J. Sage, M. Moreau, M. Juan, C. Marteau, L. Sobilo, E. Leblanc, C. Brun, M. Dumas, C. Heusèle, A.-L. Bulteau, C. Nizard, K. Pays

The exposome encompasses environmental exposures (pollution, UV radiation, temperature changes and lifestyle factors) individuals encounter throughout life. The skin, being directly exposed to the environment, is significantly affected by the exposome, which studies link to accelerated skin ageing and diseases.
To investigate the exposome’s impact we employed diverse experimental approaches with increasingly sophisticated models, including primary cell cultures, human reconstructed skin and skin explants, exposed to different types of stressors. We used biochemical assays to examine oxidative stress and evaluated changes in skin structure and levels of key proteins using immunohistochemistry techniques. We conducted a clinical study focusing on sleep deprivation to further explored in vivo skin parameters.
Our findings demonstrated that environmental stressors induce oxidative stress and alters skin integrity and morphology. This includes the accumulation of oxidized proteins and lipids, reduced antioxidant defenses, and compromised mitochondrial function and protein degradation systems. Structural changes like decreased collagen density and altered epidermal structure were also observed. Furthermore, sleep restriction notably altered skin and facial appearance.
These studies confirm the exposome's crucial role in skin ageing by inducing molecular and structural damage, emphasizing the importance of better understanding it to develop targeted strategies to prevent and limit its harmful effects.