title: Protease nexin-1 regulates retinal vascular development.
abstract: We recently identified protease nexin-1 (PN-1) or serpinE2, as a possibly underestimated player in maintaining angiogenic balance. Here, we used the well-characterized postnatal vascular development of newborn mouse retina to further investigate the role and the mechanism of action of PN-1 in physiological angiogenesis. The development of retinal vasculature was analysed by endothelial cell staining with isolectin B4. PN-1-deficient (PN-1(-/-)) retina displayed increased vascularization in the postnatal period, with elevated capillary thickness and density, compared to their wild-type littermate (WT). Moreover, PN-1(-/-) retina presented more veins/arteries than WT retina. The kinetics of retinal vasculature development, retinal VEGF expression and overall retinal structure were similar in WT and PN-1(-/-) mice, but we observed a hyperproliferation of vascular cells in PN-1(-/-) retina. Expression of PN-1 was analysed by immunoblotting and X-Gal staining of retinas from mice expressing beta-galactosidase under a PN-1 promoter. PN-1 was highly expressed in the first week following birth and then progressively decreased to a low level in adult retina where it localized on the retinal arteries. PCR arrays performed on mouse retinal RNA identified two angiogenesis-related factors, midkine and Smad5, that were overexpressed in PN-1(-/-) newborn mice and this was confirmed by RT-PCR. Both the higher vascularization and the overexpression of midkine and Smad5 mRNA were also observed in gastrocnemius muscle of PN-1(-/-) mice, suggesting that PN-1 interferes with these pathways. Together, our results demonstrate that PN-1 strongly limits physiological angiogenesis and suggest that modulation of PN-1 expression could represent a new way to regulate angiogenesis.
authors.affiliation: LVTS, INSERM, U1148, Paris, France.|Univ Paris Diderot, Sorbonne Paris Cité, Paris, France.
authors.forename: Sonia
authors.initials: S
authors.lastname: Selbonne
authors.affiliation: LVTS, INSERM, U1148, Paris, France.|Univ Paris Diderot, Sorbonne Paris Cité, Paris, France.
authors.forename: Deborah
authors.initials: D
authors.lastname: Francois
authors.affiliation: UMR_S 968, Institut de la Vision, Paris, France.|Univ Paris 06, UPMC, Paris, France.|Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, INSERM-DHOS CIC 503, 75012, Paris, France.|Université François-Rabelais de Tours, CNRS, GICC UMR 7292, Tours, France.
authors.forename: William
authors.initials: W
authors.lastname: Raoul
authors.affiliation: LVTS, INSERM, U1148, Paris, France.|Univ Paris Diderot, Sorbonne Paris Cité, Paris, France.
authors.forename: Yacine
authors.initials: Y
authors.lastname: Boulaftali
authors.affiliation: UMR_S 968, Institut de la Vision, Paris, France.|Univ Paris 06, UPMC, Paris, France.|Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, INSERM-DHOS CIC 503, 75012, Paris, France.
authors.forename: Florian
authors.initials: F
authors.lastname: Sennlaub
authors.affiliation: LVTS, INSERM, U1148, Paris, France.|Univ Paris Diderot, Sorbonne Paris Cité, Paris, France.
authors.forename: Martine
authors.initials: M
authors.lastname: Jandrot-Perrus
authors.affiliation: LVTS, INSERM, U1148, Paris, France.|Univ Paris Diderot, Sorbonne Paris Cité, Paris, France.
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Bouton
authors.affiliation: LVTS, INSERM, U1148, Paris, France. veronique.arocas@inserm.fr.|Univ Paris Diderot, Sorbonne Paris Cité, Paris, France. veronique.arocas@inserm.fr.
authors.forename: Véronique
authors.initials: V
authors.lastname: Arocas
mesh_terms: D000818:Animals; D005260:Female; D008297:Male; D008810:Mice, Inbred C57BL; D018919:Neovascularization, Physiologic / Q000235:genetics*; D012160:Retina / Q000033:anatomy & histology / Q000254:growth & development / Q000378:metabolism*; D012171:Retinal Vessels / Q000033:anatomy & histology / Q000254:growth & development / Q000378:metabolism; D058258:Serpin E2 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D051902:Smad5 Protein / Q000378:metabolism
chemical_list: D058258:Serpin E2; C511869:Serpine2 protein, mouse; D051902:Smad5 Protein; C497798:Smad5 protein, mouse
keywords: Angiogenesis; PN-1; Retina; Serpin; SerpinE2