Normalization of sphingomyelin levels by 2-hydroxyoleic acid induces autophagic cell death of SF767 cancer cells

The very high mortality rate of gliomas reflects the unmet therapeutic need associated with this type of brain tumor. We have discovered that the plasma membrane fulfills a critical role in the propagation of tumorigenic signals, whereby changes in membrane lipid content can either activate or silence relevant pathways. We have designed a synthetic fatty acid, 2-hydroxyoleic acid (2OHOA), that specifically activates sphingomyelin synthase (SGMS), thereby modifying the lipid content of cancer cell membranes and restoring lipid levels to those found in normal cells. In reverting, the structure of the membrane by activating SGMS, 2OHOA inhibits the RAS-MAPK pathway, which in turn fails to acti…

cGMP modulates stem cells differentiation to neurons in brain in vivo pathological implications

During brain development there is a strict control of the proliferation, migration and differentiation of neural stem cells to different cell types. Alterations in the control of these processes may result in altered balance in the formation of different cell types resulting in a long-lasting impairment of cerebral processes. This occurs for example if brain is exposed to alcohol during key stages of development which results in accelerated glial cells formation, impaired neuron formation and impaired cognitive function. The molecular mechanisms modulating differentiation of neural stem cells to neurons or non neuronal cells are not well known. Nitric oxide (NO) plays a relevant role in thi…

Neuronal Activity Drives Localized Blood-Brain-Barrier Transport of Serum Insulin-like Growth Factor-I into the CNS

Upon entry into the central nervous system (CNS), serum insulin-like growth factor-1 (IGF-I) modulates neuronal growth, survival, and excitability. Yet mechanisms that trigger IGF-I entry across the blood-brain barrier remain unclear. We show that neuronal activity elicited by electrical, sensory, or behavioral stimulation increases IGF-I input in activated regions. Entrance of serum IGF-I is triggered by diffusible messengers (i.e., ATP, arachidonic acid derivatives) released during neurovascular coupling. These messengers stimulate matrix metalloproteinase-9, leading to cleavage of the IGF binding protein-3 (IGFBP-3). Cleavage of IGFBP-3 allows the passage of serum IGF-I into the CNS thro…

GFP immunogold staining, from light to electron microscopy, in mammalian cells.

GFP has emerged as an important reporter for monitoring gene expression, protein localization, cell transformation and cell lineage. The development of GFP as a marker in many different biological systems has emphasized the need to image GFP at high resolution. GFP immunogold labeling with colloidal gold particles becomes essential for electron microscopy (EM) ultrastructural detection. Because of the small size, colloidal gold particles require silver enhancement, a procedure to increase the size of the particle as well as gold toning to stabilize the silver layer. GFP preembedding immunogold staining enables high quality cellular-ultrastructural EM analysis mainly for two reasons, on one …

Resistance of subventricular neural stem cells to chronic hypoxemia despite structural disorganization of the germinal center and impairment of neuronal and oligodendrocyte survival

Xavier d'Anglemont de Tassigny,1,* M Salomé Sirerol-Piquer,2,3,* Ulises Gómez-Pinedo,4 Ricardo Pardal,1 Sonia Bonilla,1 Vivian Capilla-Gonzalez,2 Ivette López-López,1 Francisco Javier De la Torre-Laviana,1 José Manuel García-Verdugo,2,3 José López-Barneo1,3 1Medical Physiology and Biophysics Department, Institute of Biomedicine of Seville (IBiS), Virgen del Rocío University Hospital/CSIC/University of Seville, Seville, Spain; 2Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Valencia, Spain; 3Network Center of Biomedical Research on Neurodegenerati…

2-Hydroxyoleate, a nontoxic membrane binding anticancer drug, induces glioma cell differentiation and autophagy

Despite recent advances in the development of new cancer therapies, the treatment options for glioma remain limited, and the survival rate of patients has changed little over the past three decades. Here, we show that 2-hydroxyoleic acid (2OHOA) induces differentiation and autophagy of human glioma cells. Compared to the current reference drug for this condition, temozolomide (TMZ), 2OHOA combated glioma more efficiently and, unlike TMZ, tumor relapse was not observed following 2OHOA treatment. The novel mechanism of action of 2OHOA is associated with important changes in membrane-lipid composition, primarily a recovery of sphingomyelin (SM) levels, which is markedly low in glioma cells bef…

Myelin changes in Alexander disease

Introduction: Alexander disease (AxD) is a type of leukodystrophy. Its pathological basis, along with myelin loss, is the appearance of Rosenthal bodies, which are cytoplasmic inclusions in astrocytes. Mutations in the gene coding for glial fibrillary acidic protein (GFAP) have been identified as a genetic basis for AxD. However, the mechanism by which these variants produce the disease is not understood. Development: The most widespread hypothesis is that AxD develops when a gain-of-function mutation causes an increase in GFAP. However, this mechanism does not explain myelin loss, given that experimental models in which GFAP expression is normal or mutated do not exhibit myelin disorders. …

Phosphodiesterase inhibition induces retinal degeneration, oxidative stress and inflammation in cone-enriched cultures of porcine retina.

