血管紧张素II受体在人扩张皮肤中的表达及意义

The expression of angiotensin II receptors in human expanded skin after implantation of skin and soft tissue expander

目的:观察血管紧张素II(AngiotensinII,AngII)1型(AngIItype1,AT1)受体和2型(AngIItype2,AT2)受体蛋白和基因以及血管紧张素原(Angiotensinogen,AGT)基因在人扩张后皮肤和正常皮肤组织中表达的变化。方法:采用常规病理学技术和免疫组织化学方法检测扩张与未扩张皮肤组织的病理特征以及AT1和AT2受体表达的变化,提取扩张与未扩张皮肤组织的总RNA后,用逆转录-多聚酶链式反应法(RT-PCR法)对AGT及AT1和AT2受体在扩张与未扩张皮肤组织中基因的表达变化进行观察。结果:在正常皮肤和扩张后皮肤组织中AT1和AT2受体蛋白和mRNA均有表达。在扩张后皮肤中AT1受体蛋白和mRNA表达显著增加,与正常皮肤组织中的mRNA表达量相比增加约3倍(P<0.05vs正常皮肤);而AT2受体蛋白和mRNA表达仅有轻度增加,且差异并不显著(P>0.05vs正常皮肤)。和AT1受体基因表达的变化趋势类似,AGTmRNA也在扩张后皮肤中表达显著增强,约是正常皮肤的4倍(P<0.05vs正常皮肤)。结论:在皮肤扩张过程中血管紧张素系统被激活,AngII受体AT1表达增加,AngII可能通过AT1受体参与扩张后皮肤组织的病理改变。

Objective The present study was undertaken to observe the change in expression of angiotensin Ⅱ （Ang Ⅱ） type 1 （AT1） and type 2 （AT2） receptors, as well as angiotensinogen （AGT） in both human normal and expanded skin, and explore their potential biological significances. Methods The morphological characteristics of normal and expanded skin were observed histopathologically, and the expression of both AT1 and AT2 receptors in protein levels was detected immunohistochemically. Gene expression of AGT, and both AT1 and AT2 receptors was examined with reverse transcription-polymerase chain reaction （RT-PCR）. Results The gene and protein expression of both AT1 and AT2 receptors was found in normal and expanded skin, gene expression level of AT1 receptor in expanded skin was 3 folds higher than that in normal skin. The expression of AT2 receptor in gene and protein levels was slightly increased in expanded skin. Consistent with the changes of AT1 receptor expression, mRNA expression of AGT was significantly increased in expanded skin when compared with normal skin. Conclusion These observations suggest that renin-angiotensin system is activated in expanded skin, and that Ang Ⅱ via AT1 receptor might be involved in the pathological change of expanded skin. Studying the role of Ang Ⅱ and its receptor-mediated signaling mechanisms associated with this process may be helpful in improving clinical application of skin and soft tissue expander.