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1.
Proc Natl Acad Sci U S A ; 120(32): e2301730120, 2023 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-37523544

RESUMO

The brain employs distinct circuitries to encode positive and negative valence stimuli, and dysfunctions of these neuronal circuits have a key role in the etiopathogenesis of many psychiatric disorders. The Dorsal Raphè Nucleus (DRN) is involved in various behaviors and drives the emotional response to rewarding and aversive experiences. Whether specific subpopulations of neurons within the DRN encode these behaviors with different valence is still unknown. Notably, microRNA expression in the mammalian brain is characterized by tissue and neuronal specificity, suggesting that it might play a role in cell and circuit functionality. However, this specificity has not been fully exploited. Here, we demonstrate that microRNA-34a (miR-34a) is selectively expressed in a subpopulation of GABAergic neurons of the ventrolateral DRN. Moreover, we report that acute exposure to both aversive (restraint stress) and rewarding (chocolate) stimuli reduces GABA release in the DRN, an effect prevented by the inactivation of DRN miR-34a or its genetic deletion in GABAergic neurons in aversive but not rewarding conditions. Finally, miR-34a inhibition selectively reduced passive coping with severe stressors. These data support a role of miR-34a in regulating GABAergic neurotransmitter activity and behavior in a context-dependent manner and suggest that microRNAs could represent a functional signature of specific neuronal subpopulations with valence-specific activity in the brain.


Assuntos
Núcleo Dorsal da Rafe , MicroRNAs , Humanos , Animais , Núcleo Dorsal da Rafe/metabolismo , Neurônios GABAérgicos/metabolismo , MicroRNAs/metabolismo , Mamíferos
2.
Neurobiol Dis ; 181: 106106, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37001613

RESUMO

Epilepsy is a comorbidity associated with Alzheimer's disease (AD), often starting many years earlier than memory decline. Investigating this association in the early pre-symptomatic stages of AD can unveil new mechanisms of the pathology as well as guide the use of antiepileptic drugs to prevent or delay hyperexcitability-related pathological effects of AD. We investigated the impact of repeated seizures on hippocampal memory and amyloid-ß (Aß) load in pre-symptomatic Tg2576 mice, a transgenic model of AD. Seizure induction caused memory deficits and an increase in oligomeric Aß42 and fibrillary species selectively in pre-symptomatic transgenic mice, and not in their wildtype littermates. Electrophysiological patch-clamp recordings in ex vivo CA1 pyramidal neurons and immunoblots were carried out to investigate the neuronal alterations associated with the behavioral outcomes of Tg2576 mice. CA1 pyramidal neurons exhibited increased intrinsic excitability and lower hyperpolarization-activated Ih current. CA1 also displayed lower expression of the hyperpolarization-activated cyclic nucleotide-gated HCN1 subunit, a protein already identified as downregulated in the AD human proteome. The antiepileptic drug lamotrigine restored electrophysiological alterations and prevented both memory deficits and the increase in extracellular Aß induced by seizures. Thus our study provides evidence of pre-symptomatic hippocampal neuronal alterations leading to hyperexcitability and associated with both higher susceptibility to seizures and to AD-specific seizure-induced memory impairment. Our findings also provide a basis for the use of the antiepileptic drug lamotrigine as a way to counteract acceleration of AD induced by seizures in the early phases of the pathology.


Assuntos
Doença de Alzheimer , Camundongos , Humanos , Animais , Doença de Alzheimer/complicações , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Anticonvulsivantes/farmacologia , Lamotrigina/efeitos adversos , Hipocampo/metabolismo , Peptídeos beta-Amiloides/metabolismo , Convulsões/patologia , Camundongos Transgênicos , Modelos Animais de Doenças , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/etiologia , Transtornos da Memória/prevenção & controle
3.
BMC Vet Res ; 16(1): 278, 2020 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-32771003

