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Precursor Cells Isolated (precursor + cell_isolated)
Selected AbstractsMuscle precursor cells isolated from aged rats exhibit an increased tumor necrosis factor-, responseAGING CELL, Issue 1 2009Simon J. Lees Summary Improving muscle precursor cell (MPC, muscle-specific stem cells) function during aging has been implicated as a key therapeutic target for improving age-related skeletal muscle loss. MPC dysfunction during aging can be attributed to both the aging MPC population and the changing environment in skeletal muscle. Previous reports have identified elevated levels of tumor necrosis factor-, (TNF-,) in aging, both circulating and locally in skeletal muscle. The purpose of the present study was to determine if age-related differences exist between TNF-,-induced nuclear factor-kappa B (NF-,B) activation and expression of apoptotic gene targets. MPCs isolated from 32-month-old animals exhibited an increased NF-,B activation in response to 1, 5, and 20 ng mL,1 TNF-,, compared to MPCs isolated from 3-month-old animals. No age differences were observed in the rapid canonical signaling events leading to NF-,B activation or in the increase in mRNA levels for TNF receptor 1, TNF receptor 2, TNF receptor-associated factor 2 (TRAF2), or Fas (CD95) observed after 2 h of TNF-, stimulation. Interestingly, mRNA levels for TRAF2 and the cell death-inducing receptor, Fas (CD95), were persistently upregulated in response to 24 h TNF-, treatment in MPCs isolated from 32-month-old animals, compared to 3-month-old animals. Our data indicate that age-related differences may exist in the regulatory mechanisms responsible for NF-,B inactivation, which may have an effect on TNF-,-induced apoptotic signaling. These findings improve our understanding of the interaction between aged MPCs and the changing environment associated with age, which is critical for the development of potential clinical interventions aimed at improving MPC function with age. [source] Modulation of bone morphogenic protein signalling alters numbers of astrocytes and oligodendroglia in the subventricular zone during cuprizone-induced demyelinationJOURNAL OF NEUROCHEMISTRY, Issue 1 2010Holly S. Cate J. Neurochem. (2010) 115, 11,22. Abstract The adult subventricular zone (SVZ) is a potential source of precursor cells to replace neural cells lost during demyelination. To better understand the molecular events that regulate neural precursor cell responsiveness in this context we undertook a microarray and quantitative PCR based analysis of genes expressed within the SVZ during cuprizone-induced demyelination. We identified an up-regulation of the genes encoding bone morphogenic protein 4 (BMP4) and its receptors. Immunohistochemistry confirmed an increase in BMP4 protein levels and also showed an increase in phosphorylated SMAD 1/5/8, a key component of BMP4 signalling, during demyelination. In vitro analysis revealed that neural precursor cells isolated from demyelinated animals, as well as those treated with BMP4, produce more astrocytes. Similarly, there were increased numbers of astrocytes in vivo within the SVZ during demyelination. Intraventricular infusion of Noggin, an endogenous antagonist of BMP4, during cuprizone-induced demyelination reduced pSMAD1/5/8, decreased astrocyte numbers and increased oligodendrocyte numbers in the SVZ. Our results suggest that lineage commitment of SVZ neural precursor cells is altered during demyelination and that BMP signalling plays a role in this process. [source] Differential clustering of Caspr by oligodendrocytes and Schwann cellsJOURNAL OF NEUROSCIENCE RESEARCH, Issue 15 2009Menahem Eisenbach Abstract Formation of the paranodal axoglial junction (PNJ) requires the presence of three cell adhesion molecules: the 155-kDa isoform of neurofascin (NF155) on the glial membrane and a complex of Caspr and contactin found on the axolemma. Here we report that the clustering of Caspr along myelinated axons during development differs fundamentally between the central (CNS) and peripheral (PNS) nervous systems. In cultures of Schwann cells (SC) and dorsal root ganglion (DRG) neurons, membrane accumulation of Caspr was detected only after myelination. In contrast, in oligodendrocytes (OL)/DRG neurons cocultures, Caspr was clustered upon initial glial cell contact already before myelination had begun. Premyelination clustering of Caspr was detected in cultures of oligodendrocytes and retinal ganglion cells, motor neurons, and DRG neurons as well as in mixed cell cultures of rat forebrain and spinal cords. Cocultures of oligodendrocyte precursor cells isolated from contactin- or neurofascin-deficient mice with wild-type DRG neurons showed that clustering of Caspr at initial contact sites between OL processes and the axon requires glial expression of NF155 but not of contactin. These results demonstrate that the expression of membrane proteins along the axolemma is determined by the type of the contacting glial cells and is not an intrinsic characteristic of the axon. © 2009 Wiley-Liss, Inc. [source] Ascorbate-induced differentiation of embryonic cortical precursors into neurons and astrocytesJOURNAL OF NEUROSCIENCE RESEARCH, Issue 2 2003Ji-Yeon Lee Abstract A specific role for ascorbate (AA) in brain development has been postulated based on a rise of AA levels in fetal brain (Kratzing et al., 1985). To evaluate the role of AA during CNS development, we analyzed the survival, proliferation, and differentiation of AA-treated CNS precursor cells isolated from rat embryonic cortex. Immunocytochemical analyses revealed that AA promoted the in vitro differentiation of CNS precursor cells into neurons and astrocytes in a cell density-dependent manner. Additionally, AA increased the frequency and amplitude of miniature excitatory postsynaptic currents (mEPSCs) of postmitotic neurons in primary neuronal cultures. Differential expression analysis of genes specific to neuronal or glial differentiation revealed an AA-dependent increase in the expression of genes that could potentially compound the effects of AA on cell differentiation. These data suggest that AA may act in the developing brain to stimulate the generation of CNS neurons and glia, thereby assisting in the formation of neural circuits by promoting the acquisition of neuronal synaptic functions. © 2003 Wiley-Liss, Inc. [source] | ||||||||||