The disruption of mitochondrial axonal transport is an early event in neuroinflammation

Background: in brain inflammatory diseases, axonal damage is one of the most critical steps in the cascade that leads to permanent disability. Thus, identifying the initial events triggered by inflammation or oxidative stress that provoke axonal damage is critical for the development of neuroprotective therapies. Energy depletion due to mitochondrial dysfunction has been postulated as an important step in the damage of axons. This prompted us to study the effects of acute inflammation and oxidative stress on the morphology, transport, and function of mitochondria in axons. Methods: mouse cerebellar slice cultures were challenged with either lipopolysaccharide (LPS) or hydrogen peroxide (H2O2) ex vivo for 24 h. Axonal mitochondrial morphology was evaluated by transmission electron microscopy (TEM) and mitochondrial transportation by time-lapse imaging. In addition, mitochondrial function in the cerebellar slice cultures was analyzed through high-resolution respirometry assays and quantification of adenosine triphosphate (ATP) production. Results: both conditions promoted an increase in the size and complexity of axonal itochondria evident in electron microscopy images, suggesting a compensatory response. Such compensation was reflected at the tissue level as increased respiratory activity of complexes I and IV and as a transient increase in ATP production in response to acute inflammation. Notably, time-lapse microscopy indicated that mitochondrial transport (mean velocity) was severely impaired in axons, increasing the proportion of stationary mitochondria in axons after LPS challenge. Indeed, the two challenges used produced different effects: inflammation mostly reducing retrograde transport and oxidative stress slightly enhancing retrograde transportation. Conclusions: neuroinflammation acutely impairs axonal mitochondrial transportation, which would promote an inappropriate delivery of energy throughout axons and, by this way, contribute to axonal damage. Thus, preserving axonal mitochondrial transport might represent a promising avenue to exploit as a therapeutic target for neuroprotection in brain inflammatory diseases like multiple sclerosis

Aging restricts the ability of mesenchymal stem cells to promote the generation of oligodendrocytes during remyelination.

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system (CNS) that leads to severe neurological deficits. Due to their immunomodulatory and neuroprotective activities and their ability to promote the generation of oligodendrocytes, mesenchymal stem cells (MSCs) are currently being developed for autologous cell therapy in MS. As aging reduces the regenerative capacity of all tissues, it is of relevance to investigate whether MSCs retain their pro-oligodendrogenic activity with increasing age. We demonstrate that MSCs derived from aged rats have a reduced capacity to induce oligodendrocyte differentiation of adult CNS stem/progenitor cells. Aging also abolished the ability of MSCs to enhance the generation of myelin-like sheaths in demyelinated cerebellar slice cultures. Finally, in a rat model for CNS demyelination, aging suppressed the capability of systemically transplanted MSCs to boost oligodendrocyte progenitor cell (OPC) differentiation during remyelination. Thus, aging restricts the ability of MSCs to support the generation of oligodendrocytes and consequently inhibits their capacity to enhance the generation of myelin-like sheaths. These findings may impact on the design of therapies using autologous MSCs in older MS patients.The authors would like to thank the following funding agencies for their support: Paracelsus Medical University PMU-FFF Long-Term Fellowship L-12/01/001-RIV (to and Stand-Alone Grant E-12/15/077-RIT (both to F.J.R.); Chilean Comisión Nacional de Investigación Científica y Tecnológica (CONICYT) FONDECYT Program Regular Grant Nº 1161787 (to F.J.R.), Regular Grant Nº 1141015 (to L.F.B.); Chilean CONICYT PCI Program Grant Nº REDES170233 (to F.J.R.), Grant Nº REDES180139 and Grant Nº REDI170037; Chilean CONICYT FONDEFIDeA Program Grant Nº ID17AM0043 (to M.E.S. and F.J.R.); European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreements N HEALTH-F2-2011-278850 (INMiND) and HEALTH-F2-2011-279288 (IDEA). The work in the Küry laboratory was supported by the German Research Foundation (DFG; KU1934/2_1, KU1934/5-1) and the Christiane and Claudia Hempel Foundation for clinical and iBrain. The work in the Franklin laboratory was supported by grants from the UK Multiple Sclerosis Society and the Adelson Medical Research Foundation, and a core support grant from the Wellcome Trust and MRC to the Wellcome-MRC Cambridge Stem Cell Institute. In addition, the present work was supported by the state of Salzburg (to L.A.). We thank Armin Schneider, Sygnis Pharma AG Heidelberg, Germany, for the MBP promoter construct. We disclose any conflict of interest

