Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
1.
J Hematol Oncol ; 17(1): 4, 2024 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-38191498

RESUMO

Myelodysplastic neoplasms (MDS) define clonal hematopoietic malignancies characterized by heterogeneous mutational and clinical spectra typically seen in the elderly. Curative treatment entails allogeneic hematopoietic stem cell transplant, which is often not a feasible option due to older age and significant comorbidities. Immunotherapy has the cytotoxic capacity to elicit tumor-specific killing with long-term immunological memory. While a number of platforms have emerged, therapeutic vaccination presents as an appealing strategy for MDS given its promising safety profile and amenability for commercialization. Several preclinical and clinical trials have investigated the efficacy of vaccines in MDS; these include peptide vaccines targeting tumor antigens, whole cell-based vaccines and dendritic cell-based vaccines. These therapeutic vaccines have shown acceptable safety profiles, but consistent clinical responses remain elusive despite robust immunological reactions. Combining vaccines with immunotherapeutic agents holds promise and requires further investigation. Herein, we highlight therapeutic vaccine trials while reviewing challenges and future directions of successful vaccination strategies in MDS.


Assuntos
Neoplasias Hematológicas , Síndromes Mielodisplásicas , Vacinas , Idoso , Humanos , Síndromes Mielodisplásicas/terapia , Imunoterapia , Vacinação
2.
ACS Appl Mater Interfaces ; 15(23): 27515-27532, 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37264797

RESUMO

Magnetic nanoparticle (MNP)-mediated magnetic hyperthermia (MHT) under an alternating magnetic field (AMF) causes tumor regression via reactive oxygen species (ROS) generation. However, less therapeutic efficacy has been reported due to the generation of low levels of ROS in a hypoxic tumor microenvironment. Therefore, improved treatments are required to generate relatively high levels of ROS to promote irreversible oxidative damage to the tumor cells. Herein, we report a magnetothermodynamic (MTD) therapy, as a robust and versatile approach for cancer treatment, by combining the magnetothermodynamic-related ROS and heat-related immunological effect in order to overcome the aforementioned obstacle. The synergistic therapy was achieved by the development of vitamin k3 (Vk3)-loaded copper zinc ferrite nanoparticles (Vk3@Si@CuZnIONPs) as an efficient MTD agent. The in vitro results unveiled that enhanced ROS production under the influence of AMF is a predominant aspect in yielding an assertive anticancer response. The in vivo antitumor response was assessed in an ectopic tumor model of A549 lung adenocarcinoma by MTD. The tumor inhibition rate of 69% was achieved within 20 days of MTD treatment, exhibiting complete tumor eradication within 30 days. The validation of antitumor response was marked by severe apoptosis (TUNEL, Caspase-3) in the Vk3@Si@CuZnIONPs + AMF-treated group. The higher expression level of heat shock proteins and proinflammatory cytokines (IL-6, TNF-α, IL-1α, IL-1ß) was speculated to play a role in the activation of immune response for faster tumor regression in the MTD-treated group. Therefore, by implementing a dual ROS and heat-mediated immunogenic effect, the antitumor efficiency of future cancer magnetotherapies will be greatly enhanced.


Assuntos
Hipertermia Induzida , Nanopartículas de Magnetita , Espécies Reativas de Oxigênio/metabolismo , Vitamina K 3/farmacologia , Linhagem Celular Tumoral , Hipertermia Induzida/métodos , Campos Magnéticos , Imunidade
3.
Biomater Adv ; 139: 213021, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35882116

RESUMO

Development of multifunctional magnetic nanomaterials (MNPs) with improved heat-generating capabilities and effective combination with localized chemotherapy has emerged as a promising therapeutic regime for solid tumors like glioblastoma. In this regard, the shape-dependent hyperthermic and chemo-therapeutic potential of nanomaterials, has not been extensively explored. Here we present, development of various morphological designs of MNPs including spherical, clusters, rods and cubic; to compare the effect of shape on tuning the properties of MNPs that are relevant to many potential biomedical applications like drug delivery, cellular uptake and heat generation. The study includes extensive comparison of morpho-structural characteristics, size distributions, chemical composition, surface area measurements and magnetic properties of the variable shaped MNPs. Further the heating efficiencies in aqueous and cellular environments and heat triggered drug release profiles for successful magneto-chemotherapy were compared among all in-house synthesized MNPs. Under biosafety limit considerations given by Hergt's limit (H*f value <5 × 109 Am-1 s-1), cuboidal shaped MNPs demonstrated highest heating efficiency owing to magnetosome-like chain formation along with sustained drug release profile as compared to other synthesized MNPs. The mechanism of cancer cell death mediated via magneto-chemotherapy was elucidated to be the oxidative stress-mediated apoptotic cell death pathway. In vivo studies further demonstrated complete tumor regression only in the magneto-chemotherapy treated group. These findings suggest the potential of combinatorial therapy to overcome the clinical limitations of the independent therapies for advanced thermotherapy of glioblastoma.


