RESUMO
Lyme carditis is an extracutaneous manifestation of Lyme disease characterized by episodes of atrioventricular block of varying degrees and additional, less reported cardiomyopathies. The molecular changes associated with the response to Borrelia burgdorferi over the course of infection are poorly understood. Here, we identify broad transcriptomic and proteomic changes in the heart during infection that reveal a profound down-regulation of mitochondrial components. We also describe the long-term functional modulation of macrophages exposed to live bacteria, characterized by an augmented glycolytic output, increased spirochetal binding and internalization, and reduced inflammatory responses. In vitro, glycolysis inhibition reduces the production of tumor necrosis factor (TNF) by memory macrophages, whereas in vivo, it produces the reversion of the memory phenotype, the recovery of tissue mitochondrial components, and decreased inflammation and spirochetal burdens. These results show that B. burgdorferi induces long-term, memory-like responses in macrophages with tissue-wide consequences that are amenable to be manipulated in vivo.
Assuntos
Borrelia burgdorferi/imunologia , Cardiomiopatias/etiologia , Memória Imunológica , Doença de Lyme/imunologia , Macrófagos/fisiologia , Animais , Cardiomiopatias/imunologia , Cardiomiopatias/microbiologia , Cardiomiopatias/patologia , Células Cultivadas , Endocardite Bacteriana/complicações , Endocardite Bacteriana/imunologia , Endocardite Bacteriana/microbiologia , Endocardite Bacteriana/patologia , Feminino , Células HEK293 , Coração/microbiologia , Humanos , Doença de Lyme/patologia , Ativação de Macrófagos/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/imunologia , Miócitos Cardíacos/microbiologia , Miócitos Cardíacos/patologia , Células RAW 264.7RESUMO
Morphogenesis is driven by small cell shape changes that modulate tissue organization. Apical surfaces of proliferating epithelial sheets have been particularly well studied. Currently, it is accepted that a stereotyped distribution of cellular polygons is conserved in proliferating tissues among metazoans. In this work, we challenge these previous findings showing that diverse natural packed tissues have very different polygon distributions. We use Voronoi tessellations as a mathematical framework that predicts this diversity. We demonstrate that Voronoi tessellations and the very different tissues analysed share an overriding restriction: the frequency of polygon types correlates with the distribution of cell areas. By altering the balance of tensions and pressures within the packed tissues using disease, genetic or computer model perturbations, we show that as long as packed cells present a balance of forces within tissue, they will be under a physical constraint that limits its organization. Our discoveries establish a new framework to understand tissue architecture in development and disease.
Assuntos
Fenômenos Químicos , Células Epiteliais/fisiologia , Morfogênese , Animais , Forma Celular , Células Cultivadas , Galinhas , Drosophila , Humanos , Pressão Hidrostática , Modelos Biológicos , Modelos TeóricosRESUMO
Glial-derived neurotrophic factor (GDNF) has been proposed as a potent neurotrophic factor with the potential to cure neurodegenerative diseases. In the cochlea, GDNF has been detected in auditory neurons and sensory receptor cells and its expression is upregulated upon trauma. Moreover, the application of GDNF in different animal models of deafness has shown its capacity to prevent hearing loss and promoted its future use in therapeutic trials in humans. In the present study we have examined the endogenous requirement of GDNF during auditory development in mice. Using a lacZ knockin allele we have confirmed the expression of GDNF in the cochlea including its sensory regions during development. Global inactivation of GDNF throughout the hearing system using a Foxg1-Cre line causes perinatal lethality but reveals no apparent defects during formation of the cochlea. Using TrkC-Cre and Atoh1-Cre lines, we were able to generate viable mutants lacking GDNF in auditory neurons or both auditory neurons and sensory hair cells. These mutants show normal frequency-dependent auditory thresholds. However, mechanoelectrical response properties of outer hair cells (OHCs) in TrkC-Cre GDNF mutants are altered at low thresholds. Furthermore, auditory brainstem wave analysis shows an abnormal increase of wave I. On the other hand, Atoh1-Cre GDNF mutants show normal OHC function but their auditory brainstem wave pattern is reduced at the levels of wave I, III and IV. These results show that GDNF expression during the development is required to maintain functional hearing at different levels of the auditory system.
