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1.
Glia ; 69(8): 1852-1881, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33634529

RESUMEN

Astrocytes regulate synaptic communication and are essential for proper brain functioning. In Alzheimer's disease (AD) astrocytes become reactive, which is characterized by an increased expression of intermediate filament proteins and cellular hypertrophy. Reactive astrocytes are found in close association with amyloid-beta (Aß) deposits. Synaptic communication and neuronal network function could be directly modulated by reactive astrocytes, potentially contributing to cognitive decline in AD. In this review, we focus on reactive astrocytes as treatment targets in AD in the APPswePS1dE9 AD mouse model, a widely used model to study amyloidosis and gliosis. We first give an overview of the model; that is, how it was generated, which cells express the transgenes, and the effect of its genetic background on Aß pathology. Subsequently, to determine whether modifying reactive astrocytes in AD could influence pathogenesis and cognition, we review studies using this mouse model in which interventions were directly targeted at reactive astrocytes or had an indirect effect on reactive astrocytes. Overall, studies specifically targeting astrocytes to reduce astrogliosis showed beneficial effects on cognition, which indicates that targeting astrocytes should be included in developing novel therapies for AD.


Asunto(s)
Enfermedad de Alzheimer , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/metabolismo , Animales , Astrocitos/metabolismo , Modelos Animales de Enfermedad , Gliosis/patología , Ratones , Ratones Transgénicos
2.
J Exp Biol ; 222(Pt 17)2019 09 03.
Artículo en Inglés | MEDLINE | ID: mdl-31371403

RESUMEN

The timing of breeding is under selection in wild populations as a result of climate change, and understanding the underlying physiological processes mediating this timing provides insight into the potential rate of adaptation. Current knowledge on this variation in physiology is, however, mostly limited to males. We assessed whether individual differences in the timing of breeding in females are reflected in differences in candidate gene expression and, if so, whether these differences occur in the upstream (hypothalamus) or downstream (ovary and liver) parts of the neuroendocrine system. We used 72 female great tits from two generations of lines artificially selected for early and late egg laying, which were housed in climate-controlled aviaries and went through two breeding cycles within 1 year. In the first breeding season we obtained individual egg-laying dates, while in the second breeding season, using the same individuals, we sampled several tissues at three time points based on the timing of the first breeding attempt. For each tissue, mRNA expression levels were measured using qPCR for a set of candidate genes associated with the timing of reproduction and subsequently analysed for differences between generations, time points and individual timing of breeding. We found differences in gene expression between generations in all tissues, with the most pronounced differences in the hypothalamus. Differences between time points, and early- and late-laying females, were found exclusively in the ovary and liver. Altogether, we show that fine-tuning of the seasonal timing of breeding, and thereby the opportunity for adaptation in the neuroendocrine system, is regulated mostly downstream in the neuro-endocrine system.


Asunto(s)
Expresión Génica , Comportamiento de Nidificación , Reproducción , Pájaros Cantores/fisiología , Animales , Variación Biológica Individual , Femenino , Hipotálamo/fisiología , Hígado/fisiología , Ovario/fisiología , Estaciones del Año , Pájaros Cantores/genética
3.
Cereb Cortex ; 28(4): 1183-1194, 2018 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-28184425

RESUMEN

The formation, plasticity and maintenance of synaptic connections is regulated by molecular and electrical signals. ß-Catenin is an important protein in these events and regulates cadherin-mediated cell adhesion and the recruitment of pre- and postsynaptic proteins in an activity-dependent fashion. Mutations in the ß-catenin gene can cause cognitive disability and autism, with life-long consequences. Understanding its synaptic function may thus be relevant for the treatment of these disorders. So far, ß-catenin's function has been studied predominantly in cell culture and during development but knowledge on its function in adulthood is limited. Here, we show that ablating ß-catenin in excitatory neurons of the adult visual cortex does not cause the same synaptic deficits previously observed during development. Instead, it reduces NMDA-receptor currents and impairs visual processing. We conclude that ß-catenin remains important for adult cortical function but through different mechanisms than during development.


Asunto(s)
Receptores de N-Metil-D-Aspartato/metabolismo , Corteza Visual/metabolismo , beta Catenina/metabolismo , 2-Amino-5-fosfonovalerato/análogos & derivados , 2-Amino-5-fosfonovalerato/farmacología , Animales , Estimulación Eléctrica , Antagonistas de Aminoácidos Excitadores/farmacología , Regulación de la Expresión Génica/genética , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , N-Metilaspartato/metabolismo , Parvalbúminas/metabolismo , Técnicas de Placa-Clamp , ARN Mensajero/metabolismo , Privación Sensorial , Potenciales Sinápticos/efectos de los fármacos , Potenciales Sinápticos/genética , Corteza Visual/efectos de los fármacos , Sustancia Blanca/efectos de los fármacos , Sustancia Blanca/fisiología , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiónico/metabolismo , beta Catenina/genética
4.
Biochim Biophys Acta ; 1862(10): 1847-60, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27425031

