Detection of Differentially Expressed Genes in Cultured Epidermal Stem Cells Derived From Children and Adult Skins by cDNA Microarray Technique

Abstract

Epidermal stem cells have the characteristic of the undifferentiated cells in the morphology, and are the biological source of the skin and its subsidiary in the development, repair and reconstruction. The proliferation and differentiation of epidermal stem cell are influenced by many factors, such as integrin, signal transduction pathway and cytokines. Current researches have not yet been able to find absolute recognized epidermal stem cells markers. And on certain characteristics of a single gene expression and its impact studies have made some progress, but the overall characteristics and gene expression changes and developments in the law was unclear. This research detected differentially expressed genes in cultured epidermal stem cells derived from children and adult skins. Samples were derived from 4-12 Y children and 35-55 Y adult skin. The human epidermal stem cells were isolated by trypsin digesting method and purified by collagen adhering method, respectively. Total RNA extracted from epidermal stem cells of two samples. Differentially expressed genes detected by cDNA microarray technique. According to the hybridization results from oligonucleotide DNA microarray, gene expression patterns and functions were analyzed. Adult group compared to children's, there were differentially expressed genes in 1805, which mainly associated with protein translation, energy synthesis and DNA replication, and closely related to the development process of human epidermal stem cells. Down-regulated genes had 716, included GTP binding, sequence-specific DNA binding, MAP kinase phosphatase activity, they related to proliferation and differentiation of epidermal stem cell. Up-regulated genes had 1089, which mainly included cytoskeletal structural protein genes and associated with cell maturation. These data suggest that the gene expression is obviously different between children and adult epidermal stem cell in vitro. This may be closely related to different abilities of proliferation and differentiation of human epidermal stem cell and wound healing ability of skin with different developmental stages. It can provide clues to further search for new markers and the development of regulatory genes, and lay the foundation for further applications.