Parkinson's disease (PD) is associated with the degeneration of ventral midbrain dopaminergic neurons (vmDAns) and the accumulation of toxic α-synuclein. A non-cell-autonomous contribution, in ...particular of astrocytes, during PD pathogenesis has been suggested by observational studies, but remains to be experimentally tested. Here, we generated induced pluripotent stem cell-derived astrocytes and neurons from familial mutant LRRK2 G2019S PD patients and healthy individuals. Upon co-culture on top of PD astrocytes, control vmDAns displayed morphological signs of neurodegeneration and abnormal, astrocyte-derived α-synuclein accumulation. Conversely, control astrocytes partially prevented the appearance of disease-related phenotypes in PD vmDAns. We additionally identified dysfunctional chaperone-mediated autophagy (CMA), impaired macroautophagy, and progressive α-synuclein accumulation in PD astrocytes. Finally, chemical enhancement of CMA protected PD astrocytes and vmDAns via the clearance of α-synuclein accumulation. Our findings unveil a crucial non-cell-autonomous contribution of astrocytes during PD pathogenesis, and open the path to exploring novel therapeutic strategies aimed at blocking the pathogenic cross talk between neurons and glial cells.
Peripheral nerve injuries (PNIs) may result in cellular and molecular changes in supraspinal structures possibly involved in neuropathic pain (NPP) maintenance. Activated glial cells in specific ...supraspinal subregions may affect the facilitatory role of descending pathways. Sterile chronic compression injury (sCCI) and complete sciatic nerve transection (CSNT) in rats were used as NPP models to study the activation of glial cells in the subregions of periaqueductal gray (PAG) and rostral ventromedial medulla (RVM). Molecular markers for activated astrocytes (glial fibrillary acidic protein, GFAP) and microglial cells (OX42) were assessed by quantitative immunohistochemistry and western blotting. The cellular distribution of CCL2/CCR2 was monitored using immunofluorescence. sCCI induced both mechanical and thermal hypersensitivity from day 1 up to 3 weeks post-injury. Unilateral sCCI or CSNT for 3 weeks induced significant activation of astrocytes bilaterally in both dorsolateral (dlPAG) and ventrolateral PAG (vlPAG) compared to naïve or sham-operated rats. More extensive astrocyte activation by CSNT compared to sCCI was induced bilaterally in dlPAG and ipsilaterally in vlPAG. Significantly more extensive activation of astrocytes was also found in RVM after CSNT than sCCI. The CD11b immunopositive region, indicating activated microglial cells, was remarkably larger in dlPAG and vlPAG of both sides from sCCI- and CSNT-operated rats compared to naïve or sham-operated controls. No significant differences in microglial activation were detected in dlPAG or vlPAG after CSNT compared to sCCI. Both nerve injury models induced no significant differences in microglial activation in the RVM. Neurons and activated GFAP+ astrocytes displayed CCL2-immunoreaction, while activated OX42+ microglial cells were CCR2-immunopositive in both PAG and RVM after sCCI and CSNT. Overall, while CSNT induced robust astrogliosis in both PAG and RVM, microglial cell activation was similar in the supraspinal structures in both injury nerve models. Activated astrocytes in PAG and RVM may sustain facilitation of the descending system maintaining NPP, while microglial activation may be associated with a reaction to long-lasting peripheral injury. Microglial activation via CCR2 may be due to neuronal and astrocytal release of CCL2 in PAG and RVM following injury.
Astrocytes are involved in many diseases of the central nervous system, not only as reactive cells to neuronal damage but also as primary actors in the pathological process. Astrogliopathy is a term ...used to designate the involvement of astrocytes as key elements in the pathogenesis and pathology of diseases and injuries of the central nervous system. Astrocytopathy is utilized to name non-reactive astrogliosis covering hypertrophy, atrophy and astroglial degeneration with loss of function in astrocytes and pathological remodeling, as well as senescent changes. Astrogliopathy and astrocytopathy are hallmarks of tauopathies—neurodegenerative diseases with abnormal hyper-phosphorylated tau aggregates in neurons and glial cells. The involvement of astrocytes covers different disease-specific types such as tufted astrocytes, astrocytic plaques, thorn-shaped astrocytes, granular/fuzzy astrocytes, ramified astrocytes and astrocytes with globular inclusions, as well as others which are unnamed but not uncommon in familial frontotemporal degeneration linked to mutations in the tau gene. Knowledge of molecular differences among tau-containing astrocytes is only beginning, and their distinct functional implications remain rather poorly understood. However, tau-containing astrocytes in certain conditions have deleterious effects on neuronal function and nervous system integrity. Moreover, recent studies have shown that tau-containing astrocytes obtained from human brain tauopathies have a capacity for abnormal tau seeding and spreading in wild type mice. Inclusive conceptions include a complex scenario involving neurons, glial cells and local environmental factors that potentiate each other and promote disease progression in tauopathies.
