Skin aging is associated with changes in both the mechanical properties of the skin and extracellular matrix (ECM) components. In this study, we investigated the relationships between mechanical property and aging biomarkers in passaged human dermal fibroblasts (HDFs). The stiffness of HDFs from passages 5-20 was assessed by atomic force microscopy. The ECM components including collagen, elastin, and fibrillin-1 and that of signaling molecules (SIRTs) were determined from each passage of cells. The stiffness of HDFs increased linearly from passages 5-15 and then became saturated: the average stiffness was 0.356 N/m at passages 5 and 1.186 N/m at passages 15, respectively. Expression of all aging biomarkers, including pro-collagen I and VII, elastin, fibrillin-1, and SIRT1 and SIRT6, were down-regulated by passaging. In particular, a change in the level of procollagen Type I was significantly associated with early aging, while a change in the level of fibrillin-1 was associated with late aging. All biomarkers except elastin showed a strong correlation with the cellular stiffness of HDFs.
Keywords: aging-biomarker; atomic force microscopy; fibroblast; mechanical property; sirtuin.
© 2015 Wiley Periodicals, Inc.