Assuntos
Fator Neurotrófico Derivado de Linhagem de Célula Glial/deficiência , Fator Neurotrófico Derivado de Linhagem de Célula Glial/fisiologia , Audição/fisiologia , Animais , Limiar Auditivo , Cóclea/metabolismo , Orelha Interna/metabolismo , Potenciais Evocados Auditivos do Tronco Encefálico , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Células Ciliadas Auditivas/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos TransgênicosRESUMO
Olive pitting, slicing and stuffing machines (DRR in Spanish) are characterized by the fact that their optimal functioning is based on appropriate adjustments. Traditional systems are not completely reliable because their minimum error rate is 1-2%, which can result in fruit loss, since the pitting process is not infallible, and food safety issues can arise. Such minimum errors are impossible to remove through mechanical adjustments. In order to achieve this objective, an innovative solution must be provided in order to remove errors at operating speed rates over 2500 olives/min. This work analyzes the appropriate placement of olives in the pockets of the feed chain by using the following items: (1) An IoT System to control the DRR machine and the data analysis. (2) A computer vision system with an external shot camera and a LED lighting system, which takes a picture of every pocket passing in front of the camera. (3) A chip with a neural network for classification that, once trained, classifies between four possible pocket cases: empty, normal, incorrectly de-stoned olives at any angles (also known as a "boat"), and an anomalous case (foreign elements such as leafs, small branches or stones, two olives or small parts of olives in the same pocket). The main objective of this paper is to illustrate how with the use of a system based on IoT and a physical chip (NeuroMem CM1K, General Vision Inc.) with neural networks for sorting purposes, it is possible to optimize the functionality of this type of machine by remotely analyzing the data obtained. The use of classifying hardware allows it to work at the nominal operating speed for these machines. This would be limited if other classifying techniques based on software were used.
RESUMO
The mammalian pancreas is densely innervated by both the sympathetic and parasympathetic nervous systems, which control exocrine and endocrine secretion. During embryonic development, neural crest cells migrating in a rostrocaudal direction populate the gut, giving rise to neural progenitor cells. Recent studies in mice have shown that neural crest cells enter the pancreatic epithelium at E11.5. However, the cues that guide the migration of neural progenitors into the pancreas are poorly defined. In this study we identify glial cell line-derived neurotrophic factor (GDNF) as a key player in this process. GDNF displays a dynamic expression pattern during embryonic development that parallels the chronology of migration and differentiation of neural crest derivatives in the pancreas. Conditional inactivation of Gdnf in the pancreatic epithelium results in a dramatic loss of neuronal and glial cells and in reduced parasympathetic innervation in the pancreas. Importantly, the innervation of other regions of the gut remains unaffected. Analysis of Gdnf mutant mouse embryos and ex vivo experiments indicate that GDNF produced in the pancreas acts as a neurotrophic factor for gut-resident neural progenitor cells. Our data further show that exogenous GDNF promotes the proliferation of pancreatic progenitor cells in organ culture. In summary, our results point to GDNF as crucial for the development of the intrinsic innervation of the pancreas.
Assuntos
Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Pâncreas/embriologia , Pâncreas/inervação , Sistema Nervoso Parassimpático/embriologia , Análise de Variância , Animais , Diferenciação Celular/fisiologia , Movimento Celular/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/genética , Teste de Tolerância a Glucose , Imuno-Histoquímica , Camundongos , Camundongos Transgênicos , Microscopia de Fluorescência , Crista Neural/embriologia , Células-Tronco Neurais/fisiologia , Pâncreas/citologia , Reação em Cadeia da Polimerase em Tempo Real , beta-GalactosidaseRESUMO
BACKGROUND: Tourette syndrome is a disorder characterized by persistent motor and vocal tics, and frequently accompanied by the comorbidities attention deficit hyperactivity disorder and obsessive-compulsive disorder. Impaired synaptic neurotransmission has been implicated in its pathogenesis. Our aim was to investigate the association of 28 candidate genes, including genes related to synaptic neurotransmission and neurotrophic factors, with Tourette syndrome. METHODS: We genotyped 506 polymorphisms in a discovery cohort from the United States composed of 112 families and 47 unrelated singletons with Tourette syndrome (201 cases and 253 controls). Genes containing significant polymorphisms were imputed to fine-map the signal(s) to potential causal variants. Allelic analyses in Tourette syndrome cases were performed to check the role in attention deficit hyperactivity disorder and obsessive-compulsive disorder comorbidities. Target polymorphisms were further studied in a replication cohort from southern Spain composed of 37 families and three unrelated singletons (44 cases and 73 controls). RESULTS: The polymorphism rs3096140 in glial cell line-derived neurotrophic factor gene (GDNF) was significant in the discovery cohort after correction (P = 1.5 × 10(-4) ). No linkage disequilibrium was found between rs3096140 and other functional variants in the gene. We selected rs3096140 as target polymorphism, and the association was confirmed in the replication cohort (P = 0.01). No association with any comorbidity was found. CONCLUSIONS: As a conclusion, a common genetic variant in GDNF is associated with Tourette syndrome. A defect in the production of GDNF could compromise the survival of parvalbumin interneurons, thus altering the excitatory/inhibitory balance in the corticostriatal circuitry. Validation of this variant in other family cohorts is necessary.