Assuntos
Glioblastoma , Hipertermia Induzida , Nanopartículas de Magnetita , Sistemas de Liberação de Medicamentos , Glioblastoma/tratamento farmacológico , Calefação , Humanos
4.
Stroke ; 53(5): 1802-1812, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35354299

RESUMO

Cerebral ischemia and reperfusion initiate cellular events in brain that lead to neurological disability. Investigating these cellular events provides ample targets for developing new treatments. Despite considerable work, no such therapy has translated into successful stroke treatment. Among other issues-such as incomplete mechanistic knowledge and faulty clinical trial design-a key contributor to prior translational failures may be insufficient scientific rigor during preclinical assessment: nonblinded outcome assessment; missing randomization; inappropriate sample sizes; and preclinical assessments in young male animals that ignore relevant biological variables, such as age, sex, and relevant comorbid diseases. Promising results are rarely replicated in multiple laboratories. We sought to address some of these issues with rigorous assessment of candidate treatments across 6 independent research laboratories. The Stroke Preclinical Assessment Network (SPAN) implements state-of-the-art experimental design to test the hypothesis that rigorous preclinical assessment can successfully reduce or eliminate common sources of bias in choosing treatments for evaluation in clinical studies. SPAN is a randomized, placebo-controlled, blinded, multilaboratory trial using a multi-arm multi-stage protocol to select one or more putative stroke treatments with an implied high likelihood of success in human clinical stroke trials. The first stage of SPAN implemented procedural standardization and experimental rigor. All participating research laboratories performed middle cerebral artery occlusion surgery adhering to a common protocol and rapidly enrolled 913 mice in the first of 4 planned stages with excellent protocol adherence, remarkable data completion and low rates of subject loss. SPAN stage 1 successfully implemented treatment masking, randomization, prerandomization inclusion/exclusion criteria, and blinded assessment to exclude bias. Our data suggest that a large, multilaboratory, preclinical assessment effort to reduce known sources of bias is feasible and practical. Subsequent SPAN stages will evaluate candidate treatments for potential success in future stroke clinical trials using aged animals and animals with comorbid conditions.


Assuntos
Isquemia Encefálica , Acidente Vascular Cerebral , Idoso , Animais , Encéfalo , Isquemia Encefálica/terapia , Estudos de Viabilidade , Humanos , Infarto da Artéria Cerebral Média/terapia , Masculino , Camundongos , Acidente Vascular Cerebral/terapia
5.
3 Biotech ; 11(6): 254, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33987071

RESUMO

During our previous investigation, bioactive compounds present in the extract of Streptomyces sp. strain 196 were characterized using LC-MS/MS and 1H NMR studies. These compounds were K-252-C aglycone indolocarbazole alkaloid, decoyinine, and cycloheximide; the study of these natural drugs against lung carcinoma is still limited. Focus of the current investigation was to study the anticancer effect of strain 196 extract on lung cancer cells (A549). During in vitro studies, anti-proliferative effect of extract was studied using MTT assay in A549 cells. Effect of extract on cell survival was further evaluated using colony assay. Cell death was qualitatively assessed using apoptosis assay. The aftereffect of extract treatment on metastatic potential of cancerous cells was studied using wound closure assay. Effect of extract on the morphology and cytoskeletal arrangement of A549 cells was studied using phalloidin staining. The extract demonstrated concentration and time-dependent cytotoxicity with IC50 value at 0.5 mg/ml (6 h) and 0.15 mg/ml (24 h). The proliferation and metastatic potential of cells, as characterized by MTT and migration assay, decreased over time in a concentration-dependent manner. Discrete changes in cellular morphology were noted as a result of the induced cytotoxicity. Apoptosis assay demonstrated 98.7% cell death at highest concentration of extract (1 mg/ml). During in silico studies, molecular docking revealed that strain 196 compounds are efficiently binding to mutant EGFR form (T790M/L858R) with release of binding energy (∆G) between - 5 and - 6.9 kcal/Mol. In conclusion, strain 196 extract could be a source of therapeutic drugs to treat lung carcinoma.

6.
Stroke ; 52(7): 2381-2392, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33940958

RESUMO

Background and Purpose: Stroke induces the expression of several long noncoding RNAs in the brain. However, their functional significance in poststroke outcome is poorly understood. We recently observed that a brain-specific long noncoding RNA called Fos downstream transcript (FosDT) is induced rapidly in the rodent brain following focal ischemia. Using FosDT knockout rats, we presently evaluated the role of FosDT in poststroke brain damage. Methods: FosDT knockout rats were generated using CRISPR-Cas9 genome editing on a Sprague-Dawley background. Male and female FosDT−/− and FosDT+/+ cohorts were subjected to transient middle cerebral artery occlusion. Postischemic sensorimotor deficits were evaluated between days 1 and 7 and lesion volume on day 7 of reperfusion. The developmental expression profile of FosDT was determined with real-time polymerase chain reaction and mechanistic implications of FosDT in the ischemic brain were conducted with RNA-sequencing analysis and immunostaining of pathological markers. Results: FosDT expression is developmentally regulated, with the adult cerebral cortex showing significantly higher FosDT expression than neonates. FosDT−/− rats did not show any anomalies in growth and development, fertility, brain cytoarchitecture, and cerebral vasculature. However, when subjected to transient focal ischemia, FosDT−/− rats of both sexes showed enhanced sensorimotor recovery and reduced brain damage. RNA-sequencing analysis showed that improved poststroke functional outcome in FosDT−/− rats is partially associated with curtailed induction of inflammatory genes, reduced apoptosis, mitochondrial dysfunction, and oxidative stress. Conclusions: Our study shows that FosDT is developmentally dispensable, mechanistically important, and a functionally promising target to reduce ischemic brain damage and facilitate neurological recovery.


