目的 观察瘢痕疙瘩成纤维细胞(keloid fibroblasts,KFb)转染Smad7过表达载体后,对细胞内Smad7、Ⅰ型胶原、Ⅲ型胶原基因、蛋白表达和细胞增殖的影响,探讨Smad7蛋白对瘢痕疙瘩生长有无抑制作用.方法 收集10例20～25岁男性瘢痕疙瘩患者(排除其他疾病)手术切下的瘢痕疙瘩组织,体外无菌条件下培养KFb后分为3组,A组为未转染组;B组为空载体pcDNA3.1(-)转染细胞组;C组为Smad7基因过表达载体pcDNA3.1(-)-smad7转染细胞组.转染48 h后行实时荧光定量PCR和Western blot法检测各组细胞内Smad7、Ⅰ型胶原、Ⅲ型胶原基因转录和蛋白表达水平,转染24 h后MTT法检测各组细胞增殖能力.结果 C组Smad7mRNA和蛋白相对表达量显著高于A、B组,Ⅰ型胶原、Ⅲ型胶原mRNA和蛋白相对表达量显著低于A、B组,差异均有统计学意义(P＜0.01);B组Ⅰ型胶原和Ⅲ型胶原mRNA相对表达量高于A组(P＜0.01),Smad7、Ⅰ型胶原和Ⅲ型胶原蛋白相对表达量低于A组(P＜0.01).MTT检测示,培养各时间点C组细胞增殖能力均小于A、B组(P＜0.05),A、B组间差异均无统计学意义(P＞0.05).结论 转染Smad7基因过表达载体能抑制KFb Ⅰ型胶原、Ⅲ型胶原基因的表达和细胞增殖能力.“,”Objective To explore if Smad7 protein can inhibit growth of keloids by observing the gene and protein expressions of Smad7,collagen type Ⅰ,and collagen type Ⅲ and cell proliferation after over-expression vectors of Smad7 transfecting keloid fibroblasts (KFb).Methods Fibroblasts were acquired from 10 male patient with keloids at the age of 20 to 25 years.After in vitro culture,KFb were divided into 3 groups:untransfected group (group A),pcDNA3.1 (-) transfected group (group B),and pcDNA3.1 (-)-smad7 transfected group (group C).The mRNA and protein expression levels of Smad7,collagen type Ⅰ,and collagen type Ⅲ were detected by real-time fluorescence quantitative PCR and Western blot at 48 hours after transfection.The cell proliferation ability was detected by MTT assay at 24 hours after transfection.Results The relative expression levels ofmRNA and protein of Smad7 in group C were significantly higher than those in group A and group B (P＜0.01).The relative expression levels of mRNA and protein of collagen type Ⅰ and collagen type Ⅲ in group C were significantly lower than those in group A and group B (P＜0.01).The relative expression levels ofmRNA of collagen type Ⅰ and collagen type Ⅲ in group B were significantly higher than those in group A (P＜0.01);and the relative expression levels of proteins of Smad7,collagen type Ⅰ,and collagen type Ⅲ were significantly lower than those in group A (P＜0.01).The cell proliferation ability in group C was significantly lower than that in group A and group B at each time point by MTT assay (P＜0.05),but no difference was found between group A and group B (P＞0.05).Conclusion Gene expressions of collagen type Ⅰ,and collagen type Ⅲ and cell proliferation will be inhibited after KFb are transfected by over-expression vector of Smad7.