Davut DUMANLIDAĞ, Didem KELEŞ BARTIK, Gülgün OKTAY, Can KOŞAY

Effects of vertebral fusion on levels of pro-inflammatory and catabolic mediators in a rabbit model of intervertebral disc degeneration

Objective: The aim of this study was to explore the alterations in levels of pro-inflammatory and catabolic mediators followingvertebral fusion in a rabbit model of intervertebral disc degeneration.Methods: In this study, 24 female New Zealand albino rabbits (aged 4 to 5 months and weighing 3 to 3.5 kg) were used. All theanimals were randomly categorized into four groups, and dorsal spinal exposure of all lumbar vertebrae was routinely performedin each group. While disc degeneration was created in groups B, C, and D, spinal fusion was added to disc degeneration in groupsC and D. Disc degeneration was typically created by puncturing the discs with an 18-gauge needle under the guidance of C-armimaging. Fusion was achieved with posterior/posterolateral decortication and iliac bone grafts. The rabbits in groups A, B, and Cwere euthanized, and the discs were removed in the first week after the surgery. The rabbits in Group D were sacrificed, and thediscs were harvested at 5 weeks after the surgery. The levels of Interleukin (IL)-1β, IL-6, Nitric Oxide (NO), MatrixMetalloproteinase (MMP)-3, MMP-13, and Tissue Inhibitor of Metalloproteinases-1 (TIMP-1) in the discs were analyzed usingenzyme-linked immunosorbent assay kits.Results: Significant increase was observed in the protein levels of both pro-inflammatory and catabolic mediators in discdegeneration groups (Group B, C, and D) compared to Group A. In the fusion groups (Group C and D), these increasedmediators decreased, compared to non-fusion group (Group B), (IL1-β P = 0.017, TIMP-1 P = 0.03, NO P = 0.03). However,there was no statistically significant difference in mediator levels between the short- and long-term fusion (Group C versus D).Conclusion: The results of this study have shown that a significant decrease in pro-inflammatory and catabolic mediators may beexpected after vertebral fusion whereas there may be no significant difference between the first and fourth week of fusionsurgery. These findings may contribute to clarifying the mechanism of action of vertebral fusion in the treatment of low backpain.

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1. An HS, Thonar EJ, Masuda K. Biological repair of intervertebral disc. Spine (Phila Pa 1976). 2013;28(15):86-92. 10.1097/01.BRS.0000076904.99434.40

2. Burke JG, Watson RW, McCormack D, Dowling FE, Walsh MG, Fitzpatrick JM. Intervertebral discs which cause low back pain secrete high levels of proinflammatory mediators. J Bone Joint Surg Br. 2002;84(2):196-201. 10. 1302/0301-620X.84B2.0840196

3. Hsieh AH, Lotz JC. Prolonged spinal loading induces matrix metalloproteinase-2 activation in intervertebral discs. Spine (Phila Pa 1976). 2003;2816:1781-1788. 10.1097/01.BRS.0000083282.82244.F3.

4. Kang JD, Georgescu HI, McIntyre-Larkin L, Stefanovic-Racic M, Donaldson WF, Evans CH. Herniated lumbar intervertebral discs spontaneously produce matrix metalloproteinases, nitric oxide, interleukin-6, and prostaglandin E2. Spine (Phila Pa 1976). 1996;21(3):271-277. 10.1097/00007632-199602010- 00003

5. Purmessur D, Walter BA, Roughley PJ, Laudier DM, Hecht AC, Iatridis J. A role for TNFα in intervertebral disc degeneration: A non-recoverable catabolic shift. Biochemical and biophysical research communications. 2013;433(1):151-156. 10.1016/j.bbrc.2013.02.034

6. Schroeder M, Viezens L, Schaefer C, et al. Chemokine profile of disc degeneration with acute or chronic pain. J Neurosurg Spine. 2013;18(5):496-503. 10. 3171/2013.1.SPINE12483

7. Kang JD, Stefanovic-Racic M, McIntyre LA, Georgescu HI, Evans CH. Toward a biochemical understanding of human intervertebral disc degeneration and herniation. Contributions of nitric oxide, interleukins, prostaglandin E2, and matrix metalloproteinases. Spine (Phila Pa 1976). 1997;22(10):1065-1073. 10. 1097/00007632-199705150-00003

8. Stetler-Stevenson WG. Tissue inhibitors of metalloproteinases in cell signaling: Metalloproteinase-independent biological activities. Sci Signal. 2008;1(27):re6. 10.1126/scisignal.127re6

