While scars might be aesthetically undesirable (or perhaps desirable) externally, they also represent functional defects, particularly when scar tissue occurs in organs such as the heart - creating a loss of function and elasticity. Research on a cell signalling pathway common to mammals has now uncovered a signalling pathway and specific protein however, which might act as a regulator in regeneration.
When damaged, skin appears to release double stranded RNA (dsRNA), a molecule which many viruses also carry. This is registered by a particular receptor, TLR3, which helps recognise pathogens and activate an immune response. This receptor also seems to activate hair follicle regeneration and has links to skin development. Interestingly, research discovered that in groups of mice that undergo proficient wound healing, expression of TLR3 was 3 times higher, rendering the tissue more sensitive to damage.
"A lot of human disability is from scarring. After a heart attack, we're really good at replacing the blood flow, but it's the scar on the heart afterward that's the real problem.
Adding additional, synthetic dsRNA to wounded tissue was also able to increase regeneration, whereas reducing quantities instead impaired it; it may be by targeting this receptor, regeneration can be increased in damaged skin in particular. As these pathways are revealed, they offer new ways of avoiding scar tissue and ensuring effective repair, potentially externally and internally.
"One implication from our work is that all of those different rejuvenation techniques are likely working through dsRNA pathways. It may also be that dsRNA could be directly used to stimulate rejuvenation in aging or hair follicle growth in burn patients to regain structures that have been lost."
Read more at International Business Times