Figure 6.

Quantitative effect of interleukin (IL)‐13 and protein kinase B (Akt) inhibitor on the expression of matrix metalloproteinase‐1 (MMP‐1) in normal and scleroderma‐involved dermal fibroblasts in the presence of tumour necrosis factor (TNF)‐α. Three normal fibroblast lines and three scleroderma fibroblasts lines from involved skin were either treated alone with IL‐13 or pretreated with Akt‐inh and IL‐13 followed by stimulation with TNF‐α. Supernatants were analysed by enzyme‐linked immunosorbent assay (ELISA) for MMP‐1 production. Data are expressed as stimulation index by dividing MMP‐1 of treated fibroblast by the MMP‐1 of the vehicle treated fibroblast. P‐values were determined by analysis of variance (anova) where P < 0·05 is significant; *P < 0·05 when compared to normal fibroblasts treated with IL‐13 and TNF‐α; **P < 0·05 when compared to systemic sclerosis (SSc)‐involved fibroblasts treated with IL‐13 and TNF‐α.