α-平滑肌肌动蛋白N-末端肽对伤口收缩的影响

目的：探讨α－平滑肌肌动蛋白（α－smooth muscle actin, α－SMA）的特异性抗体－α－SMANH2＿末端序列Ac-EED多肽（α－SMA－AcEEED）对伤口收缩的影响。方法L（1）Wistar大鼠背部制作去全厚皮伤口，硬塑料框固定创缘。伤后8－10d，实验 同外用N末端含AcEEED的α－SMA融合(α－SMA-FP,1mg/ml），对照组1、2分别外用胶原凝胶（0.5mg/ml）、N末端含AcDEDE的α－SMA融合蛋白（α－SKA－FP,1mg/ml）。伤后10d，测量各组去掉外固定框1、6、24h时的伤口面积，以取框后伤口面积与伤口原面积的百分比表示伤口收缩率。（2）分离伤后9d肉芽组织中的成纤维，在可变形性硅胶培养皿中培养。观察α－SMA－FP（10μ g/ml）处理成纤维细胞前、后及洗去α－SMA－FP后收缩状态的改变。结果：（1）去除外固定框后1、6、24h时，对照组1、2伤口收缩率相比较差异均无显性意义（P＞0．05）；实验组收缩率与两对照组比较匀有显性意义（P＜0．05）。（2）用α－SMA－FP处理前，镜下可见成纤维细胞有众多粗大皱折。α－SMA－FP处理后5min皱折明显减少，变浅；30min后，皱折完全消失。去除α－SMA－FP后，皱折逐渐恢复。以胶原凝胶和α－SMA－FP处理该细胞无此现象。结论：提示α-SMA-AcEEED在体内可特异性地抑制肉芽组织收缩，在体外能可塑性地抑制成纤维细胞的收缩。

The influence of N-terminal sequence peptide of α-smooth muscle actin on wound contraction

OBJECTIVE: To explore the influence of NH2-terminal sequence Ac-EEED peptide of alpha-smooth muscle actin (alpha-SMA) which is the specific antibody of alpha-SMA on wound contraction. METHODS: (1) Full skin loss wounds were created on the backs of Wistar rats. The wound edge was fixed by a hard plastic frame. The wounds in experimental group (EG) were applied topically with alpha-SMA fusion peptide containing Ac-DEDE at N-terminal (alpha-SMA -FP, 1 mg/ml) during 8 to 10 days after the injury, while gel only (0.5 mg/ml) and alpha-SMA -FP (1 mg/ml) were topically applied to the wounds in control group 1 and 2, respectively. The wound areas were determined at 1, 6 and 24 hours after the removal at the fixing frame at 10 days after injury. The wound contraction rates were determined by comparing the wound area after and before the frame removal. (2) The fibroblasts in the granulation tissue were isolated 9 days after injury and were cultured in deformable silicone substrate dish. The changes in cell contraction were observed before and after the fibroblasts were treated with alpha-SMA -FP (1 mg/ml) and after alpha-SMA -FP was washed away. RESULTS: (1) The wound contraction rates exhibited no evident difference at 1, 6 and 24 hours after the removal of fixing frame in control group 1 and 2 (P < 0.05). (2) There exhibited numerous wrinkles within the fibroblasts under the microscope before alpha-SMA -FP processing. But the wrinkles decreased and became shallow remarkably at 5 mins after alpha-SMA -FP processing and disappeared completely 30 mins later. The wrinkles recovered gradually after alpha-SMA -FP was removed. But the cells treated by gel and alpha-SKA -FP exhibited no such phenomenon. CONCLUSION: alpha-SMA-AcEEED might specifically inhibit the contraction of granulation tissue and inhibit the contraction of fibroblasts, which was reversible.