Search results for "Cell Differentiation"
showing 10 items of 907 documents
N-methyl-d-aspartate receptor expression during adult neurogenesis in the rat dentate gyrus.
2006
Abstract N -methyl- d -aspartate (NMDA) receptors play a crucial role in the regulation of neuronal development during embryogenesis and they also regulate the rate of neurogenesis and proliferation in the adult dentate gyrus. However, the mechanism by which they influence these processes is not fully understood. NMDA receptors seem to be functional in hippocampal precursor cells and recently generated granule neurons, although there is no anatomical correlate of these physiological observations. We have analyzed the expression of the NMDA receptor subunits NR1 and NR2B in precursor cells and recently generated granule neurons of the adult rat dentate gyrus, using 5′bromodeoxyuridine, green…
Cycloastragenol as an Exogenous Enhancer of Chondrogenic Differentiation of Human Adipose-Derived Mesenchymal Stem Cells. A Morphological Study
2020
Stem cell therapy and tissue engineering represent a promising approach for cartilage regeneration. However, they present limits in terms of mechanical properties and premature de-differentiation of engineered cartilage. Cycloastragenol (CAG), a triterpenoid saponin compound and a hydrolysis product of the main ingredient in Astragalus membranaceous, has been explored for cartilage regeneration. The aim of this study was to investigate CAG&rsquo
Changes in the expression of cation-Cl- cotransporters, NKCC1 and KCC2, during cortical malformation induced by neonatal freeze-lesion.
2007
Focal cortical malformations comprise a heterogeneous group of disturbances in brain development, often associated with intractable epilepsy. A focal freeze-lesion of cerebral cortex in newborn rat produces a cortical malformation that resembles human polymicrogyria, clinical conditions that results from abnormal neuronal migration. The change in GABAergic functions that occurs during early brain development is induced by an alteration in Cl(-) homeostasis and plays important roles in neocortical development by modulating such events as laminar organization and synaptogenesis. We therefore investigated the relationship between pathogenesis of polymicrogyria and ontogeny of Cl(-) homeostasis…
Monocytes derived from humanized neonatal NOD/SCID/IL2Rγ(null) mice are phenotypically immature and exhibit functional impairments.
2012
Trials of immune-modulating drugs in septic patients have mostly failed to demonstrate clinical efficacy. Thus, we sought to generate a surrogate model of myelomonocytic lineage differentiation that would potentially allow sepsis induction and preclinical testing of anti-inflammatory drugs. Comparing transplantation of cord blood-derived stem cells in neonatal NOD/SCID/IL2Rγ(null) (neonatal huNSG) mice with transplantation of adult peripheral mobilized stem cells into adult NSG (adult huNSG) recipients, we demonstrate that myelomonocytic lineage differentiation in neonatal huNSG mice is retarded and monocytes are phenotypically immature with respect to HLA-DR expression and the emergence of…
Expression pattern of Notch1, 2 and 3 and Jagged1 and 2 in lymphoid and stromal thymus components: distinct ligand–receptor interactions in intrathym…
1999
The suggested role of Notch1 or its mutants in thymocyte differentiation and T cell tumorigenesis raises the question of how the different members of the Notch family influence distinct steps in T cell development and the role played by Notch ligands in the thymus. We report here that different Notch receptor-ligand partnerships may occur inside the thymus, as we observed differential expression of Notch1, 2 and 3 receptors, their ligands Jagged1 and 2, and downstream intracellular effectors hairy and Enhancer of Split homolog 1 (HES-1) and hairy and Enhancer of Split homolog 5 (HES-5), depending on ontogenetic stage and thymic cell populations. Indeed, while Jagged2 is expressed in both st…
Study of adult neurogenesis in the Gallotia galloti lizard during different seasons.
2011
In a previous study we found a seasonal distribution of cell proliferation (the first stage of adult neurogenesis) in the telencephalic ventricular walls of the adult Gallotia galloti lizard. The aim of the present work was to determine the influence of seasonality on the subsequent migration of the resulting immature neurons. We used wild animals injected with bromodeoxyuridine and kept in captivity within 30 days. To confirm the neuronal identity of these cells, we used double immunohistochemical 5-bromo-2'-deoxyuridine (BrdU) and doublecortin (DCX, an early neuronal marker) labeling, as well as autoradiography after the administration of methyl-[³H]thymidine ([³H]T). We found that: (1) t…
Lysosomal Signaling Licenses Embryonic Stem Cell Differentiation via Inactivation of Tfe3
2019
International audience; Self-renewal and differentiation of pluripotent murine embryonic stem cells (ESCs) is regulated by extrinsic signaling pathways. It is less clear whether cellular metabolism instructs developmental progression. In an unbiased genome-wide CRISPR/Cas9 screen, we identified components of a conserved amino-acid-sensing pathway as critical drivers of ESC differentiation. Functional analysis revealed that lysosome activity, the Ragulator protein complex, and the tumor-suppressor protein Folliculin enable the Rag GTPases C and D to bind and seclude the bHLH transcription factor Tfe3 in the cytoplasm. In contrast, ectopic nuclear Tfe3 represses specific developmental and met…
Human somatic cells subjected to genetic induction with six germ line-related factors display meiotic germ cell-like features
2016
AbstractThe in vitro derivation of human germ cells has attracted interest in the last years, but their direct conversion from human somatic cells has not yet been reported. Here we tested the ability of human male somatic cells to directly convert into a meiotic germ cell-like phenotype by inducing them with a combination of selected key germ cell developmental factors. We started with a pool of 12 candidates that were reduced to 6, demonstrating that ectopic expression of the germ line-related genes PRDM1, PRDM14, LIN28A, DAZL, VASA and SYCP3 induced direct conversion of somatic cells (hFSK (46, XY) and hMSC (46, XY)) into a germ cell-like phenotype in vitro. Induced germ cell-like cells …
Anaplastic Wilms' tumour, a subtype displaying poor prognosis, harbours p53 gene mutations
1994
The genetics of Wilms' tumour (WT), a paediatric malignancy of the kidney, is complex. Inactivation of the tumour suppressor gene, WT1, is associated with tumour aetiology in approximately 10-15% of WTs. Chromosome 17p changes have been noted in cytogenetic studies of WTs, prompting us to screen 140 WTs for p53 mutations. When histopathology reports were available, p53 mutations were present in eight of eleven anaplastic WTs, a tumour subtype associated with poor prognosis. Amplification of MDM2, a gene whose product binds and sequesters p53, was excluded. Our results indicate that p53 alterations provide a molecular marker for anaplastic WTs.
HACD1, a regulator of membrane composition and fluidity, promotes myoblast fusion and skeletal muscle growth
2015
International audience; The reduced diameter of skeletal myofibres is a hallmark of several congenital myopathies, yet the underlying cellular and molecular mechanisms remain elusive. In this study, we investigate the role of HACD1/PTPLA, which is involved in the elongation of the very long chain fatty acids, in muscle fibre formation. In humans and dogs, HACD1 deficiency leads to a congenital myopathy with fibre size disproportion associated with a generalized muscle weakness. Through analysis of HACD1-deficient Labradors, Hacd1-knockout mice, and Hacd1-deficient myoblasts, we provide evidence that HACD1 promotes myoblast fusion during muscle development and regeneration. We further demons…