Decreased fibroblast contractile activity and reduced fibronectin expression are involved in skin photoaging

Skin aging is the result of both intrinsic and extrinsic factors. Extrinsic aging is mainly due to photo-damage caused by ultraviolet (UV) irradiation. A characteristic feature of photo-damaged skin is the deterioration of the dermal connective tissue. On the histological level fragmentation of interstitial collagens is observed [1] which substantially contributes to the reduction of skin's tensile strength [2]. While young dermal fibroblasts exhibit a sufficient capacity to adequately maintain the homeostasis of the extra cellular matrix (ECM), (photo)-aged fibroblasts not only display a decrease of their synthetic activity but are also reduced in number [3].