Stiffness measurement is a biomarker of skin aging in vivo.

Human skin is particularly vulnerable to age-related deterioration and undergoes profound structural and functional changes, reflected in the external skin appearance. Skin aging is characterized by features such as wrinkling or loss of elasticity. Even if research advances have been done concerning the molecular mechanisms that underlie these changes, very few studies have been conducted concerning the structure stiffness of the skin organ as a whole. In this study, we showed, thanks to human skin reconstructs and the Japanese Medaka fish model, that biomechanics is a new biomarker of skin aging. We revealed that global stiffness measurement by Atomic Force Microscopy, since modulated through aging in these models, can be a new biomarker of skin aging, and reflects the profound reorganization of the dermis extracellular matrix, as shown by Transmission Electron Microscopy. Moreover, our data unveiled that the Japanese Medaka fish could represent a highly relevant integrated model to study skin aging in vivo.