terized by ectodermal dysplasia (ED). The nectin-1 (N1) null mutant mice have a mild defect in skin, (Wakamatsu etal., 2007), but no severe phenotypes were reported, suggesting the compensation by other nectins. In this study, we tested this hypothesis by generating N1 and N3 compound mutant mice. We observed coexpression of N1 and N3 in the inner root sheath of hair follicles and in the suprab...

The Sonic hedgehog (Shh) signaling pathway regulates developmental, homeostatic, and repair processes throughout the body. In the skin, touch domes develop in tandem with primary hair follicles and contain sensory Merkel cells. The developmental signaling requirements for touch dome specification are largely unknown. We found dermal Wnt signaling and subsequent epidermal Eda/Edar signaling prom...

Intricate coordinated mechanisms that govern the synchrony of hair growth and melanin synthesis remain largely unclear. These two events can be uncoupled in prematurely gray hair, probably due to oxidative insults that lead to the death of oxidative stress-sensitive melanocytes. In this study, we examined the gene expression profiles of middle (bulge) and lower (hair bulb) segments that had bee...

Little is known about the function of desmosomes in the normal structure and function of hair. Therefore, it was surprising that mice without desmoglein 3 (the autoantigen in pemphigus vulgaris) not only developed mucous membrane and skin lesions like pemphigus patients, but also developed hair loss. Analysis of this phenotype indicated that hair was normal through the first growth phase ('foll...

terized by ectodermal dysplasia (ED). The nectin-1 (N1) null mutant mice have a mild defect in skin, (Wakamatsu etal., 2007), but no severe phenotypes were reported, suggesting the compensation by other nectins. In this study, we tested this hypothesis by generating N1 and N3 compound mutant mice. We observed coexpression of N1 and N3 in the inner root sheath of hair follicles and in the suprab...

BACKGROUND CD1d belongs to a family of antigen presenting molecules that are structurally and distantly related to the classic major histocompatibility complex class I (MHC I) proteins. However, unlike MHC I molecules, which bind protein antigens, CD1d binds to lipid and glycolipid antigens. CD1d is expressed by cells of lymphoid and myeloid origin, and by cells outside of the lymphoid and myel...

Hair follicles display periodic growth. Wnt signaling is a critical regulator for hair follicle regeneration. Previously, we reported that Wnt5a inhibits the telogen-to-anagen transition of hair follicles, but the mechanism by which this process occurs has not yet been reported. Here, we determined the expression patterns of Wnt signaling pathway molecules by quantitative reverse transcription ...

Alopecia can be either scarring or non-scarring. Non-scarring alopecias tend to have preserved follicular ostia, with no clinically visible inflammation in most presentations, although histologic inflammation may be present. The common types of non-scarring alopecias are androgenic alopecia, telogen effluvium, alopecia areata, trichotillomania and traction alopecia. Scarring alopecias, also kno...

BACKGROUND Hair follicles are known to contain a well-characterized niche for adult stem cells: the bulge, which contains epithelial and melanocytic stem cells. Stem cells in the hair bulge, a clearly demarcated structure within the lower permanent portion of hair follicles, can generate the interfollicular epidermis, hair follicle structures, and sebaceous glands. The bulge epithelial stem cel...

The autologous transplantation of hair follicles that have been separated into single follicular units is an accepted treatment for androgenetic alopecia. Recent studies demonstrate that the multiple stem cell populations and surrounding cutaneous tissues coordinately regulate the hair follicle functions and skin homeostasis. Therefore, the critical issues for consideration regarding functional...