瘢痕疙瘩皮损中抑制型SMAD mRNA的低表达

Decreased expression of inhibitory SMADs mRNA in keloid.

用定量Real-time PCR(LightCycler)法分别检测了瘢痕疙瘩,正常瘢痕及正常皮肤组织中不同类型的SMADs(SMAD2、3、4、6、7)mRNA的表达水平.结果显示抑制型SMADs(SMAD6、SMAD7)的mRNA水平在瘢痕疙瘩的组织中明显低于正常瘢痕(P<0.01,P<0.05)及正常皮肤组织(P<0.01,P<0.001).然而,其它类型的SMADs(SMAD2、3、4)mRNA的表达在瘢痕疙瘩,正常瘢痕以及正常皮肤组织中均无明显差异(P>0.05).表明瘢痕疙瘩的皮肤组织中存在有抑制型SMADs(SMAD6、SMAD7)的mRNA水平表达的下调,此结果提示缺乏抑制型SMAD的负反馈抑制在瘢痕疙瘩的发病中可能起着重要的作用.

Expression of three different types of SMADs （SMAD 2, 3, 4, 6, 7） mRNA in skin tissues of keloid, normal scar and normal skin was investigated by real time PCR methods. The results showed that the mRNA expression of inhibitory SMADs （SMAD6, SMAD7） was significantly down regulated in keloid tissue compared with normal scar （P〈0.01 and P〈0. 05 respectively） and normal skin tissues （P 〈0. 01 and P〈0. 001）. However, no significant difference of SMAD2, 3, 4 mRNA expression was found among these tissues （P〉0.05）. It is concluded that there are decreased inhibitory SMADs mRNA expression in keloid, which may explain why TGF-β signalling traducing pathway can not been blocked by auto-negative feedback loop. It suggested that down regulated inhibitory SMADs might play an important part in the pathogenesis of keloid.