Indian hedgehog contributes to human cartilage endplate degeneration.

OBJECTIVE

To determine the role of Indian hedgehog (Ihh) signaling in human cartilage endplate (CEP) degeneration.

METHODS

CEP-degenerated tissues from patients with Modic I or II changes (n = 9 and 45, respectively) and normal tissues from vertebral burst fracture patients (n = 17) were collected. Specimens were either cut into slices for organ culture ex vivo or digested to isolate chondrocytes for cell culture in vitro. Ihh expression and the effect of Ihh on cartilage degeneration were determined by investigating degeneration markers in this study.

RESULTS

Ihh expression and cartilage degeneration markers significantly increased in the Modic I and II groups. The expression of cartilage degeneration markers was positively correlated with degeneration severity. Gain-of-function for Ihh promoted expression of cartilage degeneration markers in vitro, while loss-of-function for Ihh inhibited their expression both in vitro and ex vivo.

CONCLUSIONS

These findings demonstrated that Ihh promotes CEP degeneration. Blocking Ihh pathway has potential clinical usage for attenuating CEP degeneration.