EXPRESSION OF GROWTH-FACTOR MESSENGER-RNAS BY HUMAN TENONS CAPSULE FIBROBLASTS

By using the techniques of reverse transcriptase-polymerase chain reac tion (RT-PCR) and Southern hybridization, we demonstrated that human T enon's capsule fibroblasts in primary cultures, express the messenger RNA (mRNA) transcripts encoding transforming growth factor-beta 1 (TGF -beta 1), basic fibroblast growth factor (bFGF), and platelet-derived growth factor (PDGF), but not those coding for aFGF and TGF-beta 2. Tw o PCR products were obtained for TGF-beta 1:a major fragment of 161 ba se pairs that corresponded to the expected size, and a minor sequence of 400 base pairs. An antisense oligonucleotide probe specific for TGF -beta 1 detected only the band of 161 base pair of PCR-amplified seque nce. For bFGF, PDGF-A and PDGF-B, we obtained only a single PCR produc t with the anticipated length of 222, 225, and 217 base pairs, respect ively. Southern blotting experiments revealed that these PCR-amplified fragments were specific for the respective growth factors. The negati ve control experiments without template did not reveal any amplificati on. No product for aFGF or TGF-beta 2 was detected. By radioimmunoassa y, TGF-beta 1 protein was detected at the level of 24-30 pg ml(-1) per 2 million Tenon's fibroblasts during a 24-hour period in acid-activat ed conditioned medium. These results indicate that human Tenon's capsu le fibroblasts in primary cultures express TGF-beta 1 at the translati onal as well as at the transcriptional levels, and they also have the capacity to synthesize bFGF and PDGF. Considering the significant effe cts of bFGF, TGF-beta 1, and PDGF in wound healing response, these gro wth factors are implicated in tissue repair process after glaucoma fil tration surgery that contributes to the failure of the procedure. (C) 1996 Academic Press Limited