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The accumulation of soluble oligomers of the amyloid-ß peptide (AßOs) in the brain has been implicated in synapse failure and memory impairment in Alzheimer's disease. Here, we initially show that treatment with NUsc1, a single-chain variable-fragment antibody (scFv) that selectively targets a subpopulation of AßOs and shows minimal reactivity to Aß monomers and fibrils, prevents the inhibition of long-term potentiation in hippocampal slices and memory impairment induced by AßOs in mice. As a therapeutic approach for intracerebral antibody delivery, we developed an adeno-associated virus vector to drive neuronal expression of NUsc1 (AAV-NUsc1) within the brain. Transduction by AAV-NUsc1 induced NUsc1 expression and secretion in adult human brain slices and inhibited AßO binding to neurons and AßO-induced loss of dendritic spines in primary rat hippocampal cultures. Treatment of mice with AAV-NUsc1 prevented memory impairment induced by AßOs and, remarkably, reversed memory deficits in aged APPswe/PS1ΔE9 Alzheimer's disease model mice. These results support the feasibility of immunotherapy using viral vector-mediated gene delivery of NUsc1 or other AßO-specific single-chain antibodies as a potential therapeutic approach in Alzheimer's disease.
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Doença de Alzheimer , Anticorpos de Cadeia Única , Camundongos , Ratos , Humanos , Animais , Idoso , Doença de Alzheimer/genética , Doença de Alzheimer/terapia , Doença de Alzheimer/metabolismo , Anticorpos de Cadeia Única/genética , Anticorpos de Cadeia Única/metabolismo , Peptídeos beta-Amiloides/genética , Peptídeos beta-Amiloides/metabolismo , Sinapses/metabolismo , Neurônios/metabolismo , Transtornos da Memória/genética , Transtornos da Memória/terapiaRESUMO
BACKGROUND: The GABAergic system plays an important role in modulating levels of anxiety. When transplanted into the brain, precursor cells from the medial ganglionic eminence (MGE) have the ability to differentiate into GABAergic interneurons and modify the inhibitory tone in the host brain. Currently, two methods have been reported for obtaining MGE precursor cells for transplantation: fresh and neurosphere dissociated cells. Here, we investigated the effects generated by transplantation of the two types of cell preparations on anxiety behavior in rats. RESULTS: We transplanted freshly dissociated or neurosphere dissociated cells into the neonate brain of male rats on postnatal (PN) day 2-3. At early adulthood (PN 62-63), transplanted animals were tested in the Elevated Plus Maze (EPM). To verify the differentiation and migration pattern of the transplanted cells in vitro and in vivo, we performed immunohistochemistry for GFP and several interneuron-specific markers: neuropeptide Y (NPY), parvalbumin (PV) and calretinin (CR). Cells from both types of preparations expressed these interneuronal markers. However, an anxiolytic effect on behavior in the EPM was observed in animals that received the MGE-derived freshly dissociated cells but not in those that received the neurosphere dissociated cells. CONCLUSION: Our results suggest a long-lasting anxiolytic effect of transplanted freshly dissociated cells that reinforces the inhibitory function of the GABAergic neuronal circuitry in the hippocampus related to anxiety-like behavior in rats.
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Ansiedade/terapia , Transplante de Células/métodos , Células-Tronco Embrionárias/transplante , Eminência Mediana/transplante , Células-Tronco Neurais/transplante , Animais , Animais Recém-Nascidos , Ansiedade/fisiopatologia , Calbindina 2/metabolismo , Técnicas de Cultura de Células , Movimento Celular/fisiologia , Córtex Cerebral/fisiopatologia , Células-Tronco Embrionárias/fisiologia , Comportamento Exploratório/fisiologia , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Hipocampo/fisiopatologia , Interneurônios/fisiologia , Masculino , Eminência Mediana/embriologia , Eminência Mediana/fisiologia , Células-Tronco Neurais/fisiologia , Neurogênese/fisiologia , Neuropeptídeo Y/metabolismo , Parvalbuminas/metabolismo , Ratos Sprague-Dawley , Ratos TransgênicosRESUMO
BACKGROUND: Neural progenitor cells (NPCs) can be cultivated from developing brains, reproducing many of the processes that occur during neural development. They can be isolated from a variety of animal models, such as transgenic mice carrying mutations in amyloid precursor protein (APP) and presenilin 1 and 2 (PSEN 1 and 2), characteristic of familial Alzheimer's disease (fAD). Modulating the development of these cells with inflammation-related peptides, such as bradykinin (BK) and its antagonist HOE-140, enables the understanding of the impact of such molecules in a relevant AD model. RESULTS: We performed a global gene expression analysis on transgenic neurospheres treated with BK and HOE-140. To validate the microarray data, quantitative real-time reverse-transcription polymerase chain reaction (RT-PCR) was performed on 8 important genes related to the immune response in AD such as CCL12, CCL5, CCL3, C3, CX3CR1, TLR2 and TNF alpha and Iba-1. Furthermore, comparative analysis of the transcriptional profiles was performed between treatments, including gene ontology and reactome enrichment, construction and analysis of protein-protein interaction networks and, finally, comparison of our data with human dataset from AD patients. The treatments affected the expression levels of genes mainly related to microglia-mediated neuroinflammatory responses, with BK promoting an increase in the expression of genes that enrich processes, biological pathways, and cellular components related to immune dysfunction, neurodegeneration and cell cycle. B2 receptor inhibition by HOE-140 resulted in the reduction of AD-related anomalies caused in this system. CONCLUSIONS: BK is an important immunomodulatory agent and enhances the immunological changes identified in transgenic neurospheres carrying the genetic load of AD. Bradykinin treatments modulate the expression rates of genes related to microglia-mediated neuroinflammation. Inhibiting bradykinin activity in Alzheimer's disease may slow disease progression.
