References of "Colige, Alain"
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See detailInterets de la tomographie a eimission de positons dans le suivi et le pronostic des anevrysmes de l'aorte abdominale.
Courtois, Audrey ULg; Nusgens-Richelle, Betty ULg; Hustinx, Roland ULg et al

in Revue medicale de Liege (2014), 69 Spec No

Rupture of abdominal aortic aneurysm (AAA) remains a major cause of death in the elderly. Its prediction is a serious challenge for public health. Despite its regular use to identify patients requiring ... [more ▼]

Rupture of abdominal aortic aneurysm (AAA) remains a major cause of death in the elderly. Its prediction is a serious challenge for public health. Despite its regular use to identify patients requiring surgical treatment, the diameter of AAA is not a sufficiently precise and reliable parameter for discriminating aneurysms at high risk of rupture. A better targeting of high risk patients needs understanding in deep the processes and mechanisms directing wall rupture. Inflammation is a significant element in the progression ofAAA and can be visualized using medical imaging techniques such as positron emission tomography (PET) using a glucose derivative (FDG) as radiotracer. Studies conducted in our department have established a relationship between PET positivity and the presence of symptoms such as accelerated growth of the aneurysm or pain, signs generally considered as predictive of rupture. Moreover, activation of leukocytes coupled to cellular and molecular alterations of the aneurysmal wall in the sites of FDG uptake may lead to its instability and incompetence to resist blood pressure and rupture. PET therefore represents a new original exploration method to characterize the severity of AAA progression allowing to assess the need for a surgical treatment much better than does the AAA diameter. [less ▲]

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See detailCell Models Adapted to Real-Time Imaging of the Cytoskeleton Dynamics in Altered Gravity
Willems, Jérôme ULg; Deroanne, Christophe ULg; Colige, Alain ULg et al

in Microgravity Science and Technology (2014), 26(4), 257-270

Spatial and temporal regulation of cell phenotype by mechanical forces is a growing field of research in health sciences since these stimuli influence cellular functions, such as proliferation, migration ... [more ▼]

Spatial and temporal regulation of cell phenotype by mechanical forces is a growing field of research in health sciences since these stimuli influence cellular functions, such as proliferation, migration, differentiation and gene expression. In the context of the Fluolive project selected by the European Space Agency and aiming at evaluating the impact of gravity alterations on the cell phenotype, we have developed new bone-derived cell lines adapted for live-cell imaging of the cytoskeleton. Osteoblastic cells derived from human osteosarcomas were used as experimental models. U2-OS and SaoS-2 cells stably expressing TagGFP2- β-actin and mCherry- α-tubulin were established and single-cell clonal cultures were characterized in terms of recombinant proteins production and localization, fluorescence intensity, cell proliferation and migration rates. Living fluorescently-tagged cell lines allow real-time fluorescence microscopy of the cytoskeleton dynamics without bleaching and without alteration of cell morphology. U2-OS and SaoS-2 TagGFP2- β-actin and mCherry- α-tubulin clones will be used to monitor the effect of mechanical forces in models of altered gravity on Earth and possibly on the ISS. © 2014, Springer Science+Business Media Dordrecht. [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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See detailIsoform 111 of vascular endothelial growth factor (VEGF111) improves angiogenesis of ovarian tissue xenotransplantation
Labied, Soraya ULg; Delforge, Yves ULg; Munaut, Carine ULg et al

in Transplantation (2013), 95(3), 426-433

Background: Cryopreservation of cortex ovarian tissue before anti-cancer therapy is a promising technique for fertility preservation mainly in children and young women. Ischemia in the early stage after ... [more ▼]

Background: Cryopreservation of cortex ovarian tissue before anti-cancer therapy is a promising technique for fertility preservation mainly in children and young women. Ischemia in the early stage after ovarian graft causes massive follicle loss by apoptosis. VEGF111 is a recently described VEGF isoform that does not bind to the extracellular matrix, diffuse extensively and is resistant to proteolysis. These properties confer a significantly higher angiogenic potential to VEGF111 in comparison to the other VEGF isoforms. Methods: We evaluated the morphology of cryopreserved sheep ovarian cortex, grafted in the presence or absence of VEGF111. Ovarian cortex biopsies were embedded in type I collagen with or without VEGF111 addition before transplantation to SCID mice ovaries. Transplants were retrieved 3 days or 3 weeks later. Follicular density, vasculature network, haemoglobin content and cell proliferation were analysed. Results: Addition of VEGF111 increased density of functional capillaries (p=0.01) 3 days after grafting. By double immunostaining of Ki-67 and von Willebrand Factor (vWF) we demonstrated that proliferating endothelial cells were found in 83% of the VEGF111 group when compared to 33% in the control group (p=0.001). This angio-stimulation was associated with a significant enhancement of haemoglobin content (p=0.03). Three weeks after transplantation, the number of primary follicles was significantly higher in VEGF111 grafts (p=0.02). Conclusion: VEGF111 accelerates blood vessels recruitment, functional angiogenesis and improves the viability of ovarian cortex by limiting ischemia and ovarian cortex damage. [less ▲]

