When a child gets a scrape from falling off her bike, special cells in her skin rush to help by growing new skin to cover the wound. Usually, the purpose of only a portion of these cells is to repair the skin. Hair growth is typically the result of external factors. However, they can temporarily alter their function in situations like this to aid skin healing.
New research from the Rockefeller University indicates that once these cells become this flexible, they cannot function normally until they determine whether to differentiate into skin or hair cells. Unexpectedly, vitamin A—present in foods like carrots—plays a significant part in this procedure. This finding might be beneficial.
Rockefeller’s Elaine Fuchs said, “Our goal was to understand this state well enough to learn how to dial it up or down. We now better understand skin and hair disorders and a path toward preventing lineage plasticity from contributing to tumor growth.”
When cells in the body alter their regular function, this is known as lineage plasticity. It is observed in both cancer and wound healing. Since the skin is often injured, minor injuries are ideal for investigating this. Hair follicle stem cells are specialized cells that proliferate in response to damage to the epidermis.
Researchers like Fuchs and her team are studying lineage plasticity closely. They think it’s important because it helps the body heal, but too much of it might lead to problems like chronic healing or cancer.
In the lab, Fuchs and her colleagues experimented with various chemicals on mouse stem cells to gain further insight into how the body regulates this process. They discovered that retinoic acid, a vitamin A, is beneficial.
Researchers discovered that changing the levels of retinoic acid, a type of vitamin A affected how stem cells reacted to skin injuries and regrew hair in mice. This interaction between retinoids and molecules like BMP and WNT determined whether the stem cells stayed quiet or got busy regrowing hair.
The group also discovered that the proper ratio of retinoic acid is essential for hair follicle stem cells to aid in wound healing. Overly high levels prevent them from switching jobs appropriately. In contrast, low levels cause them to concentrate too much on mending and need more on hair growth.
It’s been hard to understand how retinol (a form of vitamin A) affects the body for a long time. In rare cases, applying retinoid creams to wounds might promote hair growth; nevertheless, overuse of retinoids can cause hair loss. In terms of skin healing, retinoid effects are likewise conflicting. According to this recent study, retinoids are essential regulators of skin and hair cells.
Retinoids’ effects on cancer cells, particularly those of the skin, such as squamous and basal cell carcinoma, are the research subject in the Fuchs lab. According to Fuchs, unbridled lineage plasticity appears to exacerbate cancer by causing cancer stem cells to behave abnormally in every case.
Basal cell carcinomas have less lineage plasticity and are less aggressive than squamous ones. If future research shows that stopping lineage plasticity can help control tumor growth and improve outcomes, retinoids might become an essential part of cancer treatment.
Vitamin A, especially retinoids, is essential for how stem cells work and heal wounds. This shows that we need to keep studying this area. By figuring out how retinoids and stem cells interact, researchers hope to find new ways to treat skin problems and learn more about how cancer grows and how wounds heal.
Journal reference:
- MATTHEW T. TIERNEY, LISA POLAK et al., Vitamin A resolves lineage plasticity to orchestrate stem cell lineage choices. Science. DOI: 10.1126/science.adi7342.