title: Gene expression and functional annotation of the human ciliary body epithelia.
abstract: OBJECTIVE
  The ciliary body (CB) of the human eye consists of the non-pigmented (NPE) and pigmented (PE) neuro-epithelia. We investigated the gene expression of NPE and PE, to shed light on the molecular mechanisms underlying the most important functions of the CB. We also developed molecular signatures for the NPE and PE and studied possible new clues for glaucoma.
  
  
  METHODS
  We isolated NPE and PE cells from seven healthy human donor eyes using laser dissection microscopy. Next, we performed RNA isolation, amplification, labeling and hybridization against 44×k Agilent microarrays. For microarray conformations, we used a literature study, RT-PCRs, and immunohistochemical stainings. We analyzed the gene expression data with R and with the knowledge database Ingenuity.
  
  
  RESULTS
  The gene expression profiles and functional annotations of the NPE and PE were highly similar. We found that the most important functionalities of the NPE and PE were related to developmental processes, neural nature of the tissue, endocrine and metabolic signaling, and immunological functions. In total 1576 genes differed statistically significantly between NPE and PE. From these genes, at least 3 were cell-specific for the NPE and 143 for the PE. Finally, we observed high expression in the (N)PE of 35 genes previously implicated in molecular mechanisms related to glaucoma.
  
  
  CONCLUSIONS
  Our gene expression analysis suggested that the NPE and PE of the CB were quite similar. Nonetheless, cell-type specific differences were found. The molecular machineries of the human NPE and PE are involved in a range of neuro-endocrinological, developmental and immunological functions, and perhaps glaucoma.
authors.affiliation: Department of Clinical and Molecular Ophthalmogenetics, the Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands.
authors.forename: Sarah F
authors.initials: SF
authors.lastname: Janssen
authors.forename: Theo G M F
authors.initials: TG
authors.lastname: Gorgels
authors.forename: Koen
authors.initials: K
authors.lastname: Bossers
authors.forename: Jacoline B
authors.initials: JB
authors.lastname: Ten Brink
authors.forename: Anke H W
authors.initials: AH
authors.lastname: Essing
authors.forename: Martijn
authors.initials: M
authors.lastname: Nagtegaal
authors.forename: Peter J
authors.initials: PJ
authors.lastname: van der Spek
authors.forename: Nomdo M
authors.initials: NM
authors.lastname: Jansonius
authors.forename: Arthur A B
authors.initials: AA
authors.lastname: Bergen
mesh_terms: D002924:Ciliary Body / Q000166:cytology*; D020869:Gene Expression Profiling; D005901:Glaucoma / Q000235:genetics; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D010857:Pigment Epithelium of Eye / Q000166:cytology* / Q000378:metabolism*