不同胎龄的胎儿和少儿皮肤中血管形成相关因子基因表达变化的研究

Gene expression of angiogenesis-related factors in fetal skin at diff erent developmental stages and childhood skin

目的 探讨血管内皮细胞生长因子 (VEGF)、血管形成因子 1(Ang 1)、酸性成纤维细胞生长因子 (a FGF)和碱性成纤维细胞生长因子 (b FGF) 4种基因在不同胎龄胎儿和少儿皮肤中表达的变化特征及其可能的生物学意义。方法 采用病理学技术检测不同发育时期皮肤的结构特征后 ,提取 18例不同胎龄(13～ 32周 )的胎儿皮肤和 6例少儿 (4～ 12岁 )皮肤组织的总 RNA后 ,分离 m RNA,用逆转录聚合酶链反应(RT PCR)方法检测这 4种基因在不同组织中的表达变化规律。结果 VEGF、Ang 1、a FGF和 b FGF基因在不同发育阶段的皮肤组织中的表达变化规律不尽相同。在早期妊娠胎儿的皮肤中 ,VEGF和 Ang 1基因表达较强 ,随着胎儿生长发育 ,两种基因表达水平逐渐降低。在妊娠早期的皮肤中 ,a FGF基因表达水平较低 ;而在妊娠中期皮肤内 ,该基因表达水平升至最高 ,随后逐渐降低 ;在少儿皮肤中 ,a FGF基因几乎没有表达。在胎儿皮肤组织中 ,b FGF基因呈强阳性表达 ,转录产物含量较高 ;而在少儿皮肤组织内该基因表达水平显著下降 (P<0 .0 5 )。结论 VEGF、Ang 1、a FGF和 b FGF基因在不同发育时期的皮肤内表达规律不相一致 ,显示这些因子介导的信号通路可能对皮肤的发生、结构功能的维持以及血管的形成十分重要 。

Objective To explore the change in gene expression of angiogenesis-related factors vascular endothe lial growth factor(VEGF), angiopoietin-1(Ang-1), acid fibr oblast growth factor(aFGF) and basic fibroblast growth factor(bFGF), in fetal sk in at different developmental stages and children skin and their potential biolo gical significances. Methods Fetal skin samples of human embryo wer e obtained from spontaneous abortion at different gestational ages ranging from 13 to 32 weeks, and children skin specimens were collected from child patien ts (4~12 years) undergoing plastic surgery. After morphological characteristics of skin at different developmental stages were defined histologically gene exp ressions of VEGF, Ang-1, aFGF and bFGF were examined with reverse t ranscription-polymerase chain reaction analysis (RT-PC R). Results The trend of changes in gene expression of VEGF, Ang-1, aFGF and bFGF was not same for different skin specimens at various developmental stages. In early gestational fetal skin, genes of VEGF and Ang-1 were strongly expressed, while in late gestational and childhood skins , gene expressions of VEGF and Ang-1 were apparently decreased. I n skin of middle gestational stage, the level of aFGF gene expression was highes t, and then it was progressively reduced. In childhood skin, this gene was weakl y expressed. In marked contrast, the contents of transcripts of bFGF showed no s ubstantial change in fetal skin at different developmental stages, whilst the mR NA content of bFGF was significantly decreased in childhood skin. Conclusion VEGF, Ang-1, aFGF and bFGF might be involved in regulating angiogenesis in skin from fetuses of different gestational stages and children. The relative increase in gene transcription of VEGF and -1in younger fetal skin might be one of the reasons why cutaneous cells pr oliferate rapidly and the wounds heal without scar.