References of "Leprince, Pierre"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailA 295-Kda Intermediate Filament-Associated Protein in Radial Glia and Developing Muscle Cells in Vivo and in Vitro
Chanas-Sacre, Grazyna; Thiry, Marc ULg; Pirard, Sandrine et al

in Developmental Dynamics : An Official Publication of the American Association of Anatomists (2000), 219(4), 514-25

The RC2 antibody is frequently used to label mouse radial glial cells in all parts of the nervous system where neuronal migration occurs during embryonic and early postnatal life. The antigen recognized ... [more ▼]

The RC2 antibody is frequently used to label mouse radial glial cells in all parts of the nervous system where neuronal migration occurs during embryonic and early postnatal life. The antigen recognized by this antibody still needs to be identified. We have characterized further its localization in vivo, its expression and subcellular localization in vitro, as well as its molecular nature. Histologic investigations of whole mouse embryos reveal an equally intense expression of RC2 immunostaining in radial glial cells in brain and spinal cord and in skeletal muscle. In glial cells cultures, the RC2 antibody recognizes an epitope located on the glial cytoskeleton and identified as an intermediate filament associated protein (IFAP) at the ultrastructural level. RC2 immunostaining in those cells is strongly dependent on the presence of a serum-derived activity. Serum-removal causes a decrease of the staining while adding serum back to the cells induces reexpression of RC2 immunoreactivity. By Western blotting, we find that in intermediate filament (IF) preparations obtained from cultured cerebellar glia, the RC2 antibody recognizes a 295-kDa protein whose expression is also dependent on the presence of serum in culture medium. In developing muscle cells, RC2 immunostaining is observed from the myoblast stage and disappears after complete myotube fusion. Both in vivo and in vitro, staining is first seen as a loose capping around myoblasts nuclei and progressively concentrates into Z-disks in association with the muscle IF protein desmin. The RC2 antibody also recognizes a 295-kDa protein band in muscle tissue protein extracts. Thus, the RC2 antibody recognizes a developmentally regulated cytoskeletal protein that is expressed, like other previously identified IFAPs, by cells of the glial and myogenic lineages and whose expression in vitro seems to be controlled by a signaling mechanism known to modulate astroglial morphology. [less ▲]

Detailed reference viewed: 81 (4 ULg)
Peer Reviewed
See detailRadial Glia Phenotype: Origin, Regulation, and Transdifferentiation
Chanas-Sacre, Grazyna; Rogister, Bernard ULg; Moonen, Gustave ULg et al

in Journal of Neuroscience Research (2000), 61(4), 357-63

Radial glial cells play a major guidance role for migrating neurons during central nervous system (CNS) histogenesis but also play many other crucial roles in early brain development. Being among the ... [more ▼]

Radial glial cells play a major guidance role for migrating neurons during central nervous system (CNS) histogenesis but also play many other crucial roles in early brain development. Being among the earliest cells to differentiate in the early CNS, they provide support for neuronal migration during embryonic brain development; provide instructive and neurotrophic signals required for the survival, proliferation, and differentiation of neurons; and may be multipotential progenitor cells that give rise to various cell types, including neurons. Radial glial cells constitute a major cell type of the developing brain in numerous nonmammalian and mammalian vertebrates, increasing in complexity in parallel with the organization of the nervous tissue they help to build. In mammalian species, these cells transdifferentiate into astrocytes when neuronal migration is completed, whereas, in nonmammalian species, they persist into adulthood as a radial component of astroglia. Thus, our perception of radial glia may have to change from that of path-defining cells to that of specialized precursor cells transiently fulfilling a guidance role during brain histogenesis. In that respect, their apparent change of phenotype from radial fiber to astrocyte probably constitutes one of the most common transdifferentiation events in mammalian development. [less ▲]

