April 2011
Volume 52, Issue 14
Free
ARVO Annual Meeting Abstract  |   April 2011
Endogenous Production of 1,25(OH)2D3 by Ocular Barrier Cells
Author Affiliations & Notes
  • Jawaher A. Alsalem
    Academic Unit of Ophthlamology, School of Immunity and Infection,
    University of Birmingham, Birmingham, United Kingdom
  • Radhika Susarla
    Academic Unit of Ophthlamology, School of Immunity and Infection,
    University of Birmingham, Birmingham, United Kingdom
  • Miguel Coca-Prados
    Department of Ophthalmology and Visual Science, Yale University, New Haven, Connecticut
  • Rosemary Bland
    The Biomedical Research Institute, University of Warwick, Coventry, United Kingdom
  • Elizabeth A. Walker
    Center for Endocrinology, Diabetes, and Metabolism,
    University of Birmingham, Birmingham, United Kingdom
  • Saaeha Rauz
    Academic Unit of Ophthlamology, School of Immunity and Infection,
    University of Birmingham, Birmingham, United Kingdom
  • Graham R. Wallace
    Academic Unit of Ophthlamology, School of Immunity and Infection,
    University of Birmingham, Birmingham, United Kingdom
  • Footnotes
    Commercial Relationships  Jawaher A. Alsalem, None; Radhika Susarla, None; Miguel Coca-Prados, None; Rosemary Bland, None; Elizabeth A. Walker, None; Saaeha Rauz, None; Graham R. Wallace, None
  • Footnotes
    Support  Action Medical Research; The Academic Unit of Ophthalmology is supported by the birmingham Eye Foundation (Registered (UK) Charity 257549)
Investigative Ophthalmology & Visual Science April 2011, Vol.52, 2915. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Jawaher A. Alsalem, Radhika Susarla, Miguel Coca-Prados, Rosemary Bland, Elizabeth A. Walker, Saaeha Rauz, Graham R. Wallace; Endogenous Production of 1,25(OH)2D3 by Ocular Barrier Cells. Invest. Ophthalmol. Vis. Sci. 2011;52(14):2915.

      Download citation file:


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

      ×
  • Supplements
Abstract

Purpose: : There is an increasing evidence that many cells and tissues including those at barrier sites express the vitamin D receptor (VDR) and 1-alpha-hydroxylase (CYP27B1), the enzyme required to convert inactive 25(OH)D3 into active 1,25(OH)2D3 . These can activate and locally produce 1,25(OH)2D3, which functions as a potent immunomodulatory hormone. Blood-aqueous (ciliary body and iris) and blood-retinal barriers maintain an immune privileged environement in the eye. Corneal endothelium contributes to barrier function between corneal stroma and aqueous humor. This study aims to investigate the role of 1,25(OH)2D3 in ocular barrier function.

Methods: : Human adult retinal pigment epithelial (ARPE-19), non-pigmented ciliary body epithelium (ODM2), and corneal endothelial (HCEC-12) cell lines were cultured. Gene expression for elements of the vitamin D and Toll like receptor pathways were examined by conventional and real-time polymerase chain reaction (RT-PCR) both in the absence and presence of TLR ligands and vitamin D substrate (25(OH)D3). Protein expression was analysed by immunohistochemistry. Cytokine and 1,25(OH)2D3 production were measured by enzyme immunoassay.

Results: : ARPE-19, ODM2, HCEC-12 cells expressed mRNA for VDR, CYP27B1, and the catabolizing enzyme, 24-hydoxylase (CYP24A1). This was confirmed by immunohistochemistry in non-pigment ciliary body epithelium and corneal endothelium tissue sections and by immunofluorescence in ARPE-19 cells. ARPE-19 and HCEC-12 cells are able to convert 25(OH)D3 into active 1,25(OH)2D3 and HCEC-12 show higher levels than ARPE-19. ARPE-19 cells were responsive to TLR ligand stimulation but this did not have an effect on elements of vitamin D gene expression. Conversely, the addition of 25(OH)D3 did not influence cytokine production by these cells.

Conclusions: : Our data show for the first time that retinal pigment epithelial and corneal endothelial cells have the ability to convert inactive 25(OH)D3 into active 1,25(OH)2D3 and this is not influenced by TLR ligand stimulation. Vitamin D3 produced by ocular barrier cells may possibly play a role in ocular immune privilege.

Keywords: retinal pigment epithelium • ciliary body • cornea: endothelium 
×
×

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.

×