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1.
Int J Mol Sci ; 25(2)2024 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-38256109

RESUMO

The available antipsychotics for schizophrenia (SZ) only reduce positive symptoms and do not significantly modify SZ neurobiology. This has raised the question of the robustness and translational value of methods employed during drug development. Electroencephalography (EEG)-based measures like evoked and spontaneous gamma oscillations are considered robust translational biomarkers as they can be recorded in both patients and animal models to probe a key mechanism underlying all SZ symptoms: the excitation/inhibition imbalance mediated by N-methyl-D-aspartate receptor (NMDAr) hypofunction. Understanding the effects of commercialized atypical antipsychotics on such measures could therefore contribute to developing better therapies for SZ. Yet, the effects of such drugs on these EEG readouts are unknown. Here, we studied the effect of the atypical antipsychotic aripiprazole on the gamma-band auditory steady-state response (ASSR), spontaneous gamma oscillations and behavioral features in a SZ rat model induced by the NMDAr antagonist MK-801. Interestingly, we found that aripiprazole could not normalize MK-801-induced abnormalities in ASSR, spontaneous gamma oscillations or social interaction while it still improved MK-801-induced hyperactivity. Suggesting that aripiprazole is unable to normalize electrophysiological features underlying SZ symptoms, our results might explain aripiprazole's inefficacy towards the social interaction deficit in our model but also its limited efficacy against social symptoms in patients.


Assuntos
Antipsicóticos , Esquizofrenia , Humanos , Animais , Ratos , Aripiprazol/farmacologia , Esquizofrenia/tratamento farmacológico , Maleato de Dizocilpina/farmacologia , Antipsicóticos/farmacologia , Eletroencefalografia , Receptores de N-Metil-D-Aspartato
2.
Nutrients ; 15(21)2023 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-37960344

RESUMO

Early-life exposure to high-fat diets (HF) can program metabolic and cognitive alterations in adult offspring. Although the hippocampus plays a crucial role in memory and metabolic homeostasis, few studies have reported the impact of maternal HF on this structure. We assessed the effects of maternal HF during lactation on physiological, metabolic, and cognitive parameters in young adult offspring mice. To identify early-programming mechanisms in the hippocampus, we developed a multi-omics strategy in male and female offspring. Maternal HF induced a transient increased body weight at weaning, and a mild glucose intolerance only in 3-month-old male mice with no change in plasma metabolic parameters in adult male and female offspring. Behavioral alterations revealed by a Barnes maze test were observed both in 6-month-old male and female mice. The multi-omics strategy unveiled sex-specific transcriptomic and proteomic modifications in the hippocampus of adult offspring. These studies that were confirmed by regulon analysis show that, although genes whose expression was modified by maternal HF were different between sexes, the main pathways affected were similar with mitochondria and synapses as main hippocampal targets of maternal HF. The effects of maternal HF reported here may help to better characterize sex-dependent molecular pathways involved in cognitive disorders and neurodegenerative diseases.


Assuntos
Dieta Hiperlipídica , Efeitos Tardios da Exposição Pré-Natal , Animais , Camundongos , Feminino , Masculino , Humanos , Dieta Hiperlipídica/efeitos adversos , Obesidade/etiologia , Obesidade/metabolismo , Multiômica , Proteômica , Lactação , Hipocampo/metabolismo , Fenômenos Fisiológicos da Nutrição Materna/fisiologia , Efeitos Tardios da Exposição Pré-Natal/metabolismo
3.
J Clin Invest ; 132(22)2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36377661

RESUMO

Cisplatin is a potent chemotherapeutic drug that is widely used in the treatment of various solid cancers. However, its clinical effectiveness is strongly limited by frequent severe adverse effects, in particular nephrotoxicity and chemotherapy-induced peripheral neuropathy. Thus, there is an urgent medical need to identify novel strategies that limit cisplatin-induced toxicity. In the present study, we show that the FDA-approved adenosine A2A receptor antagonist istradefylline (KW6002) protected from cisplatin-induced nephrotoxicity and neuropathic pain in mice with or without tumors. Moreover, we also demonstrate that the antitumoral properties of cisplatin were not altered by istradefylline in tumor-bearing mice and could even be potentiated. Altogether, our results support the use of istradefylline as a valuable preventive approach for the clinical management of patients undergoing cisplatin treatment.


