Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 179
Filtrar
Mais filtros

Coleção SES
Intervalo de ano de publicação
1.
Nat Immunol ; 21(7): 766-776, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32424367

RESUMO

Tissue-resident memory T (TRM) cells, functionally distinct from circulating memory T cells, have a critical role in protective immunity in tissues, are more efficacious when elicited after vaccination and yield more effective antitumor immunity, yet the signals that direct development of TRM cells are incompletely understood. Here we show that type 1 regulatory T (Treg) cells, which express the transcription factor T-bet, promote the generation of CD8+ TRM cells. The absence of T-bet-expressing type 1 Treg cells reduces the presence of TRM cells in multiple tissues and increases pathogen burden upon infectious challenge. Using infection models, we show that type 1 Treg cells are specifically recruited to local inflammatory sites via the chemokine receptor CXCR3. Close proximity with effector CD8+ T cells and Treg cell expression of integrin-ß8 endows the bioavailability of transforming growth factor-ß in the microenvironment, thereby promoting the generation of CD8+ TRM cells.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Comunicação Celular/imunologia , Diferenciação Celular/imunologia , Memória Imunológica , Linfócitos T Reguladores/imunologia , Transferência Adotiva , Animais , Linfócitos T CD8-Positivos/transplante , Coccidiose/imunologia , Coccidiose/parasitologia , Modelos Animais de Doenças , Eimeria/imunologia , Feminino , Humanos , Cadeias beta de Integrinas/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Receptores CXCR3/metabolismo , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismo , Linfócitos T Reguladores/metabolismo , Linfócitos T Reguladores/transplante , Fator de Crescimento Transformador beta/metabolismo
2.
Immunity ; 54(1): 53-67.e7, 2021 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-33058782

RESUMO

Several classes of antibiotics have long been known to have beneficial effects that cannot be explained strictly on the basis of their capacity to control the infectious agent. Here, we report that tetracycline antibiotics, which target the mitoribosome, protected against sepsis without affecting the pathogen load. Mechanistically, we found that mitochondrial inhibition of protein synthesis perturbed the electron transport chain (ETC) decreasing tissue damage in the lung and increasing fatty acid oxidation and glucocorticoid sensitivity in the liver. Using a liver-specific partial and acute deletion of Crif1, a critical mitoribosomal component for protein synthesis, we found that mice were protected against sepsis, an observation that was phenocopied by the transient inhibition of complex I of the ETC by phenformin. Together, we demonstrate that mitoribosome-targeting antibiotics are beneficial beyond their antibacterial activity and that mitochondrial protein synthesis inhibition leading to ETC perturbation is a mechanism for the induction of disease tolerance.


Assuntos
Antibacterianos/uso terapêutico , Doxiciclina/uso terapêutico , Fígado/imunologia , Pulmão/imunologia , Mitocôndrias/metabolismo , Sepse/tratamento farmacológico , Tetraciclina/uso terapêutico , Animais , Proteínas de Ciclo Celular/genética , Modelos Animais de Doenças , Transporte de Elétrons , Células Hep G2 , Humanos , Metabolismo dos Lipídeos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
3.
Cephalalgia ; 44(4): 3331024241247845, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38676534

RESUMO

BACKGROUND: Cluster headache is a primary headache disorder characterized by bouts with circadian and circannual patterns. The CLOCK gene has a central role in regulating circadian rhythms. Here, we investigate the circannual CLOCK expression in a population of cluster headache patients in comparison to matched controls. METHODS: Patients with cluster headache were sampled two to four times over at least one year, both in or outside bouts, one week after each solstice and equinox. The expression of CLOCK was measured by quantitative real-time polymerase chain reaction (RT-PCR) in the peripheral blood. RESULTS: This study included 50 patients and 58 matched controls. Among the patient population, composed of 42/50 males (84%) with an average age of 44.6 years, 45/50 (90%) suffered from episodic cluster headache. Two to four samples were collected from each patient adding up to 161 samples, 36 (22.3%) of which were collected within a bout. CLOCK expression for cluster headache patients was considerably different from that of the control population in winter (p-value mean = 0.006283), spring (p-value mean = 0.000006) and summer (p-value mean = 0.000064), but not in autumn (p-value mean = 0.262272). For each season transition, the variations in CLOCK expression were more pronounced in the control group than in the cluster headache population. No statistically significant differences were found between bout and non-bout samples. No individual factors (age, sex, circadian chronotype, smoking and coffee habits or history of migraine) were related to CLOCK expression. CONCLUSIONS: We observed that CLOCK expression in cluster headache patients fluctuates less throughout the year than in the control population. Bout activity and lifestyle factors do not seem to influence CLOCK expression.