RESUMO

BACKGROUND: Data on gamma-delta (γδ) T lymphocytes in the peripheral blood of dogs are scant, related only to healthy pure breed dogs and limited to a restricted age range. The aim of the study was to investigate the modulation of the γδ T lymphocyte (TCRγδ+) subpopulation in peripheral blood of crossbreed healthy dogs according to five identified stages of life: Puppy, Junior, Adult, Mature, Senior and to determine its implication in aging. A rigorous method of recruitment was used to minimize the influence of internal or external pressure on the immune response. Twenty-three intact female and twenty-four intact male dogs were enrolled. Blood samples were collected and immunophenotyping of peripheral blood T lymphocytes and γδ T cell subpopulations was performed. RESULTS: The percentage of γδ T cells in peripheral blood lymphocytes was comparable with the value of 2.5% published by Faldyna and co-workers (2001), despite the percentage reported was investigated in less arranged age range groups and coming from four different dog pure breeds, whereas our data were recorded on wider age range groups and coming from crossbreed dogs. Therefore, the γδ T cell percentage (2.5%) is consistent and points out that such value is breed-independent. Statistical analysis highlighted differences in both percentage and absolute γδ T cells according to the stage of life. γδ T cells decreased significantly in the peripheral blood of elder dogs (Senior group) in comparison with previous stages of life (Puppy, Junior, and Adult groups). Differences in γδ T cells are significant and they are reported, for the first time, related to dog aging. CONCLUSIONS: The study confirms dogs to be among the animals with a low TCRγδ+ cell profile. A decrease of the TCRγδ+ subpopulation percentage was observed in elder dogs. TCRγδ+ cells of group S were different from those of groups P, J, and A. The differences are reported for the first time in dog aging. Identifying the stage of life when the decrease of γδ T lymphocytes starts can be useful for providing a rationale for drafting a wellness plan trial to support thymus immune functions and mitigate its functional exhaustion.


Assuntos
Envelhecimento , Cães/fisiologia , Receptores de Antígenos de Linfócitos T gama-delta , Subpopulações de Linfócitos T/imunologia , Animais , Cães/imunologia , Feminino , Imunofenotipagem/veterinária , Masculino , Subpopulações de Linfócitos T/citologia , Linfócitos T/citologia , Linfócitos T/imunologia
4.
J Pharmacol Exp Ther ; 367(3): 483-493, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30301736

RESUMO

The glucocorticoid-induced leucine zipper (GILZ) mediates anti-inflammatory effects of glucocorticoids. Acute kidney injury (AKI) mobilizes immune/inflammatory mechanisms, causing tissue injury, but the impact of GILZ in AKI is not known. Neutrophils play context-specific proinflammatory [type 1 neutrophil (N1)] and anti-inflammatory [type 2 neutrophil (N2)] functional roles. Also, regulatory T lymphocytes (Tregs) and regulatory T-17 (Treg17) cells exert counterinflammatory effects, including the suppression of effector T lymphocytes [e.g., T-helper (Th) 17 cells]. Thus, utilizing cell preparations of mice kidneys subjected to AKI or sham operation, we determined the effects of GILZ on T cells and neutrophil subtypes in the context of its renoprotective effect; these studies used the transactivator of transcription (TAT)-GILZ or the TAT peptide. AKI increased N1 and Th-17 cells but reduced N2, Tregs, and Treg17 cells in association with increased interleukin (IL)-17+ but reduced IL-10+ cells accompanied with the disruption of mitochondrial membrane potential (ψ m) and increased apoptosis/necrosis compared with sham kidneys. TAT-GILZ, compared with TAT, treatment reduced N1 and Th-17 cells but increased N2 and Tregs, without affecting Treg17 cells, in association with a reduction in IL-17+ cells but an increase in IL-10+ cells; TAT-GILZ caused less disruption of ψ m and reduced cell death in AKI. Importantly, TAT-GILZ increased perfusion of the ischemic-reperfused kidney but reduced tissue edema compared with TAT. Utilizing splenic T cells and bone marrow-derived neutrophils, we further showed marked reduction in the proliferation of Th cells in response to TAT-GILZ compared with response to TAT. Collectively, the results indicate that GILZ exerts renoprotection accompanied by the upregulation of the regulatory/suppressive arm of immunity in AKI, likely via regulating cross talk between T cells and neutrophils.


Assuntos
Injúria Renal Aguda/tratamento farmacológico , Glucocorticoides/farmacologia , Zíper de Leucina/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Linfócitos T Reguladores/efeitos dos fármacos , Células Th17/efeitos dos fármacos , Injúria Renal Aguda/metabolismo , Animais , Regulação da Expressão Gênica/efeitos dos fármacos , Interleucina-10/metabolismo , Interleucina-17/metabolismo , Rim/efeitos dos fármacos , Rim/metabolismo , Ativação Linfocitária/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Linfócitos T Reguladores/metabolismo , Células Th17/metabolismo , Transativadores/metabolismo , Fatores de Transcrição/metabolismo , Regulação para Cima/efeitos dos fármacos
5.
Clin Nephrol ; 86(9): 147-53, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27487355

