title: Somatic GNAQ Mutation is Enriched in Brain Endothelial Cells in Sturge-Weber Syndrome.
abstract: Sturge-Weber syndrome (SWS) is a rare congenital neurocutaneous disorder characterized by facial and extracraniofacial capillary malformations and capillary-venule malformations in the leptomeninges. A somatic mosaic mutation in GNAQ (c.548G>A; p.R183Q) was found in SWS brain and skin capillary malformations. Our laboratory showed endothelial cells in skin capillary malformations are enriched for the GNAQ mutation. The purpose of this study is to determine whether the GNAQ mutation is also enriched in endothelial cells in affected SWS brain.
  
  
  
  Two human SWS brain specimens were fractionated by fluorescence-activated cell sorting into hematopoietic (CD45), endothelial (CD31, VE-Cadherin, and vascular endothelial growth factor receptor 2), and perivascular (platelet-derived growth factor receptor beta) cells and cells negative for all markers. The sorted cell populations were analyzed for GNAQ p.R183Q mutation by droplet digital polymerase chain reaction. SWS patient-derived brain endothelial cells were selected by anti-CD31-coated magnetic beads and cultured in endothelial growth medium in vitro.
  
  
  
  The GNAQ p.R183Q mutation was present in brain endothelial cells in two SWS specimens, with mutant allelic frequencies of 34.7% and 24.0%. Cells negative for all markers also harbored the GNAQ mutation. The mutant allelic frequencies in these unidentified cells were 9.2% and 8.4%. SWS patient-derived brain endothelial cells with mutant allelic frequencies of 14.7% and 21% survived and proliferated in vitro.
  
  
  
  Our study provides evidence that GNAQ p.R183Q mutation is enriched in endothelial cells in SWS brain lesions and thereby reveals endothelial cells as a source of aberrant Gαq signaling. This will help to understand the pathophysiology of SWS, to discover biomarkers for predicting cerebral involvement, and to develop therapeutic targets to prevent neurological impairments in SWS.
authors.affiliation: Vascular Biology Program, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts; Department of Surgery, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts.
authors.forename: Lan
authors.initials: L
authors.lastname: Huang
authors.affiliation: Department of Plastic and Oral Surgery, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts.
authors.forename: Javier A
authors.initials: JA
authors.lastname: Couto
authors.affiliation: Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts.
authors.forename: Anna
authors.initials: A
authors.lastname: Pinto
authors.affiliation: Department of Pathology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts.
authors.forename: Sanda
authors.initials: S
authors.lastname: Alexandrescu
authors.affiliation: Department of Neurosurgery, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts.
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Madsen
authors.affiliation: Department of Plastic and Oral Surgery, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts; Vascular Anomalies Center, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts.
authors.forename: Arin K
authors.initials: AK
authors.lastname: Greene
authors.affiliation: Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Sahin
authors.affiliation: Vascular Biology Program, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts; Department of Surgery, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts. Electronic address: joyce.bischoff@childrens.harvard.edu.
authors.forename: Joyce
authors.initials: J
authors.lastname: Bischoff
mesh_terms: D001921:Brain / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D002478:Cells, Cultured; D002648:Child; D042783:Endothelial Cells / Q000378:metabolism* / Q000473:pathology; D005434:Flow Cytometry; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D007223:Infant; D008297:Male; D018613:Microscopy, Confocal; D009154:Mutation; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D013341:Sturge-Weber Syndrome / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology / Q000601:surgery
chemical_list: C554061:GNAQ protein, human; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D043802:GTP-Binding Protein alpha Subunits, Gq-G11
keywords: GNAQ; Sturge–Weber syndrome; capillary malformation; ddPCR; endothelial cell