shRNA targeting SFRP2 promotes the apoptosis of hypertrophic scar fibroblast

Hypertrophic scars result from a dysregulated process in wound healing. Although the basic mechanism is unclear, increased proliferation and decreased cell apoptosis are noticed in the development of hypertrophic scar. In previous study, we found that secreted frizzled-related protein 2 (SFRP2), which was associated with cell proliferation, apoptosis, and differentiation, was dramatically upregulated in hypertrophic scar (HS) tissue. In this study short hairpin RNA (shRNA) targeting SFRP2 was employed to characterize SFRP2 function in hypertrophic scar-derived fibroblasts (HSFb). Cell proliferation was assessed by MTT, dynamic growth curves, and BRDU assays. Meanwhile, Cell apoptosis was detected using fluorescence-activated cell sorting (FACS). Caspase-3 activity was assayed by spectrophotometry. Fibroblast populated collagen lattice (FPCL) model was employed to evaluate the contractility of HSFb. Further, real-time PCR and western blot were used to measure the mRNA and protein expressions of α-SMA in HSFb. In addition, mRNA levels of type I and III procollagen were assayed by quantitative real-time PCR. The results revealed that shRNA targeting SFRP2 significantly promoted the apoptosis of HSFb, while it had no effect on the cell proliferation. Decreased synthesis of a-smooth muscle actin (α-SMA) in HSFb and reduced contraction of fibroblasts in the FPCL model were observed. Quantitative RT-PCR suggested that the mRNAs of type I and III procollagen were significantly downregulated. In conclusion, as a novel anti-apoptosis gene, SPRP2 was present in hypertrophic scars. Importantly, shRNA targeting SFRP2 may provide a new approach to preventing the formation of HS.