Scientists from the Barcelona Institute for Research in Biomedicine (IRB) and the National Center for Genomic Analysis (CNAG) have discovered that the IL-17 protein plays a determining role in the skin aging process and that blocking its function reduces the pro-inflammatory state and delays the appearance of age-related traits.
The discovery, published in the journal Nature Aging, opens new perspectives for developing therapies to improve skin health, according to the researchers, led by Dr.. Guiomar Solanas, Salvador Aznar Benitah, both from the IRB, and Holger Heyn, from the CNAG.
Researchers have recalled that skin aging is characterized by a series of structural and functional changes that gradually contribute to the deterioration and fragility associated with age.
Aging skin has reduced regenerative capacity, poor healing and diminished barrier function, according to the scientists, who have described the changes that different types of cells undergo with aging and, specifically, have identified how some immune cells skin have elevated levels of IL-17.
“Our results show that IL-17 is involved in various functions related to aging and that by blocking this protein the appearance of various deficiencies associated with aging skin is slowed down, and this opens up new possibilities for treating some of the symptoms or facilitating recovery. of the skin after surgery, for example”, highlighted Aznar Benitah, who is head of the Stem Cells and Cancer laboratory at the IRB.
“Single cell sequencing has allowed us to delve into the complexity of cell types and states that make up the skin and how these change throughout life.. We found not only differences in the composition of aging skin, but also changes in the activity states of the cells,” added Holger Heyn, head of the CNAG Single Cell Genomics laboratory.
According to Heyn, in addition to a wide variety of epithelial cells, hair follicle cells, and other components, the skin also houses cells of the immune system, which play a crucial role in preventing infection and protecting against further insults.
This work describes how, during aging, some of these immune cells, specifically gamma delta T cells, innate lymphoid cells and CD4+ T cells, significantly increase their presence in the skin.. These same cells also show very high levels of the proinflammatory cytokine IL-17.
“Aging is associated with a situation of mild but persistent inflammation, and in the skin this is characterized by a significant increase in IL-17, which causes deterioration in the skin,” Paloma Solá, first author of the study, detailed in in which Elisabetta Mereu, now a researcher at the Josep Carreras Leukemia Research Institute, has also participated.
Psoriasis-related protein
Previous studies had already described that IL-17 is related to some autoimmune skin diseases, such as psoriasis, and there are treatments that precisely block this protein.
The scientists studied the response to blocking treatment of IL-17 activity in several aspects, including hair follicle growth, transepidermal water loss, wound healing, and genetic markers of aging.. These four parameters showed an improvement after treatment, as the acquisition of these aging traits was delayed.
“The IL-17 protein is essential for vital functions in the body, such as defense against microbes or wound healing, so permanently blocking it would not be an option.. What we have observed is that its temporary inhibition offers benefits that could be interesting at a therapeutic level”, concluded the researcher Guiomar Solanas.
The IRB scientists are now thinking of investigating which aging processes are related to inflammatory states in the skin and how these are linked to IL-17, in addition to trying to find out if this protein plays a role in the aging and deterioration of other tissues and organs..