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1.
Nature ; 600(7890): 713-719, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34880502

RESUMEN

Cigarette smoking constitutes a leading global cause of morbidity and preventable death1, and most active smokers report a desire or recent attempt to quit2. Smoking-cessation-induced weight gain (SCWG; 4.5 kg reported to be gained on average per 6-12 months, >10 kg year-1 in 13% of those who stopped smoking3) constitutes a major obstacle to smoking abstinence4, even under stable5,6 or restricted7 caloric intake. Here we use a mouse model to demonstrate that smoking and cessation induce a dysbiotic state that is driven by an intestinal influx of cigarette-smoke-related metabolites. Microbiome depletion induced by treatment with antibiotics prevents SCWG. Conversely, fecal microbiome transplantation from mice previously exposed to cigarette smoke into germ-free mice naive to smoke exposure induces excessive weight gain across diets and mouse strains. Metabolically, microbiome-induced SCWG involves a concerted host and microbiome shunting of dietary choline to dimethylglycine driving increased gut energy harvest, coupled with the depletion of a cross-regulated weight-lowering metabolite, N-acetylglycine, and possibly by the effects of other differentially abundant cigarette-smoke-related metabolites. Dimethylglycine and N-acetylglycine may also modulate weight and associated adipose-tissue immunity under non-smoking conditions. Preliminary observations in a small cross-sectional human cohort support these findings, which calls for larger human trials to establish the relevance of this mechanism in active smokers. Collectively, we uncover a microbiome-dependent orchestration of SCWG that may be exploitable to improve smoking-cessation success and to correct metabolic perturbations even in non-smoking settings.


Asunto(s)
Microbioma Gastrointestinal , Cese del Hábito de Fumar , Aumento de Peso , Animales , Estudios Transversales , Disbiosis/etiología , Disbiosis/metabolismo , Disbiosis/patología , Ratones , Modelos Animales , Fumar/metabolismo , Fumar/patología
2.
Nature ; 572(7770): 474-480, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31330533

RESUMEN

Amyotrophic lateral sclerosis (ALS) is a complex neurodegenerative disorder, in which the clinical manifestations may be influenced by genetic and unknown environmental factors. Here we show that ALS-prone Sod1 transgenic (Sod1-Tg) mice have a pre-symptomatic, vivarium-dependent dysbiosis and altered metabolite configuration, coupled with an exacerbated disease under germ-free conditions or after treatment with broad-spectrum antibiotics. We correlate eleven distinct commensal bacteria at our vivarium with the severity of ALS in mice, and by their individual supplementation into antibiotic-treated Sod1-Tg mice we demonstrate that Akkermansia muciniphila (AM) ameliorates whereas Ruminococcus torques and Parabacteroides distasonis exacerbate the symptoms of ALS. Furthermore, Sod1-Tg mice that are administered AM are found to accumulate AM-associated nicotinamide in the central nervous system, and systemic supplementation of nicotinamide improves motor symptoms and gene expression patterns in the spinal cord of Sod1-Tg mice. In humans, we identify distinct microbiome and metabolite configurations-including reduced levels of nicotinamide systemically and in the cerebrospinal fluid-in a small preliminary study that compares patients with ALS with household controls. We suggest that environmentally driven microbiome-brain interactions may modulate ALS in mice, and we call for similar investigations in the human form of the disease.


Asunto(s)
Esclerosis Amiotrófica Lateral/microbiología , Esclerosis Amiotrófica Lateral/fisiopatología , Microbioma Gastrointestinal/fisiología , Niacinamida/metabolismo , Akkermansia , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/patología , Animales , Antibacterianos/farmacología , Modelos Animales de Enfermedad , Disbiosis , Femenino , Microbioma Gastrointestinal/efectos de los fármacos , Vida Libre de Gérmenes , Humanos , Longevidad , Masculino , Ratones , Ratones Transgénicos , Niacinamida/biosíntesis , Superóxido Dismutasa-1/genética , Superóxido Dismutasa-1/metabolismo , Tasa de Supervivencia , Simbiosis/efectos de los fármacos , Verrucomicrobia/metabolismo , Verrucomicrobia/fisiología
3.
Exp Physiol ; 109(1): 135-147, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-36951012