Assuntos
Estudos de Associação Genética , Fator Neurotrófico Derivado de Linhagem de Célula Glial/genética , Transmissão Sináptica/genética , Síndrome de Tourette/genética , Adolescente , Adulto , Criança , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Polimorfismo Genético , Estados Unidos , Adulto JovemRESUMO
Vasodilation in response to low oxygen (O2) tension (hypoxic vasodilation) is an essential homeostatic response of systemic arteries that facilitates O2 supply to tissues according to demand. However, how blood vessels react to O2 deficiency is not well understood. A common belief is that arterial myocytes are O2-sensitive. Supporting this concept, it has been shown that the activity of myocyte L-type Ca2+channels, the main ion channels responsible for vascular contractility, is reversibly inhibited by hypoxia, although the underlying molecular mechanisms have remained elusive. Here, we show that genetic or pharmacological disruption of mitochondrial electron transport selectively abolishes O2 modulation of Ca2+ channels and hypoxic vasodilation. Mitochondria function as O2 sensors and effectors that signal myocyte Ca2+ channels due to constitutive Hif1α-mediated expression of specific electron transport subunit isoforms. These findings reveal the acute O2-sensing mechanisms of vascular cells and may guide new developments in vascular pharmacology.
Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia , Mitocôndrias , Oxigênio , Vasodilatação , Animais , Mitocôndrias/metabolismo , Oxigênio/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Camundongos , Transdução de Sinais , Masculino , Hipóxia/metabolismo , Camundongos Endogâmicos C57BL , Artérias/metabolismo , Canais de Cálcio Tipo L/metabolismo , Canais de Cálcio Tipo L/genética , Camundongos Knockout , Transporte de Elétrons , Canais de Cálcio/metabolismo , Canais de Cálcio/genéticaRESUMO
Primary mitochondrial diseases (PMDs) are associated with pediatric neurological disorders and are traditionally related to oxidative phosphorylation system (OXPHOS) defects in neurons. Interestingly, both PMD mouse models and patients with PMD show gliosis, and pharmacological depletion of microglia, the innate immune cells of the brain, ameliorates multiple symptoms in a mouse model. Given that microglia activation correlates with the expression of OXPHOS genes, we studied whether OXPHOS deficits in microglia may contribute to PMDs. We first observed that the metabolic rewiring associated with microglia stimulation in vitro (via IL-33 or TAU treatment) was partially changed by complex I (CI) inhibition (via rotenone treatment). In vivo, we generated a mouse model deficient for CI activity in microglia (MGcCI). MGcCI microglia showed metabolic rewiring and gradual transcriptional activation, which led to hypertrophy and dysfunction in juvenile (1-month-old) and adult (3-month-old) stages, respectively. MGcCI mice presented widespread reactive astrocytes, a decrease of synaptic markers accompanied by an increased number of parvalbumin neurons, a behavioral deficit characterized by prolonged periods of immobility, loss of weight and premature death that was partially rescued by pharmacologic depletion of microglia. Our data demonstrate that microglia development depends on mitochondrial CI and suggest a direct microglial contribution to PMDs.
