Immunohistochemical evaluation of intermediate filament nestin in dog hair follicles

F. Mercati, L. Pascucci, A.M. Gargiulo, C. Dall’Aglio and P. Ceccarelli

Department of Biopathological Sciences and Hygiene of animal and food Productions, Unit of Veterinary Anatomy, Faculty of Veterinary Medicine, Perugia, Italy.

Offprint requests to: Francesca Mercati, Sezione di Anatomia Veterinaria, Dipartimento di Scienze Biopatologiche ed Igiene delle Produzioni Animali ed Alimentari, Facoltà di Medicina Veterinaria, Via S. Costanzo nº 4, 06126 Perugia, Italy. e-mail: fmercati@yahoo.it


Summary. Hair follicles (HFs) are self-renewing structures that reconstitute themselves through the hair cycle. They maintain reservoirs of stem cells (SC) that are thought to reside in the bulge area, a region localized in the lowermost permanent portion of HFs. In mice and humans, HF bulge cells express nestin and present stem features as pluripotency. Nestin is a class VI intermediate filament protein; it was first described as a specific marker of CNS stem cells, but recent studies suggest that it may represent a more general stem cell marker (Wiese et al., 2004; Hoffman, 2006).
Bulge cell characteristics have mainly been studied in mice and humans, but recently, a bulge-like region was identified also in dog HFs (Pascucci et al., 2006). In this work we investigate the presence and localization of nestin in dog HFs with the aim of evaluating its expression and to correlate it with the location of the bulge-like region.
Immunostaining of skin samples collected from healthy dogs was performed by using a rabbit anti-nestin polyclonal antibody. The presence of a population of immunoreactive cells was revealed in the hair follicle middle region, at the arrector pili muscle insertion level. An immunohistochemical signal was detected only in primary hair follicles throughout the hair cycle.
These observations led us to conclude that nestin positive cells are located in the bulge-like region of dog HFs and strengthen our hypothesis regarding the correlation between this region and the dog HF stem compartment. Histol Histopathol 23, 1035-1041 (2008)

Key words: Nestin, Stem cells, Hair follicle, Dog

DOI: 10.14670/HH-23.1035