RESUMEN

Amyloid plaques in Alzheimer's disease (AD) mice are surrounded by activated microglia. The functional role of microglia activation in AD is not well understood; both detrimental and beneficial effects on AD progression have been reported. Here we show that the population of activated microglia in the cortex of the APPswe/PS1dE9 mouse AD model is divided into a CD11c-positive and a CD11c-negative subpopulation. Cd11c transcript levels and number of CD11c-positive microglia increase sharply when plaques start to occur and both parameters continue to rise in parallel with the age-related increasing plaque load. CD11c cells are localized near plaques at all stages of the disease development and constitute 23% of all activated microglia. No differences between these two populations were found in terms of proliferation, immunostaining intensity of Iba1, MHC class II, CD45, or immunoproteasome subunit LMP7/ß5i. Comparison of the transcriptome of isolated CD11c-positive and CD11c-negative microglia from the cortex of aged APPswe/PS1dE9 with WT microglia showed that gene expression changes had a similar general pattern. However, a differential expression was found for genes involved in immune signaling (Il6, S100a8/Mrp8, S100a9/Mrp14, Spp1, Igf1), lysosome activation, and carbohydrate- and cholesterol/lipid-metabolism (Apoe). In addition, the increased expression of Gpnmb/DC-HIL, Tm7sf4/DC-STAMP, and Gp49a/Lilrb4, suggests a suppressive/tolerizing influence of CD11c cells. We show that amyloid plaques in the APP/PS1 model are associated with two distinct populations of activated microglia: CD11c-positive and CD11c-negative cells. Our findings imply that CD11c-positive microglia can potentially counteract amyloid deposition via increased Aß-uptake and degradation, and by containing the inflammatory response.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Antígeno CD11c/metabolismo , Regulación de la Expresión Génica , Microglía/metabolismo , Proteínas del Tejido Nervioso/biosíntesis , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/genética , Animales , Antígeno CD11c/genética , Modelos Animales de Enfermedad , Perfilación de la Expresión Génica , Ratones , Ratones Transgénicos , Microglía/patología , Proteínas del Tejido Nervioso/genética
5.
Glia ; 65(1): 50-61, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27615381

RESUMEN

Huntington's disease (HD) is an autosomal dominant inherited neurodegenerative disorder that is caused by a CAG expansion in the Huntingtin (HTT) gene, leading to HTT inclusion formation in the brain. The mutant huntingtin protein (mHTT) is ubiquitously expressed and therefore nuclear inclusions could be present in all brain cells. The effects of nuclear inclusion formation have been mainly studied in neurons, while the effect on glia has been comparatively disregarded. Astrocytes, microglia, and oligodendrocytes are glial cells that are essential for normal brain function and are implicated in several neurological diseases. Here we examined the number of nuclear mHTT inclusions in both neurons and various types of glia in the two brain areas that are the most affected in HD, frontal cortex, and striatum. We compared nuclear mHTT inclusion body formation in three HD mouse models that express either full-length HTT or an N-terminal exon1 fragment of mHTT, and we observed nuclear inclusions in neurons, astrocytes, oligodendrocytes, and microglia. When studying the frequency of cells with nuclear inclusions in mice, we found that half of the population of neurons contained nuclear inclusions at the disease end stage, whereas the proportion of GFAP-positive astrocytes and oligodendrocytes having a nuclear inclusion was much lower, while microglia hardly showed any nuclear inclusions. Nuclear inclusions were also present in neurons and all studied glial cell types in human patient material. This is the first report to compare nuclear mHTT inclusions in glia and neurons in different HD mouse models and HD patient brains. GLIA 2016;65:50-61.


Asunto(s)
Proteína Huntingtina/metabolismo , Enfermedad de Huntington/genética , Neuroglía/metabolismo , Neuronas/metabolismo , Animales , Astrocitos/metabolismo , Encéfalo/citología , Encéfalo/metabolismo , Modelos Animales de Enfermedad , Femenino , Enfermedad de Huntington/metabolismo , Masculino , Ratones Transgénicos , Proteínas del Tejido Nervioso/metabolismo , Proteínas Nucleares/metabolismo
6.
Glia ; 63(6): 1036-56, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25731615