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BACKGROUND: Bone marrow is an accessible source of progenitor cells, which have been investigated as treatment for neurological diseases in a number of clinical trials. Here we evaluated the potential benefit of bone marrow cells in protecting against convulsive seizures induced by maximum electroconvulsive shock (MES), a widely used model for screening of anti-epileptic drugs. Behavioral and inflammatory responses were measured after MES induction in order to verify the effects promoted by transplantation of bone marrow cells. To assess the anticonvulsant effects of bone marrow cell transplantation, we measured the frequency and duration of tonic seizure, the mortality rate, the microglial expression and the blood levels of cytokine IL-1, IL-6, IL-10 and TNF-α after MES induction. We hypothesized that these behavioral and inflammatory responses to a strong stimulus such as a convulsive seizure could be modified by the transplantation of bone marrow cells. RESULTS: Bone marrow transplanted cells altered the convulsive threshold and showed anticonvulsant effect by protecting from tonic seizures. Bone marrow cells modified the microglial expression in the analyzed brain areas, increased the IL-10 and attenuate IL-6 levels. CONCLUSIONS: Bone marrow cells exert protective effects by blocking the course of electroconvulsive seizures. Additionally, electroconvulsive seizures induced acute inflammatory responses by altering the pattern of microglia expression, as well as in IL-6 and IL-10 levels. Our findings also indicated that the anticonvulsant effects of these cells can be tested with the MES model following the same paradigm used for drug testing in pharmacological screening. Studies on the inflammatory reaction in response to acute seizures in the presence of transplanted bone marrow cells might open a wide range of discussions on the mechanisms relevant to the pathophysiology of epilepsies.
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Transplante de Medula Óssea/métodos , Encéfalo/citologia , Microglia/citologia , Convulsões/terapia , Animais , Citocinas/sangue , Eletrochoque/efeitos adversos , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BLRESUMO
With the increasing prevalence of Alzheimer's disease (AD) and difficulties in finding effective treatments, it is essential to discover alternative therapies through new approaches. In this regard, non-pharmacological therapies, such as physical exercise, have been proposed and explored for the treatment of AD. Recent studies have suggested that resistance exercise (RE) is an effective strategy for promoting benefits in memory and cognitive function, producing neuroprotective and anti-inflammatory effects, and reducing amyloid load and plaques, thereby reducing the risk, and alleviating the neurodegeneration process of AD and other types of dementia in the elderly. In addition, RE is the exercise recommended by the World Health Organization for the elderly due to its benefits in improving muscle strength and balance, and increasing autonomy and functional capacity, favoring improvements in the quality of life of the elderly population, who is more likely to develop AD and other types of dementia. In this mini-review, we discuss the impact of RE on humans affected by MCI and AD, and animal models of AD, and summarize the main findings regarding the effects of RE program on memory and cognitive functions, neurotrophic factors, Aß deposition and plaque formation, as well as on neuroinflammation. Overall, the present review provides clinical and preclinical evidence that RE plays a role in alleviating AD symptoms and may help to understand the therapeutic potential of RE, thereby continuing the advances in AD therapies.
