The protease-activated receptors, PARs for short, are a family of G protein-coupled receptors (GPCK) that are characterized by the fact that they are activated by serine proteases (mainly thrombin, in the epidermis also by kallikreins). In addition to their role in blood coagulation, protease-activated receptors are also involved in inflammatory and digestive processes. Protease-activated receptors are expressed by various cell types, including thrombocytes, endothelial cells, myocytes and neurons.
Keratinocyte proliferation leads to increased expression and activation of PAR2. Inhibition and deletion of PAR2 leads to a significant suppression of inflammation and oxidative stress, which is accompanied by a reduction in IL-6 and IL-1β levels and an increase in MnSOD levels (Bang E et al. 2021).