Expression And Correlation Study Of HMGB1and MMP-9in Cartilage Endplate Of Degenerated Intervertebral Disc

Objective:To investigate the expression of HMGB1and MMP-9in the endplate of Rabbits degenerative intervertebral disc and to explore its correlation and significance.Methods:Animal intervertebral disc degeneration (IDD) model created:Japanese White Rabbits was chose to be the animal models with damaging annulus fibrosus by needle punctured through anterior lateral lumbar approaches.Rabbits were killed at different time points post operation,removed the intact affected discs as the model group, and non-affected lower lumbar discs as the control group.The general organization specimens and HE histological staining was to be used to observe the change of degenerative disc model in the different time points. Qualitative, position detection the positive expression ratio of HMGB1and MMP-9in discs with double mark immunohistochemical staining method. Then acquired data was analysed with SSPS13.0system.Results:1,Results of tissue sections with HE staining showed that:in the control group, cartilage end plate structure was normal. Those in four weeks, intervention intradiscal group were seen that annulus fibrosus structural was disorder and cartilage endplate at the cellular level was unclear and disorganized; the nucleus pulposus of8weeks age group was shrinkage, annulus was fissures, calcification layer of cartilage endplate was thicken, the number of cells was reduced. Disc of12weeks of age group was obviously degenerative, cartilage endplate calcification layer was significantly thicker,ossification structural disorder, cartilage lacuna was disappear.and nucleus pulposus which was adjacent cartilage endplate was significantly degeneration and fibrosis.2,In intervertebral disc endplate of control group, HMGB1had a little expression and MMP-9had no expression or extremely weak expression. It appeared in the cells and no expression in the cell matrix.3,Co-expression of HMGB1and MMP-9in the4weeks model could be seen in some cells. Single expression in cells was rarely seen. Surrounding matrix of positive cells could be seen the scattered expression of HMGB1and MMP-9; Cells that co-expression of HMGB1and MMP-9gradually increased at8weeks,12weeks and appeared in most of the cells. Cells that more HMGB1expression could be seen more MMP-9expression simultaneously, surrounding matrix of positive cells could also be seen the expression of HMGB1and MMP-9.Conclusion:1,By intervertebral disc puncture method, we successfully established rabbit lumber intervertebral disc degeneration model.2,HMGB1expression continues to increase after operation, which is related to aggravation of disc degeneration。3,HMGB1may be one important reason that continuesly increase of MMP9expression, and it closely related to HMGB1's positive feedback regulation.4,The function that HMGB1up-regulate MMP-9may be closely related to disc degeneration.