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Proteins involved in the Alzheimer's disease (AD), such as amyloid precursor protein (APP) and presenilin-1 (PS1), play critical roles in early development of the central nervous system (CNS), as well as in innate immune and glial cell responses. Familial AD is associated with the presence of APPswe and PS1dE9 mutations. However, it is still unknown whether these mutations cause deficits in CNS development of carriers. We studied genome-wide gene expression profiles of differentiated neural progenitor cells (NPCs) from wild-type and APPswe/PS1dE9 mouse embryo telencephalon. The occurrence of strong innate immune and glial cell responses in APPswe/PS1dE9 neurospheres mainly involves microglial activation, inflammatory mediators and chemokines. APPswe/PS1dE9 neurospheres augmented up to 100-fold CCL12, CCL5, CCL3, C3, CX3CR1, TLR2 and TNF-alpha expression levels, when compared to WT neurospheres. Expression levels of the glia cell marker GFAP and microglia marker Iba-1 were up to 20-fold upregulated in APPswe/PS1dE9 neurospheres. The secretome of differentiated APPswe/PS1dE9 NPCs revealed enhanced chemoattraction of peripheral blood mononuclear cells. When evaluating the inferred protein interaction networks constructed from the array data, an improvement in astrocyte differentiation in APPswe/PS1dE9 neurospheres was evident in view of increased GFAP expression. Transgenic NPCs differentiated into neural phenotypes presented expression patterns of cytokine, glial cells, and inflammatory mediators characteristic of APPswe/PS1dE9 adult animals. Consequently, the neurogenic niche obtained from differentiation of embryonic APPswe/PS1dE9 neurospheres spontaneously presents several alterations observed in adult AD brains. Finally, our data strengthen pathophysiological hypotheses that propose an early neurodevelopmental origin for familial AD.
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Doença de Alzheimer , Camundongos , Animais , Doença de Alzheimer/genética , Doença de Alzheimer/complicações , Doença de Alzheimer/metabolismo , Leucócitos Mononucleares/metabolismo , Camundongos Transgênicos , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Neuroglia/metabolismo , Diferenciação Celular/genética , Mediadores da Inflamação , Imunidade Inata/genéticaRESUMO
About 10 million new cases of dementia develop worldwide each year, of which up to 70% are attributable to Alzheimer's disease (AD). In addition to the widely known symptoms of memory loss and cognitive impairment, AD patients frequently develop non-cognitive symptoms, referred to as behavioral and psychological symptoms of dementia (BPSDs). Sleep disorders are often associated with AD, but mood alterations, notably depression and apathy, comprise the most frequent class of BPSDs. BPSDs negatively affect the lives of AD patients and their caregivers, and have a significant impact on public health systems and the economy. Because treatments currently available for AD are not disease-modifying and mainly aim to ameliorate some of the cognitive symptoms, elucidating the mechanisms underlying mood alterations and other BPSDs in AD may reveal novel avenues for progress in AD therapy. Purinergic signaling is implicated in the pathophysiology of several central nervous system (CNS) disorders, such as AD, depression and sleep disorders. Here, we review recent findings indicating that purinergic receptors, mainly the A1, A2A, and P2X7 subtypes, are associated with the development/progression of AD. Current evidence suggests that targeting purinergic signaling may represent a promising therapeutic approach in AD and related conditions. This article is part of the Special Issue on "Purinergic Signaling: 50 years".
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Doença de Alzheimer , Disfunção Cognitiva , Transtornos do Sono-Vigília , Humanos , Doença de Alzheimer/psicologia , Testes Neuropsicológicos , Sintomas Comportamentais/etiologia , Transtornos do Sono-Vigília/etiologiaRESUMO
Alzheimer's disease (AD) is a severe disabling condition with no cure currently available, which accounts for 60-70% of all dementia cases worldwide. Therefore, the investigation of possible therapeutic strategies for AD is necessary. To this end, animal models corresponding to the main aspects of AD in humans have been widely used. Similar to AD patients, the double transgenic APPswe/PS1dE9 (APP/PS1) mice show cognitive deficits, hyperlocomotion, amyloid-ß (Αß) plaques in the cortex and hippocampus, and exacerbated inflammatory responses. Recent studies have shown that these neuropathological features could be reversed by stem cell transplantation. However, the effects induced by neural (NSC) and mesenchymal (MSC) stem cells has never been compared in an AD animal model. Therefore, the present study aimed to investigate whether transplantation of NSC or MSC into the hippocampus of APP/PS1 mice reverses AD-induced pathological alterations, evaluated by the locomotor activity (open field test), short- and long-term memory (object recognition) tests, Αß plaques (6-E10), microglia distribution (Iba-1), M1 (iNOS) and M2 (ARG-1) microglial phenotype frequencies. NSC and MSC engraftment reduced the number of Αß plaques and produced an increase in M2 microglia polarization in the hippocampus of APP/PS1 mice, suggesting an anti-inflammatory effect of stem cell transplantation. NSC also reversed the hyperlocomotor activity and increased the number of microglia in the hippocampus of APP/PS1 mice. No impairment of short or long-term memory was observed in APP/PS1 mice. Overall, this study highlights the potential beneficial effects of transplanting NSC or MSC for AD treatment.