RESUMEN

By translating mechanical forces into molecular signals, proprioceptive neurons provide the CNS with information on muscle length and tension, which is necessary to control posture and movement. However, the identities of the molecular players that mediate proprioceptive sensing are largely unknown. Here, we confirm the expression of the mechanosensitive ion channel ASIC2 in proprioceptive sensory neurons. By combining in vivo proprioception-related functional tests with ex vivo electrophysiological analyses of muscle spindles, we showed that mice lacking Asic2 display impairments in muscle spindle responses to stretch and motor coordination tasks. Finally, analysis of skeletons of Asic2 loss-of-function mice revealed a specific effect on spinal alignment. Overall, we identify ASIC2 as a key component in proprioceptive sensing and a regulator of spine alignment.


Asunto(s)
Canales Iónicos Sensibles al Ácido , Propiocepción , Animales , Ratones , Canales Iónicos Sensibles al Ácido/metabolismo , Husos Musculares/fisiología , Propiocepción/fisiología , Células Receptoras Sensoriales/metabolismo
4.
Genes Dev ; 30(23): 2607-2622, 2016 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-28007784

RESUMEN

The Runx3 transcription factor is essential for development and diversification of the dorsal root ganglia (DRGs) TrkC sensory neurons. In Runx3-deficient mice, developing TrkC neurons fail to extend central and peripheral afferents, leading to cell death and disruption of the stretch reflex circuit, resulting in severe limb ataxia. Despite its central role, the mechanisms underlying the spatiotemporal expression specificities of Runx3 in TrkC neurons were largely unknown. Here we first defined the genomic transcription unit encompassing regulatory elements (REs) that mediate the tissue-specific expression of Runx3. Using transgenic mice expressing BAC reporters spanning the Runx3 locus, we discovered three REs-dubbed R1, R2, and R3-that cross-talk with promoter-2 (P2) to drive TrkC neuron-specific Runx3 transcription. Deletion of single or multiple elements either in the BAC transgenics or by CRISPR/Cas9-mediated endogenous ablation established the REs' ability to promote and/or repress Runx3 expression in developing sensory neurons. Our analysis reveals that an intricate combinatorial interplay among the three REs governs Runx3 expression in distinct subtypes of TrkC neurons while concomitantly extinguishing its expression in non-TrkC neurons. These findings provide insights into the mechanism regulating cell type-specific expression and subtype diversification of TrkC neurons in developing DRGs.


Asunto(s)
Subunidad alfa 3 del Factor de Unión al Sitio Principal/genética , Ganglios Espinales/embriología , Regulación del Desarrollo de la Expresión Génica/genética , Neuronas/metabolismo , Elementos Reguladores de la Transcripción/genética , Animales , Ataxia/genética , Sitios de Unión , Subunidad alfa 3 del Factor de Unión al Sitio Principal/metabolismo , Embrión de Mamíferos , Ganglios Espinales/citología , Eliminación de Gen , Locomoción/genética , Masculino , Ratones , Ratones Transgénicos , Neuronas/citología , Regiones Promotoras Genéticas/genética , Unión Proteica , Factores de Transcripción/metabolismo
5.
Am J Pathol ; 192(8): 1122-1135, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35659946

RESUMEN

Wound healing typically recruits the immune and vascular systems to restore tissue structure and function. However, injuries to the enthesis, a hypocellular and avascular tissue, often result in fibrotic scar formation and loss of mechanical properties, severely affecting musculoskeletal function and life quality. This raises questions about the healing capabilities of the enthesis. Herein, this study established an injury model to the Achilles entheses of neonatal mice to study the effectiveness of early-age enthesis healing. Histology and immunohistochemistry analyses revealed an atypical process that did not involve inflammation or angiogenesis. Instead, healing was mediated by secretion of collagen types I and II by resident cells, which formed a permanent hypocellular and avascular scar. Transmission electron microscopy showed that the cellular response to injury, including endoplasmic reticulum stress, autophagy, and cell death, varied between the tendon and cartilage ends of the enthesis. Single-molecule in situ hybridization, immunostaining, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assays verified these differences. Finally, gait analysis showed that these processes effectively restored function of the injured leg. These findings reveal a novel healing mechanism in neonatal entheses, whereby local extracellular matrix secretion by resident cells forms an acellular extracellular matrix deposit without inflammation, allowing gait restoration. These insights into the healing mechanism of a complex transitional tissue may lead to new therapeutic strategies for adult enthesis injuries.