Oxidative stress and proinflammatory cytokines contribute to demyelination and axonal damage in a cerebellar culture model of neuroinflammation

Background: Demyelination and axonal damage are critical processes in the pathogenesis of multiple sclerosis (MS). Oxidative stress and pro-inflammatory cytokines elicited by inflammation mediates tissue damage. Methods/Principal Findings: To monitor the demyelination and axonal injury associated with microglia activation we employed a model using cerebellar organotypic cultures stimulated with lipopolysaccharide (LPS). Microglia activated by LPS released pro-inflammatory cytokines (IL-1β, IL-6 and TNFα), and increased the expression of inducible nitric oxide synthase (iNOS) and production of reactive oxygen species (ROS). This activation was associated with demyelination and axonal damage in cerebellar cultures. Axonal damage, as revealed by the presence of non-phosphorylated neurofilaments, mitochondrial accumulation in axonal spheroids, and axonal transection, was associated with stronger iNOS expression and concomitant increases in ROS. Moreover, we analyzed the contribution of pro-inflammatory cytokines and oxidative stress in demyelination and axonal degeneration using the iNOS inhibitor ethyl pyruvate, a free-scavenger and xanthine oxidase inhibitor allopurinol, as well as via blockage of pro-inflammatory cytokines using a Fc-TNFR1 construct. We found that blocking microglia activation with ethyl pyruvate or allopurinol significantly decreased axonal damage, and to a lesser extent, demyelination. Blocking TNFα significantly decreased demyelination but did not prevented axonal damage. Moreover, the most common therapy for MS, interferon-beta, was used as an example of an immunomodulator compound that can be tested in this model. In vitro, interferon-beta treatment decreased oxidative stress (iNOS and ROS levels) and the release of pro-inflammatory cytokines after LPS stimulation, reducing axonal damage. Conclusion: The model of neuroinflammation using cerebellar culture stimulated with endotoxin mimicked myelin and axonal damage mediated by the combination of oxidative stress and pro-inflammatory cytokines. This model may both facilitate understanding of the events involved in neuroinflammation and aid in the development of neuroprotective therapies for the treatment of MS and other neurodegenerative diseases

El tratamiento del espacio exterior en las escuelas innovadoras de educación infantil

En los últimos años, la sociedad que conocemos ha sufrido diversos cambios y con ello, podemos decir que la escuela ha evolucionado substancialmente. Hace 30 años existía una sola escuela única y tradicional y hoy en día, podemos encontrar diversas escuelas. En este proceso han intervenido diferentes causas. Entre ellas podemos encontrar, la aplicación de teorías innovadoras y sus autores más destacados. El cambio en la educación, ha influido en el punto de vista que había sobre la Educación Infantil. Este cambio podemos verlo en diferentes ámbitos de la Educación Infantil y sobre todo en el ámbito del aprendizaje de la ciencia. Como por ejemplo: En el tratamiento del espacio exterior y la importancia de la exploración. En este trabajo analizaremos tres escuelas innovadoras y el tratamiento que le dan al espacio exterior en ellas. Según la teoría de Rosa M Pujol en este proceso tiene que cumplirse 4 fases, para así poder logar un aprendizaje significativo. Para que tratamiento en estas escuelas sea significativo, en el caso de que alguna fase quede débil, deberá ampliarse con una propuesta pedagógica adecuada. Como se va a poder ver, con este cambio en la educación han surgido diversas escuelas innovadoras y entre ellas muy diferentes.Azkeneko urteetan, ezagutzen dugun gizarteak aldaketa anitz izan dituen bitartean eskolak ere eraldaketa bat jasan du. Duela 30 urte eskola bakarra eta tradizionala geneukan eta gaur egun, eskola anitzak aurkitu ditzakegu. Prozesu honetan hainbat eragilek hartu dute parte. Horien artean teoria berritzaile eta egile esanguratsu asko aurkitu ditzakegu. Hezkuntzan jasan den eraldaketak, haur hezkuntza ikusteko eta ulertzeko ikuspuntua aldatu du. Haur Hezkuntzaren eremu ezberdinetan ikusi genezake aldaketa hau eta batez ere Zientzia eremuko hezkuntzan. Esaterako: kanpo espazioarekiko trataeran eta esplorazioaren garrantzian. Hau ikusteko, hiru ikastetxe berritzaile Kanpo Eremua nola erabiltzen lantzen duten aztertuko dut. Rosa Maria Pujolen hitzetan 4 fase bete behar dira, ikaskuntza esanguratsu egokia lortzeko. Ikastetxe hauen trataera esanguratsua izatekotan ere faseren bat ahul gelditzekotan, proposamen pedagogiko egokiak behar zaizkio eman. Ikusiko den bezala, hezkuntzan egon den eraldaketa honek ikastetxe berritzaile anitzak sortu ditu eta denak oso ezberdinak haien artean.In the last years, the society that we know, has suffer various changes and with it, the school has turned around. 30 years ago, there was only, one traditional school system, and nowadays, we can find several schools. Different causes have intervened in this process. Among them, we can find some innovative theories and their most influential authors. The change in education has influenced the view that we had about pre- primary education. We can see it in different areas of pre-primary education and especially in sciences area. For example: The treatment of outside space and the importance of the exploration. In order to see it, you are going to see tree innovative schools and the treatment they give to outside space. According to Rosa Mª Pujol´s theory, this process must have 4 phases, in order to achieve a meaningful learning. The treatment in these schools must be significant and if not, it has to be improved with an appropriate pedagogical proposal. As you will be able to see, with this change in education, have emerged several innovative schools and they are very different each other.Graduado o Graduada en Maestro en Educación Infantil por la Universidad Pública de NavarraHaur Hezkuntzako Irakasletzan Graduatua Nafarroako Unibertsitate Publikoa