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See detailProcollagen N-endopeptidases.
Colige, Alain ULg

in Rawlings, Neil D.; Salvesen, Guy (Eds.) Handbook of proteolytic enzymes. 3rd Edition (2013)

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See detailEmerging pathogenic mechanisms in human myxomatous mitral valve: lessons from past and novel data.
Hulin, Alexia; Deroanne, Christophe ULg; Lambert, Charles ULg et al

in Cardiovascular Pathology (2013), 22

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See detailNew prospects in the roles of the C-terminal domains of VEGF-A and their cooperation for ligand binding, cellular signaling and vessels formation.
Delcombel, Romain ULg; Janssen, Lauriane ULg; Vassy, Roger et al

in Angiogenesis (2013), 16(2), 353-71

VEGF-A is a crucial growth factor for blood vessel homeostasis and pathological angiogenesis. Due to alternative splicing of its pre-mRNA, VEGF-A is produced under several isoforms characterized by the ... [more ▼]

VEGF-A is a crucial growth factor for blood vessel homeostasis and pathological angiogenesis. Due to alternative splicing of its pre-mRNA, VEGF-A is produced under several isoforms characterized by the combination of their C-terminal domains, which determines their respective structure, availability and affinity for co-receptors. As controversies still exist about the specific roles of these exon-encoded domains, we systematically compared the properties of eight natural and artificial variants containing the domains encoded by exons 1-4 and various combinations of the domains encoded by exons 5, 7 and 8a or 8b. All the variants (VEGF(111)a, VEGF(111)b, VEGF(121)a, VEGF(121)b, VEGF(155)a, VEGF(155)b, VEGF(165)a, VEGF(165)b) have a similar affinity for VEGF-R2, as determined by Surface plasmon resonance analyses. They strongly differ however in terms of binding to neuropilin-1 and heparin/heparan sulfate proteoglycans. Data indicate that the 6 amino acids encoded by exon 8a must be present and cooperate with those of exons 5 or 7 for efficient binding, which was confirmed in cell culture models. We further showed that VEGF(165)b has inhibitory effects in vitro, as previously reported, but that the shortest VEGF variant possessing also the 6 amino acids encoded by exon 8b (VEGF(111)b) is remarkably proangiogenic, demonstrating the critical importance of domain interactions for defining the VEGF properties. The number, size and localization of newly formed blood vessels in a model of tumour angiogenesis strongly depend also on the C-terminal domain composition, suggesting that association of several VEGF isoforms may be more efficient for treating ischemic diseases than the use of any single variant. [less ▲]

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See detailEffects of platelet-rich plasma (PRP) on the healing of Achilles tendons of rats
Kaux, Jean-François ULg; Drion, Pierre ULg; Colige, Alain ULg et al

in Wound Repair & Regeneration : Official Publication of the Wound Healing Society and the European Tissue Repair Society (2012), 20(5), 748-756

Platelet-Rich Plasma (PRP) contains growth factors involved in the tissular healing process. The aim of the study was to determine if an injection of PRP could improve the healing of sectioned Achilles ... [more ▼]

Platelet-Rich Plasma (PRP) contains growth factors involved in the tissular healing process. The aim of the study was to determine if an injection of PRP could improve the healing of sectioned Achilles tendons of rats. After surgery, rats received an injection of PRP (n=60) or a physiological solution (n=60) in situ. After 5, 15 and 30 days, 20 rats of both groups were euthanized and 15 collected tendons were submitted to a biomechanical test using cryo-jaws before performing transcriptomic analyses. Histological and biochemical analyses were performed on the 5 remaining tendons in each group. Tendons in the PRP group were more resistant to rupture at 15 and 30 days. The mechanical stress was significantly increased in tendons of the PRP group at day 30. Histological analysis showed a precocious deposition of fibrillar collagen at day 5 confirmed by a biochemical measurement. The expression of tenomodulin was significantly higher at day 5. The mRNA level of type III collage, matrix metalloproteinase 2, 3 and 9 was similar in the 2 groups at all time points whereas type I collagen was significantly increased at day 30 in the PRP group. In conclusion, an injection of PRP in sectioned rat Achilles tendon influences the early phase of tendons healing and results in an ultimate stronger mechanical resistance. [less ▲]

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See detailDermatosparaxis : altered processing of type I procollagen by ADAMTS2 and beyond.
Colige, Alain ULg

Conference (2012, September)

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