References of "Thiry, Marc"
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See detailOncogenic human papillomavirus could directly interact with Natural Killer cells
Renoux, Virginie; Bastin, Renaud ULg; Boniver, Jacques ULg et al

Poster (2012, May 04)

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See detailEvidence for a partial epithelial-mesenchymal transition in postnatal stages of rat auditory organ morphogenesis
Johnen, Nicolas ULg; Cloes, Marie ULg; Thelen, Nicolas ULg et al

Poster (2012, May 04)

An epithelial-mesenchymal transition is a biological process that allows a polarized epithelial cell to undergo multiple biochemical changes that enable it to assume a mesenchymal cell phenotype. During ... [more ▼]

An epithelial-mesenchymal transition is a biological process that allows a polarized epithelial cell to undergo multiple biochemical changes that enable it to assume a mesenchymal cell phenotype. During this process, epithelial cells loosen cell-cell adhesion, module their polarity and rearrange their cytoskeleton: intermediate filaments typically switch from cytokeratin to vimentin. They also enhance their motility capacity. The epithelial-mesenchymal transition plays key roles in the formation of the body plan and in the differentiation of multiple tissues and organs but it is also involved in tissue repair, tissue homeostasis, fibrosis, and carcinoma progression. Until now, epithelial-mesenchymal transition has been rarely mentioned in the inner ear organogenesis. In chick, epithelial-mesenchymal transition has been reported as a possible mechanism of semicircular canal morphogenesis. More recently, an in vitro study has also indicated that sensory epithelial cells from mouse utricle can undergo an epithelial-mesenchymal transition to become cells expressing features of prosensory cells. By contrast, epithelial-mesenchymal transition has never been observed during auditory organ morphogenesis. The auditory organ, the organ of Corti, is a highly specialized structure composed by specific cellular types. The sensory cells are characterized by stereocilia at their apex and are necessary for the sound perception. Theses cells are supported by supporting cells. Based on their morphology and physiology, at least four types of supporting cells can be identified in the organ of Corti: inner and outer pillar cells, phalangeal cell and Deiter’s cells. The inner pillar cells and outer pillar cells combine to form the tunnel of Corti, a fluid filled triangular space that separates the single row of inner hair cells from the first row of outer hair cells. The Nuel spaces are another interval in the organ of Corti that is situated between the outer pillar cells and the different rows of outer hair cells and Deiters cells. To determine whether an epithelial-mesenchymal transition may play a role in the morphogenesis of the auditory organ, we studied the spatial localization of several epithelial-mesenchymal transition markers, the cell-cell adhesion molecules and intermediate filament cytoskeletal proteins, in epithelium of the dorsal cochlea during development of the rat organ of Corti from 18th embryonic day until 25th postnatal day. We examined by confocal microscopy immunolabelings on cryosections of whole cochleae with antibodies anti-cytokeratins as well as with antibodies anti-vimentin, anti-E-cadherin and anti-beta-catenin.Our results showed a partial loss of E-cadherin and beta-catenin between supporting cells at P8 and P12, respectively, and a temporary appearance of vimentin in pillar cells and Deiters between P8 and P10. Our results show a local loss of adhesion between supporting cells of the OC from P8, an increase expression of cytokeratins in supporting cells around P10 and a temporary appearance of vimentin in supporting cells at P8-10. These observations suggest that a partial epithelial-mesenchymal transition might be involved in the remodeling of the Corti organ during the postnatal stages of development in rat. [less ▲]

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See detailNatural Killer cells - role in local tumor growth and metastasis
Langers, Inge ULg; Renoux, Virginie ULg; Thiry, Marc ULg et al

in Biologics: Targets and Therapy (2012)

Historically, the name of Natural Killer (NK) cells came from their natural ability to kill tumor cells in vitro. From the seventies to date, accumulating data highlighted the importance of NK cells in ... [more ▼]

Historically, the name of Natural Killer (NK) cells came from their natural ability to kill tumor cells in vitro. From the seventies to date, accumulating data highlighted the importance of NK cells in host immune response against cancer and in therapy-induced anti-tumor response. The recognition and the lysis of tumor cells by NK cells are regulated by a complex balance of inhibitory and activating signals. This review summarizes NK cell mechanisms to kill cancer cells, their role in host immune responses against tumor growth or metastasis and their implications in anti-tumor immunotherapies via cytokines, antibodies or in combination with other therapies. The regulatory role of NK cells in autoimmunity is also discussed. [less ▲]

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See detailImplication of HDAC-5 in heterochromatin replication
Peixoto, P; Castronovo, V; Matheus, N et al

Poster (2012)

