Longevity Briefs: Reversing Scarring With Hair Follicles

Longevity briefs provides a short summary of novel research in biology, medicine, or biotechnology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.

Why is this research important: Hair follicles are the tiny shafts on the surface of the skin from which hair grows. You might not know that hair follicles are also important in skin healing. When skin is damaged, various cells including stem cells migrate out from the hair follicles in order to regenerate lost tissue. Previous studies have shown that hairy skin heals faster, and healing can even be accelerated using hair transplants.

Scar tissue is a type of tissue that can form when a wound heals. Unlike the tissue that it replaces, scar tissue is mainly made of fibrous connective tissue high in collagen, and lacks blood vessels and nerves. It is usually less flexible than normal tissue, and when scarring occurs within internal organs, it can disrupt their ability to function. Some scars do remodel back into normal tissue by themselves, but so-called mature scars do not, and treatments aimed at reversing scarring aren’t very effective.

What did the researchers do: In this study, researchers wanted to see if implanting hair follicles during their growth phase (anagen phase) into scar tissue would help remodel that scar tissue back into normal tissue. The study had just three participants who were recruited back in 2017. They all had scars on their scalps, and these were all normotrophic scars – the most common type of scar, normally occurring after surgery. The researchers took tissue biopsies before and during the 6 months following transplantation.

Key takeaway(s) from this research: Transplantation was associated with positive changes in skin structure and the expression of genes associated with healthy skin:

• The outer layer of the skin (epidermis) doubled in thickness
• The number of blood vessels within the next layer down (the dermis) increased almost to healthy levels
• Collagen density decreased, making the scar tissue less stiff
• The expression of 719 genes was altered. Genes promoting cell and blood vessel growth were expressed more, while genes promoting scar-forming processes were expressed less

This was obviously a very small study, and there was no control group, but it seems unlikely that the changes that occurred could have been the result of anything other than the introduction of hair follicles. More studies will be needed but, if successful, this research could lead to treatments not only to reverse scarring of the skin but also of internal organs.