RESUMEN
ß-Cyclodextrin (ß-CD) is being considered a promising therapy for Niemann-Pick C (NPC) disease because of its ability to mobilise the entrapped cholesterol from lysosomes, however, a major limitation is its inability to cross the blood-brain barrier (BBB) and address the central nervous system (CNS) manifestations of the disease. Considering this, we aimed to design nanoparticles able to cross the BBB and deliver ß-CD into the CNS lysosomes. The physicochemical characteristics of ß-CD-loaded nanoparticles were evaluated by dynamic light scattering, small-angle X-ray scattering, and cryogenic transmission electron microscopy. The in vitro analyses were performed with NPC dermal fibroblasts and the ß-CD-loaded nanoparticles were tracked in vivo. The nanoparticles showed a mean diameter around 120 nm with a disordered bicontinuous inner structure. The nanoparticles did not cause decrease in cell viability, impairment in the antioxidant enzymes activity, damage to biomolecules or release of reactive species in NPC dermal fibroblasts; also, they did not induce genotoxicity or alter the mitochondrial function in healthy fibroblasts. The ß-CD-loaded nanoparticles were taken up by lysosomes reducing the cholesterol accumulated in NPC fibroblasts and reached the CNS of mice more intensely than other organs, demonstrating advantages compared to the free ß-CD. The results demonstrated the potential of the ß-CD-loaded nanoparticles in reducing the brain impairment of NPC.
Asunto(s)
Colesterol/metabolismo , Nanopartículas/administración & dosificación , Enfermedad de Niemann-Pick Tipo C/tratamiento farmacológico , beta-Ciclodextrinas/administración & dosificación , Animales , Transporte Biológico , Estudios de Casos y Controles , Niño , Femenino , Fibroblastos/efectos de los fármacos , Humanos , Lisosomas/metabolismo , Masculino , Ratones , Enfermedad de Niemann-Pick Tipo C/metabolismo , beta-Ciclodextrinas/farmacologíaRESUMEN
Inflammation is the principal response invoked by the body to address injuries. Despite inflammation constituting a crucial component of tissue repair, it is well known that unchecked or chronic inflammation becomes deleterious, leading to progressive tissue damage. Studies over the past years focused on foods rich in polyphenols with anti-inflammatory and immunomodulatory properties, since inflammation was recognized to play a central role in several diseases. In this review, we discuss the beneficial effects of resveratrol, the most widely investigated polyphenol, on cancer and neurodegenerative, respiratory, metabolic, and cardiovascular diseases. We highlight how resveratrol, despite its unfavorable pharmacokinetics, can modulate the inflammatory pathways underlying those diseases, and we identify future opportunities for the evaluation of its clinical feasibility.
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Antiinflamatorios no Esteroideos/administración & dosificación , Antiinflamatorios no Esteroideos/farmacocinética , Estilbenos/administración & dosificación , Estilbenos/farmacocinética , Animales , Enfermedades Cardiovasculares/dietoterapia , Enfermedades Cardiovasculares/tratamiento farmacológico , Ensayos Clínicos como Asunto , Humanos , Inflamación/dietoterapia , Inflamación/tratamiento farmacológico , Ratones , Neoplasias/dietoterapia , Neoplasias/tratamiento farmacológico , Obesidad/dietoterapia , Obesidad/tratamiento farmacológico , Ratas , Enfermedades Respiratorias/dietoterapia , Enfermedades Respiratorias/tratamiento farmacológico , ResveratrolRESUMEN
Glioblastoma (GBM) stands as the most aggressive and lethal among the main types of primary brain tumors. It exhibits malignant growth, infiltrating the brain tissue, and displaying resistance toward treatment. GBM is a complex disease characterized by high degrees of heterogeneity. During tumour growth, microglia and astrocytes, among other cells, infiltrate the tumour microenvironment and contribute extensively to gliomagenesis. Tumour-associated macrophages (TAMs), either of peripheral origin or representing brain-intrinsic microglia, are the most numerous nonneoplastic populations in the tumour microenvironment in GBM. The complex heterogeneous nature of GBM cells is facilitated by the local inflammatory tumour microenvironment, which mostly induces tumour aggressiveness and drug resistance. The immunosuppressive tumour microenvironment of GBM provides multiple pathways for tumour immune evasion, contributing to tumour progression. Additionally, TAMs and astrocytes can contribute to tumour progression through the release of cytokines and activation of signalling pathways. In this review, we summarize the role of the microenvironment in GBM progression, focusing on neuroinflammation. These recent advancements in research of the microenvironment hold the potential to offer a promising approach to the treatment of GBM in the coming times.
