title: Expression of the primary angle closure glaucoma (PACG) susceptibility gene PLEKHA7 in endothelial and epithelial cell junctions in the eye.
abstract: OBJECTIVE
  The role of the recently identified primary angle closure glaucoma (PACG) susceptibility gene, pleckstrin homology domain containing, family A member 7 (PLEKHA7), in PACG is unknown. PLEKHA7 associates with apical junctional complexes (AJCs) and is thus implicated in paracellular fluid regulation. We aimed to determine PLEKHA7's localization in the eye and its association with AJCs to elucidate its potential role in PACG.
  
  
  METHODS
  Total RNA from ocular tissues was isolated and analyzed by real-time PCR. Frozen and paraffin-embedded human globes were sectioned and used for immunohistochemistry and immunofluorescence analysis.
  
  
  RESULTS
  Specific PLEKHA7 expression was found in the muscles, vascular endothelium, and epithelium of the iris, ciliary body and ciliary processes, trabecular meshwork (TM), and choroid. PLEKHA7 expression in musculature and vascular endothelium was confirmed with smooth muscle marker, SMA, and endothelium marker, PECAM-1, respectively. At the above sites, PLEKHA7 colocalization was seen with adherens junction markers (E-cadherin and β-catenin) and tight junction markers (ZO-1).
  
  
  CONCLUSIONS
  Specific localization of PLEKHA7 was found within PACG-related structures (iris, ciliary body, and choroid) and blood-aqueous barrier (BAB) structures (posterior iris epithelium, nonpigmented ciliary epithelium, iris and ciliary body microvasculature). The association of PLEKHA7 with AJCs in the eye suggests a potential role for PLEKHA7 in PACG via fluidic regulation. Novel expression of PLEKHA7 was also seen in the ocular smooth muscles and vascular endothelia.
authors.affiliation: Singapore Eye Research Institute, Singapore Duke-NUS Graduate Medical School, Singapore.
authors.forename: Mei Chin
authors.initials: MC
authors.lastname: Lee
authors.affiliation: Singapore Eye Research Institute, Singapore.
authors.forename: Anita S Y
authors.initials: AS
authors.lastname: Chan
authors.affiliation: Singapore Eye Research Institute, Singapore.
authors.forename: Shuang Ru
authors.initials: SR
authors.lastname: Goh
authors.affiliation: Singapore General Hospital, Histology, Department of Pathology, Singapore.
authors.forename: Maryam Hazly
authors.initials: MH
authors.lastname: Hilmy
authors.affiliation: Singapore Eye Research Institute, Singapore Duke-NUS Graduate Medical School, Singapore.
authors.forename: Monisha E
authors.initials: ME
authors.lastname: Nongpiur
authors.affiliation: Institute of Molecular and Cell Biology, Agency for Science Technology and Research, Singapore Department of Biochemistry, National University of Singapore, Singapore.
authors.forename: Wanjin
authors.initials: W
authors.lastname: Hong
authors.affiliation: Singapore Eye Research Institute, Singapore Duke-NUS Graduate Medical School, Singapore Singapore National Eye Centre, Singapore Department of Ophthalmology, National University of Singapore, Singapore.
authors.forename: Tin
authors.initials: T
authors.lastname: Aung
authors.affiliation: Singapore Eye Research Institute, Singapore Institute of Molecular and Cell Biology, Agency for Science Technology and Research, Singapore Department of Physiology, National University of Singapore, Singapore.
authors.forename: Walter
authors.initials: W
authors.lastname: Hunziker
authors.affiliation: Singapore Eye Research Institute, Singapore Duke-NUS Graduate Medical School, Singapore Department of Ophthalmology, National University of Singapore, Singapore.
authors.forename: Eranga N
authors.initials: EN
authors.lastname: Vithana
mesh_terms: D000199:Actins / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D002478:Cells, Cultured; D002924:Ciliary Body / Q000098:blood supply / Q000473:pathology; D042783:Endothelial Cells / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism*; D019084:Fluorescent Antibody Technique, Indirect; D005786:Gene Expression Regulation / Q000502:physiology*; D020022:Genetic Predisposition to Disease; D015812:Glaucoma, Angle-Closure / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007365:Intercellular Junctions / Q000378:metabolism*; D007498:Iris / Q000098:blood supply / Q000473:pathology; D018613:Microscopy, Confocal; D009130:Muscle, Smooth / Q000378:metabolism; D010957:Plasmids; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D014162:Transfection; D062826:Zonula Occludens-1 Protein / Q000378:metabolism
chemical_list: C541116:ACTA2 protein, human; D000199:Actins; D015415:Biomarkers; D002352:Carrier Proteins; C533786:PLEKHA7 protein, human; D019408:Platelet Endothelial Cell Adhesion Molecule-1; C569042:TJP1 protein, human; D062826:Zonula Occludens-1 Protein
keywords: blood–ocular barrier; gene expression; glaucoma