Effects Of Hydroxycamptothecin On Collagen Synthesis And Smad7 Expression Of Human Hypertrophic Scar Fibroblasts

Goal: Hypertrophic scar (HS) is severely affected people,s appearance and function, but prevention and treatment of HS is still a difficult problem in the area of burn and plastic surgery medical research. In order to understand the mechanism of HCPT on treat scar, this study observed the effects of 10-hydroxycamptothecin (HCPT) on fibroblast collagen synthesis and the expression of cell signal transduction inhibitor Smad7,Methods: HS obtained from patients who received plastic surgery, and then hypertrophic scar fibroblasts (HSFB) were cultured in vitro using tissue culture method. (1) HSFB was intervened by HCPT with various concentrations (63,125,250,500,1000ng/ml), the secretion of typeⅠ,Ⅲcollagen from HSFB were assayed with ELISA method after 24,48,72 hours. (2) HSFB was intervened by HCPT with various concentrations (125,250,500ng/ml) for 24 hours, then the expression of Smad7 mRNA was measured with RT-PCR and Smad7 protein was detected with western blot method.Results : (1) Compared with the control group, HCPT with various concentrations (63,125,250,500,1000ng/ml) can inhibit the secreation of typeⅠ,Ⅲcollagen, and as the concentration increased, the effect of inhibition raised. But there is no significant relation with action time. (2) Compared with control group (0.215±0.020), the expression of Smad7mRNA in experiment groups is 0.350±0.037,0.431±0.054,0.616±0.038. There is significant difference between control group and experiment group (P<0.05). the expression of Smad7 protein in experiment groups is 0.431±0.027,0.540±0.043,1.186±0.148. And there is significant difference compared with control group (0.280±0.033). (P<0.05). These is indicated that hydroxycamptothecin could significantly increase Smad7 protein and mRNA expression in human hypertrophic scar fibroblasts,especially when its concentration at 500ng/mL.Conclusion:Hydroxycamptothecin could inhibit collagen synthesis of HSFB, and enhanced the expression of Smad7 mRNA and protein, ,which has a role in the treatment of hypertrophic scars.