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See detailHDAC5 depletion modulates heterochromatin plasticity and triggers programmed cell death of human cancer cells
Peixoto, P; Castronovo, V; Matheus, N et al

Poster (2012)

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See detailOncogenic human papillomavirus could directly interact with natural killer cells
Renoux, V; Bastin, R; Langers, I et al

Poster (2012)

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See detailVaricella-Zoster virus (VZV) capsids trapped in PML-bodies: antiviral defense or stress response?
Lebrun, M; Riva, L; Ote, I et al

Poster (2012)

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See detailStructure géométrique de l’ADN
Thiry, Marc ULg

Conference (2012)

L’ADN rassemble les informations nécessaires à tout organisme vivant pour survivre et se reproduire. Ce grimoire vient de ses ancêtres et sera transmis à ses descendants sous une forme légèrement remaniée ... [more ▼]

L’ADN rassemble les informations nécessaires à tout organisme vivant pour survivre et se reproduire. Ce grimoire vient de ses ancêtres et sera transmis à ses descendants sous une forme légèrement remaniée. La géométrie intervient à plusieurs stades de ce processus. [less ▲]

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See detailHDAC5 is required for maintenance of pericentric heterochromatin, and controls cell-cycle progression and survival of human cancer cells
Peixoto, Paul ULg; Castronovo, Vincenzo ULg; Matheus, Nicolas ULg et al

in Cell Death & Differentiation (2012)

Histone deacetylases (HDACs) form a family of enzymes, which have fundamental roles in the epigenetic regulation of gene expression and contribute to the growth, differentiation, and apoptosis of cancer ... [more ▼]

Histone deacetylases (HDACs) form a family of enzymes, which have fundamental roles in the epigenetic regulation of gene expression and contribute to the growth, differentiation, and apoptosis of cancer cells. In this study, we further investigated the biological function of HDAC5 in cancer cells. We found HDAC5 is associated with actively replicating pericentric heterochromatin during late S phase. We demonstrated that specific depletion of HDAC5 by RNA interference resulted in profound changes in the heterochromatin structure and slowed down ongoing replication forks. This defect in heterochromatin maintenance and assembly are sensed by DNA damage checkpoint pathways, which triggered cancer cells to autophagy and apoptosis, and arrested their growth both in vitro and in vivo. Finally, we also demonstrated that HDAC5 depletion led to enhanced sensitivity of DNA to DNA-damaging agents, suggesting that heterochromatin de-condensation induced by histone HDAC5 silencing may enhance the efficacy of cytotoxic agents that act by targeting DNA in vitro. Together, these results highlighted for the first time an unrecognized link between HDAC5 and the maintenance/assembly of heterochromatin structure, and demonstrated that its specific inhibition might contribute to increase the efficacy of DNA alteration-based cancer therapies in clinic. [less ▲]

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See detailHuman papillomavirus entry into NK cells requires CD16 expression and triggers cytotoxic activity and cytokine secretion.
Renoux, Virginie ULg; Bisig, Bettina ULg; Langers, Inge ULg et al

in European journal of immunology (2011), 41(11), 3240-3252

Human papillomavirus (HPV) infections account for more than 50% of infection-linked cancers in women worldwide. The immune system controls, at least partially, viral infection and around 90% of HPV ... [more ▼]

Human papillomavirus (HPV) infections account for more than 50% of infection-linked cancers in women worldwide. The immune system controls, at least partially, viral infection and around 90% of HPV-infected women clear the virus within two years. However, it remains unclear which immune cells are implicated in this process and no study has evaluated the direct interaction between HPVs and NK cells, a key player in host resistance to viruses and tumors. We demonstrated an NK cell infiltration in HPV-associated pre-neoplastic cervical lesions. Since HPVs cannot grow in vitro, virus-like particles (VLPs) were used as a model for studying the NK cell response against the virus. Interestingly, NK cells displayed higher cytotoxic activity and cytokine production (TNF-alpha and IFN-gamma) in the presence of HPV-VLPs. Using flow cytometry and microscopy we observed that NK cell stimulation was linked to rapid VLP entry into these cells by macropinocytosis. Using CD16(+) and CD16(-) NK cell lines and a CD16-blocking antibody, we demonstrated that CD16 is necessary for HPV-VLP internalization, as well as for degranulation and cytokine production. Thus, we show for the first time that NK cells interact with HPVs and can participate in the immune response against HPV-induced lesions. [less ▲]

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See detailDigging deeper into lymphatic vessel formation in vitro and in vivo
Detry, Benoît ULg; Bruyère, F.; Erpicum, Charlotte ULg et al

in BMC Cell Biology (2011), 12

Background Abnormal lymphatic vessel formation (lymphangiogenesis) is associated with different pathologies such as cancer, lymphedema, psoriasis and graft rejection. Lymphatic vasculature displays ... [more ▼]

