FGF5 is crucial to human length of hair

[IDW2BB]

http://www.ncbi.nlm.nih.gov/pubmed/24989505

Mechanisms that regulate the growth of eyelashes have remained obscure. We ascertained two families from Pakistan who presented with familial trichomegaly, or extreme eyelash growth. Using a combination of whole exome sequencing and homozygosity mapping, we identified distinct pathogenic mutations within fibroblast growth factor 5 (FGF5) that underlie the disorder. Subsequent sequencing of this gene in several additional trichomegaly families identified an additional mutation in FGF5. We further demonstrated that hair fibers from forearms of these patients were significantly longer than hairs from control individuals, with an increased proportion in the growth phase, anagen. Using hair follicle organ cultures, we show that FGF5 induces regression of the human hair follicle. We have identified FGF5 as a crucial regulator of hair growth in humans for the first time, to our knowledge, and uncovered a therapeutic target to selectively regulate eyelash growth.

hair growth or regression without involving androgens? WTH?


Angela Christiano btw.:love:

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2754481/

Although the gene for long hair in mammoths was not here identified, proboscideans remain an important group for understanding the evolution of hair cover. While most mammals have dense hair cover, humans and extant elephants are notable in being relatively hairless [28], and both are closely related to species with much greater hair cover (great apes and woolly mammoths, respectively). Both lineages are also noteworthy in being "genome-enabled" [40] for the study of genes affecting hair cover. The human and chimpanzee genomes have been sequenced [41], while the elephant genome is being sequenced [26], and substantial coverage for the mammoth genome is now available [15]. Other than aquatic species, the number of other mammalian genera considered to be "hairless" is quite small [28]. Thus, for a comparative approach to the evolution of hair cover, proboscideans comprise an important group for further research.

 

[Armando Jose]

eyelashs, eyebrows are special hairs, different from scalp or body hairs and it is posible that tehy don't need androgens ....
BTW interesing issue...

 

[IDW2BB]

http://www.ncbi.nlm.nih.gov/pubmed/14502567

Abstract

Earlier studies demonstrated that knock-out of fibroblast growth factor-5 gene (Fgf-5) prolonged anagen VI phase of hair cycle, resulting long hairs in the mice. We showed the activities on hair growth of the two Fgf-5 gene products, one of which, FGF-5 suppressed hair growth by inhibiting anagen proceeding and inducing the transition from anagen to catagen, and FGF-5S, a shorter polypeptide with FGF-5-antagonizing activity translated from alternatively spliced mRNA, suppressed this activity of FGF-5. As the results suggested that FGF-5 antagonist would increase hair growth, we synthesized various peptides having partial sequences of human FGF-5 and FGF-5S and determined their FGF-5 antagonist activity. Among them, a decapeptide designated P3 (95-VGIGFHLQIY-104) that aligns with receptor binding sites of FGF-1 and FGF-2 suppressed FGF-5-induced proliferation of BALB/3T3 A31 and NIH/3T3 murine fibroblasts, and FGF receptor-1c (FGFR-1c)-transfected Ba/F3 cell line (FR-Ba/F3 cells). IC50s of this peptide on these cell proliferations were 64, 28, 146 microM, respectively. On the other hand, IC50 of this peptide on binding of FGF-5 to the FGFR-1(IIIc)/Fc chimera was 483 microM. Examination in dorsal depilated mice revealed that the P3 peptide reduced the activity of FGF-5 to recover hair pigmentation and hair follicle lengths. The classification of histologically observed skin sections showed FGF-5-induced delations of anagen procedure had reduced by the P3 peptide. The anti-Ki67 antibody staining of hair follicles was inhibited by administration of FGF-5, and this inhibition by FGF-5 was recovered by administration of the P3 peptide. The P3 peptide alone did not affect hair follicle length and hair cell proliferation. These results indicate that the decapeptide antagonized FGF-5 activity in vivo, and reduced the inhibition of FGF-5 in hair growth, confirming that FGF-5 inhibitors are promising substances against hair loss and/or for promoting hair growth.