Proteom encompasses the full set of proteins in a cell and in an organism. It is a highly dynamic system that maintains its homeostasis, called proteostasis. In case of loss of proteostasis, impaired proteins accumulate, aggregate and/or saturate detoxifying systems leading to proteotoxicity which is a hallmark of ageing, involved in most age-related diseases and in skin ageing. Thereby, protection of the skin proteome is a key challenge to keep a healthy skin and fight accelerated aging. We discovered and characterized a snow bacteria extract (SBE) that displays protective effect on the proteome under stressful conditions. SBE is an extract from A. agilis obtained from Paris snowflakes, rich in 6 different forms of an original protective pigment: bacterioruberin. To better understand the mode of protection of SBE, we studied its ability to bind BSA by HPLC and could observed an interaction. Protection through a binding of proteins reminded us of the chaperone mode of action. To test this hypothesis, we looked at the capacity of SBE to protect an enzyme activity against a specific, non-oxidative stress (heat shock). SBE was able to protect the enzyme and preserved its activity (>80% vs 0% without) despite the temperature shock, validating the chaperone-like activity. We next looked at the protective effect of SBE on the skin against damages induced by daily stresses. SBE was able to highly decrease (2.5 to 4-fold) protein carbonylation induced by UV, blue light or pollution on cultured keratinocytes. Furthermore, SBE was able to completely prevent carbonylation of proteins in an explant submitted to UV and pollution. Finally, SBE could prevent UV induced elastin aggregation in tubo and elastin degradation caused by UV and pollution on explant (100% protection vs 30% for placebo). Our results show that SBE possess a chaperone-like activity that allows a significant protection of the proteome, making it an innovative ally to fight against the wide variety of everyday life stresses that leads to premature aging of our skin.

ESDR150 - Skin proteom protection through the chaperone-like activity of an A. agilis extract

50th Annual Meeting of the European Society for Dermatological Research. VIRTUAL MEETING