Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 82
Filtrar
1.
J Endocrinol Invest ; 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38565814

RESUMEN

PURPOSE: According to preclinical evidence, GLP-1 receptor may be an actionable target in neurodegenerative disorders, including Alzheimer's disease (AD). Previous clinical trials of GLP-1 receptor agonists were conducted in patients with early AD, yielding mixed results. The aim was to assess in a proof-of-concept study whether slow-release exenatide, a long-acting GLP-1 agonist, can benefit the cognitive performance of people with mild cognitive impairment (MCI). METHODS: Thirty-two (16 females) patients were randomized to either slow-release exenatide (n = 17; 2 mg s.c. once a week) or no treatment (n = 15) for 32 weeks. The primary endpoint was the change in ADAS-Cog11 cognitive test score at 32 weeks vs baseline. Secondary endpoints herein reported included additional cognitive tests and plasma readouts of GLP-1 receptor engagement. Statistical analysis was conducted by intention to treat. RESULTS: No significant between-group effects of exenatide on ADAS-Cog11 score (p = 0.17) were detected. A gender interaction with treatment was observed (p = 0.04), due to worsening of the ADAS-Cog11 score in women randomized to exenatide (p = 0.018), after correction for age, scholar level, dysglycemia, and ADAS-Cog score baseline value. Fasting plasma glucose (p = 0.02) and body weight (p = 0.03) decreased in patients randomized to exenatide. CONCLUSION: In patients with MCI, a 32-week trial with slow-release exenatide had no beneficial effect on cognitive performance. TRIAL REGISTRATION NUMBER: NCT03881371, registered on 21 July, 2016.

2.
Curr Res Immunol ; 3: 199-214, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36032416

RESUMEN

In this review, the disease and immunogenicity affected by COVID-19 vaccination at the metabolic level are described considering the use of nuclear magnetic resonance (NMR) spectroscopy for the analysis of different biological samples. Consistently, we explain how different biomarkers can be examined in the saliva, blood plasma/serum, bronchoalveolar-lavage fluid (BALF), semen, feces, urine, cerebrospinal fluid (CSF) and breast milk. For example, the proposed approach for the given samples can allow one to detect molecular biomarkers that can be relevant to disease and/or vaccine interference in a system metabolome. The analysis of the given biomaterials by NMR often produces complex chemical data which can be elucidated by multivariate statistical tools, such as PCA and PLS-DA/OPLS-DA methods. Moreover, this approach may aid to improve strategies that can be helpful in disease control and treatment management in the future.

3.
Nat Commun ; 13(1): 447, 2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-35105878

RESUMEN

Trojan asteroids are small bodies orbiting around the L4 or L5 Lagrangian points of a Sun-planet system. Due to their peculiar orbits, they provide key constraints to the Solar System evolution models. Despite numerous dedicated observational efforts in the last decade, asteroid 2010 TK7 has been the only known Earth Trojan thus far. Here we confirm that the recently discovered 2020 XL5 is the second transient Earth Trojan known. To study its orbit, we used archival data from 2012 to 2019 and observed the object in 2021 from three ground-based observatories. Our study of its orbital stability shows that 2020 XL5 will remain in L4 for at least 4 000 years. With a photometric analysis we estimate its absolute magnitude to be [Formula: see text], and color indices suggestive of a C-complex taxonomy. Assuming an albedo of 0.06 ± 0.03, we obtain a diameter of 1.18 ± 0.08 km, larger than the first known Earth Trojan asteroid.