Assuntos
Encéfalo/crescimento & desenvolvimento , Proteínas Proto-Oncogênicas c-fos/genética , RNA Longo não Codificante/genética , Recuperação de Função Fisiológica/fisiologia , Acidente Vascular Cerebral/genética , Animais , Encéfalo/metabolismo , Feminino , Masculino , Proteínas Proto-Oncogênicas c-fos/deficiência , RNA Longo não Codificante/biossíntese , Ratos , Ratos Sprague-Dawley , Ratos Transgênicos , Acidente Vascular Cerebral/fisiopatologia
7.
Biomater Sci ; 9(8): 2972-2990, 2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33635305

RESUMO

Among conventional cancer therapies, radio-frequency magnetic hyperthermia (MHT) has widely been investigated for use with magnetic nanoparticles (MNPs). However, the majority of in vivo biodistribution studies have tested very low MNP dosages (equivalent to magnetic resonance imaging (MRI) applications) to check for clearance rate; which is far below the clinical dose of MHT. Due to this poor validation in preclinical scenarios, quite a few MNPs already in clinical use were later discontinued, on grounds of unexpected clinical outcomes in terms of inflammation, and prolonged clearance in vivo. By exploiting an economical method of synthesis, we have developed chitosan-coated Fe3O4 nanoparticles with high heating efficiency performance. Their anti-tumor response was evaluated in an ectopic tumor model of C6 glioblastoma by MHT. The intratumoral injection of MNPs on days 1 and 7 resulted in rapid tumor inhibition rate of 69.4% within 8 days, with complete inhibition within 32 days, and no recurrence recorded over a 5-month follow-up. Notably, the MNP-mediated MHT therapy achieved the highest degree of therapeutic efficacy required for complete tumor ablation by combining controlled temperature range (<44 °C), reduced MNP dosage; much lower than in most reported studies, and AMF parameters (time of exposure and frequency) within the clinical safety limit. Periodic body weight measurements confirmed negligible adverse side effects in rats. The anti-tumor activity was validated by severe apoptosis (TUNEL, cleaved Caspase-3), reduced proliferation (Ki 67) and disrupted vasculature (CD 31) in the Fe3O4-MHT-treated group. Real-time gene expression of pro-inflammatory cytokines (IL-6, TNF-α, IL-1α, IL-1ß) confirmed the intratumoral activation of IL-6, suggesting the role of immunomodulation in triggering the adaptive immune response for faster tumor regression in the treated group. In addition, the biodistribution and clearance rate of MNPs monitored using ICP-OES confirmed their time-dependent biodegradation via excretion (urine, feces), phagocytosis (liver) and circulatory system (blood), with negligible deposition in other major organs (kidney, heart, lungs). Although we could not show complete clearance of our MNPs within the time frame tested, future studies should focus on combining MHT with immunotherapy, and target tumors at a much-reduced iron dose, consequently improving in vivo clearance rate, and hence overcoming the limitations of MHT in clinical therapy.


Assuntos
Hipertermia Induzida , Nanopartículas de Magnetita , Animais , Caspase 3 , Linhagem Celular Tumoral , Compostos Férricos , Glioblastoma , Nanopartículas Magnéticas de Óxido de Ferro , Ratos , Distribuição Tecidual
8.
Food Chem ; 334: 127563, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32791433

RESUMO

A new magnetic Cu(II) IIP (Fe3O4@IIP-IDC) is synthesized by polymerization of Imidazole-4,5-dicarboxylic acid functionalized Allyl chloride, and significant improvement of its performance has been compared. SPE parameters were optimized using Box-Behnken design to achieve the twin objectives of quantitative determination and removal of Cu(II). FLPSO kinetic model and BS isotherm model fits well with the capacity of 175 mg g-1. Analytical figures of merit includes a linearity range of 10-5,000 µg L-1 (R2 = 0.9986), preconcentration factor of 50 after eluting with 5 mL of 1 M HNO3, LOD of 1.03 µg L-1 and LOQ of 4.5 µg L-1. Accuracy was assessed by analysis of SRM (Standard Reference Material) and recovery experiments after spiking in food samples (Tea, coffee, chocolate, spinach, infant milk substitute) and battery wastewater. Ease of use, reusability (15 cycles), rapid adsorption and high selectivity makes it a promising candidate for efficient and selective removal and trace determination.


