TLDR Normal skin cell renewal doesn't need RAR signaling, but vitamin A-related skin thickening does.
The 2002 study explored how retinoic acid (RA) and its receptors (RARs) affect the proliferation of basal keratinocytes in the epidermis. It was discovered that the normal renewal of keratinocytes does not require RAR-mediated signaling, as evidenced by the maintenance of proliferation in mice lacking RARα, RARβ, and RARγ. However, RA-induced epidermal hyperplasia was found to depend on RXR/RARγ heterodimers, with RXRα/RARγ being necessary for this process, while RXRα/RARα heterodimers were not. The study also indicated that RARγ plays a crucial role in the suprabasal layers for RA-induced hyperplasia, and there is some functional redundancy among the RARs and RXRs. The specific number of mice used in the study was not mentioned in the summary.
232 citations,
January 2002 in “Mechanisms of development” Different enzymes are active in different parts of developing mouse organs.
111 citations,
April 2000 in “British journal of dermatology/British journal of dermatology, Supplement” Thyroid hormone receptor β1 is found in human hair follicles and helps them survive.
April 2024 in “JEADV. Journal of the European Academy of Dermatology and Venereology/Journal of the European Academy of Dermatology and Venereology” Retinoic acid helps activate hair growth in people with common hair loss by working on a specific cell growth pathway.
91 citations,
February 2009 in “Journal of biological chemistry/The Journal of biological chemistry” DGAT1 enzyme is crucial for healthy skin and hair by regulating retinoid levels.
6 citations,
September 2012 in “Our Dermatology Online” Retinoids are effective for various skin conditions and hair loss but have serious side effects, so low doses are recommended.
16 citations,
October 2023 in “Molecular cancer” New treatments like nanotechnology show promise in improving skin cancer therapy.
16 citations,
September 2019 in “Journal of biological chemistry/The Journal of biological chemistry” Mice without certain skin enzymes have faster hair growth and bigger eye glands.