Assuntos
Antineoplásicos , Neuralgia , Animais , Camundongos , Cisplatino/efeitos adversos , Purinas/farmacologia , Neuralgia/induzido quimicamente , Receptor A2A de Adenosina , Antineoplásicos/efeitos adversos
4.
Cell Mol Life Sci ; 79(8): 431, 2022 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-35852606

RESUMO

Amyotrophic lateral sclerosis (ALS) is a fatal motoneuron (MN) disease characterized by protein misfolding and aggregation leading to cellular degeneration. So far neither biomarker, nor effective treatment has been found. ATP signaling and P2X4 receptors (P2X4) are upregulated in various neurodegenerative diseases. Here we show that several ALS-related misfolded proteins including mutants of SOD1 or TDP-43 lead to a significant increase in surface P2X4 receptor density and function in vitro. In addition, we demonstrate in the spinal the cord of SOD1-G93A (SOD1) mice that misfolded SOD1-G93A proteins directly interact with endocytic adaptor protein-2 (AP2); thus, acting as negative competitors for the interaction between AP2 and P2X4, impairing constitutive P2X4 endocytosis. The higher P2X4 surface density was particularly observed in peripheral macrophages of SOD1 mice before the onset and during the progression of ALS symptoms positioning P2X4 as a potential early biomarker for ALS. P2X4 expression was also upregulated in spinal microglia of SOD1 mice during ALS and affect microglial inflammatory responses. Importantly, we report using double transgenic SOD1 mice expressing internalization-defective P2X4mCherryIN knock-in gene or invalidated for the P2X4 gene that P2X4 is instrumental for motor symptoms, ALS progression and survival. This study highlights the role of P2X4 in the pathophysiology of ALS and thus its potential for the development of biomarkers and treatments. We also decipher the molecular mechanism by which misfolded proteins related to ALS impact P2X4 trafficking at early pathological stage in cells expressing-P2X4.


Assuntos
Esclerose Lateral Amiotrófica , Doença dos Neurônios Motores , Receptores Purinérgicos P2X4 , Superóxido Dismutase-1 , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/patologia , Animais , Modelos Animais de Doenças , Progressão da Doença , Camundongos , Camundongos Transgênicos , Doença dos Neurônios Motores/genética , Doença dos Neurônios Motores/metabolismo , Doença dos Neurônios Motores/patologia , Neurônios Motores/metabolismo , Neurônios Motores/patologia , Receptores Purinérgicos P2X4/genética , Receptores Purinérgicos P2X4/metabolismo , Medula Espinal/metabolismo , Superóxido Dismutase-1/genética , Superóxido Dismutase-1/metabolismo
5.
J Clin Invest ; 132(12)2022 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-35536645

RESUMO

Caffeine is the most widely consumed psychoactive substance in the world. Strikingly, the molecular pathways engaged by its regular consumption remain unclear. We herein addressed the mechanisms associated with habitual (chronic) caffeine consumption in the mouse hippocampus using untargeted orthogonal omics techniques. Our results revealed that chronic caffeine exerts concerted pleiotropic effects in the hippocampus at the epigenomic, proteomic, and metabolomic levels. Caffeine lowered metabolism-related processes (e.g., at the level of metabolomics and gene expression) in bulk tissue, while it induced neuron-specific epigenetic changes at synaptic transmission/plasticity-related genes and increased experience-driven transcriptional activity. Altogether, these findings suggest that regular caffeine intake improves the signal-to-noise ratio during information encoding, in part through fine-tuning of metabolic genes, while boosting the salience of information processing during learning in neuronal circuits.


