Can TRIF/TICAM-1 Dependent Pathway be Target Pathway in Lumbar Intervertebral Disc Degeneration?

Abstract

The current study aims to elucidate the role of the TIR-domain-containing adaptor-inducing interferon-β (TRIF) dependent pathway in intervertebral disc degeneration (IVD). 88 adult male patients with low back pain (LBP) (+/- radicular pain) were further evaluated by magnetic resonance imaging (MRI) with surgical indication for microscopic lumbar disc herniation (LDH). Preoperatively, patients were classified according to Modic Changes (MC), use of nonsteroidal anti-inflammatory drugs (NSAIDs), and the presence of radicular pain additional to the LBP. The age of the 88 patients ranged from 19 to 75 years (mean: 47.3 ± 19.6 years). 28 of the patients were evaluated as MC I (31.8%), 40 as MC II (45.4%), and 20 as MC III (22.7%). The majority of patients (81.8%) had radicular LBP, while 16 patients (18.1%) had only LBP. Predominantly, 55.6% of all patients were taking NSAIDs. Levels of all adaptor molecules were highest in the MC I group and lowest in the MC III group. The levels of IRF3, TICAM1, TICAM2, NF-kB p65, TRAF6, and TLR4 were significantly increased in the MC I group compared to the MC II and MC III groups. The variations of the individual adaptor molecules showed no statistically significant difference in the use of NSAIDs and radicular LBP. As a result of the impact assessment, the current study clearly demonstrated for the first time that the TRIF-dependent signalling pathway plays a crucial role in the degeneration process in human lumbar intervertebral disc specimens.