Fig. 5

Increased calcium influx induces apoptosis by activating the mitochondrial signaling pathway in IL-1β-induced rat chondrocytes. Rat chondrocytes were pre-incubated with the TRPA1 antagonist (HC-030031, 100 μM) or the vehicle for 30 min, and then stimulated with IL-1β (5 or 10 ng/ml) for 24 h. a Caspase-3 and Caspase-9 activity in rat chondrocyte following various treatments. b The Bax, Cyto C, cleaved PARP, cleaved caspase-3 and caspase-9 protein expressions from different stimulated groups were detected by western blotting. The activity detection experiments were carried out in duplicate and the quantitation of protein expression was done by densitometry analysis of the bands from three independent measurements. Values were normalized against GAPDH, and analyzed with ImageJ software. The results are expressed as mean ± SEM. *p < 0.05. IL interleukin, Cyto cytochrome