nherited retinal degenerations affecting both rod and cone photoreceptors constitute one of the causes 74 of incurable blindness in the developed world. Cyclic guanosine monophosphate (cGMP) is crucial in the 75 phototransduction and, mutations in genes related to its metabolism are responsible for different retinal 76 dystrophies. cGMP-degrading phosphodiesterase 6 (PDE6) mutations cause around 4e5% of the retinitis 77 pigmentosa, a rare form of retinal degeneration. The aim of this study was to evaluate whether phar- 78 macological PDE6 inhibition induced retinal degeneration in cone-enriched cultures of porcine retina 79 similar to that found in murine models. PDE6 inhibition was induced…

Histopathological analysis of human specimens removed from the injection area of expanded adipose-derived stem cells

Coexpresión de NG2/GFAP tras la diferenciación en células transfectadas con las mutaciones de GFAP y en células procedentes de gliomas indiferenciados

Resumen: Introducción: La enfermedad de Alexander es una enfermedad rara causada por mutaciones en el gen que codifica la proteína glial ácida fibrilar (GFAP). En un estudio previo hemos observado que la diferenciación de neuroesferas transfectadas con estas mutaciones genera un tipo celular que comparte la expresión de GFAP y NG2. Objetivos: Determinar el efecto de las mutaciones en marcadores moleculares en comparación con células de glioma diferenciados que expresan simultáneamente GFAP y NG2. Métodos: Se utilizaron muestras de glioblastoma humana (GLM) y neuroesferas procedentes de rata transfectadas con mutaciones de GFAP para el análisis de la expresión tras diferenciación de GFAP y N…

Alexander Disease Mutations Produce Cells with Coexpression of Glial Fibrillary Acidic Protein and NG2 in Neurosphere Cultures and Inhibit Differentiation into Mature Oligodendrocytes

Background Alexander disease (AxD) is a rare disease caused by mutations in the gene encoding glial fibrillary acidic protein (GFAP). The disease is characterized by presence of GFAP aggregates in the cytoplasm of astrocytes and loss of myelin. Objectives Determine the effect of AxD-related mutations on adult neurogenesis. Methods We transfected different types of mutant GFAP into neurospheres using the nucleofection technique. Results We find that mutations may cause coexpression of GFAP and NG2 in neurosphere cultures, which would inhibit the differentiation of precursors into oligodendrocytes and thus explain the myelin loss occurring in the disease. Transfection produces cells that diff…

cGMP MODULATES STEM CELLS DIFFERENTIATION TO NEURONS IN BRAIN IN VIVO

During brain development neural stem cells may differentiate to neurons or to other cell types. The aim of this work was to assess the role of cGMP (cyclic GMP) in the modulation of differentiation of neural stem cells to neurons or non-neuronal cells. cGMP in brain of fetuses was reduced to 46% of controls by treating pregnant rats with nitroarginine-methylester (L-NAME) and was restored by co-treatment with sildenafil.Reducing cGMP during brain development leads to reduced differentiation of stem cells to neurons and increased differentiation to non-neuronal cells. The number of neurons in the prefrontal cortex originated from stem cells proliferating on gestational day 14 was 715 +/- 14/…

Improved technique for stereotactic placement of nerve grafts between two locations inside the rat brain

Peripheral nerve grafts have shown the ability to facilitate central axonal growth and regenerate the adult central nervous system. However, the detailed description of a technique for atraumatic graft placement within the brain is lacking. We present a stereotactic procedure to implant a peripheral nerve graft within a rat's brain with minimal brain tissue damage. The procedure permits a correct graft placement joining two chosen points, and the survival and integration of the graft in the host tissue with a light glial reaction, with evidence of central axonal growth inside the graft, at least up to 8 weeks after its implantation. (C) 2008 Elsevier B.V. All rights reserved.

Exosomal HSP70 for Monitoring of Frontotemporal Dementia and Alzheimer’s Disease: Clinical and FDG-PET Correlation

We aimed to study the expression of circulating heat-shock protein HSP70 and exosomes in plasma of a cohort of patients with Alzheimer's disease (AD) and frontotemporal dementia (FTD) at different stages. We performed correlations with clinical scales and FDG-PET. HSP70 levels were higher within exosomes than free in plasma. Moderate correlations were found between exosomal HSP70 and CDR, FTLD-CDR, and extension of hypometabolism. Our results suggest modifications in the level of exosomal HSP70 during the course of neurodegeneration, regardless of AD or FTD, and therefore HSP70 could have a potential role in the follow-up of these disorders.

Amyotrophic lateral sclerosis modifies progenitor neural proliferation in adult classic neurogenic brain niches.

