Proinflammatory intervertebral disc cell and organ culture models induced by tumor necrosis factor alpha.

Jie Du,Gernot Lang,Laura B Creemers,Sonja Häckel,Zhen Li,Sibylle Grad,Mauro Alini,Judith-J Pfannkuche

doi:10.1002/jsp2.1104

Abstract

Inflammation plays an important role in the pathogenesis of intervertebral disc (IVD) degeneration. The proinflammatory cytokine tumor necrosis factor alpha (TNF‐α) has shown markedly higher expression in degenerated human disc tissue compared with healthy controls. Anti‐inflammatory treatment targeting TNF‐α has shown to alleviate discogenic pain in patients with low back pain. Therefore, in vitro and ex vivo inflammatory models utilizing TNF‐α provide relevant experimental conditions for drug development in disc degeneration research.The current method article addressed several specific questions related to the model establishment.(a) The effects of bovine and human recombinant TNF‐α on bovine nucleus pulposus (NP) cells were compared. (b) The required dose for an inflammatory IVD organ culture model with intradiscal TNF‐α injection was studied. (c) The effect of TNF‐α blocking at different stages of inflammation was evaluated.Outcomes revealed that bovine and human recombinant TNF‐α induced equivalent inflammatory effects in bovine NP cells. A bovine whole IVD inflammatory model was established by intradiscal injection of 100 ng TNF‐α/ cm3 disc volume, as indicated by increased nitric oxide, glycosaminoglycan, interleukin 6 (IL‐6), and interleukin 8 (IL‐8) release in culture media, and upregulation of MMP3, ADAMTS4, IL‐8, IL‐6, and cyclooxygenase (COX)‐2 expression in NP tissue. However, results in human NP cells showed that the time point of anti‐inflammatory treatment was crucial to achieve significant effects. Furthermore, anticatabolic therapy in conjunction with TNF‐α inhibition would be required to slow down the pathologic cascade of disc degeneration.

Highlights

Low back pain (LBP) is the leading cause of disability worldwide.[1]
intervertebral disc degeneration (IVDD) is characterized by extracellular matrix (ECM) degradation, accelerated cartilaginous, and bone remodeling, release of proinflammatory cytokines, altered spine biomechanics, angiogenesis and neoinnervation, altogether potentially leading to chronic
Inflammation plays a major role in disc degeneration, as proinflammatory cytokines induce and trigger discal ECM breakdown and accelerated catabolism by stimulation of catabolic enzymes such as matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS).[6,17,18,19,20]

Summary

| INTRODUCTION

Low back pain (LBP) is the leading cause of disability worldwide.[1]. One major cause for chronic LBP is symptomatic intervertebral disc degeneration (IVDD).[2,3,4] IVDD is characterized by extracellular matrix (ECM) degradation, accelerated cartilaginous, and bone remodeling, release of proinflammatory cytokines, altered spine biomechanics, angiogenesis and neoinnervation, altogether potentially leading to chronic. Compared with the small animals like mouse, rat and rabbit, the IVDs from large animals such as sheep, dog and cow are more similar to human They show comparable size and loss of notochordal cells in early adulthood as human IVD.[47,48] Notochordal cells have been reported to present anti-inflammation and regenerative effect in IVDs.[49,50] With those similarities, many bovine caudal IVD organ culture models were established.

| MATERIALS AND METHODS

| RESULTS

| DISCUSSION

Findings

Limitations

| CONCLUSION