4.
Toxicol In Vitro ; 75: 105192, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33984456

RESUMEN

Targeted delivery aims to enhance cellular uptake and improve therapeutic outcome with higher disease specificity. The expression of transferrin receptor (TfR) is upregulated on tumor cells, which make the protein Tf and its receptor vastly relevant when applied to targeting strategies. Here, we proposed Tf-decorated pH-sensitive PLGA nanoparticles containing the chemosensitizer poloxamer as a carrier for doxorubicin delivery to tumor cells (Tf-DOX-PLGA-NPs), aiming at alleviating multidrug resistance (MDR). We performed a range of in vitro studies to assess whether targeted NPs have the ability to improve DOX antitumor potential on resistant NCI/ADR-RES cells. All evaluations of the Tf-decorated NPs were performed comparatively to the nontargeted counterparts, aiming to evidence the real role of NP surface functionalization, along with the benefits of pH-sensitivity and poloxamer, in the improvement of antiproliferative activity and reversal of MDR. Tf-DOX-PLGA-NPs induced higher number of apoptotic events and ROS generation, along with cell cycle arrest. Moreover, they were efficiently internalized by NCI/ADR-RES cells, increasing DOX intracellular accumulation, which supports the greater cell killing ability of these targeted NPs with respect to MDR cells. Altogether, these findings supported the effectiveness of the Tf-surface modification of DOX-PLGA-NPs for an improved antiproliferative activity. Therefore, our pH-responsive Tf-inspired NPs are a promising smart drug delivery system to overcome MDR effect at some extent, enhancing the efficacy of DOX antitumor therapy.


Asunto(s)
Antineoplásicos/administración & dosificación , Doxorrubicina/administración & dosificación , Nanopartículas/administración & dosificación , Copolímero de Ácido Poliláctico-Ácido Poliglicólico/administración & dosificación , Transferrina/administración & dosificación , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Resistencia a Múltiples Medicamentos , Resistencia a Antineoplásicos , Células HeLa , Células Hep G2 , Humanos , Concentración de Iones de Hidrógeno , Células MCF-7 , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Especies Reactivas de Oxígeno/metabolismo
5.
Opt Express ; 28(16): 23176-23188, 2020 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-32752318

RESUMEN

We investigate the impact of the photorefractive effect on lithium niobate integrated quantum photonic circuits dedicated to continuous variable on-chip experiments. The circuit main building blocks, i.e. cavities, directional couplers, and periodically poled nonlinear waveguides, are studied. This work demonstrates that photorefractivity, even when its effect is weaker than spatial mode hopping, might compromise the success of on-chip quantum photonics experiments. We describe in detail the characterization methods leading to the identification of this possible issue. We also study to which extent device heating represents a viable solution to counter this effect. We focus on photorefractive effect induced by light at 775 nm, in the context of the generation of non-classical light at 1550 nm telecom wavelength.

6.
Cytometry A ; 97(7): 662-667, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32506725

RESUMEN

SARS-CoV-2 pandemic and recurrent dengue epidemics in tropical countries have turned into a global health threat. While both virus-caused infections may only reveal light symptoms, they can also cause severe diseases. Here, we review the possible antibody-dependent enhancement (ADE) occurrence, known for dengue infections, when there is a second infection with a different virus strain. Consequently, preexisting antibodies do not neutralize infection, but enhance it, possibly by triggering Fcγ receptor-mediated virus uptake. No clinical data exist indicating such mechanism for SARS-CoV-2, but previous coronavirus infections or infection of SARS-CoV-2 convalescent with different SARS-CoV-2 strains could promote ADE, as experimentally shown for antibodies against the MERS-CoV or SARS-CoV spike S protein. © 2020 International Society for Advancement of Cytometry.


Asunto(s)
Acrecentamiento Dependiente de Anticuerpo/inmunología , Betacoronavirus/inmunología , Coinfección/inmunología , Virus del Dengue/inmunología , Receptores de IgG/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , COVID-19 , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/patología , Dengue/inmunología , Dengue/patología , Humanos , Citometría de Imagen/métodos , Coronavirus del Síndrome Respiratorio de Oriente Medio/inmunología , Pandemias , Neumonía Viral/inmunología , Neumonía Viral/patología , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/inmunología , SARS-CoV-2 , Internalización del Virus
7.
Chemosphere ; 251: 126642, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32345545

