Search results for "ventricle"
showing 10 items of 431 documents
Cardiac electrical defects in progeroid mice and Hutchinson-Gilford progeria syndrome patients with nuclear lamina alterations
2016
This work was supported by Spanish Ministry of Economy and Competitiveness (MINECO) Grants SAF2010-16044 and SAF2013-46663-R (to V.A.), SAF2011-30312 and SAF2014-58286-C2-1-R (to L.H.-M.), SAF2011-30088 (to E.D.), and SAF2014-52413-R (to C.L.-O.) and Fondo de Investigación Sanitaria del Instituto de Salud Carlos III Grants RD12/0042/0028 (to V.A.), RD12/0042/0011 (to J.T.), and RD12/0042/0002 (to L.H.-M.), with cofunding from the Fondo Europeo de Desarrollo Regional and the Progeria Research Foundation. J.A.G. is the recipient of a U-Mobility Grant from the Marie Curie cofunding of Regional, National and International Programme (Grant 246550). The Instituto Universitario de Oncología is sup…
Large national series of patients with Xq28 duplication involving MECP2: Delineation of brain MRI abnormalities in 30 affected patients.
2016
International audience; Xq28 duplications encompassing MECP2 have been described in male patients with a severe neurodevelopmental disorder associated with hypotonia and spasticity, severe learning disability, stereotyped movements, and recurrent pulmonary infections. We report on standardized brain magnetic resonance imaging (MRI) data of 30 affected patients carrying an Xq28 duplication involving MECP2 of various sizes (228 kb to 11.7 Mb). The aim of this study was to seek recurrent malformations and attempt to determine whether variations in imaging features could be explained by differences in the size of the duplications. We showed that 93% of patients had brain MRI abnormalities such …
Amyotrophic lateral sclerosis modifies progenitor neural proliferation in adult classic neurogenic brain niches.
2017
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…
Bi-layered polyurethane – Extracellular matrix cardiac patch improves ischemic ventricular wall remodeling in a rat model
2016
As an intervention to abrogate ischemic cardiomyopathy, the concept of applying a temporary, local patch to the surface of the recently infarcted ventricle has been explored from a number of design perspectives. Two important features considered for such a cardiac patch include the provision of appropriate mechanical support and the capacity to influence the remodeling pathway by providing cellular or biomolecule delivery. The objective of this report was to focus on these two features by first evaluating the incorporation of a cardiac extracellular matrix (ECM) component, and second by evaluating the impact of patch anisotropy on the pathological remodeling process initiated by myocardial …
Unique Organization of the Nuclear Envelope in the Post-natal Quiescent Neural Stem Cells
2017
Summary Neural stem cells (B1 astrocytes; NSCs) in the adult ventricular-subventricular-zone (V-SVZ) originate in the embryo. Surprisingly, recent work has shown that B1 cells remain largely quiescent. They are reactivated postnatally to function as primary progenitors for neurons destined for the olfactory bulb and some corpus callosum oligodendrocytes. The cellular and molecular properties of quiescent B1 cells remain unknown. Here we found that a subpopulation of B1 cells has a unique nuclear envelope invagination specialization similar to envelope-limited chromatin sheets (ELCS), reported in certain lymphocytes and some cancer cells. Using molecular markers, [3H]thymidine birth-dating, …
Optimization of Lead Placement in the Right Ventricle During Cardiac Resynchronization Therapy. A Simulation Study
2019
[EN] Patients suffering from heart failure and left bundle branch block show electrical ventricular dyssynchrony causing an abnormal blood pumping. Cardiac resynchronization therapy (CRT) is recommended for these patients. Patients with positive therapy response normally present QRS shortening and an increased left ventricle (LV) ejection fraction. However, around one third do not respond favorably. Therefore, optimal location of pacing leads, timing delays between leads and/or choosing related biomarkers is crucial to achieve the best possible degree of ventricular synchrony during CRT application. In this study, computational modeling is used to predict the optimal location and delay of p…
Radial Glial Fibers Promote Neuronal Migration and Functional Recovery after Neonatal Brain Injury.
2018
Radial glia (RG) are embryonic neural stem cells (NSCs) that produce neuroblasts and provide fibers that act as a scaffold for neuroblast migration during embryonic development. Although they normally disappear soon after birth, here we found that RG fibers can persist in injured neonatal mouse brains and act as a scaffold for postnatal ventricular-subventricular zone (V-SVZ)-derived neuroblasts that migrate to the lesion site. This injury-induced maintenance of RG fibers has a limited time window during post-natal development and promotes directional saltatory movement of neuroblasts via N-cadherin-mediated cell-cell contacts that promote RhoA activation. Transplanting an N-cadherin-contai…
Brain size and limits to adult neurogenesis
2015
The walls of the cerebral ventricles in the developing embryo harbor the primary neural stem cells from which most neurons and glia derive. In many vertebrates, neurogenesis continues postnatally and into adulthood in this region. Adult neurogenesis at the ventricle has been most extensively studied in organisms with small brains, such as reptiles, birds, and rodents. In reptiles and birds, these progenitor cells give rise to young neurons that migrate into many regions of the forebrain. Neurogenesis in adult rodents is also relatively widespread along the lateral ventricles, but migration is largely restricted to the rostral migratory stream into the olfactory bulb. Recent work indicates t…
TET3 prevents terminal differentiation of adult NSCs by a non-catalytic action at Snrpn.
2019
Ten-eleven-translocation (TET) proteins catalyze DNA hydroxylation, playing an important role in demethylation of DNA in mammals. Remarkably, although hydroxymethylation levels are high in the mouse brain, the potential role of TET proteins in adult neurogenesis is unknown. We show here that a non-catalytic action of TET3 is essentially required for the maintenance of the neural stem cell (NSC) pool in the adult subventricular zone (SVZ) niche by preventing premature differentiation of NSCs into non-neurogenic astrocytes. This occurs through direct binding of TET3 to the paternal transcribed allele of the imprinted gene Small nuclear ribonucleoprotein-associated polypeptide N (Snrpn), contr…
Adult Neurogenesis Is Sustained by Symmetric Self-Renewal and Differentiation
2018
Somatic stem cells have been identified in multiple adult tissues. Whether self-renewal occurs symmetrically or asymmetrically is key to understanding long-term stem cell maintenance and generation of progeny for cell replacement. In the adult mouse brain, neural stem cells (NSCs) (B1 cells) are retained in the walls of the lateral ventricles (ventricular-subventricular zone [V-SVZ]). The mechanism of B1 cell retention into adulthood for lifelong neurogenesis is unknown. Using multiple clonal labeling techniques, we show that the vast majority of B1 cells divide symmetrically. Whereas 20%-30% symmetrically self-renew and can remain in the niche for several months before generating neurons, …