Growth factor effects on the expression of collagenase and TIMP-1 in periodontal ligament cells

The fibroblast is a prominent cellular component of the periodontal ligament. It is believed to play an important role in collagen metabolism in health and disease. The turnover of collagen in the periodontal ligament is believed to be controlled by the balance between collagen synthesis and degradation. The family of matrix metalloproteinases and their inhibitors is one of the mechanisms which regulates this balance. The factors that regulate the synthesis of collagenase and its inhibitor, TIMP-1, by the periodontal ligament cell are poorly understood. The present study was undertaken to assess the effect of interleukin-1 beta (IL-1 beta), platelet-derived growth factor (PDGF), and transforming growth factor-beta 1 (TGF-beta) on the expression of collagenase (MMP-1) and TIMP-1 mRNA in periodontal derived fibroblasts using reverse transcription polymerase chain reaction (RT-PCR). Early passage periodontal ligament derived fibroblasts were treated with IL-1 beta (10 and 100 pg/ml), two isoforms of PDGF, -AA and -BB (4 and 20 ng/ml) and TGF-beta (1 and 10 ng/ml). Treatment with growth factors from 2 to 24 hours revealed that the largest effects on MMP-1 mRNA occurred after 24 hours. IL-1 beta induced a 5 to 9 fold increase in MMP-1 mRNA. The two isoforms of PDGF had less of an effect (3 to 5 fold) on MMP-1 mRNA whereas TGF-beta induced a 25 to 50% decrease in the expression of this message. None of the growth factors had an effect on TIMP-1 mRNA expression.(ABSTRACT TRUNCATED AT 250 WORDS)