Asunto(s)
Neoplasias Encefálicas , Progresión de la Enfermedad , Glioblastoma , Enfermedades Neuroinflamatorias , Microambiente Tumoral , Humanos , Glioblastoma/patología , Glioblastoma/inmunología , Glioblastoma/tratamiento farmacológico , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/inmunología , Neoplasias Encefálicas/metabolismo , Enfermedades Neuroinflamatorias/patología , Enfermedades Neuroinflamatorias/inmunología , Astrocitos/patología , Astrocitos/metabolismo , Astrocitos/inmunología , Animales , Macrófagos Asociados a Tumores/inmunología , Macrófagos Asociados a Tumores/metabolismo , Macrófagos Asociados a Tumores/patología , Transducción de Señal , Microglía/patología , Microglía/inmunologíaRESUMEN
Infection by SARS-CoV-2 is associated with uncontrolled inflammatory response during COVID-19 severe disease, in which monocytes are one of the main sources of pro-inflammatory mediators leading to acute respiratory distress syndrome. Extracellular vesicles (EVs) from different cells play important roles during SARS-CoV-2 infection, but investigations describing the involvement of EVs from primary human monocyte-derived macrophages (MDM) on the regulation of this infection are not available. Here, we describe the effects of EVs released by MDM stimulated with the neuropeptides VIP and PACAP on SARS-CoV-2-infected monocytes. MDM-derived EVs were isolated by differential centrifugation of medium collected from cells cultured for 24 h in serum-reduced conditions. Based on morphological properties, we distinguished two subpopulations of MDM-EVs, namely large (LEV) and small EVs (SEV). We found that MDM-derived EVs stimulated with the neuropeptides inhibited SARS-CoV-2 RNA synthesis/replication in monocytes, protected these cells from virus-induced cytopathic effects and reduced the production of pro-inflammatory mediators. In addition, EVs derived from VIP- and PACAP-treated MDM prevented the SARS-CoV-2-induced NF-κB activation. Overall, our findings suggest that MDM-EVs are endowed with immunoregulatory properties that might contribute to the antiviral and anti-inflammatory responses in SARS-CoV-2-infected monocytes and expand our knowledge of EV effects during COVID-19 pathogenesis.
RESUMEN
Alzheimer's disease (AD), a neurodegenerative disorder exhibiting progressive loss of memory and cognitive functions, is characterized by the presence of neuritic plaques composed of neurofibrillary tangles and ß-amyloid (Aß) peptide. Drug delivery to the brain still remains highly challenging for the treatment of AD. Several studies have been shown that curcumin is associated with anti-amyloidogenic properties, but therapeutic application of its beneficial effects is limited. Here we investigated possible mechanisms involved in curcumin protection against Aß(1-42)-induced cognitive impairment and, due to its poor bioavailability, we developed curcumin-loaded lipid-core nanocapsules in an attempt to improve the neuroprotective effect of this polyphenol. Animals received a single intracerebroventricular injection of Aß(1-42) and they were administered either free curcumin or curcumin-loaded lipid-core nanocapsules (Cur-LNC) intraperitoneally for 10days. Aß(1-42)-infused animals showed a significant impairment on learning-memory ability, which was paralleled by a significant decrease in hippocampal synaptophysin levels. Furthermore, animals exhibited activated astrocytes and microglial cells, as well as disturbance in BDNF expression and Akt/GSK-3ß signaling pathway, beyond tau hyperphosphorylation. Our findings demonstrate that administration of curcumin was effective in preventing behavioral impairments, neuroinflammation, tau hyperphosphorylation as well as cell signaling disturbances triggered by Aß in vivo. Of high interest, Cur-LNC in a dose 20-fold lower presented similar neuroprotective results compared to the effective dose of free curcumin. Considered overall, the data suggest that curcumin is a potential therapeutic agent for neurocognition and nanoencapsulation of curcumin in LNC might constitute a promising therapeutic alternative in the treatment of neurodegenerative diseases such as AD.