Assuntos
Complexo I de Transporte de Elétrons , Microglia , Doenças Mitocondriais , Animais , Microglia/metabolismo , Camundongos , Complexo I de Transporte de Elétrons/metabolismo , Complexo I de Transporte de Elétrons/deficiência , Complexo I de Transporte de Elétrons/genética , Doenças Mitocondriais/metabolismo , Doenças Mitocondriais/etiologia , Fosforilação Oxidativa , Mitocôndrias/metabolismo , Neurônios/metabolismo , Neuroglia/metabolismo , Modelos Animais de Doenças , Astrócitos/metabolismo , Gliose/metabolismo , Gliose/patologia , Encéfalo/metabolismo , Encéfalo/patologiaRESUMO
Glial cell line-derived neurotrophic factor (GDNF) is absolutely required for survival of dopaminergic (DA) nigrostriatal neurons and protect them from toxic insults. Hence, it is a promising, albeit experimental, therapy for Parkinson's disease (PD). However, the source of striatal GDNF is not well known. GDNF seems to be normally synthesized in neurons, but numerous reports suggest GDNF production in glial cells, particularly in the injured brain. We have studied in detail striatal GDNF production in normal mouse and after damage of DA neurons with MPTP. Striatal GDNF mRNA was present in neonates but markedly increased during the first 2-3 postnatal weeks. Cellular identification of GDNF by unequivocal histochemical methods demonstrated that in normal or injured adult animals GDNF is expressed by striatal neurons and is not synthesized in significant amounts by astrocytes or microglial cells. GDNF mRNA expression was not higher in reactive astrocytes than in normal ones. Approximately 95% of identified neostriatal GDNF-expressing cells in normal and injured animals are parvalbumin-positive (PV+) interneurons, which only represent ~0.7% of all striatal neurons. The remaining 5% of GDNF+ cells are cholinergic and somatostatin+ interneurons. Surprisingly, medium spiny projection neurons (MSNs), the vast majority of striatal neurons that receive a strong DA innervation, do not express GDNF. PV+ interneurons constitute an oscillatory functional ensemble of electrically connected cells that control MSNs' firing. Production of GDNF in the PV+ neurons might be advantageous to supply synchronous activity-dependent release of GDNF in broad areas of the striatum. Stimulation of the GDNF-producing striatal PV+ ensemble in PD patients could have therapeutic effects.
Assuntos
Regulação da Expressão Gênica no Desenvolvimento/genética , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Interneurônios/metabolismo , Intoxicação por MPTP/patologia , Neostriado/citologia , Parvalbuminas/metabolismo , Análise de Variância , Animais , Animais Recém-Nascidos , Contagem de Células , Colina O-Acetiltransferase/metabolismo , Modelos Animais de Doenças , Fosfoproteína 32 Regulada por cAMP e Dopamina/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Fator Neurotrófico Derivado de Linhagem de Célula Glial/genética , Proteínas de Fluorescência Verde/genética , Interneurônios/efeitos dos fármacos , Intoxicação por MPTP/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Biológicos , Neostriado/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Vias Neurais/efeitos dos fármacos , Vias Neurais/lesões , Vias Neurais/metabolismo , RNA Mensageiro/metabolismo , Substância Negra/metabolismo , Fatores de TempoRESUMO
Oxygen-dependent prolyl hydroxylation of hypoxia-inducible factor (HIF) by a set of closely related prolyl hydroxylase domain enzymes (PHD1, 2 and 3) regulates a range of transcriptional responses to hypoxia. This raises important questions about the role of these oxygen-sensing enzymes in integrative physiology. We investigated the effect of both genetic deficiency and pharmacological inhibition on the change in ventilation in response to acute hypoxic stimulation in mice. Mice exposed to chronic hypoxia for 7 days manifest an exaggerated hypoxic ventilatory response (HVR) (10.8 ± 0.3 versus 4.1 ± 0.7 ml min(-1) g(-1) in controls; P < 0.01). HVR was similarly exaggerated in PHD2(+/-) animals compared to littermate controls (8.4 ± 0.7 versus 5.0 ± 0.8 ml min(-1) g(-1); P < 0.01). Carotid body volume increased (0.0025 ± 0.00017 in PHD2(+/-) animals versus 0.0015 ± 0.00019 mm(3) in controls; P < 0.01). In contrast, HVR in PHD1(-/-) and PHD3(-/-) mice was similar to littermate controls. Acute exposure to a small molecule PHD inhibitor (PHI) (2-(1-chloro-4-hydroxyisoquinoline-3-carboxamido) acetic acid) did not mimic the ventilatory response to hypoxia. Further, 7 day administration of the PHI induced only modest increases in HVR and carotid body cell proliferation, despite marked stimulation of erythropoiesis. This was in contrast with chronic hypoxia, which elicited both exaggerated HVR and cellular proliferation. The findings demonstrate that PHD enzymes modulate ventilatory sensitivity to hypoxia and identify PHD2 as the most important enzyme in this response. They also reveal differences between genetic inactivation of PHDs, responses to hypoxia and responses to a pharmacological inhibitor, demonstrating the need for caution in predicting the effects of therapeutic modulation of the HIF hydroxylase system on different physiological responses.
