TLDR The osteopontin gene is active in a specific part of rat hair follicles during a certain hair growth phase and might affect hair cycle and diseases.
The 2001 study found that the osteopontin (OPN) gene is expressed in the dermal papilla of rat pelage follicles specifically during the catagen phase of the hair cycle, but not during the anagen or telogen phases. OPN, an extracellular matrix protein, may play a role in cell attachment, signaling, and tissue survival, and could be involved in the aggregation of dermal papilla cells or protection against apoptosis during catagen. The study also noted that androgen suppresses OPN expression, which could be relevant to hair diseases like androgenic alopecia. The research involved comparing OPN mRNA levels in cultured rat vibrissa dermal papilla cells, which were high, to those in cultured rat skin fibroblasts, where OPN mRNA was not detected. This study enhances the understanding of hair cycle regulation and the potential mechanisms underlying hair disorders.
24 citations,
March 2001 in “Journal of Endocrinology/Journal of endocrinology” Red deer only have androgen receptors in neck hair cells for mane growth during breeding season.
27 citations,
September 1999 in “Journal of Investigative Dermatology” Human skin cells contain Protease Nexin-1, and male hormones can decrease its levels, potentially affecting hair growth.
53 citations,
October 1998 in “The journal of investigative dermatology/Journal of investigative dermatology” Topical calcitriol-analogs can reduce hair loss caused by chemotherapy.
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March 1998 in “Archives of Dermatological Research” The enzyme that changes testosterone to a stronger form is mostly found in the part of the hair follicle called the dermal papilla.
227 citations,
January 1998 in “Journal of Endocrinology” Cells from balding scalps have more androgen receptors than cells from non-balding scalps.
33 citations,
January 1997 in “Endocrinology” Testosterone can slow down hair growth when combined with certain cells from bald scalps, and this effect can be blocked by an androgen receptor blocker.
16 citations,
August 1996 in “The journal of experimental zoology/Journal of experimental zoology” Red deer hair cells offer a new way to study how hormones affect hair growth.
30 citations,
March 1996 in “British Journal of Dermatology”
2 citations,
December 2019 in “FEBS open bio” Combining specific inducers helps dermal papilla cells regain hair-forming ability.
December 2023 in “Animals” The study mapped yak skin cells to understand hair growth better.
2 citations,
February 2024 in “Toxins” Bee venom can help stem cells promote hair growth.
1 citations,
October 2014 in “Skin Pharmacology and Physiology” People with alopecia areata have higher levels of osteopontin, which might be important in the disease's development, but this doesn't relate to how severe the disease is.
5 citations,
August 2011 in “Journal of Dermatological Science” Dentin sialoprotein and phosphophoryn are present in rodent hair follicles and may help hair growth and development.