RESUMEN

The ubiquitous presence of aluminum in the environment leads to a high likelihood of human exposure. Neurotoxicity of the trivalent cationic form of this metal (Al3+) occurs in the central nervous system via accumulation of Al in cells of neural origin, including neural progenitor cells (NPCs). NPCs play a key role in the development and regeneration of the brain throughout life; therefore, this metal may contribute to neuropathological conditions. Here, we evaluated the effects of different Al3+ concentrations (0-50 µM) on the purinergic system of NPCs isolated from embryonic telencephalons, cultured as neurospheres. Al3+ adhered to the cell surface of neurospheres reducing extracellular ATP release, as well as ATP, ADP, and AMP hydrolysis by NTPDase and 5'-nucleotidase, respectively. In addition, impaired nucleotide release by Al3+ reduced P2Y1 and adenosine A2A receptors expression in differentiated neurospheres. These receptors are crucial for NPC proliferation during brain development and self-repair against external stimuli, such as metal exposure. Thus, Al3+ represents an environmental agent linked to neurodegeneration through alterations in the ATP-signalling pathway, proving to be a potential mechanism associated with NPC proliferation and brain degeneration.


Asunto(s)
Aluminio/toxicidad , 5'-Nucleotidasa , Adenosina Trifosfato/metabolismo , Aluminio/metabolismo , Animales , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Sistema Nervioso Central/metabolismo , Proteínas Ligadas a GPI , Humanos , Transducción de Señal/efectos de los fármacos , Células Madre , Pruebas de Toxicidad
8.
Stem Cell Rev Rep ; 16(3): 434-440, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32307653

RESUMEN

The expressive number of deaths and confirmed cases of SARS-CoV-2 call for an urgent demand of effective and available drugs for COVID-19 treatment. CD147, a receptor on host cells, is a novel route for SARS-CoV-2 invasion. Thus, drugs that interfere in the spike protein/CD147 interaction or CD147 expression may inhibit viral invasion and dissemination among other cells, including in progenitor/stem cells. Studies suggest beneficial effects of azithromycin in reducing viral load of hospitalized patients, possibly interfering with ligand/CD147 receptor interactions; however, its possible effects on SARS-CoV-2 invasion has not yet been evaluated. In addition to the possible effect in invasion, azithromycin decreases the expression of some metalloproteinases (downstream to CD147), induces anti-viral responses in primary human bronchial epithelial infected with rhinovirus, decreasing viral replication and release. Moreover, resident lung progenitor/stem are extensively differentiated into myofibroblasts during pulmonary fibrosis, a complication observed in COVID-19 patients. This process, and the possible direct viral invasion of progenitor/stem cells via CD147 or ACE2, could result in the decline of these cellular stocks and failing lung repair. Clinical tests with allogeneic MSCs from healthy individuals are underway to enhance endogenous lung repair and suppress inflammation.


Asunto(s)
Antibacterianos/uso terapéutico , Azitromicina/uso terapéutico , Basigina/genética , Betacoronavirus/efectos de los fármacos , Infecciones por Coronavirus/terapia , Pandemias , Neumonía Viral/terapia , Glicoproteína de la Espiga del Coronavirus/genética , Trasplante de Células Madre , Enzima Convertidora de Angiotensina 2 , Linfocitos B/efectos de los fármacos , Linfocitos B/inmunología , Linfocitos B/virología , Basigina/antagonistas & inhibidores , Basigina/inmunología , Betacoronavirus/metabolismo , Betacoronavirus/patogenicidad , COVID-19 , Ensayos Clínicos como Asunto , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/virología , Expresión Génica , Interacciones Huésped-Patógeno/efectos de los fármacos , Interacciones Huésped-Patógeno/inmunología , Humanos , Pulmón/inmunología , Pulmón/virología , Peptidil-Dipeptidasa A/genética , Peptidil-Dipeptidasa A/inmunología , Neumonía Viral/epidemiología , Neumonía Viral/inmunología , Neumonía Viral/virología , Unión Proteica/efectos de los fármacos , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus/antagonistas & inhibidores , Glicoproteína de la Espiga del Coronavirus/inmunología , Células Madre/efectos de los fármacos , Células Madre/inmunología , Células Madre/virología , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Linfocitos T/virología , Carga Viral/efectos de los fármacos
9.
Microb Pathog ; 136: 103703, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31476377

