Papers by jean-luc wautier
Diabetes, Jul 1, 1996
Exposure of proteins to reducing sugars results in nonenzymatic glycation with the ultimate forma... more Exposure of proteins to reducing sugars results in nonenzymatic glycation with the ultimate formation of advanced glycation end products (AGEs). One means through which AGEs modulate cellular functions is through binding to specific cell surface acceptor molecules. The receptor for AGEs (RAGE) is such a receptor and is a newly identified member of the immunoglobulin superfamily expressed on endothelial cells (ECs), mononuclear phagocytes (MPs), and vascular smooth muscle cells (SMCs) in both vivo and in vitro. Binding of AGEs to RAGE results in induction of cellular oxidant stress, as exemplified by the generation of thiobarbituric acid-reactive substances, expression of heme oxygenase type I, and activation of the transcription factor NF-kB, with consequences for a range of cellular functions. AGEs on the surface of diabetic red cells enhance binding to endothelial RAGE and result in enhanced oxidant stress in the vessel wall. By using reagents to selectively block access to RAGE, the role of this receptor in AGE-mediated perturbation of cellular properties can be dissected in detail. Diabetes 45 (Suppl. 3):S77-S80, 1996
Revue de Médecine Interne, Dec 1, 2007
Propos.-Les dépôts de produits de glycation avancée (ou AGE [advanced glycation end-products]) au... more Propos.-Les dépôts de produits de glycation avancée (ou AGE [advanced glycation end-products]) augmentent dans de nombreux tissus et organes au cours du vieillissement. Les AGE sont impliqués dans la polyarthrite rhumatoïde et la maladie d'Alzheimer. Les AGE participent à la survenue de la dysfonction endothéliale et aux altérations des fonctions cellulaires et tissulaires au cours du diabète (glycotoxines) et de l'insuffisance rénale (toxines urémiques). La fixation d'AGE à des récepteurs provoque une réponse cellulaire pro-inflammatoire, procoagulante et profibrosante néfaste au maintien des fonctions cellulaires. Actualités et points forts.-Les AGE sont les produits finaux de plusieurs voies métaboliques dont la plus connue est la réaction de Maillard (glycation). La glycoxydation est de description plus récente. Alors qu'il n'existe pas de classification bien établie des AGE, les mécanismes physiopathologiques sont mieux connus notamment, en ce qui concerne les conséquences de la fixation des AGE à leur récepteur spécifique RAGE (recepteur aux AGE) endothélial. Les AGE peuvent également exercer leurs effets délétères par glycation in situ ou dépôts de protéines glyquées. Perspectives et projets.-De nombreuses études réalisées in vitro ou chez l'animal montrent que les effets des AGE peuvent être prévenus par des inhibiteurs de glycation, des molécules cassant la liaison sucre-protéines (AGE breakers) ou par le blocage de l'interaction AGE-RAGE. De nouveaux candidats à l'étude pourraient être prometteurs chez l'homme afin de prévenir ou traiter les effets délétères de ces toxines du vieillissement.
Nephrologie & Therapeutique, 2006
Clinical Hemorheology and Microcirculation, 1994
PubMed, Sep 1, 1997
The potential role of tumour necrosis factors (TNFs) in autoimmunity and insulin-dependent diabet... more The potential role of tumour necrosis factors (TNFs) in autoimmunity and insulin-dependent diabetes mellitus (IDDM) led us to determine in vitro TNF-alpha and lymphotoxin-alpha (LT-alpha, TNF-beta) production in IDDM patients according to TNF polymorphism. LT-alpha production of peripheral blood mononuclear cells (PBMC) was lower in diabetic subjects (m = 0.30 +/- 0.2 ng.10(-6) cells) than controls (m = 0.68 +/- 0.3 ng.10(-6) cells, p < 0.05), and early age-at-onset was correlated with low LT-alpha production (rs = 0.8, p = 0.0006). TNF-alpha production was the same in patients and controls, but patients with HbA1c > or = 8% had a higher TNF-alpha production (m = 3.05 +/- 1.2 ng.10(-6) cells) than those with HbA1c < 8% (m = 1.31 +/- 0.33 ng.10(-6) cells, p < 0.05). A study of the microsatellite TNFa region close to the LTA gene showed that the presence of the TNFa1 allele in HLA-(DR3) subjects was associated with increased risk of IDDM. TNFa1-positive subjects (both patients and controls) also had lower LT-alpha production than other subjects. These results indicate that low LT-alpha production is an additional risk factor for IDDM and that poor glycaemic control in patients is associated with enhanced PBMC TNF-alpha production which causes an imbalance between TNF-alpha and LT-alpha production in IDDM patient.
