TLDR Certain immune cells in the skin release a protein that stops hair growth by keeping hair stem cells inactive.
In 2019, researchers discovered that a subset of TREM2+ dermal macrophages, also known as trichophages, secrete Oncostatin M (OSM), a cytokine that inhibits hair growth by keeping hair follicle stem cells (HFSCs) in a resting state. This is achieved through the OSM-OSMRβ-STAT5 signaling pathway. When these macrophages were removed, hair growth and HFSC activation occurred. Genetic deletion of the OSM receptor or STAT5 also led to premature HFSC activation, indicating that the resting stage of hair growth is actively maintained by the hair follicle niche. The study suggests that manipulating this pathway could potentially regulate hair growth.
202 citations,
August 2017 in “Nature cell biology” Lactate production is important for activating hair growth stem cells.
159 citations,
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173 citations,
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40 citations,
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144 citations,
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91 citations,
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73 citations,
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4 citations,
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27 citations,
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59 citations,
March 2020 in “Journal of Biomedical Science” Understanding how hair follicle stem cells work can help find new ways to prevent hair loss and promote hair growth.
April 2024 in “Frontiers in physiology” Immune cells are crucial for hair growth and preventing hair loss.