RESUMEN

Reactive astrocytes with an increased expression of intermediate filament (IF) proteins Glial Fibrillary Acidic Protein (GFAP) and Vimentin (VIM) surround amyloid plaques in Alzheimer's disease (AD). The functional consequences of this upregulation are unclear. To identify molecular pathways coupled to IF regulation in reactive astrocytes, and to study the interaction with microglia, we examined WT and APPswe/PS1dE9 (AD) mice lacking either GFAP, or both VIM and GFAP, and determined the transcriptome of cortical astrocytes and microglia from 15- to 18-month-old mice. Genes involved in lysosomal degradation (including several cathepsins) and in inflammatory response (including Cxcl5, Tlr6, Tnf, Il1b) exhibited a higher AD-induced increase when GFAP, or VIM and GFAP, were absent. The expression of Aqp4 and Gja1 displayed the same pattern. The downregulation of neuronal support genes in astrocytes from AD mice was absent in GFAP/VIM null mice. In contrast, the absence of IFs did not affect the transcriptional alterations induced by AD in microglia, nor was the cortical plaque load altered. Visualizing astrocyte morphology in GFAP-eGFP mice showed no clear structural differences in GFAP/VIM null mice, but did show diminished interaction of astrocyte processes with plaques. Microglial proliferation increased similarly in all AD groups. In conclusion, absence of GFAP, or both GFAP and VIM, alters AD-induced changes in gene expression profile of astrocytes, showing a compensation of the decrease of neuronal support genes and a trend for a slightly higher inflammatory expression profile. However, this has no consequences for the development of plaque load, microglial proliferation, or microglial activation.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Astrocitos/metabolismo , Proteína Ácida Fibrilar de la Glía/deficiencia , Microglía/metabolismo , Vimentina/deficiencia , Anciano , Enfermedad de Alzheimer/patología , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animales , Astrocitos/patología , Encéfalo/metabolismo , Encéfalo/patología , Proliferación Celular/fisiología , Quimiocina CXCL5/metabolismo , Modelos Animales de Enfermedad , Expresión Génica/fisiología , Proteína Ácida Fibrilar de la Glía/genética , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Humanos , Masculino , Ratones de la Cepa 129 , Ratones Endogámicos C57BL , Ratones Transgénicos , Microglía/patología , Presenilina-1/genética , Presenilina-1/metabolismo , Vimentina/genética
7.
Biomarkers ; 20(3): 196-201, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26220620

RESUMEN

ADAM10 is a potential biomarker for Alzheimer's disease (AD). ADAM10 protein levels are reduced in platelets of AD patients. The aim was to verify the total blood and platelet ADAM10 gene expression in AD patients and to compare with mild cognitive impairment (MCI) and healthy subjects. No significant differences in ADAM10 gene expression were observed. Therefore, the decrease of ADAM10 protein in platelets of AD patients is not caused by a reduction in ADAM10 mRNA. Further studies must be performed to investigate other pathways in the down regulation of ADAM10 protein.


Asunto(s)
Proteínas ADAM/genética , Enfermedad de Alzheimer/sangre , Secretasas de la Proteína Precursora del Amiloide/genética , Disfunción Cognitiva/sangre , Proteínas de la Membrana/genética , ARN Mensajero/genética , Proteínas ADAM/sangre , Proteína ADAM10 , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/fisiopatología , Secretasas de la Proteína Precursora del Amiloide/sangre , Biomarcadores/sangre , Plaquetas/metabolismo , Plaquetas/patología , Estudios de Casos y Controles , Disfunción Cognitiva/genética , Disfunción Cognitiva/fisiopatología , Femenino , Expresión Génica , Humanos , Masculino , Proteínas de la Membrana/sangre , Persona de Mediana Edad , Pruebas Neuropsicológicas , ARN Mensajero/sangre
8.
J Neurochem ; 130(6): 805-15, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24749759

RESUMEN

Enteric glial cells (EGCs) are in many respects similar to astrocytes of the central nervous system and express similar proteins including glial fibrillary acidic protein (GFAP). Changes in GFAP expression and/or phosphorylation have been reported during brain damage or central nervous system degeneration. As in Parkinson's disease (PD) the enteric neurons accumulate α-synuclein, and thus are showing PD-specific pathological features, we undertook the present survey to study whether the enteric glia in PD become reactive by assessing the expression and phosphorylation levels of GFAP in colonic biopsies. Twenty-four PD, six progressive supranuclear palsy (PSP), six multiple system atrophy (MSA) patients, and 21 age-matched healthy controls were included. The expression levels and the phosphorylation state of GFAP were analyzed in colonic biopsies by western blot. Additional experiments were performed using real-time PCR for a more precise analysis of the GFAP isoforms expressed by EGCs. We showed that GFAPκ was the main isoform expressed in EGCs. As compared to control subjects, patients with PD, but not PSP and MSA, had significant higher GFAP expression levels in their colonic biopsies. The phosphorylation level of GFAP at serine 13 was significantly lower in PD patients compared to control subjects. By contrast, no change in GFAP phosphorylation was observed between PSP, MSA and controls. Our findings provide evidence that enteric glial reaction occurs in PD and further reinforce the role of the enteric nervous system in the initiation and/or the progression of the disease. We showed that GFAP is over-expressed and hypophosphorylated in the enteric glial cells (EGCs) of Parkinson's disease (PD) patients as compared to healthy subjects and patients with atypical parkinsonism (MSA, multiple system atrophy and PSP, progressive supranuclear palsy). Our findings provide evidence that enteric glial reaction occurs in PD but not in PSP and MSA and further reinforce the role of the enteric nervous system in the pathophysiology of PD.