Astrocytes are involved in many diseases of the central nervous system, not only as reactive cells to neuronal damage but also as primary actors in the pathological process. Astrogliopathy is a term ...used to designate the involvement of astrocytes as key elements in the pathogenesis and pathology of diseases and injuries of the central nervous system. Astrocytopathy is utilized to name non-reactive astrogliosis covering hypertrophy, atrophy and astroglial degeneration with loss of function in astrocytes and pathological remodeling, as well as senescent changes. Astrogliopathy and astrocytopathy are hallmarks of tauopathies¿neurodegenerative diseases with abnormal hyper-phosphorylated tau aggregates in neurons and glial cells. The involvement of astrocytes covers different disease-specific types such as tufted astrocytes, astrocytic plaques, thorn-shaped astrocytes, granular/fuzzy astrocytes, ramified astrocytes and astrocytes with globular inclusions, as well as others which are unnamed but not uncommon in familial frontotemporal degeneration linked to mutations in the tau gene. Knowledge of molecular differences among tau-containing astrocytes is only beginning, and their distinct functional implications remain rather poorly understood. However, tau-containing astrocytes in certain conditions have deleterious effects on neuronal function and nervous system integrity. Moreover, recent studies have shown that tau-containing astrocytes obtained from human brain tauopathies have a capacity for abnormal tau seeding and spreading in wild type mice. Inclusive conceptions include a complex scenario involving neurons, glial cells and local environmental factors that potentiate each other and promote disease progression in tauopathies.
Provider: - Institution: - Data provided by Europeana Collections- Cristina Blázquez Ortiz ; director Manuel Guzmán Pastor.- Tesis de la Universidad Complutense de Madrid, Facultad de Ciencias ...Biológicas, Departamento de Bioquímica y Biología Molecular I, leída el 10-07-2001.- Los cuerpos cetonicos pueden reemplazar a la glucosa como principal fuente energética cerebral en situaciones en las que está es escasa. Aunque se ha asumido que el hígado es el órgano que aporta cuerpos cetonicos a los tejidos extrahepaticos, existían algunas evidencias en la bibliografía de que los astrocitos también son capaces de producirlos. Así, en este trabajo se ha tratado de caracterizar la ruta cetogenica en astrocitos, estudiar sus mecanismos de regulación, y evaluar su posible papel citoprotector en situaciones patologicas, como la hipoxia y la apoptosis inducida por ácidos grasos. A partir de los resultados obtenidos y a modo de resumen, pueden extraerse las siguientes conclusiones generales: 1,- Los astrocitos son capaces de producir cantidades significativas de cuerpos cetónicos, que podrían ser cedidos a las neuronas para ser utilizados como fuente energética alternativa a la glucosa. Las propiedades de la cetogenesis en astrocitos son muy semejantes a las de la cetogenesis en hepatocitos, lo cual apoya una posible funcionalidad biológica de aquella. 2.-La cetogenesis en astrocitos es un proceso flexible, y se encuentra finamente regulado por al menos dos proteína quinasas, la PKA y la AMPK. Así, un incremento en la concentración de cAMP (que activa la PKA) o de AMP (que activa la AMPK) estimula la producción de cuerpos cetónicos por inactivación de la ACC, descenso en la concentración de malonil-CoA y desinhibición de la CPT-I. Además, la accion activadora directa de la ceramida sobre la CPT-I estimula la producción de cuerpos cetonicos. 3.- La AMPK astrogial podría ejercer un papel ciprotector en situaciones de hipoxia(aumentando el aporte de cuerpos cetónicos a las neuronas) y apoptosis inducida por ácidos grasos (inhibiendo la síntesis de novo de ceramida). La cetogenesis astroglial también podrían impedir algunos de los efectos perjudiciales provocados por la acumulación de ácidos grasos en el cerebro. Así, el equilibrio entre la oxidación de ácidos grasos y la síntesis de ceramida desempeñaría un papel importante en el control de la decisión supervivencia/muerte celular.