进行性系统性硬化症皮损中前胶原基因和SMAD mRNA的表达

目的探讨进行性系统性硬化症（PSS）硬化皮肤组织中Ⅰ型和Ⅲ型前胶原基因以及细胞内信号转导分子SMAD mRNA的表达情况,分析它们在发病机制中的作用。方法用荧光实时定量聚合酶链反应法分别检测11例PSS患者硬化皮损及11例正常对照皮肤组织中Ⅰ型和Ⅲ型前胶原基因以及不同类型SMAD（SMAD2、SMAD3、SMAD4、SMAD7）mRNA的表达水平。结果Ⅰ型前胶原基因α1、Ⅲ型前胶原基因α1、SMAD4及SMAD7的mRNA在硬化皮损中的表达明显高于在正常皮肤组织的表达,差异有统计学意义（均P〈0．05）。SMAD4 mRNA的表达与Ⅰ型、Ⅲ型前胶原基因α1 mRNA的表达成正相关（r值分别为0．728和0．678,均P〈0．05）。SMAD3 mRNA的表达与Ⅰ型前胶原基因α1 mRNA的表达成正相关（r=0．859,P〈0．01）。结论PSS硬化皮肤组织中存在有SMAD4 mRNA的高表达,可能是导致Ⅰ型、Ⅲ型胶原在硬化组织中过度堆积的原因之一。

mRNA expression of procollagen and SMADs in lesional skin of progressive systemic sclerosis

OBJECTIVE: To investigate the mRNA expression of type I and type III procollagen and SMADs in the lesional skin of progressive systemic sclerosis (PSS) and analyze the role in pathogenesis of scleroderma thereof. METHODS: Real time PCR was used to detect the mRNA expression of type I and type III procollagen, and SMADs (SMAD 2, SMAD 3, SMAD 4, and SMAD 7) in the lesional skin specimens of 11 patients with PSS and 11 specimens of normal skin. RESULTS: Type I procollagen alpha1, type III procollagen alpha1, SMAD 4, and SMAD 7 were expressed at the mRNA level significantly higher in the lesional skin tissues of the PSS patients than in the normal skin tissues (all P < 0.05). SMAD 4 mRNA expression was positively correlated with type I procollagen alpha1 mRNA expression (r = 0.728, P < 0.05) and the type III procollagen alpha1 mRNA expression (r = 0.678, P < 0.05). SMAD3 mRNA expression was positively correlated with the type I procollagen alpha1 mRNA expression (r = 0.859, P < 0.01). CONCLUSION: Increased SMAD4 mRNA in the lesional skin of systemic sclerosis is positively correlation with increased type I and type III procollagen alpha1 mRNA expression and may be one of the main pathogenesis in resulting in excessive type I and type III collagen accumulation in PSS lesional skin.