Assuntos
Proteínas CLOCK , Cefaleia Histamínica , Humanos , Cefaleia Histamínica/genética , Masculino , Feminino , Adulto , Proteínas CLOCK/genética , Proteínas CLOCK/biossíntese , Pessoa de Meia-Idade , Ritmo Circadiano , Estações do Ano
4.
Proc Natl Acad Sci U S A ; 118(27)2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34187898

RESUMO

An acute increase in the circulating concentration of glucocorticoid hormones is essential for the survival of severe somatic stresses. Circulating concentrations of GDF15, a hormone that acts in the brain to reduce food intake, are frequently elevated in stressful states. We now report that GDF15 potently activates the hypothalamic-pituitary-adrenal (HPA) axis in mice and rats. A blocking antibody to the GDNF-family receptor α-like receptor completely prevented the corticosterone response to GDF15 administration. In wild-type mice exposed to a range of stressful stimuli, circulating levels of both corticosterone and GDF15 rose acutely. In the case of Escherichia coli or lipopolysaccharide injections, the vigorous proinflammatory cytokine response elicited was sufficient to produce a near-maximal HPA response, regardless of the presence or absence of GDF15. In contrast, the activation of the HPA axis seen in wild-type mice in response to the administration of genotoxic or endoplasmic reticulum toxins, which do not provoke a marked rise in cytokines, was absent in Gdf15-/- mice. In conclusion, consistent with its proposed role as a sentinel hormone, endogenous GDF15 is required for the activation of the protective HPA response to toxins that do not induce a substantial cytokine response. In the context of efforts to develop GDF15 as an antiobesity therapeutic, these findings identify a biomarker of target engagement and a previously unrecognized pharmacodynamic effect, which will require monitoring in human studies.


Assuntos
Fator 15 de Diferenciação de Crescimento/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipófise-Suprarrenal/metabolismo , Animais , Cisplatino/administração & dosagem , Cisplatino/farmacologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Receptores de Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Glucocorticoides/metabolismo , Fator 15 de Diferenciação de Crescimento/administração & dosagem , Humanos , Lipopolissacarídeos , Camundongos , Ratos , Tunicamicina/farmacologia
5.
Mem Inst Oswaldo Cruz ; 119: e220242, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38198296

RESUMO

BACKGROUND: Eosinophils are granulocytes that rapidly increase frequency in the bloodstream during helminthic infections and allergic responses. They are found in tissue infected by Leishmania during early disease, but their role during infection is not entirely understood. OBJECTIVES: We aim to compare the disease due to Leishmania amazonensis in BALB/c and Δdbl-GATA1 mice, which lack eosinophils. METHODS: BALB/c and Δdbl-GATA1 mice infected with L. amazonensis were observed for several weeks. The parasite load and dissemination pattern were assessed. FINDINGS: The Δdbl-GATA1 mice developed an anticipated dissemination of L. amazonensis and a worsening disease. No differences were found in the lesion development or the parasite load in the footpad among Δdbl-GATA1 mice and BALB/c eight weeks after infection. However, nine weeks after infection, massive growth of metastatic lesions appeared in several parts of the skin in Δdbl-GATA1 mice, weeks earlier than BALB/c. We observed increased parasites in the bloodstream, probably an essential dissemination route. Thirteen weeks after infection, metastatic lesions were found in all Δdbl-GATA1 mice. MAIN CONCLUSION: These results suggest a protective role of eosinophils in delaying the disease caused by L. amazonensis, although several limitations of this mice strain must be considered.


Assuntos
Leishmania mexicana , Leishmania , Animais , Camundongos , Eosinófilos , Carga Parasitária , Pele
6.
Biochem Biophys Res Commun ; 650: 21-29, 2023 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-36764209