Detailed reference viewed: 36 (4 ULg)
Full Text
Peer Reviewed
See detailGlycine Triggers an Intracellular Calcium Influx in Oligodendrocyte Progenitor Cells Which Is Mediated by the Activation of Both the Ionotropic Glycine Receptor and Na+-Dependent Transporters
Belachew, Shibeshih ULg; Malgrange, Brigitte ULg; Rigo, Jean-Michel et al

in European Journal of Neuroscience (2000), 12(6), 1924-30

Using fluo-3 calcium imaging, we demonstrate that glycine induces an increase in intracellular calcium concentration ([Ca2+]i) in cortical oligodendrocyte progenitor (OP) cells. This effect results from a ... [more ▼]

Using fluo-3 calcium imaging, we demonstrate that glycine induces an increase in intracellular calcium concentration ([Ca2+]i) in cortical oligodendrocyte progenitor (OP) cells. This effect results from a calcium entry through voltage-gated calcium channels (VGCC), as it is observed only in OP cells expressing such channels, and it is abolished either by removal of calcium from the extracellular medium or by application of an L-type VGCC blocker. Glycine-triggered Ca2+ influx in OP cells actually results from an initial depolarization that is the consequence of the activation of both the ionotropic glycine receptor (GlyR) and Na+-dependent transporters, most probably the glycine transporters 1 (GLYT1) and/or 2 (GLYT2) which are colocalized in these cells. Through this GlyR- and transporter-mediated effect on OP intrcellular calcium concentration [Ca2+]i, glycine released by neurons may, as well as other neurotransmitters, serve as a signal between neurons and OP during development. [less ▲]

Detailed reference viewed: 75 (5 ULg)
Peer Reviewed
See detailIdentification of Psf, the Polypyrimidine Tract-Binding Protein-Associated Splicing Factor, as a Developmentally Regulated Neuronal Protein
Chanas-Sacre, Grazyna; Mazy-Servais, Cécile; Wattiez, Ruddy et al

in Journal of Neuroscience Research (1999), 57(1), 62-73

The polypyrimidine tract-binding protein-associated splicing factor (PSF), which plays an essential role in mammalian spliceosomes, has been found to be expressed by differentiating neurons in developing ... [more ▼]

The polypyrimidine tract-binding protein-associated splicing factor (PSF), which plays an essential role in mammalian spliceosomes, has been found to be expressed by differentiating neurons in developing mouse brain. The sequence of a fragment of mouse PSF was found to be remarkably similar to that of human PSF. Both the expression of PSF mRNA in cortex and cerebellum and PSF immunoreactivity in all brain areas were high during embryonic and early postnatal life and almost disappeared in adult tissue, except in the hippocampus and olfactory bulb where various neuronal populations remained PSF-immunopositive. Double-labeling experiments with anti-PSF antibody and anti-neurofilaments or anti-glial fibrillary acidic protein antibodies on sections of cortex, hippocampus, and cerebellum indicate that PSF is expressed by differentiating neurons but not by astrocytic cells. In vitro, mouse PSF was found to be expressed by differentiating cortical and cerebellar neurons. Radial glia or astrocyte nuclei were not immunopositive; however, oligodendrocytes differentiating in vitro were found to express PSF. The restricted expression of PSF suggests that this splicing factor could be involved in the control of neuronal-specific splicing events occurring at particular stages of neuronal differentiation and maturation. [less ▲]

Detailed reference viewed: 53 (6 ULg)
Full Text
Peer Reviewed
See detailEffects of Macrophage Transplantation in the Injured Adult Rat Spinal Cord: A Combined Immunocytochemical and Biochemical Study
Franzen, Rachelle ULg; Schoenen, Jean ULg; Leprince, Pierre ULg et al

in Journal of Neuroscience Research (1998), 51(3), 316-27

Early and robust invasion by macrophages may be one of the reasons why axonal regeneration is more effective in the PNS than in the CNS. Therefore, we have grafted autologous peritoneal macrophages ... [more ▼]

