EGF, EGF receptor, basic FGF, TGF beta-1, and IL-1 alpha mRNA in human corneal epithelial cells and stromal fibroblasts

We sought to determine whether human corneal epithelial cells and stromal fibroblasts synthesize messenger RNAs (mRNA) coding for epidermal growth factor (EGF), EGF receptor, basic fibroblast growth factor (basic FGF), transforming growth factor-beta 1 (TGF-beta 1), and interleukin-1 alpha (IL- 1α). Total cellular RNA was extracted from cultured stromal fibroblasts and ex vivo and cultured corneal epithelial cells. Oligo dt-primed complementary DNA (cDNA) was synthesized from each RNA sample. The polymerase chain reaction (PCR) was used to amplify sequences for EGF, EGF receptor, basic FGF, TGF-beta 1, IL-1 alpha, and beta actin from cDNA samples from each cell type. Southern blots of the PCR products were probed with oligonucleotides complementary to internal sequences within each of the amplified products. The amplification products were shown to be specific. For each modulator, the amplification product of the expected size was identified with at least one specific, alternative amplification product. The alternative splicing products suggest that there may be alternative mRNA splicing for each of the modulators studied. Differences were noted in the IL-1 alpha specific amplification products in stromal fibroblasts compared to corneal epithelial cells. EGF and EGF receptor mRNA production in human corneal epithelial cells and stromal fibroblasts suggest an autocrine role for EGF in the physiology of each of these cell types.