Abstract
Purpose: :
Epithelial Basement Membrane Dystrophy (EBMD) is a common corneal dystrophy characterized by faulty basement membranes that are thickened, multilaminar, and misdirected into the epithelium. The purpose of this study was to determine whether differences exist in the RNA expression of extracellular matrix (ECM) and adhesion genes between normal subjects and EBMD patients.
Methods: :
Human corneal epithelia, discarded after surgery, from both normal subjects and patients with EBMD were collected in TRIzol solution for RNA isolation. Genomic contamination was eliminated using TURBO DNase, and RNA was purified using RNeasy MinElute spin columns. Four normal and 4 EBMD samples were assayed. cDNA was prepared using RT2 First Strand kit. Real time PCR was performed for each sample on a 96-well PCR-Array pre-loaded with primers for extracellular matrix and adhesion molecules. All plates were analyzed using the same threshold for determining the amplification cycle number. A paired t-test with online Superarray proprietary software was used to compare expression between normal and EBMD samples. P<0.05 was considered statistically significant.
Results: :
Of the eighty-four genes on the array, 57 were detected in the epithelial samples; of these the four most highly expressed included catenins A1 and D1, TGFβ1 and TIMP1. In the EBMD group, TIMP1 was significantly upregulated by 2.19 fold (p=0.028). Several other genes showed changes in expression that did not reach significance. These included laminin 3, SPARC, and thrombospondin 1, which were upregulated by 1.82 fold (p=0.067), 1.84 fold (p=0.111), and 1.67 fold (p=0.106), respectively. TGFβ1 was downregulated by 1.58 fold (p=0.119). Variances across the samples for all of the noted genes were less than 1 SD.
Conclusions: :
This preliminary study indicates that differences may exist in expression of extracellular matrix and adhesion molecules between normal and EBMD corneas. Increasing the numbers of samples and validating the changes in altered expression by protein analysis are necessary.
Keywords: cornea: epithelium • cornea: basic science • cornea: clinical science