New data on why hairs thin? A look at the Collagen 17 A1 Protein

Why the Collagen 17 A1 protein could be important for those with hair loss?

A new study published in the prestigious journal Science provides new information into the process of hair thinning.


Collagen 17 A1 (COL17A1)

Researchers from Tokyo showed that stem cells in hair follicles become damaged over time as a process of normal aging. Such damage leads to a reduction in the levels of a protein called collagen 17A1, abbreviated COL17A1. Without this protein, hairs become thinner over time.

The study included important observations in mice and in humans. Researchers studied mice that lacked the COL17A1 gene to try to figure out the precise importance of this protein: The scientists found that without this protein, the mice had hair loss.  When mice were engineered to make extra amounts of COL17A1, they did not have hair loss and hairs did not thin. Turning to human based studies, the researchers analyzed hair samples of women age 22-70. They found that aging leads to a reduction in the levels of Collagen 17 A1 and this reduction seemed to correlate with thinner caliber hairs


Conclusion and Comment

These are interesting observations. At present, it's much too simple to say that adding back collagen 17 A1 to the scalp will promote hair growth.  The Collagen 17 A 1 protein is a complex protein that integrates in the cell membrane of cells and so simply injecting it is unlikely to do much. However, this study reminds us that understanding stem cell aging is likely to yield some of the most important findings to better understand hair loss.



Matsumura H et al. Hair follicle aging is driven by transepidermal elimination of stem cells via COL17A1 proteolysis. Science 05 Feb 2016: Vol. 351, Issue 6273,  


Dr. Jeff Donovan is a Canadian and US board certified dermatologist specializing exclusively in hair loss. To schedule a consultation, please call the Whistler office at 604.283.1887

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