Background Abnormal lymphatic vessel formation (lymphangiogenesis) is associated with different pathologies such as cancer, lymphedema, psoriasis and graft rejection. Lymphatic vasculature displays distinctive features than blood vasculature, and mechanisms underlying the formation of new lymphatic vessels during physiological and pathological processes are still poorly documented. Most studies on lymphatic vessel formation are focused on organism development rather than lymphangiogenic events occurring in adults. We have here studied lymphatic vessel formation in two in vivo models of pathological lymphangiogenesis (corneal assay and lymphangioma). These data have been confronted to those generated in the recently set up in vitro model of lymphatic ring assay. Ultrastructural analyses through Transmission Electron Microscopy (TEM) were performed to investigate tube morphogenesis, an important differentiating process observed during endothelial cell organization into capillary structures. [less ▲]

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See detailSpatio-temporal localization of the cytoskeleton during auditory organ development in mammalia
Johnen, Nicolas ULg; Thelen, Nicolas ULg; Cloes, Marie ULg et al

Poster (2011, March 31)

The auditory organ, the organ of Corti (OC), is a highly specialized structure composed by specific cellular types. The sensory cells (HC) are characterized by stereocilia at their apex and are necessary ... [more ▼]

The auditory organ, the organ of Corti (OC), is a highly specialized structure composed by specific cellular types. The sensory cells (HC) are characterized by stereocilia at their apex and are necessary for the sound perception. Theses cells are supported by supporting cells. Based on their morphology and physiology, at least four types of supporting cells (SC) can be identified in the OC: inner and outer pillar cells (PC), phalangeal cell and Deiter’s cells. Sensory and supporting cells possess characteristic cytoskeleton proteins in direct relation with their morphological features and their development. Indeed, this organ had morphological changes such as the setting up of the sensory epithelium after the birth or the openings of the Corti’s tunnel at P8 and of the Nuel’s spaces at P10. In the present study, by using confocal microscopy, we investigated the spatio-temporal localization of the three cellular cytoskeletal filaments : microtubules (β-1, 2, 3, 4-tubulin), microfilaments (cytoplasmic β- and γ-actin) and intermediate filaments (CK4, 5, 7, 8, CKpan and vimentin) during the development of the OC in rat from the embryonic day 18 (E18) to the post-natal day 25 (P25). The immunolabellings indicated clearly that β-1, 2, 3-tubulins were only present the SC and nervous fibers during development whereas β-4-tubulin was found firstly in the HC and then in the SC. The two actin-isotypes were detected in the HC apex but were also seen in the PC from P8 to P25 for β-actin isoform and in the basal membrane from E18 to P8 for the γ-actin isoform. All intermediate filament proteins were only found in the SC, especially between P8 and P12. Our results show that the localization of the cytoskeleton proteins during the auditory organ development depends on the cellular type and the developmental stage. A profound modification of cytoskeleton occurs between P8 and P12. [less ▲]

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See detailNucleolar structure across evolution : the transition between bi- and tricompartmentalized nucleoli lies within the class Reptilia
Franck, Claire; Lamaye, Françoise; Thelen, Nicolas ULg et al

Poster (2011, January 31)

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See detailSpatio-temporal localization of the glial fibrillary acidic protein (GFAP) in the spiral ganglion from the 16th embryonic day until the 25th postnatal day in rats
Cloes, Marie ULg; Thelen, Nicolas ULg; Johnen, Nicolas ULg et al

Poster (2011, January 31)

The spiral ganglion (SG) is responsible for the conduction of the information between the sensory epithelium of the auditory organ (the organ of Corti) and the central nervous system. The origin and ... [more ▼]

The spiral ganglion (SG) is responsible for the conduction of the information between the sensory epithelium of the auditory organ (the organ of Corti) and the central nervous system. The origin and nature of the SG glial cells in mammals are barely known, although glial cells are essential to the development and the working of the nervous system. Using confocal microscopy, we studied the spatio-temporal distribution of the GFAP in the rat SG from the 16th embryonic day (E16) until the 25th postnatal day (P25). We performed a double-labelling experiment targeting GFAP- and betaIIItubulin-positive cells. BetaIII-tubulin is used for the labelling of (pro)neural cells, according to a previous preliminary study from our team. Our first results show clearly that the GFAP is expressed in the SG from P0 until P25. A homogenous labelling is found in the cytoplasm of a few dispersed unidentified cells among the (pro)neurons, whereas a granular labelling appears among a group of cells neighbouring the bundle of fibers innervating the organ of Corti. The identity of the GFAP-positive cells will be further investigated by electron microscopy. The reason why the labelling of the GFAP adopts those two different aspects is still unknown. Moreover, it seems that, surprisingly, some cells of the ganglion are not labelled by either marker. The possibility that such cells correspond to fibroblasts will be tested thanks to the labelling of vimentin. [less ▲]