Early and robust invasion by macrophages may be one of the reasons why axonal regeneration is more effective in the PNS than in the CNS. Therefore, we have grafted autologous peritoneal macrophages labeled with fluorescent latex microspheres into spinal cord compression lesions. At various survival times, we have studied their effect on the expression of neuronal (neurofilaments [NF], calcitonin gene-related peptide [CGRP], 5-hydroxytryptamine [5-HT]) and nonneuronal markers (myelin-associated glycoprotein [MAG], glial fibrillary acidic protein [GFAP], laminin) by using semiquantitative Western blot and immunohistochemical techniques. After 1 month, we observed a significant decrease of the expression of MAG as well as an important invasion of the lesion site by neurites, chiefly peptidergic axons of presumed dorsal root origin, in macrophage-grafted animals compared with controls. In addition, angiogenesis and Schwann cell infiltration were more pronounced after macrophage grafts, providing an increase in laminin, a favorable substrate for axonal regrowth. By using reverse transcription-polymerase chain reaction (RT-PCR), mRNAs for tumor necrosis factor-alpha (TNF-alpha) were detected in the transplanted cells, whereas results were negative for nerve growth factor (NGF), neurotrophin-3 (NT-3), brain-derived neurotrophic factor (BDNF), or acidic fibroblast growth factor (aFGF) and basic fibroblast growth factor (bFGF). Thus, macrophage grafts may represent an interesting strategy to promote axonal regeneration in the CNS. Our study suggests that they may exert their beneficial effects by degrading myelin products, which inhibit axonal regrowth, and by promoting a permissive extracellular matrix containing notably laminin. No evidence for a direct synthesis of neurotrophic factors by the transplanted macrophages was found in this study, but resident glial cells could secrete such factors as a result of stimulation by macrophage-released cytokines. [less ▲]

Detailed reference viewed: 23 (1 ULg)
Full Text
Peer Reviewed
See detailA novel biodegradable and biocompatible ceramer prepared by the sol-gel process
Tian, Dong; Dubois, Philippe ULg; Grandfils, Christian ULg et al

in Chemistry of Materials (1997), 9(4), 871-874

Detailed reference viewed: 44 (13 ULg)
Full Text
Peer Reviewed
See detailProtein Kinase- and Staurosporine-Dependent Induction of Neurite Outgrowth and Plasminogen Activator Activity in Pc12 Cells
Leprince, Pierre ULg; Bonvoisin, Catherine ULg; Rogister, Bernard ULg et al

in Biochemical Pharmacology (1996), 52(9), 1399-405

We analysed how interactions between protein kinase-dependent intracellular signalling pathways were implicated in the control of the production of tissue-type plasminogen activator (tPA) and the ... [more ▼]

We analysed how interactions between protein kinase-dependent intracellular signalling pathways were implicated in the control of the production of tissue-type plasminogen activator (tPA) and the generation of neurite outgrowth by PC12 cells. To that aim, cells were treated with agents that interact with the trk receptor and with protein kinases A and C. Nerve growth factor induced only the formation of large neurites. The release of the protease and the production of short neurite outgrowth were found to be protein-kinase-A-dependent events that could be enhanced by simultaneous activation of protein kinase C with phorbol ester. At high concentration, staurosporine, a nonselective inhibitor of protein kinases, induced the production of short neurites and mimicked the protein-kinase-A-dependent effect on tPA release. Such a response was not observed with K-252a, an analogue of staurosporine devoid of neurite-outgrowth-promoting activity. The responses to protein kinase A stimulation and the addition of staurosporine, although similar, seemed to occur through an activation of distinct, yet interacting, signalling pathways. In conclusion, tPA release and large neurite outgrowth from PC12 cells are controlled by parallel, albeit interacting, pathways, suggesting that these two potentially antagonistic events in PC12 cell differentiation can be modulated in a concerted way or independently of each other, depending on the activity of several protein kinases. [less ▲]