PubMed, 2006
Advanced glycation end-products (AGEs) result from a reaction between carbohydrates and the free ... more Advanced glycation end-products (AGEs) result from a reaction between carbohydrates and the free amino groups of proteins, lipids, and DNA. Non enzymatic glycation, glycoxidation with glucose auto-oxidation and the polyol pathway are involved in glycated protein formation. AGEs also named glycotoxins are found in excess in pathological situations such as diabetes mellitus, renal failure, and aging or after absorption of food containing glycated products. Three major pathophysiological mechanisms are described to explain AGE toxicity, first AGEs can accumulate in the vessel wall and in collagen of different tissues; second in situ glycation is possible; third, AGEs bind to cell receptors inducing deleterious consequences. AGE receptor RAGE is a multiligand member of the immunoglobulin superfamily of cell surface molecules. AGE-receptor interaction can alter, macrophage, endothelial cell, mesangial and mesothelial cell functions and can induce inflammation. Oxidant stress, vascular hyperpermeability, vascular cell adhesion molecule-1 (VCAM-1) overexpression and monocytes chemotactic Protein-1 (MCP-1) production have been observed after cell activation by AGEs. AGEs appear to be involved in the genesis of diabetic macro but also microangiopathy such as retinopathy and glomerulosclerosis. New drugs are tested to prevent or break the AGE-protein cross-linkage, or to control the AGE-receptor interaction and their consequences. Dietary treatment, strict glycemic control and preservation of renal function remain the best approach for preventing AGE formation and limiting their deleterious effects.
Cell Biochemistry and Function, 2001
We used a¯ow system to observe the stepwise adhesion and migration of neutrophils on cultured hum... more We used a¯ow system to observe the stepwise adhesion and migration of neutrophils on cultured human umbilical vein endothelial cells (HUVEC) stimulated with tumour necrosis factor-a (TNF) for 4 h, and to evaluate the effects of pentoxifylline (PTX) at each step. When HUVEC had been stimulated with 100 U ml À 1 TNF, treatment of neutrophils with PTX did not reduce the number captured from¯ow but did cause nearly all adherent cells (>90%) to roll, whereas most untreated cells became immobilized and $ 30% transmigrated within minutes. On washout of the PTX, many rolling cells halted and started to migrate. Treatment of the HUVEC with PTX at the same time as 100 U ml À 1 TNF did not affect the number of neutrophils adhering, but there was a signi®cant increase in the percentage of cells rolling even though PTX was no longer present. Thus PTX reduced presentation of activating agents by HUVEC, as well as inhibiting the response by neutrophils to surface-presented activating agent(s). If HUVEC were stimulated with 10 U ml À 1 TNF with PTX, the adhesion of¯owing neutrophils was greatly inhibited compared to TNF alone. Surface ELISA indicated that PTX reduced TNF-induced upregulation of E-selectin. This reduction was only suf®cient to reduce capture of neutrophils at the low dose of TNF. Thus, by using a¯ow-based model, we have been able to separate the effects of a multipotent agent such as pentoxifylline, which acts on leucocytes and endothelial cells, at each stage of migration.
