References of "Colige, Alain"
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See detailEccentric training improves tendon biomechanical properties: a rat model
Kaux, Jean-François ULiege; Drion, Pierre ULiege; 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 detailEmerging pathogenic mechanisms in human myxomatous mitral valve: lessons from past and novel data.
Hulin, Alexia ULiege; Deroanne, Christophe ULiege; Lambert, Charles ULiege et al

in Cardiovascular pathology : the official journal of the Society for Cardiovascular Pathology (2013), 22(4), 245-50

INTRODUCTION: Myxomatous mitral valve is one of the most common heart valves diseases in human and has been well characterized at a functional and morphological level. Diseased valves are thickened as a ... [more ▼]

INTRODUCTION: Myxomatous mitral valve is one of the most common heart valves diseases in human and has been well characterized at a functional and morphological level. Diseased valves are thickened as a result of extracellular matrix remodeling and proteoglycans accumulation accompanied by the disruption of the stratified structures of the leaflets. METHODS: Global transcriptomic analysis was used as a start-up to investigate potential pathogenic mechanisms involved in the development of the human idiopathic myxomatous mitral valve, which have been elusive for many years. RESULTS: These prospective analyses have highlighted the potential role of apparently unrelated molecules in myxomatous mitral valve such as members of the transforming growth factor-beta superfamily, aggrecanases of the "a disintegrin and metalloprotease with thrombospondin repeats I" family, and a weakening of the protection against oxidative stress. We have integrated, in this review, recent transcriptomic data from our laboratory [A. Hulin, C.F. Deroanne, C.A. Lambert, B. Dumont, V. Castronovo, J.O. Defraigne, et al. Metallothionein-dependent up-regulation of TGF-beta2 participates in the remodelling of the myxomatous mitral valve. Cardiovasc Res 2012;93:480-489] and from the publication of Sainger et al. [R. Sainger, J.B. Grau, E. Branchetti, P. Poggio, W.F. Seefried, B.C. Field, et al. Human myxomatous mitral valve prolapse: role of bone morphogenetic protein 4 in valvular interstitial cell activation. J Cell Physiol 2012;227:2595-2604] with existing literature and information issued from the study of monogenic syndromes and animal models. CONCLUSION: Understanding cellular alterations and molecular mechanisms involved in myxomatous mitral valve should help at identifying relevant targets for future effective pharmacological therapy to prevent or reduce its progression. [less ▲]

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

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

Mature heart valves are complex structures consisting of three highly organized extracellular matrix layers primarily composed of collagens, proteoglycans and elastin. Collectively, these diverse matrix ... [more ▼]

Mature heart valves are complex structures consisting of three highly organized extracellular matrix layers primarily composed of collagens, proteoglycans and elastin. Collectively, these diverse matrix components provide all the necessary biomechanical properties for valve function throughout life. In contrast to healthy valves, myxomatous valve disease is the most common cause of mitral valve prolapse in the human population and is characterized by an abnormal abundance of proteoglycans within the valve tri-laminar structure. Despite the clinical significance, the etiology of this phenotype is not known. Scleraxis (Scx) is a basic-helix-loop-helix transcription factor that we previously showed to be required for establishing heart valve structure during remodeling stages of valvulogenesis. In this study, we report that remodeling heart valves from Scx null mice express decreased levels of proteoglycans, particularly chondroitin sulfate proteoglycans (CSPGs), while overexpression in embryonic avian valve precursor cells and adult porcine valve interstitial cells increases CSPGs. Using these systems we further identify that Scx is positively regulated by canonical Tgfbeta2 signaling during this process and this is attenuated by MAPK activity. Finally, we show that Scx is increased in myxomatous valves from human patients and mouse models, and overexpression in human mitral valve interstitial cells modestly increases proteoglycan expression consistent with myxomatous mitral valve phenotypes. Together, these studies identify an important role for Scx in regulating proteoglycans in embryonic and mature valve cells and suggest that imbalanced regulation could influence myxomatous pathogenesis. [less ▲]

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See detailIsoform 111 of vascular endothelial growth factor (VEGF111) improves angiogenesis of ovarian tissue xenotransplantation
Labied, Soraya ULiege; Delforge, Yves ULiege; Munaut, Carine ULiege 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 ULiege

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 ULiege; Lambert, Charles ULiege 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 ULiege; Janssen, Lauriane ULiege; 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 ULiege; Drion, Pierre ULiege; Colige, Alain ULiege 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 ULiege

Conference (2012, September)

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See detailInfluence of type of contraction upon tendinous tissue during training: animal model
Kaux, Jean-François ULiege; Drion, Pierre ULiege; Croisier, Jean-Louis ULiege et al

in Meeusen, R; Duchateau, J; Roelands, B (Eds.) et al Book of Abstracts of the 17th annual Congress of the ECSS (2012, July)

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. Materiel and ... [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. Materiel and methods: This study compared the effects of two methods of training (eccentric (E) training and concentric (C) training) with untrained (U) rats. The animals underwent training over a period of five weeks. The tricipital, patellar and Achilles tendons were subsequently removed to perform a traction test to the point of tendon 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. No significant difference was observed for the constraints between the three groups for all three tendons. However, a tendency towards improvement was observed between the trained and the U groups for the patellar tendon. Histological studies demonstrated the development of a greater number of blood vessels and a larger quantity of collagen in the eccentric group. Discussion and conclusion: The mechanical properties of tendons in rats improve after specific training, especially following eccentric training. [less ▲]

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See detailGlobal analysis of gene expression in the skin of mice after a 92 days journey in microgravity.
Neutelings, Thibaut ULiege; Liu, Y.; Cancedda, R. et al

Poster (2012, May 04)

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See detailEffects of platelet-rich plasma on the healing of tendons: animal model
Kaux, Jean-François ULiege; Drion, Pierre ULiege; Colige, Alain ULiege et al

in Biomedica 2012 (2012, April)

Introduction: Platelet-Rich Plasma (PRP) contains lot of growth factors which could enhance the healing process of different tissues. We aimed to determine if a single injection of PRP could improve the ... [more ▼]

Introduction: Platelet-Rich Plasma (PRP) contains lot of growth factors which could enhance the healing process of different tissues. We aimed to determine if a single injection of PRP could improve the cicatrisation of ruptured Achilles tendons of rats. Material and Methods: A 5mm defect was surgically made in the Achilles tendon of 120 rats. A few hours after surgery, 45 rats received a PRP or PBS injection in situ. After 5, 15 and 30 days, 20 rats of both groups were euthanized and 15 collected tendons were immediately submitted to a biomechanical tensile strength test until rupture using a “cryo-jaw” device. After, theses samples were used for transcriptomic analyses. Histological and biochemical analyses were performed on the five remained tendons in each group. Results: Tendons in the PRP group were more resistant to rupture at 15 and 30 days than those in the control group. The transverse area of tendons in the PRP group was significantly higher at day 5 and 15. The constraint was significantly increased in tendons of the PRP group in the late phase of the healing (day 30). Histological and immunohistological analysis showed an increased staining for fibrillar collagen at day 5 confirmed by a biochemical analysis showing an increased collagen concentration in the callus. The expression of tenomodulin, a tenocyte differentiation marker, was significantly higher in the PRP-treated tendons at day 5. No significant difference in terms of mRNA for type III collagen and matrix metalloproteinase 9 was observed at any time between the 2 groups. Conclusion: A single injection of PRP in sectioned Achilles tendon of rats few hours after surgery influences the early phase of tendons healing, resulting in an ultimate stronger mechanical resistance. [less ▲]

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