Blocking Jak/STAT signalling using tofacitinib inhibits angiogenesis in experimental arthritis

Abstract Objective During rheumatoid arthritis (RA), the angiogenic processes, occurring with pannus-formation, may be a therapeutic target. JAK/STAT-pathway may play a role and the aim of this work was to investigate the inhibiting role of a JAK-inhibitor, tofacitinib, on the angiogenic mechanisms occurring during RA. Methods After ethical approval, JAK-1, JAK-3, STAT-1, STAT-3 and VEGF expression was evaluated on RA-synovial-tissues. In vitro, endothelial cells (ECs), stimulated with 20 ng/ml of VEGF and/or 1 μM of tofacitinib, were assessed for tube formation, migration and proliferation, by Matrigel, Boyden chamber assay and ki67 gene-expression. In vivo, 32 mice received collagen (coll…