Talk:Integumentary System - Hair Development

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2011

2010

Cyclic expression of lhx2 regulates hair formation

Törnqvist G, Sandberg A, Hägglund AC, Carlsson L. PLoS Genet. 2010 Apr 8;6(4):e1000904. PMID: 20386748 http://www.ncbi.nlm.nih.gov/pubmed/20386748

Hair is important for thermoregulation, physical protection, sensory activity, seasonal camouflage, and social interactions. Hair is generated in hair follicles (HFs) and, following morphogenesis, HFs undergo cyclic phases of active growth (anagen), regression (catagen), and inactivity (telogen) throughout life. The transcriptional regulation of this process is not well understood. We show that the transcription factor Lhx2 is expressed in cells of the outer root sheath and a subpopulation of matrix cells during both morphogenesis and anagen. As the HFs enter telogen, expression becomes undetectable and reappears prior to initiation of anagen in the secondary hair germ. In contrast to previously published results, we find that Lhx2 is primarily expressed by precursor cells outside of the bulge region where the HF stem cells are located. This developmental, stage- and cell-specific expression suggests that Lhx2 regulates the generation and regeneration of hair. In support of this hypothesis, we show that Lhx2 is required for anagen progression and HF morphogenesis. Moreover, transgenic expression of Lhx2 in postnatal HFs is sufficient to induce anagen. Thus, our results reveal an alternative interpretation of Lhx2 function in HFs compared to previously published results, since Lhx2 is periodically expressed, primarily in precursor cells distinct from those in the bulge region, and is an essential positive regulator of hair formation.

http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.1000904


Characterization of the correlation between ages at entry into breast and pubic hair development

Ann Epidemiol. 2010 May;20(5):405-8.

Christensen KY, Maisonet M, Rubin C, Flanders WD, Drews-Botsch C, Dominguez C, McGeehin MA, Marcus M.

Epidemiology Department, Emory University, Atlanta, GA 30322, USA. klyorita@gmail.com Abstract PURPOSE: The timing of breast and pubic hair development in girls are related, but the degree of correlation has not been well characterized. Periodic observations also are complicated by interval censoring.

METHODS: Data used were from the Avon Longitudinal Study of Parents and Children. Mean age at entry into breast and pubic hair development was determined by the use of parametric survival analysis. The bivariate normal cumulative distribution function was evaluated over the region containing the paired event times; the likelihood was maximized with respect to the correlation coefficient rho.

RESULTS: Among 3938 participants, estimated mean ages at entry into Tanner stage 2 for breast and pubic hair development were 10.19 and 10.95, respectively. The likelihood was maximized at rho = 0.503 to 0.506. This value remained relatively constant among subgroups, although some heterogeneity was observed by maternal and child body mass index and birth order.

CONCLUSIONS: The timing of breast and of pubic hair development is moderately correlated and remain so when it is stratified by characteristics associated with puberty.

PMID: 20382343

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2877869

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(see also Genital System Development)



Original Page References

Reviews

Peters EM, Arck PC, Paus R. Hair growth inhibition by psychoemotional stress: a mouse model for neural mechanisms in hair growth control. Exp Dermatol. 2006 Jan;15(1):1-13.

Sundberg JP, Peters EM, Paus R. Analysis of hair follicles in mutant laboratory mice. J Investig Dermatol Symp Proc. 2005 Dec;10(3):264-70.

Botchkarev VA, Fessing MY. Edar signaling in the control of hair follicle development. J Investig Dermatol Symp Proc. 2005 Dec;10(3):247-51.

Stenn KS, Cotsarelis G. Bioengineering the hair follicle: fringe benefits of stem cell technology. Curr Opin Biotechnol. 2005 Oct;16(5):493-7.

Schmidt-Ullrich R, Paus R. Molecular principles of hair follicle induction and morphogenesis. Bioessays. 2005 Mar;27(3):247-61.

Ahmad W, Panteleyev AA, Christiano AM. The molecular basis of congenital atrichia in humans and mice: mutations in the hairless gene. J Investig Dermatol Symp Proc. 1999 Dec;4(3):240-3.

Ebling FJ. Hair follicles and associated glands as androgen targets. Clin Endocrinol Metab. 1986 May;15(2):319-39.

Articles

Wang Y, Badea T, Nathans J. Order from disorder: Self-organization in mammalian hair patterning. Proc Natl Acad Sci U S A. 2006 Dec 26;103(52):19800-5. Epub 2006 Dec 15. PNAS Link

Ouji Y, Yoshikawa M, Shiroi A, Ishizaka S. Promotion of hair follicle development and trichogenesis by Wnt-10b in cultured embryonic skin and in reconstituted skin. Biochem Biophys Res Commun. 2006 Jun 30;345(2):581-7.

Cui CY, Hashimoto T, Grivennikov SI, Piao Y, Nedospasov SA, Schlessinger D. Ectodysplasin regulates the lymphotoxin-{beta} pathway for hair differentiation. Proc Natl Acad Sci U S A. 2006 May 31

Search NCBI Bookshelf: Bookshelf - hair development

Developmental Biology - Development of the hair follicles in fetal human skin | Eurekah Bioscience Collection - Role of GLI proteins in embryonic hair follicle development | Molecular Biology of the Cell - FGF5 is a negative regulator of hair formatio

Search PubMed: Search May 2006 "hair development" 6,574 reference articles of which 813 were reviews.

Search term = hair development | hair follicle development | lanugo hair