The results of new Spanish research indicate that the pro-inflammatory cytokine IL-17 is central to skin aging and could potentially be targeted to prevent age-related skin changes.
This mouse skin study, from the Institute for Research in Biomedicine (IRB Barcelona) in collaboration with the National Center for Genomic Analysis (CNAG), reports that aging skin shows signs of chronic inflammation caused by IL-17. The paper was published in Nature Aging.
During aging, certain immune cells such as gamma delta T cells, innate lymphoid cells, and CD4+ T cells significantly increase in the skin and start expressing high levels of IL-17. These high levels of IL-17 promote an inflammatory state, the investigators wrote. Dr. Paloma Solá, first author of the paper with Dr. Elisabetta Mereu, said that aging is associated with mild but persistent inflammation and, in the skin, this is characterized by a significant increase in IL-17, which causes skin deterioration.
"Our results show that IL-17 is involved in various functions related to aging. We have observed that blocking the function of this protein slows down the appearance of various deficiencies associated with aging skin,” said Dr. Aznar Benitah, head of the Stem Cells and Cancer laboratory at IRB Barcelona, in a press release. “This discovery opens up new possibilities for treating some of the symptoms or facilitating skin recovery after surgery, for example."
IL-17 is involved in certain autoimmune skin diseases, such as psoriasis, and there are existing treatments that block this protein. In this study, the researchers evaluated the response of hair follicle growth, transepidermal water loss, wound healing, and genetic markers of aging when IL-17 was blocked. They determined the development of these aging traits was significantly delayed.
"The IL-17 protein is essential for vital body functions, such as defence against microbes and wound healing, so permanently blocking it would not be an option,” said Dr. Guiomar Solanas, an associate researcher at IRB Barcelona, in the press release. “What we have observed is that its temporary inhibition offers benefits that could be of interest at a therapeutic level."
The researchers are continuing to try to clarify the aging processes related to inflammatory states in the skin and how these are linked to IL-17.