Induction of hard keratin expression in non-nail-matrical keratinocytes by nail-matrical fibroblasts through epithelial-mesenchymal interactions.

Abstract

Epithelium in the nail matrix is different from that at other body sites, in terms of clinical and histological appearance. Hard keratins are exclusively expressed in the nail matrix and bed and the hair apparatus, and hard keratin is considered a differentiation marker of these sites. Whether the expression of hard keratin in non-nail-matrical keratinocytes could be induced by nail-matrical fibroblasts was examined. Skin equivalents were constructed in three ways; ventral keratinocytes (from the ventral side of the digit) were cocultured with ventral fibroblasts (group A), ventral keratinocytes were cocultured with nail-matrical fibroblasts (group B), and nail-matrical keratinocytes were cocultured with ventral fibroblasts (group C). Immunohistochemical examinations with anti-hard keratin antibody (HKN-7) revealed hard keratin expression in groups B and C. HKN-7-positive cells were distributed continuously in the entire epithelial strata or in the suprabasal layer in group B, whereas HKN-7-positive cells were distributed spottily in group C. This study indicates extrinsic hard keratin induction in non-nail-matrical keratinocytes by nail-matrical fibroblasts and suggests that non-nail-matrical epidermal grafts may be effective in the treatment of deepithelized nail injuries. In addition, it is possible that lost nails could be reconstructed with grafts of "tissue-engineered" nail equivalent.

• Authors: Mutsumi Okazaki, Kotaro Yoshimura, Hiroshi Fujiwara, Yasutoshi Suzuki, Kiyonori Harii
• Journal: Plastic and reconstructive surgery (Plast Reconstr Surg) Vol. 111 Issue 1 Pg. 286-90 (Jan 2003) ISSN: 0032-1052 [Print] United States
• PMID: 12496590 (Publication Type: Journal Article)

Chemical References

• Antibodies, Monoclonal
• Keratins

Topics

• Antibodies, Monoclonal
• Cell Communication
• Coculture Techniques
• Epithelial Cells (physiology)
• Fibroblasts (physiology)
• Humans
• Immunohistochemistry
• Keratinocytes (metabolism)
• Keratins (biosynthesis)
• Nails (cytology)