RESUMEN

Trypanosoma evansi appears to have a significant tropism for brain tissue in its chronic and acute phases. The most common symptoms of this brain infection are motor incoordination, meningoencephalitis, demyelination, and anemia. There have only been few studies of the effects of T. evansi infection on neuronal differentiation and brain plasticity. Here, we investigated the impact of the congenital T. evansi infection on brain development in mice. We collected telencephalon-derived neural progenitor cells (NPCs) from T. evansi uninfected and infected mice, and cultivated them into neurospheres. We found that T. evansi significantly decreased the number of cells during development of neurospheres. Analysis of neurosphere differentiation revealed that T. evansi infection significantly increased neural migration. We also observed that T. evansi promoted expression of glial fibrillary acidic protein (GFAP) in infected cells. These data suggest that congenital T. evansi infection may affect embryonic brain development.


Asunto(s)
Interacciones Huésped-Patógeno , Células-Madre Neurales/patología , Células-Madre Neurales/parasitología , Trypanosoma/crecimiento & desarrollo , Animales , Diferenciación Celular , Ratones
10.
Cancer Microenviron ; 12(2-3): 77-94, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31420805

RESUMEN

Tumour progression involves interactions among various cancer cell clones, including the cancer stem cell subpopulation and exogenous cellular components, termed cancer stromal cells. The latter include a plethora of tumour infiltrating immunocompetent cells, among which are also immuno-modulatory mesenchymal stem cells, which by vigorous migration to growing tumours and susequent transdifferentiation into various types of tumour-residing stromal cells, may either inhibit or support tumour progression. In the light of the scarce therapeutic options existing for the most malignant brain tumour glioblastoma, mesenchymal stem cells may represent a promising novel tool for cell therapy, e.g. drug delivery vectors. Here, we review the increasing number of reports on mutual interactions between mesenchymal stem cells and glioblastoma cells in their microenvironment. We particularly point out two novel aspects: the different responses of cancer cells to their microenvironmental cues, and to the signalling by kinin receptors that complement the immuno-modulating cytokine-signalling networks. Inflammatory glioblastoma microenvironment is characterised by increasing expression of kinin receptors during progressive glioma malignancy, thus making kinin signalling and kinins themselves rather important in this context. In general, their role in tumour microenvironment has not been explored so far. In addition, kinins also regulate blood brain barrier-related drug transfer as well as brain tumour angiogenesis. These studies support the on-going research on kinin antagonists as candidates in the development of anti-invasive agents for adjuvant glioblastoma therapy.

11.
Arch Toxicol ; 93(9): 2515-2524, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31363819

RESUMEN

Aluminum (Al) is a neurotoxin and is associated with the etiology of neurodegenerative diseases, such as Alzheimer's disease (AD). The Al-free ion (Al3+) is the biologically reactive and toxic form. However, the underlying mechanisms of Al toxicity in the brain remain unclear. Here, we evaluated the effects of Al3+ (in the chloride form-AlCl3) at different concentrations (0.1-100 µM) on the morphology, proliferation, apoptosis, migration and differentiation of neural progenitor cells (NPCs) isolated from embryonic telencephalons, cultured as neurospheres. Our results reveal that Al3+ at 100 µM reduced the number and diameter of neurospheres. Cell cycle analysis showed that Al3+ had a decisive function in proliferation inhibition of NPCs during neural differentiation and induced apoptosis on neurospheres. In addition, 1 µM Al3+ resulted in deleterious effects on neural phenotype determination. Flow cytometry and immunocytochemistry analysis showed that Al3+ promoted a decrease in immature neuronal marker ß3-tubulin expression and an increase in co-expression of the NPC marker nestin and glial fibrillary acidic protein. Thus, our findings indicate that Al3+ caused cellular damage and reduced proliferation and migration, resulting in global inhibition of NPC differentiation and neurogenesis.


