Oxidative stress plays a pivotal role in skin disease, including in vitiligo and skin cancer development. Melanin is a known scavenger of reactive oxygen species (ROS) but can also, depending on skin phototype, drive ROS generation. Protease-Activated Receptor (PAR)-2 is understood to participate in melanin transfer from melanocytes to keratinocytes, a process that can provides ROS- and UVR-protection to keratinocytes. In this study we evaluated the effect of PAR receptor signalling modulation on ROS formation, after exposing human skin histocultures to UVR or the pro-oxidants H2O2 or Buthionine sulfoximine for exogenous and endogenous ROS induction respectively. Using a novel assay based on in vivo imaging system through L-012 probing, we were able to quantify accumulation of ROS after induction of oxidative stress in ex vivo human skin biopsies. We observed that different skin phototypes respond differently to oxidative stress induction and PAR-2 signalling modulation. Lighter skins generated more ROS and had lower catalase activity than darker skin phototypes. Additionally, we preformed full proteomics analysis of cultured ex vivo skin biopsies and compared the profiles with lesional and non-lesional vitiligo patient skin for the first time.
Our data suggest that oxidative stress and PAR-2 signalling modulation have different cellular responses in fair-skinned versus darker-skin individuals. These observations suggest that PAR-2 signalling differentially participates in the handling of oxidative stress according to skin phototype. In summary, we propose a novel mechanism whereby PAR-2 controls the redox environment of human skin epidermis beyond its contribution to melanin transfer.

LB030 - Role of Protease-Activated Receptor 2 signalling in oxidative stress handling in the epidermis of human skin of different phototype

The scientific meeting of the European Society for Dermatological Research (ESDR) is held yearly, usually in September. With an international attendance of more than 1000 skin scientists from around the globe, the four-day event includes short oral presentations from peer-reviewed abstracts, keynote lectures from international experts, sponsored symposia, satellite programs, educational events as well as an important focus on posters, networking and building collaborations amongst scientists. For more information about this year’s meeting visit our website.