Article

Mechanical forces and inflammatory signaling influence intervertebral
disc matrix homeostasis. We hypothesized that annulus fibrosus cells from
degenerative discs would have altered responses to mechanical and inflammatory
stimuli compared with cells isolated from normal discs. DESIGN: Annulus fibrosus
cells were isolated from New Zealand White rabbits with normal and magnetic
resonance imaging-confirmed degenerative discs created by annular stab. Cells
were cultured with and without inflammatory and mechanical stimuli (tensile
strain). After 4 or 24 hrs, the mRNA expression of inflammatory, catabolic, and
anabolic genes was measured by reverse transcription polymerase chain reaction.
RESULTS: Baseline gene expression differences were noted between cells from
normal and degenerative discs. Degenerative cells demonstrated a more
proinflammatory response profile to inflammatory and mechanical stimuli and loss
of the beneficial effects of mechanical signaling. Decreased expression of
catabolic and anabolic genes was observed in degenerative cells under conditions
of inflammatory and mechanical stimuli. CONCLUSIONS: These data demonstrate that
degenerative cells have a decreased capacity to respond positively to beneficial
levels of mechanical strain and demonstrate an exaggerated response to an
inflammatory stimulus. This may, in part, help to explain differential responses
to motion-based therapies in patients with intervertebral disc degeneration.

Langue : ANGLAIS