Asunto(s)
Cicatriz , Cicatrización de Heridas , Animales , Matriz Extracelular , Inflamación , Ratones , Tendones , Cicatrización de Heridas/fisiología
6.
EMBO Rep ; 22(12): e53824, 2021 12 06.
Artículo en Inglés | MEDLINE | ID: mdl-34734666

RESUMEN

Academic Core Facilities are optimally situated to improve the quality of preclinical research by implementing quality control measures and offering these to their users.

8.
Int J Mol Sci ; 24(15)2023 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-37569901

RESUMEN

The major proteins involved in Alzheimer's disease (AD) are amyloid precursor protein (APP) and Tau. We demonstrate that APP1 (390-412) and Tau1 (19-34), linked together with either a flexible or a rigid peptide bridge, are able to inhibit, in vitro, the interaction between APP and Tau proteins. Furthermore, nasal administration of biotin-labelled Flex peptide for two weeks indicated the localization of the peptide around and close to plaques in the hippocampus area. In vivo studies in 5xFAD transgenic (Tg) mice, which exhibit plaque load and mild cognitive decline at four months of age, show that nasal administration of the flexible linked peptide reduced amyloid plaque burden. Additionally, nasal treatment with either flexible or rigid linked peptides prevented cognitive function deterioration. A significant treatment effect was achieved when either treatment was initiated at the age of three months, before severe cognitive deficiency is evident, or at five months, when such deficiency is already observed. The nasally treated mice demonstrated a cognitive ability not significantly different from the non-Tg littermate controls. Testing the effect of the flexible peptide by gavage feeding on the cognitive function of 5xFAD Tg mice demonstrated that feeding as well as nasal treatment significantly improves the cognitive ability of Tg mice compared to control PBS-treated mice.

9.
Eur J Neurosci ; 55(9-10): 2777-2793, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-34587653

RESUMEN

Chronic stress creates an allostatic overload that may lead to mood disorders such as anxiety and depression. Modern causes of chronic stress in humans are mostly social in nature, relating to work and relationship stress. Research into neural and molecular mechanisms of vulnerability and resilience following chronic social stress (CSS) is ongoing and uses animal models to discover efficient prevention strategies and treatments. To date, most CSS studies have neglected the female sex and used male-focused aggression-based animal models such as chronic social defeat stress (CSDS). Accumulating evidence on sex differences suggests differences in the stress response, the prevalence of stress-related illness and in response to treatment, indicating that researchers should expand CSS investigation to include female-focused protocols alongside the popular CSDS protocols. Here, we describe a novel female mouse model of CSS and a parallel modified male mouse model of CSDS in C57BL/6 mice. These new models enable the investigation of vulnerability, coping and downstream effectors mediating short-term and long-term consequences of CSS in both sexes. Our data demonstrate differential effects on male and female mice during, soon after, and many weeks after CSS. Female mice are more prone to body weight loss during CSS and hyperactive anxious behaviour following CSS. Both sexes show reduced social interaction, but only stressed male mice show long-term changes in emotional memory and neuroendocrine function. We further discuss future avenues of research using these models to investigate mechanisms pertaining to sensitivity to CSS and treatment response profiles, in a sex-appropriate manner.


Asunto(s)
Ansiedad , Estrés Psicológico , Animales , Modelos Animales de Enfermedad , Emociones , Femenino , Masculino , Ratones , Ratones Endogámicos C57BL , Conducta Social
10.
J Physiol ; 599(2): 521-545, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33124684