RESUMO

Atherosclerosis is characterized by the accumulation of lipid-laden cells in the arterial walls, resulting from dysregulation of cholesterol homeostasis in the macrophage, triggered by oxidized low-density lipoprotein (oxLDL). Previous studies have shown that fucoidan, a sulfated polysaccharide from brown seaweeds, has several atheroprotective activities, however, the mechanism of fucoidan protection is not fully understood. Thus, we investigated the effect of fucoidan on atherogenesis in apolipoprotein E-deficient (ApoE-/-) mice, on oxLDL uptake by macrophages, and on the expression of the flux-associated scavenger receptors by macrophages. Also, we examined the absorption and biodistribution of orally administered fucoidan. ApoE-/- mice fed on a cholesterol-rich diet supplemented with 1% fucoidan showed reduced dyslipidemia and atherosclerosis. Fucoidan was detected in blood and peripheral tissue after gavage, suggesting that it can exert direct systemic effects. In vitro, fucoidan reduced macrophage oxLDL uptake, which resulted in lower foam cell formation. This effect was associated with downregulation of the cholesterol influx-associated scavenger receptor (SR)-A expression, and upregulation of the cholesterol efflux-associated SR-B1 expression. In conclusion, fucoidan prevented oxLDL-mediated foam cell formation in macrophages by downregulating SR-A1/2 and by up-regulating SR-B1.


Assuntos
Aterosclerose , Células Espumosas , Camundongos , Animais , Células Espumosas/metabolismo , Distribuição Tecidual , Camundongos Knockout para ApoE , Macrófagos/metabolismo , Colesterol/metabolismo , Lipoproteínas LDL/metabolismo , Polissacarídeos/metabolismo , Aterosclerose/metabolismo , Receptores Depuradores/metabolismo , Apolipoproteínas E/metabolismo
7.
Proc Natl Acad Sci U S A ; 117(22): 12281-12287, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32424099

RESUMO

Sepsis is a life-threatening organ dysfunction condition caused by a dysregulated host response to an infection. Here we report that the circulating levels of growth and differentiation factor-15 (GDF15) are strongly increased in septic shock patients and correlate with mortality. In mice, we find that peptidoglycan is a potent ligand that signals through the TLR2-Myd88 axis for the secretion of GDF15, and that Gdf15-deficient mice are protected against abdominal sepsis due to increased chemokine CXC ligand 5 (CXCL5)-mediated recruitment of neutrophils into the peritoneum, leading to better local bacterial control. Our results identify GDF15 as a potential target to improve sepsis treatment. Its inhibition should increase neutrophil recruitment to the site of infection and consequently lead to better pathogen control and clearance.


Assuntos
Bacteriemia/imunologia , Quimiocina CXCL5/imunologia , Fator 15 de Diferenciação de Crescimento/imunologia , Neutrófilos/imunologia , Animais , Bacteriemia/genética , Bacteriemia/microbiologia , Bacteriemia/prevenção & controle , Quimiocina CXCL5/genética , Feminino , Fator 15 de Diferenciação de Crescimento/genética , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infiltração de Neutrófilos , Cavidade Peritoneal/microbiologia
8.
Gerontology ; 68(3): 261-271, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34515129

RESUMO

INTRODUCTION: Computed tomography (CT) of the chest, although not a screening test or diagnosis of infection with the new coronavirus, has a fundamental role in assessing the extent of lung involvement and complications such as pleural effusion. Considering the higher morbidity and mortality of elderly patients due to this infection, the objective of this study was to evaluate the imaging aspects and clinical correlations of an extreme age (≥80 years) with a confirmed diagnosis for COVID-19. METHODS: This was a retrospective and single-center cohort study. CT scans were categorized qualitatively and quantitatively. In the first case, 3 descriptors were used to describe CT findings: "compatible" (findings of greater specificity for COVID-19: opacities with attenuation in ground glass with peripheral and bilateral distribution, with rounded morphology, with or without consolidations, crazy-pavement aspect, inverted halo sign, or organizing pneumonia findings), "doubtful" (findings not specific or unusual for COVID-19: opacities with attenuation in ground glass with nonrounded morphology, central, diffuse, or unilateral distribution, with or without consolidation, lobar or segmental consolidation without ground-glass opacity, small centrilobular nodules with the appearance of "tree-in-bud," excavations, pleural effusion, and thickening of interlobular septa), and "negative" (absence of pneumonia signs). For the quantitative assessment, which referred to the extent of pulmonary involvement, a tomographic severity classification was used: grade 1 (lung involvement ≤25%), grade 2 (pulmonary involvement between 26 and 50%), and grade 3 (pulmonary involvement >50%). RESULTS: A total of 138 patients were evaluated, with an average age of 86.2 years (84 women and 34 men). The mean time interval between onset of symptoms and tomography was 5.63 days. The most prevalent comorbidity was systemic arterial hypertension (81.2%). Compatible, doubtful, and negative tests were 117 (84.7%), 20 (14.4%), and 1 (0.7%), respectively. As for compatible exams, the most common findings were opacities in peripheral ground glass and rounded morphology, followed by crazy paving. The prevalence of pleural effusion was 28.2% and consolidation was 63.7%, and none of these findings were influenced by the duration of symptoms (p = 0.08 and p = 0.2, respectively). The exams classified as grade 1, grade 2, and grade 3 were 57 (41.6%), 46 (33.6%), and 34 (24.8%), respectively. There were statistically significant associations between the classification of tomographic severity and outcomes such as invasive ventilation (p = 0.004), admission to the intensive care unit (p < 0.001), and death (p < 0.001). DISCUSSION/CONCLUSION: Our results show that patients ≥80 years old present tomographic manifestations similar to those described for the general population (ground-glass opacities and "crazy paving") and that the extent of lung involvement is associated with the need for intensive care, invasive ventilation, and death. Although the literature describes an association between the stage of the disease and the appearance of consolidations and pleural effusion, this correlation was not observed in our study, which may suggest that this age-group is more predisposed to the appearance of such findings, typically described in the more advanced stages of infection.


