TNF is required for the induction but not the maintenance of compression-induced BME signals in murine tail vertebrae: limitations of anti-TNF therapy for degenerative disc disease

J Orthop Res. 2011 Sep;29(9):1367-74. doi: 10.1002/jor.21370. Epub 2011 Mar 28.

Abstract

While bone marrow edema (BME) is diagnostic of spondyloarthropathy, its nature remains poorly understood. In contrast, BME in ankylosing spondylitis is caused by tumor necrosis factor (TNF)-induced vascular and cellular changes. To investigate the relationship between chronic compression and TNF signaling in compression-induced BME we utilized a tail vertebrae compression model with WT, TNF-Tg, and TNFR1&2-/- mice to evaluate: (i) healing following release of chronic compression, (ii) induction of BME in the absence of TNFR, and (iii) efficacy of anti-TNF therapy. Compression-induced normalized marrow contrast enhancement (NMCE) in WT was significantly decreased threefold (p < 0.01) within 2 weeks of release, while the NMCE values in TNF-Tg vertebrae remained elevated, but had a significant decrease (p < 0.05) by 6 weeks after the release of compression. TNFR1&2-/- mice were resistant to compression-induced BME. Anti-TNF therapy did not affect NMCE versus placebo. Histological examination revealed that NMCE values significantly correlated with marrow vascularity and cellularity (p < 0.05), which account for 76% of the variability of NMCE. Collectively, these data demonstrate a critical role for TNF in the induction of chronic compression-induced BME, but not in its maintenance. Amelioration of BME is achieved through biomechanical stability, but is not affected by anti-TNF therapy.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal / pharmacology
  • Bone Marrow / metabolism*
  • Bone Marrow / pathology
  • Chronic Disease
  • Disease Models, Animal
  • Edema / metabolism*
  • Edema / pathology
  • Female
  • Intervertebral Disc Degeneration / drug therapy
  • Intervertebral Disc Degeneration / metabolism*
  • Magnetic Resonance Imaging
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Recovery of Function
  • Spine / metabolism*
  • Spine / pathology
  • Spine / physiopathology
  • Stress, Mechanical
  • Tail
  • Tumor Necrosis Factor-alpha / antagonists & inhibitors*
  • Tumor Necrosis Factor-alpha / immunology
  • Tumor Necrosis Factor-alpha / metabolism*

Substances

  • Antibodies, Monoclonal
  • Tumor Necrosis Factor-alpha