Asunto(s)
Factor Neurotrófico Derivado del Encéfalo/metabolismo , Trastornos del Conocimiento/tratamiento farmacológico , Curcumina/uso terapéutico , Glucógeno Sintasa Quinasa 3/metabolismo , Memoria/efectos de los fármacos , Fármacos Neuroprotectores/uso terapéutico , Proteínas Proto-Oncogénicas c-akt/metabolismo , Péptidos beta-Amiloides , Animales , Cognición/efectos de los fármacos , Trastornos del Conocimiento/inducido químicamente , Trastornos del Conocimiento/metabolismo , Curcumina/farmacología , Glucógeno Sintasa Quinasa 3 beta , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Masculino , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Fármacos Neuroprotectores/farmacología , Ratas , Ratas Wistar , Transducción de Señal/efectos de los fármacos , Sinaptofisina/metabolismoRESUMEN
This study was undertaken to evaluate the effects of chronic variate stress and lithium treatment on glutamatergic activity and neuronal vulnerability of rat hippocampus. Male Wistar rats were simultaneously treated with lithium and submitted to a chronic variate stress protocol during 40 days, and afterwards the hippocampal glutamatergic uptake and release, measured in slices and synaptosomes, were evaluated. We observed an increased synaptosomal [(3)H]glutamate uptake and an increase in [(3)H]glutamate stimulated release in hippocampus of lithium-treated rats. Chronic stress increased basal [(3)H]glutamate release by synaptosomes, and decreased [(3)H]glutamate uptake in hippocampal slices. When evaluating cellular vulnerability, both stress and lithium increased cellular death after oxygen and glucose deprivation (OGD). We suggest that the manipulation of glutamatergic activity induced by stress may be in part responsible for the neuroendangerment observed after stress exposure, and that, in spite of the described neuroprotective effects of lithium, it increased the neuronal vulnerability after OGD.
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Muerte Celular/efectos de los fármacos , Glucosa/metabolismo , Ácido Glutámico/metabolismo , Hipocampo/efectos de los fármacos , Hipoxia/metabolismo , Compuestos de Litio/farmacología , Estrés Fisiológico , Animales , Enfermedad Crónica , Hipocampo/enzimología , Hipocampo/metabolismo , Hipocampo/patología , L-Lactato Deshidrogenasa/metabolismo , Masculino , Necrosis , Ratas , Ratas WistarRESUMEN
Alzheimer's disease (AD) is a progressive neurodegenerative disorder marked by accumulation of extracellular deposits of amyloid-beta (Abeta) peptide in brain regions that are important for memory and cognition. The buildup of Abeta aggregates in the AD is followed by the formation of intracellular neurofibrillary tangles and activation of neuroinflammatory reactions. The present study investigated whether melatonin possesses a neuroprotective effect against Abeta-induced toxicity. For this purpose, organotypic hippocampal slices were cultured and exposed to 25 microm of Abeta(25-35) in the absence or in the presence of melatonin (25, 50, or 100 microm). In addition, the authors have investigated the involvement of GSK-3beta, tau protein, astroglial, and microglial activation, and cytokine levels in the melatonin protection against Abeta-induced neurotoxicity. Melatonin prevented the cell damage in hippocampus induced by the exposure to Abeta(25-35). In addition, melatonin significantly reduced the activation of GSK-3beta, the phosphorylation of tau protein, the glial activation and the Abeta-induced increase of TNF-alpha and IL-6 levels. On the basis of these findings, we speculate that melatonin may provide an effective therapeutic strategy for AD, by attenuating Abeta-induced phosphorylation of tau protein, and preventing GSK-3beta activation and neuroinflammation.