Asunto(s)
Proteína Ácida Fibrilar de la Glía/biosíntesis , Enfermedad de Parkinson/metabolismo , Adulto , Anciano , Secuencia de Aminoácidos , Animales , Western Blotting , Química Encefálica/efectos de los fármacos , Línea Celular , Colon/metabolismo , Femenino , Proteína Ácida Fibrilar de la Glía/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Neuroglía/metabolismo , Fosforilación , Procesamiento Proteico-Postraduccional/fisiología , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Ratas , Reacción en Cadena en Tiempo Real de la Polimerasa , Serina/metabolismo
9.
Brain ; 136(Pt 5): 1415-31, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23604491

RESUMEN

The proteasome is the major protein degradation system within the cell, comprised of different proteolytic subunits; amyloid-ß is thought to impair its activity in Alzheimer's disease. Neuroinflammation is a prominent hallmark of Alzheimer's disease, which may implicate an activation of the immunoproteasome, a specific proteasome variant induced by immune signalling that holds slightly different proteolytic properties than the constitutive proteasome. Using a novel cell-permeable proteasome activity probe, we found that amyloid-ß enhances proteasome activity in glial and neuronal cultures. Additionally, using a subunit-specific proteasome activity assay we showed that in the cortex of the APPswePS1dE9 plaque pathology mouse model, immunoproteasome activities were strongly increased together with increased messenger RNA and protein expression in reactive glia surrounding plaques. Importantly, this elevated activity was confirmed in human post-mortem tissue from donors with Alzheimer's disease. These findings are in contrast with earlier studies, which reported impairment of proteasome activity in human Alzheimer's disease tissue and mouse models. Targeting the increased immunoproteasome activity with a specific inhibitor resulted in a decreased expression of inflammatory markers in ex vivo microglia. This may serve as a potential novel approach to modulate sustained neuroinflammation and glial dysfunction associated with Alzheimer's disease.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Neuroglía/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/inmunología , Animales , Células Cultivadas , Activación Enzimática/inmunología , Femenino , Humanos , Masculino , Ratones , Ratones Transgénicos , Persona de Mediana Edad , Neuroglía/inmunología , Células Tumorales Cultivadas
10.
Glia ; 60(4): 615-29, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22262260

RESUMEN

Plaque deposition in Alzheimer's disease (AD) is known to decrease proliferation in neurogenic niches in AD mouse models, but the effects on cell proliferation and differentiation in other brain areas have not been studied in detail. We analyzed cell proliferation in the cortex of wild type (WT) and APPswePS1dE9 transgenic (AD) mice at different ages. Mice were studied shortly after the last BrdU injection (BrdU[ST]). In AD mice, the number of proliferating cells increased fourfold, coinciding with plaque appearance and its associated reactive gliosis and activation of microglia. An increase in the number of BrdU[ST]-cells expressing markers for activated microglia is underlying the enhanced proliferation. Cortical reactive astrocytes did not become proliferative since BrdU[ST]-cells were negative for different astrocyte-specific markers. The number of Olig2-positive oligodendrocyte precursor cells was unchanged. Four weeks after the last BrdU application, the number of BrdU[LT]-cells with an activated microglia signature was still enhanced in AD mice. None of the newborn cells had differentiated into oligodendrocytes, astrocytes, or neurons. On the basis of these observations, we conclude that amyloid plaque deposition increases proliferation of microglia around plaques but does not affect the proliferation of cortical oligodendrocyte precursor cells. No evidence was found for damage-induced proliferation of reactive astrocytes or for a redirected neurogenesis from the subventricular zone. The proliferation of microglia contributes to the rapid accumulation of microglia around plaques and may play a role in limitating plaque expansion.


Asunto(s)
Enfermedad de Alzheimer/patología , Proliferación Celular , Corteza Cerebral/patología , Regulación de la Expresión Génica/genética , Factores de Edad , Enfermedad de Alzheimer/complicaciones , Enfermedad de Alzheimer/genética , Precursor de Proteína beta-Amiloide/genética , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Bromodesoxiuridina/metabolismo , Complejo CD3/metabolismo , Proteínas de Unión al Calcio/metabolismo , Diferenciación Celular/genética , Modelos Animales de Enfermedad , Gliosis/etiología , Humanos , Antígeno Ki-67/genética , Antígeno Ki-67/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Proteínas de Microfilamentos/metabolismo , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Neuroglía/metabolismo , Neuronas/metabolismo , Factor de Transcripción 2 de los Oligodendrocitos , Presenilina-1/genética , Factores de Transcripción SOXB1/genética , Factores de Transcripción SOXB1/metabolismo , Eliminación de Secuencia/genética
11.
Brain ; 133(10): 3069-79, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20693543

