April 2014
Volume 55, Issue 13
Free
ARVO Annual Meeting Abstract  |   April 2014
Retina formation requires suppression of BMP and Activin pathways in pluripotent cells
Author Affiliations & Notes
  • Kimberly Wong
    Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY
    Opthalmology and Center for Vision Research, SUNY Upstate Medical University and SUNY Eye Institute, Syracuse, NY
  • Michael A Trembley
    Pharmacology and Physiology, Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, Rochester, NY
  • Andrea Sophia Viczian
    Opthalmology and Center for Vision Research, SUNY Upstate Medical University and SUNY Eye Institute, Syracuse, NY
  • Footnotes
    Commercial Relationships Kimberly Wong, None; Michael Trembley, None; Andrea Viczian, None
  • Footnotes
    Support None
Investigative Ophthalmology & Visual Science April 2014, Vol.55, 4034. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Kimberly Wong, Michael A Trembley, Andrea Sophia Viczian; Retina formation requires suppression of BMP and Activin pathways in pluripotent cells. Invest. Ophthalmol. Vis. Sci. 2014;55(13):4034.

      Download citation file:


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

      ×
  • Supplements
Abstract

Purpose: Retina formation requires the correct spatiotemporal expression of key regulatory proteins. Signaling through the bone morphogenetic protein (BMP) pathway represses the formation of neural and retinal fates. It has been shown that Noggin acts as a morphogen to specify neural cell types at low concentrations, and retinal cell types at higher concentrations. The aim of our study is to determine if the higher concentration of Noggin affects signaling pathways other than BMP.

Methods: We treated pluripotent Xenopus laevis tissue (animal caps) with chemical inhibitors and function-altering components of the BMP and Activin/Nodal signaling pathway. Animal caps were removed from the embryos at the blastula stage and cultured until neural plate stage. Their effect on retina formation was determined using the Animal Cap Transplant (ACT) assay, in which the animal caps were transplanted into the eye field of sibling embryos. Signaling activity was determined by Western blot and semi-quantitative PCR (RT-PCR) to measure downstream protein and gene target expression.

Results: Overexpressing Noggin in animal caps resulted in a concentration-dependent suppression of both Smad1 and Smad2 phosphorylation, which act downstream of BMP and Activin/Nodal receptors, respectively. This caused a decrease in downstream transcriptional ability, reflected by the reduced expression of mesodermal marker, Xbra, and endothelial marker, Xk81. However, we also observed that Cerberus was less effective at blocking Smad1/5/8 phosphorylation, yet it can specify retina as efficiently as Noggin in ACT assays. Cerberus has been shown to block the Activin/Nodal pathway, as well as the BMP pathway, suggesting that there is a specific balance between the two pathways that is required to direct a retinal fate. The use of dominant negative BMP and activin receptors revealed that retinal specification was increased when both pathways were inhibited simultaneously. Similar results were observed when the chemical inhibitors Dorsomorphin and SB431542 were used to inhibit Smad1 and Smad2/3 phosphorylation, respectively.

Conclusions: Thus, the dual inhibition of BMP and activin pathways promotes retinal specification in Xenopus tissue. Future studies will translate these findings to a mammalian culture assay, in order to efficiently produce a large percentage of retinal cells in vitro.

Keywords: 688 retina • 497 development  
×
×

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.

×