title: Planar cell polarity genes frizzled4 and frizzled6 exert patterning influence on arterial vessel morphogenesis.
abstract: Quantitative analysis of the vascular network anatomy is critical for the understanding of the vasculature structure and function. In this study, we have combined microcomputed tomography (microCT) and computational analysis to provide quantitative three-dimensional geometrical and topological characterization of the normal kidney vasculature, and to investigate how 2 core genes of the Wnt/planar cell polarity, Frizzled4 and Frizzled6, affect vascular network morphogenesis. Experiments were performed on frizzled4 (Fzd4-/-) and frizzled6 (Fzd6-/-) deleted mice and littermate controls (WT) perfused with a contrast medium after euthanasia and exsanguination. The kidneys were scanned with a high-resolution (16 μm) microCT imaging system, followed by 3D reconstruction of the arterial vasculature. Computational treatment includes decomposition of 3D networks based on Diameter-Defined Strahler Order (DDSO). We have calculated quantitative (i) Global scale parameters, such as the volume of the vasculature and its fractal dimension (ii) Structural parameters depending on the DDSO hierarchical levels such as hierarchical ordering, diameter, length and branching angles of the vessel segments, and (iii) Functional parameters such as estimated resistance to blood flow alongside the vascular tree and average density of terminal arterioles. In normal kidneys, fractal dimension was 2.07±0.11 (n = 7), and was significantly lower in Fzd4-/- (1.71±0.04; n = 4), and Fzd6-/- (1.54±0.09; n = 3) kidneys. The DDSO number was 5 in WT and Fzd4-/-, and only 4 in Fzd6-/-. Scaling characteristics such as diameter and length of vessel segments were altered in mutants, whereas bifurcation angles were not different from WT. Fzd4 and Fzd6 deletion increased vessel resistance, calculated using the Hagen-Poiseuille equation, for each DDSO, and decreased the density and the homogeneity of the distal vessel segments. Our results show that our methodology is suitable for 3D quantitative characterization of vascular networks, and that Fzd4 and Fzd6 genes have a deep patterning effect on arterial vessel morphogenesis that may determine its functional efficiency.
authors.affiliation: Department of Physics, Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia.|Faculty of Education, University of Maribor, Maribor, Slovenia.
authors.forename: Rene
authors.initials: R
authors.lastname: Markovič
authors.affiliation: INSERM, Biology of Cardiovascular Diseases U1034, Pessac, France.|Université de Bordeaux, Biology of Cardiovascular Diseases U1034, Pessac, France.|Service des Maladies Cardiaques et Vasculaires, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Peltan
authors.affiliation: Department of Physics, Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia.|Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia.
authors.forename: Marko
authors.initials: M
authors.lastname: Gosak
authors.affiliation: Faculty of Electrical Engineering and Computer Science, University of Maribor, Maribor, Slovenia.
authors.forename: Denis
authors.initials: D
authors.lastname: Horvat
authors.affiliation: Faculty of Electrical Engineering and Computer Science, University of Maribor, Maribor, Slovenia.
authors.forename: Borut
authors.initials: B
authors.lastname: Žalik
authors.affiliation: INSERM, Biology of Cardiovascular Diseases U1034, Pessac, France.|Service des Maladies Cardiaques et Vasculaires, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Seguy
authors.affiliation: INSERM, Biology of Cardiovascular Diseases U1034, Pessac, France.|Université de Bordeaux, Biology of Cardiovascular Diseases U1034, Pessac, France.|Service des Maladies Cardiaques et Vasculaires, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France.
authors.forename: Remi
authors.initials: R
authors.lastname: Chauvel
authors.affiliation: INRIA, Morpheme team, Sophia Antipolis, France.
authors.forename: Gregoire
authors.initials: G
authors.lastname: Malandain
authors.affiliation: INSERM, Biology of Cardiovascular Diseases U1034, Pessac, France.|Université de Bordeaux, Biology of Cardiovascular Diseases U1034, Pessac, France.|Service des Maladies Cardiaques et Vasculaires, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Couffinhal
authors.affiliation: INSERM, Biology of Cardiovascular Diseases U1034, Pessac, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Duplàa
authors.affiliation: Department of Physics, Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia.|Faculty of Education, University of Maribor, Maribor, Slovenia.|Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia.
authors.forename: Marko
authors.initials: M
authors.lastname: Marhl
authors.affiliation: INSERM, Biology of Cardiovascular Diseases U1034, Pessac, France.|Université de Bordeaux, Biology of Cardiovascular Diseases U1034, Pessac, France.
authors.forename: Etienne
authors.identifier: http://orcid.org/0000-0003-4828-5722
authors.initials: E
authors.lastname: Roux
mesh_terms: D000818:Animals; D001158:Arteries / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000254:growth & development* / Q000502:physiology; D016764:Cell Polarity / Q000235:genetics*; D051157:Frizzled Receptors / Q000235:genetics* / Q000378:metabolism*; D051379:Mice; D009024:Morphogenesis / Q000235:genetics*; D018919:Neovascularization, Physiologic; D055114:X-Ray Microtomography
chemical_list: D051157:Frizzled Receptors; C498581:Fzd4 protein, mouse; C111048:Fzd6 protein, mouse