PTGES and osteoarthritis: El Mansouri et al. (2014) studied the effect of LSD1 on its own on the expression of mPGES1 (Microsomal prostaglandin E synthase-1) in human joint chondrocytes mPGES1 catalyzes the terminal stage of PGE2 biosynthesis, which mediates the inflammatory response contributing to the development of osteoarthritis.