TLDR Telogen is an active phase with important biological processes, not a resting phase.
The study identified 425 differentially expressed genes in telogen phase hair follicles, revealing that telogen is a highly dynamic phase rather than a quiescent one. These genes fell into three major clusters, with significant functions in proteolysis, rhythmic processes, cholesterol metabolism, and actinomyosin structure organization. Notably, genes like adipocyte enhancer binding protein 1 (Aebp1) and Keratin 24 showed significant upregulation in telogen, suggesting new regulatory roles. The findings challenged the traditional view of telogen as a resting phase, highlighting its active biological processes and regulatory significance in hair follicle cycling.
499 citations,
September 2011 in “Cell” Fat-related cells are important for initiating hair growth.
176 citations,
April 2011 in “Science” Hair stem cell regeneration is controlled by signals that can explain different hair growth patterns and baldness.
81 citations,
April 2009 in “Journal of Investigative Dermatology” Hair shedding is an active process that could be targeted to treat hair loss.
21 citations,
May 2022 in “Frontiers in Cell and Developmental Biology” Hair growth and health are influenced by factors like age, environment, and nutrition, and are controlled by various molecular pathways. Red light can promote hair growth, and understanding these processes can help treat hair-related diseases.
21 citations,
May 2016 in “Experimental and Therapeutic Medicine” The study investigated the expression of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) during the hair cycle in mice. It found that MMP-2 and MMP-9 had elevated mRNA and protein expression levels during the anagen phase and decreased levels during the catagen and telogen phases. Their activities fluctuated throughout the hair cycle. TIMP-1 and TIMP-2 expression levels were negatively correlated with MMP-9 and MMP-2, respectively. Immunohistochemical analysis showed that MMP-2 and TIMP-2 were present in all hair follicle structures, while MMP-9 and TIMP-1 were localized to specific areas. These findings suggested that MMP-2 and MMP-9 played significant roles in the hair growth cycle.
April 2016 in “Journal of Investigative Dermatology” Wnt ligands, produced by dermal papilla cells, are essential for adult hair growth and regeneration.