Assuntos
Cobre/análise , Análise de Alimentos/métodos , Impressão Molecular/métodos , Polímeros/química , Poluentes Químicos da Água/análise , Adsorção , Compostos Alílicos/química , Cobre/isolamento & purificação , Ácidos Dicarboxílicos/química , Análise de Alimentos/instrumentação , Contaminação de Alimentos/análise , Imidazóis/química , Limite de Detecção , Fenômenos Magnéticos , Águas Residuárias/análise , Poluentes Químicos da Água/isolamento & purificação
9.
Exp Neurol ; 336: 113530, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33221396

RESUMO

Microglia are one of the first responders to ischemic injury. Aged microglia acquire a senescent phenotype and produce more inflammatory cytokines after stroke. Depletion of microglia in young mice worsens post-ischemic damage by increasing inflammation. However, young mice do not have dysfunctional microglia. Hence, we hypothesized that depletion of microglia in older mice will contribute to improved early recovery after ischemic stroke injury. Aged (18-19 month) mice were fed with either control chow diet (CD) or PLX5622 chow diet (PLXD) for 21 days. On day 22, a 60-min middle cerebral artery occlusion (MCAo) surgery or sham surgery was performed. Twenty-four and 72 h after stroke immunohistochemistry and flow cytometry were performed. AFS98, a monoclonal antibody against CSF1R was used to specifically deplete brain macrophages by injection into the right hemisphere. Two days after AFS98 injections, mice underwent one-hour MCAo. Twenty-four hours later mice were euthanized and flow cytometry was performed. An increase in infarct volume (p < 0.05) was seen in the PLXD versus CD after stroke in aged mice at 24 and 72 h. An increase (p < 0.05) in infiltrating monocytes was observed after microglial depletion in aged stroke mice suggesting a differential monocyte response. An increase in astrocyte numbers was evident in the PLXD sham mice compared to CD sham, reflecting the off-target effects of PLX5622 treatment. In conclusion, PLX5622 and AFS98 treatment depleted microglia in aged animals but resulted in increased neuroinflammation after ischemic stroke.


Assuntos
Encéfalo/patologia , AVC Isquêmico/patologia , Microglia/patologia , Acidente Vascular Cerebral/patologia , Envelhecimento , Animais , Astrócitos/patologia , Proteínas de Ligação ao Cálcio/deficiência , Proteínas de Ligação ao Cálcio/genética , Infarto da Artéria Cerebral Média/patologia , Inflamação/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas dos Microfilamentos/deficiência , Proteínas dos Microfilamentos/genética , Monócitos/patologia , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos/antagonistas & inibidores , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos/genética
10.
J Neuroinflammation ; 17(1): 160, 2020 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-32429999

RESUMO

BACKGROUND: Risk of stroke-related morbidity and mortality increases significantly with age. Aging is associated with chronic, low-grade inflammation, which is thought to contribute to the poorer outcomes after stroke seen in the elderly. Histamine (HA) is a major molecular mediator of inflammation, and mast cells residing in the gut are a primary source of histamine. METHODS: Stroke was induced in male C57BL/6 J mice at 3 months (young) and 20 months (aged) of age. Role of histamine after stroke was examined using young (Yg) and aged (Ag) mice; mice underwent MCAO surgery and were euthanized at 6 h, 24 h, and 7 days post-ischemia; sham mice received the same surgery but no MCAO. In this work, we evaluated whether worsened outcomes after experimental stroke in aged mice were associated with age-related changes in mast cells, histamine levels, and histamine receptor expression in the gut, brain, and plasma. RESULTS: We found increased numbers of mast cells in the gut and the brain with aging. Using the middle cerebral artery occlusion (MCAO) model of ischemic stroke, we demonstrate that stroke leads to increased numbers of gut mast cells and gut histamine receptor expression levels. These gut-centric changes are associated with elevated levels of HA and other pro-inflammatory cytokines including IL-6, G-CSF, TNF-α, and IFN-γ in the peripheral circulation. Our data also shows that post-stroke gut inflammation led to a significant reduction of mucin-producing goblet cells and a loss of gut barrier integrity. Lastly, gut inflammation after stroke is associated with changes in the composition of the gut microbiota as early as 24-h post-stroke. CONCLUSION: An important theme emerging from our results is that acute inflammatory events following ischemic insults in the brain persist longer in the aged mice when compared to younger animals. Taken together, our findings implicate mast cell activation and histamine signaling as a part of peripheral inflammatory response after ischemic stroke, which are profound in aged animals. Interfering with histamine signaling orally might provide translational value to improve stroke outcome.


