Ursodeoxycholic acid (UDCA) is used to treat liver diseases and demonstrates cardioprotective effects. Accumulation of the plasma membrane sphingolipid sphingomyelin in the heart can lead to atherosclerosis and coronary artery disease. Sphingomyelinases (SMases) break down sphingomyelin, producing ceramide, and inhibition of SMases activity can promote cell survival. We hypothesized that UDCA regulates activation of ERK and Akt survival signaling pathways and SMases in protecting cardiac cells against hypoxia.
Chondrocytes, which are embedded within the growth-plate or the intervertebral disc, are sensitive to environmental stresses, such as inflammation and hypoxia. However, little is known about the molecular signaling pathways underlying hypoxia-induced mitochondrial dysfunction and apoptosis in chondrocytes. We first examined the apoptosis, caspase-3 activity, and apoptosis-associated markers in human chondrocyte cell line C28/I2 under normoxia or hypoxia.