A scientific team from the Institute for Research in Biomedicine (IRB Barcelona) in collaboration with the National Center for Genomic Analysis (CNAG) discovered that the IL-17 protein plays a central role in the skin aging process.
The study, led by Guiomar Solanas, Salvador Aznar Benitah, both from IRB Barcelona, and Holger Heyn from CNAG, associate this aging process, mediated by IL-17, with an inflammatory state.
Skin aging is characterized by a series of structural and functional alterations that gradually contribute to the age-associated deterioration and frailty. Aging skin has a lower regenerative capacity, poor wound healing and a diminished barrier function.
This work published in the journal Nature Aging describes the changes experienced by different cell types with aging, and specifically identifies how some immune cells skin have elevated levels of IL-17.
“Our results show that IL-17 is involved in several functions related to aging. We have seen that blocking this protein delays the onset of various deficiencies associated with skin aging. This discovery opens up new possibilities for treating some of the symptoms or facilitating skin recovery after surgery, for example,” he explains. Aznar Benitahresearcher at ICREA and head of the Stem Cells and Cancer laboratory at IRB Barcelona.
We have seen that blocking this protein delays the onset of various deficiencies associated with skin aging.
“Single-cell sequencing allowed us to delve into the complexity of the cell types and states that make up skin and how they change throughout life. We found not only differences in the composition of aging skin, but also changes in cell activity states. In particular, the immune cells showed specific age-related profiles, which we were able to identify by analyzing thousands of individual cells at a time,” he says. holger heynhead of the Single Cell Genomics laboratory at CNAG.
Immune cells, inflammation and aging
In addition to a wide variety of epithelial cells, follicular cells and other components, the skin also houses immune system cellsthat play a crucial role in preventing infections and protecting against further aggression.
The paper describes how, during aging, some of these immune cells, specifically gamma delta T cells, innate lymphoid cells and CD4+ T cells, significantly increase your presence in the skin. These same cells also have very high levels of the pro-inflammatory 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 of the skin”, he explains. dove alonefirst author of the article, along with Elisabetta Mereuresearcher at the Josep Carreras Leukemia Research Institute.
Reverse the symptoms of aging
Previous studies had already described that IL-17 is related to some autoimmune skin diseases, such as psoriasis, and there are treatments that block precisely this protein. The scientific team studied the treatment response of blocking IL-17 activity in different 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 characteristics was delayed.
“The IL-17 protein is essential for vital functions in the body, such as defending against microbes or healing wounds, so permanently blocking it would not be an option. What we have observed is that its temporary inhibition offers benefits that can be interesting at a therapeutic level”, he concludes. Guiomar Solanasfrom the IRB Barcelona.
Future laboratory work will focus on clarifying which aging processes are related to inflammatory states in the skin and how they are linked to IL-17. The team will also investigate whether IL-17 plays a role in aging and the deterioration of other tissues and organs.
Paloma Solá, Elisabetta Mereu, et al. “Local IL-17 orchestrates skin aging.” Nature Aging (2022)