- Audience: Specialized- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Targeted expression of genes coding for proteins specific to astrocytes, oligodendrocytes and myelin was performed in frontal cortex area 8 of Creutzfeldt-Jakob disease methionine/methionine and ...valine/valine (CJD MM1 and VV2, respectively) compared with controls. GFAP (glial fibrillary acidic protein) mRNA was up-regulated whereas SLC1A2 (solute carrier family 1 member 2, coding for glutamate transporter 1: GLT1), AQ4 (aquaporin 4), MPC1 (mitochondrial pyruvate carrier 1) and UCP5 (mitochondrial uncoupled protein 5) mRNAs were significantly down-regulated in CJD MM1 and CJD VV2, and GJA1 (connexin 43) in CJD VV2. OLIG1 and OLIG2 (oligodendocyte transcription factor 1 and 2, respectively), SOX10 (SRY-Box10) and oligodendroglial precursor cell (OPC) marker NG2 (neuronal/glial antigen) 2 were preserved, but GALC (coding for galactosylceramidase), SLC2A1 (solute carrier family 2 member 1: glucose transporter member 1: GLUT1) and MCT1 (monocarboxylic acid transporter 1) mRNA expression levels were significantly reduced in CJD MM1 and CJD VV2. Expression levels of most genes linked to myelin were not altered in the cerebral cortex in CJD. Immunohistochemistry to selected proteins disclosed individual variations but GFAP, Olig-2, AQ4 and GLUT1 correlated with mRNA levels, whereas GLT1 was subjected to individual variations. However, MPC1, UCP5 and MCT1 decrease was more closely related to the respective reduced neuronal immunostaining. These observations support the idea that molecular deficits linked to energy metabolism and solute transport in astrocytes and oligodendrocytes, in addition to neurons, are relevant in the pathogenesis of cortical lesions in CJD.
Provider: - Institution: - Data provided by Europeana Collections- ES El alcohol es una droga psicoactiva y neurotóxica cuyo abuso puede provocar alteraciones y lesiones cerebrales, junto con ...neurodegeneración. Además, su consumo excesivo en patrones de “binge-drinking” entre los jóvenes se ha incrementado en los últimos años, siendo el responsable del 13,5% de muertes en este grupo. Estudios recientes del Laboratorio de Patología Molecular y Celular del Alcohol del Centro de Investigación Príncipe Felipe (CIPF) han puesto de manifiesto el papel del alcohol en la activación de la ruta de los receptores TLR en cultivos de astroglía y microglía. En concreto, el etanol es capaz de estimular la ruta del receptor TLR4, provocando la señalización del factor de transcripción NF-κB y la posterior liberación de citocinas y otros mediadores inflamatorios, tales como TNF-α o IL-1β. Actualmente, los experimentos de investigación utilizan un número elevado de animales de laboratorio, por lo que resulta esencial la necesidad de planificar un buen diseño experimental y reducir el número de modelos animales, sin que esto afecte a la validez y reproducibilidad de los datos. Por tanto, el objetivo de este trabajo comprende la realización de una comparativa entre un protocolo tradicional de cultivo primario de astrocitos con respecto a una implementación de este, basada en el pase de astrocitos. Para ello, el diseño experimental se fundamenta en el análisis de RT-qPCR e inmunofluorescencia de marcadores inflamatorios relacionados con la ruta de estimulación del receptor TLR4, observando sus niveles de expresión en cultivos tratados con etanol y lipopolisacárido (LPS). Los datos preliminares muestran que el etanol altera los patrones de expresión de los marcadores inflamatorios estudiados en el cultivo tradicional, pero no así en los cultivos alternativos, por lo que se puede concluir la necesidad de realizar futuros experimentos para determinar la significancia de los resultados obtenidos y poder implementar los cultivos.- EN Alcohol is a psychoactive and neurotoxic drug whose abuse can cause brain alterations and lesions, along with neurodegeneration. Moreover, its excessive consumption in binge-drinking patterns among young people has increased in recent years, being responsible for 13.5% of deaths in this group. Recent studies by the Laboratory of Molecular and Cellular Pathology of Alcohol at the Príncipe Felipe Research Centre (CIPF) have highlighted the role of alcohol in the activation of the TLR receptor pathway in astroglia and microglia cultures. Specifically, ethanol can stimulate the TLR4 receptor pathway, leading to signalling of transcription factor NF-κB and the subsequent release of