Generating an Organ Culture Model to Simulate Early-Stage Intervertebral Disc Disease

Take an intervertebral disc (IVD), a cushion-like structure located between the vertebrae, from a bovine tail.

Position it vertically and inject recombinant TNF-α, a pro-inflammatory cytokine, into the nucleus pulposus (NP), the gel-like core.

Withdraw the syringe halfway and pull the plunger to create a vacuum, preventing TNF-α backflow. Then, remove the syringe.

Place the IVD in a bioreactor chamber containing media, and apply an intense pressure load daily.

TNF-α binds to its receptors on NP cells, triggering a signaling cascade.

This activates initiator and executioner caspases, which degrade cellular proteins and induce apoptosis.

TNF-α also activates the transcription factor NF-κB, which induces inflammatory gene expression, leading to the release of enzymes that degrade the IVD's extracellular matrix.

Additionally, the intense pressure load induces mechanical stress, further degrading the IVD.

This reduces the IVD's height in comparison to untreated controls, establishing a degenerative and proinflammatory model of early-stage IVD disease.