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Doença de Alzheimer , Células-Tronco Mesenquimais , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Doença de Alzheimer/terapia , Peptídeos beta-Amiloides/metabolismo , Animais , Hipocampo/metabolismo , Hipocampo/patologia , Humanos , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Transgênicos , Placa Amiloide/patologiaRESUMO
In the present study, we evaluate the effect of acute restraint stress (15 min) of male Wistar rats on social interaction measurements and c-Fos immunoreactivity (c-Fos-ir) expression, a marker of neuronal activity, in areas involved with the modulation of acute physical restraint in rats, i.e., the paraventricular nucleus of the hypothalamus (PVN), median raphe nucleus (MnR), medial prefrontal cortex (mPFC), cingulate prefrontal cortex (cPFC), nucleus accumbens (NaC), hippocampus (CA3), lateral septum (LS) and medial amygdala (MeA). We considered the hypothesis that restraint stress exposure could promote social withdrawal induced by the activation of the hypothalamic-pituitary-adrenocortical (HPA) axis, and increase c-Fos expression in these limbic forebrain areas investigated. In addition, we investigated whether pretreatment with the atypical antipsychotic clozapine (5 mg/kg; I.P.) could attenuate or block the effects of restraint on these responses. We found that restraint stress induced social withdrawal, and increased c-Fos-ir in these areas, demonstrating that a single 15 min session of physical restraint of rats effectively activated the HPA axis, representing an effective tool for the investigation of neuronal activity in brain regions sensitive to stress. Conversely, pretreatment with clozapine, prevented social withdrawal and reduced c-Fos expression. We suggest that treatment with clozapine exerted a preventive effect in the social interaction deficit, at least in part, by blocking the effect of restraint stress in brain regions that are known to regulate the HPA-axis, including the cerebral cortex, hippocampus, hypothalamus, septum and amygdala. Further experiments will be done to confirm this hypothesis.
Assuntos
Restrição FísicaRESUMO
Temporal lobe epilepsy is the most common form of intractable epilepsy in adults. More than 30% of individuals with epilepsy have persistent seizures and have drug-resistant epilepsy. Based on our previous findings, treatment with bone marrow mononuclear cells (BMMC) could interfere with early and chronic phase epilepsy in rats and in clinical settings. In this pilocarpine-induced epilepsy model, animals were randomly assigned to two groups: control (Con) and epileptic pre-treatment (Ep-pre-t). The latter had status epilepticus (SE) induced through pilocarpine intraperitoneal injection. Later, seizure frequency was assessed using a video-monitoring system. Ep-pre-t was further divided into epileptic treated with saline (Ep-Veh) and epileptic treated with BMMC (Ep-BMMC) after an intravenous treatment with BMMC was done on day 22 after SE. Analysis of neurobehavioral parameters revealed that Ep-BMMC had significantly lower frequency of spontaneous recurrent seizures (SRS) in comparison to Ep-pre-t and Ep-Veh groups. Hippocampus-dependent spatial and non-spatial learning and memory were markedly impaired in epileptic rats, a deficit that was robustly recovered by treatment with BMMC. Moreover, long-term potentiation-induced synaptic remodeling present in epileptic rats was restored by BMMC. In addition, BMMC was able to reduce abnormal mossy fiber sprouting in the dentate gyrus. Molecular analysis in hippocampal tissue revealed that BMMC treatment down-regulates the release of inflammatory cytokine tumor necrosis factor-α (TNF-α) and Allograft inflammatory factor-1 (AIF-1) as well as the Rho subfamily of small GTPases [Ras homolog gene family member A (RhoA) and Ras-related C3 botulinum toxin substrate 1 (Rac)]. Collectively, delayed BMMC treatment showed positive effects when intravenously infused into chronic epileptic rats.