Assuntos
Corpo Carotídeo/patologia , Prolina Dioxigenases do Fator Induzível por Hipóxia/fisiologia , Hipóxia/fisiopatologia , Ventilação Pulmonar/fisiologia , Animais , Corpo Carotídeo/fisiopatologia , Hiperplasia/fisiopatologia , Fator 1 Induzível por Hipóxia/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos TransgênicosRESUMO
Early adaptive responses to hypoxia are essential for cell survival, but their nature and underlying mechanisms are poorly known. We have studied the post-transcriptional changes in the proteome of mammalian cells elicited by acute hypoxia and found that phosphorylation of eukaryotic elongation factor 2 (eEF2), a ribosomal translocase whose phosphorylation inhibits protein synthesis, is under the precise and reversible control of O(2) tension. Upon exposure to hypoxia, phosphorylation of eEF2 at Thr(56) occurred rapidly (<15 min) and resulted in modest translational arrest, a fundamental homeostatic response to hypoxia that spares ATP and thus facilitates cell survival. Acute inhibitory eEF2 phosphorylation occurred without ATP depletion or AMP kinase activation. Furthermore, eEF2 phosphorylation was mimicked by prolyl hydroxylase (PHD) inhibition with dimethyloxalylglycine or by selective PHD2 siRNA silencing but was independent of hypoxia-inducible factor α stabilization. Moreover, overexpression of PHD2 blocked hypoxic accumulation of phosphorylated eEF2. Therefore, our findings suggest that eEF2 phosphorylation status (and, as a consequence, translation rate) is controlled by PHD2 activity. They unravel a novel pathway for cell adaptation to hypoxia that could have pathophysiologic relevance in tissue ischemia and cancer.
Assuntos
Regulação Enzimológica da Expressão Gênica , Hipóxia/enzimologia , Hipóxia/genética , Fator 2 de Elongação de Peptídeos/genética , Fator 2 de Elongação de Peptídeos/metabolismo , Pró-Colágeno-Prolina Dioxigenase/metabolismo , Biossíntese de Proteínas , Trifosfato de Adenosina/metabolismo , Linhagem Celular , Humanos , Hipóxia/metabolismo , Prolina Dioxigenases do Fator Induzível por Hipóxia , Pró-Colágeno-Prolina Dioxigenase/genéticaRESUMO
BACKGROUND: The diagnosis of neuromuscular diseases is strongly based on the histological characterization of muscle biopsies. However, this morphological analysis is mostly a subjective process and difficult to quantify. We have tested if network science can provide a novel framework to extract useful information from muscle biopsies, developing a novel method that analyzes muscle samples in an objective, automated, fast and precise manner. METHODS: Our database consisted of 102 muscle biopsy images from 70 individuals (including controls, patients with neurogenic atrophies and patients with muscular dystrophies). We used this to develop a new method, Neuromuscular DIseases Computerized Image Analysis (NDICIA), that uses network science analysis to capture the defining signature of muscle biopsy images. NDICIA characterizes muscle tissues by representing each image as a network, with fibers serving as nodes and fiber contacts as links. RESULTS: After a 'training' phase with control and pathological biopsies, NDICIA was able to quantify the degree of pathology of each sample. We validated our method by comparing NDICIA quantification of the severity of muscular dystrophies with a pathologist's evaluation of the degree of pathology, resulting in a strong correlation (R = 0.900, P <0.00001). Importantly, our approach can be used to quantify new images without the need for prior 'training'. Therefore, we show that network science analysis captures the useful information contained in muscle biopsies, helping the diagnosis of muscular dystrophies and neurogenic atrophies. CONCLUSIONS: Our novel network analysis approach will serve as a valuable tool for assessing the etiology of muscular dystrophies or neurogenic atrophies, and has the potential to quantify treatment outcomes in preclinical and clinical trials.
