Effects of Interleukin-4 on Extracellular Matrix Gene Expression in Normal Skin Fibroblasts Cultures

ABSTRACT

BACKGROUND: Interleukin-4(IL-4) is a 20 kDa glycoprotein and is now known to possess fibrogenic activities. OBJECTIVE: The purpose of this study is to evaluate the effect of IL4 on the extracellular matrix gene expression. METHODS: Quantitation of collagenous protein synthesis, Northern and dot-blot hybridization, transfection experiments and CAT assay in normal human skin fibroblasts were done. RESULTS: Maximal elevation of collagen synthesis was presented at the concentration of IL-4 being S.Ong/ml. In Northern and dot-blot analysis, each level of type I collagens and fibronectin mRNA increased 3.0, and 2.8-fold, respectively in IL4 treated fibroblasts. In CAT to c assay, the percentage of acetylation was 8.3% in the untreated control group and 23.1% in 5.Ong/ml of the IL-4 treated group in normal fibroblasts. The promoter activity was in creased 2.8-fold in II.4(5.Ong/ml) treated fibroblasts compared to the control groups. CONCLUSION: IL4 might be a fibrogenic cytokine that could be important in promoting the biogenesis of collagen proteins. This could be due to increased transcription.