[Effect of cyclic stretch with different amplitudes on the transformation of normal skin fibroblasts into hypertrophic scar fibroblasts].

To explore the role of cyclic stretch with different amplitudes on the transformation of normal skin fibroblasts (NSFB) into hypertrophic scar fibroblasts (HSFB).NSFB and HSFB were cultured in vitro. Cyclic stretch with 10%, 15% and 20% amplitude was applied for 24 h on NSFB of experimental groups (Group N10%,Group N15% and Group N20%). And control groups (groups N0 and H0), NSFB and HSFB were cultured without stretch. Cell Counting Kit-8 method was used to detect the proliferation of fibroblasts. The gene expressions of integrin β1, P130Cas, TGF-β1, COL1A1 and COL3 A1 were detected by real-time polymerase chain reaction (PCR). And the protein expressions of TGF-β1, collagen types I and III were detected by enzyme-linked immunosorbent assay.Cyclic stretch had stimulatory effect on cell proliferation. The proliferation capacity of group N10% was higher than that of group N20% (0.91 ± 0.09 vs 0.8 ± 0.07, P < 0.05). Cyclic stretch could induce increased levels of gene expression.Gene expression levels of integrin β1, P130Cas, TGF-β1, COL1A1 and COL3 A1 in group N10% was higher than those in group N20% (3.14 ± 0.24, 5.01 ± 0.49, 1.55 ± 0.08, 2.38 ± 0.08, 1.37 ± 0.11 vs 1.78 ± 0.32, 3.07 ± 0.41, 1.18 ± 0.05, 1.97 ± 0.05, 1.26 ± 0.19; all P < 0.05). Cyclic stretch could stimulate NSFB to secrete TGF-β1. The protein level of TGF-β1 in group N10% was higher than that in group N20% ((459 ± 12.96) vs (372 ± 10.49) pg/ml, P < 0.05). The protein levels of collagen types I and III in experiment groups were higher than those in group N0 and lower than those in group H0 (all P < 0.05). The protein level of collagen type I in group N10% was higher than that in group N20% ((12.66 ± 1.16) vs (11.23 ± 0.75) ng/ml, P < 0.05).NSFB loaded cyclic stretch with 10% amplitude could exhibit some biological characteristics of HSFB. And cyclic stretch with optimal amplitude might transform NSFB into HSFB.