Induction of collagen expression in fibroblasts by anti-AT
R and anti-ET
R Ab-positive SSc-IgG . Skin fibroblasts of healthy donors increase expression of type I collagen with anti-AT1R and anti-ETAR Ab positive SSc-IgG. (A) Expression of type I collagen analyzed with immunocytochemistry. Collagen expression is shown in green, and nucleic acid DAPI stain, in blue. Bar indicates 50 μm; shown are representative pictures. (B) Significant increase in type I collagen with SSc-IgG versus NC-IgG (NC-IgG n = 4 and SSc-IgG n = 5, P < 0.05). Relative fluorescence intensity was analyzed and normalized to cell number for each sample. Mean and SEM, *P < 0.05. (C) Collagen expression (type I collagen) shows a significant correlation to anti-ETAR Ab levels and a trend to anti-AT1R Ab levels (NC-IgG, n = 3;, SSc-IgG, n = 5;, total n = 8; P < 0.05). Spearman correlation.