Assuntos
Processamento de Imagem Assistida por Computador/métodos , Músculos/patologia , Atrofia Muscular/diagnóstico , Distrofias Musculares/diagnóstico , Redes Neurais de Computação , Patologia/métodos , Automação/métodos , Biópsia , HumanosRESUMO
Discovery of haemoglobin A expression outside of the erythroid cell lineage suggests that oxygen transport is the main, but not the unique, function of adult haemoglobin chains in mammals. The contribution of haemoglobin A to antioxidant defences has been proposed in the territories where it is expressed. Catecholaminergic cells rely on an active oxidative metabolism to accomplish their biological function, but are exposed to strong oxidative stress due to metabolism of catecholaminergic transmitters. We show in the present study that peripheral catecholaminegic cells express the α- and not the ß-haemoglobin A chains, and that α-haemoglobin expression could modulate the antioxidant capabilities of these cells. We also show that α-haemoglobin overexpression in PC12 cells leads to a selective increase of tyrosine hydroxylase synthesis and activity. This is achieved by means of a reorganization of antioxidant defences, decreasing cytoplasmic glutathione peroxidase and superoxide dismutase, and increasing mitochondrial peroxidase. Moreover, α-haemoglobin induces a decrease in lipogenesis and increase in lipid degradation, situations that help save NAD(P)H and favour supply of acetyl-CoA to the tricarboxylic acid cycle and production of reducing equivalents in the cell. All of these results point to a role for α-haemoglobin as a regulator of catecholaminergic cell metabolism required for phenotype acquisition and maintenance.
Assuntos
Glândulas Suprarrenais/metabolismo , Catecolaminas/metabolismo , Sistema Nervoso Simpático/metabolismo , alfa-Globinas/fisiologia , Glândulas Suprarrenais/inervação , Animais , Catecolaminas/análise , Catecolaminas/fisiologia , Células Cultivadas , Hemoglobinas/genética , Hemoglobinas/metabolismo , Hemoglobinas/fisiologia , Homeostase/fisiologia , Camundongos , Camundongos Transgênicos , Células NIH 3T3 , Células PC12 , Fenótipo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/fisiologia , Ratos , alfa-Globinas/genética , alfa-Globinas/metabolismoRESUMO
Vaccines against SARS-CoV-2 have been shown to be safe and effective but their protective efficacy against infection in the brain is yet unclear. Here, in the susceptible transgenic K18-hACE2 mouse model of severe coronavirus disease 2019 (COVID-19), we report a spatiotemporal description of SARS-CoV-2 infection and replication through the brain. SARS-CoV-2 brain replication occurs primarily in neurons, leading to neuronal loss, signs of glial activation and vascular damage in mice infected with SARS-CoV-2. One or two doses of a modified vaccinia virus Ankara (MVA) vector expressing the SARS-CoV-2 spike (S) protein (MVA-CoV2-S) conferred full protection against SARS-CoV-2 cerebral infection, preventing virus replication in all areas of the brain and its associated damage. This protection was maintained even after SARS-CoV-2 reinfection. These findings further support the use of MVA-CoV2-S as a promising vaccine candidate against SARS-CoV-2/COVID-19.
Assuntos
COVID-19 , SARS-CoV-2 , Camundongos , Animais , Humanos , Camundongos Transgênicos , Vacinas contra COVID-19 , EncéfaloRESUMO
GDNF is a potent neurotrophic factor that protects catecholaminergic neurons from toxic damage and induces fiber outgrowth. However, the actual role of endogenous GDNF in the normal adult brain is unknown, even though GDNF-based therapies are considered promising for neurodegenerative disorders. We have generated a conditional GDNF-null mouse to suppress GDNF expression in adulthood, hence avoiding the developmental compensatory modifications masking its true physiologic action. After Gdnf ablation, mice showed a progressive hypokinesia and a selective decrease of brain tyrosine hydroxylase (Th) mRNA, accompanied by pronounced catecholaminergic cell death, affecting most notably the locus coeruleus, which practically disappears; the substantia nigra; and the ventral tegmental area. These data unequivocally demonstrate that GDNF is indispensable for adult catecholaminergic neuron survival and also show that, under physiologic conditions, downregulation of a single trophic factor can produce massive neuronal death.