Background Adult neurogenesis persists through life at least in classic neurogenic niches. Neurogenesis has been previously described as reduced in neurodegenerative diseases. There is not much knowledge about is adult neurogenesis is or not modified in amyotrophy lateral sclerosis (ALS). All previous publications has studied the ALS SOD1 (superoxide dismutase) transgenic mouse model. The purpose of this study is to examine the process of adult neurogenesis in classic niches (subventricular zone [SVZ] and subgranular zone [SGZ] of the dentate gyrus) in patients with amyotrophic lateral sclerosis (ALS), both with (ALS-FTD) and without associated frontotemporal dementia (FTD). Methods We stud…

The Adult Macaque Spinal Cord Central Canal Zone Contains Proliferative Cells And Closely Resembles The Human

The persistence of proliferative cells, which could correspond to progenitor populations or potential cells of origin for tumors, has been extensively studied in the adult mammalian forebrain, including human and nonhuman primates. Proliferating cells have been found along the entire ventricular system, including around the central canal, of rodents, but little is known about the primate spinal cord. Here we describe the central canal cellular composition of the Old World primate Macaca fascicularis via scanning and transmission electron microscopy and immunohistochemistry and identify central canal proliferating cells with Ki67 and newly generated cells with bromodeoxyuridine incorporation…

Additional file 1: Table S1. of Amyotrophic lateral sclerosis modifies progenitor neural proliferation in adult classic neurogenic brain niches

Antibodies used in the immunohistochemical study. Table S2. Summary of patient characteristics. Table S3. Immunohistochemical studies used in ALS diagnosis. Values for TDP-43 and ubiquitin are expressed in inclusions per field; %pTDP-43 represents the percentage of phosphorylated TDP inclusions out of the total. Table S4. Description of neurogenesis patient to patient. Table S5. Neurogenesis findings in the subgranular zone of the hippocampal dentate gyrus, by patient. Table S6. Summary of results in the SVZ. Table S7. Summary of results in the hippocampus. (DOC 302 kb)

Therapeutic effects of hMAPC and hMSC transplantation after stroke in mice.

Stroke represents an attractive target for stem cell therapy. Although different types of cells have been employed in animal models, a direct comparison between cell sources has not been performed. The aim of our study was to assess the effect of human multipotent adult progenitor cells (hMAPCs) and human mesenchymal stem cells (hMSCs) on endogenous neurogenesis, angiogenesis and inflammation following stroke. BALB/Ca-RAG 2(-/-) γC(-/-) mice subjected to FeCl(3) thrombosis mediated stroke were intracranially injected with 2 × 10(5) hMAPCs or hMSCs 2 days after stroke and followed for up to 28 days. We could not detect long-term engraftment of either cell population. However, in comparison w…

Inhibition of adult hippocampal neurogenesis disrupts contextual learning but spares spatial working memory, long-term conditional rule retention and spatial reversal.

Neurogenesis in the adult dentate gyrus (DG) of the hippocampus has been implicated in neural plasticity and cognition but the specific functions contributed by adult-born neurons remain controversial. Here, we have explored the relationship between adult hippocampal neurogenesis and memory function using tasks which specifically require the participation of the DG. In two separate experiments several groups of rats were exposed to fractionated ionizing radiation (two sessions of 7 Gy each on consecutive days) applied either to the whole brain or focally, aiming at a region overlying the hippocampus. The immunocytochemical assays showed that the radiation significantly reduced the expressio…

La alteración de la mielina en la enfermedad de Alexander

Resumen: Introducción: La enfermedad de Alexander (AxD) es una leucodistrofia. Su base patológica, junto a la pérdida de mielina, es la aparición de los cuerpos de Rosenthal, que son inclusiones citoplasmáticas en células astrocitarias. Mutaciones en el gen que codifica la GFAP se han identificado como una base genética para AxD. Sin embargo, no se conoce el mecanismo por el cual estas variantes producen la enfermedad. Desarrollo: La hipótesis más extendida es que AxD se desarrolla por un mecanismo por ganancia de función debido al incremento de GFAP. Sin embargo, este mecanismo no explica la pérdida mielínica, dado que los modelos experimentales que expresan GFAP normal o mutada no generan…

NG2 and GFAP co-expression after differentiation in cells transfected with mutant GFAP and in undifferentiated glioma cells

Introduction: Alexander disease is a rare disorder caused by mutations in the gene coding for glial fibrillary acidic protein (GFAP). In a previous study, differentiation of neurospheres transfected with these mutations resulted in a cell type that expresses both GFAP and NG2. Objective: To determine the effect of molecular marker mutations in comparison to undifferentiated glioma cells simultaneously expressing GFAP and NG2. Methods: We used samples of human glioblastoma (GBM) and rat neurospheres transfected with GFAP mutations to analyse GFAP and NG2 expression after differentiation. We also performed an immunocytochemical analysis of neuronal differentiation for both cell types and dete…

Subventricular zone in motor neuron disease with frontotemporal dementia.

Investigate how the subventricular proliferation and organisation is modified in a patient with FTLD-ALS. We studied the subventricular zone (SVZ) of a patient with FTLD-ALS immunohistochemical and histologically. We found an increase of Ki-67 positive cells and neuroblast in the subventricular zone, suggesting an activation of proliferating activity in response to FTD-ALS. This proliferation can act as a compensatory mechanism for rapid neuronal death and its modulation could provide a new therapeutic pathway in ALS. These results suggest a modification of neurogenesis in FTD-ALS. (C) 2011 Elsevier Ireland Ltd. All rights reserved.