Assuntos
COVID-19 , Idoso , Idoso de 80 Anos ou mais , COVID-19/diagnóstico por imagem , Estudos de Coortes , Feminino , Humanos , Pulmão/diagnóstico por imagem , Masculino , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos
9.
Vet Pathol ; 58(3): 483-490, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33576305

RESUMO

Canine cutaneous mast cell tumors (ccMCTs) are currently graded according to Patnaik and Kiupel grading schemes. The qualitative and semiquantitative parameters applied in these schemes may lead to inter- and intraobserver variability. This study investigates the prognostic value of volume-weighted mean nuclear volume (vv¯), a stereological estimation that provides information about nuclear size and its variability. vv¯ of 55 ccMCTs was estimated using the "point-sampled intercept" method and compared with histological grade and clinical outcome. The clinical history of dogs treated with surgical excision alone was available for 30 ccMCTs. Statistical differences in vv¯ were found between grade II (x¯ = 115 ± 29 µm3) and grade III ccMCTs (x ¯= 197 ± 63 µm3), as well as between low-grade (x ¯= 113 ± 28 µm3) and high-grade ccMCTs (x¯ = 184 ± 63 µm3). An optimal cutoff value of vv¯ ≥ 150 µm3 and vv¯ ≥ 140 µm3 was determined for grade III and high-grade ccMCTs, respectively. In terms of prognosis, vv¯  was not able to predict the clinical outcome in 42% of the cases; however, cases with vv¯ <125 µm3 had a favorable outcome. These results indicate that, despite having limited prognostic value when used as a solitary parameter, vv¯ is highly reproducible and is associated with histological grade as well as with benign behavior.


Assuntos
Doenças do Cão , Neoplasias , Neoplasias Cutâneas , Animais , Núcleo Celular , Doenças do Cão/diagnóstico , Cães , Mastócitos , Neoplasias/veterinária , Variações Dependentes do Observador , Prognóstico , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/veterinária
10.
Mediators Inflamm ; 2021: 4194859, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34707461

RESUMO

BACKGROUND: IgE mediates type I hypersensitivity reaction and can be found in the mucosa of organs affected by allergy. Acute appendicitis (AA) is a common disease, but its etiology remains poorly understood. Here, we investigated IgE deposition in histological sections of AA samples to test the hypothesis that an allergic reaction may substantially contribute to the pathophysiology of AA. MATERIALS AND METHODS: In a retrospective study, we assessed the presence of IgE in appendicular specimens of histologically confirmed appendicitis and in the control group, comprised of negative appendicitis and incidental appendectomies, using a monoclonal antibody against human IgE. Samples from 134 appendectomies were included: 38 phlegmonous and 27 gangrenous appendicitis from the study group and 52 incidental appendectomies and 17 negative appendicitis from the control group. The slides were visualized by light microscopy, and a standard procedure was used to manually count the positive IgE staining cells. RESULTS: IgE staining was present in the cells of all but 5 appendicular specimens. We found a significantly increased number of IgE-positive cells in phlegmonous AA (median = 28) when compared to incidental appendectomy (median = 17) (p = 0.005; p < 0.0001 when adjusted for age and gender). No difference was found for gangrenous appendicitis. Discussion. The presence of IgE supports the contribution of an allergic reaction for the pathophysiology of phlegmonous appendicitis. The reduced number of IgE staining cells in gangrenous appendicitis can be due to tissue destruction, or, as been claimed by others, gangrenous appendicitis is a distinct entity, with different etiology. CONCLUSION: In this study, phlegmonous appendicitis had the highest number of IgE-positive appendicular cells. These findings suggest that an allergic reaction can contribute to the pathophysiology of AA, opening a novel possibility for preventive measures in a disease that typically requires surgery.