RESUMO

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease. Studies have suggested a possible prognostic role of copeptin in determining the rate of progressive kidney function decline in ADPKD patients. However, it remains unresolved whether the changes in copeptin levels are specific for ADPKD or merely reflect a decline in glomerular filtration rate (GFR) regardless of the etiology of chronic kidney disease (CKD). METHODS: We performed a case-control study in ADPKD and non-ADPKD (control) patients. Patients were categorized based on the GFR-category (G-stage, KDIGO). We evaluated urea, creatinine, cystatin C, and copeptin in plasma and correlated these levels with estimated glomerular filtration rate (eGFR) (CKD-EPI). All p-values were two sided, and p < 0.05 was considered as statistically significant. RESULTS: We enrolled 112 ADPKD and 112 control patients. The median copeptin level was 10.72 (interquartile range (IQR) 5.21 - 26.21) pmol/L in the ADPKD group and 12.32 (IQR 4.47 - 30.73) pmol/L in the control group. The median copeptin level increased according to the G-stage in a progressive fashion and remained statistically significant across all G-stages and in both groups. Copeptin levels were not significantly different between ADPKD and control groups. We found a significant inverse correlation between copeptin level and eGFR (Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI)) in the ADPKD, r = -0.81 (p < 0.001), and in the control group, r = -0.76 (p < 0.001). CONCLUSIONS: Copeptin levels seem to be strongly correlated with renal function rather than the presence of ADPKD. Further prospective studies need to evaluate its role as a prognostic marker in the early stage of CKD for ADPKD progression.


Assuntos
Creatinina/sangue , Taxa de Filtração Glomerular/fisiologia , Glicopeptídeos/sangue , Rim/fisiopatologia , Rim Policístico Autossômico Dominante/sangue , Adulto , Idoso , Biomarcadores/sangue , Estudos de Casos e Controles , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Rim Policístico Autossômico Dominante/fisiopatologia , Prognóstico , Estudos Prospectivos
6.
Hippocampus ; 24(2): 165-77, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24123649

RESUMO

The involvement of the hippocampus in learning processes and major brain diseases makes it an ideal candidate to investigate possible ways to devise effective therapies for memory-related pathologies like Alzheimer's Disease (AD). It has been previously reported that augmenting CREB activity increases the synaptic Long-Term Potentiation (LTP) magnitude in CA1 pyramidal neurons and their intrinsic excitability in healthy rodents. It has also been suggested that hippocampal CREB signaling is likely to be down-regulated during AD, possibly degrading memory functions. Therefore, the concept of CREB-based memory enhancers, i.e. drugs that would boost memory by activation of CREB, has emerged. Here, using a model of a CA1 microcircuit, we investigate whether hippocampal CA1 pyramidal neuron properties altered by increasing CREB activity may contribute to improve memory storage and recall. With a set of patterns presented to a network, we find that the pattern recall quality under AD-like conditions is significantly better when boosting CREB function with respect to control. The results are robust and consistent upon increasing the synaptic damage expected by AD progression, supporting the idea that the use of CREB-based therapies could provide a new approach to treat AD.


Assuntos
Região CA1 Hipocampal/citologia , Proteína de Ligação a CREB/metabolismo , Rememoração Mental/fisiologia , Modelos Neurológicos , Neurônios/fisiologia , Animais , Região CA1 Hipocampal/metabolismo , Simulação por Computador , Humanos , Plasticidade Neuronal/fisiologia
7.
Animals (Basel) ; 13(13)2023 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-37443862

RESUMO

The on-site inspection of the scene of an animal cadaver is crucial for a correct interpretation of the autopsy results, to determine the manner, method, and cause of death. This information plays a crucial role in the control of public health including the prevention of zoonoses. It is also fundamental for the recognition and the contrast of crimes against animals and to animal abuse phenomena, considered an alert sign of an anti-social or violent behavior of humans. Today the best veterinary procedure requires an accurate collection of the evidence at the scene that can be then handed to experts belonging to other forensic disciplines for further evaluation and data interpretation. In this paper authors suggest a form aiming to facilitate either the on-site and the autopsy activities, as a guarantee of the quality of the forensic process starting from the discovery scene up to the reconstruction of the case. Essential is training of non-medical personnel who often represent the first responder to be present on the scene. The form is inspired by the interdisciplinary form developed by the European Council of Legal Medicine and represents an initial tool to stimulate a multidisciplinary activity in close synergy with other forensic experts.

