The effect of TGF-beta 1 on differential gene expression profiles in humancorneal epithelium studied by cDNA expression array

PURPOSE. TGF-betas regulate cell proliferation and differentiation, and the y play important roles in maintenance of corneal epithelium. However, the p recise function of TGF-betas in the corneal epithelium remains unclear. In this study, cDNA expression array technology was used to demonstrate the ef fect of TGF-beta1 on the simultaneous expression of a large number of genes in cultured human corneal epithelial cells (HCECs). The change in protein level expression of the specific genes influenced by TGF-beta1 was also inv estigated. METHODS. Human cDNA expression array technology was used to study the simul taneous expression of 1176 specific cellular genes in HCECs incubated with TGF-beta1 (10 ng/ml). Moreover, gene-specific semiquantitative reverse tran scription-polymerase chain reaction (RT-PCR) was used to confirm the gene e xpression pattern measured by the cDNA expression array. Western blot analy sis was used to examine protein expression of the specific genes in the pre sence or absence of TGF-beta1. RESULTS. TGF-beta1 significantly upregulated the expression of 19 genes and significantly downregulated ras-related protein, caspase 10, and beta4-int egrin in the treated HCECs. The expression of 277 genes including alpha3-in tegrin, PAI-2, transferrin receptor, and cyclin-D1 was studied. Semiquantit ative RT-PCR analysis confirmed the TGF-beta1-mediated changes in expressio n patterns of these genes. Furthermore, Western blot analysis revealed that TGF-beta1 remarkably decreased PAI-2, transferrin receptor, and integrin a lpha3, and increased caspase 10 on the protein level. CONCLUSIONS. TGF-beta1 regulates the expression of specific types of genes in HCECs. These results strongly suggest that TGF-beta1 is critically invol ved in the maintenance of the corneal epithelium through the control of a n etwork of various signal-transduction pathways.