References of "Gillet, Marie-Claire"
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See detailDevelopment of a strategy to study toxicodynamic of pollutants in spawning sea turtles from the French West Indies
Dyc, Christelle ULg; Bouquegneau, Jean-Marie ULg; Gillet, Marie-Claire ULg et al

Poster (2008, October)

Sea turtles including the green turtle Chelonia mydas and the hawksbill turtle Eretmochelys imbricata are critically endangered species, facing different factors as marine pollution. There is a blatant ... [more ▼]

Sea turtles including the green turtle Chelonia mydas and the hawksbill turtle Eretmochelys imbricata are critically endangered species, facing different factors as marine pollution. There is a blatant lack of data dealing with toxicants such as metals and persistent organic pollutants (POPs) in sea turtles. We developed a strategy to apprehend levels, effects and transfer to offspring of several pollutants in sea turtles. Sampling of blood, subcutaneous tissue and eggs of 15 gravid C. mydas and E. imbricata was carried out between July and September 2008 in Martinique (Diamant’s beach) and Guadeloupe (Petite Terre and Marie-Galante). Blood was collected from the dorso-cervical sinus and subcutaneous tissue was sampled in shoulder of the spawning females using a 5 mm biopsy punch (Kai Europe GmbH, Germany). Total blood and serum were successfully taken for metal, POP and biomarker investigations. T-mercury was analyzed by DMA milestones while PCBs, DDT and chlordecone were analyzed by EDC Ni63 high performance gas chromatography HPLC. Samples of serum were analyzed for vitamins (A and E) by HPLC and for thyroid hormones (triiodothyronine and thyroxine) by radioimmunoassay. In parallel to this field study, a cell model using 3T3-L1 cell line was built up to test in vitro effects of PCBs and mercury as well as the relationship between in vitro exposure and fat mobilization. Preliminary results showed a dose-response relationship between increased Aroclor 1234 and 1252 concentrations (0.5 ppb, 1 ppb and 1.5 ppb) and adipocyte mortality (Nucleocounter). The strategy we propose here will bring further insights on levels and potential impact of pollutants on female sea turtles and their offspring. [less ▲]

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See detailImparting antifouling properties of poly(2-hydroxyethyl methacrylate) hydrogels by grafting poly(oligoethylene glycol methyl ether acrylate)
Bozukova, Dimitriya ULg; Pagnoulle, Christophe; Gillet, Marie-Claire ULg et al

in Langmuir (2008), 24(13), 6649-6658

The antifouling properties of poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) hydrogels were improved by the surface grafting of a brush of poly(oligoethylene glycol methyl ether acrylate) [poly ... [more ▼]

The antifouling properties of poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) hydrogels were improved by the surface grafting of a brush of poly(oligoethylene glycol methyl ether acrylate) [poly(OEGA)]. The atom-transfer radical polymerization (ATRP) of OEGA (degree of polymerization = 8) was initiated from the preactivated surface of the hydrogel under mild conditions, thus in water at 25 °C. The catalytic system was optimized on the basis of two ligands [1,1,4,7,10,10-hexamethyl-triethylenetetramine (HMTETA) or tris[2-(dimethylamino)ethyl]amine (Me6TREN)] and two copper salts (CuIBr or CuICl). Faster polymerization was observed for the Me6TREN/CuIBr combination. The chemical composition and morphology of the coated surface were analyzed by X-ray photoelectron spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy, contact angle measurements by the water droplet and captive bubble methods, scanning electron microscopy, and environmental scanning electron microscopy. The hydrophilicity of the surface increased with the molar mass of the grafted poly(OEGA) chains, and the surface modifications were reported in parallel. The antifouling properties of the coatings were tested by in vitro protein adsorption and cell adhesion tests, with green fluorescent protein, β-lactamase, and lens epithelial cells, as model proteins and model cells, respectively. The grafted poly(OEGA) brush decreased the nonspecific protein adsorption and imparted high cell repellency to the hydrogel surface. [less ▲]

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See detailSurface coating of hydrogel intraocular lenses toward resistance to posterior capsular opacification
Bozukova, Dimitriya; Pagnoulle, Christophe; Gillet, Marie-Claire ULg et al

Conference (2008, May 23)

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See detailProteome alteration induced by hTERT transfection of human fibroblast cells
Mazzucchelli, Gabriel ULg; Gabelica, Valérie ULg; Smargiasso, Nicolas ULg et al

in Proteome Science (2008), 6(1), 12

Background: Telomerase confers cellular immortality by elongating telomeres, thereby circumventing the Hayflick limit. Extended-life-span cells have been generated by transfection with the human ... [more ▼]

