Impaired tight junctions obstruct stratum corneum formation by altering polar lipid and profilaggrin processing.

Background: The stratum corneum (SC) is a well-known structure responsible for the cutaneous barrier. Tight junctions (TJs) function as a paracellular barrier beneath the SC and are involved in the cutaneous barrier. It remains unclear how TJs are involved in the cutaneous barrier.

The presence of N(ε)-(Carboxymethyl) lysine in the human epidermis.

It is well known that advanced glycation end products (AGEs) are formed in long-lived dermal proteins such as collagen, and that their formation is related to skin aging. To examine the distribution of AGEs in skin tissue, we performed immunofluorescence studies on the human skin using an anti-AGEs antibody. Interestingly, AGEs signals were observed not only in the dermis but also in the epidermis.