Scars are created by the reparative mechanisms of the body to heal a wound. The amount of scar tissue created varies based on a variety of factors. While effective at sealing and healing the wounds, the scar tissue is not normal and is not an exact replica of the tissue that it replaces or that surrounds it.
The surgical approach to scars is one basic method…cut it out and hope that less scar tissuemforms in its place. Or is some cases of scar revision a new line of closure is done so that it lays differently in the skin so that it may be less visible using the natural skin lines.
A newer approach to the treatment of scars is that of fat injections. The concept is to introduce new healthy cells (adipocytes, fibroblasts and some stem cells) that could potentially create new tissue that is more soft and supple. By breaking up the scar tissue and doing a secondary scar excision/revision if needed the scarred wound environment is changed. While this approach is theoretically appealing and there is lots of anecdotal clinical experience/results that provide support for its treatment benefits, the actual cellular biology of his approach is not well understood.
In the January 5th 2017 issue of the journal Science, an article was published entitled ‘Regeneration of Fat Cells from Myofibroblasts in Wound Healing’. In mice studies it was discovered that during wound healing fat cells (adipocytes) were regenerated from myofibroblasts. This was striking because scar tissue does not contain fat (or hair follicles) and that myofibroblasts are thought to be fully differentiated and incapable of being transformed into other types of cells. The myofibroblast is the most common cell type found in scars. Such myofibroblast reprogramming required hair follicles to trigger BMP signaling and subsequent activation of adipocyte transcription factors. Fat cells formed from human keloid fibroblasts when treated with either BMP or when placed with human hair follicle. Thus, the myofibroblast is a cell type that can be manipulated to treat scars in humans.
The theoretical benefits of these findings is that wound healing may be capable of being manipulated to create actual skin regeneration rather than scar tissue. Hair follicles have to be regenerated first after which fat can be formed. Factors are released from the hair follicles which causes myofibroblasts to create fat rather than scar tissue. The fat will not form without the new hairs, but once it does, the newly created fat gives the healed wound a natural appearance instead of leaving a scar.
Could drugs and treatment strategies be developed to turn myofibroblasts into fat and help wounds to heal without scarring? This is certainly the direction that this research suggests. Does this have any relevance to injecting fat into and around scarred tissues? Not exactly but treating early scar tissue formation with fat injections, as is commonly done today, may have a biologic basis after all.
Dr. Barry Eppley
Indianapolis, Indiana