Assuntos
Cafeína , Proteômica , Animais , Cafeína/metabolismo , Cafeína/farmacologia , Hipocampo/metabolismo , Aprendizagem , Camundongos , Plasticidade Neuronal/fisiologia
6.
Front Mol Neurosci ; 15: 841892, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35250480

RESUMO

Alzheimer's disease (AD) is the leading cause of dementia. While impaired glucose homeostasis has been shown to increase AD risk and pathological loss of tau function, the latter has been suggested to contribute to the emergence of the glucose homeostasis alterations observed in AD patients. However, the links between tau impairments and glucose homeostasis, remain unclear. In this context, the present study aimed at investigating the metabolic phenotype of a new tau knock-in (KI) mouse model, expressing, at a physiological level, a human tau protein bearing the P301L mutation under the control of the endogenous mouse Mapt promoter. Metabolic investigations revealed that, while under chow diet tau KI mice do not exhibit significant metabolic impairments, male but not female tau KI animals under High-Fat Diet (HFD) exhibited higher insulinemia as well as glucose intolerance as compared to control littermates. Using immunofluorescence, tau protein was found colocalized with insulin in the ß cells of pancreatic islets in both mouse (WT, KI) and human pancreas. Isolated islets from tau KI and tau knock-out mice exhibited impaired glucose-stimulated insulin secretion (GSIS), an effect recapitulated in the mouse pancreatic ß-cell line (MIN6) following tau knock-down. Altogether, our data indicate that loss of tau function in tau KI mice and, particularly, dysfunction of pancreatic ß cells might promote glucose homeostasis impairments and contribute to metabolic changes observed in AD.

7.
Neuropharmacology ; 209: 108999, 2022 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-35181375

RESUMO

Due to the pathophysiological complexity of Alzheimer's disease, multitarget approaches able to mitigate several pathogenic mechanisms are of interest. Previous studies have pointed to the neuroprotective potential of Doxycycline (Dox), a safe and inexpensive second-generation tetracycline. Dox has been particularly reported to slow down aggregation of misfolded proteins but also to mitigate neuroinflammatory processes. Here, we have evaluated the pre-clinical potential of Dox in the APP/PS1 mouse model of amyloidogenesis. Dox was provided to APP/PS1 mice from the age of 8 months, when animals already exhibit amyloid pathology and memory deficits. Spatial memory was then evaluated from 9 to 10 months of age. Our data demonstrated that Dox moderately improved the spatial memory of APP/PS1 mice without exerting major effect on amyloid lesions. While Dox did not alleviate overall glial reactivity, we could evidence that it rather enhanced the amyloid-dependent upregulation of several neuroinflammatory markers such as CCL3 and CCL4. Finally, Dox exerted differentially regulated the levels of synaptic proteins in the hippocampus and the cortex of APP/PS1 mice. Overall, these observations support that chronic Dox delivery does not provide major pathophysiological improvements in the APP/PS1 mouse model.


Assuntos
Doença de Alzheimer , Precursor de Proteína beta-Amiloide , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Modelos Animais de Doenças , Doxiciclina/farmacologia , Doxiciclina/uso terapêutico , Hipocampo/metabolismo , Camundongos , Camundongos Transgênicos , Presenilina-1/genética , Presenilina-1/metabolismo
8.
Sensors (Basel) ; 21(17)2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34502820

RESUMO

Internet of Things (IoT) applications are becoming more integrated into our society and daily lives, although many of them can expose the user to threats against their privacy. Therefore, we find that it is crucial to address the privacy requirements of most of such applications and develop solutions that implement, as far as possible, privacy by design in order to mitigate relevant threats. While in the literature we may find innovative proposals to enhance the privacy of IoT applications, many of those only focus on the edge layer. On the other hand, privacy by design approaches are required throughout the whole system (e.g., at the cloud layer), in order to guarantee robust solutions to privacy in IoT. With this in mind, we propose an architecture that leverages the properties of blockchain, integrated with other technologies, to address security and privacy in the context of IoT applications. The main focus of our proposal is to enhance the privacy of the users and their data, using the anonymisation properties of blockchain to implement user-controlled privacy. We consider an IoT application with mobility for smart vehicles as our usage case, which allows us to implement and experimentally evaluate the proposed architecture and mechanisms as a proof of concept. In this application, data related to the user's identity and location needs to be shared with security and privacy. Our proposal was implemented and experimentally validated in light of fundamental privacy and security requirements, as well as its performance. We found it to be a viable approach to security and privacy in IoT environments.

