MMP-19 Deficiency Promotes Tenascin-C Accumulation and Allergen-induced Airway Inflammation.

in American Journal of Respiratory Cell and Molecular Biology (2010), 43(3), 286-95

Matrix metalloproteinases (MMPs) recently appeared as key regulators of inflammation, allowing recruitment and clearance of inflammatory cells and modifying the biological activity of many peptidic ... [more ▼]

Matrix metalloproteinases (MMPs) recently appeared as key regulators of inflammation, allowing recruitment and clearance of inflammatory cells and modifying the biological activity of many peptidic mediators by cleavage. MMP-19 is a newly described MMP and preferentially cleaves matrix proteins such as collagens and tenascin-C. The role of MMP-19 in asthma has not been described to date. The purpose of the present study was to assess MMP-19 expression in a murine asthma model and to address biological effects of MMP-19 deficiency in mice. Allergenexposed wild-type (WT) mice displayed an increased expression of MMP-19 mRNA and an increased number of MMP-19-positive cells in the lungs detected by immunohistochemistry. After allergen challenge of MMP-19 knockout (MMP-19-/-) mice, an exacerbated eosinophilic inflammation was detected in bronchoalveolar lavage fluid and bronchial tissue along with an increased airway responsiveness to methacholine. A shift towards increased Th2-driven inflammation in MMP-19-/- mice was demonstrated by 1) increased numbers of cells expressing the IL-33 receptor T1/ST2 in lung parenchyma, 2) increased IgG1 levels in serum and 3) higher levels of IL-13 and CCL11 in lung extracts. Tenascin-C was found accumulated in peribronchial areas of MMP-19-/- after allergen challenges as assessed by Western blot and immunohistochemistry analysis. We conclude that MMP-19 is a new mediator in asthma, preventing tenascin-C accumulation and directly or indirectly controlling Th2-driven airway eosinophilia and airway hyperreactivity. Our data suggest that MMP-19 might act on Th2 inflammation homeostasis through preventing tenascin protein accumulation. [less ▲]

Diabete et grossesse: impact de l'inertie medicale et de l'observance therapeutique.

in Revue Médicale de Liège (2010), 65(5-6), 399-404

Pregnancy and infant outcomes are related to maternal blood glucose profile. Managing preexisting diabetes and achieving euglycaemia before and during the pregnancy reduce the risk for complications ... [more ▼]

Pregnancy and infant outcomes are related to maternal blood glucose profile. Managing preexisting diabetes and achieving euglycaemia before and during the pregnancy reduce the risk for complications. Screening, diagnosis and treatment of gestational diabetes are important issues from a public health point of view, more particularly because of the progression of this disease due to obesity epidemics among young people. Pregnancy in a diabetic woman is a critical situation where neither clinical inertia nor patient's non-compliance could be accepted. [less ▲]

Conception, synthèse et évaluation biologique de dérivés coumariniques en tant qu’agents anti-cancéreux potentiels

Poster (2009, May)

New asthma biomarkers: lessons from murine models of acute and chronic asthma.

in American Journal of Physiology - Lung Cellular and Molecular Physiology (2009), 296(2), 185-97

Many patients suffering from asthma are not fully controlled by currently available treatments, and some of them display an airway remodeling leading to exaggerated lung function decline. The aim of the ... [more ▼]

Many patients suffering from asthma are not fully controlled by currently available treatments, and some of them display an airway remodeling leading to exaggerated lung function decline. The aim of the present study was to unveil new mediators in asthma to better understand pathophysiology and propose or validate new potential therapeutic targets. A mouse model of asthma mimicking acute or chronic asthma disease was used to select genes undergoing a modulation in both acute and chronic conditions. Mice were exposed to ovalbumin or PBS for 1, 5, and 10 wk [short-, intermediate-, and long-term model (ST, IT, and LT)], and gene expression in the lung was studied using an Affymetrix 430 2.0 genome-wide microarray and further confirmed by RT-PCR and immunohistochemistry for selected targets. We report that 598, 1,406, and 117 genes were upregulated and 490, 153, 321 downregulated at ST, IT, and LT, respectively. Genes related to mucous secretion displayed a progressively amplified expression during the allergen exposure protocol, whereas genes corresponding to growth and differentiation factors, matrix metalloproteinases, and collagens were mainly upregulated at IT. By contrast, genes related to cell division were upregulated at ST and IT and were downregulated at LT. In this study, besides confirming that Arg1, Slc26a4, Ear11, and Mmp12 genes are highly modulated throughout the asthma pathology, we show for the first time that Agr2, Scin, and Cd209e genes are overexpressed throughout the allergen exposure and might therefore be considered as suitable new potential targets for the treatment of asthma. [less ▲]

