References of "Colige, Alain"
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See detailPreparation and characterizations of EGDE crosslinked chitosan electrospun membranes
Aqil, Abdelhafid ULg; Tchemtchoua, Victor T.; Colige, Alain ULg et al

in Clinical Hemorheology and Microcirculation (in press)

Composite Crosslinked nanofibrous membranes of chitosan, ethylene glycol diglycidyl ether (EGDE) and polyethy- 10 lene oxide was successfully prepared with bead free morphology via electrospinning ... [more ▼]

Composite Crosslinked nanofibrous membranes of chitosan, ethylene glycol diglycidyl ether (EGDE) and polyethy- 10 lene oxide was successfully prepared with bead free morphology via electrospinning technique followed by heat mediated 11 chemical crosslinking. Architectural stability of nanofiber mat in aqueous medium was achieved by chemical crosslinking of 12 only 1% EGDE, and tensile strength tests revealed that increasing EGDE content has considerably enhance the elastic modu- 13 lus of nanofibers. The structure, morphology and mechanical properties of nanofibers were characterized by Attenuated Total 14 Reflection-Fourier Transform Infrared spectroscopy (ATR–FTIR), scanning electron microscopy (SEM) and Instron machine, 15 respectively. Skin fibroblasts and endothelial cells showedgood attachment, proliferation and viability on crosslinked electrospun 16 membranes. The results indicate a good biocompatibility and non-toxic nature of the resulted membrane. [less ▲]

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See detailLipin-1 regulates cancer cell phenotype and is a potential target to potentiate rapamycin treatment
Brohée, Laura ULg; Demine, Stéphane; Willems, Jérôme ULg et al

in Oncotarget (2015), 6(13), 11264-11280

Lipogenesis inhibition was reported to induce apoptosis and repress proliferation of cancer cells while barely affecting normal cells. Lipins exhibit dual function as enzymes catalyzing the ... [more ▼]

Lipogenesis inhibition was reported to induce apoptosis and repress proliferation of cancer cells while barely affecting normal cells. Lipins exhibit dual function as enzymes catalyzing the dephosphorylation of phosphatidic acid to diacylglycerol and as co-transcriptional regulators. Thus, they are able to regulate lipid homeostasis at several nodal points. Here, we show that lipin-1 is up-regulated in several cancer cell lines and overexpressed in 50 % of high grade prostate cancers. The proliferation of prostate and breast cancer cells, but not of non-tumorigenic cells, was repressed upon lipin-1 knock-down. Lipin-1 depletion also decreased cancer cell migration through RhoA activation. Lipin-1 silencing did not significantly affect global lipid synthesis but enhanced the cellular concentration of phosphatidic acid. In parallel, autophagy was induced while AKT and ribosomal protein S6 phosphorylation were repressed. We also observed a compensatory regulation between lipin-1 and lipin-2 and demonstrated that their co-silencing aggravates the phenotype induced by lipin-1 silencing alone. Most interestingly, lipin-1 depletion or lipins inhibition with propranolol sensitized cancer cells to rapamycin. These data indicate that lipin-1 controls main cellular processes involved in cancer progression and that its targeting, alone or in combination with other treatments, could open new avenues in anticancer therapy. [less ▲]

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See detailStudy of a new splice variant of Neuropilin-1: antagonistic functions in the regulation of cancer progression?
Hendricks, Céline ULg; Janssen, Lauriane; Delcombel, Romain et al

Poster (2015, April 22)

Neuropilin-1 (NRP1) is a transmembrane glycoprotein and a co-receptor for several growth factors, for example some variants of the Vascular Endothelial Growth Factor A (VEGF-A). It largely contributes to ... [more ▼]