Background: Telomerase confers cellular immortality by elongating telomeres, thereby circumventing the Hayflick limit. Extended-life-span cells have been generated by transfection with the human telomerase reverse transcriptase (hTERT) gene. hTERT transfected cell lines may be of outstanding interest to monitor the effect of drugs targeting the telomerase activity. The incidence of hTERT gene transfection at the proteome level is a prerequisite to that purpose. The effect of the transfection has been studied on the proteome of human fibroblast (W138). Cytosolic and nuclear fractions of W138 cells, empty vector transfected W138 (W138-HPV) and hTERT W138 cells were submitted to a 2D-DIGE (Two-Dimensional Differential In-Gel Electrophoresis) analysis. Only spots that had a similar abundance in W138 and W138-HPV, but were differentially expressed in W138 hTERT were selected for MS identification. This method directly points to the proteins linked with the hTERT expression. Number of false positive differentially expressed proteins has been excluded by using control W138-HPV cells. The proteome alteration induced by hTERT W138 transfection should be taken into account in subsequent use of the cell line for anti-telomerase drugs evaluation. Results: 2D-DIGE experiment shows that 57 spots out of 2246 are significantly differentially expressed in the cytosolic fraction due to hTERT transfection, and 38 were confidently identified. In the nuclear fraction, 44 spots out of 2172 were selected in the differential proteome analysis, and 14 were identified. The results show that, in addition to elongating telomeres, hTERT gene transfection has other physiological roles, among which an enhanced ER capacity and a potent cell protection against apoptosis. Conclusion: We show that the methodology reduces the complexity of the proteome analysis and highlights proteins implicated in other processes than telomere elongation. hTERT induced proteome changes suggest that telomerase expression enhances natural cell repair mechanisms and stress resistance probably required for long term resistance of immortalized cells. Thus, hTERT transfected cells can not be only consider as an immortal equivalent to parental cells but also as cells which are over-resistant to stresses. These findings are the prerequisite for any larger proteomics aiming to evaluate anti-telomerase drugs proteome alteration and thus therapeutics induced cell reactions. [less ▲]

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See detailLNCaP prostate cancer imaging with biologically functionalized gold nanoparticles in 2D and 3D cell culture
Schol, Daureen ULg; Fleron, Maximilien ULg; Greisch, Jean - François et al

in Anticancer Research (2008), 28

One of the main objectives of this project is to realize and validate a versatile lab system composed of functionalized nanoparticles for diagnosis of different superficial and accessible cancers, e.g ... [more ▼]

One of the main objectives of this project is to realize and validate a versatile lab system composed of functionalized nanoparticles for diagnosis of different superficial and accessible cancers, e.g. prostate cancer. Gold nanorods have been synthesized and functionalized with antibodies targeting specific antigens on cancer cell lines. [less ▲]

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See detailPores formation on cell membranes by hederacolchiside A1 leads to a rapid release of proteins for cytosolic subproteome analysis
Mazzucchelli, Gabriel ULg; Cellier, Nicolas A; Mshviladzade, Vakhtang et al

in Journal of Proteome Research (2008), 7(4), 1683-1692

Hederacolchiside A1 was used to progressively permeabilize the membrane of human melanoma MEL-5 cells. Holes formation was followed by Scanning Electron Microscopy and interaction of the saponin with ... [more ▼]

Hederacolchiside A1 was used to progressively permeabilize the membrane of human melanoma MEL-5 cells. Holes formation was followed by Scanning Electron Microscopy and interaction of the saponin with cholesterol and phospholipids by TOF-SIMS. 2D-LC-MS/MS and 2D-SDS-PAGE show that the release of soluble proteins into serum-free culture media increases with time. This can lead to a new rapid and efficient strategy to analyze the cytosolic subproteome and it opens the door to get information from the cytosolic compartment for clinical proteomic studies. [less ▲]

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See detailProteomic analysis of telomerase inhibition by telomere specific ligands
Mazzucchelli, Gabriel ULg; Gabelica, Valérie ULg; Smargiasso, Nicolas ULg et al

in Anticancer Research (2008), 28(5c), 3257-3258

Telomeres consist of protein complexes and repeated ‘TTAGGG’ double strand DNA sequences ended by a 3’ single strand DNA of the same sequence. Progressive telomere shortening is observed in vitro upon ... [more ▼]

