Stimulation of IL-6 production in IVD cells. Human intervertebral disc (IVD) cells were incubated for 18 hours with either: hyaluronic acid fragments (fHAs) (20 μg/ml) (n = 4) (A); Pam3CSK4 (25 ng/ml) (n = 4) (B); lipopolysaccharide (LPS) (25 ng/ml) (n = 5) (C); or interleukin (IL)-1β (5 ng/ml) (n = 5) (D), and IL-6 protein levels determined in supernatants using a specific ELISA. In all cases, analyses were performed in triplicate and values expressed as mean ± S.D. Statistical analysis was performed using the Student's t-test, * P <0.05, ** P <0.01 as compared to untreated IVD cells.
Quero et al. Arthritis Research & Therapy 2013 15:R94 doi:10.1186/ar4274