Neuropilin-1 (NRP1) is a transmembrane glycoprotein and a co-receptor for several growth factors, for example some variants of the Vascular Endothelial Growth Factor A (VEGF-A). It largely contributes to the regulation of angiogenesis but also to cancer formation. NRP1 can be considered as a proteoglycan as glycosaminoglycans side chains can be added on serine 612. Currently, six splice variants of NRP1 have been described. An additional form was recently identified in our laboratory. Depending upon the cell types, it represents 20-30% of the total amount of NRP1. As compared to the full size NRP1 (NRP1-FS), 7 amino acids are deleted. As the missing sequence is located 2 amino acids downstream of the Ser612 required for glycosaminoglycans addition, this process could be somehow affected and the function of the protein could be modified. The glycosylation of NRP1-FS and -Δ7 was analyzed in different cells overexpressing each isoform. Western blotting analyses suggested that NRP1-Δ7 was less glycosylated than NRP1-FS. Prostate cancer cells (PC3) were engineered to express NRP1-FS or –Δ7 only in the presence of doxycycline. The migration of these cells was analyzed by scratch assay, with or without doxycycline in the medium. As compared to controls and to NRP1-FS-expressing cells, production of NRP1-Δ7 was linked to a reduction of cell migration. A DNA dosage showed that NRP1-FS enhanced cell proliferation, while NRP1-Δ7 reduced it. Tumor growth was assessed in vitro by a culture in soft agar. As compared to control conditions, expression of NRP1-FS by doxycycline increased colonies formation. By contrast, NRP1-Δ7 inhibited colonies number, suggesting an inhibition of tumorigenesis by this variant. As PC3 cells express basal level of endogenous NRP1, this suggests some competitive inhibition of NRP1 functions by NRP1-Δ7. Finally, the function of each variant was investigated in vivo in a model of injection in the flanks of nude mice of PC3 cells conditionally expressing NRP1-FS or -Δ7. As compared to the control, NRP1-FS increased tumor size and weight. By sharp contrast, the expression of NRP1-Δ7 was associated with a reduction of tumorigenicity. Cells with forced expression of NRP1-Δ7 also developed fewer blood vessels as compared to the control. These results suggest that NRP1-Δ7 have an antagonistic action on cancer formation and angiogenesis. [less ▲]

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See detailPlasma riche en plaquettes et lésions tendineuses
KAUX, Jean-François ULg; Drion, Pierre ULg; Croisier, Jean-Louis ULg et al

in Revue Médicale de Liège (2014), 69(Synthèse 2014), 72-77

Platelets contain growth factors released during their degranulation following activation. These growth factors promote tissue remodeling, wound healing and angiogenesis. Currently, the clinical effect of ... [more ▼]

Platelets contain growth factors released during their degranulation following activation. These growth factors promote tissue remodeling, wound healing and angiogenesis. Currently, the clinical effect of Platelet-Rich Plasma (PRP) is still discussed or even controversial. Our researches have evaluated the effectiveness of PRP on the healing of animal tendons and human suffering from chronic jumper's knee. [less ▲]

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See detailRac1 GTPase silencing counteracts microgravity-induced effects on osteoblastic cells.
Guignandon, Alain; Fauré, Céline; Neutelings, Thibault et al

in FASEB Journal (2014), 28(9), 4077-4087

Bone cells exposed to real microgravity display alterations of their cytoskeleton and focal adhesions, two major mechanosensitive structures. These structures are controlled by small GTPases of the Ras ... [more ▼]

Bone cells exposed to real microgravity display alterations of their cytoskeleton and focal adhesions, two major mechanosensitive structures. These structures are controlled by small GTPases of the Ras homology (Rho) family. We investigated the effects of RhoA, Rac1, and Cdc42 modulation of osteoblastic cells under microgravity conditions. Human MG-63 osteoblast-like cells silenced for RhoGTPases were cultured in the automated Biobox bioreactor (European Space Agency) aboard the Foton M3 satellite and compared to replicate ground-based controls. The cells were fixed after 69 h of microgravity exposure for postflight analysis of focal contacts, F-actin polymerization, vascular endothelial growth factor (VEGF) expression, and matrix targeting. We found that RhoA silencing did not affect sensitivity to microgravity but that Rac1 and, to a lesser extent, Cdc42 abrogation was particularly efficient in counteracting the spaceflight-related reduction of the number of focal contacts [-50% in silenced, scrambled (SiScr) controls vs. -15% for SiRac1], the number of F-actin fibers (-60% in SiScr controls vs. -10% for SiRac1), and the depletion of matrix-bound VEGF (-40% in SiScr controls vs. -8% for SiRac1). Collectively, these data point out the role of the VEGF/Rho GTPase axis in mechanosensing and validate Rac1-mediated signaling pathways as potential targets for counteracting microgravity effects [less ▲]