Role of ADAM and ADAMTS metalloproteinases in airway diseases

in Respiratory Research (2009), 10(1), 127

Lungs are exposed to the outside environment and therefore to toxic and infectious agents or allergens. This may lead to permanent activation of innate immune response elements. A Disintegrin And ... [more ▼]

Lungs are exposed to the outside environment and therefore to toxic and infectious agents or allergens. This may lead to permanent activation of innate immune response elements. A Disintegrin And Metalloproteinases (ADAMs) and ADAMs with Thrombospondin motifs (ADAMTS) are proteinases closely related to Matrix Metalloproteinases (MMPs). These multifaceted molecules bear metalloproteinase and disintegrin domains endowing them with features of both proteinases and adhesion molecules. Proteinases of the ADAM family are associated to various physiological and pathological processes and display a wide spectrum of biological effects encompassing cell fusion, cell adhesion, "shedding process", cleavage of various substrates from the extracellular matrix, growth factors or cytokines... This review will focus on the putative roles of ADAM/ADAMTS proteinases in airway diseases such as asthma and COPD. [less ▲]

VEGF-D deficiency in mice does not affect embryonic or postnatal lymphangiogenesis but reduces lymphatic metastasis.

in Journal of Pathology (The) (2009), 219(3), 356-364

Vascular endothelial growth factor-D (VEGF-D) is one of the two ligands of the VEGFR-3 receptor on lymphatic endothelial cells. Gene-silencing studies in mice and Xenopus tadpoles recently showed that the ... [more ▼]

Vascular endothelial growth factor-D (VEGF-D) is one of the two ligands of the VEGFR-3 receptor on lymphatic endothelial cells. Gene-silencing studies in mice and Xenopus tadpoles recently showed that the role of endogenous VEGF-D in lymphatic development is moderate. By contrast, exogenous VEGF-D is capable of stimulating lymphangiogenesis. Nonetheless, its endogenous role in pathological conditions remains largely unknown. Hence, we reassessed its role in disease, using Vegf-dnull mice. Vegf-dnull mice were generated that, under physiological conditions, displayed normal embryonic and postnatal lymphangiogenesis and lymphatic remodelling, efficient lymphatic functioning and normal health. Vegf-dnull mice also reponded normally in models of skin wound healing and healing of infarcted myocardium, despite enhanced expression of VEGF-D in these models in wild-type mice. In contrast, Vegf-dnull mice displayed reduced peritumoral lymphangiogenesis and lymph node metastasis in an orthotopic pancreatic tumour model. Together, our data indicate that endogenous VEGF-D in mice is dispensible for lymphangiogenesis during development, in postnatal and adult physiology and in several pathological conditions, but significantly contributes to lymphatic metastasis. [less ▲]

Chorionic Gonadotropin Stimulation of Angiogenesis and Pericyte Recruitment

in Journal of Clinical Endocrinology and Metabolism (2009), 94(11), 4567-74

During the periimplantation period, human chorionic gonadotropin (hCG) plays a key role by increasing the uterine blood flow through uterine vessel vasodilatation but also through angiogenesis. Indeed, we ... [more ▼]

During the periimplantation period, human chorionic gonadotropin (hCG) plays a key role by increasing the uterine blood flow through uterine vessel vasodilatation but also through angiogenesis. Indeed, we previously demonstrated that hCG contributes to endothelial cell recruitment and vessel formation. OBJECTIVE: In this study, hCG was proposed as an arteriogenic factor that could promote perivascular cell recruitment and vessel stabilization. DESIGN: The aortic ring assay, a three-dimensional ex vivo angiogenesis system mimicking all the steps of the angiogenesis process was used to study the impact of hCG on pericyte recruitment and vessel maturation. SETTING: The study was conducted at a university hospital laboratory. MAIN OUTCOME MEASURES: Perivascular cell proliferation, migration, and apposition were quantified by computerized image analysis. RESULTS: Physiological concentrations of hCG (10-400 IU/ml) significantly enhanced pericyte sprouting and migration and gave rise to the maturation and coverage of endothelial capillaries. In a three-dimensional coculture model of endothelial and perivascular cells, hCG enhanced vessel tube formation and endothelial/mural cell adhesion. In addition, hCG stimulated the proliferation of human umbilical vein endothelial cells and smooth muscle cells. The specificity of these effects was determined by using an anti-hCG blocking antibody. Signaling pathways implicated on this hCG effect is protein kinase A and phospholipase C/protein kinase C dependent for the proliferative effect but only phospholipase C/protein kinase C for the migrative process. CONCLUSIONS: Our findings highlight a novel paracrine role of this early embryonic signal in vessel maturation by stimulating perivascular cell recruitment, migration, and proliferation. [less ▲]

