Expression of Fas receptor and apoptosis in vertebral endplates with degenerative disc diseases categorized as Modic type I or II

Study design

Vertebral endplate tissues were obtained from patients with degenerated lumbar disc classified as Modic type 1 or type 2 and investigated with immunohistochemical staining and the DNA nick end labelling techniques.

Objective

To examine the expression of fas receptor (FasR) and apoptosis in the endplate cells isolated from patients with degenerative disc disease and to see whether they are associated with the pathological change of endplate.

Methods

Fifty-six degenerated lumbar endplate specimens were obtained from the patients with degenerative disc disease categorized as type Modic I or II in magnetic resonance imaging (MRI) and eight nondegenerated specimens as control (vertebra burst fracture patients without degenerative change in MRI) during surgical procedures. Immunohistochemical staining was performed to determine the presence of FasR and apoptosis in sections of those endplate tissues. To investigate whether the FasR expression and apoptosis in endplate were influenced by degeneration and ageing of the discs, the level of FasR expression and apoptosis in the changed and unchanged endplates was analysed.

Results

FasR were expressed in the cytoplasm of the endplate cells. A higher degree of FasR expression and apoptosis in endplate cells in degenerated discs was found than that in nondegenerated discs. In cell culture, the level of FasR expression and apoptosis in cells from the degenerative endplates was higher than those in unchanged endplates. The percentage of FasR-positive endplate and apoptotic endplate cells correlated significantly with the patient's age (r = 0.301, p < 0.05; r = 0.307, p < 0.05. respectively), but not with the degree of disc degeneration in MRI (r = 0.047, p > 0.05; r = 0.066, p > 0.05, respectively).

Conclusion

This is the first study to compare the expression of FasR and apoptosis on vertebral endplate cells in degenerated disc with in nondegenerated disc. The results show that the endplate in degenerated disc may undergo fas-mediated apoptosis and vice versa, endplate degenerative changes may promotes apoptosis of the endplate cells within degenerated disc.