Seoul National University Hospital Identifies Clues for Hair Loss and Scar-Free Regeneration in Fetal Skin

Identification of Arrector Pili Muscle Progenitor Cells:
Key Mechanisms for Hair Regeneration Revealed
Possible Turning Point in Human Skin Regenerative Capacity Around 17 Weeks of Gestation

A team of Korean researchers has conducted a detailed analysis of fetal skin development, uncovering clues for hair loss treatment and scar-free skin regeneration.

From the left: Osang Kwon, Professor of Dermatology at Seoul National University Hospital; Hanjae Lee, Clinical Instructor; and Jongil Kim, Professor of Biochemistry at Seoul National University College of Medicine. Seoul National University Hospital

On May 15, Seoul National University Hospital announced that a joint research team led by Osang Kwon, Professor of Dermatology at Seoul National University Hospital, and Jongil Kim, Professor of Biochemistry at Seoul National University College of Medicine, constructed a skin development map through multi-omics analysis and identified potential progenitor cells of the arrector pili muscle—a key target for hair loss treatment. The results have been published in the latest online edition of the international journal Experimental & Molecular Medicine.

The arrector pili muscle is a tissue attached to the hair follicle that is involved in the activation of hair follicle stem cells. It is known to be associated with the potential for hair regeneration in patients experiencing hair loss. However, it had not been clearly established from which cells this muscle originates and how it is formed.

The research team performed an integrated single-cell level analysis of the transcriptome and chromatin accessibility in mouse skin cells from the fetal stage until immediately after birth. As a result, they identified that upper fibroblasts in the upper layer of the skin are candidate progenitor cells of the arrector pili muscle. In this process, they also proposed a pathway in which the gene Mef2c is activated first, followed by the activation of Myocd, which then induces differentiation of the arrector pili muscle.

The researchers conducted a comparative analysis with human fetal skin data and found interspecies similarities in stages of skin development. They discovered that the stage of skin development in newborn mice is similar to that of a human fetus around the 17th week of gestation.

In a previous study, the research team had confirmed that mouse skin loses its ability for scar-free regeneration from the point when it starts to differentiate into specific tissues. Based on the results of this comparative analysis, they suggested that in humans, the period around the 17th week of gestation may be the turning point for changes in skin regenerative capacity.

The researchers explained that while these findings do not immediately translate into treatment development, they can serve as foundational data for regenerative medicine research aimed at treating hair loss and scarring. Professor Kwon, who led the study, stated, "It is highly significant that we have identified the origin of the arrector pili muscle—a central element in hair loss treatment—through multi-omics analysis, and demonstrated that the trajectories of skin development in mice and humans are consistent. The 'skin development map' established in this study will provide a basis for directly applying regenerative medicine to humans in the future, including full hair follicle regeneration and scar-free wound healing."

This content was produced with the assistance of AI translation services.