Assuntos
Apendicite/imunologia , Apêndice/imunologia , Hipersensibilidade Imediata/imunologia , Imunoglobulina E/análise , Doença Aguda , Adulto , Idoso , Apendicite/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
11.
J Vasc Bras ; 19: e20190070, 2020 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-34178056

RESUMO

The Society for Vascular Surgery has proposed a new classification system for the threatened lower limb, based on the three main factors that have an impact on limb amputation risk: Wound (W), Ischemia (I) and foot Infection ("fI") - the WIfI classification. The system also covers diabetic patients, previously excluded from the concept of critical limb ischemia because of their complex clinical condition. The classification's purpose is to provide accurate and early risk stratification for patients with threatened lower limbs; assisting with clinical management, enabling comparison of alternative therapies; and predicting risk of amputation at 1 year and the need for limb revascularization. The objective of this study is to collect together the main points about the WIfI classification that have been discussed in the scientific literature. Most of the studies conducted for validation of this classification system prove its association with factors related to limb salvage, such as amputation rates, amputation-free survival, prediction of reintervention, amputation, and stenosis (RAS) events, and wound healing.

12.
Mol Pharm ; 16(8): 3477-3488, 2019 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-31257891

RESUMO

Paclitaxel (PTX) is a microtubule-stabilizing agent widely used to treat breast cancer. Nevertheless, the low solubility of the drug and the side effects of commercial formulations available limit its clinical use. In this way, our group recently described the preparation of PTX-loaded folate-coated long-circulating and pH-sensitive liposomes (SpHL-folate-PTX). Therefore, a proof-of-concept study was designed in order to demonstrate the feasibility of SpHL-folate-PTX against breast tumor cell line MDA-MB-231. Cellular uptake of the liposomes and PTX was evaluated. Apoptosis and cell cycle were analyzed by flow cytometry. In vivo antitumor activity was carried out in MDA-MB-231 tumor-bearing BALB/c nude mice. Cellular uptake assay showed a high cell delivery of PTX by SpHL-folate-PTX, which leads to superior cytotoxicity and activation of apoptosis pathways. The SpHL-folate-PTX treatment induces an expressive increase of cells in the G0/G1 phase compared to free PTX and SpHL-PTX (without folate). In vivo studies showed a significant reduction in the tumor growth and a lower uptake of a radiopharmaceutical in the scintigraphic images for the SpHL-folate-PTX group, suggesting its higher efficacy compared with free PTX and SpHL-PTX. Histomorphometric analyses demonstrated an increase in necrosis and inflammation areas in animals treated with SpHL-folate-PTX. A decrease in the proliferative cells and a higher percentage of apoptotic cells were observed by immunohistochemical analyses after the treatment with SpHL-folate-PTX. Therefore, the data confirmed the potential of SpHL-folate-PTX as an alternative antitumor therapy, especially for breast cancer.


Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Composição de Medicamentos/métodos , Ácido Fólico/química , Paclitaxel/administração & dosagem , Animais , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacocinética , Apoptose/efeitos dos fármacos , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Feminino , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Lipossomos , Camundongos , Paclitaxel/química , Paclitaxel/farmacocinética , Estudo de Prova de Conceito , Cintilografia , Solubilidade , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Mediators Inflamm ; 2019: 8146257, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31772507

RESUMO

Acute appendicitis is the most frequent surgical abdominal emergency, but its etiology remains poorly understood. Histological examination of the appendix, following its removal due to acute appendicitis, consistently shows features in common with bronchial asthma, suggesting an allergic reaction as a candidate etiologic factor. Here, we propose the concept of appendicular lavage and use it to study the levels of the Th2 cytokines IL-4, IL-5, and IL-9 in patients with a clinical diagnosis of acute appendicitis. The study group included 20 patients with a histological diagnosis of phlegmonous appendicitis, 13 patients with gangrenous appendicitis, and a control group of 8 patients with a clinical diagnosis of appendicitis but with normal histology. Cytokine levels were higher in acute appendicitis. The difference was more pronounced when comparing phlegmonous appendicitis with nonpathological appendicitis (p = 0.01) for IL-4 (48.3 vs. 21.3 pg/mL), IL-5 (29.2 vs. 8.0 pg/mL), and IL-9 (34.1 vs. 16.6 pg/mL). This Th2 cytokine profile is compatible with the hypothesis of allergy as an etiologic factor for acute appendicitis and may have important implications for the diagnosis, prevention, and treatment of this condition.


