The Effect Of Thymosin Beta4on The Collagen Synthesis And The Expression Of CTGF Of The Human Hypertrophic Scar Fibroblasts

Objective：In this study, thymosin beta4was applied to the human hypertrophic scarfibroblasts, then the secretion of type Ⅰ and Ⅲ collagen and the variation ofconnective tissue growth factor（CTGF） were observed in order to understand themechanism of thymosin beta4on the morbidity of pathological scar.Methods：Hypertrophic scar fibroblasts (HSFB) were obtained from patients who receivedplastic surgery (6months after injury), and then cultured in vitro using tissue culturemethod. The third to the sixth generation of HSFB were selected and intervened bythymosin beta4with various concentrations (0、0.05、0.1、1、5μg/mL) for six hoursin the serum-free medium. Several analysis methods were applied:(1) the secretion oftype Ⅰ, Ⅲ collagen from HSFB was assayed with ELISA method;(2) theexpression of CTGF mRNA was observed with RT-PCR;(3) the expression of CTGFprotein was detected by Western blot.Results：(1) Compared with the control group with the thymosin beta4concentrations of0μg/mL, the four experiment group with four different concentrations (0.05、0.1、1、5μg/mL) can inhibit the secreation of typeⅠ, Ⅲ collagen, and as the concentrationincreased, the effect of inhibition raised:5μg/ml group（0.111±0.004、0.112±0.010），1μg/ml group（0.113±0.005、0.140±0.030），0.1μg/ml group（0.114±0.006、0.178±0.010），0.05μg/ml group（0.117±0.004、0.190±0.016），control group（0.154±0.105,0.222±0.003）.(2) Compared with control group (1.132±0.074), the expression of CTGF mRNAin experiment groups are as follows:5μg/ml group（0.556±0.050），1μg/ml group（0.638±0.038），0.1μg/ml group（0.730±0.026），0.05μg/ml group（0.873±0.035）.There is a significant difference between control group and experiment groups (P＜0.05) showing that thymosin beta4can inhibit the expression of CTGF mRNA. (3) The expression of CTGF protein in experiment groups are5μg/ml group（0.510±0.044），1μg/ml group（0.532±0.026），0.1μg/mL group（0.658±0.032），0.05μg/mL group（0.743±0.035）. There are significant differences compared withcontrol group (0.953±0.040)(P＜0.05). As mentioned above in result (2) thymosinbeta4could also significantly inhibit the expression of CTGF protein.Conclusion：Thymosin beta4could inhibit the synthesis of typeⅠ, Ⅲ collagen and theexpression of CTGF in HSFB. It is assumed that thymosin beta4may influence theformation of pathological scar in this way.