RESUMO
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.
RESUMO
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.
Assuntos
Neoplasias Encefálicas , Progressão da Doença , Glioblastoma , Doenças Neuroinflamatórias , Microambiente Tumoral , Humanos , Glioblastoma/patologia , Glioblastoma/imunologia , Glioblastoma/tratamento farmacológico , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/metabolismo , Doenças Neuroinflamatórias/patologia , Doenças Neuroinflamatórias/imunologia , Astrócitos/patologia , Astrócitos/metabolismo , Astrócitos/imunologia , Animais , Macrófagos Associados a Tumor/imunologia , Macrófagos Associados a Tumor/metabolismo , Macrófagos Associados a Tumor/patologia , Transdução de Sinais , Microglia/patologia , Microglia/imunologiaRESUMO
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.
Assuntos
Encéfalo/fisiologia , Comunicação Celular/fisiologia , Ácidos Graxos Voláteis/fisiologia , Microbioma Gastrointestinal/fisiologia , Intestinos/fisiologia , Animais , HumanosRESUMO
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.
Assuntos
Colesterol/metabolismo , Nanopartículas/administração & dosagem , Doença de Niemann-Pick Tipo C/tratamento farmacológico , beta-Ciclodextrinas/administração & dosagem , Animais , Transporte Biológico , Estudos de Casos e Controles , Criança , Feminino , Fibroblastos/efeitos dos fármacos , Humanos , Lisossomos/metabolismo , Masculino , Camundongos , Doença de Niemann-Pick Tipo C/metabolismo , beta-Ciclodextrinas/farmacologiaRESUMO
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.
Assuntos
Doença de Alzheimer/metabolismo , Doença de Alzheimer/fisiopatologia , Fibronectinas/metabolismo , Transtornos da Memória/complicações , Transtornos da Memória/fisiopatologia , Plasticidade Neuronal , Condicionamento Físico Animal , Adolescente , Adulto , Idoso , Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/genética , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Modelos Animais de Doenças , Regulação para Baixo , Feminino , Fibronectinas/líquido cefalorraquidiano , Fibronectinas/genética , Humanos , Potenciação de Longa Duração , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêutico , Transdução de SinaisRESUMO
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.
Assuntos
Sistema Nervoso Central/efeitos dos fármacos , Glicerídeos/química , Doenças por Armazenamento dos Lisossomos/tratamento farmacológico , Nanopartículas/química , Animais , Linhagem Celular , Sistemas de Liberação de Medicamentos/métodos , Humanos , Lisossomos/efeitos dos fármacos , Masculino , Camundongos , Nanotecnologia/métodos , Espalhamento a Baixo Ângulo , Difração de Raios X/métodosRESUMO
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.
Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/farmacocinética , Estilbenos/administração & dosagem , Estilbenos/farmacocinética , Animais , Doenças Cardiovasculares/dietoterapia , Doenças Cardiovasculares/tratamento farmacológico , Ensaios Clínicos como Assunto , Humanos , Inflamação/dietoterapia , Inflamação/tratamento farmacológico , Camundongos , Neoplasias/dietoterapia , Neoplasias/tratamento farmacológico , Obesidade/dietoterapia , Obesidade/tratamento farmacológico , Ratos , Doenças Respiratórias/dietoterapia , Doenças Respiratórias/tratamento farmacológico , ResveratrolRESUMO
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.
Assuntos
Doença de Alzheimer/metabolismo , Doença de Alzheimer/tratamento farmacológico , Animais , HumanosRESUMO
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.
RESUMO
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.
Assuntos
Encéfalo/metabolismo , Disfunção Cognitiva/metabolismo , Insulina/metabolismo , Sepse/metabolismo , Transdução de Sinais/fisiologia , Animais , Encéfalo/patologia , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/patologia , Comportamento Exploratório/fisiologia , Masculino , Camundongos , Sepse/complicações , Sepse/patologiaRESUMO
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.
Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Hipotálamo/metabolismo , Oligonucleotídeos/metabolismo , Nervos Periféricos/metabolismo , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/genética , Animais , Feminino , Glucose/metabolismo , Humanos , Macaca , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/genética , NF-kappa B/metabolismo , Neurônios/metabolismo , Oligonucleotídeos/genética , Ratos , Transdução de Sinais , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Alzheimer's disease (AD) and type 2 diabetes appear to share similar pathogenic mechanisms. dsRNA-dependent protein kinase (PKR) underlies peripheral insulin resistance in metabolic disorders. PKR phosphorylates eukaryotic translation initiation factor 2α (eIF2α-P), and AD brains exhibit elevated phospho-PKR and eIF2α-P levels. Whether and how PKR and eIF2α-P participate in defective brain insulin signaling and cognitive impairment in AD are unknown. We report that ß-amyloid oligomers, AD-associated toxins, activate PKR in a tumor necrosis factor α (TNF-α)-dependent manner, resulting in eIF2α-P, neuronal insulin receptor substrate (IRS-1) inhibition, synapse loss, and memory impairment. Brain phospho-PKR and eIF2α-P were elevated in AD animal models, including monkeys given intracerebroventricular oligomer infusions. Oligomers failed to trigger eIF2α-P and cognitive impairment in PKR(-/-) and TNFR1(-/-) mice. Bolstering insulin signaling rescued phospho-PKR and eIF2α-P. Results reveal pathogenic mechanisms shared by AD and diabetes and establish that proinflammatory signaling mediates oligomer-induced IRS-1 inhibition and PKR-dependent synapse and memory loss.
Assuntos
Peptídeos beta-Amiloides/toxicidade , Encéfalo/efeitos dos fármacos , Proteínas Substratos do Receptor de Insulina/metabolismo , Polímeros/toxicidade , Fator de Necrose Tumoral alfa/metabolismo , eIF-2 Quinase/metabolismo , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/química , Animais , Encéfalo/metabolismo , Modelos Animais de Doenças , Haplorrinos/metabolismo , Hipoglicemiantes/farmacologia , Proteínas Substratos do Receptor de Insulina/antagonistas & inibidores , Transtornos da Memória/metabolismo , Transtornos da Memória/patologia , Camundongos , Camundongos Knockout , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fosforilação/efeitos dos fármacos , Polímeros/química , Receptores Tipo I de Fatores de Necrose Tumoral/deficiência , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sinapses/efeitos dos fármacos , Sinapses/metabolismo , Fator de Necrose Tumoral alfa/antagonistas & inibidores , eIF-2 Quinase/deficiência , eIF-2 Quinase/genéticaRESUMO
Resveratrol, a natural polyphenolic compound, has attracted considerable interest for its anti-inflammatory and neuroprotective properties. However, the biological effects of resveratrol appear strongly limited because it is photosensitive, easily oxidized, and has unfavorable pharmacokinetics. The present study aimed to elucidate the effect of resveratrol on Abeta-triggered neuroinflammation by comparing the effects of free resveratrol (RSV) treatment with those of treatment with resveratrol-loaded lipid-core nanocapsules (RSV-LNC). Organotypic hippocampal cultures were stimulated by Abeta1-42 with or without different concentrations of RSV or RSV-LNC. We found that Abeta triggered a harmful neuroinflammation process in organotypic hippocampal cultures. Pre- and co-treatments with RSV-LNC were able to protect cultures against ROS formation and cell death induced by Abeta, possibly through sustained blocking of TNF-alpha, IL-1beta, and IL-6 release. Furthermore, RSV-LNC was able to increase IL-10 release even in the presence of Abeta and prevent or decrease both glial and JNK activation. On the other hand, both pre- and co-treatment with RSV exhibited a lower ability to prevent or decrease neuroinflammation, ROS formation, and cell death, and failed to increase IL-10 release. Our findings suggest that modulation of neuroinflammation through a combination of resveratrol and a lipid-core nanocapsule-based delivery system might represent a promising approach for preventing or delaying the neurodegenerative process triggered by Abeta. The results open new vistas to the interplay between inflammation and amyloid pathology.
Assuntos
Anti-Inflamatórios/farmacologia , Inflamação/prevenção & controle , Lipídeos/farmacologia , Nanocápsulas/química , Neurônios/efeitos dos fármacos , Estilbenos/farmacologia , Peptídeos beta-Amiloides , Animais , Anti-Inflamatórios/administração & dosagem , Células Cultivadas , Sinergismo Farmacológico , Encefalite/induzido quimicamente , Encefalite/patologia , Encefalite/prevenção & controle , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipocampo/patologia , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/patologia , Lipídeos/administração & dosagem , Lipídeos/química , Masculino , Neurônios/patologia , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Resveratrol , Estilbenos/administração & dosagemRESUMO
BACKGROUND/AIM: Despite recent progress in glioblastoma treatment, prognosis is still poor. Monastrol is a kinesin spindle protein (KSP) inhibitor and anticancer effects for this molecule have been reported. Here we describe the effect of LaSOM 65, a monastrol derivated compound, against glioma cell lines. MATERIALS AND METHODS: Cell counting, viability assay, lactate dehydrogenase (LDH) activity, cell-cycle analysis, immunofluorescence and organotypic hippocampal slice cultures were performed. RESULTS: LaSOM 65 reduced cell number and cell viability of gliomas cells, but did not cause arrest in the cell cycle at the G2/M phase. Measurement of LDH activity showed that LaSOM 65 induces necrosis after 48 h of treatment. CONCLUSION: LaSOM 65 appears to a be promising new molecule to treat glioblastoma since it promotes a decrease of cell growth and cell viability of glioma cells in vitro and does not induces the neurotoxic characteristics of the anti-mitotic drugs currently used.
