Endothelial GNAQ p.R183Q Increases ANGPT2 (Angiopoietin-2) and Drives Formation of Enlarged Blood Vessels

Arterioscler Thromb Vasc Biol. 2022 Jan;42(1):e27-e43. doi: 10.1161/ATVBAHA.121.316651. Epub 2021 Oct 21.

Abstract

Objective: Capillary malformation (CM) occurs sporadically and is associated with Sturge-Weber syndrome. The somatic mosaic mutation in GNAQ (c.548G>A, p.R183Q) is enriched in endothelial cells (ECs) in skin CM and Sturge-Weber syndrome brain CM. Our goal was to investigate how the mutant Gαq (G-protein αq subunit) alters EC signaling and disrupts capillary morphogenesis. Approach and Results: We used lentiviral constructs to express p.R183Q or wild-type GNAQ in normal human endothelial colony forming cells (EC-R183Q and EC-WT, respectively). EC-R183Q constitutively activated PLC (phospholipase C) β3, a downstream effector of Gαq. Activated PLCβ3 was also detected in human CM tissue sections. Bulk RNA sequencing analyses of mutant versus wild-type EC indicated constitutive activation of PKC (protein kinase C), NF-κB (nuclear factor kappa B) and calcineurin signaling in EC-R183Q. Increased expression of downstream targets in these pathways, ANGPT2 (angiopoietin-2) and DSCR (Down syndrome critical region protein) 1.4 were confirmed by quantitative PCR and immunostaining of human CM tissue sections. The Gαq inhibitor YM-254890 as well as siRNA targeted to PLCβ3 reduced mRNA expression levels of these targets in EC-R183Q while the pan-PKC inhibitor AEB071 reduced ANGPT2 but not DSCR1.4. EC-R183Q formed enlarged blood vessels in mice, reminiscent of those found in human CM. shRNA knockdown of ANGPT2 in EC-R183Q normalized the enlarged vessels to sizes comparable those formed by EC-WT.

Conclusions: Gαq-R183Q, when expressed in ECs, establishes constitutively active PLCβ3 signaling that leads to increased ANGPT2 and a proangiogenic, proinflammatory phenotype. EC-R183Q are sufficient to form enlarged CM-like vessels in mice, and suppression of ANGPT2 prevents the enlargement. Our study provides the first evidence that endothelial Gαq-R183Q is causative for CM and identifies ANGPT2 as a contributor to CM vascular phenotype.

Keywords: GTP-binding protein alpha subunits; Sturge-Weber syndrome; angiopoietin-2; endothelial cells; port wine stain.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Angiopoietin-2 / genetics
  • Angiopoietin-2 / metabolism*
  • Animals
  • Capillaries / abnormalities
  • Capillaries / metabolism*
  • Cells, Cultured
  • Child
  • Child, Preschool
  • Endothelial Progenitor Cells / metabolism*
  • Endothelial Progenitor Cells / pathology
  • Endothelial Progenitor Cells / transplantation
  • Female
  • GTP-Binding Protein alpha Subunits, Gq-G11 / genetics
  • GTP-Binding Protein alpha Subunits, Gq-G11 / metabolism*
  • Human Umbilical Vein Endothelial Cells / metabolism
  • Human Umbilical Vein Endothelial Cells / pathology
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Mice, Nude
  • Mutation
  • Neovascularization, Pathologic*
  • Phenotype
  • Phospholipase C beta / genetics
  • Phospholipase C beta / metabolism
  • Protein Kinase C / metabolism
  • Signal Transduction
  • Sturge-Weber Syndrome / genetics
  • Sturge-Weber Syndrome / metabolism*
  • Sturge-Weber Syndrome / pathology
  • Up-Regulation

Substances

  • ANGPT2 protein, human
  • Angiopoietin-2
  • GNAQ protein, human
  • Protein Kinase C
  • PLCB3 protein, human
  • Phospholipase C beta
  • GTP-Binding Protein alpha Subunits, Gq-G11