Publications by authors named "Fadoua Montassar"

4 Publications

  • Page 1 of 1

Lebecetin, a C-type lectin, inhibits choroidal and retinal neovascularization.

FASEB J 2017 03 14;31(3):1107-1119. Epub 2016 Dec 14.

Sorbonne Universités, Université Pierre et Marie Curie, INSERM, Centre National de la Recherche Scientifique, Institut de la Vision, Paris, France;

Angiogenesis is a cause of visual impairment and blindness in the wet form of age-related macular degeneration and in ischemic retinopathies. Current therapies include use of anti-VEGF agents to reduce choroidal neovascularization (CNV) and edema. These treatments are effective in most cases, but spontaneous or acquired resistance to anti-VEGF and possible adverse effects of long-term VEGF inhibition in the retina and choroid highlight a need for additional alternative therapies. Integrins αvβ3 and αvβ5, which regulate endothelial cell proliferation and stabilization, have been implicated in ocular angiogenesis. Lebecetin (LCT) is a 30-kDa heterodimeric C-type lectin that is isolated from venom and interacts with α5β1- and αv-containing integrins. We previously showed that LCT inhibits human brain microvascular endothelial cell adhesion, migration, proliferation, and tubulogenesis. To evaluate the inhibitory effect of LCT on ocular angiogenesis, we cultured aortic and choroidal explants in the presence of LCT and analyzed the effect of LCT on CNV in the mouse CNV model and on retinal neovascularization in the oxygen-induced retinopathy model. Our data demonstrate that a single injection of LCT efficiently reduced CNV and retinal neovascularization in these models.-Montassar, F., Darche, M., Blaizot, A., Augustin, S., Conart, J.-B., Millet, A., Elayeb, M., Sahel, J.-A., Réaux-Le Goazigo, A., Sennlaub, F., Marrakchi, N., Messadi, E., Guillonneau, X. Lebecetin, a C-type lectin, inhibits choroidal and retinal neovascularization.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1096/fj.201600351RDOI Listing
March 2017

CC5 and CC8, two homologous disintegrins from Cerastes cerastes venom, inhibit in vitro and ex vivo angiogenesis.

Int J Biol Macromol 2016 May 4;86:670-80. Epub 2016 Feb 4.

Laboratoire des Venins et Biomolécules Thérapeutiques LR11IPT08, Institut Pasteur de Tunis, 13, Place Pasteur, 1002 Tunis, Tunisia; Université de Tunis el Manar, 1068 Tunis, Tunisia; Faculté de Médecine de Tunis, Tunis, Tunisia.

Angiogenesis constitutes a fundamental step in tumor progression. Thus, targeting tumour angiogenesis has been identified to be promising in cancer treatment. In this work, CC5 and CC8, two highly homologous disintegrins isolated from the venom Cerastes cerastes viper from the south of Tunisia, were assessed for their anti-angiogenic effect by testing their ability to interfere with viability, adhesion, migration and angiogenesis of Human Microvascular Endothelial Cells, HMEC-1 and HBMEC. We found that CC5 and CC8 displayed pro-apoptotic potential in HMEC-1 cells. Anoïkis like induced by these two disintegrins was evidenced by cell detachment, down regulation of FAK/AKT/PI3K axis and caspase activation. In addition, both CC5 and CC8 exhibited in vitro anti-adhesive, anti-migratory and anti-proliferative effects on endothelial cells HBMEC. These effects appeared to require RGD and/or WGD loops disintegrin. CC5 and CC8 also inhibited tube-formation on matrigel and displayed potent anti-angiogenic activities as assessed ex vivo, using both the embryo chick chorioallantoic membrane model (CAM) and rat aortic ring assay. Altogether our results demonstrate that CC5 and CC8, are potent inhibitors of angiogenesis, by disrupting αvβ3 and α5β1 binding. The use of CC5 and/or CC8 could provide a beneficial tool to inhibit abnormal angiogenesis and to induce cancer regression.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijbiomac.2016.02.008DOI Listing
May 2016

Upregulation of P2RX7 in Cx3cr1-Deficient Mononuclear Phagocytes Leads to Increased Interleukin-1β Secretion and Photoreceptor Neurodegeneration.

J Neurosci 2015 May;35(18):6987-96

INSERM, U 968, Paris F-75012, France, Sorbonne Universités, UPMC Univ Paris 06, UMR S 968, Institut de la Vision, Paris, F-75012, France, CNRS, UMR 7210, Paris, F-75012, France,

Photoreceptor degeneration in age-related macular degeneration (AMD) is associated with an infiltration and chronic accumulation of mononuclear phagocytes (MPs). We have previously shown that Cx3cr1-deficient mice develop age- and stress- related subretinal accumulation of MPs, which is associated with photoreceptor degeneration. Cx3cr1-deficient MPs have been shown to increase neuronal apoptosis through IL-1β in neuroinflammation of the brain. The reason for increased IL-1β secretion from Cx3cr1-deficient MPs, and whether IL-1β is responsible for increased photoreceptor apoptosis in Cx3cr1-deficient mice, has not been elucidated. Here we show that Cx3cr1-deficient MPs express increased surface P2X7 receptor (P2RX7), which stimulates IL-1β maturation and secretion. P2RX7 and IL-1β inhibition efficiently blunted Cx3cr1-MP-dependent photoreceptor apoptosis in a monocyte/retina coculture system and in light-induced subretinal inflammation of Cx3cr1-deficient mice in vivo. Our results provide an explanation for increased CX3CR1-dependent IL-1β secretion and suggest that IL-1β or P2RX7 inhibition can help inhibit the inflammation-associated photoreceptor cell loss in late AMD, including geographic atrophy, for which no efficient treatment currently exists.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1523/JNEUROSCI.3955-14.2015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6605270PMC
May 2015

Alteration of in vitro and acute in vivo toxicity of textile dyeing wastewater after chemical and biological remediation.

Environ Sci Pollut Res Int 2011 Aug 21;19(7):2634-43. Epub 2012 Feb 21.

Equipe de Recherche en Physico-chimie et Biotechnologie (E.R.P.C.B-EA3914), IUT-UFR Sciences, Université de Caen-Basse, Normandie, France.

Introduction: Textile industry is one of the most common and essential sectors in Tunisia. However, the treatment of textile effluents becomes a university because of their toxic impacts on waters, soils, flora, and fauna.

Materials And Methods: The aim of this work was to evaluate the ability of Pseudomonas putida mt-2 to decolorize a textile wastewater and to compare the biologic decolorization process to the chemical one currently used by the textile industry.

Results: P. putida exhibited a high decolorizing capacity of the studied effluent, compared to the coagulation-flocculation method with decolorization percentage of 86% and 34.5%, respectively. Genotoxicity of the studied effluent, before and after decolorization by P. putida mt-2, was evaluated in vitro, using the SOS chromotest, and in vivo, in mouse bone marrow, by assessing the percentage of cells bearing different chromosome aberrations compared to not treated mice. In addition, textile effluent statistically significant influenced acetylcholinesterase and butyrylcholinesterase activities and lipid peroxidation (p < 0.01) when compared to not-treated mice. Coagulation-flocculation treatment process used by industry was revealed to be ineffective. Indeed toxicities persisted after treatment and the effluent did not show any statistically significant decrease in toxicities compared to non-treated effluent. Our results indicate that P. putida is a promising and improved alternative to treating industrial scale effluent compared to current chemical decolorization procedures used by the Tunisian textile industry.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11356-012-0802-7DOI Listing
August 2011
-->