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Microarray study of limbal epithelial crypt demonstrates its putative limbal stem cell niche characteristics
Author(s) -
KULKARNI B,
FOSTER T,
YEUNG AM,
TIGHE P,
HOPKINSON A,
DUA HS
Publication year - 2008
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2008.4232.x
Subject(s) - stem cell , biology , gene , dna microarray , gene expression , integrin , stem cell marker , limbal stem cell , microbiology and biotechnology , cell , genetics , epithelium , corneal epithelium
Purpose We have discovered a novel anatomical structure at the limbus, termed the Limbal Epithelial crypt (LEC). Previous anatomical and immunohistological studies suggest its potential as the limbal stem cell niche. We aim to characterise the differential gene expression of the LEC by microarrays with a view to finding putative stem cell marker(s). Methods Frozen tissue blocks of corneoscleral buttons dissected from cadaver eyes were cryosectioned. These tissue sections from different ocular surface regions were laser microdissected. Extracted RNA was amplified & hybridized to microarray chips. Raw data obtained with Genepix Pro6 software was filtered, normalized & analysed on BASE, TMeV & Jexpresspro software. Unpaired T‐Test, Significance Analysis of Microarrays and k‐means clustering were performed on the data. Quantitative gene expression analysis (qPCR) was performed on the genes of interest. Results 150 differentially expressed genes in the LEC were obtained(p ≤ 0.01). These genes were clustered according to stem cell related functions. qPCR was performed on the Integrin Beta 1 binding protein gene (ITGB1BP1). The protein expressed by this gene specifically binds to Beta 1 Integrin (ITGB1) which is a cell adhesion molecule, is predominantly an inhibitor of cell proliferation and has a role in maintaining stem cells in their niche. These genes were significantly expressed in the LEC (P=0.03). Conclusion The constituents of the LEC are stem cells with neighbouring niche cells, hence representing a Limbal Epithelial Stem Cell niche.