Mecanismos de degeneración axonal en neuroinflamación: papel de la disfunción mitocondrial

[spa] La Esclerosis Múltiple (EM) afecta preferentemente a la conectividad cerebral lesionando los axones de forma irreversible, siendo esta lesión la principal causa de la discapacidad permanente de los pacientes. El daño axonal se produce de forma aguda debido a la cascada inflamatoria y de forma crónica (degenerativa) debido a la falta de soporte trófico de la mielina, un microambiente alterado (gliótico) y persistencia de inflamación crónica (activación microglial). Los axones son dañados en la fase aguda por el estrés oxidativo y energético y mecanismos de citotoxicidad, produciéndose un fallo del transporte axonal y un fallo de la función mitocondrial. Todos estos procesos culminan en el déficit energético, que pone en marcha mecanismos activos de transección axonal que llevan a la lesión axonal aguda. Los mecanismos de daño axonal crónico serían en parte similares a los agudos (déficit energético) extendidos en el tiempo, junto con el fallo de soporte trófico de la mielina, la modificación de la función y distribución de los canales iónicos y la consecuente alteración del microambiente. Identificar los mecanismos y la dinámica del daño axonal agudo y crónico en la EM permitirá identificar dianas terapéuticas para las que se desarrollarían nuevas terapias neuroprotectoras que disminurían el daño axonal en la EM y por tanto las secuelas. El objetivo del proyecto es analizar distintos aspectos de la biología mitocondrial y de su función respiratoria y energética relacionados con la degeneración axonal en un entorno neuroinflamatorio agudo. Para conseguirlo se ha utilizado un modelo de neuroinflamación in vitro consistente en cultivos organotípicos de cerebelo de ratón estimulados con lipopolisacárido bacteriano (LPS) y los cambios se han evaluado mediante técnicas de microscopía avanzada y biología molecular. A lo largo del estudio de la biología mitocondrial también se ha utilizado un estímulo causante de estrés oxidativo, el peróxido de hidrógeno (H2O2), proceso que forma parte de la neuroinflamación y afecta directamente a la función de los complejos de la cadena respiratoria mitocondrial. Los resultados del estudio nos llevan a proponer el siguiente modelo de la respuesta mitocondrial en un entorno neuroinflamatorio agudo: mientras que a nivel tisular las mitocondrias responden aumentando su capacidad respiratoria y la producción de ATP, a nivel axonal las mitocondrias responden morfológicamente a la inflamación aumentando su tamaño y la complejidad de sus crestas mitocondriales, pero su transporte se ve completamente alterado. La paralización de las mitocondrias se produce en una etapa temprana y aguda de la inflamación, antes de que los daños axonales sean irreversibles. Por tanto, nuestro modelo indica que el mecanismo más crítico en la disfunción mitocondrial en la neuroinflamación aguda es la alteración del transporte axonal de mitocondrias (especialmente el retrógrado). Por tanto, nuestro estudio sugiere la preservación del transporte mitocondrial como una diana terapéutica de neuroprotección en lesiones agudas de EM.[eng] The main cause of permanent disability in Multiple Sclerosis (MS) patients is axonal degeneration. In acute phases of the disease axonal damage is a consequence of the inflammatory cascade and oxidative stress that cause direct damage to mitochondria, inhibiting OXPHOS complexes. In more chronic phases axonal degeneration is due to loss of myelin trophic support, gliosis, redistribution of axonal sodium channels and extended energetic deficiency. Mitochondrial dysfunction is a common player in both stages. Therefore, the elucidation of axonal degeneration mechanisms is important for the identification of new therapeutic targets and the development of neuroprotective therapies that decrease axonal damage in MS. The objective of the project is to analyze different aspects of mitochondrial biology and their respiratory and energetic functions related with axonal degeneration in an acute neuroinflammatory environment. Organotypic slice cultures of mouse cerebellum were stimulated with LPS to activate microglia and simulate neuroinflammation, and mitochondrial changes were evaluated with advanced techniques of molecular biology and microscopy. The results suggest that tissular mitochondria are responding to acute neuroinflammation increasing their respiratory capacity and their production of ATP, and axonal mitochondria react morphologically increasing their size and their cristae complexity. However, axonal mitochondrial transport is completely impaired, in an early stage of acute inflammation before axonal damage is irreversible. Therefore, we propose that the critical mechanism of mitochondrial dysfunction in acute neuroinflammation is the impairment of axonal mitochondrial transport. As a result, the preservation of axonal mitochondrial transport represents a therapeutic target for neuroprotection in acute MS lesions

