白细胞介素6/信号转导及转录激活因子3通路及β连环蛋白在机械应力致小鼠增生性瘢痕形成中的作用

Roles of interleukin-6/signal transduction and activator of transcription 3 pathway andβ-catenin in mechanical stress-induced hypertrophic scar formation in mice

目的构建机械应力诱导形成的小鼠增生性瘢痕模型,观察白细胞介素6/信号转导及转录激活因子3(IL-6/STAT3)通路及β连环蛋白在其中的作用。方法采用实验研究方法。取16只12周龄雌性C57/BL6小鼠,分别在其背部制作2个长2 cm的直线全层皮肤切口,伤后4 d,按随机数字表法将每只小鼠背部的2处创面分为机械牵拉组和空白对照组,每组16个创面。机械牵拉组创面给予持续机械牵拉14 d,空白对照组创面不予任何处理。机械牵拉组创面牵拉14 d后,肉眼观察2组创面瘢痕组织的外观并测量瘢痕面积,苏木精-伊红染色观察2组创面瘢痕组织形态学变化并测量瘢痕横截面积,酶联免疫吸附测定法检测2组创面瘢痕组织上清液中IL-6含量,蛋白质印迹法检测2组创面瘢痕组织中磷酸化STAT3(p-STAT3)蛋白的表达,免疫组织化学法检测2组创面瘢痕组织中β连环蛋白的表达。对数据行配对样本t检验。结果机械牵拉组创面牵拉14 d后形成了类似人瘢痕组织的红色无毛区,瘢痕面积较大,局部增厚,质地变硬,部分甚至略隆起,而空白对照组创面瘢痕呈线状,且不明显;机械牵拉组创面瘢痕面积为(5.65±0.95)mm^(2),明显大于空白对照组的(1.07±0.28)mm^(2)(t=26.333,P<0.01)。机械牵拉组创面牵拉14 d后瘢痕组织皮肤附件缺失,真皮层增生活跃、明显增厚,而空白对照组创面瘢痕组织皮肤附件尚存,真皮层增生不明显;机械牵拉组创面瘢痕横截面积为(0.82±0.23)mm^(2),明显大于空白对照组的(0.29±0.07)mm^(2)(t=8.879,P<0.01)。机械牵拉组创面牵拉14 d后瘢痕组织上清液中IL-6含量、瘢痕组织中p-STAT3蛋白表达明显高于空白对照组(t=37.552、25.863,P<0.01)。机械牵拉组创面牵拉14 d后瘢痕组织中β连环蛋白呈高表达,空白对照组创面瘢痕组织中β连环蛋白呈低表达。结论本研究成功构建了机械应力诱导形成的小鼠增生性瘢痕模型。机械应力可通过使小鼠创面IL-6/STAT3通路持续或过度表达参与创面愈合、诱导瘢痕增生,β连环蛋白也有促进增生性瘢痕形成的作用。

Objective To establish mechanical stress-induced hypertrophic scar mouse models,and to examine the roles of interleukin-6/signal transduction and activator of transcription 3(IL-6/STAT3)pathway andβ-catenin.Methods The experimental research method was used.Sixteen female C57/BL6 mice of 12-week-old were collected and two straight full-thickness skin incisions of 2 cm in length were inflicted on the back of each mouse.On the fourth day post injury,the two wounds on the back of each mouse were divided into mechanical traction group and blank control group according to the random number table method,with 16 wounds in each group.The wounds in mechanical traction group were given continuous mechanical traction for 14 days,while the wounds in blank control group were given no treatment.After 14 days of mechanical traction for wounds in mechanical traction group,the appearances of the scar tissue in wounds of 2 groups were visually observed,and the areas of scars were measured;the morphological changes of the scar tissue in wounds of 2 groups were observed by hematoxylin-eosin staining,and the cross-sectional areas of scars were measured;the content of IL-6 in supernatant of the scar tissue in wounds of 2 groups was detected by enzyme-linked immunosorbent assay;the protein expression of phosphorylated STAT3(p-STAT3)of the scar tissue in wounds of 2 groups was detected by Western blotting;and the expression ofβ-catenin of the scar tissue in wounds of 2 groups was detected by immunohistochemistry.Data were statistically analyzed with paired sample t test.Results Red hairless area similar to human scar tissue formed in wounds of mechanical traction group after 14 days of mechanical traction,with large area of scar,thickened local area,hardened texture,and some even slightly raised,while scar in wounds of blank control group was linear and not obvious.After 14 days of mechanical traction for wounds in mechanical traction group,the scar area of wounds in mechanical traction group was(5.65±0.95)mm^(2),which was significantly larger than(1.07±0.28)mm^(2)in blank control group(t=26.333,P<0.01).After 14 days of mechanical traction for wounds in mechanical traction group,the skin appendages of scar tissue were absent,and the dermis hyperplasia was active and obviously thickened,while skin appendages of scar tissue of wounds in blank control group were still present,with unconspicuous dermis hyperplasia;the cross-sectional area of scar in wounds of mechanical traction group was(0.82±0.23)mm^(2),which was significantly larger than(0.29±0.07)mm^(2)of blank control group(t=8.879,P<0.01).After 14 days of mechanical traction for wounds in mechanical traction group,the content of IL-6 in the supernatant of scar tissue and the protein expression of p-STAT3 in scar tissue of wounds in mechanical traction group were significantly higher than those in blank control group(t=37.552,25.863,P<0.01).The expression ofβ-catenin was high in the scar tissue of wounds in mechanical traction group after 14 days of mechanical traction,while that in blank control group was low.Conclusions The study successfully establishes mechanical stress-induced hypertrophic scar mouse models.Mechanical stress can participate in wound healing and induce scar hyperplasia of mice wounds through continuous or overexpression of IL-6/STAT3 pathway,andβ-catenin can also promote the formation of hypertrophic scar.