9.
Cell Rep ; 36(9): 109574, 2021 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-34469732

RESUMO

Neuroinflammation in patients with Alzheimer's disease (AD) and related mouse models has been recognized for decades, but the contribution of the recently described meningeal immune population to AD pathogenesis remains to be addressed. Here, using the 3xTg-AD model, we report an accumulation of interleukin-17 (IL-17)-producing cells, mostly γδ T cells, in the brain and the meninges of female, but not male, mice, concomitant with the onset of cognitive decline. Critically, IL-17 neutralization into the ventricles is sufficient to prevent short-term memory and synaptic plasticity deficits at early stages of disease. These effects precede blood-brain barrier disruption and amyloid-beta or tau pathology, implying an early involvement of IL-17 in AD pathology. When IL-17 is neutralized at later stages of disease, the onset of short-memory deficits and amyloidosis-related splenomegaly is delayed. Altogether, our data support the idea that cognition relies on a finely regulated balance of "inflammatory" cytokines derived from the meningeal immune system.


Assuntos
Doença de Alzheimer/metabolismo , Comportamento Animal , Encéfalo/metabolismo , Cognição , Mediadores da Inflamação/metabolismo , Interleucina-17/metabolismo , Linfócitos Intraepiteliais/metabolismo , Doenças Neuroinflamatórias/metabolismo , Sinapses/metabolismo , Doença de Alzheimer/patologia , Doença de Alzheimer/prevenção & controle , Doença de Alzheimer/psicologia , Animais , Anti-Inflamatórios/farmacologia , Anticorpos Monoclonais/farmacologia , Anticorpos Neutralizantes/farmacologia , Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Cognição/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Mediadores da Inflamação/antagonistas & inibidores , Interleucina-17/antagonistas & inibidores , Linfócitos Intraepiteliais/efeitos dos fármacos , Masculino , Memória de Curto Prazo , Camundongos da Linhagem 129 , Camundongos Transgênicos , Doenças Neuroinflamatórias/patologia , Doenças Neuroinflamatórias/prevenção & controle , Doenças Neuroinflamatórias/psicologia , Plasticidade Neuronal , Sinapses/efeitos dos fármacos , Sinapses/patologia
10.
Prog Neurobiol ; 206: 102139, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34391810

RESUMO

Alzheimer's disease is the most common form of dementia characterized by intracellular aggregates of hyperphosphorylated Tau protein and extracellular accumulation of amyloid ß (Aß) peptides. We previously demonstrated that the purinergic receptor P2X7 (P2X7) plays a major role in Aß-mediated neurodegeneration but the relationship between P2X7 and Tau remained overlooked. Such a link was supported by cortical upregulation of P2X7 in patients with various type of frontotemporal lobar degeneration, including mutation in the Tau-coding gene, MAPT, as well as in the brain of a Tauopathy mouse model (THY-Tau22). Subsequent phenotype analysis of P2X7-deficient Tau mice revealed the instrumental impact of this purinergic receptor. Indeed, while P2X7-deficiency had a moderate effect on Tau pathology itself, we observed a significant reduction of microglia activation and of Tau-related inflammatory mediators, particularly CCL4. Importantly, P2X7 deletion ultimately rescued synaptic plasticity and memory impairments of Tau mice. Altogether, the present data support a contributory role of P2X7 dysregulation on processes governing Tau-induced brain anomalies. Due to the convergent role of P2X7 blockade in both Aß and Tau background, P2X7 inhibitors might prove to be ideal candidate drugs to curb the devastating cognitive decline in Alzheimer's disease and Tauopathies.