Asunto(s)
Cloruro de Aluminio/toxicidad , Células Madre Embrionarias/efectos de los fármacos , Células-Madre Neurales/efectos de los fármacos , Neurogénesis/efectos de los fármacos , Animales , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Células Madre Embrionarias/patología , Femenino , Masculino , Ratones , Células-Madre Neurales/patología , Síndromes de Neurotoxicidad/etiología , Síndromes de Neurotoxicidad/fisiopatología , Fenotipo , Telencéfalo/efectos de los fármacos , Telencéfalo/embriología
12.
Microb Pathog ; 132: 156-161, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31029718

RESUMEN

Chagas disease (CD) affecting about 7 million people is caused by the flagellate protozoan Trypanosoma cruzi. The central nervous system (CNS) is an important site for T. cruzi persistence in the host during the chronic phase of infection, because the protozoan may pass the blood-brain barrier and may cause motor and cognitive neuronal damage. Thinking about avoiding or minimizing these negative effects, it is hypothesized that resveratrol (RSV), a component with several medicinal properties has beneficial effects on the CNS. The objective of this study was to investigate, whether T. cruzi infection interferes with neurogenesis and gliogenesis of embryos of infected mice females, and whether RSV would be able to avoid or minimize these changes caused by CD. RSV is a polyphenol found in grapes and widely studied for its neuroprotective and antioxidant properties. In addition, we investigated the role caused by the parasite during congenital infection and CNS development. Embryos and their brains were PCR-positive for T. cruzi. For this study, NPCs obtained from telencephalon of infected and uninfected embryos and were cultured in presence of resveratrol for forming neurospheres. The results demonstrated that the congenital transmission of T. cruzi influences CNS formation and neural fate, decreasing the number of neuroespheres and causing an elongation in the phases of the cell cycle. In addition, the parasite promoted an increase in neugliogenesis. Resveratrol was neuroprotective and prevented negative effects of the infection. Thus, we suggest the use of resveratrol as a therapeutic target for the treatment of neuroinflammation or as neuroprotective agent during Chagas disease, as it improves gliogenesis and restores neural migration.


Asunto(s)
Diferenciación Celular/efectos de los fármacos , Neuronas/efectos de los fármacos , Resveratrol/farmacología , Células Madre/efectos de los fármacos , Animales , Enfermedad de Chagas/tratamiento farmacológico , Modelos Animales de Enfermedad , Femenino , Ratones , Neurogénesis/efectos de los fármacos , Neuronas/citología , Células Madre/metabolismo , Trypanosoma cruzi
13.
Mol Neurobiol ; 56(4): 2328-2338, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30027338

RESUMEN

The intracellular protozoan Toxoplasma gondii may cause congenital toxoplasmosis and serious brain damage in fetus. However, the underlying mechanism of neuropathogenesis in brain toxoplasmosis remains unclear. For this study, neural progenitor cells (NPCs) were obtained from embryo telencephalons (embryonic day 13) and induced to proliferation in the presence of growth factors (GFs). For gathering insights into the biological effects of resveratrol (RSV) on neurogenesis, this study aimed to investigate effects of RSV concentrations (0.1 to 100 µM) on proliferation, migration and differentiation of NPCs infected by T. gondii. T. gondii infection increased the presence of cells in Sub G1 phase, reducing the global frequency of undifferentiated cells in S and G2/M phases of cell cycle and reduced cell viability/mithochondrial activity of infected NPCs. Moreover T. gondii stimulated neural migration and gliogenesis during neutral differentation. However, the treatment with RSV stimulated cell proliferation, restored cellular viability of infected NPCs and exerted an inhibitory effect on gliogenesis of infected NPCs favorecing neuronal maturation during toxoplasmosis infection. Thus, we have successfully to demonstrated that RSV is promising as therapeutic for congenital toxoplasmosis.


Asunto(s)
Células-Madre Neurales/parasitología , Neurogénesis/efectos de los fármacos , Neuroglía/patología , Resveratrol/farmacología , Toxoplasma/fisiología , Animales , Encéfalo/crecimiento & desarrollo , Encéfalo/parasitología , Encéfalo/patología , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Femenino , Transmisión Vertical de Enfermedad Infecciosa , Ratones , Células-Madre Neurales/efectos de los fármacos , Neuroglía/efectos de los fármacos , Esferoides Celulares/efectos de los fármacos , Esferoides Celulares/metabolismo
14.
Purinergic Signal ; 15(1): 77-84, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30535987

