VA-lip HSP47 knock down HSP47 expression in myofibroblasts and ameliorate bleomycin-induced skin fibrosis. (A-B) Primary skin fibroblasts isolated from naïve BALB/c mice (A) and NIH/3T3 (B) were stimulated with 5 ng/mL of rhTGF-β in the presence or absence of VA-lip containing scramble siRNA or VA-lip HSP47 for 12 hours. Hsp47 messenger RNA levels relative to Gapdh were determined using qPCR, and fold differences relative to those of unstimulated control cells are shown (n = 3/group). Data from one of 2 independent experiments with similar results are shown. (C-D) B6 mice were subcutaneously injected with bleomycin daily for 21 days. (C) On the next day of the last bleomycin treatment, mice were intravenously injected with VA-lip Dy647 at 3 times every 2 hours, and frozen sections of skin were prepared at 3 hours after the last injection. Fluorescence of VA-lip Dy647 (green) was visualized with DAPI (blue) counterstaining. The area in the white rectangle is magnified and is shown on the right side of the original image. Magnification, ×20 or ×40. Scale bar, 50 μm. (D) A group of mice were treated with VA-lip HSP47 at 3 times per week from day 1 of bleomycin treatment. The amount of collagen deposit in the fibrotic lesion or the intact skin from VA-lip HSP47–treated (n = 9) or untreated mice (n = 17) from 2 independent experiments was combined and is shown as means ± SEM. *P < .05; **P < .01. N.S., not significant.