Influence of Sex on Gene Expression in Human Corneal Epithelial Cells

Objectives. Sex-associated differences have been identified in the anatomy, physiology and pathophysiology of the human cornea. We hypothesize that many of these differences are due to fundamental variations in gene expression. Our objective in this study was to determine whether such differences do exist in human corneal epithelial cells both in vivo and in vitro. Methods. Human corneal epithelial cells were isolated from the corneoscleral rims of male and female donors. Cells were processed either directly for RNA extraction, or first cultured in phenol red-free keratinocyte serum free media. The RNA samples were examined for differentially expressed mRNAs by using of CodeLink Bioarrays and Affymetrix GeneChips. Data were analyzed with GeneSifter.Net software. Results. Our results demonstrate that sex significantly influences the expression of over 400 genes in human corneal epithelial cells in vivo. These genes are involved a broad spectrum of biological processes, molecular functions and cellular components, such as metabolic processes, DNA replication, cell migration, RNA binding, oxidoreductase activity and nucleoli. We also identified significant, sex-related effects on gene expression in human corneal epithelial cells in vitro. However, with few exceptions (e.g. X- and Y-linked genes), these sex-related differences in gene expression in vitro were typically different than those in vivo. Conclusions. Our findings support our hypothesis that sex-related differences exist in the gene expression of human corneal epithelial cells. Keywords: Female vesus Male. Gene expression in corneal epithelial cells was compared between females and males. RNA was isolated from female (n=3) and male (n= 3) donors. The RNA was then used to generate labeled cRNA, which was then hybridized to CodeLink Uniset Human Bioarrays and Affymetrix GeneChip Human Genome U133A 2.0 Arrays. CEL files for Affymetrix GeneChip Human Genome U133A 2.0 Arrays are lost.