P41 Characterizing the impact of ageing/inflammaging on autophagy integrity in the skin

Abstract Introduction and aims Epidermal homeostasis maintains skin functional integrity. Extrinsic and intrinsic factors can contribute to an increased chronic inflammatory profile (termed ‘inflammaging’), disruption of skin homeostasis, and an overall decline in skin structure and function. One metabolic signalling pathway involved in maintaining skin homeostasis is autophagy, in which subcellular components are degraded and recycled in a lysosomal-dependant manner. While it has long been understood that ageing is associated with disease and decline, precisely how ageing and inflammaging impacts key modulators of homeostasis, such as autophagy, in the skin remains to be clarified. Methods To investigate how inflammaging may impact autophagy integrity in the skin, the present study used primary dermal fibroblasts (DFs) isolated from human skin from eight donors segregated by age to assess key autophagic markers at steady state. DFs from each donor were cultured in normal Dulbecco’s Modified Eagle Medium media, lysed and following protein extraction, autophagy-related proteins (including lysosomal markers, cargo proteins and autophagosome markers) were assessed by Western blot analysis. Results Preliminary data reveal higher expression patterns of lysosomal markers from DFs derived from younger donors when compared with older donor DFs. Furthermore, cargo proteins showed a tendency to decrease in protein expression in younger donors when compared with DFs derived from older donors. However, little difference was observed in steady-state LC3I and LC3II expression when DFs from younger donors were compared with older donors. Conclusions Taken together, increased lysosomal marker expression and decreased cargo proteins expression in younger donors at steady state suggest decreased lysosomal functional integrity within older donors when compared with younger donors and may yet provide insight into how homeostasis is disrupted in the skin during ageing.