Assuntos
Doença de Alzheimer , Receptores Purinérgicos P2X7/deficiência , Tauopatias , Doença de Alzheimer/genética , Peptídeos beta-Amiloides , Animais , Cognição , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Transgênicos , Tauopatias/genética , Proteínas tau/genética
11.
Brain ; 144(10): 3142-3158, 2021 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-34086871

RESUMO

Traumatic brain injury (TBI) leads to major brain anatomopathological damages underlined by neuroinflammation, oxidative stress and progressive neurodegeneration, ultimately leading to motor and cognitive deterioration. The multiple pathological events resulting from TBI can be addressed not by a single therapeutic approach, but rather by a synergistic biotherapy capable of activating a complementary set of signalling pathways and providing synergistic neuroprotective, anti-inflammatory, antioxidative, and neurorestorative activities. Human platelet lysate might fulfil these requirements as it is composed of a plethora of biomolecules readily accessible as a TBI biotherapy. In the present study, we tested the therapeutic potential of human platelet lysate using in vitro and in vivo models of TBI. We first prepared and characterized platelet lysate from clinical-grade human platelet concentrates. Platelets were pelletized, lysed by three freeze-thaw cycles, and centrifuged. The supernatant was purified by 56°C 30 min heat treatment and spun to obtain the heat-treated platelet pellet lysate that was characterized by ELISA and proteomic analyses. Two mouse models were used to investigate platelet lysate neuroprotective potential. The injury was induced by an in-house manual controlled scratching of the animals' cortex or by controlled cortical impact injury. The platelet lysate treatment was performed by topical application of 60 µl in the lesioned area, followed by daily 60 µl intranasal administration from Day 1 to 6 post-injury. Platelet lysate proteomics identified over 1000 proteins including growth factors, neurotrophins, and antioxidants. ELISA detected several neurotrophic and angiogenic factors at ∼1-50 ng/ml levels. We demonstrate, using two mouse models of TBI, that topical application and intranasal platelet lysate consistently improved mouse motor function in the beam and rotarod tests, mitigated cortical neuroinflammation, and oxidative stress in the injury area, as revealed by downregulation of pro-inflammatory genes and the reduction in reactive oxygen species levels. Moreover, platelet lysate treatment reduced the loss of cortical synaptic proteins. Unbiased proteomic analyses revealed that heat-treated platelet pellet lysate reversed several pathways promoted by both controlled cortical impact and cortical brain scratch and related to transport, postsynaptic density, mitochondria or lipid metabolism. The present data strongly support, for the first time, that human platelet lysate is a reliable and effective therapeutic source of neurorestorative factors. Therefore, brain administration of platelet lysate is a therapeutical strategy that deserves serious and urgent consideration for universal brain trauma treatment.


Assuntos
Terapia Biológica/métodos , Plaquetas/metabolismo , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/terapia , Administração Intranasal , Animais , Lesões Encefálicas Traumáticas/patologia , Linhagem Celular Tumoral , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL
12.
Acta Neuropathol Commun ; 9(1): 112, 2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-34158119

RESUMO

Tau pathology is instrumental in the gradual loss of neuronal functions and cognitive decline in tauopathies, including Alzheimer's disease (AD). Earlier reports showed that adenosine metabolism is abnormal in the brain of AD patients while consequences remained ill-defined. Herein, we aimed at investigating whether manipulation of adenosine tone would impact Tau pathology, associated molecular alterations and subsequent neurodegeneration. We demonstrated that treatment with an inhibitor (J4) of equilibrative nucleoside transporter 1 (ENT1) exerted beneficial effects in a mouse model of Tauopathy. Treatment with J4 not only reduced Tau hyperphosphorylation but also rescued memory deficits, mitochondrial dysfunction, synaptic loss, and abnormal expression of immune-related gene signatures. These beneficial effects were particularly ascribed to the ability of J4 to suppress the overactivation of AMPK (an energy reduction sensor), suggesting that normalization of energy dysfunction mitigates neuronal dysfunctions in Tauopathy. Collectively, these data highlight that targeting adenosine metabolism is a novel strategy for tauopathies.


