Accumulation of secretory vesicles in the lacrimal gland epithelia is related to non-Sjögren's type dry eye in visual display terminal users

PLoS One. 2012;7(9):e43688. doi: 10.1371/journal.pone.0043688. Epub 2012 Sep 4.

Abstract

Previous observations in a rat model of a non-Sjögren's syndrome (non-SS) type of dry eye seen in users of visual display terminals (VDT) indicated that secretory vesicle (SV) accumulation in the lacrimal gland epithelia contributes to the condition. Here, to examine this possibility in humans, we compared the lacrimal gland histology and percent SV area in the cytoplasm of acinar epithelial cells using light microscopy and transmission electron microscopy, in patients with VDT work-related non-SS dry-eye (VDT group), SS-induced dry-eye, and autopsied normal controls. In addition, the VAMP8 (vesicle-associated membrane protein 8, an exocrine-pathway molecule) and Rab3D (mature vesicle marker) were histochemically examined in lacrimal gland tissue sections. The lacrimal gland acini were larger in the VDT group than in the SS group, and the percent SV area was significantly higher in the VDT group than in the normal controls (P = 0.021) or SS group (P = 0.004). Immunostaining revealed abnormal distributions of VAMP8 in the VDT and SS groups. Rab3D was more strongly expressed in the cytoplasm of acinar epithelial cells in the VDT group than in that of normal controls. The duration of VDT use was significantly longer in the VDT group than in the other groups. These findings suggest that excessive SV accumulation in the acinar epithelia may contribute to the reduced tear secretion in VDT users.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Biomarkers / metabolism
  • Case-Control Studies
  • Computer Terminals
  • Cytoplasm / metabolism
  • Cytoplasm / pathology*
  • Epithelial Cells / metabolism
  • Epithelial Cells / pathology*
  • Epithelium / metabolism
  • Epithelium / pathology
  • Female
  • Gene Expression
  • Humans
  • Lacrimal Apparatus / metabolism
  • Lacrimal Apparatus / pathology*
  • Lacrimal Apparatus / physiopathology
  • Male
  • Microscopy, Electron, Transmission
  • Middle Aged
  • R-SNARE Proteins / genetics
  • R-SNARE Proteins / metabolism
  • Secretory Vesicles / metabolism
  • Secretory Vesicles / pathology*
  • Sjogren's Syndrome / physiopathology
  • Xerophthalmia / metabolism
  • Xerophthalmia / pathology*
  • Xerophthalmia / physiopathology
  • rab3 GTP-Binding Proteins / genetics
  • rab3 GTP-Binding Proteins / metabolism

Substances

  • Biomarkers
  • R-SNARE Proteins
  • VAMP8 protein, human
  • RAB3D protein, human
  • rab3 GTP-Binding Proteins

Grants and funding

This work was supported by a grant from the Japanese Ministry of Education, Science, Sports and Culture (no. 24791877 to Mizuka Kamoi), and the Japanese Medical Association 2010 (to Yoko Ogawa). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.