Comparison of fibrogenesis caused by dermal and adipose tissue injury in an experimental model

Mammalian skin is composed of three layers, the epidermis, the dermis, and the subcutis, which is composed primarily of adipose tissue. The dermal and adipose tissues are involved simultaneously when partial and full-thickness burns occur, and often induce scar formation. However, little is known about the role of the dermis and adipose tissue injury in scar formation or the difference in fibrogenesis between the two tissues. In this study with female red Duroc pigs, we created flaps of skin with a dermal plane of injury or deeper flaps with an adipose plane of injury on the back. We compared the extent of fibrogenesis by observing the deposition of extracellular matrix as well as the characteristics of cells in the injured area. In skin flaps with a dermal level of tissue injury, scar formation that was characterized by more extracellular matrix deposition and less apoptotic myofibroblasts in the injured area was observed. Our results suggest that scar formation does not correlate with injury at the level of the adipose tissue, and that adipose tissue might serve to alleviate fibrogenesis.