In vitro and in vivo analysis of a JAK inhibitor in rheumatoid arthritis

Multiple cytokines play a pivotal role in the pathogenesis of rheumatoid arthritis (RA). The appropriate intracellular signalling pathways must be activated via cytokine receptors on the cell surface, and the tyrosine kinases transduce the first ‘outside to in’ signals to be phosphorylated after receptor binding to its ligand. Among them, members of the Janus kinase (JAK) family are essential for the signalling pathways of various cytokines and...