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Dementia is a common feature of several age-related brain diseases, leading to a progressive cognitive decline. Due to a growing aging rate, dementia-related disorders currently affect around 50 million people worldwide and by 2050 this number is expected to reach 150 million. Additionally to patients, these neurodegenerative pathologies have a strong impact on family members, caretakers, and other health professionals, therefore representing a public health burden that in 2020 accounted for over 1 trillion USD and is projected to nearly double in the next decade. To overcome this devastating condition, many organizations and collaborative networks sustain that only a complete understanding of dementia in its different characteristics can drive the scientific community towards the development of effective therapeutic approaches aiming at preventing its onset and halting its progression.In this work, we discuss two topics that represent fundamental resources in fighting dementia: (i) the importance of raising awareness about this condition to avoid stigma and gauging investment; and (ii) the introduction of novel screening measures to prevent and potentially revert cognitive decline. Finally, we discern how knowledge-based advocacy will help the rollout of clinical trials and the development of novel and timely pharmacological interventions.
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BACKGROUND: Nursing students represent an important resource both for the patients and for the company organization; however, the impact of their presence on the quality of care is still underestimated. OBJECTIVE: To provide an objective assessment of the quality of care perceived by the patient admitted to hospital departments where internships are held for nursing students. METHOD: A descriptive observational study was conducted, recruiting a convenience sample made up of patients hospitalized in clinical departments where internships for nursing students of La Fe Hospital in Valencia (ES) are located. RESULTS: 75 patients out of 160 hospitalized partecipated to the survey, with a response rate equal to 46.87%. Most patients believe that nurses have careless attitudes towards them (42.9%) even though there is a noticeable emotional support from nurses perceived by patients (90.1%). The degree of relationship and information perceived by patients (96%) suggests that nurses in most cases guaranteed confidentiality and the assistance time employed (70.5%) was perceived as longer than usual, defining a high opinion of patients about the treatment received. CONCLUSIONS: The data showed that patients were very keen to be taken into consideration from a social and human point of view and not only from a clinical point of view, so much so that they claimed to perceive a careless attitude from nurses. Despite this, however, the perceived quality of nursing care by the patient was not affected. Regarding the presence of the trainee student, being the latter in the Spanish reality totally flanked by that of the nurse, almost in symbiosis, the degree of attention perceived by the patient in relation to the assistance provided does not vary.
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Internato e Residência , Cuidados de Enfermagem , Estudantes de Enfermagem , Atitude do Pessoal de Saúde , Humanos , Inquéritos e QuestionáriosRESUMO
Olfaction is in addition to touch the most ancient of our senses, developing already in the womb it decays progressively from 65 years of age with a more pronounced impairment associated with dementia. Despite its clinical relevance and testing accessibility, smell remains an overlooked biomarker, which is rarely used by neurologists in the early screening phase. In this perspective article, we outline the reasons underlying the lack of awareness for this sense. In an attempt to put olfaction forward as an early biomarker for pathological brain aging, we draw a comparison with vision and hearing, regarded as more relevant for general health. This perspective article wants to encourage further studies aimed at understanding the mechanisms responsible for the early smell dysfunction in individuals a decade or more before the onset of cognitive symptoms.
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BACKGROUND: The COVID-19 pandemic had a relevant health impact in a large part of the planet and there are several studies aimed at understanding its diffusion; however, to date, the problem has not been explored in the correctional setting, with particular concern for the Italian context. AIM: To assess and investigate the risk of exposure to COVID-19 in nurses working in the Italian prison system. METHODS: A multicenter observational descriptive study was conducted, enrolling a convenience sample composed of nurses registered with SIMSPE onlus (Italian Society of Penitentiary Medicine and Health), working in any Italian prison facility at the time of the survey. RESULTS: 204 nurses participating in the survey (response rate 49.27%). Most nurses working in prisons (92.65%) were exposed to the risk of Covid-19 virus infection, since they came directly into contact with positive patients (90.69%) and in situations where they were exposed during care procedures in which aerosol was produced by the patient (56.21%). The number of nurses who "always" complied with safety rules for prevention of infection did not differ significantly (p >0.05 for each comparison) in situations involving or not involving aerosol exposure. CONCLUSIONS: The results highlight the relevance of these issues in the Italian prison context and the need for further investigation. The knowledge of the dimension of this phenomenon, unexplored before this study in this context, represents the first step to be able to identify organizational strategies to manage it effectively or, if possible, to prevent it.