Assuntos
Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Transportador Equilibrativo 1 de Nucleosídeo/antagonistas & inibidores , Tauopatias/metabolismo , Tauopatias/patologia , Animais , Encéfalo/metabolismo , Modelos Animais de Doenças , Humanos , Camundongos
13.
Front Neurol ; 12: 654850, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34054698

RESUMO

Purinergic signaling regulates neuronal and glial cell functions in the healthy CNS. In neurodegenerative diseases, purinergic signaling becomes dysregulated and can affect disease-associated phenotypes of glial cells. In this review, we discuss how cell-specific expression patterns of purinergic signaling components change in neurodegeneration and how dysregulated glial purinergic signaling and crosstalk may contribute to disease pathophysiology, thus bearing promising potential for the development of new therapeutical options for neurodegenerative diseases.

14.
Inflammopharmacology ; 29(3): 735-752, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33881683

RESUMO

This study aims to investigate the activity of n-hexane, ethyl acetate and butanol fractions obtained from Arrabidaea chica Verlot against MIA-induced osteoarthritis (OA). The antinociceptive potentials of each fraction were evaluated through a cyclooxygenase (COX) 1 and 2 inhibition test and an in vivo OA-model. In addition, toxicity assessments in the liver, spleen and kidney, as well as radiographic and histopathological knee analyses, were performed. The chemical composition of the n-hexane fraction was elucidated, and a molecular docking protocol was carried out to identify which compounds are associated with the detected bioactivity. The n-hexane A. chica fraction preferentially inhibits COX-2, with 90% inhibition observed at 10 µg/mL. The fractions also produced significant improvements in OA incapacity, motor activity and hyperalgesia parameters and in radiological knee conditions. However, concerning the histopathological evaluations, these improvements were only significant in the hexane and ethyl acetate fraction treatments, which resulted in better average scores, suggesting that these fractions slow OA-promoted joint injury progression. Histopathological organ analyses indicate that the fractions are not toxic to animals. Twenty compounds were identified in the n-hexane fraction, comprising fatty acids, terpenes and phytosterols. In silico analyses indicate the presence of favourable interactions between some of the identified compounds and the COX-2 enzyme, mainly concerning alpha-tocopherol (Vitamin E), squalene and beta-sitosterol. The findings indicate that A. chica fractions display analgesic, anti-inflammatory properties, are non-toxic and are able to slow OA progression, and may, therefore, be prioritized as natural products in OA human clinical trials.


Assuntos
Analgésicos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Osteoartrite/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Plantas Medicinais , Analgésicos/isolamento & purificação , Analgésicos/farmacologia , Animais , Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/farmacologia , Masculino , Simulação de Acoplamento Molecular/métodos , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Osteoartrite/metabolismo , Osteoartrite/patologia , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Estrutura Secundária de Proteína , Ratos , Ratos Wistar
15.
Brain ; 144(4): 1167-1182, 2021 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-33842937

RESUMO

Deposits of different abnormal forms of tau in neurons and astrocytes represent key anatomo-pathological features of tauopathies. Although tau protein is highly enriched in neurons and poorly expressed by astrocytes, the origin of astrocytic tau is still elusive. Here, we used innovative gene transfer tools to model tauopathies in adult mouse brains and to investigate the origin of astrocytic tau. We showed in our adeno-associated virus (AAV)-based models and in Thy-Tau22 transgenic mice that astrocytic tau pathology can emerge secondarily to neuronal pathology. By designing an in vivo reporter system, we further demonstrated bidirectional exchanges of tau species between neurons and astrocytes. We then determined the consequences of tau accumulation in astrocytes on their survival in models displaying various status of tau aggregation. Using stereological counting of astrocytes, we report that, as for neurons, soluble tau species are highly toxic to some subpopulations of astrocytes in the hippocampus, whereas the accumulation of tau aggregates does not affect their survival. Thus, astrocytes are not mere bystanders of neuronal pathology. Our results strongly suggest that tau pathology in astrocytes may significantly contribute to clinical symptoms.