Asunto(s)
Péptidos beta-Amiloides/antagonistas & inhibidores , Glucógeno Sintasa Quinasa 3/metabolismo , Melatonina/farmacología , Proteínas tau/metabolismo , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/toxicidad , Análisis de Varianza , Animales , Astrocitos/efectos de los fármacos , Astrocitos/metabolismo , Astrocitos/patología , Muerte Celular/efectos de los fármacos , Glucógeno Sintasa Quinasa 3 beta , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Hipocampo/patología , Histocitoquímica , Interleucina-6/metabolismo , Masculino , Proteínas del Tejido Nervioso/metabolismo , Propidio/metabolismo , Ratas , Ratas Wistar , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
A substantial body of evidence supports that the gut microbiota plays a pivotal role in the regulation of metabolic, endocrine and immune functions. In recent years, there has been growing recognition of the involvement of the gut microbiota in the modulation of multiple neurochemical pathways through the highly interconnected gut-brain axis. Although amazing scientific breakthroughs over the last few years have expanded our knowledge on the communication between microbes and their hosts, the underpinnings of microbiota-gut-brain crosstalk remain to be determined. Short-chain fatty acids (SCFAs), the main metabolites produced in the colon by bacterial fermentation of dietary fibers and resistant starch, are speculated to play a key role in neuro-immunoendocrine regulation. However, the underlying mechanisms through which SCFAs might influence brain physiology and behavior have not been fully elucidated. In this review, we outline the current knowledge about the involvement of SCFAs in microbiota-gut-brain interactions. We also highlight how the development of future treatments for central nervous system (CNS) disorders can take advantage of the intimate and mutual interactions of the gut microbiota with the brain by exploring the role of SCFAs in the regulation of neuro-immunoendocrine function.
Asunto(s)
Encéfalo/fisiología , Comunicación Celular/fisiología , Ácidos Grasos Volátiles/fisiología , Microbioma Gastrointestinal/fisiología , Intestinos/fisiología , Animales , HumanosRESUMEN
Malignant gliomas are the most common and devastating primary tumors of the central nervous system. Currently no efficient treatment is available. This study evaluated the effect and underlying mechanisms of boldine, an aporphine alkaloid of Peumus boldus, on glioma proliferation and cell death. Boldine decreased the cell number of U138-MG, U87-MG and C6 glioma lines at concentrations of 80, 250 and 500 muM. We observed that cell death caused by boldine was cell-type specific and dose-dependent. Exposure to boldine for 24 h did not activate key mediators of apoptosis. However, it induced alterations in the cell cycle suggesting a G(2)/M arrest in U138-MG cells. Boldine had no toxic effect on non-tumor cells when used at the same concentrations as those used on tumor cells. Based on these results, we speculate that boldine may be a promising compound for evaluation as an anti-cancer agent.
Asunto(s)
Antineoplásicos/uso terapéutico , Aporfinas/farmacología , Aporfinas/uso terapéutico , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/patología , Glioma/tratamiento farmacológico , Glioma/patología , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Aporfinas/química , Encéfalo/efectos de los fármacos , Encéfalo/patología , Neoplasias Encefálicas/enzimología , Caspasa 3/metabolismo , Caspasa 9/metabolismo , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Daño del ADN , Ensayos de Selección de Medicamentos Antitumorales , Puntos de Control de la Fase G2 del Ciclo Celular/efectos de los fármacos , Glioma/enzimología , Humanos , Técnicas In Vitro , Masculino , Mitosis/efectos de los fármacos , Ratas , Ratas WistarRESUMEN
Cell therapy using bone marrow-derived mesenchymal stem cells (MSC) seems to be a new alternative for the treatment of neurological diseases, including stroke. In order to investigate the response of hippocampal tissue to factors secreted by MSC and if these factors are neuroprotective in a model of oxygen and glucose deprivation (OGD), we used organotypic hippocampal cultures exposed to conditioned medium from bone marrow-derived MSC. Our results suggest that the conditioned medium obtained from these cells aggravates lesion caused by OGD. In addition, the presence of the conditioned medium alone was toxic mainly to cells in the CA1, CA2 and CA3 areas of the hippocampal organotypic culture even in basal conditions. GABA stimulation and NMDA and AMPA receptors antagonists were able to reduce propidium iodide staining, suggesting that the cell death induced by the toxic factors secreted by MSC could involve these receptors.
