Dr. Dagnino’s research focus is on skin biology and stem cells. Her expertise includes cellular and molecular biology, as well as developmental genetics.
The skin is the largest organ in the body. It weighs 6-9 pounds and, if one could take it off and lay it flat, it would cover an area of about 20 ft2 (2 m2). The skin fulfills myriad functions. It serves as a barrier between the body and the outside environment, protecting it from chemicals, physical damage, and entry of infectious organisms. It also prevents dehydration and heat loss, and allows perception of touch, a quintessential source of sensory stimulation. Three layers form the skin. The uppermost layer is the epidermis, which is formed by epithelial cells called keratinocytes.
These cells also form hair, nails, teeth and sebaceous glands. Keratinocyte stem cells constantly differentiate and migrate from the base of the epidermis towards the outer surface of the skin, where they are sloughed off. This process normally takes about a month, but in people suffering from skin disorders, such as psoriasis, it can be accelerated, sometimes occurring in a few days. Over 30,000 cells are shed from the skin every minute, and the skin can be maintained only because it has a large reservoir of keratinocyte stem cells.
Dr. Dagnino’s laboratory works on the mechanisms that are involved in cellular decisions to maintain an undifferentiated, stem-cell phenotype or follow a pathway of terminal differentiation in the keratinocytes of the epidermis. Her group is currently investigating how those mechanisms regulate normal regeneration after wounding, abnormal proliferation and cancer, as well as how they contribute to block microbial invasion.