RESUMEN

The effects of Toxoplasma gondii during embryonic development have not been explored despite the predilection of this parasite for neurons and glial cells. Here, we investigated the activation of the purinergic system and proinflammatory responses during congenital infection by T. gondii. Moreover, neuroprotective and neuromodulatory properties of resveratrol (RSV), a polyphenolic natural compound, were studied in infected neuronal progenitor cells (NPCs). For this study, NPCs were isolated from the telencephalon of infected mouse embryos and subjected to neurosphere culture in the presence of EGF and FGF2. ATP hydrolysis and adenosine deamination by adenosine deaminase activity were altered in conditions of T. gondii infection. P2X7 and adenosine A2A receptor expression rates were augmented in infected NPCs together with an increase of proinflammatory (INF-γ and TNF-α) and anti-inflammatory (IL-10) cytokine gene expression. Our results confirm that RSV counteracted T. gondii-promoted effects on enzymes hydrolyzing extracellular nucleotides and nucleosides and also upregulated P2X7 and A2A receptor expression and activity, modulating INF-γ, TNF-α, and IL-10 cytokine production, which plays an integral role in the immune response against T. gondii.


Asunto(s)
Antioxidantes/farmacología , Células-Madre Neurales , Receptor de Adenosina A2A/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Resveratrol/farmacología , Toxoplasmosis/metabolismo , Animales , Femenino , Ratones , Células-Madre Neurales/efectos de los fármacos , Células-Madre Neurales/inmunología , Células-Madre Neurales/microbiología , Embarazo , Efectos Tardíos de la Exposición Prenatal/microbiología , Purinas/metabolismo , Receptor de Adenosina A2A/inmunología , Receptores Purinérgicos P2X7/inmunología , Toxoplasmosis/inmunología
15.
Pesqui. vet. bras ; 38(12): 2183-2189, dez. 2018. ilus
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-976422

RESUMEN

Adipose tissue-derived stem cells (ADSCs) are an attractive source of mesenchymal stem cells (MSCs) for use in tissue engineering and clinical applications. This paper focuses on the characterization of ADSCs used as immunosuppressive agent in rabbits undergoing partial allograft for urine bladder restorage. For this study highlighted the characterization of the ADSCs used as immunosuppressive agents in rabbits submitted to partial allograft for restoration of the urinary vesicle, using 25 animals, six months old, New Zealand. ADSCs at the third peal were characterized by the MSC-specific CD105, CD73 and CD90 expression and by the absence of the hematopoietic marker CD45, as revealed by flow cytometry analysis. Moreover, ADSCs were efficient in preventing allograft rejection from the urinary bladder, as judged by biochemical, clinical and ultrasonography analysis. Together, these results compose characterization of protein expression profiles and immunosuppressive functionality of ADSCs in rabbits, which had undergone partial allografts of the urinary bladder, foreseeing future applications in clinical practice.(AU)


As células mesenquimais derivadas de tecido adiposo (ADSCs) são uma fonte atraente de células-tronco mesenquimais (MSCs) para uso na engenharia de tecidos e suas aplicações clínicas. Este trabalho destacou a caracterização das ADSCs utilizadas como agentes imunossupressores em coelhos submetidos a aloenxerto parcial para restauração da vesícula urinária, sendo utilizados 25 animais, de seis meses de idade, Nova Zelândia. As ADSCs, após o terceiro repique, foram caracterizadas pela expressão específica de MSC CD105, CD73 e CD90 e pela ausência do marcador hematopoiético CD45, tal como revelado por análise de citometria de fluxo. Além disso, os ADSCs foram eficientes na prevenção da rejeição de aloenxertos da vesícula urinária, conforme avaliado por análises clínica, bioquímica e ultrassonográfica. Juntos, esses resultados compõem a caracterização dos perfis de expressão proteica e a funcionalidade imunossupressora de ADSCs em coelhos, que sofreram aloenxertos parciais da bexiga, prevendo futuras aplicações na prática clínica.(AU)