RESUMEN

The recently discovered dendritic cell nuclear protein-1 is the product of a novel candidate gene for major depression. The A allele encodes full-length dendritic cell nuclear protein-1, while the T allele encodes a premature termination of translation at codon number 117 on chromosome 5. In the present study we investigate whether the two forms of dendritic cell nuclear protein-1 might act on corticotropin-releasing hormone, which plays a crucial role in the stress response and in the pathogenesis of depression. The messenger RNA expression of dendritic cell nuclear protein-1 appeared to be increased in the laser micro-dissected paraventricular nucleus of patients with depression compared with control subjects. Dendritic cell nuclear protein-1 was also found to be co-localized with corticotropin-releasing hormone in paraventricular nucleus neurons. Moreover, full-length dendritic cell nucleus protein-1 bound to and transactivated the promoter of corticotropin-releasing hormone in human embryonic kidney 293 cells. We propose that full-length dendritic cell nucleus protein-1 may play a role in the pathogenesis of depressive disorders by enhancing corticotropin-releasing hormone expression in the hypothalamic paraventricular nucleus.


Asunto(s)
Encéfalo/metabolismo , Hormona Liberadora de Corticotropina/metabolismo , Trastorno Depresivo/metabolismo , Neuronas/metabolismo , Proteínas Nucleares/metabolismo , Hormona Liberadora de Corticotropina/genética , Trastorno Depresivo/genética , Humanos , Inmunohistoquímica , Hibridación in Situ , Masculino , Microdisección/métodos , Proteínas Nucleares/genética , Regiones Promotoras Genéticas/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Estadísticas no Paramétricas , Regulación hacia Arriba
12.
FASEB J ; 23(8): 2710-26, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19332645

RESUMEN

Increased expression of the astrocytic intermediate filament protein glial fibrillary acidic protein (GFAP) is a characteristic of astrogliosis. This process occurs in the brain during aging and neurodegeneration and coincides with impairment of the ubiquitin proteasome system. Inhibition of the proteasome impairs protein degradation; therefore, we hypothesized that the increase in GFAP may be the result of impaired proteasomal activity in astrocytes. We investigated the effect of proteasome inhibitors on GFAP expression and other intermediate filament proteins in human astrocytoma cells and in a rat brain model for astrogliosis. Extensive quantitative RT-PCR, immunocytochemistry, and Western blot analysis resulted unexpectedly in a strong decrease of GFAP mRNA to <4% of control levels [Control (DMSO) 100+/-19.2%; proteasome inhibitor (epoxomicin) 3.5+/-1.3%, n=8; P < or = 0.001] and a loss of GFAP protein in astrocytes in vitro. We show that the proteasome alters GFAP promoter activity, possibly mediated by transcription factors as demonstrated by a GFAP promoter-luciferase assay and RT(2) Profiler PCR array for human transcription factors. Most important, we demonstrate that proteasome inhibitors also reduce GFAP and vimentin expression in a rat model for induced astrogliosis in vivo. Therefore, proteasome inhibitors could serve as a potential therapy to modulate astrogliosis associated with CNS injuries and disease.


Asunto(s)
Astrocitos/metabolismo , Filamentos Intermedios/metabolismo , Inhibidores de Proteasoma , Animales , Astrocitos/efectos de los fármacos , Encéfalo/citología , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Línea Celular , Supervivencia Celular , Regulación hacia Abajo , Proteína Ácida Fibrilar de la Glía/genética , Proteína Ácida Fibrilar de la Glía/metabolismo , Células HeLa , Humanos , Proteínas de Filamentos Intermediarios/genética , Proteínas de Filamentos Intermediarios/metabolismo , Masculino , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Nestina , Oligopéptidos/farmacología , Inhibidores de Proteasas/farmacología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Estrés Fisiológico , Factores de Transcripción/metabolismo , Transcripción Genética , Vimentina/genética , Vimentina/metabolismo
13.
Mol Vis ; 15: 1620-30, 2009 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-19693289

RESUMEN

PURPOSE: Diabetic retinopathy (DR) is a leading cause of vision loss and blindness among adults between the age 20 to 74. Changes in ionotropic glutamate receptor subunit composition can affect retinal glutamatergic neurotransmission and, therefore, contribute to visual impairment. The purpose of this study was to investigate whether diabetes leads to changes in ionotropic glutamate receptor subunit expression at the protein and mRNA level in the rat retina. METHODS: Changes in the expression of ionotropic glutamate receptor subunits were investigated at the mRNA and protein levels in retinas of streptozotocin (STZ)-induced diabetic and age-matched control rats. Animals were euthanized one, four and 12 weeks after the onset of diabetes. Retinal protein extracts were prepared, and the receptor subunit levels were assessed by western blotting. Transcript levels were assessed by real-time quantitative PCR. RESULTS: Transcript levels of most ionotropic glutamate receptor subunits were not significantly changed in the retinas of diabetic rats, as compared to age-matched controls but protein levels of alpha-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA), kainate, and N-methyl-D-aspartic acid receptors (NMDA) receptors were found to be altered. CONCLUSIONS: The results provide evidence that diabetes affects the retinal content of ionotropic glutamate receptor subunits at the protein level. The possible implications of these changes on retinal physiology and visual impairment in DR are discussed.