Asunto(s)
Medios de Cultivo Condicionados/toxicidad , Hipocampo/efectos de los fármacos , Hipoxia-Isquemia Encefálica/terapia , Trasplante de Células Madre Mesenquimatosas/efectos adversos , Células Madre Mesenquimatosas/metabolismo , Degeneración Nerviosa/inducido químicamente , Animales , Muerte Celular/efectos de los fármacos , Muerte Celular/fisiología , Células Cultivadas , Antagonistas de Aminoácidos Excitadores/farmacología , Ácido Glutámico/metabolismo , Hipocampo/metabolismo , Hipocampo/fisiopatología , Hipoxia-Isquemia Encefálica/metabolismo , Hipoxia-Isquemia Encefálica/fisiopatología , Masculino , Degeneración Nerviosa/metabolismo , Degeneración Nerviosa/fisiopatología , Técnicas de Cultivo de Órganos , Propidio , Ratas , Ratas Wistar , Receptores AMPA/efectos de los fármacos , Receptores AMPA/metabolismo , Receptores de N-Metil-D-Aspartato/efectos de los fármacos , Receptores de N-Metil-D-Aspartato/metabolismo , Ácido gamma-Aminobutírico/metabolismo , Ácido gamma-Aminobutírico/farmacologíaRESUMEN
Accumulation of the neurotoxic amyloid beta-peptide (Abeta) in the brain is a hallmark of Alzheimer's disease (AD). Several synthetic Abeta peptides have been used to study the mechanisms of toxicity. Here, we sought to establish comparability between two commonly used Abeta peptides Abeta1-42 and Abeta25-35 on an in vitro model of Abeta toxicity. For this purpose we used organotypic slice cultures of rat hippocampus and observed that both Abeta peptides caused similar toxic effects regarding to propidium iodide uptake and caspase-3 activation. In addition, we also did not observe any effect of both peptides on Akt and PTEN phosphorylation; otherwise the phosphorylation of GSK-3beta was increased. Although further studies are necessary for understanding mechanisms underlying Abeta peptide toxicity, our results provide strong evidence that Abeta1-42 and the Abeta25-35 peptides induce neural injury in a similar pattern and that Abeta25-35 is a convenient tool for the investigation of neurotoxic mechanisms involved in AD.
Asunto(s)
Péptidos beta-Amiloides/toxicidad , Hipocampo/efectos de los fármacos , Fragmentos de Péptidos/toxicidad , Animales , Western Blotting , Caspasa 3/metabolismo , Activación Enzimática , Glucógeno Sintasa Quinasa 3/metabolismo , Glucógeno Sintasa Quinasa 3 beta , Hipocampo/enzimología , Hipocampo/metabolismo , Técnicas In Vitro , Fosfohidrolasa PTEN/metabolismo , Fosforilación , Proteínas Proto-Oncogénicas c-akt/metabolismo , RatasRESUMEN
Defective brain hormonal signaling has been associated with Alzheimer's disease (AD), a disorder characterized by synapse and memory failure. Irisin is an exercise-induced myokine released on cleavage of the membrane-bound precursor protein fibronectin type III domain-containing protein 5 (FNDC5), also expressed in the hippocampus. Here we show that FNDC5/irisin levels are reduced in AD hippocampi and cerebrospinal fluid, and in experimental AD models. Knockdown of brain FNDC5/irisin impairs long-term potentiation and novel object recognition memory in mice. Conversely, boosting brain levels of FNDC5/irisin rescues synaptic plasticity and memory in AD mouse models. Peripheral overexpression of FNDC5/irisin rescues memory impairment, whereas blockade of either peripheral or brain FNDC5/irisin attenuates the neuroprotective actions of physical exercise on synaptic plasticity and memory in AD mice. By showing that FNDC5/irisin is an important mediator of the beneficial effects of exercise in AD models, our findings place FNDC5/irisin as a novel agent capable of opposing synapse failure and memory impairment in AD.
