Objective : Dermal papilla is a mesenchyme-derived structure located at the base of the hair follicle and plays an important role in the induction and maintenance of hair growth. Cultured dermal papilla cells sustain hair inductive activity; however, they lose this activity in later passage. In this study, to understand the general features of the dermal papilla cells and screen dermal papilla specific genes, the gene expression profiles were analyzed using cDNA microarray by comparing with closed related dermal fibroblast.
Methods : RNA samples isolated from serial passaged dermal papilla cells and fibroblast were labeled with different fluorescent dyes and hybridized onto hair specific cDNA microarray which contains 4,700 cDNA clones. More than 25 pairs of independent microarray experiments were done and after normalization of scanned images, data were analyzed by Matlab 2007b.
Results : This study showed that gene expression profiles in primary explanted dermal papilla cells before passage were pretty much different from other longer passaged cells. However dermal papilla cells passaged 1 to 4 cells did not show much difference among them. So, the differentially expressed genes were divided into 4 groups; 1) genes commonly over-expressed in dermal papilla cells compared with dermal fibroblast, 2) genes commonly down-regulated in dermal papilla cells compared with dermal fibroblast. 3) genes more predominantly over-expressed in dermal papilla cells before first passage. 4) genes down-regulated in dermal papilla cells before first passage.
Conclusion : the gene expression profiles of cultured dermal papilla cells indicates that they are a kind of myofibroblast-like cells which showed different characters compared with dermal fibroblast. Some genes may be the candidates of dermal papilla specific genes which contributes hair inductive ability of dermal papilla cells. Those genes identified in this study, could be used for useful markers of hair research and treatment of androgenetic alopecia.