8.
iScience ; 26(1): 105728, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36582822

RESUMO

In Neurodevelopmental Disorders, alterations of synaptic plasticity may trigger structural changes in neuronal circuits involved in cognitive functions. This hypothesis was tested in mice carrying the human R451C mutation of Nlgn3 gene (NLG3R451C KI), found in some families with autistic children. To this aim, the spike time dependent plasticity (STDP) protocol was applied to immature GABAergic Mossy Fibers (MF)-CA3 connections in hippocampal slices from NLG3R451C KI mice. These animals failed to exhibit STD-LTP, an effect that persisted in adulthood when these synapses became glutamatergic. Similar results were obtained in mice lacking the Nlgn3 gene (NLG3 KO mice), suggesting a loss of function. The loss of STD-LTP was associated with a premature shift of GABA from the depolarizing to the hyperpolarizing direction, a reduced BDNF availability and TrkB phosphorylation at potentiated synapses. These effects may constitute a general mechanism underlying cognitive deficits in those forms of Autism caused by synaptic dysfunctions.

9.
J R Soc Interface ; 20(204): 20230160, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37403487

RESUMO

The ability of cells to reorganize in response to external stimuli is important in areas ranging from morphogenesis to tissue engineering. While nematic order is common in biological tissues, it typically only extends to small regions of cells interacting via steric repulsion. On isotropic substrates, elongated cells can co-align due to steric effects, forming ordered but randomly oriented finite-size domains. However, we have discovered that flat substrates with nematic order can induce global nematic alignment of dense, spindle-like cells, thereby influencing cell organization and collective motion and driving alignment on the scale of the entire tissue. Remarkably, single cells are not sensitive to the substrate's anisotropy. Rather, the emergence of global nematic order is a collective phenomenon that requires both steric effects and molecular-scale anisotropy of the substrate. To quantify the rich set of behaviours afforded by this system, we analyse velocity, positional and orientational correlations for several thousand cells over days. The establishment of global order is facilitated by enhanced cell division along the substrate's nematic axis, and associated extensile stresses that restructure the cells' actomyosin networks. Our work provides a new understanding of the dynamics of cellular remodelling and organization among weakly interacting cells.


Assuntos
Comportamento de Massa , Anisotropia , Divisão Celular
10.
J Comput Neurosci ; 33(2): 207-25, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22310969

RESUMO

Under sustained input current of increasing strength neurons eventually stop firing, entering a depolarization block. This is a robust effect that is not usually explored in experiments or explicitly implemented or tested in models. However, the range of current strength needed for a depolarization block could be easily reached with a random background activity of only a few hundred excitatory synapses. Depolarization block may thus be an important property of neurons that should be better characterized in experiments and explicitly taken into account in models at all implementation scales. Here we analyze the spiking dynamics of CA1 pyramidal neuron models using the same set of ionic currents on both an accurate morphological reconstruction and on its reduction to a single-compartment. The results show the specific ion channel properties and kinetics that are needed to reproduce the experimental findings, and how their interplay can drastically modulate the neuronal dynamics and the input current range leading to a depolarization block. We suggest that this can be one of the rate-limiting mechanisms protecting a CA1 neuron from excessive spiking activity.


Assuntos
Potenciais de Ação/fisiologia , Região CA1 Hipocampal/citologia , Hipocampo/citologia , Modelos Neurológicos , Dinâmica não Linear , Células Piramidais/fisiologia , Potenciais de Ação/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Fenômenos Biofísicos , Região CA1 Hipocampal/efeitos dos fármacos , Estimulação Elétrica , Agonistas de Aminoácidos Excitatórios/farmacologia , Técnicas In Vitro , N-Metilaspartato/farmacologia , Técnicas de Patch-Clamp , Ratos , Ratos Sprague-Dawley , Sinapses/efeitos dos fármacos , Sinapses/fisiologia , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico/farmacologia
11.
Proc Math Phys Eng Sci ; 478(2257): 20210879, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35153617

RESUMO

We study the active flow around isolated defects and the self-propulsion velocity of + 1 / 2 defects in an active nematic film with both viscous dissipation (with viscosity η ) and frictional damping Γ with a substrate. The interplay between these two dissipation mechanisms is controlled by the hydrodynamic dissipation length ℓ d = η / Γ that screens the flows. For an isolated defect, in the absence of screening from other defects, the size of the shear vorticity around the defect is controlled by the system size R . In the presence of friction that leads to a finite value of ℓ d , the vorticity field decays to zero on the lengthscales larger than ℓ d . We show that the self-propulsion velocity of + 1 / 2 defects grows with R in small systems where R < ℓ d , while in the infinite system limit or when R ≫ ℓ d , it approaches a constant value determined by ℓ d .

