Abstract: Objective To investigate the expression of DR5 and DcR2 protein and mRNA in lumbar intervertebral disc (LID) of patients with prolapse of LID and normal controls.Methods The expression and distribution of DR5 and DcR2 protein were immunostained in prolapsed LIDs of 60 patients and 22 normal LIDs of 8 normal controls. In parallel, mRNA of DR5 and DcR2 was quantified by real time fluorescent reverse transcriptase-polymerase chain reaction (RT-PCR) in prolapsed LIDs of 30 patients and 9 normal LIDs of 3 normal controls.Results The positive rates of DR5 protein in prolapsed IVDs and normal IVDs were 41.60% and 26.09% respectively. There were a significant difference between the two groups ( P=0.001). Further similar evidences were obtained by quantification of DR5 mRNA ( P=0.025). There was no difference in the expression of DcR2 protein and mRNA between the two groups.Conclusion The apoptosis pathway induced by DR5/tumor necrotic factor-related apoptosis-inducing ligand (TRAIL) maybe exists in LID tissues.

Key words: lumbar vertebrae, intervertebral disc, tumor necrotic factor-related apoptosis-inducing ligand (TRAIL), TRAIL receptor