a case of an interesting previously unreported mixed adnexal tumor of the scalp of a 38 year old man is presented, which was composed of randomly dispersed areas of trichofolliculoma, trichoepithelioma, and pilomatricoma concomitantly. while these lesions are classified under adnexal tumors with differentiation towards hair follicle structures, controversy is present concerning the exact origin...

The mammalian hair follicle unit consists of a central follicle and a series of associated structures: sebaceous glands, arrector pili muscles, Merkel cells, and sensory nerve endings. The architecture of this multicellular structure is highly polarized with respect to the body axes. Previous work has implicated Frizzled6 (Fz6)-mediated planar cell polarity (PCP) signaling in the initial specif...

BACKGROUND The skin is responsible for forming a variety of epidermal structures that differ amongst vertebrates. In each case the specific structure (for example scale, feather or hair) arises from an epidermal placode as a result of epithelial-mesenchymal interactions with the underlying dermal mesenchyme. Expression of members of the Wnt, Hedgehog and bone morphogenetic protein families (Wnt...

Hair follicle is a mini-organ that consists of complex but well-organized structures, which are differentiated from hair follicle progenitor or stem cells. How non-canonical Wnt signaling pathway is involved in regulating hair follicle differentiation remains elusive. Here we showed that Wnt5a regulates hair follicle differentiation through an epithelial-mesenchymal interaction mechanism in mic...

Organ regeneration is becoming a promising choice for many patients; however, many details about the mechanisms underlying organ regeneration remain unknown. As regenerative organs, hair follicles offer a good model to study the mechanisms associated with regenerative medicine. The relevant studies have mainly focused on donor cells, and there are no systematic studies involving the effect of h...

beta-Catenin signaling is required for hair follicle development, but it is unknown whether its activation is sufficient to globally program embryonic epidermis to hair follicle fate. To address this, we mutated endogenous epithelial beta-catenin to a dominant-active form in vivo. Hair follicle placodes were expanded and induced prematurely in activated beta-catenin mutant embryos, but failed t...

Beta-catenin has a dual role in the cell. At the membrane, it connects E-cadherin to the actin cytoskeleton, while in the nucleus, it controls gene expression in concert with Tcf-like transcription factors. Nuclear translocation of beta-catenin is induced by the Wnt signal transduction pathway. Control of this process is essential since elevated beta-catenin levels interfere with differentiatio...

Here, we studied hair follicle development of Liaoning Cashmere goats. Every month for 1 year, skin samples were collected from five 1.5-year-old female goats, and made into paraffin sections. A number of parameters were measured of primary and secondary hair follicles via microscopic observation including follicle depth, hair bulb width, dermis and epidermis thickness, changes in follicle acti...

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...