Today's hair loss
news brings with it, not only the potential for future treatments to preventing thinning hair caused by ageing, but also some top pub quiz trivia.
Did you know that humans have a signalling pathway known as the Sonic hedgehog gene? The thorny-looking protein was named after the spiky blue cartoon character when he was a comic star, before becoming an icon of modern pop culture via the world of video gaming. Scientists even suggested changing the protein's name to something with more gravitas once the speedy ring-collector become such a global phenomenon.
After on-going investigations into its effects on hair growth over the past two decades, a breakthrough study has now discovered that by activating our sonic hedgehog we may be able to prevent hair loss
related to ageing.
What is the Sonic hedgehog in humans?
Officially classified as a protein belonging to the mammalian signalling pathway, the sonic hedgehog is a protein which is encoded by a Sonic hedgehog gene (SHH); together they are referred to as Shh.
It is responsible for cell division of adult stem cells and plays a key role in human development, particularly that of the brain, spinal cord, central nervous system, teeth, lungs and growing digits. As such, it is especially active in foetuses but can slow or stall as we age, or where the skin becomes wounded.
How does the Sonic hedgehog pathway affect hair growth?
One of the affects of ageing is thinning hair
which can present in both men and women. This includes those who are not already losing their hair to the hereditary conditions Male Pattern Baldness
or Female Pattern Hair Loss
, which are genetic but become increasingly prevalent from middle-age onward.
Often known as senescent alopecia
, various clinical studies have linked age-related hairloss to decreasing collagen production
as we get older, given collagen is vital for strong, healthy hair. This is not to be confused with 'hair ageing
' which can happen at any time and tends to be more environmental.
The Sonic hedgehog pathway carries messages between cells, including communicating with fibroblasts - those responsible for collagen production.
Can the Sonic hedgehog regrow hair or prevent hair loss?
Researchers from the Ronald O. Perelman Department of Dermatology and Department of Cell Biology at the New York University School of Medicine have now discovered that hair loss and hair thinning as a consequence of ageing is a 'signalling issue'. This conclusion was arrived at after animal trials were carried out by the team, investigating healing responses to wounds in mice.
Given wounds in mammals often heal without affected hair follicles (HF) being restored, in their finished paper - published in the Nature Communications
medical journal - it states the aim of the study was to "determine if scar could be remodeled to promote healing with HF regeneration." Noting that, at the point before their research began, "Fibrosis and regeneration are currently considered the opposite end of wound healing".
By activating the Sonic hedgehog pathway so that it would communicate with the fibroblasts and activate signals in Wnt active cells
at the point of hair follicle growth - the dermal papillae - only, both wound healing and hair follicle regeneration were observed. "These studies demonstrate that mechanisms of scarring and regeneration are not distant from one another and that wound repair can be redirected to promote regeneration following injury by modifying a key dermal signal," concludes the paper.
"Now we know it's a signalling issue in cells that are very active as we develop in the womb, but less so in mature skin cells as we age,"
comments lead study author, Dr. Mayumi Ito in the Mail Online. "Our results show stimulating fibroblasts through the sonic hedgehog pathway can trigger hair growth not previously seen in wound healing."
Whilst the authors hope this new information could lead to novel ways of treating hair loss as a result of ageing, it also has the potential applications for another - and currently untreatable - condition, Cicatricial Alopecia
. This is baldness caused by scarring, generally as a result of underlying inflammation or environmental factors such as burns from fire or radiation.
Although it is likely to be some years before this initial information is put to use as any recognised hair loss treatment
, it is certainly an interesting development and one which could help a great many people who currently have limited options. For those with thinning hair that is non-scarring, there are a number of clinically-proven hair loss solutions available and personalised recommendations can be made following consultation with a specialist.