Assuntos
Envelhecimento/patologia , Histamina/metabolismo , Inflamação/patologia , Intestinos/imunologia , Mastócitos/patologia , Acidente Vascular Cerebral/patologia , Envelhecimento/imunologia , Animais , Microbioma Gastrointestinal , Histamina/imunologia , Inflamação/imunologia , Intestinos/microbiologia , Masculino , Mastócitos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Acidente Vascular Cerebral/imunologia
11.
Brain Behav Immun ; 87: 556-567, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32058038

RESUMO

INTRODUCTION: Stroke is a disease that presents with well-known sex differences. While women account for more stroke deaths, recent data show that after adjusting for age and pre-stroke functional status, mortality is higher in men. Immune responses are key determinants of stroke outcome and may differ by sex. This study examined sex differences in central and peripheral T cell immune responses, systemic effects on gut permeability and microbiota diversity and behavioral outcomes after stroke in aged mice. We hypothesized that there are sex differences in the immune response to stroke in aged animals. METHODS: C57BL/6CR mice (20-22 months) were subjected to 60 min middle cerebral artery occlusion, or sham surgery. T cells were quantified in brain and blood at 3, 7 and 15 days (d) post-stroke by flow cytometry. Peripheral effects on gut permeability and microbiota diversity, as well as neurological function were assessed up to 14 d, and at 21 d (cognitive function) post-stroke. Brain glial fibrillary acidic protein (GFAP) expression was evaluated at 42 d post-stroke. RESULTS AND DISCUSSION: Mortality (50% vs 14%, p < 0.05) and hemorrhagic transformation (44% vs 0%) were significantly higher in males than in females. No difference in infarct size at 3d were observed. Peripherally, stroke induced greater gut permeability of FITC-dextran in males at d3 (p < 0.05), and non-reversible alterations in microbiota diversity in males. Following the sub-acute phase, both sexes demonstrated a time-dependent increase of CD4+ and CD8+ T cells in the brain, with significantly higher levels of CD8+ T cells and Regulatory T cells in males at d15 (p < 0.01). Aged males demonstrated greater neurological deficits up to d5 and impaired sensorimotor function up to d15 when assessed by the corner asymmetry test (p < 0.001 and p < 0.01, respectively). A trend in greater cognitive decline was observed at d21 in males. Increased GFAP expression in the ischemic hemisphere, indicating astroglial activation and gliosis, was demonstrated in both males and females 42d post-stroke. Our findings indicate that despite a similar initial ischemic brain injury, aged male mice experience greater peripheral effects on the gut and ongoing central neuroinflammation past the sub-acute phase after stroke.


Assuntos
Isquemia Encefálica , Microbioma Gastrointestinal , AVC Isquêmico , Acidente Vascular Cerebral , Animais , Linfócitos T CD8-Positivos , Feminino , Imunidade , Infarto da Artéria Cerebral Média , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Permeabilidade , Caracteres Sexuais
12.
Nanomedicine (Lond) ; 15(4): 355-379, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31992134

RESUMO

Aim: To explore the optimum temperature for cancer cell death using magnetic hyperthermia (MH), which in turn will affect the mode of cell death. Method: The focus of this study is to improve upon the existing methodology for the synthesis of chitosan encapsulated Fe3O4. MH was done at different temperatures. The cell death pathway was explored using flow cytometry and western blot. Results: Coated Fe3O4 exhibited low cytotoxicity, high stability and heating efficiency. MH at 43°C was the optimum temperature for robust cell death. Cell death pathway suggested that during the initial stages of recovery, apoptosis was the main mode of cell death. While at later stages, major apoptosis and minor necrosis were observed. Conclusion: It is important to find out the long-term effect of hyperthermia treatment on cancer cells and their consequences on surrounding healthy cells.


Assuntos
Caspase 3/metabolismo , Compostos Férricos/química , Hipertermia Induzida/métodos , Nanopartículas de Magnetita/química , Apoptose , Western Blotting , Citometria de Fluxo , Humanos , Temperatura
13.
Exp Neurol ; 326: 113202, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31954116

RESUMO

T-lymphocytes have a multifaceted role in ischemic stroke, but the majority of studies have been conducted in young mice, which may limit the translational value of these findings. Previous studies have shown that aging results in T cell dysfunction, leading to enhanced production of pro-inflammatory cytokines and chemokines, including interferon gamma (IFN-γ) and interferon-gamma-inducible protein (IP-10). This study assessed the role of T cells and pro-inflammatory factors on histologic and functional outcomes in an aged mouse model. Levels of IP-10 were measured in the brain and serum of young and aged male mice following middle cerebral artery occlusion (MCAo) or sham surgery. Additionally, IP-10 levels were evaluated in stroke patients. To directly determine the role of brain-infiltrating T cells after stroke, a separate cohort of aged male and female animals received either an anti-CD4 depletion antibody or IgG isotype control at 72 and 96 h following experimental stroke. Behavioral assessments were performed on day 7 post-MCAo. CD4 T cell depletion resulted in improved behavioral outcomes, despite the lack of differences in infarct size between the isotype control and anti-CD4 antibody treated stroke groups. Circulating IP-10 levels were increased in both humans and mice with age and stroke, and depletion of CD4 T cells led to a reduction in IFN-γ and IP-10 levels in mice. Since anti-CD4 treatment was administered three days after stroke onset, targeting this inflammatory pathway may be beneficial to aged stroke patients who present outside of the current time window for thrombolysis and thrombectomy.


