Figure 5

Phosphorylation of stress-activated protein kinase/c-Jun N-terminal kinas e (SAP/JNK) and p38 mitogen-activated protein kinase (MAPK) protein in human primary chondrocytes. Human primary chondrocytes were treated with IL-1β treatment (10 ng/mL) for 0 to 120 mintes (A) or pretreated with SP600125 or SB203580 for 30 minutes and then treated with 10 ng/mL IL-1β for 30 minutes (B). Then, phosphorylated and total protein level of SAP/JNK and p38 MAPK, as well as glyceraldehyde-3-phosphate dehydrogenase (GAPDH) protein level, were detected using western blotting assay. IC, IL-1β control, namely chondrocytes treated with 10 ng/mL IL-1β for 30 minutes; ISP, chondrocytes pretreated with SP600125 for 30 minutes and subsequently co-treated with the SP600125 and 10 ng/mL IL-1β for another 30 minutes; ISB, chondrocytes pretreated with SB203580 for 30 minutes and then co-treated with the SB203580 and 10 ng/mL IL-1β for another 30 minutes.