Propionibacterium acnes Incubation in the Discs Can Result in Time-Dependent Modic Changes: A Long-Term Rabbit Model. Issue 21 (1st November 2017)

• Record Type: Journal Article
• Authors: Shan, Zhi; Zhang, Xuyang; Li, Shengyun; Yu, Tianming; Liu, Junhui; Zhao, Fengdong
• Is Part Of: Spine. Volume 42:Issue 21(2017)
• Publication Date: 2017-11-01
• Subjects: animal model -- intervertebral disc degeneration -- magnetic resonance image -- Modic changes -- Propionibacterium acne; Spine -- Abnormalities -- Periodicals; Spine -- Diseases -- Periodicals; Spine -- Surgery -- Periodicals; 616.73005
• DOI: 10.1097/BRS.0000000000002192
• Languages: English
• ISSNs: 0362-2436

Abstract

Abstract : Study Design: A case-control study of animal model of Modic changes (MCs) on rabbits. Objective: To evaluate the feasibility of inducing of MCs by injection of Propionibacterium acne ( P. acnes ) into the lumbar intervertebral discs of rabbits. Summary of Background Data: MCs have been widely observed, and assume to be closely associated with low back pain and P. acnes, but there are few animal models showing the progression of MCs. Methods: Ten rabbits were used for the study. The L3–4 and L4–5 discs of all rabbits were injected with 100 μL P. acnes (1.6 × 10 7 CFU/mL) as P. acnes group, L2–3 disc were injected with 100 μL normal saline as vehicle, and L5–6 disc was untreated (blank). MCs were investigated by magnetic resonance imaging before operation and at 2 weeks, 1, 3, 4.5, 6, and 9 months postoperatively. Following sacrifice, histological analysis, blood test and micro-computed tomography were performed. Cytokine expression in nucleus and endplate tissues was quantified using real-time polymerase chain reaction. Results: From 3 months postoperatively, the P. acnes group showed significantly decreased T1-weighted signal intensity, whereas the T2-weighted signal was significantly higher at 3 and 4.5 months, and then decreased remarkably at 6 and 9 months. Eleven of 20 inferior endplates were identified as type I MCs at 4.5 months, and 9 of 20 were identified as type II MCs at 9 months. Real-time polymerase chain reaction showed that expression of interleukin-1β, tumor necrosis factor α, interferon-γ, matrix metalloproteinase-9, and thrombospondin motifs-5 in the nucleus pulposus, and interleukin-1β, tumor necrosis factor α, and thrombospondin motifs-5 in the endplates, were significantly upregulated after injection of P. acnes . Histological slices of discs injected with P. acnes showed disc degeneration, endplate abnormalities, and inflammatory response, with micro-computed tomography confirming bone resorption. Conclusion: P. acnes infection of the disc can induce degeneration of the disc and an inflammatory response in the endplate region, presenting as MCs type I and II time dependently. Level of Evidence: N/A