Fig. 2.

A: 2-dimensional gel electrophoresis (2-DE) of proteins from lung fibroblasts. Lung fibroblasts transfected with pcDNA3 (left) or CTGF (middle) and nontransfected SSc lung fibroblasts (right) were collected with PBS and solubilized in sample rehydration buffer. First-dimension electrophoresis was performed using gradient strips with immobilized pH 4–7, and 2-DE was carried out on NuPAGE 7% Tris-Acetate gel. Indicated spots represent proteins identified by mass spectrometric analysis (MS) that were upregulated (U1-U8) or downregulated (D9-D13) in cells transfected with CTGF compared with vector-transfected control cells. Five normalized protein spots corresponding to vimentin (circled in each panel) were selected as housekeeping proteins. Transfection efficiency was determined by immunoblotting of cell lysates with anti-CTGF antibody (B). The experiment was performed 3 times, and representative images of silver-stained gels are presented. IPG, immobilized pH gradient.