Assuntos
Apendicite/etiologia , Apendicite/metabolismo , Citocinas/metabolismo , Hipersensibilidade/complicações , Hipersensibilidade/metabolismo , Células Th2/metabolismo , Doença Aguda , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
14.
Toxicol Appl Pharmacol ; 352: 162-169, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29864484

RESUMO

Doxorubicin (DOX) is widely used in cancer treatment, however, the use of this drug is often limited due to its cardiotoxic side effects. In order to avoid these adverse effects, the encapsulation of DOX into nanosystems has been used in the last decades. In this context, pH-sensitive liposomes have been shown promising for delivering cytotoxic agents into tumor cells, however, the lack of information about in vivo toxicity of this nanocarrier has impaired translational studies. Therefore, the aim of this work was to investigate the acute toxicity and cardiotoxicity of DOX-loading pH-sensitive liposomes (SpHL-DOX). To achieve this, female BALB/c mice, after intravenous administration, were monitored by means of clinical, laboratory, histopathological and electrocardiographic (ECG) analyses. Results indicate that SpHL was able to prevent renal toxicity and the hepatic injury was less extensive than free DOX. In addition, lower body weight loss was associated with less ECG QT interval prolongation to animals receiving SpHL-DOX (14.6 ±â€¯5.2%) compared to animals receiving free DOX (35.7 ±â€¯4.0%) or non-pH-sensitive liposomes (nSpHL-DOX) (47.0 ±â€¯9.8%). These results corroborate with SpHL-DOX biodistribution studies published by our group. In conclusion, the SpHL-DOX showed less toxic effects on mice compared to free DOX or nSpHL-DOX indicating that SpHL-DOX is a promising strategy to reduce the serious cardiotoxic effects of DOX.


Assuntos
Antibióticos Antineoplásicos/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Doxorrubicina/toxicidade , Avaliação Pré-Clínica de Medicamentos , Cardiopatias/prevenção & controle , Nefropatias/prevenção & controle , Animais , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/química , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Preparações de Ação Retardada , Doxorrubicina/administração & dosagem , Doxorrubicina/química , Composição de Medicamentos , Feminino , Coração/efeitos dos fármacos , Cardiopatias/induzido quimicamente , Cardiopatias/patologia , Concentração de Íons de Hidrogênio , Injeções Intravenosas , Rim/efeitos dos fármacos , Rim/patologia , Nefropatias/induzido quimicamente , Nefropatias/patologia , Lipossomos , Fígado/efeitos dos fármacos , Fígado/patologia , Camundongos Endogâmicos BALB C , Miocárdio/patologia
15.
Langmuir ; 34(20): 5728-5737, 2018 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-29676924

RESUMO

A long-circulating and pH-sensitive liposome containing paclitaxel (SpHL-PTX) was recently developed by our group. Once in an acidic environment, for example, tumors, these liposomes undergo destabilization, releasing the encapsulated drug. In this way, the aim of this study was to evaluate the molecular and supramolecular interactions between the lipid bilayer and PTX in similar biological environment conditions. High-sensitivity analyses of SpHL-PTX structures were obtained by the small-angle X-ray scattering technique combined with other techniques such as dynamic light scattering, asymmetric flow field-flow fractionation, transmission electron microscopy, and high-performance liquid chromatography. The results showed that PTX incorporation in the liposomal bilayer clearly leads to changes in supramolecular organization of dioleoylphosphatidylethanolamine (DOPE) molecules, inducing the formation of more ordered structures. Changes in supramolecular organization were observed at lower pH, indicating that pH sensitivity was preserved even in the presence of fetal bovine serum proteins. Furthermore, morphological and physicochemical characterization of SpHL-PTX evidenced the formation of nanosized dispersion suitable for intravenous administration. In conclusion, a stable nanosized dispersion of PTX was obtained at pH 7.4 with suitable parameters for intravenous administration. At lower pH conditions, the pH sensitivity of the system was clearly evidenced by changes in the supramolecular organization of DOPE molecules, which is crucial for the delivery of PTX into the cytoplasm of the targeted cells. In this way, the results obtained by different techniques confirm the feasibility of SpHL as a promising tool to PTX delivery in acidic environments, such as tumors.