RESUMEN

KEY POINTS: G-protein inwardly rectifying K+ (GIRK) channels consist of four homologous subunits (GIRK1-4) and are essential regulators of electrical excitability in the nervous system. GIRK2-null mice have been widely investigated for their distinct behaviour and altered depotentiation following long-term potentiation (LTP), whereas GIRK1 mice are less well characterized. Here we utilize a novel knockin mouse strain in which the GIRK1 subunit is fluorescently tagged with yellow fluorescent protein (YFP-GIRK1) and the GIRK1-null mouse line to investigate the role of GIRK1 in neuronal processes such as spatial learning and memory, locomotion and depotentiation following LTP. Neurons dissected from YFP-GIRK1 mice had significantly reduced potassium currents and this mouse line phenotypically resembled GIRK1-null mice, making it a 'functional knockdown' model of GIRK1-containing channels. YFP-GIRK1 and GIRK1-null mice had increased locomotion, reduced spatial learning and memory and blunted depotentiation following LTP. ABSTRACT: GIRK channels are essential for the slow inhibition of electrical activity in the nervous system and heart rate regulation via the parasympathetic system. The implications of individual GIRK isoforms in specific physiological activities are based primarily on studies conducted with GIRK-null mouse lines. Here we utilize a novel knockin mouse line in which YFP was fused in-frame to the N-terminus of GIRK1 (YFP-GIRK1) to correlate GIRK1 spatial distribution with physiological activities. These mice, however, displayed spontaneous seizure-like activity and thus were investigated for the origin of such activity. We show that GIRK tetramers containing YFP-GIRK1 are correctly assembled and trafficked to the plasma membrane, but are functionally impaired. A battery of behavioural assays conducted on YFP-GIRK1 and GIRK1-null (GIRK1-/- ) mice revealed similar phenotypes, including impaired nociception, reduced anxiety and hyperactivity in an unfamiliar environment. However, YFP-GIRK1 mice exhibited increased home-cage locomotion while GIRK1-/- mice did not. In addition, we show that the GIRK1 subunit is essential for intact spatial learning and memory and synaptic plasticity in hippocampal brain slices. This study expands our knowledge regarding the role of GIRK1 in neuronal processes and underlines the importance of GIRK1-containing heterotetramers.


Asunto(s)
Canales de Potasio Rectificados Internamente Asociados a la Proteína G , Aprendizaje Espacial , Animales , Canales de Potasio Rectificados Internamente Asociados a la Proteína G/genética , Canales de Potasio Rectificados Internamente Asociados a la Proteína G/metabolismo , Hipocampo/metabolismo , Ratones , Plasticidad Neuronal , Neuronas/metabolismo
11.
Hum Genet ; 140(10): 1471-1485, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34417872

RESUMEN

Argininosuccinate lyase (ASL) is essential for the NO-dependent regulation of tyrosine hydroxylase (TH) and thus for catecholamine production. Using a conditional mouse model with loss of ASL in catecholamine neurons, we demonstrate that ASL is expressed in dopaminergic neurons in the substantia nigra pars compacta, including the ALDH1A1 + subpopulation that is pivotal for the pathogenesis of Parkinson disease (PD). Neuronal loss of ASL results in catecholamine deficiency, in accumulation and formation of tyrosine aggregates, in elevation of α-synuclein, and phenotypically in motor and cognitive deficits. NO supplementation rescues the formation of aggregates as well as the motor deficiencies. Our data point to a potential metabolic link between accumulations of tyrosine and seeding of pathological aggregates in neurons as initiators for the pathological processes involved in neurodegeneration. Hence, interventions in tyrosine metabolism via regulation of NO levels may be therapeutic beneficial for the treatment of catecholamine-related neurodegenerative disorders.


Asunto(s)
Familia de Aldehído Deshidrogenasa 1/genética , Familia de Aldehído Deshidrogenasa 1/metabolismo , Argininosuccinatoliasa/genética , Argininosuccinatoliasa/metabolismo , Neuronas Dopaminérgicas/metabolismo , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/metabolismo , Animales , Modelos Animales de Enfermedad , Humanos , Ratones , Fenotipo , Retinal-Deshidrogenasa/genética , Retinal-Deshidrogenasa/metabolismo
12.
Part Fibre Toxicol ; 17(1): 4, 2020 01 20.
Artículo en Inglés | MEDLINE | ID: mdl-31959190