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See detailPhysical, chemical and cyctotoxi properties of cross-linked chitosan electrospun fiber mats
Aqil, Abdelhafid ULg; Tchemtchoua, Victor T.; Colige, Alain ULg et al

Poster (2014, May)

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See detailVascular Endothelial Growth Factor-111 (VEGF-111) and tendon healing: preliminary results in a rat model of tendon injury
Kaux, Jean-François ULg; Janssen, Lauriane ULg; Drion, Pierre ULg et al

in Muscles, Ligaments and Tendons Journal (2014), 4(1 (eCollection 2014 Jan)), 25-28

Tendon lesions are among the most frequent musculoskeletal pathologies. Vascular endothelial growth factor (VEGF) is known to regulate angiogenesis. VEGF-111, a biologically active and proteolysis ... [more ▼]

Tendon lesions are among the most frequent musculoskeletal pathologies. Vascular endothelial growth factor (VEGF) is known to regulate angiogenesis. VEGF-111, a biologically active and proteolysis-resistant splice variant of this family, was recently identified. This study aimed at evaluating whether VEGF-111 could have a therapeutic interest in tendon pathologies. Surgical section of one Achilles tendon of rats was performed before a local injection of either saline or VEGF-111. After 5, 15 and 30 days, the Achilles tendons of 10 rats of both groups were sampled and submitted to a biomechanical tensile test. The force necessary to induce tendon rupture was greater for tendons of the VEGF-111 group (p<0.05) while the section areas of the tendons were similar. The mechanical stress was similar at 5 and 15 days in the both groups but was improved for the VEGF-111 group at day 30 (p <0.001). No difference was observed in the mRNA expression of collagen III, tenomodulin and MMP-9. In conclusion, we observed that a local injection of VEGF-111 improves the early phases of the healing process of rat tendons after a surgical section. Further confirmatory experimentations are needed to consolidate our results. [less ▲]

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See detailEccentric training improves tendon biomechanical properties: a rat model
Kaux, Jean-François ULg; Drion, Pierre ULg; Libertiaux, Vincent et al

in British Journal of Sports Medicine (2014, April), 48(7), 155

Background: Even if eccentric exercises appear favourable in primary prevention of tendons lesions and, especially, in secondary prevention after tendinopathy, the biomechanical changes to the tissue are ... [more ▼]

Background: Even if eccentric exercises appear favourable in primary prevention of tendons lesions and, especially, in secondary prevention after tendinopathy, the biomechanical changes to the tissue are not yet clear. Objective: We aimed to better define the biomechanical changes that affect healthy tendon after eccentric and concentric training. Design: Randomised controlled trial. Participants: Eighteen Sprague-Dawley rats of 2 months. Interventions: The six rats in the control group (U) were not subjected to physical exercise. The 12 remaining rats (6 in each group) ran on a treadmill set at a +15° incline for concentric training (C) or a -15° incline for eccentric training (E), at a speed of 17 m/min for 1 h, three times per week for 5 weeks. Main Outcome Measurements: The tricipital, patellar and Achilles tendons were subsequently removed to perform a traction test until rupture, and a histological analysis was performed. Results: There was a significant improvement in the rupture force of the patellar and tricipital tendons between the U and E groups. The tricipital tendons in the control group presented a significantly smaller cross-section than the E- and C-trained groups, but none between E and C groups. No significant difference was observed for the mechanical stress at rupture per surface unit between the three groups for all three tendons. However, a tendency towards improvement these values was observed between the trained and the U groups for the patellar tendon. Histological studies demonstrated the tendency of the development of a greater number of blood vessels and a larger quantity of collagen in the eccentric group. Conclusions: The mechanical properties of tendons in rats improve after specific training, especially following eccentric training. Our results partly explained how mechanical loading, especially in eccentric mode, could improve the tendon structure. [less ▲]

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See detailTgfbeta-Smad and MAPK signaling mediate scleraxis and proteoglycan expression in heart valves.
Barnette, Damien; Hulin, Alexia; Ahmed, Ishtiaq et al

in Journal of Molecular and Cellular Cardiology (2013), 65

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See detailADAMTS-3 deficiency is embryonic lethal in mouse and zebrafish.
Janssen, Lauriane ULg; Dubail, Johanne; Dupont, Laura ULg et al

Conference (2013, November)