12.
Front Vet Sci ; 9: 898721, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35928107

RESUMO

The growth of human population has led, in recent years, to increasingly frequent contacts with the wild animals with which we share the territory, sometimes leading to negative interactions with them. The purpose of the study is to apply the codes contained in the 11th Revision of the International Classification of Diseases (ICD-11) method to investigate the cause and the manner of death, also to entrust the veterinarian with the task of recognizing and describing a suspected animal abuse as a sentinel indicator of violence toward humans and non-humans, thus expanding the concept of "One Health" from a forensic investigation perspective. The subjects recruited are wild mammals submitted for autopsy to the Pathology Unit of the Department of Veterinary Science, University of Parma, Italy, from 2015 to 2018. The manner and the cause of death of 167 wild animals of 16 different species have been investigated. When possible, an on-site inspection where the corpse was found was performed. Injuries were classified according to the on-line 11th Revision of the International Classification of Diseases method. Section 22 (Injury, poisoning or certain other consequences of external causes) was used to record the "immediate cause of death" (cause of death) and Section 23 (External causes of morbidity or mortality) was used to record the "underlying cause of death" (manner of death) for each animal. In most cases, death occurred as a result of road trauma but in some cases, abuse and voluntary killing were investigated. The recognition of non-accidental injuries is particularly important for both the defense in court of animals and for the connection between crimes committed against animals and against humans, known as "The Link". The use of the ICD-11 method, as a sort of summary of the autopsy report, was confirmed to be of great value for the clarity and simplicity of processing the data collected also by veterinary pathologists. The veterinary pathologists can use this evidence-based method with the aim of creating a national register and therefore, to understand the real extent of the human impact on wildlife and document it in a scientific and statistically usable way.

13.
J Neurosci ; 30(39): 13089-94, 2010 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-20881126

RESUMO

The etiology of Alzheimer's disease (AD) remains elusive. The "amyloid" hypothesis states that toxic action of accumulated ß-amyloid peptide (Aß) on synaptic function causes AD cognitive decline. This hypothesis is supported by analysis of familial AD (FAD)-based transgenic mouse models, where altered amyloid precursor protein (APP) processing leads to Aß accumulation correlating with hippocampal-dependent memory deficits. Some studies report prominent dentate gyrus (DG) glutamatergic plasticity alterations in these mice, while CA1 plasticity remains relatively unaffected. The "neurotrophic unbalance" hypothesis, on the other hand, states that AD-related loss of cholinergic signaling and altered APP processing are due to alterations in nerve growth factor (NGF) trophic support. This hypothesis is supported by analysis of the AD11 mouse, which exhibits chronic NGF deprivation during adulthood and displays AD-like pathology, including Aß accumulation and hippocampal-dependent memory deficits. In this study, we analyzed CA1 and DG glutamatergic plasticity in AD11 mice to evaluate whether these mice also share with FAD models a common phenotype in hippocampal synaptic dysfunction. We report that AD11 mice display age-dependent short- and long-term DG plasticity deficits, while CA1 plasticity remains relatively spared. We also report that both structures exhibit enhanced glutamatergic transmission under lower, yet physiological, neurotransmitter release conditions, a defect that should be considered when further evaluating hippocampal synaptic deficits underlying AD pathology. We conclude that severe deficits in DG plasticity represent another common denominator between these two etiologically different types of AD mouse models, independent of the initial insult (overexpression of FAD mutation or NGF deprivation).


Assuntos
Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Hipocampo/metabolismo , Hipocampo/fisiopatologia , Fator de Crescimento Neural/deficiência , Plasticidade Neuronal/genética , Doença de Alzheimer/fisiopatologia , Animais , Modelos Animais de Doenças , Ácido Glutâmico/fisiologia , Hipocampo/patologia , Transtornos da Memória/genética , Transtornos da Memória/metabolismo , Transtornos da Memória/patologia , Mesencéfalo/metabolismo , Mesencéfalo/patologia , Mesencéfalo/fisiopatologia , Camundongos , Camundongos Transgênicos , Fator de Crescimento Neural/genética , Técnicas de Cultura de Órgãos , Via Perfurante/metabolismo , Via Perfurante/patologia , Via Perfurante/fisiopatologia , Transmissão Sináptica/genética
14.
Rev Neurosci ; 22(4): 373-402, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21732714