Circulation Research, Mar 19, 1999
Receptor for advanced glycation end products (RAGE) is a member of the immunoglobulin superfamily... more Receptor for advanced glycation end products (RAGE) is a member of the immunoglobulin superfamily of cell surface molecules and engages diverse ligands relevant to distinct pathological processes. One class of RAGE ligands includes glycoxidation products, termed advanced glycation end products, which occur in diabetes, at sites of oxidant stress in tissues, and in renal failure and amyloidoses. RAGE also functions as a signal transduction receptor for amyloid  peptide, known to accumulate in Alzheimer disease in both affected brain parenchyma and cerebral vasculature. Interaction of RAGE with these ligands enhances receptor expression and initiates a positive feedback loop whereby receptor occupancy triggers increased RAGE expression, thereby perpetuating another wave of cellular activation. Sustained expression of RAGE by critical target cells, including endothelium, smooth muscle cells, mononuclear phagocytes, and neurons, in proximity to these ligands, sets the stage for chronic cellular activation and tissue damage. In a model of accelerated atherosclerosis associated with diabetes in genetically manipulated mice, blockade of cell surface RAGE by infusion of a soluble, truncated form of the receptor completely suppressed enhanced formation of vascular lesions. Amelioration of atherosclerosis in these diabetic/atherosclerotic animals by soluble RAGE occurred in the absence of changes in plasma lipids or glycemia, emphasizing the contribution of a lipid-and glycemia-independent mechanism(s) to atherogenesis, which we postulate to be interaction of RAGE with its ligands. Future studies using mice in which RAGE expression has been genetically manipulated and with selective low molecular weight RAGE inhibitors will be required to definitively assign a critical role for RAGE activation in diabetic vasculopathy. However, sustained receptor expression in a microenvironment with a plethora of ligand makes possible prolonged receptor stimulation, suggesting that interaction of cellular RAGE with its ligands could be a factor contributing to a range of important chronic disorders. (Circ Res. 1999;84:489-497.
Sang Thrombose Vaisseaux, Jan 13, 1998
La glycation des proteines aboutit a la formation de produits de glycation avancee (AGE) que l’on... more La glycation des proteines aboutit a la formation de produits de glycation avancee (AGE) que l’on observe dans le diabete, l’insuffisance renale et le vieillissement. Les AGE sont presents sur les proteines plasmatiques, sur les proteines des parois vasculaires mais aussi a la surface des erythrocytes. Des structures cellulaires capables de lier les AGE sont presentes sur les monocytes-macrophages, lymphocytes, cellules endotheliales, cellules musculaires lisses. Le recepteur des AGE, le mieux caracterise, a ete appele RAGE. Il s’agit d’une molecule d’environ 50 KD qui appartient a la super famille des immunoglobulines. La liaison des AGE aux RAGE endotheliaux induit la formation d’un stress oxydatif et d’une serie de modifications fonctionnelles. La production de formes reactives de l’oxygene s’accompagne d’une activation de NFKB et de la transcription des genes de l’interleukine 6 et du facteur tissulaire. La liaison AGE-RAGE provoque une augmentation de la permeabilite vasculaire qui peut etre prevenue par le blocage du RAGE. L’ensemble des perturbations consecutives a la liaison AGE-RAGE peut jouer un role dans le dysfonctionnement vasculaire observe dans le diabete.
Bio tribune magazine, Mar 1, 2002
Résumé Depuis déjà quelques temps une réflexion est menée pour fixer les bonnes pratiques de lab... more Résumé Depuis déjà quelques temps une réflexion est menée pour fixer les bonnes pratiques de laboratoire en immuno-hématologie érythrocytaire et devrait se finaliser sous la forme d’un arrêté du ministre délégué à la santé.