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See detail18F-FDG Uptake Assessed by PET/CT in Abdominal Aortic Aneurysms Is Associated with Cellular and Molecular Alterations Prefacing Wall Deterioration and Rupture.
Courtois, Audrey ULg; Richelle, Betty ULg; Hustinx, Roland ULg et al

in Journal of Nuclear Medicine (The) (2013), 54

Rupture of abdominal aortic aneurysms (AAAs) leads to a significant morbidity and mortality in aging populations, and its prediction would be most beneficial to public health. Spots of positive uptake of ... [more ▼]

Rupture of abdominal aortic aneurysms (AAAs) leads to a significant morbidity and mortality in aging populations, and its prediction would be most beneficial to public health. Spots of positive uptake of 18F-FDG detected by PET are found in 12% of AAA patients (PET+), who are most often symptomatic and at high rupture risk. Comparing the 18F-FDG-positive site with a negative site from the same aneurysm and with samples collected from AAA patients with no 18F-FDG uptake should allow the discrimination of biologic alterations that would help in identifying markers predictive of rupture. METHODS: Biopsies of the AAA wall were obtained from patients with no 18F-FDG uptake (PET0, n = 10) and from PET+ patients (n = 8), both at the site of positive uptake and at a distant negative site of the aneurysmal wall. Samples were analyzed by immunohistochemistry, quantitative real-time polymerase chain reaction, and zymography. RESULTS: The sites of the aneurysmal wall with a positive 18F-FDG uptake were characterized by a strikingly increased number of adventitial inflammatory cells, highly proliferative, and by a drastic reduction of smooth muscle cells (SMCs) in the media as compared with their negative counterpart and with the PET0 wall. The expression of a series of genes involved in the maintenance and remodeling of the wall was significantly modified in the negative sites of PET+, compared with the PET0 wall, suggesting a systemic alteration of the aneurysmal wall. Furthermore, a striking increase of several matrix metalloproteinases (MMPs), notably the MMP1 and MMP13 collagenases, was observed in the positive sites, mainly in the adventitia. Moreover, PET+ patients were characterized by a higher circulating C-reactive protein. CONCLUSION: Positive 18F-FDG uptake in the aneurysmal wall is associated with an active inflammatory process characterized by a dense infiltrate of proliferating leukocytes in the adventitia and an increased circulating C-reactive protein. Moreover, a loss of SMC in the media and alterations of the expression of genes involved in the remodeling of adventitia and collagen degradation potentially participate in the weakening of the aneurysmal wall preceding rupture. [less ▲]

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See detailEccentric training improves tendon biomechanical properties: a rat model
Kaux, Jean-François ULg; Drion, Pierre ULg; Libertiaux, Vincent et al

in Journal of Orthopaedic Research (2013), 31(1), 119-124

Introduction: The treatment of choice for tendinopathies is eccentric reeducation. Although the clinical results appear favourable, the biomechanical changes to the tissue are not yet clear. Even if the ... [more ▼]

Introduction: The treatment of choice for tendinopathies is eccentric reeducation. Although the clinical results appear favourable, the biomechanical changes to the tissue are not yet clear. Even if the mechanotransduction theory is commonly accepted, the physiology of tendons is not clearly understood. We aimed to better define the biomechanical and histological changes that affect healthy tendon after eccentric and concentric training. Materiel and Methods: This study compared the effects of 2 methods of training (eccentric (E) training and concentric (C) training) with untrained (U) rats. The animals were trained over a period of 5 weeks. The tricipital, patellar and Achilles tendons were removed, measured and a tensile test until failure was performed. A histological analysis (hematoxylin and eosin and Masson's trichrome stains) was also realized. Results: There was a significant increase in the rupture force of the patellar and tricipital tendons between the U and E groups. The tricipital tendons in the control group presented a significantly smaller cross-sectional area than the E- and C-trained groups, but none was constated between E and C groups. No significant difference was observed for the mechanical stress between the three groups for all three tendons. Histological studies demonstrated the development of a greater number of blood vessels and a larger quantity of collagen in the E group. Discussion and conclusion: The mechanical properties of tendons in rats improve after specific training, especially following eccentric training. Our results partly explained how mechanical loading, especially in eccentric mode, could improve the healing of tendon. [less ▲]

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