Asunto(s)
Diabetes Mellitus/genética , Diabetes Mellitus/metabolismo , Receptores de Glutamato/genética , Receptores de Glutamato/metabolismo , Retina/metabolismo , Retina/patología , Empalme Alternativo/genética , Animales , Glucemia/metabolismo , Diabetes Mellitus/patología , Subunidades de Proteína/genética , Subunidades de Proteína/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Receptores AMPA/genética , Receptores AMPA/metabolismo , Receptores de Ácido Kaínico/genética , Receptores de Ácido Kaínico/metabolismo , Receptores de N-Metil-D-Aspartato/genética , Receptores de N-Metil-D-Aspartato/metabolismo
14.
Front Cell Neurosci ; 13: 503, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31798416

RESUMEN

Glia alterations in the anterior cingulate cortex (ACC) and dorsolateral prefrontal cortex (DLPFC) have been postulated to play an important role in the pathophysiology of psychiatric disorders. Astroglia is the most abundant type of glial cells in the central nervous system. The expression levels of astrocyte markers (glial fibrillary acidic protein (GFAP), synemin-α, synemin-ß, vimentin, nestin) in isolated gray matter from postmortem ACC and DLPFC were determined to investigate the possible involvement of astrocytes in depression. Donors were aged non-suicidal subjects with bipolar disorder (BPD) or major depressive disorder (MDD), and matched controls. GFAP mRNA levels were significantly increased in the ACC of BPD patients. However, GFAP immunohistochemistry showed that the area fraction of GFAP immunoreactive astrocytes was decreased in the ACC of BPD patients, while there were no changes in the cell density and integrated optical density (IOD), indicating that there might be a reduction of GFAP-positive astrocyte processes and remodeling of the astrocyte network in BPD. Furthermore, in controls, DLPFC GFAP mRNA levels were significantly lower with a time of death at daytime (08:01-20:00 h) compared to nighttime (20:01-08:00 h). In depression, such a diurnal pattern was not present. These findings in BPD and MDD subjects warrant further studies given the crucial roles of astrocytes in the central nervous system.

15.
eNeuro ; 6(1)2019.
Artículo en Inglés | MEDLINE | ID: mdl-30671537

RESUMEN

Many brain regions go through critical periods of development during which plasticity is enhanced. These critical periods are associated with extensive growth and retraction of thalamocortical and intracortical axons. Here, we investigated whether a signaling pathway that is central in Wallerian axon degeneration also regulates critical period plasticity in the primary visual cortex (V1). Wallerian degeneration is characterized by rapid disintegration of axons once they are separated from the cell body. This degenerative process is initiated by reduced presence of cytoplasmic nicotinamide mononucleotide adenylyltransferases (NMNATs) and is strongly delayed in mice overexpressing cytoplasmic NMNAT proteins, such as WldS mutant mice producing a UBE4b-NMNAT1 fusion protein or NMNAT3 transgenic mice. Here, we provide evidence that in WldS mice and NMNAT3 transgenic mice, ocular dominance (OD) plasticity in the developing visual cortex is reduced. This deficit is only observed during the second half of the critical period. Additionally, we detect an early increase of visual acuity in the V1 of WldS mice. We do not find evidence for Wallerian degeneration occurring during OD plasticity. Our findings suggest that NMNATs do not only regulate Wallerian degeneration during pathological conditions but also control cellular events that mediate critical period plasticity during the physiological development of the cortex.


Asunto(s)
Plasticidad Neuronal/fisiología , Nicotinamida-Nucleótido Adenililtransferasa/metabolismo , Corteza Visual/crecimiento & desarrollo , Corteza Visual/metabolismo , Degeneración Walleriana/metabolismo , Animales , Expresión Génica , Ratones Endogámicos C57BL , Ratones Transgénicos , Nicotinamida-Nucleótido Adenililtransferasa/genética , Sinapsis/metabolismo , Técnicas de Cultivo de Tejidos , Agudeza Visual/fisiología
16.
J Neurosci ; 27(3): 564-73, 2007 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-17234588

