May 2006
Volume 47, Issue 13
Free
ARVO Annual Meeting Abstract  |   May 2006
Expression, Localization and Secretion of Phospholipase A2 in Human Conjunctival Goblet Cells
Author Affiliations & Notes
  • H.C. Turner
    Ophthalmology, Mount Sinai School of Medicine, New York, NY
  • J. Wolosin
    Ophthalmology, Mount Sinai School of Medicine, New York, NY
  • M. Taveras
    Ophthalmology, Mount Sinai School of Medicine, New York, NY
  • Footnotes
    Commercial Relationships  H.C. Turner, None; J. Wolosin, None; M. Taveras, None.
  • Footnotes
    Support  NIH Grant EY014878 and RPB, Inc.
Investigative Ophthalmology & Visual Science May 2006, Vol.47, 4949. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      H.C. Turner, J. Wolosin, M. Taveras; Expression, Localization and Secretion of Phospholipase A2 in Human Conjunctival Goblet Cells . Invest. Ophthalmol. Vis. Sci. 2006;47(13):4949.

      Download citation file:


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

      ×
  • Supplements
Abstract

Purpose: : Comparative corneal/conjunctival microarray analysis (Turner, ARVO 2004; #1462) identified group IIA secretory phospholipase A2 (sPLA2–IIA) a natural anti–microbial protein in tears, as a major component of the human conjunctival epithelium. Secretory PLA2 enzymes perform a wide range of other biological functions in a tissue–dependent manner that, in particular, includes an important role as a powerful proinflammatory mediator (Int Arch Allergy Immunol. 2003; 131:153). Given its high expression level in the conjunctiva, we examined the cellular distribution of sPLA2–IIA protein at the histological level to establish whether there is an anatomical basis for secretory activity.

Methods: : Freshly frozen and formalin fixed, paraffin–embedded conjunctival tissue sections were probed with a mouse monoclonal antibody to human sPLA2 and visualized with an Alexa 488–conjugated secondary antibody using epiflourescent and confocal microscopy.

Results: : sPLA2–IIA was distributed in both Goblet (Gb) and non–Goblet (nGb) cells in vesicular structures. Staining intensity demonstrated that the majority of the enzyme was accumulated in the Goblet cell. In immature subsurface Gbs, the vesicles were dramatically concentrated in full proximity to the cell membrane. In surface Gbs undergoing degranulation, numerous vesicle profiles were observed migrating towards the cell secretory pit while vesicular density at the membrane wall was markedly reduced. Within the nGb lineage, sPLA2–IIA vesicles in the subsurface cells were also localized to the plasma membrane. However, in the superficial cells, the vesicles have migrated to the sub–apical cytosolic space.

Conclusions: : This study reveals for the first time the presence of a vigorous non–mucin protein secretory activity in a Goblet cell. The results additionally suggest that the conjunctiva may be a substantial source of tear sPLA2–IIA vis a vis the assumed lacrimal gland source. The relative concentration and secretory activities of these two tissues deserve to be investigated.

Keywords: conjunctiva • cornea: tears/tear film/dry eye • gene microarray 
×
×

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.

×