Assuntos
Portadores de Fármacos/química , Lipossomos/química , Paclitaxel/química , Concentração de Íons de Hidrogênio
16.
Fish Shellfish Immunol ; 80: 651-654, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29859314

RESUMO

Recently, chitosan-based nanoparticles with mucoadhesive properties emerged as a strategy for mucosal drug release. This study aimed to characterize the interaction of mucoadhesive system chitosancoated PLGA nanoparticles (NPMA) with fish external mucus. NP suspensions with fluorescent probe were prepared and characterized by size, polydispersity, zeta potential and pH measures. In post-exposure fish were observed an increase in fluorescence imaging over time and it was significantly influenced by NPMA concentration. We also observed the main predominance the fluorescence in the spleen, followed by liver, gill and other tissues. The use of mucoadhesive nanocarriers becomes an alternative for administration of drugs and immunomodulators in immersion systems since the nanosystem can adhere to the mucosal surface of the fish with little residual effect in the water.


Assuntos
Quitosana/administração & dosagem , Portadores de Fármacos/administração & dosagem , Nanopartículas/administração & dosagem , Ácido Poliglicólico/administração & dosagem , Adesividade , Animais , Quitosana/química , Portadores de Fármacos/química , Corantes Fluorescentes/administração & dosagem , Brânquias/metabolismo , Imunomodulação , Fígado/metabolismo , Mucosa/química , Nanopartículas/química , Ácido Poliglicólico/química , Baço/metabolismo , Peixe-Zebra
17.
Sleep Breath ; 22(1): 211-221, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29247296

RESUMO

INTRODUCTION: Sleep related breathing disorders (SRBD) cause sleep fragmentation, intermittent hypoxia or a combination of both leading to homeostasis perturbations, including in the immune system. We investigated whether SRBD patients with or without intermittent hypoxia show substantial differences in perforin and granzyme-B positive peripheral blood lymphocytes. METHODS: A total of 87 subjects were included and distributed as follows: 24 controls (C), 19 patients with respiratory effort related arousals due to increased upper airway resistance (UAR) without hypoxic events, 24 obese patients with obstructive sleep apnea (OSA) (oOSA), and 20 without obesity (noOSA). After polysomnographic recording, we analyzed in fasting blood samples routine hematologic and biochemical parameters and the percentage of lymphocytes containing the proteins perforin and granzyme-B (GrB). Kruskal-Wallis tests and a posteriori multiple comparisons were applied for statistical analysis of results. RESULTS: Perforin-positive γδ-cells revealed significant differences between groups (p = 0.017), especially between the Control group and the oOSA (p-value = 0.04); the remaining SRBD groups also showed differences from the control (C vs UAR: p = 0.08; C vs noOSA = 0.09), but they did not raise to statistical significance. There were no differences among the SRBD groups. Granzyme-B cells were decreased in SRBD patients, but the differences were not statistically significant. No additional statistical significant result was found in the other investigated lymphocyte subsets. CONCLUSIONS: Obstructive sleep-disordered breathing is associated with a decrease in perforin-positive CD3+γδ-T cells. Although this finding was detected in lean patients without intermittent hypoxia, the reduction was only statistically significant in obese patients with severe OSA. Because CD3+γδ-T cells play an important role in the control of tumor cells, our findings are directly relevant for the study of the association of OSA and cancer.


Assuntos
Complexo CD3/metabolismo , Perforina/análise , Apneia Obstrutiva do Sono/sangue , Apneia Obstrutiva do Sono/imunologia , Linfócitos T/citologia , Linfócitos T/metabolismo , Adulto , Granzimas/análise , Granzimas/metabolismo , Humanos , Contagem de Linfócitos , Pessoa de Meia-Idade , Perforina/metabolismo , Polissonografia , Adulto Jovem
18.
Toxicol Appl Pharmacol ; 329: 272-281, 2017 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-28610991