Assuntos
Encéfalo/citologia , Catecolaminas/metabolismo , Regulação da Expressão Gênica/genética , Fator Neurotrófico Derivado de Linhagem de Célula Glial/deficiência , Neurônios/metabolismo , Animais , Antineoplásicos Hormonais/toxicidade , Comportamento Animal/efeitos dos fármacos , Contagem de Células/métodos , Sobrevivência Celular/genética , Colina O-Acetiltransferase/metabolismo , Ensaio de Imunoadsorção Enzimática/métodos , Regulação da Expressão Gênica/efeitos dos fármacos , Fator Neurotrófico Derivado de Linhagem de Célula Glial/genética , Glutamato Descarboxilase/metabolismo , Hipocinesia/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Atividade Motora/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Fosfopiruvato Hidratase/metabolismo , Tamoxifeno/toxicidade , Fatores de Tempo , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
During starvation, mammalian brains can adapt their metabolism, switching from glucose to alternative peripheral fuel sources. In the Drosophila starved brain, memory formation is subject to adaptative plasticity, but whether this adaptive plasticity relies on metabolic adaptation remains unclear. Here we show that during starvation, neurons of the fly olfactory memory centre import and use ketone bodies (KBs) as an energy substrate to sustain aversive memory formation. We identify local providers within the brain, the cortex glia, that use their own lipid store to synthesize KBs before exporting them to neurons via monocarboxylate transporters. Finally, we show that the master energy sensor AMP-activated protein kinase regulates both lipid mobilization and KB export in cortex glia. Our data provide a general schema of the metabolic interactions within the brain to support memory when glucose is scarce.
Assuntos
Corpos Cetônicos , Inanição , Animais , Drosophila/metabolismo , Glucose/metabolismo , Corpos Cetônicos/metabolismo , Mamíferos/metabolismo , Neuroglia/metabolismo , Neurônios/metabolismo , Inanição/metabolismoRESUMO
Genetic Alzheimer's disease (AD) risk factors associate with reduced defensive amyloid ß plaque-associated microglia (AßAM), but the contribution of modifiable AD risk factors to microglial dysfunction is unknown. In AD mouse models, we observe concomitant activation of the hypoxia-inducible factor 1 (HIF1) pathway and transcription of mitochondrial-related genes in AßAM, and elongation of mitochondria, a cellular response to maintain aerobic respiration under low nutrient and oxygen conditions. Overactivation of HIF1 induces microglial quiescence in cellulo, with lower mitochondrial respiration and proliferation. In vivo, overstabilization of HIF1, either genetically or by exposure to systemic hypoxia, reduces AßAM clustering and proliferation and increases Aß neuropathology. In the human AD hippocampus, upregulation of HIF1α and HIF1 target genes correlates with reduced Aß plaque microglial coverage and an increase of Aß plaque-associated neuropathology. Thus, hypoxia (a modifiable AD risk factor) hijacks microglial mitochondrial metabolism and converges with genetic susceptibility to cause AD microglial dysfunction.
Assuntos
Doença de Alzheimer , Hipóxia Celular , Fator 1 Induzível por Hipóxia , Microglia , Mitocôndrias , Doença de Alzheimer/fisiopatologia , Mitocôndrias/metabolismo , Microglia/metabolismo , Fator 1 Induzível por Hipóxia/metabolismo , Peptídeos beta-Amiloides/metabolismo , Hipocampo , Fatores de Risco , Animais , Camundongos , Humanos , Linhagem Celular , Fosforilação OxidativaRESUMO
The human Alzheimer's disease (AD) brain accumulates angiogenic markers but paradoxically, the cerebral microvasculature is reduced around Aß plaques. Here we demonstrate that angiogenesis is started near Aß plaques in both AD mouse models and human AD samples. However, endothelial cells express the molecular signature of non-productive angiogenesis (NPA) and accumulate, around Aß plaques, a tip cell marker and IB4 reactive vascular anomalies with reduced NOTCH activity. Notably, NPA induction by endothelial loss of presenilin, whose mutations cause familial AD and which activity has been shown to decrease with age, produced a similar vascular phenotype in the absence of Aß pathology. We also show that Aß plaque-associated NPA locally disassembles blood vessels, leaving behind vascular scars, and that microglial phagocytosis contributes to the local loss of endothelial cells. These results define the role of NPA and microglia in local blood vessel disassembly and highlight the vascular component of presenilin loss of function in AD.