RESUMEN

BACKGROUND: Carbonaceous aerosols emitted from indoor and outdoor biomass burning are major risk factors contributing to the global burden of disease. Wood tar aerosols, namely, tar ball particles, compose a substantial fraction of carbonaceous emissions, especially from biomass smoldering. However, their health-related impacts and toxicity are still not well known. This study investigated the toxicity of the water-soluble fraction of pyrolyzed wood tar aerosols in exposed mice and lung epithelial cells. RESULTS: Mice exposed to water-soluble wood tar aerosols showed increased inflammatory and oxidative stress responses. Bronchial epithelial cells exposed to the same water-soluble wood tar aerosols showed increased cell death with apoptotic characteristics. Alterations in oxidative status, including changes in reactive oxygen species (ROS) levels and reductions in the expression of antioxidant genes related to the transcription factor Nrf2, were observed and were confirmed by increased levels of MDA, a lipid peroxidation adduct. Damage to mitochondria was observed as an early event responsible for the aforementioned changes. CONCLUSIONS: The toxicity and health effect-related mechanisms of water-soluble wood tar were investigated for the first time in the context of biomass burning. Wood tar particles may account for major responses such as cell death, oxidative stress, supression of protection mechnaisms and mitochondrial damaged cause by expsoure to biomass burning aerosols.


Asunto(s)
Contaminantes Atmosféricos/toxicidad , Carbono/toxicidad , Pulmón/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Material Particulado/toxicidad , Madera/química , Aerosoles , Animales , Apoptosis/efectos de los fármacos , Biomasa , Líquido del Lavado Bronquioalveolar/química , Líquido del Lavado Bronquioalveolar/citología , Líquido del Lavado Bronquioalveolar/inmunología , Células Cultivadas , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Femenino , Humanos , Exposición por Inhalación/efectos adversos , Pulmón/inmunología , Pulmón/metabolismo , Ratones , Ratones Endogámicos C57BL , Especies Reactivas de Oxígeno/análisis , Especies Reactivas de Oxígeno/metabolismo
13.
Int J Mol Sci ; 21(9)2020 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-32380752

RESUMEN

The two major proteins involved in Alzheimer's disease (AD) are the amyloid precursor protein (APP) and Tau. Here, we demonstrate that these two proteins can bind to each other. Four possible peptides APP1 (390-412), APP2 (713-730), Tau1 (19-34) and Tau2 (331-348), were predicted to be involved in this interaction, with actual binding confirmed for APP1 and Tau1. In vivo studies were performed in an Alzheimer Disease animal model-APP double transgenic (Tg) 5xFAD-as well as in 5xFAD crossed with Tau transgenic 5xFADXTau (FT), which exhibit declined cognitive reduction at four months of age. Nasal administration of APP1 and Tau1 mixture, three times a week for four or five months, reduced amyloid plaque burden as well as the level of soluble Aß 1-42 in the brain. The treatment prevented the deterioration of cognitive functions when initiated at the age of three months, before cognitive deficiency was evident, and also at the age of six months, when such deficiencies are already observed, leading to a full regain of cognitive function.


Asunto(s)
Precursor de Proteína beta-Amiloide/química , Precursor de Proteína beta-Amiloide/metabolismo , Fragmentos de Péptidos/metabolismo , Proteínas tau/química , Proteínas tau/metabolismo , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/etiología , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/metabolismo , Animales , Biomarcadores , Cognición/efectos de los fármacos , Modelos Animales de Enfermedad , Técnica del Anticuerpo Fluorescente , Humanos , Aprendizaje por Laberinto/efectos de los fármacos , Ratones , Ratones Transgénicos , Fragmentos de Péptidos/química , Fragmentos de Péptidos/farmacología , Placa Amiloide/tratamiento farmacológico , Placa Amiloide/etiología , Placa Amiloide/patología , Unión Proteica
14.
J Neurosci ; 38(30): 6751-6765, 2018 07 25.
Artículo en Inglés | MEDLINE | ID: mdl-29934353

