30 citations,
July 2010 in “Experimental Dermatology” Polyamines are important for hair growth, but more research is needed to understand their functions and treatment potential.
21 citations,
June 2009 in “Mammalian genome” A new mutation in the Hr gene causes hair loss in mice, similar to a human hair disorder.
107 citations,
September 2002 in “Journal of Investigative Dermatology” Researchers found that hair shedding happens mostly when new hair is growing and involves a unique process.
54 citations,
May 2001 in “Journal of Investigative Dermatology” 20 citations,
April 2000 in “Experimental dermatology” ODC transgenic mice can model human hair loss with skin lesions.
24 citations,
June 1999 in “Mechanisms of Development” The study demonstrated that ornithine decarboxylase (ODC) played a significant role in hair follicle development and hair growth by being associated with cell proliferation and commitment. ODC was expressed in embryonic epidermis at sites of follicle development and persisted in proliferating bulb cells of anagen follicles, except at the base of the bulb. Its expression decreased as follicles entered catagen and resumed with new follicle initiation. In vibrissae, ODC showed a complex expression pattern, being present in both the bulb and hair shaft, and in outer root sheath cells near the follicle bulge, suggesting a link to hair follicle stem cells.
124 citations,
July 1997 in “Journal of Biological Chemistry” In this study, researchers created a transgenic mouse line that overexpressed spermidine/spermine N^1-acetyltransferase, leading to significant alterations in tissue polyamine pools. These changes included the presence of N^1-acetylspermidine, an unusual accumulation of putrescine, and reduced levels of spermidine and spermine. The most notable phenotypic effect was permanent hair loss in mice aged 3 to 4 weeks, associated with the formation of follicular cysts in the dermis, likely due to putrescine's interference with hair follicle cell differentiation and proliferation. Additionally, female mice were infertile, linked to ovarian hypofunction and underdeveloped uteri. This research highlighted the potential of using spermidine/spermine N^1-acetyltransferase overexpression to manipulate polyamine levels in transgenic animals for studying developmental and cancer-related outcomes.
233 citations,
July 1997 in “PubMed” In this study, researchers investigated whether overexpression of ornithine decarboxylase (ODC) was sufficient for tumor promotion in mouse skin. They used transgenic mice with high ODC expression in epidermal keratinocytes and found that these mice were more sensitive to carcinogen initiation compared to controls. Notably, mice with ODC overexpression in hair follicle keratinocytes developed tumors without the need for additional tumor promoters. The study concluded that ODC overexpression was sufficient to activate target cells in hair follicles, leading to clonal expansion and epidermal tumor formation, indicating that hair follicles are key sites for chemical carcinogen targeting in the skin.
71 citations,
May 1996 in “Journal of Investigative Dermatology” The study investigated the role of ornithine decarboxylase (ODC) in hair follicle function using transgenic mice that overexpressed a mutated ODC transgene in hair follicle keratinocytes. These mice experienced normal initial hair growth but lost their hair completely 2-3 weeks after birth, coinciding with the onset of ODC overexpression and the development of follicular cysts. The study found that the ODC inhibitor 2-difluoromethylornithine could prevent hair loss and partially restore normal skin histology if administered early, and it could also reactivate hair growth in mice with complete hair loss. The results suggested that ODC played a crucial regulatory role in mouse hair follicles.
35 citations,
November 1931 in “Journal of Genetics” Hairless mice lack fur due to a genetic mutation affecting skin response, not hormone issues.
