Bcl-2 Expression in the Developing Hair Follicle of Korean Fetal Scalp / 대한해부학회지

ABSTRACT

This study was intended to understand the role of the apoptosis-suppressing gene, bcl-2, in the hair follicle development. Immunohistochemistry for bcl-2 was performed using a high-throughput tissue-array technique, on Korean fetal scalp tissues at the 14 weeks, 16 weeks, 19 weeks & 24 weeks of the development. The results showed that the basal cells of epidermis were stained from 14 weeks to 24 weeks and the immunoreactive melanocytes were observed in the basal layer and suprabasal layer of epidermis as well as in the hair matrix cells and the external root sheath. At 19 weeks, the follicles at all stages of morphogenesis were observed. In the early stages, the epithelial cells of hair germ and hair peg, the mesenchymal cells surrounding them were stained. In the more advanced stage, the bcl-2 expression of follicular epithelial cells diminished to allow keratinization, hair canal formation and holocrine secretion to take place. In the bulbous hair peg stage, the hair papilla cells, the hair matrix cells, the basal cells of the primitive sebaceous gland, the primitive arrector pilli and the basal cells of the external root sheath were stained. We confirmed in the developing hair follicle that in the early stage or in the place where the cells continued to proliferate, the immature cells expressed bcl-2 to suppress cell death to overcome the susceptibility to cell death and when the differentiation was being achieved, the reduction of bcl-2 expression increased cell death to perform the tissue morphogenesis or the organ functions