RESUMEN

Different mutations in the human Crumbs homolog-1 (CRB1) gene cause a variety of retinal dystrophies, such as Leber congenital amaurosis, early onset retinitis pigmentosa (e.g., RP12), RP with Coats-like exudative vasculopathy, and pigmented paravenous retinochoroidal atrophy. Loss of Crb1 leads to displaced photoreceptors and focal degeneration of all neural layers attributable to loss of adhesion between photoreceptors and Müller glia cells. To gain insight into genotype-phenotype relationship, we generated Crb1(C249W) mice that harbor an amino acid substitution (Cys249Trp) in the extracellular sixth calcium-binding epidermal growth factor domain of Crb1. Our analysis showed that Crb1(C249W) as wild-type protein trafficked to the subapical region adjacent to adherens junctions at the outer limiting membrane (OLM). Hence, these data suggest correct trafficking of the corresponding mutant CRB1 in RP12 patients. Crb1(C249W) mice showed loss of photoreceptors in the retina, relatively late compared with mice lacking Crb1. Scanning laser ophthalmoscopy revealed autofluorescent dots that presumably represent layer abnormalities after OLM disturbance. Gene expression analyses revealed lower levels of pituitary tumor transforming gene 1 (Pttg1) transcripts in Crb1(C249W/-) knock-in and Crb1(-/-) knock-out compared with control retinas. Exposure to white light decreased levels of Pttg1 in Crb1 mutant retinas. We hypothesize deregulation of Pttg1 expression attributable to a C249W substitution in the extracellular domain of Crb1.


Asunto(s)
Sustitución de Aminoácidos/genética , Proteínas del Ojo/genética , Regulación de la Expresión Génica/fisiología , Proteínas de la Membrana/genética , Proteínas de Neoplasias/antagonistas & inhibidores , Proteínas de Neoplasias/genética , Proteínas del Tejido Nervioso/genética , Degeneración Retiniana/genética , Secuencia de Aminoácidos , Animales , Cisteína/genética , Proteínas del Ojo/fisiología , Humanos , Proteínas de la Membrana/deficiencia , Proteínas de la Membrana/fisiología , Ratones , Ratones Noqueados , Datos de Secuencia Molecular , Proteínas de Neoplasias/biosíntesis , Proteínas del Tejido Nervioso/deficiencia , Proteínas del Tejido Nervioso/fisiología , Estructura Terciaria de Proteína/genética , Degeneración Retiniana/metabolismo , Degeneración Retiniana/patología , Retinitis Pigmentosa/genética , Retinitis Pigmentosa/metabolismo , Retinitis Pigmentosa/patología , Securina , Triptófano/genética
17.
Brain Res ; 1198: 153-9, 2008 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-18258217

RESUMEN

Early diabetic retinopathy is characterized by changes in subtle visual functions such as contrast sensitivity and dark adaptation. The outcome of several studies suggests that glutamate is involved in retinal neurodegeneration during diabetes. We hypothesized that the protein levels of ionotropic glutamate receptor subunits are altered in the retina during diabetes. Therefore, we investigated whether human diabetic patients have altered immunoreactivity of ionotropic glutamate receptor subunits in the retina. In total, 12 donor eyes from subjects with diabetes mellitus were examined and compared to 6 eyes from non-diabetic subjects without known ocular disease, serving as controls. Immunohistochemical analysis was performed using specific antibodies directed against the ionotropic alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionate (AMPA) receptor subunits GluR1, GluR2, GluR4, and against the N-methyl-d-aspartate glutamate receptor subunit NR1. In the inner plexiform and outer plexiform layers the immunoreactivity of GluR2 and NR1 subunits was significantly increased in subjects with diabetes when compared to the levels found in controls. No significant changes in GluR1 and GluR4 subunit expression were observed. These results suggest that early visual dysfunction in diabetic patients may be due, at least partially, to changes in glutamate receptor subunit expression or distribution.


Asunto(s)
Retinopatía Diabética/metabolismo , Retinopatía Diabética/fisiopatología , Ácido Glutámico/metabolismo , Neuronas/metabolismo , Receptores de Glutamato/genética , Retina/metabolismo , Retina/fisiopatología , Anciano , Retinopatía Diabética/genética , Femenino , Regulación de la Expresión Génica/genética , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Subunidades de Proteína/genética , ARN Mensajero/metabolismo , Receptores AMPA/genética , Receptores de N-Metil-D-Aspartato/genética
18.
Methods Mol Biol ; 418: 129-38, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18287655

RESUMEN

Immunodetection techniques are dependent on enzyme-protein conjugates for the visualization of antigen-antibody complexes. One of the most widely used is the avidin-biotin-peroxidase complex (ABC) method. However, treatment of certain tissues with ABC reagents alone may result in high background, which is indicative for the presence of endogenous biotin or biotinylated proteins. In goldfish and salamander retinal sections, we observed a distinct staining pattern, presumably through binding of avidin to endogenous biotin in Müller cells. These findings summon for caution in the application of detection systems based on biotinylated antibodies or biotinylated DNA probes.