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COVID-19/epidemiologia , COVID-19/prevenção & controle , Pessoal de Saúde , Exposição Ocupacional/prevenção & controle , Prisões , Adulto , Idoso , Feminino , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Medição de Risco , Gestão de RiscosRESUMO
Sensory capacities like smell, taste, hearing, vision decline with aging, but increasing evidence show that sensory dysfunctions are one of the early signs diagnosing the conversion from physiological to pathological brain state. Smell loss represents the best characterized sense in clinical practice and is considered as one of the first preclinical signs of Alzheimer's and Parkinson's disease, occurring a decade or more before the onset of cognitive and motor symptoms. Despite the numerous scientific reports and the adoption in clinical practice, the etiology of sensory damage as prodromal of dementia remains largely unexplored and more studies are needed to resolve the mechanisms underlying sensory network dysfunction. Although both cognitive and sensory domains are progressively affected, loss of sensory experience in early stages plays a major role in reducing the autonomy of demented people in their daily tasks or even possibly contributing to their cognitive decline. Interestingly, the chemosensory circuitry is devoid of a blood brain barrier, representing a vulnerable port of entry for neurotoxic species that can spread to the brain. Furthermore, the exposure of the olfactory system to the external environment make it more susceptible to mechanical injury and trauma, which can cause degenerative neuroinflammation. In this review, we will summarize several findings about chemosensory impairment signing the conversion from healthy to pathological brain aging and we will try to connect those observations to the promising research linking environmental influences to sporadic dementia. The scientific body of knowledge will support the use of chemosensory diagnostics in the presymptomatic stages of AD and other biomarkers with the scope of finding treatment strategies before the onset of the disease.
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Demência/fisiopatologia , Transtornos do Olfato/diagnóstico , Olfato , Envelhecimento , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/fisiopatologia , Biomarcadores , Disfunção Cognitiva/diagnóstico , Demência/diagnóstico , Humanos , Inflamação , Doença de Parkinson/diagnóstico , Doença de Parkinson/fisiopatologiaRESUMO
White matter hyperintensities (WMHs) are frequently seen on brain magnetic resonance imaging scans of older people. Usually interpreted clinically as a surrogate for cerebral small vessel disease, WMHs are associated with increased likelihood of cognitive impairment and dementia (including Alzheimer's disease [AD]). WMHs are also seen in cognitively healthy people. In this collaboration of academic, clinical, and pharmaceutical industry perspectives, we identify outstanding questions about WMHs and their relation to cognition, dementia, and AD. What molecular and cellular changes underlie WMHs? What are the neuropathological correlates of WMHs? To what extent are demyelination and inflammation present? Is it helpful to subdivide into periventricular and subcortical WMHs? What do WMHs signify in people diagnosed with AD? What are the risk factors for developing WMHs? What preventive and therapeutic strategies target WMHs? Answering these questions will improve prevention and treatment of WMHs and dementia.
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Olfaction declines with aging and appears to be a prodromal sign of cognitive decline in progressive neurodegenerative diseases. Nevertheless, very little is known about the pathophysiological changes underlying smell loss that may reflect early network dysfunction. A cross-sectional histoanatomical study was conducted on postmortem olfactory nerves of patients with increasing severity of dementia from mild cognitive impairment (MCI) to moderate and severe Alzheimer's disease. The olfactory bulbs and tracts show a prominent and progressive tauopathy in contrast to a weaker amyloid pathology localized to the glomerular region. Topological analysis of Notch signaling components reveals a transient increase in Jagged1 expression in mitral cells of the olfactory bulb of patients with MCI and a gradual decline onwards. Analysis of the olfactory tract reveals an abundance of corpora amylacea, which declines starting from the MCI stage. With the increasing severity of dementia, corpora amylacea are characterized by a gradual shift in cytoskeletal proteins, tau, MAP2 and glial fibrillary acid protein, as well as by a decrease in their Reelin and Jagged1 content. Our research indicates that the olfactory nerve undergoes early and sequential morphological and signaling alterations that correlate with the development of dementia suggesting that this structure may capture and propagate neuronal network imbalances to connected higher brain centers of the entorhinal cortex and hippocampus.