RESUMO

Non-small cell lung cancer (NSCLC) is one of the most common malignant tumors, with a high mortality rate due to the elevated risk of resistance. Natural cucurbitacins and their derivatives are recognized as promising antitumor compounds for several types of cancer, including NSCLC. In a recent study published by our research group, DACE (2-deoxy-2-amine-cucurbitacin E), which is a semisynthetic derivative of cucurbitacin B, showed potential in vitro synergistic antiproliferative effects combined with paclitaxel (PTX) in A549 cells. In sequence, the purpose of this study was to evaluate the in vivo antitumor efficacy of this combined therapy as well as with these drugs individually, using a human NSCLC xenograft model. Some indicators of sub chronic toxicity that could be affected by treatments were also assessed. The results obtained in vivo with the combined treatment (1mg/kg+PTX 10mg/kg) showed the most effective reduction of the relative tumor volume and the highest inhibition of tumor growth and proliferation, when compared with those of the single treatments. Furthermore, scintigraphic images, obtained before and after the treatments, showed that the most effective protocol able to reduce the residual viable tumor mass was the combined treatment. All treatment regimens were well tolerated without significant changes in body weight and no histological and functional damage to liver and kidney tissues. These results corroborate our previous in vitro synergistic effects published. Taken together, these insights are novel and highlight the therapeutic potential of DACE and PTX combination scheme for NSCLC.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Paclitaxel/farmacologia , Triterpenos/farmacologia , Células A549 , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/toxicidade , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Antígeno Ki-67/metabolismo , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos Endogâmicos BALB C , Camundongos Nus , Paclitaxel/toxicidade , Compostos Radiofarmacêuticos/administração & dosagem , Fatores de Tempo , Testes de Toxicidade Subcrônica , Triterpenos/toxicidade , Carga Tumoral/efeitos dos fármacos , Imagem Corporal Total , Ensaios Antitumorais Modelo de Xenoenxerto
19.
Adv Exp Med Biol ; 987: 1-12, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28971442

RESUMO

Hyperthermia, the procedure of raising the temperature of a part of or the whole body above normal for a defined period of time, is applied alone or as an adjunctive with various established cancer treatment modalities such as radiotherapy and chemotherapy. In this study used a method for inducing hyperthermia in solid tumors with a combination of gold macro rod (GR) and ultrasound, the feasibility of this technique was described only with computational models and in vitro. The Ehrlich tumor, derived from a mouse adenocarcinoma, has been used to investigate the bio-heat transfer and the effect of gold rods irradiated with ultrasound. The in vivo measurements demonstrated that the technique inhibited more 80% of the tumor growth in both experimental models tested. These results not only confirm the bio heat transfer to tissue as predicted by analytical calculation and in vitro measurements, but are also proved to be a potential alternative to kill cancer cells.


Assuntos
Hipertermia Induzida/métodos , Neoplasias Experimentais/terapia , Terapia por Ultrassom/métodos , Animais , Linhagem Celular Tumoral , Terapia Combinada , Modelos Animais de Doenças , Humanos , Masculino , Camundongos Endogâmicos BALB C , Reprodutibilidade dos Testes , Fatores de Tempo , Resultado do Tratamento , Carga Tumoral
20.
Adv Exp Med Biol ; 987: 119-138, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28971453

RESUMO

PURPOSE: The aim of this study was to analyze feasibility (in vitro and in vivo) the use of hyperthermia produced by gold rods irradiated with ultrasound and their combination with chemotherapy with doxorubicin. MATERIALS AND METHODS: initially was determined the cell viability and Hsp70 levels after treatment by gold rods irradiated with ultrasound (GR+U) in cell culture. The pretreatment with GR+U combined with doxorubicin (DOX) was evaluated from IC50, caspase-3 expression and mechanisms of cell death by electron microscopy. For evaluate the in vivo effects was used solid Ehrlich carcinoma (SEC) Tumor. The animals received three treatments with the combination of GR+U+DOX over 16 days. RESULTS: The cell viability was completely inhibited after 40 min of treatment with GR+U and significant increases the expression of HSP70 was only observed after 10 min of treatment. GR+U+DOX presented significant reduction of IC50 representing 50.7%, 76.5% 45.2% and 46.6% for cell lines K562, NCI-H292, Hep-2 and MCF-7 respectively. GR+U+DOX presented significant reduction of IC50 representing 50.7%, 76.5% 45.2% and 46.6% for cell lines K562, NCI-H292, Hep-2 and MCF-7 respectively. The caspase-3 level and ultraestructural analysis showed that treatment with GR+U+DOX enhances induction of apoptosis. Pretreatment with GR+U combined with doxorubicin (1 mg) showed 87% inhibition against SEC. and no showed cardiotoxic effect. CONCLUSIONS: The combined treatment of GR+U and DOX exhibit synergistic characteristics observed by increasing the efficiency of doxorubicin.


Assuntos
Doxorrubicina/farmacologia , Hipertermia Induzida/métodos , Neoplasias Experimentais/terapia , Terapia por Ultrassom/métodos , Animais , Antibióticos Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Terapia Combinada , Ouro , Proteínas de Choque Térmico HSP70/metabolismo , História Antiga , Temperatura Alta , Humanos , Células K562 , Células MCF-7 , Masculino , Camundongos Endogâmicos BALB C , Microscopia Eletrônica de Transmissão , Ondas Ultrassônicas
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa