Toll-like Receptor 3 Agonist, Polyinosinic-polycytidylic Acid, Upregulates Carbonic Anhydrase II in Human Keratinocytes.

Carbonic anhydrases are ubiquitously expressed enzymes that reversibly hydrate carbon dioxide to bicarbonate and protons. While the main function of carbonic anhydrases is to regulate pH and osmotic balance, their involvement in other physiological processes remains to be explored. This study analysed changes in mRNA and protein levels of carbonic anhydrase II in human primary keratinocytes treated with various toll-like receptor agonists and cytokines. A significant upregulation of carbonic anhydrase II at the mRNA and protein levels was observed upon treatment with polyinosinic-polycytidylic acid, a toll-like receptor 3 agonist. Furthermore, in agreement with the increased expression of carbonic anhydrase II in atopic dermatitis skin, carbonic anhydrase II was upregulated by the Th2 cytokines interleukins -4 and -13. In conclusion, these results suggest a potential role of carbonic anhydrase II in Th2-dependent and toll-like receptor 3-induced pathways in inflammatory skin conditions.