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Doença de Alzheimer/patologia , Bulbo Olfatório/patologia , Transdução de Sinais/fisiologia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/metabolismo , Doença de Alzheimer/fisiopatologia , Moléculas de Adesão Celular Neuronais/genética , Moléculas de Adesão Celular Neuronais/metabolismo , Estudos Transversais , Progressão da Doença , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/metabolismo , Feminino , Expressão Gênica , Humanos , Proteína Jagged-1/metabolismo , Masculino , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Bulbo Olfatório/metabolismo , Bulbo Olfatório/fisiopatologia , Proteína Reelina , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Proteínas tau/genética , Proteínas tau/metabolismoRESUMO
The basal forebrain has received much attention due to its involvement in multiple cognitive functions, but little is known about the basic neuronal mechanisms underlying its development, nor those mediating its primary role in Alzheimer’s disease. We have previously suggested that a novel 14-mer peptide, ‘T14’, could play a pivotal role in Alzheimer’s disease, via reactivation of a developmental signaling pathway. In this study, we have characterized T14 in the context of post-natal rat brain development, using a combination of different techniques. Ex-vivo rat brain slices containing the basal forebrain, at different stages of development, were used to investigate large-scale neuronal network activity in real time with voltage-sensitive dye imaging. Subsequent Western blot analysis revealed the expression profile of endogenous T14, its target alpha7 nicotinic receptor and the familiar markers of Alzheimer’s: amyloid beta and phosphorylated Tau. Results indicated maximal neuronal activity at the earliest ages during development, reflected in a concomitant profile of T14 peptide levels and related proteins. In conclusion, these findings show that the peptide, already implicated in neurodegenerative events, has an age-dependent expression, suggesting a possible contribution to the physiological mechanisms underlying brain maturation.
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Despite many studies attempt to identify the primary mechanisms underlying neurodegeneration in Alzheimer's disease (AD), the key events still remain elusive. We have previously shown that a peptide cleaved from the acetylcholinesterase (AChE) C-terminus (T14) can play a pivotal role as a signaling molecule in neurodegeneration, via its interaction with the α7 nicotinic acetylcholine receptor. The main goal of this study is to determine whether a cyclized variant (NBP14) of the toxic AChE-derived peptide can antagonize the effects of its linear counterpart, T14, in modulating well-known markers linked to neurodegeneration. We investigate this hypothesis applying NBP14 on ex-vivo rat brain slices containing the basal forebrain. Western blot analysis revealed an inhibitory action of NBP14 on naturally occurring T14 peptide, as well as on endogenous amyloid beta, whereas the expression of the nicotinic receptor and phosphorylated Tau was relatively unaffected. These results further confirm the neurotoxic properties of the AChE-peptide and show for the first time in an ex-vivo preparation the possible neuroprotective activity of NBP14, over a protracted period of hours, indicating that T14 pathway may offer a new prospect for therapeutic intervention in AD pathobiology.
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Despite numerous studies that attempt to develop reliable animal models which reflecting the primary processes underlying neurodegeneration, very few have been widely accepted. Here, we propose a new procedure adapted from the well-known ex vivo brain slice technique, which offers a closer in vivo-like scenario than in vitro preparations, for investigating the early events triggering cell degeneration, as observed in Alzheimer's disease (AD). This variation consists of simple and easily reproducible steps, which enable preservation of the anatomical cytoarchitecture of the selected brain region and its local functionality in a physiological milieu. Different anatomical areas can be obtained from the same brain, providing the opportunity to perform multiple experiments with the treatments in question in a site-, dose-, and time-dependent manner. Potential limitations which could affect the outcomes related to this methodology are related to the conservation of the tissue, i.e., the maintenance of its anatomical integrity during the slicing and incubation steps and the section thickness, which can influence the biochemical and immunohistochemical analysis. This approach can be employed for different purposes, such as exploring molecular mechanisms involved in physiological or pathological conditions, drug screening, or dose-response assays. Finally, this protocol could also reduce the number of animals employed in behavioral studies. The application reported here has been recently described and tested for the first time on ex vivo rat brain slices containing the basal forebrain (BF), which is one of the cerebral regions primarily affected in AD. Specifically, it has been demonstrated that the administration of a toxic peptide derived from the C-terminus of acetylcholinesterase (AChE) could prompt an AD-like profile, triggering, along the antero-posterior axis of the BF, a differential expression of proteins altered in AD, such as the alpha7 nicotinic receptor (α7-nAChR), phosphorylated Tau (p-Tau), and amyloid beta (Aß).