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Transplante de Medula Óssea , Cognição , Encefalite/fisiopatologia , Epilepsia/fisiopatologia , Epilepsia/psicologia , Nucleotídeos de Guanina/antagonistas & inibidores , Recuperação de Função Fisiológica , Animais , Comportamento Animal , Transplante de Medula Óssea/métodos , Modelos Animais de Doenças , Epilepsia/terapia , Infusões Intravenosas , Potenciação de Longa Duração , Masculino , Ratos WistarRESUMO
Neuroinflammation has been shown to play a crucial role in the development of Alzheimer's disease (AD) and also has an association with amyloid-ß (Aß) plaques, a hallmark of this disease. Physical exercise has emerged as an alternative treatment for pathological impairment in AD. In light of this evidence, together with the fact that the hippocampus is one of the first structures to be affected in AD, we analyzed hippocampal changes in Aß load, inflammatory responses, and locomotor activity in transgenic APP/PS1 mouse model for AD submitted to a resistance exercise (RE) program. One month after the start of the RE program, the locomotor hyperactivity related to AD behavior was reduced and microglia recruitment was increased, which in turn may have contributed to the decrease in the volume of Aß plaques. In addition, the RE program restored the levels of IL-1α, IL-4, and IL-6 cytokines to control levels. Our study indicates that RE has beneficial effects on the locomotor behavior, amyloid burden, and inflammation of AD pathology and can therefore be used as a therapy to improve the clinical symptoms and neurophysiological alterations in AD. To the best of our knowledge, this is the first study to use a resistance exercise program in transgenic AD model.
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Doença de Alzheimer/patologia , Precursor de Proteína beta-Amiloide/genética , Amiloide/metabolismo , Inflamação/patologia , Condicionamento Físico Animal , Presenilina-1/genética , Treinamento Resistido , Doença de Alzheimer/genética , Animais , Carga Corporal (Radioterapia) , Citocinas/metabolismo , Genótipo , Hipocampo/patologia , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Microglia , Atividade MotoraRESUMO
CB1 receptor antagonists have been shown to prevent acute and long-term behavioral effects of cocaine. Here we evaluate the effectiveness of the CB1 receptor antagonist rimonabant to modify sensitized responses to cocaine. Mice were treated with saline or cocaine injections in a 15-day intermittent sensitization treatment and subsequently treated with either vehicle, 1 or 10mg/kg rimonabant in the drug-associated environment for 8 consecutive days. Animals were then challenged with saline and cocaine in the open-field apparatus on subsequent days to evaluate the expression of conditioned and sensitized effects to cocaine. c-Fos protein expression was evaluated in the nucleus accumbens (NAcc), ventral tegmental area (VTA), basolateral amygdala (BLA), medial prefrontal cortex (mPFC) and caudate-putamen (CPu) after the last (cocaine) challenge. Previous treatment with 10mg/kg rimonabant blocked the expression of conditioned hyperlocomotion and behavioral sensitization to cocaine, but not acute cocaine-induced hyperlocomotion. These behavioral effects were accompanied by significant changes in c-Fos expression in the brain reward system. Chronic cocaine sensitization blunted a subsequent acute cocaine-induced increase in c-Fos protein in the NAcc, effect that was reversed by previous treatment with rimonabant. Treatment with 10mg/kg rimonabant also attenuated the significant increase in c-Fos expression in the CPu, mPFC and BLA induced by previous chronic sensitization with cocaine. Our findings add to the evidence that drugs targeting CB1 receptors are good candidates for the treatment of cocaine abuse and provide further insights into the mechanisms underlying endocannabinoid signaling within the brain reward system in the context of cocaine abuse.
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Comportamento Animal/efeitos dos fármacos , Antagonistas de Receptores de Canabinoides/farmacologia , Cocaína/farmacologia , Piperidinas/farmacologia , Proteínas Proto-Oncogênicas c-fos/metabolismo , Pirazóis/farmacologia , Animais , Locomoção/efeitos dos fármacos , Masculino , Camundongos , RimonabantoRESUMO
Cycloheximide influences synaptic reorganization resulting from pilocarpine-induced status epilepticus (SE). To investigate the possible behavioral consequences of this effect, we subjected animals to pilocarpine-induced SE either in the absence (Pilo group) or presence of cycloheximide (Chx group). Animals were further divided regarding the occurrence of spontaneous recurrent seizures (SRS). Two months after SE induction animals were exposed to different behavioral tests. Age-matched naïve animals were used as controls. All epileptic groups showed a significantly diminished freezing time in contextual and tone fear conditioning, performed poorly in the Morris water maze and present less seconds in immobility position as compared to controls. Only Pilo animals explored more extensively the open arms of the elevated plus maze and showed increased in horizontal exploratory activity in the open field as compared to controls. With the exception of Pilo animals without recorded SRS, all other groups had extensive tissue shrinkage in central nucleus of the amygdala as compared to controls. Cycloheximide-treated animals differed from Pilo animals in the extent of hilar loss and supragranular mossy fiber sprouting as well as tissue shrinkage in the dorsal hippocampus. Despite the histological differences seen in the dorsal hippocampus between experimental groups, no differences were encountered in the cognitive tests used to evaluate dorsal hippocampal function. The encountered histological differences between Chx and Pilo animals, however, might underlie the different emotional responses between the two groups.