9. Kroeber MW, Unglaub F, Wang H, et al. New in vivo animal model to create intervertebral disc degeneration and to investigate the effects of therapeutic strategies to stimulate disc regeneration. Spine. 2003;27(23):2684-2690. 10. 1097/00007632-200212010-00007

10. Kwon YJ. Resveratrol has anabolic effects on disc degeneration in a rabbit model. J Korean Med Sci. 2013;28(6):939-945. 10.3346/jkms.2013.28.6.939

11. Gruber HE, Hanley ENJr. Analysis of aging and degeneration of the human intervertebral disc. Comparison of surgical specimens with normal controls. Spine (Phila Pa 1976). 1998;23(7):751-757. 10.1097/00007632-199804010- 00001

12. van Tulder MW, Koes B, Seitsalo S, Malmivaara A. Outcome of invasive treatment modalities on back pain and sciatica: An evidence-based review. Eur Spine J. 2006;15(Suppl 1):82-92. 10.1007/s00586-005-1049-5

13. Boden SD, Schimandle JH, Hutton WC. An experimental lumbar intertransverse process spinal fusion model. Radiographic, histologic, and biomechanical healing characteristics. Spine (Phila Pa 1976). 1995;20(4):412-420. 10.1097/ 00007632-199502001-00003

14. Riordan AM, Rangarajan R, Balts JW, Hsu WK, Anderson PA. Reliability of the rabbit postero-lateral spinal fusion model: A meta-analysis. J Orthop Res. 2013;31(8):1261-1269. 10.1002/jor.22359

15. Kepler CK, Markova DZ, Dibra F, et al. Expression and relationship of proinflammatory chemokine RANTES/CCL5 and cytokine IL-1β in painful human intervertebral discs. Spine (Phila Pa 1976). 2013;38(11):873-880. 10.1097/BRS. 0b013e318285ae08

16. Valdes M, Palumbo M, Appel AJ, McAllister S, Ehrlich M. Posterolateral intertransverse lumbar arthrodesis in the New Zealand White rabbitmodel: II. Operative technique. Spine J. 2004;4(3):293-299. 10.1016/j.spinee.2003.08.022

17. Singh K, Masuda K, An HS. Animal models for human disc degeneration. Spine J. 2005;5(6 Suppl):267-279. 10.1016/j.spinee.2005.02.016

18. Masuda K, Aota Y, Muehleman C, et al. A novel rabbit model of mild, reproducible disc degeneration by an anulus needle puncture: Correlation between the degree of disc injury and radiological and histological appearances of disc degeneration. Spine (Phila Pa 1976). 2005;30:5-14. 10.1097/01.brs.0000148152.04401.20

19. Miyagi M, Ishikawa T, Kamoda H, et al. ISSLS prize winner: Disc dynamic compression in rats produces long-lasting increases in inflammatory mediators in discs and induces long-lasting nerve injury and regeneration of the afferent fibers innervating discs: A pathomechanism for chronic discogenic low back pain. Spine (Phila Pa 1976). 2012;37(21):1810-1818. 10.1097/BRS. 0b013e31824ffac6

20. Kepler CK, Anderson DG, Tannoury C, Ponnappan RK. Intervertebral disk degeneration and emerging biologic treatments. J Am Acad Orthop Surg. 2011;19(9):543-553. 10.5435/00124635-201109000-00005

21. Le Maitre CL, Freemont AJ, Hoyland JA. Localization of degradative enzymes and their inhibitors in the degenerate human intervertebral disc. J Pathol. 2004;204(1):47-54. 10.1002/path.1608

22. Roberts S, Caterson B, Menage J, Evans EH, Jaffray DC, Eisenstein SM. Matrix metalloproteinases and aggrecanase: Their role in disorders of the human intervertebral disc. Spine (Phila Pa 1976). 2000;25(23):3005-3013. 10.1097/ 00007632-200012010-00007

23. Bachmeier BE, Nerlich A, Mittermaier N, et al. Matrix metalloproteinase expression levels suggest distinct enzyme roles during lumbar disc herniation and degeneration. Eur Spine J. 2009;18(11):1573-1586. 10.1007/s00586-009-1031-8

24. Zhang F, Zhao X, Shen H, Zhang C. Molecular mechanisms of cell death in intervertebral disc degeneration (review). Int J Mol Med. 2016;37(6):1439-1448. 10.3892/ijmm.2016.2573