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Encéfalo/fisiopatologia , Doenças Neurodegenerativas/fisiopatologia , Técnicas de Cultura de Tecidos/métodos , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Doença de Alzheimer/fisiopatologia , Peptídeos beta-Amiloides/metabolismo , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/cirurgia , Masculino , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia , RatosRESUMO
Currently there is no widely accepted animal model reproducing the full pathological profile of Alzheimer's disease (AD), since the basic mechanisms of neurodegeneration are still poorly understood. We have proposed that the interaction between the α7 nicotinic acetylcholine receptor (α7-nAChR) and a recently discovered toxic peptide, cleaved from the acetylcholinesterase (AChE) C-terminus, could account for the aberrant processes occurring in AD. In this article we describe a new application on ex vivo model procedure, which combines the advantages of both in vivo and in vitro preparations, to study the effects of the AChE-derived peptide on the rat basal forebrain (BF). Western blot analysis showed that the levels of α7-nAChR, p-Tau and Aß are differentially expressed upon the AChE-peptide administration, in a selective site-dependent manner. In conclusion, this methodology demonstrates the action of a novel peptide in triggering an AD-like phenotype and proposes a new ex vivo approach for manipulating and monitoring neurochemical processes contributing to neurodegeneration, in a time-dependent and site-specific manner.
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BACKGROUND: Notch1 signaling is a cellular cascade with a fundamental role from brain development to adult brain function. Reduction in Notch1 affects synaptic plasticity, memory and olfaction. On the other hand, Notch1 overactivation after brain injury is detrimental for neuronal survival. Some familial Alzheimer's disease (FAD) mutations in Presenilins can affect Notch1 processing/activation. Others report that Notch1 is overexpressed in sporadic Alzheimer's disease (AD). These works indicate that imbalances in Notch1 may be implicated in AD pathophysiology. In this study, we addressed whether Notch1 alteration can be considered a hallmark of AD. RESULTS: Immunohistochemical analysis of Notch1 on cortical and hippocampal tissue from post-mortem patients indicates an accumulation of Notch1 in plaque-like structures in the brain parenchyma of subjects with sporadic AD. Further analysis shows that displaced Notch1 is associated with fibrillary tangles/plaques. Biochemical validation confirms an accumulation of Notch1 in cytosolic brain fractions. This increase in protein is not accompanied with a raise in the Notch1 targets Hes1 and Hey1. Examination of the cerebrospinal fluid (CSF) indicates that the full length and truncations of the Notch1 protein are reduced in AD patients hinting at an accumulation in the brain parenchyma. CONCLUSIONS: Our research indicates that Notch1 is significantly displaced and accumulated in fibrillary structures in the susceptible hippocampal and cortical regions of sporadic AD patients. The dominant deposition of Notch1 in the brain parenchyma and its general signal reduction in neurons is consistent in all the AD patients analyzed and suggests that Notch1 may potentially be considered a novel hallmark of AD.