Assuntos
Isquemia Encefálica/terapia , Linfócitos T CD4-Positivos , Acidente Vascular Cerebral/terapia , Envelhecimento , Animais , Comportamento Animal , Química Encefálica , Isquemia Encefálica/psicologia , Quimiocinas/biossíntese , Citocinas/biossíntese , Feminino , Infarto da Artéria Cerebral Média/metabolismo , Inflamação/metabolismo , Inflamação/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Acidente Vascular Cerebral/psicologia , Resultado do Tratamento
14.
Small GTPases ; 11(4): 293-300, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-29173011

RESUMO

Macrophages are innate immune cells that constantly patrol an organism to fulfill protective and homeostatic roles. Previous studies have shown that Rho GTPase activity is required for macrophage mobility, yet the roles of upstream regulatory proteins controlling Rho GTPase function in these cells are not well defined. Previously we have shown that the RhoA GEF Net1 is required for human breast cancer cell motility and extracellular matrix invasion. To assess the role of Net1 in macrophage motility, we isolated bone marrow macrophage (BMM) precursors from wild type and Net1 knockout mice. Loss of Net1 did not affect the ability of BMM precursors to differentiate into mature macrophages in vitro, as measured by CD68 and F4/80 staining. However, Net1 deletion significantly reduced RhoA activation, F-actin accumulation, adhesion, and motility in these cells. Nevertheless, similar to RhoA/RhoB double knockout macrophages, Net1 deletion did not impair macrophage recruitment to the peritoneum in a mouse model of sterile inflammation. These data demonstrate that Net1 is an important regulator of RhoA signaling and motility in mouse macrophages in vitro, but that its function may be dispensable for macrophage recruitment to inflammatory sites in vivo.


Assuntos
Actinas/metabolismo , Citoesqueleto/metabolismo , Macrófagos/metabolismo , Proteínas Oncogênicas/genética , Fatores de Troca de Nucleotídeo Guanina Rho/genética , Animais , Diferenciação Celular , Células Cultivadas , Deleção de Genes , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Oncogênicas/deficiência , Proteínas Oncogênicas/metabolismo , Fatores de Troca de Nucleotídeo Guanina Rho/metabolismo
15.
Sci Rep ; 8(1): 17560, 2018 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-30510289

RESUMO

Graphene oxide (GO) was immobilized innovatively through azo spacer arm onto the surface of polymeric Amberlite XAD-16 resin in order to expose all oxygen functionalities freely available for metal ions coordination and further modification with picolylamine which governs selectivity. The GO Amberlite XAD-16 picolylamine enables the development of SPE column coupled with ICP-OES for preconcentration and determination of Pb (II) and Cu (II) in water and fish samples. Elution was performed by mild acid (2M HCl) no other carcinogenic organic solvent was used, prevents ligand leaching. Under optimized conditions, the preconcentration factors of 150 and detection limits 1.434 and 0.048 µg L-1 for Pb (II) and Cu (II)  were obtained respectively.


Assuntos
Cobre/análise , Produtos Pesqueiros/análise , Análise de Alimentos/métodos , Grafite/química , Chumbo/análise , Polímeros/química , Extração em Fase Sólida/métodos , Análise Espectral/métodos
16.
Front Immunol ; 9: 659, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29670627

RESUMO

The prevalence of cardiovascular disease has increased among middle-aged women in the United States, yet has declined in middle-aged men. In experimental stroke, middle-aged females have larger strokes and greater inflammation than age-matched males or younger females. The mechanism underlying this shift from an "ischemia-protected" to an "ischemia-sensitive" phenotype in aging females is unknown. One potential factor is an age-related increase in systemic factors that induce inflammation. Increased abdominal fat deposition is seen in women during middle age. Adipose tissue plays a key role in obesity-induced systemic inflammation, including increased pro-inflammatory cytokines. We hypothesized that age and sex differences in adipose immune cells promote an augmented pro-inflammatory milieu in middle-aged females driven by a balance shift between pro-inflammatory and anti-inflammatory T cells. Abdominal adipose tissue immune cells from young (3-4 months) and middle-aged (15-16 months) male and female C57BL/6J mice were analyzed by flow cytometry. Plasma triglyceride (TG), high-density lipoprotein (HDL), and low-density lipoprotein (LDL) levels were determined with colorimetric assays. Middle-aged mice had higher adipose tissue mass compared to young mice. Lipid profiling showed no sex differences in TG and LDL, but middle-aged females had lower HDL (0.84 ± 0.07 µg/µl) than middle-aged males (1.35 ± 0.06 µg/µl). Flow cytometry data demonstrated an age-associated increase in adipose tissue CD8+ T cells that was augmented by female sex, with middle-aged females having a higher percentage of CD8+ cells (34.4 ± 3.2% of CD3+ T cells) than middle-aged males (24.4 ± 2.2%). This increase in CD8+ T-cell proportion was adipose tissue-specific, as this change was not observed in blood. Middle-aged females had higher numbers of activated (CD69+) CD8+ T cells than males. In addition, female CD8+ T cells produced higher levels of IFN-γ, TNF-α, and granzyme B ex vivo, and females had higher adipose levels of IFN-γ, RANTES and MIP-1ß than middle-aged males. In parallel, females had lower levels of regulatory T cells (Tregs), an anti-inflammatory T-cell subtype, compared to age-matched males. In conclusion, middle-aged females have a detrimental combination of elevated pro-inflammatory T cells and decreased anti-inflammatory Tregs in adipose tissue, which may promote a pro-inflammatory milieu and contribute to increased cardiovascular disease burden in aging females.


