The pattern recognition receptor toll-like receptor 3 regulates skin barrier homeostasis

The study explored the role of Toll-like receptor 3 (TLR3) in skin barrier repair following UV injury, finding that TLR3 activation by double-stranded RNA (dsRNA) from damaged keratinocytes increased the expression of genes involved in skin barrier repair, such as ABCA12 and glucocerebrosidase. TLR3 also enhanced tight junction function and lipid production in keratinocytes. Tlr3-/- mice showed delayed skin barrier repair, highlighting TLR3's role in this process. Additionally, scavenger receptors were found to facilitate dsRNA entry into keratinocytes, influencing gene expression related to barrier repair. Msr1-/- mice exhibited skin barrier repair defects, indicating scavenger receptors' importance. The study also noted that IL-1R signaling, while necessary for barrier disruption post-UVB exposure, did not significantly affect the upregulation of repair genes, though Il1r-/- mice developed hair cysts and had fewer macrophages. These findings enhanced the understanding of skin's cellular response to UVB damage.