An Associative Study Of The Expression Of Trail And Trail-r2(dr5) In The Pulpy Nucleus Tissue Of Human Cervica Disc And The Apoptosis Of Nuclei Pulposus.

Objective: To determine the cell density, apoptosis rate and the expressions of TRAIL and DR5 in human cervical intervertebral discs. In order to further explore the ways of DR5/TRAIL apoptosis in human cervical intervertebral disc nucleus pulposus and the relationship to apoptosis, and to analyze the interrelationship of the various indicators. so as to further understand the mechanism of human cervical intervertebral disc degeneration and provide a new idea for biologic treatment of it in future.METHODS: The control group consisted of 30 human traumatic normal cervical intervertebral discs(C3-C7)and 30 human degenerative cervical intervertebral discs in experimental group(C3-C7)were surgically collected from patients undergoing anterior cervical discectomy and fusion(ACDF). All the cases were affirmed by Pathology. Apoptotic bodies and the cell density were detected by HE staining; Apoptotic disc cells were detected by TdT - mediated dUTP– biotin nick end labeling (TUNEL) and histomorphology, and immunohistochemical staining method was performed to examine the expressions of TRAIL and DR5 in all specimens. All the data were analyzed with SPSS12.0 statistical software. P<0.05 was considered the level of significance.RESULTS: The cell density was lower in patient group(6.52±0.94个/HP) than in control group(9.50±1.33个/HP). The positivity rate of TUNEL staining was higher in patient group(10.93%±1.87%) than in control group(6.43%±1.56%). The positive expression rate of TRAIL and DR5 of nucleus pulposus in patient group(49.13±15.66%,50.73±15.92%) was higher than that in control group(20.26±2.81%,41.23±16.35%) (P < 0. 05). When the total 60 specimens in the two groups were analyzed, TUNEL positive incidence showed significant inverse correlations with their respectively corresponding cell densities (r =﹣0.969, P < 0.01). The TRAIL and DR5 positive incidence of nucleus pulposus showed significant positive correlation with the TUNEL positive incidence of nucleus pulposus (r = 0.921, r =0.755, P < 0.01).CONCLUSION: The cell density decrease plays certain roles in the intervertebral disc degeneration progress of humans.Cell apoptosis explains the decrease of nucleus pulposus to some extent. The apoptosis pathway induced by DR5/ tumor necrotic factor-related apoptosis-inducing ligand ( TRAIL) maybe exists in C ID tissues, indicating that these two genes may be the potential target genes to slow down human cervical disc degeneration by inhibiting disc cells,apoptosis in future.