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Comportamento Animal/efeitos dos fármacos , Cicloeximida/farmacologia , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/psicologia , Agonistas Muscarínicos , Pilocarpina , Inibidores da Síntese de Proteínas/farmacologia , Estimulação Acústica , Animais , Ansiedade/psicologia , Contagem de Células , Condicionamento Psicológico/efeitos dos fármacos , Depressão/psicologia , Comportamento Exploratório/efeitos dos fármacos , Masculino , Memória de Curto Prazo/efeitos dos fármacos , Fibras Musgosas Hipocampais/fisiologia , Ratos , Ratos Wistar , Recidiva , Natação/psicologiaRESUMO
Magnetic resonance imaging (MRI) is an excellent non-invasive tool to investigate biological systems. The administration of the paramagnetic divalent ion manganese (Mn(2+)) enhances MRI contrast in vivo. Due to similarities between Mn(2+) and calcium (Ca(2+)), the premise of manganese-enhanced MRI (MEMRI) is that the former may enter neurons and other excitable cells through voltage-gated Ca(2+) channels. As such, MEMRI has been used to trace neuronal pathways, define morphological boundaries, and study connectivity in morphological and functional imaging studies. In this article, we provide a brief overview of MEMRI and discuss recently published data to illustrate the usefulness of this method, particularly in animal models.
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Glioblastoma (GBM) is an infiltrative tumor that is difficult to eradicate. Treating GBM with mesenchymal stem cells (MSCs) that have been modified with the HSV-Tk suicide gene has brought significant advances mainly because MSCs are chemoattracted to GBM and kill tumor cells via a bystander effect. To use this strategy, abundantly present adipose-tissue-derived mesenchymal stem cells (AT-MSCs) were evaluated for the treatment of GBM in mice. AT-MSCs were prepared using a mechanical protocol to avoid contamination with animal protein and transduced with HSV-Tk via a lentiviral vector. The U-87 glioblastoma cells cultured with AT-MSC-HSV-Tk died in the presence of 25 or 50 µM ganciclovir (GCV). U-87 glioblastoma cells injected into the brains of nude mice generated tumors larger than 3.5 mm2 after 4 weeks, but the injection of AT-MSC-HSV-Tk cells one week after the U-87 injection, combined with GCV treatment, drastically reduced tumors to smaller than 0.5 mm2. Immunohistochemical analysis of the tumors showed the presence of AT-MSC-HSV-Tk cells only within the tumor and its vicinity, but not in other areas of the brain, showing chemoattraction between them. The abundance of AT-MSCs and the easier to obtain them mechanically are strong advantages when compared to using MSCs from other tissues.
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Tecido Adiposo/metabolismo , Glioblastoma/metabolismo , Células-Tronco Mesenquimais/enzimologia , Simplexvirus/genética , Timidina Quinase/biossíntese , Transdução Genética , Proteínas Virais/biossíntese , Tecido Adiposo/patologia , Animais , Efeito Espectador/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Ganciclovir/farmacologia , Glioblastoma/patologia , Glioblastoma/terapia , Humanos , Células-Tronco Mesenquimais/patologia , Camundongos , Camundongos Nus , Simplexvirus/enzimologia , Timidina Quinase/genética , Proteínas Virais/genéticaRESUMO
PURPOSE: Diseases such as temporal lobe epilepsy, brain trauma and stroke can induce endothelial cell proliferation and angiogenesis in specific brain areas. During status epilepticus (SE), bone marrow-derived cells are able to infiltrate and proliferate, dramatically increasing at the site of injury. However, it is still unclear whether these cells directly participate in vascular changes induced by SE. METHOD: To investigate the possible role of bone marrow-derived cells in angiogenesis after seizures, we induced SE by pilocarpine injection in previously prepared chimeric mice. Mice were euthanized at 8h, 7d or 15d after SE onset. RESULTS: Our results indicated that SE modified hippocampal vascularization and induced angiogenesis. Further, bone marrow-derived GFP(+) cells penetrated through the parenchyma and participated in the formation of new vessels after SE. We detected bone marrow-derived cells closely associated with vessels in the hippocampus, increasing the density of blood vessels that had decreased immediately after pilocarpine-induced SE. CONCLUSION: We conclude that epileptic seizures directly affect vascularization in the hippocampus mediated by bone marrow-derived cells in a time-dependent manner.
