Endoplasmic reticulum stress affected chondrocyte apoptosis in femoral head necrosis induced by glucocorticoid in broilers

In our previous study, chondrocyte apoptosis in femoral head necrosis (FHN)-affected broilers was found to be associated with the endoplasmic reticulum stress (ERS) signaling pathway. In the present study, we further explored the role of ERS-induced chondrocyte apoptosis in FHN-affected broilers and the parallel test was carried out with articular chondrocytes cultivated in vitro. The broilers and chondrocytes were treated with methylprednisolone (MP). The main pathological changes in FHN-affected broilers included the proximal femoral head separated from its articular cartilage and growth plate lesions. MP-treated chondrocytes demonstrated morphology changes, cell viability reduction, secretory capacity dysfunction, and apoptosis. The mRNA expressions of pro-apoptotic genes controlled by ERS signaling pathway were up-regulated both in vivo and in vitro experiments. It showed that MP induced FHN in broilers, activated apoptosis-related genes on ERS signaling pathway, and affected the survival and apoptosis of chondrocytes, and bone growth.