Asunto(s)
Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/fisiopatología , Fibronectinas/metabolismo , Trastornos de la Memoria/complicaciones , Trastornos de la Memoria/fisiopatología , Plasticidad Neuronal , Condicionamiento Físico Animal , Adolescente , Adulto , Anciano , Enfermedad de Alzheimer/líquido cefalorraquídeo , Enfermedad de Alzheimer/genética , Animales , Encéfalo/metabolismo , Encéfalo/patología , Modelos Animales de Enfermedad , Regulación hacia Abajo , Femenino , Fibronectinas/líquido cefalorraquídeo , Fibronectinas/genética , Humanos , Potenciación a Largo Plazo , Masculino , Ratones Endogámicos C57BL , Persona de Mediana Edad , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas Recombinantes/farmacología , Proteínas Recombinantes/uso terapéutico , Transducción de SeñalRESUMEN
Gliomas are the most common and devastating tumors of the central nervous system. Several studies have suggested that nonsteroidal anti-inflammatory drugs (NSAIDs) are promising anticancer agents. Biodegradable nanoparticulate systems have received considerable attention as potential drug delivery vehicles. The aim of this study was to evaluate the effects of indomethacin-loaded nanocapsules and indomethacin ethyl ester-loaded nanocapsules on glioma cell lines. In addition, the effect of these formulations on normal neural tissue was also evaluated. In order to investigate this, glioma cell lines (U138-MG and C6) and hippocampal organotypic cultures were used. The main finding of the present study is that indomethacin-loaded nanocapsules formulation was more potent than a solution of indomethacin in decreasing the viability and cell proliferation of glioma lines. Indomethacin and indomethacin ethyl ester associated together in the same nanocapsule formulation caused a synergic effect decreasing glioma cell proliferation. In addition, when the glioma cells were exposed to 25 microM of indomethacin-loaded nanocapsules or indomethacin ethyl ester-loaded nanocapsules, a necrotic cell death was observed. Interestingly, 5 microM of indomethacin-loaded nanocapsules was able to cause an antiproliferative effect without promoting necrosis in glioma cells. Another important finding was that the cytotoxic effect induced by 25 microM or 50 microM of indomethacin-loaded nanocapsules or indomethacin ethyl ester-loaded nanocapsules, in glioma cells was not observed in the organotypic cultures, indicating selective cytotoxicity of those formulations for tumoral cells. Further investigations using in vivo glioma model should be helpful to confirm the distinct effects of indomethacin-loaded nanocapsules and indomethacin ethyl ester-loaded nanocapsules, in normal versus tumoral cells.
Asunto(s)
Antiinflamatorios no Esteroideos/toxicidad , Antineoplásicos , Neoplasias Encefálicas/tratamiento farmacológico , Inhibidores de la Ciclooxigenasa 2/toxicidad , Glioma/tratamiento farmacológico , Indometacina/análogos & derivados , Indometacina/toxicidad , Animales , Neoplasias Encefálicas/patología , Recuento de Células , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Fenómenos Químicos , Química Física , Colorantes , Composición de Medicamentos , Glioma/patología , Hipocampo/efectos de los fármacos , Humanos , Concentración de Iones de Hidrógeno , Masculino , Nanocápsulas , Técnicas de Cultivo de Órganos , Propidio , Ratas , Ratas Wistar , SuspensionesRESUMEN
Alzheimer's disease (AD), the most common form of dementia in late life, will become even more prevalent by midcentury, constituting a major global health concern with huge implications for individuals and society. Despite scientific breakthroughs during the past decades that have expanded our knowledge on the cellular and molecular bases of AD, therapies that effectively halt disease progression are still lacking, and focused efforts are needed to address this public health challenge. Because AD is classically recognized as a disease of memory, studies have mainly focused on investigating memory-associated brain defects. However, compelling evidence has indicated that additional brain regions, not classically linked to memory, are also affected in the course of disease. In this review, we outline the current understanding of key pathophysiological mechanisms in AD and their clinical manifestation. We also highlight how considering the complex nature of AD pathogenesis, and exploring repurposed drug approaches can pave the road toward the development of novel therapeutics for AD.
RESUMEN
Clinical trials have extensively failed to find effective treatments for Alzheimer's disease (AD) so far. Even after decades of AD research, there are still limited options for treating dementia. Mounting evidence has indicated that AD patients develop central and peripheral metabolic dysfunction, and the underpinnings of such events have recently begun to emerge. Basic and preclinical studies have unveiled key pathophysiological mechanisms that include aberrant brain stress signaling, inflammation, and impaired insulin sensitivity. These findings are in accordance with clinical and neuropathological data suggesting that AD patients undergo central and peripheral metabolic deregulation. Here, we review recent basic and clinical findings indicating that metabolic defects are central to AD pathophysiology. We further propose a view for future therapeutics that incorporates metabolic defects as a core feature of AD pathogenesis. This approach could improve disease understanding and therapy development through drug repurposing and/or identification of novel metabolic targets.