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Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Receptor Notch1/metabolismo , Idoso , Idoso de 80 Anos ou mais , Animais , Benzotiazóis , Biomarcadores/líquido cefalorraquidiano , Western Blotting , Linhagem Celular Tumoral , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Modelos Animais de Doenças , Feminino , Hipocampo/metabolismo , Hipocampo/patologia , Humanos , Imuno-Histoquímica , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Pessoa de Meia-Idade , Placa Amiloide/metabolismo , Placa Amiloide/patologia , Tiazóis/metabolismo , Proteínas tau/metabolismoRESUMO
UNLABELLED: Notch signaling plays a crucial role in adult brain function such as synaptic plasticity, memory and olfaction. Several reports suggest an involvement of this pathway in neurodegenerative dementia. Yet, to date, the mechanism underlying Notch activity in mature neurons remains unresolved. In this work, we investigate how Notch regulates synaptic potentiation and contributes to the establishment of memory in mice. We observe that Notch1 is a postsynaptic receptor with functional interactions with the Reelin receptor, apolipoprotein E receptor 2 (ApoER2) and the ionotropic receptor, N-methyl-D-aspartate receptor (NMDAR). Targeted loss of Notch1 in the hippocampal CA fields affects Reelin signaling by influencing Dab1 expression and impairs the synaptic potentiation achieved through Reelin stimulation. Further analysis indicates that loss of Notch1 affects the expression and composition of the NMDAR but not AMPAR. Glutamatergic signaling is further compromised through downregulation of CamKII and its secondary and tertiary messengers resulting in reduced cAMP response element-binding (CREB) signaling. Our results identify Notch1 as an important regulator of mechanisms involved in synaptic plasticity and memory formation. These findings emphasize the possible involvement of this signaling receptor in dementia. HIGHLIGHTS: In this paper, we propose a mechanism for Notch1-dependent plasticity that likely underlies the function of Notch1 in memory formation: Notch1 interacts with another important developmental pathway, the Reelin cascade.Notch1 regulates both NMDAR expression and composition.Notch1 influences a cascade of cellular events culminating in CREB activation.
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Genomic studies suggest an association of circadian clock genes with bipolar disorder (BD) and lithium response in humans. Therefore, we tested mice mutant in various clock genes before and after lithium treatment in the forced swim test (FST), a rodent behavioral test used for evaluation of depressive-like states. We find that expression of circadian clock components, including Per2, Cry1 and Rev-erbα, is affected by lithium treatment, and thus, these clock components may contribute to the beneficial effects of lithium therapy. In particular, we observed that Cry1 is important at specific times of the day to transmit lithium-mediated effects. Interestingly, the pathways involving Per2 and Cry1, which regulate the behavior in the FST and the response to lithium, are distinct as evidenced by the phosphorylation of GSK3ß after lithium treatment and the modulation of dopamine levels in the striatum. Furthermore, we observed the co-existence of depressive and mania-like symptoms in Cry1 knock-out mice, which resembles the so-called mixed state seen in BD patients. Taken together our results strengthen the concept that a defective circadian timing system may impact directly or indirectly on mood-related behaviors.
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Comportamento Animal/efeitos dos fármacos , Relógios Circadianos/genética , Ritmo Circadiano/efeitos dos fármacos , Ritmo Circadiano/genética , Lítio/farmacologia , Animais , Comportamento Animal/fisiologia , Transtorno Bipolar/genética , Proteínas CLOCK/genética , Depressão/genética , Modelos Animais de Doenças , Dopamina/metabolismo , Camundongos Knockout , Camundongos TransgênicosRESUMO
Olfaction is highly conserved among species and is required for reproduction and survival. In humans, olfaction is also one of the senses that is affected with aging and is a strong predictor of neurodegenerative diseases. Thus, olfaction testing is used as a non-invasive diagnostic method to detect neurological deficits early on. In order to understand the mechanisms underlying olfactory network susceptibility, olfactory research in rodents has gained momentum in the past decade. Here, we present a very simple, time efficient and reproducible olfactory testing method of innate odor perception and sensitivity in mice without the need of any prior food or water restriction. The tests are performed in a familiar environment to the mice, require only the scents and a 2 min session of odorant exposure. The analysis is performed, post-hoc, using computer-assisted commands on ImageJ and can be, therefore, carried out from start to end by one researcher. This protocol does not require any special hardware or setup and is indicated for any laboratory interested in testing olfactory perception and sensitivity.