PubMed, 2004
Erythrocytes in normal conditions have weak interactions with other blood cells and endothelial c... more Erythrocytes in normal conditions have weak interactions with other blood cells and endothelial cells while in pathological circumstances they can adhere to endothelium and aggregate or agglutinate to blood cells. Erythrocyte adhesion was found to be abnormal in sickle cell anemia and diabetes mellitus and correlated to the vascular complications. Further studies demonstrated that VLA-4 adhesion molecule (alpha4beta1) present on erythrocytes bound to vascular cell adhesion molecule (VCAM-1) of the endothelium. In addition, the blood group Lutheran molecule (LU) overexpressed on sickle erythrocytes bind to laminin present on cells or in the intercellular space. In diabetes mellitus the formation of advanced glycation end products (AGE) by reaction between carbohydrates and free aminogroups of lysine is responsible for red blood cell membrane glycation. AGEs present on RBCs bind to the receptor for AGE (RAGE) on endothelium, activating endothelial cells. A molecule related to blood group Rhesus was demonstrated to belong to the intercellular adhesion molecule (ICAM) family. ICAM-4 binds to integrins present on leukocytes (CD11-CD18) and on platelets (alpha2beta4) offering a surface, which can be involved in thrombosis. The identification of erythrocytes adhesion molecules open a new way to understand thrombotic processes and vascular dysfunction.
Transfusion, Oct 1, 2000
BACKGROUND: Blood filtration is a technique widely used to reduce the levels of WBCs in blood com... more BACKGROUND: Blood filtration is a technique widely used to reduce the levels of WBCs in blood components. Several studies have been conducted to define the factors that are involved in WBC reduction, but the various mechanisms are not clearly delineated. This study explored the role of WBC adhesion molecules in WBC reduction during filtration.STUDY DESIGN AND METHODS: A minifilter has been developed that has properties similar to those of the standard filter (Sepacell, Asahi Medical) but that allows a smaller volume of blood to be used (15 mL). WBC reduction was achieved to a similar extent in the standard filter and the minifilter (4.15 log and 4.18 log, respectively). Samples of human promyelocytic cell line (HL60) were filtered before and after differentiation induced by vitamin D3 (D3‐HL60). Flow cytometry was used to characterize the D3‐HL60 filtrates and to count the WBCs after filtration.RESULTS: HL60 was retained in the filter to the same extent as all other WBCs. A higher level of integrin receptors (CD11b/CD18; CD11c/CD18) was expressed by D3‐HL60 than by HL60. When the blood was incubated with anti‐CD11b, anti‐CD11c, or anti‐CD18, fewer D3‐HL60 cells were trapped by the filter, while only anti‐CD11b alters HL60 retention in the filter.CONCLUSION: The receptors CD11b/CD18 and CD11c/CD18 appear to bind to the filter fibers and to be one of the mechanisms responsible for WBC retention.
Diabetes & Metabolism, 1999
L'incidence elevee des complications vasculaires dans le diabete sucre a incite a explorer le... more L'incidence elevee des complications vasculaires dans le diabete sucre a incite a explorer les possibles mecanismes physiopathologiques. Diverses anomalies metaboliques et endocriniennes ont ete soupconnees d'etre responsables des atteintes vasculaires. L'hyperglycemie a des consequences multiples et en particulier la formation de produits de glycation avancee (AGE) et de nombreux travaux recents mettent l'accent sur le role central des AGE dans la genese de l'atteinte vasculaire. Les AGE resultent de la liaison d'aldoses aux groupements amines libres des proteines qui apres des rearrangements moleculaires complexes aboutissent a la formation d'une classe de molecules ayant une couleur brunâtre et une fluorescence specifique. Les AGE se fixent a des recepteurs dont le mieux caracterise est le RAGE. La liaison des AGE au RAGE stimule l'expression du RAGE et l'activation cellulaire. Dans un modele d'atherosclerose acceleree chez des souris diabetiques manipulees genetiquement le blocage de l'interaction AGE-RAGE par du RAGE soluble supprime l'acceleration des lesions vasculaires. L'amelioration des lesions chez ces animaux atherosclereux/diabetiques en l'absence de correction des lipides ou de la glycemie, montre qu'il existe un mecanisme independant des lipides et de la glycemie.