Asunto(s)
Animales , Conejos , Conejos , Vejiga Urinaria/trasplante , Aloinjertos/citología , Tratamiento Basado en Trasplante de Células y Tejidos/veterinaria , Inmunosupresores , Citometría de Flujo/veterinaria
16.
Opt Express ; 26(21): 27058-27063, 2018 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-30469780

RESUMEN

Light routing and manipulation are important aspects of integrated optics. They essentially rely on beam splitters which are at the heart of interferometric setups and active routing. The most common implementations of beam splitters suffer either from strong dispersive response (directional couplers) or tight fabrication tolerances (multimode interference couplers). In this paper we fabricate a robust and simple broadband integrated beam splitter based on lithium niobate with a splitting ratio achromatic over more than 130 nm. Our architecture is based on spatial adiabatic passage, a technique originally used to transfer entirely an optical beam from a waveguide to another one that has been shown to be remarkably robust against fabrication imperfections and wavelength dispersion. Our device shows a splitting ratio of 0.52±0.03 and 0.48±0.03 from 1500 nm up to 1630 nm. Furthermore, we show that suitable design enables the splitting in output beams with relative phase 0 or π. Thanks to their independence to material dispersion, these devices represent simple, elementary components to create achromatic and versatile photonic circuits.

17.
Front Pharmacol ; 9: 500, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29867502

RESUMEN

Bone marrow metastasis occurs in approximately 350,000 patients that annually die in the U.S. alone. In view of the importance of tumor cell migration into the bone marrow, we have here investigated effects of various concentrations of stromal cell-derived factor-1 (SDF-1), bradykinin- and ATP on bone marrow metastasis. We show for first time that bradykinin augmented chemotactic responsiveness of neuroblastoma cells to SDF-1 and ATP concentrations, encountered under physiological conditions. Bradykinin upregulated VEGF expression, increased metalloproteinase activity and induced adhesion of neuroblastoma cells. Bradykinin augmented SDF-1-induced intracellular Ca2+ mobilization as well as resensitization and expression of ATP-sensing P2X7 receptors. Bradykinin treatment resulted in higher gene expression levels of the truncated P2X7B receptor compared to those of the P2X7A full-length isoform. Bradykinin as pro-metastatic factor induced tumor proliferation that was significantly decreased by P2X7 receptor antagonists; however, the peptide did not enhance cell death nor P2X7A receptor-related pore activity, promoting neuroblastoma growth. Furthermore, immunodeficient nude/nude mice transplanted with bradykinin-pretreated neuroblastoma cells revealed significantly higher metastasis rates compared to animals injected with untreated cells. In contrast, animals receiving Brilliant Blue G, a P2X7 receptor antagonist, did not show any specific dissemination of neuroblastoma cells to the bone marrow and liver, and metastasis rates were drastically reduced. Our data suggests correlated actions of kinins and purines in neuroblastoma dissemination, providing novel avenues for clinic research in preventing metastasis.

18.
Front Pharmacol ; 9: 325, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29692728

RESUMEN

Since proving adenosine triphosphate (ATP) functions as a neurotransmitter in neuron/glia interactions, the purinergic system has been more intensely studied within the scope of the central nervous system. In neurological disorders with associated motor symptoms, including Parkinson's disease (PD), motor neuron diseases (MND), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), Huntington's Disease (HD), restless leg syndrome (RLS), and ataxias, alterations in purinergic receptor expression and activity have been noted, indicating a potential role for this system in disease etiology and progression. In neurodegenerative conditions, neural cell death provokes extensive ATP release and alters calcium signaling through purinergic receptor modulation. Consequently, neuroinflammatory responses, excitotoxicity and apoptosis are directly or indirectly induced. This review analyzes currently available data, which suggests involvement of the purinergic system in neuro-associated motor dysfunctions and underlying mechanisms. Possible targets for pharmacological interventions are also discussed.