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Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/tratamiento farmacológico , Animales , HumanosRESUMEN
Lysosomal Storage Disorders (LSDs) are characterized by an abnormal accumulation of substrates within the lysosome and comprise more than 50 genetic disorders with a frequency of 1:5000 live births. Nanotechnology may be a promising way to circumvent the drawbacks of the current therapies for lysosomal diseases. The blood circulation time and bioavailability of the enzymes or drugs could be improved by inserting them in nanocarriers, which could decrease and/or avoid the need of frequent intravenous infusions along with the minimization or elimination of associated immunogenic responses. Considering the exposed, we aimed to build monoolein-based nanoparticles stabilized by polysorbate 80 as a smart platform able to reach the central nervous system (CNS) to deliver drugs or enzymes inside lysosomes. We developed and characterized the nanoparticles by dynamic light scattering (DLS), small-angle X-ray scattering (SAXS) and cryogenic transmission electron microscopy (Cryo-TEM). The nanoparticles showed a diameter of 115â¯nm, which is compatible with in vivo application. The SAXS patterns of the formulations displayed a single broad correlation peak that was fitted to the Teubner-Strey model confirming that disordered bicontinuous structures were obtained. Cryo-TEM images corroborated this finding and showed nanoparticles with size values that are similar to those determined by DLS. Furthermore, the nanoparticles did not present cytotoxicity when they were incubated with human fibroblasts, and demonstrated hemolytic activity proportional to the negative control, proving to be safe for parenteral administration. Through the use of a fluorescent dye to track the nanoparticles inside the cell, we demonstrated that they reached lysosomes after 1â¯h of treatment. More interestingly, the fluorescent dye was detected in the CNS of mice just after 3â¯h of treatment. The nanoparticles show great potential to improve the treatment of LSDs with brain impairment, acting as a smart platform to targeted delivery of drugs or enzymes.
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Sistema Nervioso Central/efectos de los fármacos , Glicéridos/química , Enfermedades por Almacenamiento Lisosomal/tratamiento farmacológico , Nanopartículas/química , Animales , Línea Celular , Sistemas de Liberación de Medicamentos/métodos , Humanos , Lisosomas/efectos de los fármacos , Masculino , Ratones , Nanotecnología/métodos , Dispersión del Ángulo Pequeño , Difracción de Rayos X/métodosRESUMEN
Sepsis survivors frequently develop late cognitive impairment. Because little is known on the mechanisms of post-septic memory deficits, there are no current effective approaches to prevent or treat such symptoms. Here, we subjected mice to severe sepsis induced by cecal ligation and puncture (CLP) and evaluated the sepsis-surviving animals in the open field, novel object recognition (NOR), and step-down inhibitory avoidance (IA) task at different times after surgery. Post-septic mice (30 days post-surgery) failed in the NOR and IA tests but exhibited normal performance when re-evaluated 45 days after surgery. Cognitive impairment in post-septic mice was accompanied by reduced hippocampal levels of proteins involved in synaptic plasticity, including synaptophysin, cAMP response element-binding protein (CREB), CREB phosphorylated at serine residue 133 (CREBpSer133), and GluA1 phosphorylated at serine residue 845 (GluA1pSer845). Expression of tumor necrosis factor α (TNF-α) was increased and brain insulin signaling was disrupted, as indicated by increased hippocampal IRS-1 phosphorylation at serine 636 (IRS-1pSer636) and decreased phosphorylation of IRS-1 at tyrosine 465 (IRS-1pTyr465), in the hippocampus 30 days after CLP. Phosphorylation of Akt at serine 473 (AktpSer473) and of GSK3 at serine 9 (GSK3ßpSer9) were also decreased in hippocampi of post-septic animals, further indicating that brain insulin signaling is disrupted by sepsis. We then treated post-septic mice with liraglutide, a GLP-1 receptor agonist with insulinotropic activity, or TDZD-8, a GSK3ß inhibitor, which rescued NOR memory. In conclusion, these results establish that hippocampal inflammation and disrupted insulin signaling are induced by sepsis and are linked to late memory impairment in sepsis survivors.
