LRP1 and osteoarthritis: Notably, we found in this study that the major proinflammatory factors involved in the inflammatory reactions of the fetal membranes such as IL-1β and SAA1 were capable of inducing ADAMTS4 expression and reducing its endocytosis in amnion fibroblasts, which is in line with previous studies showing that proinflammatory cytokines were capable of inducing ADAMTS expression and LRP1 shedding in osteoarthritis and lung inflammation65,66.