Researchers have identified a new stem cell population in the skin epidermis that is responsible for tissue repair. The finding could lead to new wound care treatments, they say.

Belgian researchers said the newly found stem cells ensure the daily maintenance of the epidermis and illustrate the significant contribution of epidermal stem cells during wound healing.

The skin, which is an essential barrier that protects the body against the external environment, undergoes constant turnover throughout life to replace dead cells that are constantly sloughed off from the skin surface. 

During adult life, the number of cells produced must exactly compensate the number of cells lost. 

In this new study, investigators used novel genetic lineage tracing experiments to fluorescently mark two distinct epidermal cell populations, and follow their survival and contribution to the maintenance of the epidermis overtime. 

While doing this, they uncovered the existence of two types of dividing cells. 

One population of proliferative cells presented very long-term survival potential while the other population is progressively lost over time.

Investigators found that the skin epidermis is hierarchically organized with slow-cycling stem cells residing on the top of the cellular hierarchy that give rise to more rapidly cycling progenitor cells that ensure the daily maintenance of the skin epidermis.