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Encéfalo/metabolismo , Disfunción Cognitiva/metabolismo , Insulina/metabolismo , Sepsis/metabolismo , Transducción de Señal/fisiología , Animales , Encéfalo/patología , Disfunción Cognitiva/etiología , Disfunción Cognitiva/patología , Conducta Exploratoria/fisiología , Masculino , Ratones , Sepsis/complicaciones , Sepsis/patologíaRESUMEN
In the present study we investigated the toxicity induced by exposing organotypic slice culture to beta-amyloid peptide 25-35 (25microM) for 1, 3, 6, 12, 24 and 48h. To elucidate a mechanism involved in its toxicity, we studied the PI3-K cell signaling pathway, particularly Akt/PKB, GSK-3beta, and PTEN proteins. Cell death was quantified by propidium iodide uptake and proteins were analyzed by immunoblotting. Our results showed a significant cell death after 48h of beta-amyloid 25-35 peptide exposition. The exposition of cultures to beta-amyloid peptide resulted in an increase in the phosphorylation state of Akt and GSK-3beta proteins after 6h, followed by a decrease of the phosphorylation state of these proteins after 12h of exposition. However, after 24h of peptide treatment, the phosphorylation of GSK-3beta presented a new increase while the phosphorylation of Akt remained down. The immunocontent of the PTEN protein, an indirect Akt phosphatase, increased after 24 and 48h of beta-amyloid exposition. These results suggest an involvement of Akt dephosphorylation/inactivation in the toxicity induced by the beta-amyloid 25-35 peptide in organotypic slice hippocampal culture, probably induced by increasing PTEN immunocontent. Taken together, our results provide more information about the molecular mechanisms involved on beta-amyloid peptide toxicity.
Asunto(s)
Péptidos beta-Amiloides/toxicidad , Glucógeno Sintasa Quinasa 3/metabolismo , Hipocampo/efectos de los fármacos , Fosfohidrolasa PTEN/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Animales , Western Blotting , Glucógeno Sintasa Quinasa 3 beta , Hipocampo/enzimología , Hipocampo/metabolismo , Técnicas In Vitro , Masculino , Fosforilación , RatasRESUMEN
Alzheimer's disease (AD) is associated with peripheral metabolic disorders. Clinical/epidemiological data indicate increased risk of diabetes in AD patients. Here, we show that intracerebroventricular infusion of AD-associated Aß oligomers (AßOs) in mice triggered peripheral glucose intolerance, a phenomenon further verified in two transgenic mouse models of AD. Systemically injected AßOs failed to induce glucose intolerance, suggesting AßOs target brain regions involved in peripheral metabolic control. Accordingly, we show that AßOs affected hypothalamic neurons in culture, inducing eukaryotic translation initiation factor 2α phosphorylation (eIF2α-P). AßOs further induced eIF2α-P and activated pro-inflammatory IKKß/NF-κB signaling in the hypothalamus of mice and macaques. AßOs failed to trigger peripheral glucose intolerance in tumor necrosis factor-α (TNF-α) receptor 1 knockout mice. Pharmacological inhibition of brain inflammation and endoplasmic reticulum stress prevented glucose intolerance in mice, indicating that AßOs act via a central route to affect peripheral glucose homeostasis. While the hypothalamus has been largely ignored in the AD field, our findings indicate that AßOs affect this brain region and reveal novel shared molecular mechanisms between hypothalamic dysfunction in metabolic disorders and AD.
Asunto(s)
Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Hipotálamo/metabolismo , Oligonucleótidos/metabolismo , Nervios Periféricos/metabolismo , Enfermedad de Alzheimer/genética , Péptidos beta-Amiloides/genética , Animales , Femenino , Glucosa/metabolismo , Humanos , Macaca , Masculino , Ratones , Ratones Endogámicos C57BL , FN-kappa B/genética , FN-kappa B/metabolismo , Neuronas/metabolismo , Oligonucleótidos/genética , Ratas , Transducción de Señal , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Berberine is an alkaloid derived from herb the Berberis sp. and has long-term use in Oriental medicine. Studies along the years have demonstrated its beneficial effect in various neurodegenerative and neuropsychiatric disorders. The subject of this study was to evaluate whether berberine protects against delayed neuronal cell death in organotypic hippocampal culture (OHC) exposed to oxygen and glucose deprivation (OGD) and the cell signaling mechanism related to its effect. Hippocampal slices were obtained from 6 to 8-days-old male Wistar rat and cultured for 14 days. Following, the cultures were exposed for 1h to OGD and then treated with Berberine (10 and 20µM). After 24h recovery, propidium iodide (PI) uptake was analyzed and a decrease was observed in PI uptake on OGD Ber-treated culture, which means a decrease in cellular death. Western blot analysis showed that proteins Akt, GSK3ß, ERK and JNK appear to play a role in berberine-mediated neuroprotection. Furthermore, capase-3 activity of OGD Ber-treated culture was diminished by control level in a fluorimetry assay. These findings suggest that berberine-mediated neuroprotection after ischemia involves Akt/GSK3ß/ERK 1/2 survival/apoptotic signaling pathway as well as JNK and caspase-3 activity inhibition.