Telomeres consist of protein complexes and repeated ‘TTAGGG’ double strand DNA sequences ended by a 3’ single strand DNA of the same sequence. Progressive telomere shortening is observed in vitro upon cell divisions and with ageing in vivo. At a critical telomere length, shortened telomeres trigger a permanent growth arrest known as replicative senescence. Telomerase is an RNA-dependent DNA polymerase that extends telomeres by adding ‘TTAGGG’ repeats. It consists of a functional RNA component (hTR) which serves as template and a catalytic protein (hTERT) with reverse transcriptase activity. The expression of hTERT alone is sufficient for the immortalisation of cells. Telomerase is highly expressed in tumor cells but at very low level in most somatic cells. These observations make the telomerase an attractive target for anticancer strategies. One of these strategies relies on the use of drug candidates able to stabilize the particular telomere G-quadruplex DNA structures. The stabilization of these structures makes the telomere inaccessible for telomerase and thus inhibits telomerase activity. The effect of the hTERT transfection was first studied on the proteome of human WI38 fibroblast cells (1). Then, the proteome alteration response of hTERT transfected WI38 cells induced by the treatment of two G-quadruplexes ligands, telomestatin and TMPyP4, was analyzed. Both compounds can inhibit telomerase but have different selectivity for the different G-quadruplexes structures. Proteome analysis of the treated cells reveals that TMPyP4 induces much more protein expression alterations than telomestatin probably due to its poor selectivity. TMPyP4 induces especially a drastic down expression of the hnRNPs, a modulation of the proteasome pathway, an apparent decrease of the translation and an over expression of several molecular chaperones. Telomestatin induces in particular an over expression of the protein BCL2A1 which is involved in drug resistance of cancer cells and a probable increase of the translation. Both treatments have a common effect particularly on the molecular chaperone CCT (down expression), HSP90 alpha (over expression) and hnRNP D (down expression). The protein HSP90 alpha is also over expressed in hTERT transfected cells compared to parental cells. This protein is already a promising anticancer target protein due to its central role in oncogenesis and in telomerase activity regulation. 1 Mazzucchelli et al: Proteome Science 6: 12, 2008. [less ▲]

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See detailMercury immune toxicity in harbour seals: Links to in vitro toxicity
Das, Krishna ULg; Siebert, Ursula; Gillet, Audrey et al

in Environmental Health : A Global Access Science Source (2008), 7

Background Mercury is known to bioaccumulate and to magnify in marine mammals, which is a cause of great concern in terms of their general health. In particular, the immune system is known to be ... [more ▼]

Background Mercury is known to bioaccumulate and to magnify in marine mammals, which is a cause of great concern in terms of their general health. In particular, the immune system is known to be susceptible to long-term mercury exposure. The aims of the present study were (1) to determine the mercury level in the blood of free-ranging harbour seals from the North Sea and (2) to examine the link between methylmercury in vitro exposure and immune functions using seal and human mitogen-stimulated peripheral blood mononuclear cells (T-lymphocytes). Methods Total mercury was analysed in the blood of 22 harbour seals. Peripheral blood mononuclear cells were isolated from seals (n = 11) and from humans (n = 9). Stimulated lymphocytes of both species were exposed to functional tests (proliferation, metabolic activity, radioactive precursor incorporation) under increasing doses of methylmercury (0.1 to 10 µM). The expression of cytokines (IL-2; IL-4 and TGF-beta was investigated in seal lymphocytes by RT-PCR and by real time quantitative PCR (n = 5) at methylmercury concentrations of 0.2 and 1 µM. Finally, proteomics analysis was attempted on human lymphocytes (cytoplasmic fraction) in order to identify biochemical pathways of toxicity at concentration of 1 µM (n = 3). Results The results showed that the number of seal lymphocytes, viability, metabolic activity, DNA and RNA synthesis were reduced in vitro, suggesting deleterious effects of methylmercury concentrations naturally encountered in free-ranging seals. Similar results were found for human lymphocytes. Functional tests showed that a 1 µM concentration was the critical concentration above which lymphocyte activity, proliferation and survival were compromised. The expression of IL-2 and TGF-beta mRNA was weaker in exposed seal lymphocytes compared to control cells (0.2 and 1 µM). Proteomics showed some variation in the protein expression profile (e.g. vimentin). [less ▲]

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See detailDevelopment of an in vitro model for mercury exposure in marine mammals
Dupont, Aurélie ULg; Bouquegneau, Jean-Marie ULg; Siebert, Ursula et al

Poster (2007, November 01)

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See detailImproved performances of intraocular lenses by poly(ethylene glycol) chemical coatings
Bozukova, Dimitriya ULg; Pagnoulle, Christophe; Gillet, Marie-Claire ULg et al

in Biomacromolecules (2007), 8(8), 2379-2387

Cataract surgery is a routine ophthalmologic intervention resulting in replacement of the opacified natural lens by a polymeric intraocular lens (IOL). A main postoperative complication, as a result of ... [more ▼]

