The use of tissue-engineered skin to demonstrate the negative effect of CXCL5 on epidermal ultraviolet radiation-induced cyclobutane pyrimidine dimer repair efficiency.

Background: Ultraviolet radiation (UVR) is responsible for keratinocyte cancers through the induction of mutagenic cyclobutane pyrimidine dimers (CPDs). Many factors influence CPD repair in epidermal keratinocytes, and a better understanding of those factors might lead to prevention strategies against skin cancer.
Objectives: To evaluate the impact of dermal components on epidermal CPD repair efficiency and to investigate potential factors responsible for the dermal-epidermal crosstalk modulating UVR-induced DNA damage repair in keratinocytes.
Methods: A model of self-assembled tissue-engineered skin containing human primary keratinocytes and fibroblasts was used in this study.
Results: We showed that CPD repair in keratinocytes is positively influenced by the presence of a dermis. We investigated the secretome and found that the cytokine CXCL5 is virtually absent from the culture medium of reconstructed skin, compared with media from fibroblasts and keratinocytes alone. By modulating CXCL5 levels in culture media of keratinocytes, we have shown that CXCL5 is an inhibitor of CPD repair.
Conclusions: This work outlines the impact of the secreted dermal components on epidermal UVR-induced DNA damage repair and sheds light on a novel role of CXCL5 in CPD repair.
(© 2020 British Association of Dermatologists.)