RESUMO

Transgenic (Tg) mouse models of Alzheimer's disease (AD) are used to investigate mechanisms underlying disease pathology and identify therapeutic strategies. Most Tg AD models, which at least partly recapitulate the AD phenotype, are based on insertion of one or more human mutations (identified in Familial AD) into the mouse genome, with the notable exception of the anti-NGF mouse, which is based on the cholinergic unbalance hypothesis. It has recently emerged that impaired hippocampal synaptic function is an early detectable pathological alteration, well before the advanced stage of amyloid plaque accumulation and general cell death. Nevertheless, electrophysiological studies performed on different Tg models or on the same model by different research groups have yielded contrasting results. We therefore summarized data from original research papers studying hippocampal synaptic function using electrophysiology, to review what we have learned so far. We analyzed results obtained using the following Tg models: (1) single/multiple APP mutations; (2) single presenilin (PS) mutations; (3) APPxPS1 mutations; (4) APPxPS1xtau mutations (3xTg); and (5) anti-NGF expressing (AD11) mice. We observed that the majority of papers focus on excitatory basic transmission and long-term potentiation, while few studies evaluate inhibitory transmission and long-term depression. We searched for common synaptic alterations in the various models that might underlie the memory deficits observed in these mice. We also considered experimental variables that could explain differences in the reported results and briefly discuss successful rescue strategies. These analyses should prove useful for future design of electrophysiology experiments to assess hippocampal function in AD mouse models.


Assuntos
Doença de Alzheimer/patologia , Hipocampo/patologia , Plasticidade Neuronal/fisiologia , Sinapses/patologia , Doença de Alzheimer/genética , Precursor de Proteína beta-Amiloide/genética , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Transgênicos , Plasticidade Neuronal/genética , Presenilina-1/genética , Sinapses/genética
15.
J Bioenerg Biomembr ; 43(5): 507-18, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21833601

RESUMO

Most cancer cells, including GL15 glioblastoma cells, rely on glycolysis for energy supply. The effect of antiglycolytic bromopyruvate on respiratory parameters and viability of GL15 cells was investigated. Bromopyruvate caused Δψ(m) and MTT collapse, ATP decrease, and cell viability loss without involving apoptotic or necrotic pathways. The autophagy marker LC3-II was increased. Δψ(m) decrease was accompanied by reactive oxygen species (ROS) increase and cytochrome c (cyt c) disappearance, suggesting a link between free radical generation and intramitochondrial cyt c degradation. Indeed, the free radical inducer menadione caused a decrease in cyt c that was reversed by N-acetylcysteine. Cyt c is tightly bound to the inner mitochondrial membrane in GL15 cells, which may confer protein peroxidase activity, resulting in auto-oxidation and protein targeting to degradation in the presence of ROS. This process is directed towards impairment of the apoptotic cyt c cascade, although cells are committed to die.


Assuntos
Inibidores Enzimáticos/farmacologia , Glioblastoma/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/metabolismo , Membranas Mitocondriais/metabolismo , Piruvatos/farmacologia , Acetilcisteína/farmacologia , Trifosfato de Adenosina/biossíntese , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Citocromos c/metabolismo , Sequestradores de Radicais Livres/farmacologia , Glioblastoma/patologia , Glicólise/efeitos dos fármacos , Humanos , Mitocôndrias/patologia , Membranas Mitocondriais/patologia , Oxirredução/efeitos dos fármacos , Proteólise/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
16.
Leg Med (Tokyo) ; 50: 101861, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33667932

RESUMO

The best method of diatom identification in animal and human tissues is still an important discussion topic, in terms of effectiveness and reliability. In this technical note, authors propose a new method of extraction of diatoms using heated hydrogen peroxide from animal and human tissue samples. This method has been compared with the traditional method of digestion with acids. The results of the comparison show that heated hydrogen peroxide extraction is more efficient in terms of reduction of sediment, extraction of the material and preservation of diatoms proving to be a viable alternative to conventional approaches with acids in terms of costs and operator safety.


