摘要目的 探讨不同浓度A型肉毒毒素(botulinum toxin type A,BTXA)对瘢痕内成纤维细胞中α平滑肌肌动蛋白(α smooth muscle actin,α-SMA)和肌球蛋白-Ⅱ(myosin-Ⅱ)表达水平的影响.方法 从手术切除的挛缩性瘢痕组织中分离培养原代成纤维细胞,选取3～5代成纤维细胞随机分为正常组、低浓度BTXA组(1.0 U/106cells)和高浓度BTXA组(2.5 U/106cells),于药物作用后1、4、7d观察成纤维细胞的生长状况,并采用Wstern blot对成纤维细胞中α-SMA和myosin-Ⅱ的表达进行测定.结果 正常组成纤维细胞生长状态良好;低浓度BTXA组第4天时细胞增殖速度减慢;高浓度BTXA组第4天时细胞部分出现核固缩,第7天时细胞排列较疏松,视野呈现较多凋亡的细胞.α-SMA和myosin-Ⅱ表达在第4天时正常组显著高于BTXA作用组(P＜0.05),第7天时低浓度BTXA组与高浓度BTXA组间比较,差异有统计学意义(P＜0.05).结论 BTXA能够促进成纤维细胞凋亡,减少成纤维细胞中α-SMA和myosin-Ⅱ的表达,且在一定范围内,浓度越高抑制作用越明显.

abstractsObjective To investigate the effects of botulinum toxin type A (BTXA) on the expression of α smooth muscle actin(α-SMA)and myosin-Ⅱ of fibroblasts in scars.Methods Fibroblasts were isolated from tissue specimens of scars contracture.Cells from passages 3-5 were randomly divided into 3 groups (control group,low BTXA group (1 U/106Cells),and high BTXA group (2.5 U/ 106 Cells)).Growth condition of fibroblasts was observed at 1,4,7 day after BTXA treated.Changes of α-SMA and myosin-Ⅱ in fibroblasts were detected by Western blot.Results Fibroblasts grew well in control group.The proliferation was decreased 4 days later in BTXA groups.Lots of apoptotic cells were seen in high BTXA group at 7th day.Proteins of α-SMA and myosin-Ⅱ in fibroblasts were statistically different between BTXA group and control groups at 4th day (P ＜ 0.05).The expression of α-SMA and myosin-Ⅱ in low BTXA group was higher than that in high BTXA group at 7th day(P ＜ 0.05).Conclusions BTXA could induce the apoptosis of fibroblasts and decrease the expression of α-SMA and myosin-Ⅱ in fibroblasts.The inhibitory effect was strengthened with BTXA concentration increase within a certain range.