Assuntos
Gordura Abdominal/imunologia , Tecido Adiposo/imunologia , Envelhecimento/fisiologia , Linfócitos T CD8-Positivos/imunologia , Doenças Cardiovasculares/imunologia , Fatores Sexuais , Linfócitos T Reguladores/imunologia , Animais , Feminino , Granzimas/metabolismo , Humanos , Mediadores da Inflamação/metabolismo , Interferon gama/metabolismo , Lipoproteínas HDL/metabolismo , Ativação Linfocitária , Masculino , Camundongos , Fator de Necrose Tumoral alfa/metabolismo
17.
J Mater Chem B ; 6(33): 5385-5399, 2018 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-32254502

RESUMO

We have produced an innovative, theranostic hybrid nanocomposite of graphene oxide and iron oxide (GO-Fe3O4) for radio-frequency hyperthermia therapy. A new electrochemical synthesis route for the GO-Fe3O4 nanocomposite is employed. Superparamagnetic nanoparticles used for magnetic hyperthermia for biomedical application face longstanding obstacles, including the large number of nanoparticles required to achieve the desired therapeutic temperature, poor colloidal stability in aqueous suspension or physiological media, poor biocompatibility and, most importantly, low specific absorption rate (SAR). To limit the dosage of nanoparticles for therapeutic use, efforts are being made to increase the heating efficiency of nanoparticles. We have introduced an alternative way to increase the SAR value by improving the colloidal stability of magnetic nanoparticles. It is necessary to immobilize these nanoparticles on a support to prevent their agglomeration and precipitation in aqueous suspension. To address these issues, we report a reproducible electrochemical synthesis route for the GO-Fe3O4 nanocomposite. Our nanocomposite demonstrated good colloidal stability and low cytotoxicity in vitro. Due to its good colloidal stability, the nanocomposite had a high SAR of 543 W g-1 and corresponding intrinsic loss power of 5.98 nH m2 kg-1, which is 46% better than the best commercial equivalents. In vitro cytotoxicity studies demonstrated almost 70% cell viability at 200 µg mL-1 GO-Fe3O4 nanocomposite, a comparable concentration for clinical use according to FDA standards. We also showed the therapeutic potential of the nanocomposite using magnetic hyperthermia. We observed cancer cell (A549 human lung epithelial adenocarcinoma) ablation at 41, 42 and 43 °C for 30, 45, and 60 min. A maximum cancer cell death rate of 80.5% was observed at 43 °C for 60 min under alternating magnetic field exposure. Thus, the nanocomposites could be used in the efficient treatment of cancer.

18.
Braz. j. microbiol ; 48(2): 294-304, April.-June 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-839377

RESUMO

Abstract Aneurinibacillus aneurinilyticus strain CKMV1 was isolated from rhizosphere of Valeriana jatamansi and possessed multiple plant growth promoting traits like production of phosphate solubilization (260 mg/L), nitrogen fixation (202.91 nmol ethylene mL-1 h-1), indole-3-acetic acid (IAA) (8.1 µg/mL), siderophores (61.60%), HCN (hydrogen cyanide) production and antifungal activity. We investigated the ability of isolate CKMV1 to solubilize insoluble P via mechanism of organic acid production. High-performance liquid chromatography (HPLC) study showed that isolate CKMV1 produced mainly gluconic (1.34%) and oxalic acids. However, genetic evidences for nitrogen fixation and phosphate solubilization by organic acid production have been reported first time for A. aneurinilyticus strain CKMV1. A unique combination of glucose dehydrogenase (gdh) gene and pyrroloquinoline quinone synthase (pqq) gene, a cofactor of gdh involved in phosphate solubilization has been elucidated. Nitrogenase (nif H) gene for nitrogen fixation was reported from A. aneurinilyticus. It was notable that isolate CKMV1 exhibited highest antifungal against Sclerotium rolfsii (93.58%) followed by Fusarium oxysporum (64.3%), Dematophora necatrix (52.71%), Rhizoctonia solani (91.58%), Alternaria sp. (71.08%) and Phytophthora sp. (71.37%). Remarkable increase was observed in seed germination (27.07%), shoot length (42.33%), root length (52.6%), shoot dry weight (62.01%) and root dry weight (45.7%) along with NPK (0.74, 0.36, 1.82%) content of tomato under net house condition. Isolate CKMV1 possessed traits related to plant growth promotion, therefore, could be a potential candidate for the development of biofertiliser or biocontrol agent and this is the first study to include the Aneurinibacillus as PGPR.