Mixed origin of neovascularization of human endometrial grafts in immunodeficient mouse models

in Human Reproduction (2009), 24(9), 2217-24

BACKGROUND: In vivo mouse models have been developed to study the physiology of normal and pathologic endometrium. Although angiogenesis is known to play an important role in endometrial physiology and ... [more ▼]

BACKGROUND: In vivo mouse models have been developed to study the physiology of normal and pathologic endometrium. Although angiogenesis is known to play an important role in endometrial physiology and pathology, the origin of neovasculature in xenografts remains controversial. The aim of this study was to assess the origin of the neovasculature of endometrial grafts in different mouse models. METHODS: Human proliferative endometrium (n = 19 women) was grafted s.c. in two immunodeficient mouse strains: nude (n = 8) and severely compromised immunodeficient (SCID; n = 20). Mice were also treated with estradiol, progesterone or levonorgestrel. Fluorescence in-situ hybridization using a centromeric human chromosome X probe, immunohistochemistry (von Willebrand factor and collagen IV) and lectin perfusion were performed to identify the origin of the vessels. RESULTS: More than 90% of vessels within xenografts were of human origin 4 weeks after implantation. Some vessels (9.67 +/- 2.01%) were successively stained by human or mouse specific markers, suggesting the presence of chimeric vessels exhibiting a succession of human and murine portions. No difference in staining was observed between the two strains of mouse or different hormone treatments. Furthermore, erythrocytes were found inside human vessels, confirming their functionality. CONCLUSION: This article shows that human endometrial grafts retain their own vessels, which connect to the murine vasculature coming from the host tissue and become functional. [less ▲]

Coment j'explore...- les pertes de sang d'origine vaginale dans l'enfance

in Revue Médicale de Liège (2009), 64(4), 219-22

Le saignement vaginal prépubertaire est considéré comme une ménarche isolée lorsque, en l’absence de toute anomalie mise en évidence par les examens médicaux (corps étranger, tumeur, infection…), il n’y ... [more ▼]

Le saignement vaginal prépubertaire est considéré comme une ménarche isolée lorsque, en l’absence de toute anomalie mise en évidence par les examens médicaux (corps étranger, tumeur, infection…), il n’y pas de développement d’un autre caractère sexuel secondaire. Si d’autres signes pubertaires (thélarche, pubarche, pic de croissance, …) se développent, le saignement vaginal ne sera plus isolé et nous parlerons dès lors de puberté précoce vraie. C’est donc le suivi de la patiente qui nous permettra de faire le diagnostic différentiel entre ménarche précoce isolée bénigne et puberté précoce vraie engageant le pronostic statural et nécessitant une prise en charge spécifique. L’étiologie de la ménarche isolée reste indéterminée et des études complémentaires sont nécessaires. Plusieurs examens complémentaires doivent être réalisés afin d’exclure des pathologies tumorales, infectieuses, traumatiques ou encore hormonales et ceux-ci doivent être répétés lors du suivi de la patiente. [less ▲]

Débats actuels sur l'immunologie de la prééclampsie. Comptes rendus du sixième colloque international de La Réunion (décembre 2008)

in Gynécologie Obstétrique & Fertilité (2009), 37(6), 570-8

Hypertensive disorders of pregnancy (HDP) represent globally 10% of human births and their major complication, preeclampsia, 3 to 5%. The etiology of these HDP remains still uncertain, however major ... [more ▼]

Hypertensive disorders of pregnancy (HDP) represent globally 10% of human births and their major complication, preeclampsia, 3 to 5%. The etiology of these HDP remains still uncertain, however major advances have been made these last 25 years. The Sixth International Workshop on Reproductive Immunology, Immunological Tolerance and Immunology of Preeclampsia 2008 celebrated its 10th Anniversary in Reunion-island (French overseas Department in the Indian Ocean). Over this decade, these six workshops have contributed extensively to immunological, epidemiological, anthropological and even vascular debates. The defect of trophoblastic invasion encountered in preeclampsia, intra-uterine growth retardation and to some extend also preterm labour has been understood only at the end of the 1970's. On the other hand, clinical and epidemiological findings at the end of the 20th century permitted to apprehend that “preeclampsia disease of primiparae” may in fact well be the disease of first pregnancies at the level of human couples. Among the important advances, immunology of reproduction is certainly the topic where knowledge has literally exploded in the last decade. This paper relates some major steps in comprehension of this disease and focuses on the interest to follow these immunological works and their new concepts. It seems, at the beginning of the 21st century, that we are possibly closer than ever to understand the etiology of this obstetrical enigma. In this quest, the immunology of reproduction will certainly come out as one of the main players. [less ▲]