Correction to: the disruption of mitochondrial axonal transport is an early event in neuroinflammation

Abstract After publication of the article [1], it has been brought to our attention that the full funding acknowledgement is missing from the original article. It should also include the following – “This work was supported by the Instituto de Salud Carlos III with FEDER funds (Otra forma de hacer Europa) from the European Commission (FIS: PI12/01823)”

The disruption of mitochondrial axonal transport is an early event in neuroinflammation

Background: in brain inflammatory diseases, axonal damage is one of the most critical steps in the cascade that leads to permanent disability. Thus, identifying the initial events triggered by inflammation or oxidative stress that provoke axonal damage is critical for the development of neuroprotective therapies. Energy depletion due to mitochondrial dysfunction has been postulated as an important step in the damage of axons. This prompted us to study the effects of acute inflammation and oxidative stress on the morphology, transport, and function of mitochondria in axons. Methods: mouse cerebellar slice cultures were challenged with either lipopolysaccharide (LPS) or hydrogen peroxide (H2O2) ex vivo for 24 h. Axonal mitochondrial morphology was evaluated by transmission electron microscopy (TEM) and mitochondrial transportation by time-lapse imaging. In addition, mitochondrial function in the cerebellar slice cultures was analyzed through high-resolution respirometry assays and quantification of adenosine triphosphate (ATP) production. Results: both conditions promoted an increase in the size and complexity of axonal itochondria evident in electron microscopy images, suggesting a compensatory response. Such compensation was reflected at the tissue level as increased respiratory activity of complexes I and IV and as a transient increase in ATP production in response to acute inflammation. Notably, time-lapse microscopy indicated that mitochondrial transport (mean velocity) was severely impaired in axons, increasing the proportion of stationary mitochondria in axons after LPS challenge. Indeed, the two challenges used produced different effects: inflammation mostly reducing retrograde transport and oxidative stress slightly enhancing retrograde transportation. Conclusions: neuroinflammation acutely impairs axonal mitochondrial transportation, which would promote an inappropriate delivery of energy throughout axons and, by this way, contribute to axonal damage. Thus, preserving axonal mitochondrial transport might represent a promising avenue to exploit as a therapeutic target for neuroprotection in brain inflammatory diseases like multiple sclerosis