Hyaluronan inhibits TLR-4 dependent cathepsin K and matrix metalloproteinase 1 expression in human fibroblasts

► Cathepsin K expression is enhanced by LPS stimulation via a TLR-4 pathway. ► HA inhibits LPS-induced expression of cathepsin K and MMP-1. ► Inhibition of cathepsin K expression depends on CD44 but not ICAM-1 interaction. ► Inhibition of MMP-1 expression is mediated by both CD44 and ICAM-1 interaction. ► Intra-articular HA administration has protective effects, useful in RA treatment.