Sceptic , thanks for your observation and here is my answer
» I can’t comment about this as I don’t know what a “regenerative mood” is.
I was simply pointing to the case where the body will be ready through its stem cells to make new organs (“Hair follicles” and even “hair follicle stem cells”).
» This is the second time that I see you saying this thing, the first one I
» thought it was an error, do you want acell to produce follicles without the
» sebaceous gland ? do you really know what is the pilosebaceous unit ?
You are right sebaceous glands are always there (this the 1st time I said this though) .However,the shape ,level of activity and the size of those sebacoeus glands is a big question (the ratio = size of the PSU/size of its sebacoeus glands ) . Furthermore, Its know that EGFs affect the proliferation and differentiation of the cells of the PSU …So One might think that we could push toward “the right decision” through EGF manipulation. After all we opened the embryonic window of opportunities/strike for the the sole purpose of simulating what happens when we grow our hair the first time … We gonna be Babies again ! Cheer up
Guys in the thread about that immunity study seem to be right : Once androgens tag the hair follicle its only a matter of time until the Immunity takes it out of business.Of course many argue that the hair follicles gets only miniaturized and are not affected by apoptosis. Stills until now nobody has any clue about how to “UNTAG” a hair follicle so it gets back to its terminal anagen condition. Therefore the “de novo” approach seems ironically more realistic.
Here is a quotation adressing the EGFs effects from "Role of Hormones in Pilosebaceous Unit Development :
"Epithelial and mesenchymal cells appear to communicate during morphogenesis, and these interactions seem to involve molecules or “morphogens” that play a regulatory role in development. Likely morphogens include growth factors, cell adhesion molecules, extracellular matrix molecules, intracellular signaling molecules such as ß-catenin and LEF-1, hormones, cytokines, enzymes and retinoids, together with their receptors (16, 17). Growth factors such as epidermal growth factor (EGF), transforming growth factor (TGF), transforming growth factor ß (TGFß) and fibroblast growth factor (FGF) affect the proliferation and differentiation of the cells of the PSU during development (18). These growth factors appear to exert their effects via autocrine or paracrine pathways between cell types. EGF was the first growth factor to be implicated in hair development when it was shown that its administration to newborn mice delayed hair follicle development (19), and this effect occurred over the entire coat. Furthermore, growth of the first coat of hair in newborn mice is accelerated by the administration of antibodies to EGF (20). The EGF peptide has been found in the outer root sheath and sebaceous gland in later stages of follicular development in sheep skin (21). The EGF receptor has been found in embryonic skin by autoradiography and immunohistochemistry; however, it is present in the adjacent interfollicular epidermis rather than the placode and hair germ (22, 23). In later development, the EGF receptors are expressed in the outer root sheath and sebaceous epithelium, and in some species in the hair bulb, but no EGF receptors have been demonstrated in the dermal papilla (3). The specific distribution of EGF in skin and throughout follicle morphogenesis suggests that this growth factor has a more important role in differentiation than in proliferation (18). TGF, which is in the EGF family and binds to the same receptor as EGF, has also been found to inhibit murine hair growth (24). Several members of the TGFß family (TGFß-1, ß-2, ß-3, bone morphogenetic protein-2, and bone morphogenetic protein-4) have also been localized to various regions of the developing PSU using in situ hybridization (25, 26). FGF was also found to affect hair follicle initiation and development, but the effects were confined to the area of treatment since FGF is not readily diffusible in the skin (18). The FGF receptor 2 is likely to be important in sebaceous gland development in humans, as a somatic activating mutation of this receptor has been associated with localized acne (27). "
Dianne Deplewski and Robert L. Rosenfield"
EGF : epidermal growth factor.
PSU : Pilosebaceous unit.