Expression of monocyte chemoattractant protein‐1 in primary cultures of rabbit intervertebral disc cells

Abstract

Macrophages are considered essential for herniated disc resorption, and chemokines may play a role in their recruitment. Here we demonstrate that intervertebral disc cells are capable of producing monocyte chemoattractant protein-1 (MCP-I), a CC chemokine that is chemotactic for macrophages. Nucleus pulposus cells and anulus fibrosus cells were harvested from intervertebral discs of healthy rabbits, and the cells were stimulated with either interleukin (IL)-lp or tumor necrosis factor (TNF)c(. Reverse transcriptase polymerase chain reaction demonstrated that IL-1 p and TNFa induced mRNA expression for MCP-I in nucleus pulposus and anulus fibrosus cells. Protein concentrations of MCP-1 in the culture supernatants were quantitated by fluoroimmunoassay, which showed that nucleus pulposus and anulus fibrosus cells dose-and time-dependently produced MCP-1 after IL-1 band TNFcc-stimulation, an event that was completely abrogated by 1L-1 receptor antagonist and anti-TNFct monoclonal antibody, respectively. Nucleus pulposiis cells produced significantly higher levels of MCP-1 than did anulus fibrosus cells. Immunohistochemically, the intensity of MCP-1 positive cells in nucleus pulposus cells was stronger than that in anulus fibrosus cells. Altogether, our data clearly demonstrated the production of MCP-1 in intervertebral disc cells, suggesting the possible involvement of disc cells in an early stage of macrophage infiltration.

Tumor necrosis factor-α: a key contributor to intervertebral disc degeneration

“…In addition to these chemokines, stimulation of human AF cells with TNF-α exhibits a significant increase in the levels of CCL2, also known as monocyte chemoattractant protein-1 [96]. This is also demonstrated in rabbit AF and NP cells [97]. Taken together, these studies suggest that TNF-α acts as a key player in amplifying inflammation during disk degeneration.…”

Tumor Necrosis Factorα Modulates Matrix Production and Catabolism in Nucleus Pulposus Tissue

“…Furthermore, the up-regulated production of MCP-1 in NP cells following TNF␣ stimulation has suggested that TNF␣ may also contribute to the resorption of the herniated disc through the promotion of macrophage infiltration. 42 Immunohistochemical localization studies in degenerate IVDs have shown the presence of MMPs and, thus, their potential involvement in matrix remodeling and degradation. The current study shows increased gene expression of MMP-1 and MMP-13 following exposure to levels as low as 1 ng/mL TNF␣.…”

Emerging Technologies for Molecular Therapy for Intervertebral Disk Degeneration

“…41 IL-1 induced the production of collagenase, 45 cycloxygenase-2 (COX-2 46 ), prostaglandin E2, 13,47 nitric oxide, 45,44 MMP-1, 48 total 46 and active 43 MMP-3, MMP-13, 20,44 the aggrecanase, a disintegrin and metalloproteinase with t hrombo s pondin motifs-4 (ADAMTS-4), 21,44 IL-6, 46 and monocyte chemoattractant protein-1 (MCP-1). 49,50 Recently, IL-1β was shown to increase the sensitivity of IVD cells to shear stress, 51 suggesting that this cytokine is involved in the acceleration of degradation processes in IVDs subjected to biomechanical stress. Although IL-1 affects both synthetic and degradative processes, it is worth noting that, at lower concentrations, IL-1 was much more effective in inhibiting the synthesis of aggrecan than in stimulating its degradation in articular cartilage.…”