不同发育阶段胎儿表皮干细胞差异表达基因的研究

目的采用基因芯片技术筛选早期胎儿与晚期胎儿表皮干细胞差异表达基因,分析不同发育阶段胎儿表皮干细胞基因表达变化特征及其可能的生物学意义,为进一步寻找表皮干细胞特异性发育调控基因提供新线索。方法收集胎龄8～12周人胎儿正常皮肤(早期胎儿组)及28～32周人胎儿正常皮肤(晚期胎儿组),采用胰蛋白酶和EDTA联合消化法分离表皮,Ⅳ型胶原快速黏附法分离、纯化人表皮干细胞,分别提取各组细胞总RNA,用基因芯片技术检测2组胎儿表皮干细胞基因表达并筛选差异表达基因。结果基因芯片高通量地揭示了早期胎儿组与晚期胎儿组表皮干细胞的遗传信息。晚期胎儿组与早期胎儿组相比,DNA复制均与表皮干细胞的发育进程密切相关。差异表达基因有805个,其中表达下调的基因有389个,主要是GTP结合蛋白基因、序列特异性DNA结合蛋白基因、MAKP活性蛋白基因等与细胞增殖分化相关基因;表达上调的基因有416个,主要是与细胞成熟相关的细胞骨架结构蛋白基因等。结论体外培养的早期胎儿与晚期胎儿表皮干细胞基因表达谱有明显的不同,其差异可能与不同发育阶段人表皮干细胞的增殖分化能力及皮肤创伤修复能力不同密切相关。

Differentially Expressed Genes in Epidermal Stem Cells from Fetuses at Different Developmental Stages

Objective To identify the differentially expressed genes by cDNA microarray analysis in epidermal stem cells from fetuses at early and late stages of pregnancy and the possible biological significance, and to provide new clues for further exploring the genes regulating epidermal stem cell- specific development. Methods Normal skin samples were collected from 8-12 week fetuses （early fetal group） and 28-32 week fetuses （late fetal group）. The epidermis was separated using trypsin- EDTA digestion. Epidermal stem cells were separated and purified by the attachment to type IV collagen. Total RNA was extracted from epidermal stem cells and differentially expressed genes in epidermal stem ceils from fetuses at early and late stages of pregnancy were detected by cDNA microarray analysis.Results High-throughput screening of microarrays reveled the genetic information in fetal epidermal stem cells. A total of 805 genes were differentially expressed in epidermal stem ceils between early fetal group and late fetal group. These differentially expressed genes were involved in protein translation, energy synthesis and DNA replication, and were closely related to the development process of human epidermal stem ceils. Of the 805 genes, expression was down-regulated in 389,including GTP-binding protein gene, sequence-specific DNA binding protein gene, MAP kinase phosphatase protein gene, and other cell proliferation and differentiation-associated genes. Expression was up-regulated in 416 genes, and most of them were cell maturation-associated cytoskeletal structural protein genes. Con~lusiort The gene expression is obviously different in epidermal stem cells between fetuses at early stages of pregnancy and fetuses at late stages of pregnancy. The difference may be closely related to different abilities of epidermal stem cell proliferation and differentiation and skin wound healing in fetuses at different developmental sta~a~