Quantitative analysis of the proliferation of epidermal cells using a human skin organ culture system and the effect of DbcAMP using markers of proliferation (BrdU, Ki-67, PCNA)

The process of re-epithelialization of a wound in the epidermis comprises t he following steps: proliferation of epidermal basal cells, migration of ep idermal cells to the wound surface, and cell differentiation. In the presen t study, we evaluated the proliferation of epidermal basal cells, an import ant process in wound healing, in the wound margin using a human skin organ culture system and immunohistochemical labeling with bromodeoxyuridine (Brd U), Ki-67, and proliferating cell nuclear antigen (PCNA), as markers of cel l proliferation. Dibutyryl cyclic adenosine monophosphate (DbcAMP) is a der ivative of cAMP and has been shown to modulate human keratinocyte prolifera tion, The proliferation of keratinocytes was promoted by DbcAMP and particu larly strong effects in terms of BrdU labeling index, Ki-67-positive ratio, and PCNA-positive ratio, were seen at 10(-5) M, The skin organ culture sys tem presented here uses adult preputial skin and is a simple technique that uses easily available materials. In addition to identifying S phase cells using BrdU as an index of cell proliferation, the immunohistochemical metho d for evaluating the expression of Ki-67 and PCNA is very simple. According ly, the method described here seems to be useful for evaluating cell dynami cs in wound healing.