorpos , Formação de Anticorpos
12.
Mem Inst Oswaldo Cruz ; 112(1): 53-63, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-28076469

RESUMO

Canine visceral leishmaniasis (CVL) diagnosis is still a challenge in endemic areas with limited diagnostic resources. This study proposes a score with the potential to distinguish positive CVL cases from negative ones. We studied 265 dogs that tested positive for CVL on ELISA and parasitological tests. A score ranging between 0 and 19 was recorded on the basis of clinical signs. Dogs with CVL had an overall higher positivity of the majority of clinical signs than did dogs without CVL or with ehrlichiosis. Clinical signs such as enlarged lymph nodes (83.93%), muzzle/ear lesions (55.36%), nutritional status (51.79%), bristle condition (57.14%), pale mucosal colour (48.21%), onychogryphosis (58.93%), skin lesion (39.28%), bleeding (12.50%), muzzle depigmentation (41.07%), alopecia (39.29%), blepharitis (21.43%), and keratoconjunctivitis (42.86%) were more frequent in dogs with CVL than in dogs with ehrlichiosis or without CVL. Moreover, the clinical score increased according to the positivity of all diagnostic tests (ELISA, p < 0.001; parasite culture, p = 0.0021; and smear, p = 0.0003). Onychogryphosis (long nails) [odds ratio (OR): 3.529; 95% confidence interval (CI): 1.832-6.796; p < 0.001], muzzle depigmentation (OR: 4.651; 95% CI: 2.218-9.750; p < 0.001), and keratoconjunctivitis (OR: 5.400; 95% CI: 2.549-11.441; p < 0.001) were highly associated with CVL. Interestingly, a score cut-off value ≥ 6 had an area under the curve of 0.717 (p < 0.0001), sensitivity of 60.71%, and specificity of 73.64% for CVL diagnosis. The clinical sign-based score for CVL diagnosis suggested herein can help veterinarians reliably identify dogs with CVL in endemic areas with limited diagnostic resources.


Assuntos
Anticorpos Antiprotozoários/sangue , Doenças do Cão/diagnóstico , Leishmania infantum/imunologia , Leishmaniose Visceral/veterinária , Animais , Brasil/epidemiologia , Doenças do Cão/epidemiologia , Cães , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/epidemiologia , Masculino , Sensibilidade e Especificidade
13.
Mem. Inst. Oswaldo Cruz ; 112(1): 53-63, Jan. 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-841749

RESUMO

Canine visceral leishmaniasis (CVL) diagnosis is still a challenge in endemic areas with limited diagnostic resources. This study proposes a score with the potential to distinguish positive CVL cases from negative ones. We studied 265 dogs that tested positive for CVL on ELISA and parasitological tests. A score ranging between 0 and 19 was recorded on the basis of clinical signs. Dogs with CVL had an overall higher positivity of the majority of clinical signs than did dogs without CVL or with ehrlichiosis. Clinical signs such as enlarged lymph nodes (83.93%), muzzle/ear lesions (55.36%), nutritional status (51.79%), bristle condition (57.14%), pale mucosal colour (48.21%), onychogryphosis (58.93%), skin lesion (39.28%), bleeding (12.50%), muzzle depigmentation (41.07%), alopecia (39.29%), blepharitis (21.43%), and keratoconjunctivitis (42.86%) were more frequent in dogs with CVL than in dogs with ehrlichiosis or without CVL. Moreover, the clinical score increased according to the positivity of all diagnostic tests (ELISA, p < 0.001; parasite culture, p = 0.0021; and smear, p = 0.0003). Onychogryphosis (long nails) [odds ratio (OR): 3.529; 95% confidence interval (CI): 1.832-6.796; p < 0.001], muzzle depigmentation (OR: 4.651; 95% CI: 2.218-9.750; p < 0.001), and keratoconjunctivitis (OR: 5.400; 95% CI: 2.549-11.441; p < 0.001) were highly associated with CVL. Interestingly, a score cut-off value ≥ 6 had an area under the curve of 0.717 (p < 0.0001), sensitivity of 60.71%, and specificity of 73.64% for CVL diagnosis. The clinical sign-based score for CVL diagnosis suggested herein can help veterinarians reliably identify dogs with CVL in endemic areas with limited diagnostic resources.


Assuntos
Animais , Masculino , Feminino , Cães , Leishmania infantum/imunologia , Doenças do Cão/diagnóstico , Doenças do Cão/epidemiologia , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/veterinária , Leishmaniose Visceral/epidemiologia , Antígenos de Protozoários/sangue , Brasil/epidemiologia , Ensaio de Imunoadsorção Enzimática/veterinária , Sensibilidade e Especificidade , Anticorpos
14.
Toxicology ; 368-369: 46-57, 2016 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-27565713

RESUMO

Cancer treatment with Doxorubicin (DOX) is limited due its dose-dependent cardiotoxicity, mainly related to the oxidative stress production. In experimental models of DOX treatment exercise can be used as a beneficial adjuvant therapy. This work aimed to investigate the effects of exercise during pregnancy on DOX-induced cardiotoxicity in cardiomyocytes of progeny, examining the possible intergenerational cardioprotective effects of maternal exercise. For this purpose pregnant rats were divided in control and exercise groups and pre-treated during gestational days. Hearts of newborns were used to obtain a culture of cardiomyocytes to be treated with DOX for analyses of cell viability, apoptosis and necrosis; ROS production; DNA damage; SOD and CAT activities; and Sirt6 protein expression. The results showed that exercise during pregnancy induced an increase in the viability of neonatal cardiomyocytes and a decrease in DOX-induced apoptotic and necrotic death which were correlated to the decrease in ROS production and an increase in antioxidant defenses. Exercise also protected neonatal cardiomyocytes from DOX-induced DNA damage, demonstrating a reduction in the oxidative DNA breaks. Likewise, exercise induced an increase in expression of Sirt6 in neonatal cardiomyocytes. Therefore, these results demonstrate for the first time that exercise performed by mothers protects the neonatal heart against DOX-induced toxicity. Our data demonstrate the intergenerational effect of exercise in cardiomyocytes of progeny, where the modulation of oxidative stress through antioxidant enzymes, and DNA integrity via Sirt6, were induced due to exercise in mothers, increasing the resistance of the neonatal heart against DOX toxicity.


Assuntos
Cardiotoxicidade/prevenção & controle , Doxorrubicina/toxicidade , Coração/efeitos dos fármacos , Condicionamento Físico Animal , Animais , Animais Recém-Nascidos , Apoptose/efeitos dos fármacos , Cardiotoxicidade/etiologia , Catalase/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Feminino , Coração/fisiologia , Miócitos Cardíacos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Gravidez , Ratos , Espécies Reativas de Oxigênio/metabolismo , Sirtuínas/genética , Sirtuínas/metabolismo , Superóxido Dismutase/metabolismo
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