Different Forms of ER Stress in Chondrocytes Result in Short Stature Disorders and Degenerative Cartilage Diseases: New Insights by Cartilage-Specific ERp57 Knockout Mice

Figure 2

Causes and effects of ER stress in growth plate chondrocytes. ER stress in growth plate chondrocytes is induced by mutations in genes encoding ECM components, chaperones, UPR signaling factors, or ERAD proteins. The ER stress-induced unfolded protein response (UPR) substantially impairs essential processes of the endochondral ossification, such as ECM protein synthesis and chondrocyte proliferation and differentiation, and activates autophagy and apoptosis. This results in a chondrodysplasia phenotype with reduced lengths of long bones.