Purchase this article with an account.
H. Qi, S. C. Pflugfelder, D.-Q. Li; Expression Pattern of Stem Cell and Differentiation Markers by Human Bulbar Conjunctival Epithelium. Invest. Ophthalmol. Vis. Sci. 2009;50(13):2623.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Human ocular surface is covered with highly specialized conjunctival, limbal and corneal epithelia, which share many of the basic features of the epidermal system. Unlike the stratified corneal epithelium, the conjunctival epithelium consists of morphologically distinct stratified non-goblet epithelial cells as well as mucin-secreting goblet cells. The purpose of this study was to investigate the differential immuno-localization of stem/progenitor cell associated and differentiation markers in the human bulbar conjunctival epithelium.
Immunofluorescent staining and laser scanning confocal microscopy were performed on frozen sections of fresh human bulbar conjunctiva
We found that corneal specific cytokeratin (CK) 3 was not expressed by the bulbar conjunctival epithelial cells. In contrast, CK4 and CK7 were only expressed by the superficial cells of bulbar conjunctival epithelium. CK14 and CK15 were confined to the basal cell layer of bulbar conjunctival epithelium, but they were expressed by all layers of limbal epithelia. CK19 was strongly expressed by all layers of the bulbar conjunctival epithelium, but weakly expressed in the limbus. Basal conjunctival epithelial cells strongly expressed limbal stem/progenitor cell associated markers, including ABCG2, p63, nerve growth factor (NGF) with its receptors tyrosine kinase receptor A (TrkA) and neurotrophin low-affinity receptor p75NTR, glial cell-derived neurotrophic factor (GDNF) with its receptor GDNF family receptor alpha 1 (GFR-1), integrin β1, -enolase and epidermal growth factor receptor (EGFR). The differentiation associated markers nestin, E-cadherin and involucrin were not expressed by these basal cells.
These findings indicate that the epithelia covering the limbal and conjunctival surfaces have different phenotypes that can be mainly distinguished by their differential expression of CKs. The molecular markers expressed by the basal layer of bulbar conjunctival epithelium support the hypothesis that the basal cells may be a source of progenitor cells for the conjunctival epithelium.
This PDF is available to Subscribers Only