From amphibians to fish, many animals can naturally regenerate lost tissue. But for humans, this is a little trickier. Now, researchers may have found a way to manipulate wounds so that they heal as regenerated skin rather than scar tissue.
One of the main reasons that wounds heal as scar tissue is due to the type of cell that develops at the damaged site. Known as myofibroblasts, they are found just under the surface of mucosal layers in many parts of the body, and during healing they help strengthen the wound by adding collagen fibers. It is this extra collagen that adds to the scaring and deformation of the skin.
When the skin heals, it also fails to develop hair follicles, which contributes to why scar tissue looks abnormal compared to healthy skin. This was one of the factors that intrigued the researchers looking into new ways to alter the process of wound healing. They found that by making healing tissue produce hair follicles, this led to the development of fat cells from the myofibroblasts and consequently prevented major scarring.
“Typically, myofibroblasts were thought to be incapable of becoming a different type of cell,” explains George Cotsarelis, who co-authored the study published in Science, in a statement. “But our work shows we have the ability to influence these cells, and that they can be efficiently and stably converted into [fat cells].”
The team have already found the factors necessary for follicles to develop, which occur via the signalling pathways of particular proteins. But it was what occurred after this that surprised them. They found that the development of fat cells (adipocytes) required the new hairs to form first, and that the follicles influenced this transformation by sending a signal in the form of a factor known as Bone Morphogenetic Protein (BMP).
“The findings show we have a window of opportunity after wounding to influence the tissue to regenerate,” says Maksim Plikus, who led the study. But the research doesn’t only have implications for wound healing. The loss of fat cells is common for a whole range of other conditions, and figuring out how to replenish them could be vital. Many treatments for HIV, for example, lead to the loss of fat, as well as contribute to the aging process by resulting in deep wrinkles.