Assuntos
Doença de Alzheimer/genética , Peptídeos beta-Amiloides/genética , Vasos Sanguíneos/metabolismo , Encéfalo/metabolismo , Neovascularização Patológica/genética , Placa Amiloide/genética , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Vasos Sanguíneos/patologia , Encéfalo/irrigação sanguínea , Encéfalo/patologia , Modelos Animais de Doenças , Células Endoteliais/metabolismo , Feminino , Perfilação da Expressão Gênica/métodos , Humanos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Neovascularização Patológica/metabolismo , Placa Amiloide/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodosRESUMO
The asymmetrical positioning of neural structures on the left or right side of the brain in vertebrates and in invertebrates may be correlated with brain laterality, which is associated with cognitive skills. But until now this has not been illustrated experimentally. Here we describe an asymmetrically positioned brain structure in the fruitfly Drosophila and find that the small proportion of wild-type flies that have symmetrical brains with two such structures lack a normal long-term memory, although their short-term memory is intact. Our results indicate that brain asymmetry may be required for generating or retrieving long-term memory.
Assuntos
Encéfalo/anatomia & histologia , Encéfalo/fisiologia , Drosophila melanogaster/fisiologia , Memória/fisiologia , Animais , Encéfalo/anormalidades , Condicionamento Psicológico , Drosophila melanogaster/anatomia & histologia , Eletrochoque , Feminino , Lateralidade Funcional/fisiologia , Masculino , Memória de Curto Prazo/fisiologia , Odorantes , Olfato/fisiologia , Fatores de TempoRESUMO
Theta-Beta (T / B) ratio of the quantified electroencephalogram (EEGQ) in patients with attention deficit hyperactivity disorder (ADHD) constitutes a characteristic EEG variable of the primary disorder with an overall accuracy of 89%. The objective of this study was to measure the T/B ratio in a sample of patients with ADHD and the effects of the treatment with psychostimulants and non-psychostimulants on the T/B ratio. The sample consisted of 85 children between 6 and 18 years (68 males and 17 females) with the diagnosis of the inattentive and combined subtype of ADHD, according to the criteria of the DSM-V. An EEGQ was performed with measurement of the T/B ratio before and after 6 months of treatment with psychostimulant and non-psychostimulant drugs. Both groups were compared using the Wilcoxon signed range test for related samples. The results showed that 86% of the cases had a T/B ratio above the normal values for the age of them. The reduction in the T/B ratio was statistically significant in the group of patients treated with psychostimulants. The reduction of non-psychostimulants was not significant. In conclusion, we confirmed the high T/B ratio in patients with ADHD. Psychostimulant drugs decrease the elevated T/B ratio in patients with ADHD after 6 months of treatment.
El cociente Theta-Beta (T/B) del electroencefalograma cuantificado (EEGQ) de los pacientes con trastorno por déficit de atención e hiperactividad (TDAH) constituye una variable del EEG característica del trastorno primario con una precisión global del 89%. El objetivo de este estudio es medir el cociente T/B de una población de con TDAH y los efectos del tratamiento farmacológico con psicoestimulantes y no psicoestimulantes sobre el cociente T/B. La muestra estaba formada por 85 sujetos de entre 6 y los 18 años (68 niños y 17 niñas) con el diagnóstico de TDAH de subtipo inatento y combinado, según los criterios del DSM-V. Se les realizó un EEGQ con medición del cociente T/B antes y después de 6 meses de tratamiento con fármacos psicoestimulantes y no psicoestimulantes. Se compararon ambos grupos mediante la prueba de rangos con signo de Wilcoxon para muestras relacionadas. En el 86% de los casos el cociente T/B fue elevado respecto de los valores normales para la edad. La reducción en el cociente T/B fue significativa en el grupo tratado con psicoestimulantes aunque la reducción con los no psicoestimulantes no fue significativa. En conclusión, se confirma la elevación del cociente T/B en los pacientes con TDAH. Los fármacos psicoestimulantes disminuyen de forma significativa el cociente T/B elevado en los pacientes con TDAH tras 6 meses de tratamiento.