19.
Neurobiol Learn Mem ; 149: 135-143, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29458098

RESUMEN

Lipopolysaccharide (LPS) has been long known to promote neuroinflammation and learning and memory deficits. Since spermine, one of the main natural polyamines in the central nervous system, protects from LPS-induced memory deficit by a mechanism that comprises GluN2B receptors, the aim of the present study was to determine whether brain-derived neurotrophic factor (BDNF), tropomyosin-related kinase B (TrkB) receptor and cAMP response element binding (CREB) are involved in this protective effect of spermine. Adult male Swiss albino mice received, immediately after training in the novel object recognition task, saline or LPS (250 µg/kg, i.p.); 5 min later they received saline or spermine (0.3 mg/kg, i.p.) and, when specified, 5 min thereafter saline or the TrkB receptor antagonist ANA-12 (0.5 mg/kg, i.p.) in different flanks. Animals were tested 24 h after training. Spermine protected from LPS-induced memory deficit and this protective effect was reversed by ANA-12. In a subset of animals BDNF, CREB and phospho-CREB immunoreactivity was determined in the hippocampi and cerebral cortex 4 h after spermine injection. Spermine reversed the decrease of mature BDNF levels induced by LPS in both hippocampus and cerebral cortex. Spermine increased phospho-CREB content and phospho-CREB/total CREB ratio in the cerebral cortex of LPS-treated mice. The results support that the protective effect of spermine on LPS-induced memory deficits depends on TrkB receptor activation and is accompanied by restoration of mature BDNF levels in hippocampus and cerebral cortex, as well as increased CREB phosphorylation in the cerebral cortex.


Asunto(s)
Factor Neurotrófico Derivado del Encéfalo/metabolismo , Hipocampo/efectos de los fármacos , Glicoproteínas de Membrana/metabolismo , Trastornos de la Memoria/metabolismo , Fármacos Neuroprotectores/farmacología , Proteínas Tirosina Quinasas/metabolismo , Espermina/farmacología , Animales , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Hipocampo/metabolismo , Lipopolisacáridos , Masculino , Trastornos de la Memoria/inducido químicamente , Ratones , Fosforilación/efectos de los fármacos , Transducción de Señal/efectos de los fármacos
20.
Sci Rep ; 8(1): 1299, 2018 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-29358738

RESUMEN

Glioblastoma multiforme (GBM) represents the most lethal brain tumour, and these tumours have very limited treatment options. Mesenchymal stem cells (MSC) are considered as candidates for advanced cell therapies, due to their tropism towards GBM, possibly affecting their malignancy, thus also representing a potential therapeutic vector. Therefore, we aimed to compare the effects of bone-marrow-derived versus adipose-tissue-derived MSC (BM-/AT-MSC) on heterogeneous populations of tumour cells. This cells' interplay was addressed by the in-vitro two-dimensional (monolayer) and three-dimensional (spheroid) co-culture models, using U87 and U373 GBM cell lines, expressing genotypically different mesenchymal transcriptome profiles. U87 cell low mesenchymal profile expressed high levels of kinin receptor 1 (B1R) and their invasion was greatly enhanced by the B1R agonist des-Arg9-bradykinin upon BM-MSC co-culturing in 3D co-cultures. This correlated to significantly higher cell-cell interactions in U87/BM-MSC mixed spheroids. This was not observed with the U373 cells and not in AT-MSC co-cultures. Altogether, these data support the on-going exploration of B1R as target for adjuvant approach in GBM therapy. Secondly, the results emphasize the need for further careful exploration of the selectivity regarding the origin of MSC as potential candidates for cell therapies, particular in cancer, where they may adversely affect heterogeneous tumour cell populations.


Asunto(s)
Bradiquinina/análogos & derivados , Comunicación Celular/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Neuroglía/efectos de los fármacos , Receptor de Bradiquinina B1/agonistas , Esferoides Celulares/metabolismo , Tejido Adiposo/citología , Tejido Adiposo/efectos de los fármacos , Tejido Adiposo/metabolismo , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/metabolismo , Bradiquinina/farmacología , Diferenciación Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Técnicas de Cocultivo , Humanos , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/metabolismo , Neuroglía/metabolismo , Neuroglía/patología , Especificidad de Órganos , Receptor de Bradiquinina B1/metabolismo , Esferoides Celulares/citología , Esferoides Celulares/efectos de los fármacos , Técnicas de Cultivo de Tejidos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...