Assuntos
Astrócitos/patologia , Hipocampo/patologia , Tauopatias/patologia , Proteínas tau/toxicidade , Animais , Humanos , Masculino , Camundongos , Neurônios/patologia , Agregados Proteicos , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/toxicidade , Tauopatias/metabolismo , Proteínas tau/genética , Proteínas tau/metabolismo
16.
Brain ; 142(11): 3636-3654, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31599329

RESUMO

Accumulating data support the role of tau pathology in cognitive decline in ageing and Alzheimer's disease, but underlying mechanisms remain ill-defined. Interestingly, ageing and Alzheimer's disease have been associated with an abnormal upregulation of adenosine A2A receptor (A2AR), a fine tuner of synaptic plasticity. However, the link between A2AR signalling and tau pathology has remained largely unexplored. In the present study, we report for the first time a significant upregulation of A2AR in patients suffering from frontotemporal lobar degeneration with the MAPT P301L mutation. To model these alterations, we induced neuronal A2AR upregulation in a tauopathy mouse model (THY-Tau22) using a new conditional strain allowing forebrain overexpression of the receptor. We found that neuronal A2AR upregulation increases tau hyperphosphorylation, potentiating the onset of tau-induced memory deficits. This detrimental effect was linked to a singular microglial signature as revealed by RNA sequencing analysis. In particular, we found that A2AR overexpression in THY-Tau22 mice led to the hippocampal upregulation of C1q complement protein-also observed in patients with frontotemporal lobar degeneration-and correlated with the loss of glutamatergic synapses, likely underlying the observed memory deficits. These data reveal a key impact of overactive neuronal A2AR in the onset of synaptic loss in tauopathies, paving the way for new therapeutic approaches.


Assuntos
Complemento C1q/metabolismo , Neurônios/metabolismo , Receptor A2A de Adenosina/genética , Receptor A2A de Adenosina/metabolismo , Sinapses/patologia , Tauopatias/genética , Tauopatias/patologia , Animais , Autopsia , Degeneração Lobar Frontotemporal/genética , Degeneração Lobar Frontotemporal/metabolismo , Hipocampo/metabolismo , Hipocampo/patologia , Humanos , Transtornos da Memória/etiologia , Transtornos da Memória/psicologia , Camundongos , Camundongos Transgênicos , Mutação , Aprendizagem Espacial , Tauopatias/psicologia , Proteínas tau/genética
17.
Glia ; 67(12): 2329-2342, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31328322

RESUMO

Adenosine A2A receptors (A2A R) are modulators of various physiological processes essential for brain homeostasis and fine synaptic tuning. In certain neurodegenerative conditions, notably Alzheimer's disease (AD), A2A Rs are pathologically upregulated in neurons but also in astrocytes. In that context, the use of A2A Rs inhibitors, normalizing impaired receptor function, is seen as a potential therapeutic strategy. However, the impact of A2A R alterations, particularly in astrocytes, is not fully understood. Here, we investigated the effect of A2A R overexpression on transcriptional deregulation in primary astrocytic cultures. By performing whole transcriptome analysis, we found that A2A R overexpression promotes robust transcriptional changes, mostly affecting immune response, angiogenesis, and cell activation-related genes. Importantly, we observed that treatment with SCH58261, a selective A2A R antagonist, restored the expression levels of several inflammatory and astrocytic activation-related genes, such as Interleukin-1beta and vimentin. This supports the notion that A2A R blockade could restore some astrocytic dysfunctions associated with abnormal A2A R expression, further arguing for a potential beneficial impact of receptor antagonists in A2A R-induced transcriptional deregulation, inflammation, and astrogliosis. Overall, our findings provide novel insights into the putative impact of A2A R overexpression on transcriptional deregulation in astrocytes, thereby opening novel avenues for the use of A2A R antagonists as potential therapeutic strategy in neurodegenerative diseases.


