A型肉毒毒素通过抑制SMAD3信号通路抑制兔耳瘢痕形成

Botulinum toxin A inhibits rabbit ear scar formation by inhibiting SMAD3 signaling pathway

目的 探讨A型肉毒毒素通过抑制SMAD3信号通路对增生性瘢痕形成的影响。方法 选取12只清洁级新西兰大白兔,将其随机分为对照组与观察组,每组各6只,制作瘢痕模型。建模成功后,观察组于创面9点每点注射2 U浓度为40 U/ml的A型肉毒毒素;对照组于造模后即刻于创面9点每点注射0.05 ml生理盐水。于术后30 d将动物处死取材。HE、Masson染色检测观察组织形态;实时荧光定量PCR检测Ⅰ型胶原(ColⅠ)和α-平滑肌肌动蛋白(α-SMA)的表达;蛋白质免疫印迹实验检测ColⅠ、α-SMA、SMAD3和SMAD3磷酸化的表达情况;免疫组织化学染色检测SMAD3磷酸化表达水平。结果 HE和Masson染色结果显示,经A型肉毒毒素治疗后,组织纤维化程度明显减轻,胶原沉积减少。实时荧光定量PCR检测结果发现,观察组的COLⅠ和α-SMA的mRNA均低于对照组,差异有统计学意义(P<0.05)。蛋白质免疫印迹实验结果发现,A型肉毒毒素能够显著抑制组织中COLⅠ、α-SMA蛋白的表达及SMAD3的磷酸化水平,但是不影响总的SMAD3表达情况。免疫组织化学染色结果显示,A型肉毒毒素能够明显抑制组织中SMAD3的磷酸化水平。结论 A型肉毒毒素可以通过抑制SMAD3信号通路,发挥抑制增生性瘢痕的作用。

Objective To investigate the effect of botulinum toxin type A on hypertrophic scar formation by inhibiting SMAD3 signaling pathway.Methods A total of 12 clean New Zealand white rabbits were selected and randomly divided into control group and observation group,with 6 rabbits in each group,to make scar model.After successful modeling,the observation group was injected 2 U of botulinum toxin A with a concentration of 40 U/ml at each point of the wound.The control group was injected 0.05 ml normal saline at 9 points of the wound immediately after modeling.At 30 days after operation,the animals were sacrificed for HE Masson staining to observe the tissue morphology.The expressions of collagenⅠ(COLⅠ)and alpha-smooth muscle actin(α-SMA)were detected by realtime quantitative PCR.The expression of SMAD3 and SMAD3 phosphorylation by Colα-SMA was detected by western blotting.The phosphorylation level of SMAD3 was detected by immunohistochemical staining.Results HE and Masson staining showed that the degree of tissue fibrosis and collagen deposition were significantly reduced after botulinum toxin type A treatment.Real-time quantitative PCR detection results showed that the mRNA levels of COLⅠandα-SMA in the observation group were lower than those in the control group,and the difference was statistically significant(P<0.05).Western blotting showed that botulinum toxin type A significantly inhibited the expression of COLⅠandα-SMA protein and the phosphorylation of SMAD3,but did not affect the overall expression of SMAD3.Immunohistochemical staining showed that botulinum toxin type A significantly inhibited SMAD3 phosphorylation in tissues.Conclusion Botulinum toxin type A can inhibit hypertrophic scar by inhibiting SMAD3 signaling pathway.