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Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Pilocarpina/toxicidade , Estado Epiléptico/patologia , Animais , Células da Medula Óssea/citologia , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/patologia , Hipocampo/irrigação sanguínea , Camundongos Endogâmicos C57BL , Convulsões/induzido quimicamente , Convulsões/patologia , Estado Epiléptico/induzido quimicamente , Fatores de TempoRESUMO
Patients with schizophrenia exhibit deficits in an operational measure of sensorimotor gating: prepulse inhibition (PPI) of startle. PPI is the normal reduction in the startle response caused by a low intensity non-startling stimulus (prepulse) which is presented shortly before the startle stimulus (pulse). MK-801 is an NMDA receptor-antagonist known to produce hyperactivity, deficits in prepulse inhibition and social withdrawal, behaviors which correlate well with some of the positive, cognitive and negative symptoms of schizophrenia. The inferior colliculus (IC) is a critical part of the auditory pathway mediating acoustic PPI. The activation of the IC by the acoustic prepulse reduces startle magnitude. Thus, the purpose of the present study was to elucidate the role of glutamatergic transmission in the IC on the expression of acoustic PPI. For that we investigated whether NMDA receptor stimulation or blockade would affect this response. Unilateral microinjections of NMDA (30 nmol/0.5 µL) into the IC did not alter PPI while microinjections of MK-801 (30 nmol/0.5 µL) into this structure disrupted PPI. We also examined the ability of the atypical antipsychotic olanzapine (5.0mg/kg; i.p.) to reverse the disruption of pre-pulse inhibition produced by unilateral microinjections of MK-801 into the IC of rats. Pretreatment with olanzapine blocked MK-801-induced disruption of PPI. Altogether, these results suggest that glutamate-mediated mechanisms of the IC are involved in the expression of PPI in rodents and that this response is sensitive to atypical antipsychotic olanzapine.
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Antipsicóticos/farmacologia , Benzodiazepinas/farmacologia , Maleato de Dizocilpina/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Colículos Inferiores/efeitos dos fármacos , Filtro Sensorial/efeitos dos fármacos , Estimulação Acústica/métodos , Análise de Variância , Animais , Agonistas de Aminoácidos Excitatórios/farmacologia , Masculino , Microinjeções , N-Metilaspartato/farmacologia , Olanzapina , Psicoacústica , Ratos , Ratos Wistar , Reflexo de Sobressalto/efeitos dos fármacosRESUMO
Several reports have shown that the hippocampus plays an important role in different aspects of the emotional control. There is evidence that lesions in this structure cause behavioral disinhibition, with reduction of reactions expressing fear and anxiety. Thus, to portray the aptitude of cell therapy to abrogate injuries of hippocampal tissue, we examined the behavioral effects of bone marrow mononuclear cells (BMMCs) transplantation on C57BL/6 mice that had the hippocampus damaged by electrolytic lesion. For this purpose, mice received, seven days after bilateral electrolytic lesion in the dorsal hippocampus, culture medium or BMMCs expressing the enhanced green fluorescent protein (EGFP) transgene. One week after transplantation, animals were tested in the elevated plus-maze (EPM). On the whole, three assessment sessions in the EPM were carried out, with seven days separating each trial. Thirty-five days after the induction of injury, mice were sacrificed and their brains removed for immunohistochemistry. The behavioral evaluation showed that the hippocampal lesion caused disinhibition, an effect which was slightly lessened, from the second EPM test, in transplanted subjects. On the other hand, immunohistochemical data revealed an insignificant presence of EGFP(+) cells inside the brains of injured mice. In view of such scenario, we hypothesized that the subtle rehabilitation of the altered behavior might be a result from a paracrine effect from the transplanted cells. This might have been caused by the release of bioactive factors capable of boosting endogenous recuperative mechanisms for a partial regaining of the hippocampal functions.
