O#12   Screening of dermal papilla specific genes using cDNA microarray

Moonkyu Kim, So-Young Cha, Sang-Uk Im, Jung-Chul Kim. Hair Research Center, Kyungpook National University School of Medicine, Korea

Dermal papilla is a mesenchyme-derived structure situated at the base of the hair follicle and plays an essential role in the induction and maintenance of hair growth. As a feasibility test of our homemade hair-specific cDNA chip and to isolate the genes specifically involved in development and cycling of hair, the gene expression profiles were analyzed between cultured dermal papilla (DP) cells and dermal fibroblasts. mRNAs were isolated from four pairs of cultured DP cells and fibroblasts and hybridized onto the cDNA microarray printed 3,063 EST (expressed sequence tags) clones that were isolated from dermal papilla and fibroblast cDNA libraries. Among total 3,063 clones, 41 genes were consistently differentially expressed more than 2-folds as fluorescence intensity in dermal papilla (26 genes) or fibroblast (15 genes). Differentially expressed genes were further compared their relative gene expression levels in cultured dermal papilla cells, dermal sheath cells, and fibroblasts by northern hybridization. Many of the dermal papilla specific genes including, tropomyosin, a-smooth muscle actin, a-acinin, myosin, osteonectin, lumican, and thrombo-spondin, were the genes showing specific characteristics of myofibroblasts. The gene expression profile of cultured dermal papilla cells indicates that dermal papilla cells are a kind of myofibroblast-like cells and they may not only act as hair inducing cells but also as specialize wound healing cells that participate in the homeostasis of tissue extracellular matrix, repair, regeneration and fibrosis.