cytokines and other inflammatory mediators, such as TNF-α o IL-1β. Currently, research experiments use a large number of laboratory animals, making it essential to plan a good experimental design and reduce the number of animal models, without affecting the validity and reproducibility of the data. Therefore, the aim of this work is to compare a traditional protocol for primary astrocyte culture with an implementation based on astrocyte passaging. For this purpose, the experimental design is based on RT-qPCR and immunofluorescence analysis of inflammatory markers related to the TLR4 receptor stimulation pathway, observing their expression levels in ethanol and lipopolysaccharide (LPS)-treated cultures. Preliminary data show that ethanol alters the expression patterns of the inflammatory markers studied in the traditional culture, but not in the alternative cultures, so it can be concluded that future experiments are needed to determine the significance of the results obtained and to implement the cultures.- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Targeted expression of genes coding for proteins specific to astrocytes, oligodendrocytes and myelin was performed in frontal cortex area 8 of Creutzfeldt-Jakob disease methionine/methionine and ...valine/valine (CJD MM1 and VV2, respectively) compared with controls. GFAP (glial fibrillary acidic protein) mRNA was up-regulated whereas SLC1A2 (solute carrier family 1 member 2, coding for glutamate transporter 1: GLT1), AQ4 (aquaporin 4), MPC1 (mitochondrial pyruvate carrier 1) and UCP5 (mitochondrial uncoupled protein 5) mRNAs were significantly down-regulated in CJD MM1 and CJD VV2, and GJA1 (connexin 43) in CJD VV2. OLIG1 and OLIG2 (oligodendocyte transcription factor 1 and 2, respectively), SOX10 (SRY-Box10) and oligodendroglial precursor cell (OPC) marker NG2 (neuronal/glial antigen) 2 were preserved, but GALC (coding for galactosylceramidase), SLC2A1 (solute carrier family 2 member 1: glucose transporter member 1: GLUT1) and MCT1 (monocarboxylic acid transporter 1) mRNA expression levels were significantly reduced in CJD MM1 and CJD VV2. Expression levels of most genes linked to myelin were not altered in the cerebral cortex in CJD. Immunohistochemistry to selected proteins disclosed individual variations but GFAP, Olig-2, AQ4 and GLUT1 correlated with mRNA levels, whereas GLT1 was subjected to individual variations. However, MPC1, UCP5 and MCT1 decrease was more closely related to the respective reduced neuronal immunostaining. These observations support the idea that molecular deficits linked to energy metabolism and solute transport in astrocytes and oligodendrocytes, in addition to neurons, are relevant in the pathogenesis of cortical lesions in CJD.
Provider: - Institution: - Data provided by Europeana Collections- Ana Isabel Ramírez Sebastián ; directores Alberto Triviño Casado, Benjamín Fernández Ruiz.- Tesis Universidad Complutense de Madrid, ...Facultad de Ciencias Biológicas, Departamento de Biología Celular (Morfología Microscópica), leída el 13-05-1994.- Se ha estudiado la morfología y distribución de los astrocitos retinianos humanos mediante la inmunodeteccion de la proteína gfa en montajes planos de retina y en secciones, así como mediante m.e. se han encontrado dos tipos de astrocitos: alargados, localizados en la capa de fibras del nervio óptico (fno), relacionados con los axones y los capilares peripapilares radiales y astrocitos estrellados, localizados en la capa de células ganglionares (cg), relacionados fundamentalmente con los vasos sanguíneos de esta capa. En la fno las prolongaciones de los astrocitos alargados forman haces que se alinean en paralelo con los axones; mientras que en la cg, los astrocitos estrellados van interconectando los vasos formando un plexo con morfología en "panal de abeja". Estos últimos astrocitos mandan prolongaciones hasta la nuclear interna acompañando a los vasos intraparenquimatosos formando un plexo de morfología irregular. Los cuerpos celulares de los astrocitos de la cg, pueden agruparse sobre los vasos a modo de racimos. No se han observado los "astrocitos perivasculares", descritos por wolter en la retina humana.- Audience: Specialized- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
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