Assuntos
Comportamento Animal/efeitos dos fármacos , Transplante de Medula Óssea , Lesões Encefálicas/terapia , Hipocampo/lesões , Aprendizagem em Labirinto/efeitos dos fármacos , Animais , Ansiedade/fisiopatologia , Comportamento Animal/fisiologia , Transplante de Medula Óssea/métodos , Masculino , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Magnetic resonance images are useful in the study of experimental models of temporal lobe epilepsy. The manganese-enhanced MRI (MEMRI) technique is of interest since it combines the effects caused by manganese on the increased contrast in activated cell populations, when competing with calcium in synaptic transmission. Thus, the purpose of this study was to investigate the temporal evolution of the contrast related to manganese in the acute phase of temporal lobe epilepsy induced by systemic pilocarpine and compare it to the expression of the c-Fos protein. During this phase, the intensity of the MEMRI signal was analyzed at three different time points (5, 15 or 30 minutes) after the onset of status epilepticus (SE). The group that was maintained in status epilepticus for 30 minutes showed a decrease in intensity of the signal in CA1 and the dentate gyrus (DG). There were no differences between the control group and the other groups treated with pilocarpine. The expression of the protein, c-Fos, in the same animals showed that even in the short-duration status epilepticus (5 minutes), there was already maximal cellular activation in subregions of the hippocampus (DG, CA1 and CA3). Under the experimental conditions tested, our data suggest that the MEMRI signal was not sensitive for the identification of detectable variations of cell activation in the acute phase of the pilocarpine model. Our findings are not consistent with the idea that manganese contrast reflects primarily alterations in cellular activity during SE when other signal-modifying elements can act.
Assuntos
Meios de Contraste , Epilepsia do Lobo Temporal/patologia , Manganês , Proteínas Proto-Oncogênicas c-fos/análise , Doença Aguda , Animais , Giro Denteado/patologia , Modelos Animais de Doenças , Epilepsia do Lobo Temporal/induzido quimicamente , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pilocarpina , Ratos , Ratos WistarRESUMO
Magnetic resonance images are useful in the study of experimental models of temporal lobe epilepsy. The manganese-enhanced MRI (MEMRI) technique is of interest since it combines the effects caused by manganese on the increased contrast in activated cell populations, when competing with calcium in synaptic transmission. Thus, the purpose of this study was to investigate the temporal evolution of the contrast related to manganese in the acute phase of temporal lobe epilepsy induced by systemic pilocarpine and compare it to the expression of the c-Fos protein. During this phase, the intensity of the MEMRI signal was analyzed at three different time points (5, 15 or 30 minutes) after the onset of status epilepticus (SE). The group that was maintained in status epilepticus for 30 minutes showed a decrease in intensity of the signal in CA1 and the dentate gyrus (DG). There were no differences between the control group and the other groups treated with pilocarpine. The expression of the protein, c-Fos, in the same animals showed that even in the short-duration status epilepticus (5 minutes), there was already maximal cellular activation in subregions of the hippocampus (DG, CA1 and CA3). Under the experimental conditions tested, our data suggest that the MEMRI signal was not sensitive for the identification of detectable variations of cell activation in the acute phase of the pilocarpine model. Our findings are not consistent with the idea that manganese contrast reflects primarily alterations in cellular activity during SE when other signal-modifying elements can act.
As imagens de ressonância magnética são úteis no estudo de modelos experimentais de epilepsia do lobo temporal. A técnica manganese-enhanced MRI (MEMRI) é de interesse por combinar os efeitos provocados pelo manganês no aumento do contraste de populações celulares ativadas, ao competir com o cálcio na transmissão sináptica. Assim, o propósito deste estudo foi investigar a evolução temporal do contraste provocado pelo manganês na fase aguda da epilepsia do lobo temporal induzida por pilocarpina sistêmica e compará-las à expressão da proteína c-Fos. Nessa fase, a intensidade do sinal MEMRI foi analisada em três diferentes pontos temporais (5, 15 ou 30 minutos) após o início do status epilepticus (SE). O grupo que foi mantido em status epilepticus por 30 minutos mostrou diminuição na intensidade de sinal no CA1 e giro denteado (GD). Não houve diferenças entre o Grupo Controle e os outros grupos tratados com pilocarpina. A expressão da proteína c-Fos, nos mesmos animais, mostrou que, mesmo no status epilepticus de curta duração (5 minutos) já há ativação celular máxima nas sub-regiões do hipocampo (GD, CA1 e CA3). Nas condições experimentais testadas, nossos dados sugerem que o sinal MEMRI não foi sensível para identificar variações detectáveis da ativação celular na fase aguda do modelo de pilocarpina. Nossos achados não são consistentes com a ideia que o contraste por manganês reflete primariamente alterações na atividade celular durante o SE quando outros elementos modificadores do sinal podem atuar.