Assuntos
Diatomáceas , Animais , Afogamento , Temperatura Alta , Humanos , Peróxido de Hidrogênio , Pulmão , Reprodutibilidade dos Testes
17.
Acta Neuropathol Commun ; 9(1): 38, 2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-33750467

RESUMO

Retina and optic nerve are sites of extra-cerebral manifestations of Alzheimer's Disease (AD). Amyloid-ß (Aß) plaques and neurofibrillary tangles of hyperphosphorylated tau protein are detected in eyes from AD patients and transgenic animals in correlation with inflammation, reduction of synapses, visual deficits, loss of retinal cells and nerve fiber. However, neither the pathological relevance of other post-translational tau modifications-such as truncation with generation of toxic fragments-nor the potential neuroprotective action induced by their in vivo clearance have been investigated in the context of AD retinal degeneration. We have recently developed a monoclonal tau antibody (12A12mAb) which selectively targets the neurotoxic 20-22 kDa NH2-derived peptide generated from pathological truncation at the N-terminal domain of tau without cross-reacting with its full-length normal protein. Previous studies have shown that 12A12mAb, when intravenously (i.v.)-injected into 6-month-old Tg2576 animals, markedly improves their AD-like, behavioural and neuropathological syndrome. By taking advantage of this well-established tau-directed immunization regimen, we found that 12A12mAb administration also exerts a beneficial action on biochemical, morphological and metabolic parameters (i.e. APP/Aß processing, tau hyperphosphorylation, neuroinflammation, synaptic proteins, microtubule stability, mitochondria-based energy production, neuronal death) associated with ocular injury in the AD phenotype. These findings prospect translational implications in the AD field by: (1) showing for the first time that cleavage of tau takes part in several pathological changes occurring in vivo in affected retinas and vitreous bodies and that its deleterious effects are successfully antagonized by administration of the specific 12A12mAb; (2) shedding further insights on the tight connections between neurosensory retina and brain, in particular following tau-based immunotherapy. In our view, the parallel response we detected in this preclinical animal model, both in the eye and in the hippocampus, following i.v. 12A12mAb injection opens novel diagnostic and therapeutic avenues for the clinical management of cerebral and extracerebral AD signs in human beings.


Assuntos
Doença de Alzheimer/complicações , Imunoglobulinas Intravenosas/imunologia , Imunoglobulinas Intravenosas/uso terapêutico , Degeneração Retiniana/tratamento farmacológico , Degeneração Retiniana/etiologia , Proteínas tau/química , Proteínas tau/imunologia , Peptídeos beta-Amiloides , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Anticorpos/imunologia , Anticorpos/isolamento & purificação , Anticorpos/uso terapêutico , Modelos Animais de Doenças , Feminino , Imunoglobulinas Intravenosas/administração & dosagem , Camundongos , Camundongos Transgênicos , Mitocôndrias/patologia , Neurônios , Placa Amiloide/patologia , Retina/patologia , Degeneração Retiniana/patologia , Sinapses/metabolismo
18.
J Clin Invest ; 117(6): 1605-15, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17492054

RESUMO

Tsc22d3 coding for glucocorticoid-induced leucine zipper (GILZ) was initially identified as a dexamethasone-responsive gene involved in the control of T lymphocyte activation and apoptosis. However, the physiological role of this molecule and its function in the biological activity of glucocorticoids (GCs) has not been clarified. Here, we demonstrate that GILZ interacts directly with Ras in vitro and in vivo as shown by GILZ and Ras coimmunoprecipitation and colocalization upon PMA activation in primary mouse spleen T lymphocytes and thymus cells. The analysis of GILZ mutants showed that they bound Ras through the tuberous sclerosis complex box (TSC) and, depending on the Ras activation level, formed a trimeric complex with Ras and Raf, which we previously identified as a GILZ binder. As a consequence of these interactions, GILZ diminished the activation of Ras and Raf downstream targets including ERK1/2, AKT/PKB serine/threonine kinase, and retinoblastoma (Rb) phosphorylation and cyclin D1 expression, leading to inhibition of Ras- and Raf-dependent cell proliferation and Ras-induced NIH-3T3 transformation. GILZ silencing resulted in an increase in concanavalin A-induced T cell proliferation and, most notably, inhibition of dexamethasone antiproliferative effects. Together, these findings indicate that GILZ serves as a negative regulator of Ras- and Raf-induced proliferation and is an important mediator of the antiproliferative effect of GCs.


