Expression And Significance Of IL-1α And MMp-2 In Lumbar Disc Degeneration

ObjectiveBy comparing the amount of interleukin -1α(IL-1α) and matrix metaloproteinases-2(MMP2) in normal and degenerative lumbar intervertebral disc, we analyzedthe expression changes of these two proteins in the progression of lumbar disc disorders, and studied the relationship between their expression level and the degree of lumbar discdegeneration.MethodsAll samples were from patients in The First Hospital of China Medical Universityfrom May, 2004 to December, 2006. The surgical treatments were performed by the samegroup of doctors. According to MRI and conditions during the surgery, 22 cases withprotrusion were divided into group A, and 20 cases into group B with sequestrationphenotype. 10 control samples were the unaffected intervertebral discs from patientssuffering from lumbar vertebral bursting fracture. All samples were rinsed thoroughly in0.9% NaCl to remove blood right after the surgical procedure, and soaped in 10%formalinwithin 3 min. After fixed for 24 hours, samples were embedded in paraffin wax, then sectioned to 5 um thick slices. Immunostaining method was used to detect theexpression level of IL-1αand MMP-2. Since IL-1αand MMP-2 are located in thecytoplasm, the presence of these proteins is correlated with brown grains in the cytosolwhen observed under microscope. 10 fields were randomly selected and the number ofcells was counted. Protein expression level was showed as the percentage of positivestaining cells: (-) indicates that there are very little positive staining cells, less than 5%; (+)indicates that there are some positive staining cells, less than 20%; (++) indicates that there are many positive staining cells, more than 20%. The data was analyzed with statisticalsoftware SPSS11.5 for X~2 test, P＜0.05 means the data is statistically significant.ResultThe positive staining cells (chonrocytes and fibroblasts) spread evenly in the tissue, with brown in the cytoplasm. The expression level of IL-1αand MMP-2 is much higher ingroup A and B than in the control group. The expression of IL-1αshows no significantdifference between group A (86.36%) and B(85%), while the expression of MMP-2 ishigher in group B (63. 63% in group 13 vs 90% in group A)ConclusionThe expression levels of IL-1αand MMP-2 are higher in degenerative lumbarintervertebral disc. The up regulation of MMP-2 probably has something to do with thedegree of intervertebral disc degeneration, while IL-1αseems not related. The increaseingexpression of IL-1αand MMP-2 might be one reason that results in the degeneration andprolapse of lumbar intervertebral discs.