Mechanical tension stimulates the transdifferentiation of fibroblasts into myofibroblasts in human burn scars

Scar formation as a result of burn wounds leads to contraction of the formed granulation tissue, which causes both aesthetic and functional impairment for the patient. Currently, the main treatment methods focus on stretching to prevent tissue contraction. The myofibroblasts play a key role in the contraction of granulation tissue during scar formation, but their presence should normally decrease after wound re-epithelialization. In hypertrophic scars the myofibroblasts persist and is believed to cause further hypertrophy. Previous studies have shown that mechanical tension leads to increased myofibroblast numbers in granulation tissue. In order to evaluate the effect mechanical tension as a result of stretching has on the number of myofibroblasts in burn wound scars, an in vitro model was used. This model used human burn scar biopsies which were stretched and examined after 1 and 6 days to evaluate the effect on the number of myofibroblasts. The stretching caused an increase in the number of myofibroblasts after mechanical stimulation. This indicates that mechanical stimulation using stretching induces fibroblast to myofibroblast transdifferentiation, thus underlining the importance of further investigations of optimal methods of this regime for treating burn scars.