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Comportamento Animal/fisiologia , Percepção Olfatória/fisiologia , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Odorantes , Gravação em Vídeo/métodosRESUMO
Notch signalling plays an important role in synaptic plasticity, learning and memory functions in both Drosophila and rodents. In this paper, we report that this feature is not restricted to hippocampal networks but also involves the olfactory bulb (OB). Odour discrimination and olfactory learning in rodents are essential for survival. Notch1 expression is enriched in mitral cells of the mouse OB. These principal neurons are responsive to specific input odorants and relay the signal to the olfactory cortex. Olfactory stimulation activates a subset of mitral cells, which show an increase in Notch activity. In Notch1cKOKln mice, the loss of Notch1 in mitral cells affects the magnitude of the neuronal response to olfactory stimuli. In addition, Notch1cKOKln mice display reduced olfactory aversion to propionic acid as compared to wildtype controls. This indicates, for the first time, that Notch1 is involved in olfactory processing and may contribute to olfactory behaviour.
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Aprendizagem da Esquiva/fisiologia , Neurônios Aferentes/fisiologia , Odorantes , Bulbo Olfatório/fisiologia , Percepção Olfatória/fisiologia , Receptor Notch1/metabolismo , Olfato/fisiologia , Animais , Proteínas de Ligação ao Cálcio/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Proteínas de Drosophila , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteína Jagged-1 , Masculino , Proteínas de Membrana/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurônios Aferentes/efeitos dos fármacos , Bulbo Olfatório/efeitos dos fármacos , Pentanóis/farmacologia , Proteínas Proto-Oncogênicas c-fos/metabolismo , Fármacos do Sistema Sensorial/farmacologia , Proteínas Serrate-Jagged , Olfato/efeitos dos fármacosRESUMO
The function of the nuclear receptor Rev-erbα (Nr1d1) in the brain is, apart from its role in the circadian clock mechanism, unknown. Therefore, we compared gene expression profiles in the brain between wild-type and Rev-erbα knock-out (KO) animals. We identified fatty acid binding protein 7 (Fabp7, Blbp) as a direct target of repression by REV-ERBα. Loss of Rev-erbα manifested in memory and mood related behavioral phenotypes and led to overexpression of Fabp7 in various brain areas including the subgranular zone (SGZ) of the hippocampus, where neuronal progenitor cells (NPCs) can initiate adult neurogenesis. We found increased proliferation of hippocampal neurons and loss of its diurnal pattern in Rev-erbα KO mice. In vitro, proliferation and migration of glioblastoma cells were affected by manipulating either Fabp7 expression or REV-ERBα activity. These results suggest an important role of Rev-erbα and Fabp7 in adult neurogenesis, which may open new avenues for treatment of gliomas as well as neurological diseases such as depression and Alzheimer.
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Envelhecimento/metabolismo , Proteínas de Transporte/genética , Hipocampo/crescimento & desenvolvimento , Hipocampo/metabolismo , Neurogênese , Membro 1 do Grupo D da Subfamília 1 de Receptores Nucleares/metabolismo , Proteínas Supressoras de Tumor/genética , Afeto/fisiologia , Animais , Comportamento Animal , Proteínas de Transporte/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Ritmo Circadiano , Cognição , Giro Denteado/metabolismo , Proteína 7 de Ligação a Ácidos Graxos , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Genoma , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Imuno-Histoquímica , Camundongos Knockout , Membro 1 do Grupo D da Subfamília 1 de Receptores Nucleares/deficiência , Regiões Promotoras Genéticas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Proteínas Supressoras de Tumor/metabolismoRESUMO
Notch signaling is an evolutionarily conserved pathway, which is fundamental for neuronal development and specification. In the last decade, increasing evidence has pointed out an important role of this pathway beyond embryonic development, indicating that Notch also displays a critical function in the mature brain of vertebrates and invertebrates. This pathway appears to be involved in neural progenitor regulation, neuronal connectivity, synaptic plasticity and learning/memory. In addition, Notch appears to be aberrantly regulated in neurodegenerative diseases, including Alzheimer's disease and ischemic injury. The molecular mechanisms by which Notch displays these functions in the mature brain are not fully understood, but are currently the subject of intense research. In this review, we will discuss old and novel Notch targets and molecular mediators that contribute to Notch function in the mature brain and will summarize recent findings that explore the two facets of Notch signaling in brain physiology and pathology.