Expression and clinical significance of bone morphogenetic protein-2,typeII collagen in the nucleus pulposus tissue of human degenerated lumbar intervertebral discs

Objective:To investigate the expression and clinical significance of bone morphogenetic protein-2(BMP-2),type Ⅱ collagen in nucleus pulposus of human degenerated lumbar intervertebral discs.Method:The mRNA and protein expression of BMP-2,type Ⅱ collagen in the experimental group(30 fresh nucleus pulposus of patients with lumbar disc herniation,23 male and 7 female) and control group(8 fresh nucleus pulposus of patients with traumatic lumbar vertebrae,6 male and 2 female) were detected with in situ hybridization and immunohistochemical techniques.The determination index was the average gray scale.The statistical methods were based on two-sample t-test and linear correlation.Result:There was stronger expression of mRNA and protein of BMP-2 in the experimental group (109.51±8.32,104.48±14.24) than that in the control group(146.93±16.35,146.38±19.53;P0.05,P0.01).On the contrary,there was stronger expression of type Ⅱ collagen in the control group(113.09±15.28,113.72±13.59) than that in the experimental group (139.49±16.05,140.34±18.26;P0.01,P0.01).There was certain negative correlation between the expression of mRNA and protein of BMP-2 and that of type Ⅱ collagen in the experimental group(r=-0.602,-0.614;P0.01,P0.01).Conclusion:BMP-2 may be an important regulatory factor in intervertebral disc degeneration.The regulatory function of BMP-2 in the process of intervertebral disc degeneration has certain relationship with type Ⅱ collagen of intervertebral disc.The increasing expression of BMP-2 in intervertebral disc may be a protective reaction to intervertebral disc degeneration.