Detailed reference viewed: 43 (2 ULg)
Peer Reviewed
See detailIdentification of antigens recognized in the developing mouse brain by the RC2 antibody, a marker of radial glia
Leprince, Pierre ULg; Chanas-Sacre, G.; Wattiez, R. et al

in International Journal of Developmental Neuroscience (1996), 14(Sup. 1), 84

Detailed reference viewed: 27 (8 ULg)
Full Text
Peer Reviewed
See detailAstroglia-released factor with negative allosteric modulatory properties at the GABA A receptor.
Rigo, Jean-Michel; Belachew, Shibeshih ULg; Coucke, Paul et al

in Biochemical Pharmacology (1996), 52(3), 465-473

We have previously shown, using whole-cell patch-clamp techniques, that astrocytes release a negative allosteric modulator of the gamma-aminobutyric acid type A receptor (GABAA receptor) with beta ... [more ▼]

We have previously shown, using whole-cell patch-clamp techniques, that astrocytes release a negative allosteric modulator of the gamma-aminobutyric acid type A receptor (GABAA receptor) with beta-carboline-like properties, thus, likely to act at the benzodiazepine site. Here, using patch-clamp and binding techniques, we confirm that the low-molecular-weight fraction of astroglia-conditioned medium (ACM lmf) contains a factor(s) that negatively modulates GABAA-receptor function. This factor, like beta-carbolines, enhances the specific binding of [35S]t-butyl bicyclophosphorothionate (TBPS) to adult rat cortical membranes in the presence of GABA. However, it fails to interact with various ligands of the benzodiazepine (BZD) site of the GABAA receptor ([3H]flunitrazepam, [3H]Ro 15-1788 and [3H]Ro 15-4513). The question of the actual binding site of the astroglia-derived factor on the GABAA receptor, thus, remains open and can be addressed only after the purification of the active molecule(s) of ACM Imf has been completed, and a labeled form of the endogenous ligand becomes available. Taken together, however, the data suggest that type 1 astrocytes are able to modulate the effects of the main inhibitory neurotransmission in the central nervous system. [less ▲]

Detailed reference viewed: 61 (1 ULg)
Peer Reviewed
See detailAstroglia-Released Factor Shows Similar Effects as Benzodiazepine Inverse Agonists
Rigo, Jean-Michel; Belachew, Shibeshih ULg; LEFEBVRE, Philippe ULg et al

in Journal of Neuroscience Research (1994), 39(4), 364-76

Media conditioned by cultured neonatal cerebral cortex microexplants (CCM) or astrocytes (ACM) contain low molecular weight (< 1,000 Da) substance(s) which inhibits the gamma aminobutyric acid (GABA ... [more ▼]

Media conditioned by cultured neonatal cerebral cortex microexplants (CCM) or astrocytes (ACM) contain low molecular weight (< 1,000 Da) substance(s) which inhibits the gamma aminobutyric acid (GABA)-induced inward current recorded in cerebellar granule cells and hippocampal neurons in culture using the whole-cell patch-clamp technique. This effect is specific for CCM and ACM, as medium conditioned by PC12 cells (PC12CM) does not affect the GABA response of these cells. It is also specific for GABA-induced currents because glutamate-induced currents do not change either in amplitude or in shape in the presence of CCM or ACM. The inhibitory effect on the GABA response in cerebellar granule cells of both ACM and CCM could be suppressed by flumazenil, a specific benzodiazepine (BZD) antagonist and could be mimicked by two BZD inverse agonists. These data thus demonstrate the presence of a BZD inverse agonist-like activity in CCM and ACM. This effect of ACM on different neuronal cell types was heterogenous since no detectable effect could be observed on the GABA-induced current in GABA-responsive dorsal root ganglion (DRG) neurons, presumably reflecting a functional heterogeneity of the GABAA receptors present in these different neuronal subsets. By the release of such an endogenous BZD inverse agonist-like activity, glia cells could possibly modulate GABAA receptor-mediated responses. [less ▲]

