Search results for "Nerve Tissue Proteins"
showing 10 items of 345 documents
Intra-operatively obtained human tissue: Protocols and techniques for the study of neural stem cells
2009
The discoveries of neural (NSCs) and brain tumor stem cells (BTSCs) in the adult human brain and in brain tumors, respectively, have led to a new era in neuroscience research. These cells represent novel approaches to studying normal phenomena such as memory and learning, as well as pathological conditions such as Parkinson's disease, stroke, and brain tumors. This new paradigm stresses the importance of understanding how these cells behave in vitro and in vivo. It also stresses the need to use human-derived tissue to study human disease because animal models may not necessarily accurately replicate the processes that occur in humans. An important, but often underused, source of human tissu…
Microglial involvement in neuroplastic changes following focal brain ischemia in rats.
2009
The pathogenesis of ischemic stroke is a complex sequence of events including inflammatory reaction, for which the microglia appears to be a major cellular contributor. However, whether post-ischemic activation of microglial cells has beneficial or detrimental effects remains to be elucidated, in particular on long term brain plasticity events. The objective of our study was to determine, through modulation of post-stroke inflammatory response, to what extent microglial cells are involved in some specific events of neuronal plasticity, neurite outgrowth and synaptogenesis. Since microglia is a source of neurotrophic factors, the identification of the brain-derived neurophic factor (BDNF) as…
Stochastic Loss of Silencing of the Imprinted Ndn/NDN Allele, in a Mouse Model and Humans with Prader-Willi Syndrome, Has Functional Consequences
2013
Genomic imprinting is a process that causes genes to be expressed from one allele only according to parental origin, the other allele being silent. Diseases can arise when the normally active alleles are not expressed. In this context, low level of expression of the normally silent alleles has been considered as genetic noise although such expression has never been further studied. Prader-Willi Syndrome (PWS) is a neurodevelopmental disease involving imprinted genes, including NDN, which are only expressed from the paternally inherited allele, with the maternally inherited allele silent. We present the first in-depth study of the low expression of a normally silent imprinted allele, in path…
Resistance to diverse apoptotic triggers in multidrug resistant HL60 cells and its possible relationship to the expression of P-glycoprotein, Fas and…
2002
We studied the human HL60 leukemia cell line and its multidrug resistant (MDR) variant HL60R. In contrast to the HL60, HL60R showed an inability to undergo apoptosis from doxorubicin (Dox) or other different stimuli, including cisplatin, Fas ligation and serum withdrawal. HL60R cells lost surface Fas expression, but we found no evidence that Fas/FasL mediates the apoptotic effects of Dox in HL60. P-glycoprotein (P-gp) did not seem to play a major role as a specific inhibitor of apoptosis. In fact, the P-gp inhibitor verapamil reversed only partially the resistance to Dox-induced apoptosis of the MDR cells. In addition, it did not modify the rate of apoptosis induced from the other stimuli i…
The Endocannabinoid System Promotes Astroglial Differentiation by Acting on Neural Progenitor Cells
2006
Endocannabinoids exert an important neuromodulatory role via presynaptic cannabinoid CB1receptors and may also participate in the control of neural cell death and survival. The function of the endocannabinoid system has been extensively studied in differentiated neurons, but its potential role in neural progenitor cells remains to be elucidated. Here we show that the CB1receptor and the endocannabinoid-inactivating enzyme fatty acid amide hydrolase are expressed, bothin vitroandin vivo, in postnatal radial glia (RC2+cells) and in adult nestin type I (nestin+GFAP+) neural progenitor cells. Cell culture experiments show that CB1receptor activation increases progenitor proliferation and differ…
Altered morphological and electrophysiological properties of Cajal-Retzius cells in cerebral cortex of embryonic Presenilin-1 knockout mice
2004
Mutations of Presenilin-1 are the major cause of familial Alzheimer's disease. Presenilin-1 knockout (PS1-/-) mice develop severe cortical dysplasia related to human type 2 lissencephaly. This overmigration syndrome has been attributed to the premature loss of Cajal-Retzius cells (CRcs), pioneer neurons required for the termination of radial neuronal migration. To elucidate the potential cellular mechanisms responsible for this premature neuronal loss, we investigated the morphological and electrophysiological properties of visually identified CRcs of wild-type (WT) and PS1-/- mouse brains at embryonic day 16.5. The density of CRcs was substantially reduced in the cerebral cortex of PS1-/-.…
Cloning of a rat-specific long PCP4/PEP19 isoform
2007
We report the identification of a cDNA that encodes a putative protein of 94 amino acids and expected molecular weight of 10.7 kDa, the C-terminal half of which is identical to that of PEP19, a small, brain-specific protein involved in Ca++/calmodulin signaling. The novel rat-specific protein, tentatively named long PEP19 isoform (LPI), is the product of alternative splicing of the rat PCP4 gene encoding PEP19. We found that antibodies raised against the first 13 N-terminal amino acids of LPI, not present in PEP19, recognize a protein enriched in the developing rat brain.
Endocytosis in cultured neurons is altered by chronic alcohol exposure.
2010
Endocytosis is required for many cellular pivotal processes, including membrane recycling, nutrient uptake, and signal transduction. This complex process is particularly relevant in polarized cells, such as neurons. Previous studies have demonstrated that alcohol alters intracellular traffic, including endocytosis, in several cell types. However, information on the effect of chronic alcohol exposure on this process in neurons is scarce. As an approach, we investigated the effect of alcohol exposure on the internalization of two widely used endocytic markers, albumin and transferrin, in developing hippocampal neurons in primary culture. The effect of this treatment on the levels of several r…
TGF-β superfamily signaling is essential for tooth and hair morphogenesis and differentiation
2007
Members of the transforming growth factor beta (TGF-beta) superfamily of signaling molecules are involved in the regulation of many developmental processes that involve the interaction between mesenchymal and epithelial tissues. Smad7 is a potent inhibitor of many members of the TGF-beta family, notably TGF-beta and activin. In this study, we show that embryonic overexpression of Smad7 in stratified epithelia using a keratin 5 promoter, results in severe morphogenetic defects in skin and teeth and leads to embryonic and perinatal lethality. To further analyze the functions of Smad7 in epithelial tissues of adult mice, we used an expression system that allowed a controlled overexpression of …
Loss of input from the mossy cells blocks maturation of newly generated granule cells.
2007
The objective of this work is to check whether the input from the mossy cells to the inner molecular layer is necessary for the integration and maturation of the newly generated granule cells of the dentate gyrus (DG) in mice, and if after status epilepticus the sprouting of the mossy fibers can substitute for this projection. Newly generated cells were labeled by administration of 5-bromo-deoxyuridine either before or after pilocarpine administration. The neuronal loss in the hippocampus after administration of pilocarpine combined with scopolamine and diazepam seemed restricted to the hilar mossy cells. The maturation of the granule cells was studied using immunohistochemistry for calreti…