302 Targeting perfect skin repair markers in a model of induced cellular senescence

Abstract

Skin repair is a multistep process involving both epidermal and dermal compartments. Among the sequential and overlapping events that take place during the skin repair process, the regeneration of the epidermal compartment represents a critical step for a complete and effective repair, described here as “perfect skin repair”. In the present study, we evaluated an extract of Rosa centifolia, prepared using a proprietary extraction progress, that is rich in small RNA and compounds of interest including. This extract was evaluated for its effects on markers associated with skin repair, on normal aged human keratinocytes. MARCKS like protein (MARCKSL1) is a regeneration-initiating protein, discovered in axolotl, an amphibian species known for its scar-free healing capacity. MARCKSL1 is also expressed in human skin. Among the different miRNAs implicated in skin repair, miR-132 has been described as critical to improve skin regeneration, playing a role in the transition between the inflammatory phase and epidermal restoration. In the model of induced cellular senescence, we observed a decrease in MARCKSL1 and miR-132 expressions and a slowdown of cell migration in a scratch test assay. When senescent keratinocytes were treated with the extract of Rosa centifolia, the marker of perfect skin repair MARCKSL1, as well as the level of miR-132, were observed to have increased. The ability of senescent keratinocytes to regenerate a scratched monolayer was also observed to have improved after application of the extract. Some dermal markers associated with skin repair such as collagen I, fibronectin and hyaluronic acid were increased in ex vivo skin biopsies that had been treated with the extract. In conclusion, the extract of Rosa centifolia was shown to act on markers of the early phase of skin repair, associated with epidermal restoration, as well as components of the extracellular matrix. Taken together, these effects are in favor of optimizing skin repair especially in aged or compromised skin.