Assuntos
Antineoplásicos/farmacologia , Pirimidinas/farmacologia , Tionas/farmacologia , Animais , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Núcleo Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Glioblastoma , Hipocampo/efeitos dos fármacos , Humanos , L-Lactato Desidrogenase/metabolismo , Necrose , Ratos , Técnicas de Cultura de Tecidos , Tubulina (Proteína)/metabolismoRESUMO
OBJECTIVE: Accumulating evidence indicates that curcumin potently protects against beta-amyloid (Abeta) due to its oxygen free radicals scavenging and anti-inflammatory properties. However, cellular mechanisms that may underlie the neuroprotective effect of curcumin in Abeta-induced toxicity are not fully understood yet. The present study was undertaken to investigate the mechanisms involved in neuroprotective effects of curcumin, particularly involving Wnt/beta-catenin and PI3K pathways. METHODS: Organotypic hippocampal slice cultures were treated with curcumin and exposed to Abeta1-42 for 48 hours. Synaptic dysfunction, cell death, ROS formation, neuroinflammation and beta-catenin, Akt, and GSK-3beta phosphorylation were measured to determine the effects of curcumin against Abeta toxicity. RESULTS: Curcumin significantly attenuated Abeta-induced cell death, loss of synaptophysin, and ROS generation. Furthermore, curcumin was able to decrease IL-6 release and increase IL-10 release, and prevented glial activation. The phosphorylation of beta-catenin was avoided and the levels of free beta-catenin were increased by curcumin to promote cell survival upon treatment with Abeta. Curcumin, in the presence of Abeta, activated Akt which in turn phosphorylates GSK-3beta, and resulted in the inhibition of GSK-3beta. The presence of LY294002, an inhibitor of PI3K pathway, blocked the pro-survival effect of curcumin. DISCUSSION: These results reinforce the neuroprotective effects of curcumin on Abeta toxicity and add some evidence that its mechanism may involve beta-catenin and PI3K signaling pathway in organotypic hippocampal slice culture.
Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Curcumina/farmacologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Fragmentos de Peptídeos/antagonistas & inibidores , Fosfatidilinositol 3-Quinases/metabolismo , beta Catenina/metabolismo , Peptídeos beta-Amiloides/toxicidade , Animais , Morte Celular/efeitos dos fármacos , Cromonas/farmacologia , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Interleucina-10/metabolismo , Interleucina-6/metabolismo , Masculino , Morfolinas/farmacologia , Fármacos Neuroprotetores/farmacologia , Fragmentos de Peptídeos/toxicidade , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos , Sinaptofisina/metabolismoRESUMO
The development of novel therapeutic strategies to treat gliomas remains critical as a result of the poor prognoses, inef-. ficient therapies and recurrence associated with these tumors. In this context, biodegradable nanoparticles are emerging as efficient drug delivery systems for the treatment of difficult-to-treat diseases such as brain tumors. In the current study, we evaluated the antiglioma effect of trans-resveratrol-loaded lipid-core nanocapsules (RSV-LNC) based on in vitro (C6 glioma cell line) and in vivo (brain-implanted C6 cells) models of the disease. In vitro, RSV-LNC decreased the viability of C6 glioma cells to a higher extent than resveratrol in solution. Interestingly, RSV-LNC treatment was not cytotoxic to hippocampal organotypic cultures, a model of healthy neural cells, suggesting selectivity for cancer cells. RSV-LNC induced losses in glioma cell viability through induction of apoptotic cell death, as assessed by Annexin-FITC/PI assay, which was preceded by an early arrest in the S and G1 phases of the cell cycle. In brain-implanted C6 tumors, treatment with RSV-LNC (5 mg/kg/day, i.p.) for 10 days promoted a marked decrease in tumor size and also reduced the incidence of some malignant tumor-associated characteristics, such as intratumoral hemorrhaging, intratumoral edema and pseudopalisading, compared to resveratrol in solution. Taken together, the results presented herein suggest that nanoencapsulation of resveratrol improves its antiglioma activity, thus providing a provocative foundation for testing the clinical usefulness of nanoformulations of this natural compound as a new chemotherapeutic strategy for the treatment of gliomas.