Detailed reference viewed: 45 (5 ULg)
Peer Reviewed
See detailMetalloproteinases and serine proteases activities in mixed spheroids of mouse B16 melanoma cells and fibroblasts
Coucke, Paul; Baramova, Eugenia; Leprince, Pierre ULg et al

in International Journal of Oncology (1994), 5

Detailed reference viewed: 13 (0 ULg)
Peer Reviewed
See detailEvaluation of Matrix Metalloproteinases and Serine Proteases Activities in Three B16 Melanoma Cell Lines with Distinct Tumorigenic Potential
Baramova, E. N.; Coucke, P.; Leprince, Pierre ULg et al

in Anticancer Research (1994), 14(3A, May-Jun), 841-6

Mouse B16 melanoma cells (B16, parental line) and two derived clones either pigmented (B16P) or non pigmented (B16NP) were cultured as monolayers (2D) or on agar, as aggregates (3D). The productions of ... [more ▼]

Mouse B16 melanoma cells (B16, parental line) and two derived clones either pigmented (B16P) or non pigmented (B16NP) were cultured as monolayers (2D) or on agar, as aggregates (3D). The productions of gelatinases A and B (72 kDa and 92 kDa type IV collagenases) and their inhibitors (TIMP1 and TIMP2), plasminogen activators (PAs) and plasminogen activator inhibitors (PAI) were investigated. The B16 cell lines did not secrete any gelatinase, but they secreted TIMP2, tissue-type (t-PA), urokinase-type (u-PA) plasminogen activators and PAI-1 like activities. High levels of PAI activity were determined in conditioned media and cellular extracts of B16NP, which could account for the lower tumorigenic potential of these cells. In 3D cultures, the cellular extracts of the three cell lines contained essentially u-PA activity. This activity could contribute to the greater tumorigenic and invasive capacities of B16, B16P and B16NP when cultured in 3D. [less ▲]

Detailed reference viewed: 28 (3 ULg)
Peer Reviewed
See detailTransforming growth factor ß as a neuronoglial signal during peripheral nervous sytem response to injury.
Rogister, Bernard ULg; Delrée, P.; Leprince, Pierre ULg et al

in Journal of Neuroscience Research (1993), 34

Detailed reference viewed: 71 (27 ULg)
Full Text
Peer Reviewed
See detailPlasticity of Developing and Adult Dorsal Root Ganglion Neurons as Revealed in Vitro
Delree, P.; Ribbens, Clio ULg; Martin, Didier ULg et al

in Brain Research Bulletin (1993), 30(3-4), 231-7

We review recent data on the plasticity of dorsal root ganglion (DRG) neurons as revealed during cultivation in vitro. Some experiments on cultured developing DRG neurons and on adult DRG neurons in vivo ... [more ▼]

We review recent data on the plasticity of dorsal root ganglion (DRG) neurons as revealed during cultivation in vitro. Some experiments on cultured developing DRG neurons and on adult DRG neurons in vivo are also mentioned. Cultured developing and adult DRG neurons can be switched from an apolar to a multipolar phenotype by fetal calf serum or fibronectin. The effect is concentration dependent and occurs through an early modification of cell-substratum interaction. Adult DRG neurons synthesize and release within hours after injury TGF beta-1, which is a mitogen and a differentiation factor for Schwann cells. Finally, adult DRG neurons express in vitro neurotransmitters that are not expressed in vivo. This neurotransmitter plasticity can be modulated in vitro by some growth factors and in vivo by distal or proximal axotomy. [less ▲]

Detailed reference viewed: 39 (4 ULg)
See detailNeuronal Control of Astrocytes Proliferation
Rogister, Bernard ULg; Leprince, Pierre ULg; Martin, Didier ULg et al

in Fedoroff, S.; Juurlink, B. H. J.; Doucette, R. (Eds.) Biology and pathology of astrocyte-neuron interactions (1993)

Detailed reference viewed: 10 (5 ULg)