Cataract surgery is a routine ophthalmologic intervention resulting in replacement of the opacified natural lens by a polymeric intraocular lens (IOL). A main postoperative complication, as a result of protein adsorption and lens epithelial cell (LEC) adhesion, growth, and proliferation, is the secondary cataract, referred to as posterior capsular opacification (PCO). To avoid PCO formation, a poly(ethylene glycol) (PEG) chemical coating was created on the surface of hydrogel IOLs. Attenuated total reflectance Fourier transform infrared spectroscopy, “captive bubble” and “water droplet” contact angle measurements, and atomic force microscopy analyses proved the covalent grafting of the PEG chains on the IOL surface while keeping unchanged the optical properties of the initial material. A strong decrease of protein adsorption and cell adhesion depending on the molar mass of the grafted PEG (1100, 2000, and 5000 g/mol) was observed by performing the relevant in vitro tests with green fluorescent protein and LECs, respectively. Thus, the study provides a facile method for developing materials with nonfouling properties, particularly IOLs. [less ▲]

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See detailApoptosis and cytolysis induced by giganteosides and hederacolchisides in HL-60 cells
Gerkens, Pascal; Dobson, Rowan ULg; tabatadze, Nino et al

in Anticancer Research (2007), 27

The viability, cytolysis and apoptosis-mediated cellular death induced by giganteosides D and E (Gig-D and Gig-E) and hederacolchisides A and A1 (Hcol-A and Hcol- A1) were analysed in HL-60 cells ... [more ▼]

The viability, cytolysis and apoptosis-mediated cellular death induced by giganteosides D and E (Gig-D and Gig-E) and hederacolchisides A and A1 (Hcol-A and Hcol- A1) were analysed in HL-60 cells. Materials and Methods: the end-point metabolic (WST1) and lactate dehydrogenase (LDH) assays were used. Cell cycle analysis and apoptosis were measured by flow cytometry, DNA laddering and caspase 3 analyses. Results: the HL-60 cell line was more sensitive to Hcol-A1 and Gig-D (IC50 3-5 ÌM) than to Gig-E and Hcol-A (IC50 8-13 ÌM; WST1 assay). This was related to LDH release. The induction of apoptosis could be detected without caspase 3 activation after 24 h of treatment. DNA fragmentation could be detected only with Gig-D. With Hcol- A1 and Gig-D, an accumulation of cells in the S-phase and an increase of cells in sub-G1 peak were observed. By the annexinV-fluorescein isothiocyanate (FITC)/7-aminoactinomycin D (AAD) assay, the majority of cells were in late apoptosis with Gig-D, and in necrosis with Hcol-A1. Conclusion: Hcol-A1 is more cytotoxic than Gig-D, followed by Gig-E and finally Hcol-A. This is related to a membrane permeabilization effect, leading to cytolysis [less ▲]

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See detailGlobal strategy for the development of estrogenic compounds detection screening test
Collodoro, Mike ULg; Makasinga, Elu; Lemaire, Pascale ULg et al

Poster (2007, May)

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See detailCytotoxic triterpenoid saponins from the roots of Cephalaria gigantea
Tabatadze, Nino; Elias, Riad; Faure, Robert et al

in Chemical & Pharmaceutical Bulletin (2007), 55(1), 102-105

Three new oleanane-type saponins, giganteosides L (1)(I), M (2) and N (3) along with eight known ones were isolated from the roots of Cephalaria gigantea. Their structures were established as 3-O-[-D ... [more ▼]

Three new oleanane-type saponins, giganteosides L (1)(I), M (2) and N (3) along with eight known ones were isolated from the roots of Cephalaria gigantea. Their structures were established as 3-O-[-D-galactopyranosyl-(12)--D-glucuronopyranosyl]-28-O-[-D-glucopyranosyl-(16)--D-glucopyranosyl]-oleanolic acid, 3-O-[-D-galactopyranosyl-(12)--D-glucuronopyranosyl]-28-O-[-D-glucopyranosyl-(16)--D-glucopyranosyl]-hederagenin, 3-O-[-L-rhamnopyranosyl-(12)--D-glucuronopyranosyl]-28-O-[-D-glucopyranosyl-(16)--D-glucopyranosyl]-hederagenin, resp., by means of spectroscopic methods (1D and 2D NMR, HR-ESI-MS). Cytotoxic activity of monodesmosides was investigated in vitro using three cancer cell lines, namely, human non pigmented melanoma MEL-5 and human leukemia HL-60. Giganteosides D (4) and E (5) showed antiproliferative effect on human cell lines with IC50 values in the range 3.15-7.5 M. [less ▲]

