September 2016
Volume 57, Issue 12
Open Access
ARVO Annual Meeting Abstract  |   September 2016
The matricellular protein CCN1 defines mural cell coverage and integrity of retinal vessels and reduces their susceptibility to pathological neovascular growth through the Wnt pathway
Author Affiliations & Notes
  • Brahim Chaqour
    Cell Biology and Ophthalmology, SUNY Downstate Medical Center, Brooklyn, New York, United States
  • Maria B Grant
    Ophthalmology, Indiana University, Indiana, Indiana, United States
  • Menna Elaskandrany
    Cell Biology and Ophthalmology, SUNY Downstate Medical Center, Brooklyn, New York, United States
  • Sangmi Lee
    Cell Biology and Ophthalmology, SUNY Downstate Medical Center, Brooklyn, New York, United States
  • Footnotes
    Commercial Relationships   Brahim Chaqour, None; Maria Grant, None; Menna Elaskandrany, None; Sangmi Lee, None
  • Footnotes
    Support  NIH Grant EY022091
Investigative Ophthalmology & Visual Science September 2016, Vol.57, 4530. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Brahim Chaqour, Maria B Grant, Menna Elaskandrany, Sangmi Lee; The matricellular protein CCN1 defines mural cell coverage and integrity of retinal vessels and reduces their susceptibility to pathological neovascular growth through the Wnt pathway. Invest. Ophthalmol. Vis. Sci. 2016;57(12):4530.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose : Crosstalk between endothelial cells (ECs) and their ensheathing mural cells (e.g., smooth muscle (SM) cells and pericytes) determines the proliferation status of ECs and contributes to blood retinal barrier maintenance/integrity. We hypothesize that the matricellular CCN1, a highly angiogenic heparin- and integrin-binding extracellular matrix protein, regulates endothelial-mural cell interactions to allow for proper growth and/or regeneration of retinal blood vessels under normal and ischemic conditions.

Methods : EC- and SM-specific loss-of-function of CCN1 was carried out by crossing mice carrying floxed CCN1 alleles with either tamoxifen-activated Cdh5(PAC)-CreERT2 or SM-Myh11-CreERT2 mice respectively. Retinal vascular phenotypes were determined by immunohistochemistery in neonates left untreated or subjected to oxygen-induced retinopathy (OIR) i.e., exposure to 75% oxygen for 5 days at postnatal day 7 followed by normoxia for 5 days. Gene expression was quantified at the mRNA and protein levels by quantitative real time PCR and densitometric measurements of Western blot protein bands.

Results : The CCN1 protein is intensely expressed in angiogenic ECs at the leading front of actively growing vessels in the developing mouse retina. Under ischemic conditions, the CCN1 protein becomes minimally expressed in ECs but highly expressed in the ensheathing SM alpha-actin- NG2-positive mural cells during the proliferative phase of OIR. Endothelial deletion of CCN1 in mice induces EC hyperplasia, loss of pericyte coverage and disruption of retinal barrier function. Conversely, while SM-specific deletion of CCN1 causes no overt vascular defects during development of retinal vessels, it significantly reduces neovascular growth following OIR. SM-specific loss of CCN1 increased SM/pericyte survival, enhanced endothelial-pericyte associations and subsequently neovessel stabilization through Wnt-dependent signaling mechanisms.

Conclusions : The autocrine and paracrine activities of CCN1 differentially regulate EC growth and mural cell recruitment and behavior; which determines vessel stabilization and integrity in physiological and pathological conditions. Thus, CCN1 is useful in developing specific gain- or loss-of-function strategies for treatment of neovacular diseases of the retina.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×