Assuntos
Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Glioma/tratamento farmacológico , Glioma/patologia , Lipídeos/química , Nanocápsulas/química , Estilbenos/uso terapêutico , Animais , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Fenômenos Químicos , Química Farmacêutica , Modelos Animais de Doenças , Fase G1/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Humanos , Masculino , Transplante de Neoplasias , Ratos , Ratos Wistar , Resveratrol , Fase S/efeitos dos fármacos , Soluções , Estilbenos/farmacologia , Carga Tumoral/efeitos dos fármacosRESUMO
Despite recent advances in radiotherapy, chemotherapy, and surgical techniques, glioblastoma multiforme (GBM) prognosis remains dismal. There is an urgent need for new therapeutic strategies. Nanoparticles of biodegradable polymers for anticancer drug delivery have attracted intense interest in recent years because they can provide sustained, controlled, and targeted delivery. Here, we investigate the mechanisms involved in the antiproliferative effect of indomethacin-loaded lipid-core nanocapsules (IndOH-LNC) in glioma cells. IndOH-LNC were able to reduce cell viability by inducing apoptotic cell death in C6 and U138-MG glioma cell lines. Interestingly, IndOH-LNC did not affect the viability of primary astrocytes, suggesting that this formulation selectively targeted transformed cells. Mechanistically, IndOH-LNC induced inhibition of cell growth and cell-cycle arrest to be correlated with the inactivation of AKT and ß-catenin and the activation of GSK-3ß. IndOH-LNC also induced G0/G1 and/or G2/M phase arrest, which was accompanied by a decrease in the levels of cyclin D1, cyclin B1, pRb, and pcdc2 and an increase in the levels of Wee1 CDK inhibitor p21(WAF1). Additionally, IndOH-LNC promoted GBM cell differentiation, observed as upregulation of glial fibrillary acidic protein (GFAP) protein and downregulation of nestin and CD133. Taken together, the crosstalk among antiproliferative effects, cell-cycle arrest, apoptosis, and cell differentiation should be considered when tailoring pharmacological interventions aimed at reducing glioma growth by using formulations with multiples targets, such as IndOH-LNC.
Assuntos
Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/tratamento farmacológico , Indometacina/administração & dosagem , Nanocápsulas/administração & dosagem , Análise de Variância , Animais , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Glioblastoma/metabolismo , Glioblastoma/patologia , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Humanos , Indometacina/química , Nanocápsulas/química , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Transdução de Sinais/efeitos dos fármacos , beta Catenina/metabolismoRESUMO
Alzheimer's disease (AD), a neurodegenerative disorder exhibiting a gradual decline in cognitive function, is characterized by the presence of neuritic plaques composed of neurofibrillary tangles and amyloid-ß (Aß) peptide. Available drugs for AD therapy have small effect sizes and do not alter disease progression. Several studies have been shown that resveratrol is associated with anti-amyloidogenic properties, but therapeutic application of its beneficial effects is limited. Here we compared the neuroprotective effects of free resveratrol treatment with those of resveratrol-loaded lipid-core nanocapsule treatment against intracerebroventricular injection of Aß1-42 in rats. Animals received a single intracerebroventricular injection of Aß1-42 (2 nmol), and 1 day after Aß infusion, they were administered either free resveratrol (RSV) or resveratrol-loaded lipid-core nanocapsules (5 mg/kg, each 12 h, intraperitoneally), for 14 days. Aß1-42-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 c-Jun N-terminal kinase (JNK) and glycogen synthase kinase-3ß (GSK-3ß) activation, beyond destabilization of ß-catenin levels. Our results clearly show that by using lipid-core nanocapsules, resveratrol was able to rescue the deleterious effects of Aß1-42 while treatment with RSV presented only partial beneficial effects. These findings might be explained by the robust increase of resveratrol concentration in the brain tissue achieved by lipid-core nanocapsules. Our data not only confirm the potential of resveratrol in treating AD but also offer an effective way to improve the efficiency of resveratrol through the use of nanodrug delivery systems.