RESUMEN

Corticotropin-releasing factor (CRF) and its type 1 receptor (CRFR1) play an important role in the responses to stressful challenges. Despite the well established expression of CRFR1 in granular cells (GrCs), its role in procedural motor performance and memory formation remains elusive. To investigate the role of CRFR1 expression in cerebellar GrCs, we used a mouse model depleted of CRFR1 in these cells. We detected changes in the cellular learning mechanisms in GrCs depleted of CRFR1 in that they showed changes in intrinsic excitability and long-term synaptic plasticity. Analysis of cerebella transcriptome obtained from KO and control mice detected prominent alterations in the expression of calcium signaling pathways components. Moreover, male mice depleted of CRFR1 specifically in GrCs showed accelerated Pavlovian associative eye-blink conditioning, but no differences in baseline motor performance, locomotion, or fear and anxiety-related behaviors. Our findings shed light on the interplay between stress-related central mechanisms and cerebellar motor conditioning, highlighting the role of the CRF system in regulating particular forms of cerebellar learning.SIGNIFICANCE STATEMENT Although it is known that the corticotropin-releasing factor type 1 receptor (CRFR1) is highly expressed in the cerebellum, little attention has been given to its role in cerebellar functions in the behaving animal. Moreover, most of the attention was directed at the effect of CRF on Purkinje cells at the cellular level and, to this date, almost no data exist on the role of this stress-related receptor in other cerebellar structures. Here, we explored the behavioral and cellular effect of granular cell-specific ablation of CRFR1 We found a profound effect on learning both at the cellular and behavioral levels without an effect on baseline motor skills.


Asunto(s)
Cerebelo/metabolismo , Aprendizaje/fisiología , Neuronas/metabolismo , Receptores de Hormona Liberadora de Corticotropina/metabolismo , Animales , Conducta Animal/fisiología , Femenino , Masculino , Ratones , Ratones Noqueados
15.
PLoS Genet ; 11(8): e1005457, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26275053

RESUMEN

Following myonecrosis, muscle satellite cells proliferate, differentiate and fuse, creating new myofibers. The Runx1 transcription factor is not expressed in naïve developing muscle or in adult muscle tissue. However, it is highly expressed in muscles exposed to myopathic damage yet, the role of Runx1 in muscle regeneration is completely unknown. Our study of Runx1 function in the muscle's response to myonecrosis reveals that this transcription factor is activated and cooperates with the MyoD and AP-1/c-Jun transcription factors to drive the transcription program of muscle regeneration. Mice lacking dystrophin and muscle Runx1 (mdx-/Runx1f/f), exhibit impaired muscle regeneration leading to age-dependent muscle waste, gradual decrease in motor capabilities and a shortened lifespan. Runx1-deficient primary myoblasts are arrested at cell cycle G1 and consequently differentiate. Such premature differentiation disrupts the myoblasts' normal proliferation/differentiation balance, reduces the number and size of regenerating myofibers and impairs muscle regeneration. Our combined Runx1-dependent gene expression, ChIP-seq, ATAC-seq and histone H3K4me1/H3K27ac modification analyses revealed a subset of Runx1-regulated genes that are co-occupied by MyoD and c-Jun in mdx-/Runx1f/f muscle. The data provide unique insights into the transcriptional program driving muscle regeneration and implicate Runx1 as an important participant in the pathology of muscle wasting diseases.


Asunto(s)
Subunidad alfa 2 del Factor de Unión al Sitio Principal/fisiología , Músculo Esquelético/fisiología , Mioblastos/fisiología , Regeneración , Animales , Secuencia de Bases , Sitios de Unión , Diferenciación Celular , Proliferación Celular , Células Cultivadas , Secuencia de Consenso , Femenino , Expresión Génica , Regulación de la Expresión Génica , Genes jun , Masculino , Ratones Endogámicos mdx , Proteína MioD/metabolismo
16.
J Neurosci ; 36(3): 730-40, 2016 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-26791204

RESUMEN

Recently, it has been suggested that alterations in DNA methylation mediate the molecular changes and psychopathologies that can occur following trauma. Despite the abundance of DNA methyltransferases (Dnmts) in the brain, which are responsible for catalyzing DNA methylation, their roles in behavioral regulation and in response to stressful challenges remain poorly understood. Here, we demonstrate that adult mice which underwent chronic social defeat stress (CSDS) displayed elevated anxiety-like behavior that was accompanied by a reduction in medial prefrontal cortex (mPFC)-DNA methyltransferase 3a (Dnmt3a) mRNA levels and a subsequent decrease in mPFC-global DNA methylation. To explore the role of mPFC-Dnmt3a in mediating the behavioral responses to stressful challenges we established lentiviral-based mouse models that express lower (knockdown) or higher (overexpression) levels of Dnmt3a specifically within the mPFC. Nonstressed mice injected with knockdown Dnmt3a lentiviruses specifically into the mPFC displayed the same anxiogenic phenotype as the CSDS mice, whereas overexpression of Dnmt3a induced an opposite, anxiolytic, effect in wild-type mice. In addition, overexpression of Dnmt3a in the mPFC of CSDS mice attenuated stress-induced anxiety. Our results indicate a central role for mPFC-Dnmt3a as a mediator of stress-induced anxiety. Significance statement: DNA methylation is suggested to mediate the molecular mechanisms linking environmental challenges, such as chronic stress or trauma, to increased susceptibility to psychopathologies. Here, we show that chronic stress-induced increase in anxiety-like behavior is accompanied by a reduction in DNA methyltransferase 3a (Dnmt3a) mRNA levels and global DNA methylation in the medial prefrontal cortex (mPFC). Overexpression or knockdown of mPFC-Dnmt3a levels induces decrease or increase in anxiety-like behavior, respectively. In addition, overexpression of Dnmt3a in the mPFC of chronic stressed mice attenuated stress-induced anxiety. We suggest that mPFC-Dnmt3a levels mediates anxiety-like behavior, which may be a primary molecular link between chronic stress and the development of anxiety disorders, including post-traumatic stress disorder.