Asunto(s)
Avidina , Biotina/análisis , Técnicas para Inmunoenzimas , Retina/química , Animales , Western Blotting , Reacciones Falso Positivas , Carpa Dorada , Masculino , Ratas , Retina/citología , Urodelos
19.
Mol Vis ; 13: 1892-901, 2007 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-17960128

RESUMEN

PURPOSE: Ischemic conditions in the retina have been implicated in several retinopathological conditions. Experimentally induced ischemia for 60 min followed by reperfusion leads to a loss of neurons in the inner retina. In contrast, a 5 min ischemic episode triggers a series of alterations that protect the retina against the damaging effects of a subsequent 60 min ischemic insult. This phenomenon is called ischemic preconditioning (IPC). To study the changes altered by IPC, we assessed the gene expression patterns in the rat retina after ischemia (60 min) followed by reperfusion (I/R) and compared these to the gene expression patterns after ischemia/reperfusion in preconditioned animals (IPC-I/R). METHODS: Changes in gene expression were studied, by means of microarrays, at 1, 2, 6, and 12 h after I/R in naíve and preconditioned animals. To identify functional pathways of interest, we used significantly regulated genes as input for gene ontology analysis. Microarray results were validated by real-time quantitative PCR. RESULTS: Most genes that were altered by I/R showed a comparable change in both naíve and preconditioned animals. Differential expression was found for a total of 1312 genes of the 20,280 features (6.4%) present on the array with a differential change of 1.7 fold or more. The list of genes with a differential change was characterized by a statistically significant overrepresentation of genes associated to the gene ontology terms tRNA aminoacylation (with a decreased expression due to preconditioning), immune response (with most genes upregulated), and apoptosis (mixed direction of changes). The results of quantitative PCR assays were in agreement with the microarray data. CONCLUSIONS: The response of several functional groups of genes on ischemia was altered by a preconditioning stimulus. Most prominent differences were found for the group of genes encoding for aminoacyl-tRNA synthetases (ARSs), which is in line with the previously observed decreased expression of ARSs after induction of preconditioning. Our observations indicate that activation of translational activity may be a mediator of ischemia-associated damage in the retina, and IPC may prevent activation of this mechanism. An altered expression of genes implicated in immune response and in apoptosis may also be involved in effectuating IPC.


Asunto(s)
Regulación de la Expresión Génica , Isquemia/metabolismo , Precondicionamiento Isquémico , Vasos Retinianos , Aminoacil-ARNt Sintetasas/genética , Aminoacil-ARNt Sintetasas/metabolismo , Aminoacilación/genética , Animales , Formación de Anticuerpos/genética , Apoptosis/genética , Perfilación de la Expresión Génica , Isquemia/genética , Isquemia/inmunología , Masculino , Análisis por Micromatrices , Reacción en Cadena de la Polimerasa , ARN de Transferencia/metabolismo , Ratas , Ratas Wistar , Regulación hacia Arriba
20.
Mol Vis ; 13: 220-8, 2007 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-17327827

RESUMEN

PURPOSE: Retinal ischemia appears to lead to alterations in retinal transcript levels of a group of genes known to be abundantly expressed in the lens. Our purpose is to study whether these alterations are truly the result of retinal ischemia or whether they could be caused by contamination of the retinal tissue with trace amounts of lens tissue. METHODS: Changes occurring in the retinal gene expression profile after induction of retinal ischemia were assessed by oligonucleotide microarrays and by real-time quantitative PCR. RESULTS: Microarray analysis of the retinal gene expression profile after 5 or 60 min ischemia showed altered transcript levels for a group of genes with functions related to "structural constituent of eye lens" (23 genes, predominantly crystallins). Subsequent qPCR assays for this set of genes showed extremely high variations in transcript levels between individual animals of both control and ischemia-treated groups. However, the relative transcript levels, or expression profile, of these genes was constant in all samples. The transcript levels of these genes were on average 2624-times higher in tissue samples isolated from the superficial layers of the total lens. Moreover, all 23 genes had high expression levels in lens compared to retina as was shown by microarray. CONCLUSIONS: From these data, it appears plausible that during isolation of the retina, trace amounts of lens tissue may end up in the studied retinal samples. This would explain the high level of variability in transcript levels of genes, the strong correlation of relative levels between samples, and the link with lens-specific function of the "altered" genes. Changes in crystallin gene expression in other models of retinal degeneration have been reported and a careful examination of the transcript level of other lens-specific genes is essential to rule out a possible confounding effect of lens-material transfer.


Asunto(s)
Cristalinas/genética , Isquemia/metabolismo , Cristalino/metabolismo , ARN/metabolismo , Retina/metabolismo , Vasos Retinianos , Animales , Análisis por Conglomerados , Perfilación de la Expresión Génica , Isquemia/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , Reacción en Cadena de la Polimerasa/métodos , Ratas
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