Assuntos
Peptídeos beta-Amiloides/administração & dosagem , Lipídeos/química , Nanocápsulas/química , Fármacos Neuroprotetores/farmacologia , Estilbenos/farmacologia , Peptídeos beta-Amiloides/toxicidade , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Astrócitos/patologia , Citoproteção/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Hipocampo/efeitos dos fármacos , Hipocampo/enzimologia , Hipocampo/patologia , Injeções Intraventriculares , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Masculino , Transtornos da Memória/tratamento farmacológico , Microglia/efeitos dos fármacos , Microglia/metabolismo , Microglia/patologia , Fármacos Neuroprotetores/uso terapêutico , Estabilidade Proteica/efeitos dos fármacos , Ratos , Ratos Wistar , Resveratrol , Transdução de Sinais/efeitos dos fármacos , Estilbenos/efeitos adversos , Estilbenos/uso terapêutico , Sinapses/efeitos dos fármacos , Sinapses/patologia , Distribuição Tecidual/efeitos dos fármacos , beta Catenina/metabolismoRESUMO
Neuroinflammation, characterized by the accumulation of activated microglia and reactive astrocytes, is believed to modulate the development and/or progression of Alzheimer's disease (AD). Epidemiological studies suggesting that nonsteroidal anti-inflammatory drugs decrease the risk of developing AD have encouraged further studies elucidating the role of inflammation in AD. Nanoparticles have become an important focus of neurotherapeutic research because they are an especially effective form of drug delivery. Here, we investigate the potential protective effect of indomethacin-loaded lipid-core nanocapsules (IndOH-LNCs) against cell damage and neuroinflammation induced by amyloid beta (Aß)1-42 in AD models. Our results show that IndOH-LNCs attenuated Aß-induced cell death and were able to block the neuroinflammation triggered by Aß1-42 in organotypic hippocampal cultures. Additionally, IndOH-LNC treatment was able to increase interleukin-10 release and decrease glial activation and c-jun N-terminal kinase phosphorylation. As a model of Aß-induced neurotoxicity in vivo, animals received a single intracerebroventricular injection of Aß1-42 (1 nmol/site), and 1 day after Aß1-42 infusion, they were administered either free IndOH or IndOH-LNCs (1 mg/kg, intraperitoneally) for 14 days. Only the treatment with IndOH-LNCs significantly attenuated the impairment of this behavior triggered by intracerebroventricular injection of Aß1-42. Further, treatment with IndOH-LNCs was able to block the decreased synaptophysin levels induced by Aß1-42 and suppress glial and microglial activation. These findings might be explained by the increase of IndOH concentration in brain tissue attained using drug-loaded lipid-core NCs. All these findings support the idea that blockage of neuroinflammation triggered by Aß is involved in the neuroprotective effects of IndOH-LNCs. These data provide strong evidence that IndOH-LNC treatment may represent a promising approach for treating AD.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides , Modelos Animais de Doenças , Indometacina/administração & dosagem , Lipídeos/química , Nanocápsulas/administração & dosagem , Fragmentos de Peptídeos , Doença de Alzheimer/induzido quimicamente , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Humanos , Indometacina/química , Masculino , Nanocápsulas/química , Ratos Wistar , Resultado do TratamentoRESUMO
The effect of Aß25-35 peptide, in its fibrillar and non-fibrillar forms, on ganglioside expression in organotypic hippocampal slice cultures was investigated. Gangliosides were endogenously labeled with D-[1-C(14)] galactose and results showed that Aß25-35 affected ganglioside expression, depending on the peptide aggregation state, that is, fibrillar Aß25-35 caused an increase in GM3 labeling and a reduction in GD1b labeling, whereas the non-fibrillar form was able to enhance GM1 expression. Interestingly, GM1 exhibited a neuroprotective effect in this organotypic model, since pre-treatment of the hippocampal slices with GM1 10 µM was able to prevent the toxicity triggered by the fibrillar Aß25-35, when measured by propidium iodide uptake protocol. With the purpose of further investigating a possible mechanism of action, we analyzed the effect of GM1 treatment (1, 6, 12 and 24h) upon the Aß-induced alterations on GSK3ß dephosphorylation/activation state. Results demonstrated an important effect after 24-h incubation, with GM1 preventing the Aß-induced dephosphorylation (activation) of GSK3ß, a signaling pathway involved in apoptosis triggering and neuronal death in models of Alzheimer's disease. Taken together, present results provide a new and important support for ganglioside participation in development of Alzheimer's disease experimental models and suggest a protective role for GM1 in Aß-induced toxicity. This may be useful for designing new therapeutic strategies for Alzheimer's treatment.