Assuntos
Antagonistas do Receptor A2 de Adenosina/farmacologia , Astrócitos/fisiologia , Receptor A2A de Adenosina/genética , Receptor A2A de Adenosina/metabolismo , Transcrição Gênica/fisiologia , Animais , Animais Recém-Nascidos , Astrócitos/efeitos dos fármacos , Células Cultivadas , Redes Reguladoras de Genes/efeitos dos fármacos , Redes Reguladoras de Genes/fisiologia , Camundongos , Transcrição Gênica/efeitos dos fármacos
18.
Sensors (Basel) ; 19(5)2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30823677

RESUMO

This paper introduces a strategy for the path planning problem for platforms with limited sensor and processing capabilities. The proposed algorithm does not require any prior information but assumes that a mapping algorithm is used. If enough information is available, a global path planner finds sub-optimal collision-free paths within the known map. For the real time obstacle avoidance task, a simple and cost-efficient local planner is used, making the algorithm a hybrid global and local planning solution. The strategy was tested in a real, cluttered environment experiment using the Pioneer P3-DX and the Xbox 360 kinect sensor, to validate and evaluate the algorithm efficiency.

19.
Neurobiol Dis ; 125: 14-22, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30665005

RESUMO

Accumulation of hyper-phosphorylated and aggregated Tau proteins is a neuropathological hallmark of Alzheimer's Disease (AD) and Tauopathies. AD patient brains also exhibit insulin resistance. Whereas, under normal physiological conditions insulin signaling in the brain mediates plasticity and memory formation, it can also regulate peripheral energy homeostasis. Thus, in AD, brain insulin resistance affects both cognitive and metabolic changes described in these patients. While a role of Aß oligomers and APOE4 towards the development of brain insulin resistance emerged, contribution of Tau pathology has been largely overlooked. Our recent data demonstrated that one of the physiological function of Tau is to sustain brain insulin signaling. We postulated that under pathological conditions, hyper-phosphorylated/aggregated Tau is likely to lose this function and to favor the development of brain insulin resistance. This hypothesis was substantiated by observations from patient brains with pure Tauopathies. To address the potential link between Tau pathology and brain insulin resistance, we have evaluated the brain response to insulin in a transgenic mouse model of AD-like Tau pathology (THY-Tau22). Using electrophysiological and biochemical evaluations, we surprisingly observed that, at a time when Tau pathology and cognitive deficits are overt and obvious, the hippocampus of THY-Tau22 mice exhibits enhanced response to insulin. In addition, we demonstrated that the ability of i.c.v. insulin to promote body weight loss is enhanced in THY-Tau22 mice. In line with this, THY-Tau22 mice exhibited a lower body weight gain, hypoleptinemia and hypoinsulinemia and finally a metabolic resistance to high-fat diet. The present data highlight that the brain of transgenic Tau mice exhibit enhanced brain response to insulin. Whether these observations are ascribed to the development of Tau pathology, and therefore relevant to human Tauopathies, or unexpectedly results from the Tau transgene overexpression is debatable and discussed.


Assuntos
Encéfalo/metabolismo , Insulina/metabolismo , Tauopatias/metabolismo , Proteínas tau/metabolismo , Animais , Resistência à Insulina/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas tau/genética
20.
Front Neurosci ; 12: 520, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30123104

RESUMO

Alzheimer's disease (AD) is the most common neurodegenerative disorder in elderly people. AD is characterized by a progressive cognitive decline and it is neuropathologically defined by two hallmarks: extracellular deposits of aggregated ß-amyloid (Aß) peptides and intraneuronal fibrillar aggregates of hyper- and abnormally phosphorylated Tau proteins. AD results from multiple genetic and environmental risk factors. Epidemiological studies reported beneficial effects of caffeine, a non-selective adenosine receptors antagonist. In the present review, we discuss the impact of caffeine and of adenosinergic system modulation on AD, in terms of pathology and therapeutics.

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