Asunto(s)
Ansiedad/metabolismo , ADN (Citosina-5-)-Metiltransferasas/biosíntesis , Corteza Prefrontal/metabolismo , Factores de Edad , Animales , Ansiedad/etiología , Ansiedad/psicología , ADN Metiltransferasa 3A , Técnicas de Silenciamiento del Gen/métodos , Células HEK293 , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Estrés Psicológico/complicaciones , Estrés Psicológico/metabolismo , Estrés Psicológico/psicología
17.
Mol Cell Neurosci ; 70: 42-53, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26647347

RESUMEN

Genome-wide association studies and copy number variation analyses have linked contactin associated protein 2 (Caspr2, gene name Cntnap2) with autism spectrum disorder (ASD). In line with these findings, mice lacking Caspr2 (Cntnap2(-/-)) were shown to have core autism-like deficits including abnormal social behavior and communication, and behavior inflexibility. However the role of Caspr2 in ASD pathogenicity remains unclear. Here we have generated a new Caspr2:tau-LacZ knock-in reporter line (Cntnap2(tlacz/tlacz)), which enabled us to monitor the neuronal circuits in the brain expressing Caspr2. We show that Caspr2 is expressed in many brain regions and produced a comprehensive report of Caspr2 expression. Moreover, we found that Caspr2 marks all sensory modalities: it is expressed in distinct brain regions involved in different sensory processings and is present in all primary sensory organs. Olfaction-based behavioral tests revealed that mice lacking Caspr2 exhibit abnormal response to sensory stimuli and lack preference for novel odors. These results suggest that loss of Caspr2 throughout the sensory system may contribute to the sensory manifestations frequently observed in ASD.


Asunto(s)
Encéfalo/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Neuronas/metabolismo , Percepción Olfatoria/fisiología , Animales , Trastorno del Espectro Autista/genética , Trastorno del Espectro Autista/metabolismo , Proteínas de la Membrana/genética , Ratones , Ratones Transgénicos , Proteínas del Tejido Nervioso/genética , Odorantes
18.
Proc Natl Acad Sci U S A ; 109(7): 2642-7, 2012 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-22308328

RESUMEN

G protein-activated inwardly rectifying K+ channels (GIRK) generate slow inhibitory postsynaptic potentials in the brain via G(i/o) protein-coupled receptors. GIRK2, a GIRK subunit, is widely abundant in the brain and has been implicated in various functions and pathologies, such as learning and memory, reward, motor coordination, and Down syndrome. Down syndrome, the most prevalent cause of mental retardation, results from the presence of an extra maternal chromosome 21 (trisomy 21), which comprises the Kcnj6 gene (GIRK2). The present study examined the behaviors and cellular physiology properties in mice harboring a single trisomy of the Kcnj6 gene. Kcnj6 triploid mice exhibit deficits in hippocampal-dependent learning and memory, altered responses to rewards, hampered depotentiation, a form of excitatory synaptic plasticity, and have accentuated long-term synaptic depression. Collectively the findings suggest that triplication of Kcnj6 gene may play an active role in some of the abnormal neurological phenotypes found in Down syndrome.


