Bone morphogenetic protein 5 (BMP-5) is a pleiotropic ligand protein belonging to the TGFβ family, which is mainly expressed in the lung and liver. After BMP-5 silencing, the activity of p38/ERK signaling pathway can be down-regulated to inhibit chondrocyte senescence and apoptosis and knee arthritis (OA) [1]. Bmp-5 initiates typical BMP signaling cascades by binding to type I receptor BMPR1A and type II receptor BMPR2[2], or triggers signals through atypical pathways such as MAPK p38 signaling cascades to promote chondrogenic differentiation[3].