Assuntos
Proliferação de Células/efeitos dos fármacos , Dexametasona/farmacologia , Fatores de Transcrição/metabolismo , Proteínas ras/metabolismo , Animais , Linhagem Celular , Glucocorticoides/farmacologia , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos C3H , Mutação , Células NIH 3T3 , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transdução de Sinais , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Fatores de Transcrição/genética , Transfecção
19.
Curr Alzheimer Res ; 17(3): 259-268, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32091333

RESUMO

BACKGROUND: Clinical evidence indicates that patients affected by Alzheimer's Disease (AD) fail to form new memories although their memories for old events are intact. This amnesic pattern depends on the selective vulnerability to AD-neurodegeneration of the hippocampus, the brain region that sustains the formation of new memories, while cortical regions that store remote memories are spared. OBJECTIVE: To identify the cellular mechanisms underlying impaired recent memories and intact remote memories in a mouse model of AD. METHODS: Glutamatergic synaptic currents were recorded by patch-clamp in acute hippocampal and anterior Cingulate Cortical (aCC) slices of AD-like Tg2576 mice and Wild-type (Wt) littermates subjected to the Contextual Fear Conditioning (CFC) task or in naïve conditions. RESULTS: We identified a deficit in the formation of recent memories, but not in the recall of remote ones, in Tg2576 mice. With electrophysiological recordings, we detected CFC-induced modifications of the AMPA/NMDA ratio in CA1 pyramidal cells of Wt, but not Tg2576, mice one day after training. CFC-induced changes in the AMPA/NMDA ratio were also detected in the aCC of both Wt and Tg2576 mice 8 days after training. CONCLUSION: Our data suggest that in the early AD stages synaptic plasticity of CA1 synapses, crucial to form new memories, is lost, while plasticity of aCC synapses is intact and contributes to the persistence of long-term memories.


Assuntos
Doença de Alzheimer/fisiopatologia , Amnésia Anterógrada/fisiopatologia , Região CA1 Hipocampal/fisiologia , Giro do Cíngulo/fisiologia , Memória de Longo Prazo/fisiologia , Plasticidade Neuronal/fisiologia , Precursor de Proteína beta-Amiloide , Animais , Modelos Animais de Doenças , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Transmissão Sináptica/fisiologia
20.
J Immunol Res ; 2020: 6056373, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32185239

RESUMO

Innate lymphoid cells (ILCs) have emerged as largely tissue-resident archetypal cells of the immune system. We tested the hypotheses that renal ischemia-reperfusion injury (IRI) is a contributing factor to polarization of ILCs and that glucocorticoid-induced leucine zipper (GILZ) and cannabidiol regulate them in this condition. Mice subjected to unilateral renal IRI were treated with the following agents before restoration of renal blood flow: cannabidiol, DMSO, transactivator of transcription- (TAT-) GILZ, or the TAT peptide. Thereafter, kidney cells were prepared for flow cytometry analyses. Sham kidneys treated with either cannabidiol or TAT-GILZ displayed similar frequencies of each subset of ILCs compared to DMSO or TAT, respectively. Renal IRI increased ILC1s and ILC3s but reduced ILC2s compared to the sham group. Cannabidiol or TAT-GILZ treatment of IRI kidneys reversed this pattern as evidenced by reduced ILC1s and ILC3s but increased ILC2s compared to their DMSO- or TAT-treated counterparts. While TAT-GILZ treatment did not significantly affect cells positive for cannabinoid receptors subtype 2 (CB2+), cannabidiol treatment increased frequency of both CB2+ and GILZ-positive (GILZ+) cells of IRI kidneys. Subsequent studies showed that IRI reduced GILZ+ subsets of ILCs, an effect less marked for ILC2s. Treatment with cannabidiol increased frequencies of each subset of GILZ+ ILCs, but the effect was more marked for ILC2s. Indeed, cannabidiol treatment increased CB2+ GILZ+ ILC2s. Collectively, the results indicate that both cannabidiol and GILZ regulate ILC frequency and phenotype, in acute kidney injury, and that the effects of cannabidiol likely relate to modulation of endogenous GILZ.


Assuntos
Injúria Renal Aguda/metabolismo , Canabidiol/metabolismo , Rim/fisiologia , Linfócitos/metabolismo , Traumatismo por Reperfusão/metabolismo , Fatores de Transcrição/metabolismo , Injúria Renal Aguda/imunologia , Animais , Células Cultivadas , Citocinas/metabolismo , Modelos Animais de Doenças , Citometria de Fluxo , Humanos , Imunidade Inata , Linfócitos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Receptor Cross-Talk , Receptor CB2 de Canabinoide/metabolismo , Traumatismo por Reperfusão/imunologia , Células Th2/imunologia
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