PubMed, Sep 1, 1995
Uptake of [3H]colchicine (2.5 ng/ml) by human lymphocytes in culture was slow in the length of ti... more Uptake of [3H]colchicine (2.5 ng/ml) by human lymphocytes in culture was slow in the length of time to reach steady state (> 48 hr) and was limited in the maximal intracellular colchicine amount (1-2% of total extracellular colchicine). Efflux of intracellular colchicine was investigated 40 hr after colchicine cell exposure by using either washing of the extracellular medium or adding different colchicine-specific Fab fragments:colchicine dose molar ratios of 0.5, 1 and 5. Except for the 0.5 dose molar ratio, the kinetics of [3H]colchicine efflux from lymphocytes induced by extracellular specific Fab fragments were similar to those obtained by washing and were characterized by a first-order decline with half-lives ranging from 15.5 to 16.4 hr. These half-lives were in the same range as those characterizing the dissociation of colchicine from the intracellular tubulin receptor. Our data demonstrate that a tightly bound intracellular toxin may be extracted by antibody with high affinity for the toxin present in the extracellular space at a rate depending on the rate of dissociation of the toxin from its receptor.
Clinical Hemorheology and Microcirculation, 1992
The blood monocytes adhere to endothelial cells unstimulated and after stimulation by interleukin... more The blood monocytes adhere to endothelial cells unstimulated and after stimulation by interleukin-l, tumor necrosis factor or other mediators. This process is mediated through specific molecules on both endothelial cells and monocytes. Using specific monoclonal antibodies and molecular cloning several families of molecules involved in leukocyte-endothelial cell interaction have been defined. Leukocyte adhesion molecules include the three ~2 integrins (CD lUCD 18 molecules), VLA-4 and the L-Selectin. E-Selectin (ELAM-l), P-Selectin (GMP-140) and receptors of the immunoglobulin superfamily (ICAM-l, ICAM-2 and VCAM-l) are expressed on endothelial cells in basal conditions and after activation by cytokines. It has been shown that these adhesive molecules are involved in blood monocyte adhesion to endothelial cells in vitro. The in vivo expression of these adhesive molecules on the vascular endothelium has been described in acute and chronic inflammatory situations such as Kawasaki syndrome and atherosclerosis.
PubMed, Sep 1, 1999
The accelerated formation of advanced glycation end products (AGEs) is implicated in diabetic mic... more The accelerated formation of advanced glycation end products (AGEs) is implicated in diabetic microvascular and macrovascular complications. The binding of AGEs to their cellular surface receptor (RAGE) induces vascular dysfunction and in particular an increase in vascular permeability. We previously demonstrated that rat recombinant RAGE (rR-RAGE) produced in insect cells corrected the hyperpermeability due to RAGE-AGE interaction and that pharmacokinetic properties of rR-RAGE after i.v. administration in rats were compatible with a potential therapeutic use. In the present study, we showed that recombinant human RAGE (rH-RAGE) had a similar efficacy in inhibiting AGE-induced endothelial alteration and in reducing the hyperpermeability observed in streptozotocin-induced diabetic rats. (125)I-rH-RAGE elimination half-life after i.v. administration was similar in diabetic and normal rats (53.7 +/- 7.6 and 45.3 +/- 4.0 h, respectively). The presence of AGEs is responsible for a higher distribution volume in diabetic rats compared with normal rats (15.3 +/- 2.7 and 7.7 +/- 0. 7 l/kg, respectively). Immunoreactive (125)I-rH-RAGE decreased more rapidly than did immunoreactive (125)I-rR-RAGE. The differences between (125)I-rH-RAGE and (125)I-rR-RAGE pharmacokinetics in rat may be related to differences in potential O-glycosylation and protease cleavage sites between the two RAGE molecules.
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Papers by jean-luc wautier