Asunto(s)
Cognición , Canales de Potasio Rectificados Internamente Asociados a la Proteína G/fisiología , Plasticidad Neuronal , Recompensa , Trisomía , Animales , Ritmo Circadiano , Canales de Potasio Rectificados Internamente Asociados a la Proteína G/genética , Hipocampo/fisiología , Ratones
19.
Glia ; 62(4): 649-65, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24481644

RESUMEN

Myelinogenesis in the mammal nervous system occurs predominantly postnatally. Glatiramer acetate (GA), a drug for the treatment for multiple sclerosis (MS), has been shown to induce immunomodulation and neuroprotection in the inflamed CNS in MS and in experimental autoimmune encephalomyelitis (EAE). Here we investigated whether GA can affect myelinogenesis and oligodendrogenesis in the developing nervous system under nonpathological conditions. Towards this end we studied myelination in mice injected daily by GA, at postnatal Days 7-21. Immunohistological and ultrastructural analyses revealed significant elevation in the number of myelinated axons as well as in the thickness of the myelin encircling them and their resulting g-ratios, in spinal cords of GA-injected mice compared with their PBS-injected littermates, at postnatal Day 14. Elevation in myelinated axons was detected also in the peripheral ventral roots of the motor nerves. GA induced also an increase in axonal diameter, implying an effect on the overall development of the nervous system. A prominent elevation in the amount of progenitor oligodendrocytes and their BrdU incorporation, as well as in mature oligodendrocytes indicated that the effect of GA is linked to increased proliferation and differentiation along the oligodendroglial maturation cascade. In addition, elevation in insulin-like growth factor (IGF-1) and brain-derived neurotrophic factor (BDNF) was found in the white matter of the GA-injected mice. Furthermore, a functional advantage in rotating rod test was exhibited by GA-injected mice over their littermates at postnatal Day 21. These cumulative findings corroborate the beneficial effect of GA on oligodendrogenesis and myelination.


Asunto(s)
Encéfalo , Regulación del Desarrollo de la Expresión Génica , Inmunosupresores , Vaina de Mielina , Oligodendroglía , Péptidos , Animales , Ratones , Animales Recién Nacidos , Antígenos/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Encéfalo/efectos de los fármacos , Encéfalo/crecimiento & desarrollo , Encéfalo/ultraestructura , Proliferación Celular/efectos de los fármacos , Conducta Exploratoria/efectos de los fármacos , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Acetato de Glatiramer , Inmunosupresores/farmacología , Factor I del Crecimiento Similar a la Insulina/metabolismo , Ratones Endogámicos C57BL , Microscopía Electrónica de Transmisión , Actividad Motora/efectos de los fármacos , Vaina de Mielina/efectos de los fármacos , Vaina de Mielina/fisiología , Vaina de Mielina/ultraestructura , Proteínas del Tejido Nervioso/metabolismo , Factor de Transcripción 2 de los Oligodendrocitos , Oligodendroglía/efectos de los fármacos , Oligodendroglía/fisiología , Oligodendroglía/ultraestructura , Organogénesis/efectos de los fármacos , Péptidos/farmacología , Proteoglicanos/metabolismo , Factores de Tiempo , Esclerosis Múltiple
20.
Lab Anim (NY) ; 53(3): 67-79, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38438748

RESUMEN

Although biomedical research is experiencing a data explosion, the accumulation of vast quantities of data alone does not guarantee a primary objective for science: building upon existing knowledge. Data collected that lack appropriate metadata cannot be fully interrogated or integrated into new research projects, leading to wasted resources and missed opportunities for data repurposing. This issue is particularly acute for research using animals, where concerns regarding data reproducibility and ensuring animal welfare are paramount. Here, to address this problem, we propose a minimal metadata set (MNMS) designed to enable the repurposing of in vivo data. MNMS aligns with an existing validated guideline for reporting in vivo data (ARRIVE 2.0) and contributes to making in vivo data FAIR-compliant. Scenarios where MNMS should be implemented in diverse research environments are presented, highlighting opportunities and challenges for data repurposing at different scales. We conclude with a 'call for action' to key stakeholders in biomedical research to adopt and apply MNMS to accelerate both the advancement of knowledge and the betterment of animal welfare.


Asunto(s)
Investigación Biomédica , Metadatos , Animales , Reproducibilidad de los Resultados , Bienestar del Animal
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