Assuntos
Reguladores de Crescimento de Plantas/metabolismo , Valeriana/microbiologia , Fosfatos de Cálcio/metabolismo , Solanum lycopersicum/crescimento & desenvolvimento , Bacillales/isolamento & purificação , Fixação de Nitrogênio , Microbiologia do Solo , Cromatografia Líquida de Alta Pressão , Solanum lycopersicum/microbiologia , Raízes de Plantas/microbiologia , Biomassa , Bacillales/metabolismo , Rizosfera , Fungos/crescimento & desenvolvimento , Antibiose
19.
Aging (Albany NY) ; 8(5): 1049-63, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27115295

RESUMO

Aging is an important risk factor for post-stroke infection, which accounts for a large proportion of stroke-associated mortality. Despite this, studies evaluating post-stroke infection rates in aged animal models are limited. In addition, few studies have assessed gut microbes as a potential source of infection following stroke. Therefore we investigated the effects of age and the role of bacterial translocation from the gut in post-stroke infection in young (8-12 weeks) and aged (18-20 months) C57Bl/6 male mice following transient middle cerebral artery occlusion (MCAO) or sham surgery. Gut permeability was examined and peripheral organs were assessed for the presence of gut-derived bacteria following stroke. Furthermore, sickness parameters and components of innate and adaptive immunity were examined. We found that while stroke induced gut permeability and bacterial translocation in both young and aged mice, only young mice were able to resolve infection. Bacterial species seeding peripheral organs also differed between young (Escherichia) and aged (Enterobacter) mice. Consequently, aged mice developed a septic response marked by persistent and exacerbated hypothermia, weight loss, and immune dysfunction compared to young mice following stroke.


Assuntos
Envelhecimento/metabolismo , Translocação Bacteriana/fisiologia , Isquemia Encefálica/metabolismo , Sepse/microbiologia , Acidente Vascular Cerebral/metabolismo , Imunidade Adaptativa/fisiologia , Animais , Isquemia Encefálica/complicações , Modelos Animais de Doenças , Mucosa Gástrica/metabolismo , Imunidade Inata/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Permeabilidade , Sepse/metabolismo , Acidente Vascular Cerebral/complicações
20.
J Immunol ; 196(8): 3318-30, 2016 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-26962232

RESUMO

Aging is associated with an increase in basal inflammation in the CNS and an overall decline in cognitive function and poorer recovery following injury. Growing evidence suggests that leukocyte recruitment to the CNS is also increased with normal aging, but, to date, no systematic evaluation of these age-associated leukocytes has been performed. In this work, the effect of aging on CNS leukocyte recruitment was examined. Aging was associated with more CD45(high) leukocytes, primarily composed of conventional CD8(+) T cells. These results were strain independent and seen in both sexes. Intravascular labeling and immunohistology revealed the presence of parenchymal CD8(+) T cells in several regions of the brain, including the choroid plexus and meninges. These cells had effector memory (CD44(+)CD62L(-)) and tissue-resident phenotypes and expressed markers associated with TCR activation. Analysis of TCRvß repertoire usage suggested that entry into the CNS is most likely stochastic rather than Ag driven. Correlational analyses revealed a positive association between CD8 T cell numbers and decreased proinflammatory function of microglia. However, the effects of cerebral ischemia and ex vivo stimulation of these cells dramatically increased production of TNF, IFN-γ, and MCP-1/CCL2. Taken together, we identified a novel population of resident memory, immunosurveillant CD8 T cells that represent a hallmark of CNS aging and appear to modify microglia homeostasis under normal conditions, but are primed to potentiate inflammation and leukocyte recruitment following ischemic injury.


Assuntos
Envelhecimento/imunologia , Encéfalo/imunologia , Linfócitos T CD8-Positivos/imunologia , Infarto da Artéria Cerebral Média/imunologia , Acidente Vascular Cerebral/imunologia , Fatores Etários , Animais , Biomarcadores/metabolismo , Encéfalo/patologia , Quimiocina CCL2/biossíntese , Modelos Animais de Doenças , Feminino , Receptores de Hialuronatos/metabolismo , Memória Imunológica/imunologia , Vigilância Imunológica/imunologia , Infarto da Artéria Cerebral Média/patologia , Inflamação/imunologia , Interferon gama/biossíntese , Selectina L/metabolismo , Contagem de Linfócitos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Microglia/patologia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Acidente Vascular Cerebral/patologia , Fator de Necrose Tumoral alfa/biossíntese
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA