Session: Session 5

Advanced Analytical Characterization of Lipidome Alterations in an In Vitro Skin Model Following Solar Irradiation

Carine JACQUES¹, Maureen FEUCHEROLLES², William LE², Jerôme BOUR², Camille GÉNIÈS¹, Camille BOUDET³, Gautier DOAT³, Gilles FRACHE³, Hélène DUPLAN¹

¹Pierre Fabre Dermo-Cosmétique, Pierre Fabre R&D Center, Applied Research Department, Toulouse, France
²Luxembourg Institute of Science and Technology (LIST), Molecular and Thermal Analysis Group, Materials Research and Technology, Belvaux, Luxembourg
³Laboratoires Eau Thermale Avène, Lavaur, France

Solar irradiation can lead to harmful effects, such as skin aging and cancer. Therefore, understanding the skin composition and the molecular mechanisms underlying UV-induced damage is crucial.

We measured the impact of sun exposure on the skin lipidome in a reconstructed human epithelial (RHE) in vitro model, as well as the protective role of a commercial SPF50+ sunscreen on the lipid modulations. MALDI-MSI was used to locate several lipids identified using LC-MS/MS to determine changes in their distribution in the skin.

There were 252 lipids in RHE models statistically significantly deregulated by irradiation, including multiple phospholipids classes, triacylglycerols, diacylglycerols, sphingolipids and ceramides. Of these, only four were still statistically significantly modulated when the sunscreen was applied prior to irradiation. MALDI-MSI imaging of control RHE sections alongside optical images revealed the presence of 4115 biomarkers with annotations based on the LipidMaps database associated with distinct areas in the tissue. One key biomarker linked to keratinocyte differentiation during photoaging, 25-hydroxycholesterol, was present in low levels in control RHE models but increased significantly after irradiation. The increase was prevented by applying sunscreen prior to irradiation.

In conclusion, a combination of LC-MS/MS and MALDI-MSI enabled the quantitative analysis of biomarkers of key pathways altered by irradiation, as well as their location in the skin. Importantly, the SPF50+ sunscreen exhibited a protective effect on skin lipidome against modulations due to irradiation. This technology will enable biomarker and pathway-specific events in the skin to be monitored after different treatments.