Interleukin-10(IL-10) was initially discovered and isolated on the basis of its ability to suppress cytokine by Thl helper T cell. Recently, the effect of IL-10 has been reported in cultured connective tissue cells.

To further investigate the mechanisms of IL-10 on extracellular matrix(ECM) homeostasis, we evaluated the expression of type I collagen and stromelysin-1 at the transcriptional level and also observed their promoters activities.

We examined that effect of the recombinant human IL-10 on the expression of genes involved in extracelluar matrix(ECM) synthesis and remodelimg in human dermal fibroblast cultures. Quantification of collagen synthesis, Northern blot analysis, transient transfection and a chloramphenicol acetyl transferase(CAT) assay were performed.

In studying the dose and time response effect of IL-10 on collagen synthesis, maximal reduction was seen at 1.0 ng/ml concentration and 24 hours incubation. The synthesis of type I collagen mRNA was downregulated, while stromelysin-1 gene expression was enhanced by IL-10. In the transient transfection and CAT assay, the type I collagen promoter/CAT reporter gene construct showed downregulation by IL-10, while the stromelysin-1 gene promoter activities were upregulated.

It is suggested that IL-10 differently regulates the transcriptional levels of type I collagen and stromelysin-1 gene and denoting IL-10 seems to take part in the homeostasis of ECM at pretranscriptional level.