Title: 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.

Authors: Papuga, M Owen; Kwok, Edmund; You, Zhigang; Rubery, Paul T; Dougherty, Paul E; Pryhuber, Gloria; Beck, Christopher A; Hilton, Matthew J; Awad, Hani A; Schwarz, Edward M

Published In J Orthop Res, (2011 Sep)

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.

PubMed ID: 21445993

MeSH Terms: No MeSH terms associated with this publication