Figure 1.

The IVDs infected with P. acnes had increased iNOS/NO and COX-2/PGE₂ expressions, concomitant with severe disc degeneration. (a–d) Representative images from lateral X-rays and magnetic resonance imaging point to severe degeneration in P. acnes-positive IVDs (n = 23 for each group). (e–f) Western blot analysis of aggrecan, collagen II, iNOS, and COX-2 in human IVDs. ^∗The P. acnes-positive groups compared with the P. acnes-negative groups. (g, h) The concentration of NO and PGE₂ were tested by the Griess reaction and ELISA, respectively. ^∗The P. acnes-positive groups compared with the P. acnes-negative groups; P < 0.05. P values were analyzed by paired t-test, Student's t-test, and one-way ANOVA. Data are presented as the mean ± SD from three independent experiments.