Chen Wei, Fu Xiao-bing, Ge Shi-li, Sun Tong-zhu, Jiang Du-yin, Zhou Gang, Sheng Zhi-yong
Key Research Laboratory of Wound Repair, Burns Institute, 304 th Hospital of PLA, Beijing 100037, China.
Zhongguo Wei Zhong Bing Ji Jiu Yi Xue. 2004 Apr;16(4):206-9.
To investigate gene expression of transforming growth factor-beta(1) (TGF-beta(1)) and its two upstream signalling factors (smad2 and smad3) in fetal skin at different gestational ages and postnatal skin and its potential biological significance.
Fetal skin samples of human embryo were obtained from spontaneous abortions at different gestational ages ranging from 13 to 32 weeks, and also skin collected from patients undergoing plastic surgery. After morphological characteristics of skin at different developmental stages were examined histologically, gene expressions of TGF-beta(1), smad2 and smad3 in skin specimens at different developmental stages were examined with reverse transcription-polymerase chain reaction analysis (RT-PCR).
Gene expression of TGF-beta(1), smad2 and smad3 could all be detected in fetal skin and skin after birth. In skin from early gestational fetus, gene expressions of TGF-beta(1) and smad2 were weak. Along with advance in gestational age, gene expression of these two genes in skin became progressively stronger. In skin from late gestational fetus and skin after birth, the transcription contents of these two genes were significantly increased compared with early gestation fetus (P<0.05). On the contrary, gene expression of smad3 was apparently higher in younger fetal skin versus elder compared with that of late fetal skin (P<0.05). In skins after birth, the levels of smad3 gene expression were elevated to the level similar to that in early gestational fetal skin.
The signal pathway mediated by TGF-beta(1) might be involved in regulating development of the skin at embryonic stage and in designating cetaceous structure and function, and also in wound healing after birth. The relative lack in expression of TGF-beta(1) and smad2 genes in skins from younger fetuses might contribute to fetal scar-less healing, in which the role of smad3 needs to be further investigated.
研究不同胎龄胎儿皮肤及出生后皮肤中转化生长因子-β1（TGF-β1）及其两个上游信号因子（smad2和smad3）的基因表达情况及其潜在生物学意义。
从孕13至32周不同胎龄自然流产的人类胚胎获取胎儿皮肤样本，同时收集整形手术患者的皮肤。对不同发育阶段皮肤的形态特征进行组织学检查后，采用逆转录-聚合酶链反应分析（RT-PCR）检测不同发育阶段皮肤标本中TGF-β1、smad2和smad3的基因表达。
TGF-β1、smad2和smad3的基因表达在胎儿皮肤及出生后皮肤中均能检测到。在孕早期胎儿皮肤中，TGF-β1和smad2的基因表达较弱。随着胎龄增加，这两个基因在皮肤中的表达逐渐增强。与孕早期胎儿相比，孕晚期胎儿皮肤及出生后皮肤中这两个基因的转录含量显著增加（P<0.05）。相反，与孕晚期胎儿相比，孕早期胎儿皮肤中smad3的基因表达明显更高（P<0.05）。在出生后的皮肤中，smad3基因表达水平升高至与孕早期胎儿皮肤相似的水平。
由TGF-β1介导的信号通路可能参与调节胚胎期皮肤的发育、指定皮肤结构和功能，以及出生后的伤口愈合。孕早期胎儿皮肤中TGF-β1和smad2基因表达相对缺乏可能有助于胎儿无瘢痕愈合，其中smad3的作用有待进一步研究。