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See detailMG-63 Osteoblast culture on P culture on PLA– based copolymers for bone tissue engineering applications
Moniotte, Nicolas; Shim, Yong-Ho; Borget, Pascal et al

Poster (2007)

Physical injury or pathological changes such as removal of a tumor can result in large bone defects, preventing the recovery of its original function. Autogenous bone grafting, which is the most common ... [more ▼]

Physical injury or pathological changes such as removal of a tumor can result in large bone defects, preventing the recovery of its original function. Autogenous bone grafting, which is the most common technique for bone defect repairing, is associated with serious limitations, e.g. limited supply and donor site morbidity. Since a few years bone tissue engineering by degradable biomaterials has been shown as a very promising avenue for providing bone substitutes. Among these materials, bioresorbable synthetic polymers such as poly(ethylene oxide) (PEO), poly(vinyl alcohol) (PVA), poly(acrylic acid) (PAA) and poly(lactic acid) (PLA) are very appealing because their chemistry and properties are controllable and reproducible. Cellular activity and proliferation of osteosarcoma cell lines (MG-63) on films were determined by the tetrazolium salt MTT assay and by phase contrast/fluorescence microscope observations. The cytotoxicity of the materials was found to be low or negligible. Cells viability variations were observed on the surface of the films. Long-term cell culture and degradability of PLA-PEOpolymer film was investigated by optical microscopy (Giemsa staining) and environmental scanning electron microscopy (ESEM). Hydrolysis of the PLLA ester linkages led to slow film degradation. After 113 days, optical microscope observations revealed the presence of large cracks on the surface, and even breaks of small polymer fragments, while MG-63 proliferation was still very important, showing a tissue-like aspect, with extracellular matrix (ECM) deposition. These results show that PLA-PEO copolymers are very interesting bioresorbable materials for long-term bone tissue engineering applications. [less ▲]

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See detailMG-63 Osteoblast Culture on Biodegradable Textiles for Bone Tissue Regeneration
Moniotte, Nicolas; Borget, Pascal; Pirotte, Fabrice et al

Poster (2007)

The primary aim of bone scaffold is to restore, maintain and improve the structure and properties of damaged bones. The scaffold acts as a 3-D template for guided tissue-engineering and provides an ... [more ▼]

The primary aim of bone scaffold is to restore, maintain and improve the structure and properties of damaged bones. The scaffold acts as a 3-D template for guided tissue-engineering and provides an excellent transition from in vitro to in vivo systems, avoiding auto- or allo-grafting treatments, both associated with serious limitations. The pore size of the scaffold must be large enough to allow cell migration and proliferation through the structure, but small enough to provide sufficient specific area for cell attachment. In this work, degradable poly(lactic acid) (PLA) yarns were knitted into complexes superstructures and evaluated as 3-D scaffold to promote cell bone reconstruction. PLA fabrics were knitted from multi-filaments in a double layer interlock structure to produce a weft knit. The fabrics are made of two porosities, one defined by the open space inside a loop (~1mm) and the second by the distance between the filaments (1-10 µm), with high control and reproducibility inherent to the manufacturing process. Human MG-63 osteoblast-like cells were seeded on PLA textiles and cell viability and proliferation were evaluated using MTS (tetrazolium salt) assays, DNA quantitative analysis (hoechst), fluorescence staining (acridine orange) and scanning electron microscopy. Alkaline Phosphatase activity in cell lysates was also investigated. After 3 days of culture, MG-63 fully expressed their fibroblastic phenotype. Although the number of cells was high, mitochondrial activity was shown to be reduced when cells are on the PLA fibres (compared to culture on a glass slide). This may be due the release of lactic acid by slow hydrolysis of PLA ester-bonds. Only a small population of cells was dead. Furthermore, it could be due to cells in a less active phase, such as cells entering the G0 phase, or in a maturing phase. From 6 to 12 days, the number of cell inside the PLA fabrics increased and typical fibroblastic morphology was maintained. Cells were mainly observed in the spaces between fibres. After 24 days of culture, MG-63 colonization is covering all the PLA knit. Small granular structures are present on the cell surface and low ALP concentration is detected, indicating the beginning of the differentiation process, rather than a toxic effect of PLA hydrolysis. This work shows that knitted PLA fabrics, seeded with autogeneous osteoblast cells can potentially be used as tissue-engineered implants for the treatment of bone defects. [less ▲]

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