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See detailDistribution of glycogen during the development of the organ of Corti
Thelen, Nicolas ULg; Cloes, Marie ULg; Johnen, Nicolas ULg et al

Poster (2011, January 31)

Although the structure of the auditory organ in mature mammals, the organ of Corti, is clearly established, its development is far from being elucidated. Using cytochemical methods at the light and ... [more ▼]

Although the structure of the auditory organ in mature mammals, the organ of Corti, is clearly established, its development is far from being elucidated. Using cytochemical methods at the light and electron microscope levels, we examined the spatiotemporal distribution of polysaccharides during the development of the organ of Corti in rats from embryonic day 16 (E16) to postnatal day 15 (P15). At E16, small polysaccharide inclusions were detected in the cytoplasm of the future inner pillar cells by electron microscope only. These inclusions became obvious at the light microscope level at E17. At E19, the polysaccharide deposits were important within the inner pillar cells and they arose in the Hensen cells cytoplasm. Polysaccharide accumulations also appeared in the outer pillar cells and the Deiters cells from P3-P4. As the organ of Corti developed, the amount of polysaccharide inclusions within the inner and outer pillar cells decreased. At P15, large amount of polysaccharide deposits were visible in the Deiters cells whereas they had almost disappeared from the inner and outer pillar cells. Finally, we showed that the polysaccharide deposits present in the developing organ of Corti are PAS-positive and can be digested with a salivary amylase, suggesting that they are essentially constituted of glycogen. [less ▲]

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See detailSpatio-temporal localisation of β-actin and γ-actin isoforms during the development of the organ of Corti in rat from the embryonic day 18 (E18) to the post-natal day 25 (P25).
Johnen, Nicolas ULg; Thelen, Nicolas ULg; Cloes, Marie ULg et al

Poster (2011, January 31)

The auditory organ, the organ of Corti (OC), is a highly specialized structure composed by specific cellular types. The sensory cells (HC) are characterized by stereocilia at their apex and are necessary ... [more ▼]

The auditory organ, the organ of Corti (OC), is a highly specialized structure composed by specific cellular types. The sensory cells (HC) are characterized by stereocilia at their apex and are necessary for the sound perception. Theses cells are supported by supporting cells. Based on their morphology and physiology, at least four types of supporting cells can be identified in the OC: inner and outer pillar cells (PC), phalangeal cell and Deiter’s cells. Sensory and supporting cells have cytoskeletons containing β-actin and γ-actin isoforms. In the adult mammalian cochlea, amounts of γ-actin increase and β-actin decrease in the order: outer pillar cells, inner pillar cells, Deiters’ cells and hair cells. In sensory cells, γ-actin appears to be the most prominent component with an apparent γ-actin/β-actin ratio of approximately 2:1 (Hofer et al., 1997). β-actin is present in the cuticular plate but is more concentrated in the stereocilia, especially at the base where the stereocilia insert into the cuticular plate. The amount of γ-actin differs less between these structures, the stereocilia and cuticular plate, although its expression is apparently higher towards the tip of stereocilia and it is the predominant isoform of the hair cell's lateral wall (Furness et al., 2005). The differential subcellular localization of two actin isoforms suggests they may play different functions in auditory organ. In the brain, β-actin is restricted to dynamic structures whereas γ-actin is more ubiquitously distributed and occurs in relatively quiescent regions (Micheva et al., 1998). In the present study, by using confocal microscopy, we investigated the spatio-temporal localisation of β-actin and γ-actin isoforms during the development of the OC in rat from the embryonic day 18 (E18) to the post-natal day 25 (P25). Our results indicated that the labelling for both actin isoforms changed during the OC development. Between E18 and P25, we observed a labelling for β-actin in the apical region of the HC. Between P8 and P25, the feet of PC are also β-actin-positive. Unlike β-actin, between E18 and P10, γ-actin is detected in the basal region of supporting cells. Between P12 and P25, the labelling for γ-actin is preferentially localized in the apical surface of the HC. Our results revealed that during development β-actin isoform preceded γ-actin isoform in the apical region of HC. They also suggest that γ-actin isoform might be involved in attachment of supporting cells with their basal membrane and that β-actin isoform might play a role in PC reorganization during the formation of Corti tunnel. [less ▲]

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