Cosmetic Surgery Research Today is a free monthly online journal that collates and summarizes the latest research about Cosmetic Surgery, including details on microsurgery, reconstruction, techniques, risks.

Human scalp skin and hair follicles express neurotrophin-3 and its high-affinity receptor tyrosine kinase C, and show hair cycle-dependent alterations in expression.

Adly MA, Assaf HA, Nada EA, Soliman M, Hussein M

Department of Zoology, Sohag Faculty of Science, South Valley University, Sohag, Egypt.

BACKGROUND: Neurotrophin (NT)-3 and its high-affinity receptor tyrosine kinase C (Trk C) are essential for nervous system development. These members of the NT family are also involved in murine hair morphogenesis and cycling. However, their role in human hair follicle (HF) biology remains to be elucidated. OBJECTIVES: To explore the role of NTs in human skin and HF biology. METHODS: The immunoreactivity (IR) of NT-3 and Trk C was studied in human scalp skin and HFs by immunofluorescent and light microscopic immunohistology. Skin biopsies were obtained from normal human scalp containing mainly anagen VI HFs from women (age 53-57 years) undergoing elective plastic surgery. RESULTS: Both NT-3 and Trk C showed prominent, yet distinct, IR patterns in human scalp anagen HFs (anagen VI), whereas they were weakly expressed in catagen and increased again in telogen HFs. Within HF compartments, NT-3 IR was prominent in the outer root sheath, inner root sheath, dermal papilla and connective tissue sheath. Trk C IR was prominent in all HF epithelial and mesenchymal compartments. Outside the HF, both NT-3 and Trk C showed prominent IR in the epidermis, sebaceous glands and sweat glands. CONCLUSIONS: These observations provide the first indication that NT-3 and Trk C are expressed in human scalp skin and HFs, and suggest that Trk C-mediated signalling is involved not only in murine but also in human HF biology. They may be useful in determining therapeutic strategies for the treatment of hair cycle and skin-related disorders.

Published 25 August 2005 in Br J Dermatol, 153(3): 514-20.
Full-text of this article is available online (may require subscription).

© 2005-2008 Cosmetic Surgery Research Today. All Rights Reserved.