Christoph Schürmann1,2, Franziska L Dienst1, Katalin Pálfi1, Andrea E Vasconez1,2, James A Oo1,2, ShengPeng Wang3, Giulia K Buchmann1,2, Stefan Offermanns2,3, Bart van de Sluis4, Matthias S Leisegang1,2, Stefan Günther5, Patrick O Humbert6,7, Eunjee Lee8,9, Jun Zhu8,9, Andreas Weigert10, Praveen Mathoor10, Ilka Wittig2,11, Christoph Kruse1, Ralf P Brandes1,2. 1. Institute for Cardiovascular Physiology, Goethe-University, Theodor-Stern Kai 7, Frankfurt, Frankfurt am Main, Germany. 2. German Center for Cardiovascular Research (DZHK), Partner Site RheinMain, Theodor-Stern Kai 7, Frankfurt, Germany. 3. Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Ludwigstrasse 43, Bad Nauheim, Germany. 4. Department of Pediatrics, Molecular Genetics Section, University of Groningen, University Medical Center Groningen, Antonius Deusinglaan 1, AV Groningen, The Netherlands. 5. ECCPS Bioinformatics and Sequencing Facility, Goethe-University, Ludwigstrasse 43, Bad Nauheim, Germany. 6. Department of Biochemistry & Genetics, La Trobe Institute for Molecular Science, La Trobe University, Kingsbury Drive, Melbourne, Victoria, Australia. 7. Department of Clinical Pathology, Department of Molecular Biology and Biochemistry, The University of Melbourne, Grattan Street, Parkville, Victoria, Australia. 8. Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Pl, New York, NY, USA. 9. Sema4 Genomics, a Mount Sinai Venture, 333 Ludlow Street, South tower 3rd floor, Stamford, CT, USA. 10. Institute of Biochemistry I-Pathobiochemistry, Goethe-University, Frankfurt, Theodor-Stern Kai 7, Frankfurt am Main, Germany. 11. Functional Proteomics, SFB815 Core Unit, Medical School, Goethe University, Frankfurt, Theodor-Stern Kai 7, Frankfurt am Main, Germany.
Abstract
AIMS: The protein Scrib (Scribble 1) is known to control apico-basal polarity in epithelial cells. The role of polarity proteins in the vascular system remains poorly characterized; however, we previously reported that Scrib maintains the endothelial phenotype and directed migration. On this basis, we hypothesized that Scrib has anti-atherosclerotic functions. METHODS AND RESULTS: Tamoxifen-induced Scrib-knockout mice were crossed with ApoE-/- knockout mice and spontaneous atherosclerosis under high-fat diet (HFD), as well as accelerated atherosclerosis in response to partial carotid artery ligation and HFD, was induced. Deletion of Scrib resulted in increased atherosclerosis development in both models. Mechanistically, flow- as well as acetylcholine-induced endothelium-dependent relaxation and AKT phosphorylation was reduced by deletion of Scrib, whereas vascular permeability and leucocyte extravasation were increased after Scrib knockout. Scrib immune pull down in primary carotid endothelial cells and mass spectrometry identified Arhgef7 (Rho Guanine Nucleotide Exchange Factor 7, βPix) as interaction partner. Scrib or Arhgef7 down-regulation by siRNA reduced the endothelial barrier function in human umbilical vein endothelial cells. Gene expression analysis from murine samples and from human biobank material of carotid endarterectomies indicated that loss of Scrib resulted in endothelial dedifferentiation with a decreased expression of endothelial signature genes. CONCLUSIONS: By maintaining a quiescent endothelial phenotype, the polarity protein Scrib elicits anti-atherosclerotic functions. Published on behalf of the European Society of Cardiology. All rights reserved.
AIMS: The protein Scrib (Scribble 1) is known to control apico-basal polarity in epithelial cells. The role of polarity proteins in the vascular system remains poorly characterized; however, we previously reported that Scrib maintains the endothelial phenotype and directed migration. On this basis, we hypothesized that Scrib has anti-atherosclerotic functions. METHODS AND RESULTS:Tamoxifen-induced Scrib-knockout mice were crossed with ApoE-/- knockout mice and spontaneous atherosclerosis under high-fat diet (HFD), as well as accelerated atherosclerosis in response to partial carotid artery ligation and HFD, was induced. Deletion of Scrib resulted in increased atherosclerosis development in both models. Mechanistically, flow- as well as acetylcholine-induced endothelium-dependent relaxation and AKT phosphorylation was reduced by deletion of Scrib, whereas vascular permeability and leucocyte extravasation were increased after Scrib knockout. Scrib immune pull down in primary carotid endothelial cells and mass spectrometry identified Arhgef7 (Rho Guanine Nucleotide Exchange Factor 7, βPix) as interaction partner. Scrib or Arhgef7 down-regulation by siRNA reduced the endothelial barrier function in human umbilical vein endothelial cells. Gene expression analysis from murine samples and from human biobank material of carotid endarterectomies indicated that loss of Scrib resulted in endothelial dedifferentiation with a decreased expression of endothelial signature genes. CONCLUSIONS: By maintaining a quiescent endothelial phenotype, the polarity protein Scrib elicits anti-atherosclerotic functions. Published on behalf of the European Society of Cardiology. All rights reserved.