The Experiment Research Of Relationship Between Apoptosis And Expression Of NF-κB In The Endplate Of Degenerative Intervertebral Disc

Objective:To study the rule of apoptosis of cartilage endplate in degenerative intervertebral disc model and its relationship with nf-kB expression.Methods:36the Japanese big ear rabbit, aged three months,were randomly divided into three groups which4weeks group、8weeks group、12weeks group.16epidural needles acupuncture needle was used to core the intervertebral disc of L2-3、L3-4and L4-5to induce disc degenerative model, The disc of L1-2、L5-6which exposure without piercing as self-control in each animal; The rabbits were killed at4weeks,8weeks,12weeks after model was set up, the thoracic vertebral and Lumbar vertebral spine were completely taken out and observed with the naked eye and taken Photograph, then complete disc of intervention group and control group including a small amount of the cancellous bone attach to cartilage endplate) were taken out to observe the apoptosis cells and expression of NF-KB in cartilage endplate with HE dyeing、TUNEL dyeing、TUNEL dyeing and immunohistochemistry double staining.Results:1. General observation:acupuncture hole could be seen in those at four weeks sample and the color, texture, thickness of disc did not change, no obvious vertebral osteophyte was formed. At8weeks group, acupuncture hole disappeared, disc color got more gray, texture got harder, disc got thinner, the outer annulus fibrosus was wrapped by some proliferation of fibrous tissue with vertebral osteophyte formation. At12weeks, disc got thinner, the outer annulus fibrosus was wrapped by apparent proliferation of fibrous tissue, and no obvious degeneration was observed in intervertebral disc tissue of the control group.2. HE staining results:Compared with the control group, the intervertebral disc of experimental group4weeks could be see annulus fibrosus structure disorder, cartilage endplate cellular level was not clear, disordered arrangement; The annulus fibrosus was disorder, nucleus pulposus matrix disintegration and nucleus pulposus cells decreased at8weeks; At12weeks annulus fibrosus appeared disorder and rupture, rendering hyaline degeneration.3. TUNEL staining results:A small amount of apoptosis cells could be seen in cartilage endplate of intervertebral disc and annulus fibrosus of control group, with the time passed, apoptosis cells increased slightly; For the experimental group at8weeks, dyeing cells apoptosis expression in the cartilage endplate and annulus fibrosus were significantly increased compared with the control group at the same time, with the passage of time, Dyeing cells apoptosis expression increased in the cartilage endplate and in annulus fibrosus of intervertebral disc in experimental group4. Results of TUNEL staining and immunohistochemical double staining of NF-κB: Stained apoptotic cells and NF-κB had little expression in intervertebral disc endplate in the control group, cell that co-expressing apoptosis staining and NF-κB factor in one cell was occasionally seen; At4weeks, NF-κB expression in the the endplate of intervertebral disc could be observed in more cells, whereas apoptotic stain cells got less with spotty distribution, and factor NF-κB and staining apoptotic co-expressed in one apoptotic cell could find. At8weeks, stained apoptotic cells increased and NF-κB expression decreased whereas apoptotic cell with apoptosis staining and NF-κB factors co-expressed increased, showing spotty distribution; At12weeks, stained apoptotic cells further increased and in its surrounding with scattered NF-κB expression, expression of NF-κB apoptosis cells decreased, co-expressed cell got reduced compared to that at eight weeks.Conclusion: 1. With the process of degeneration of intervertebral disc, the number of apoptotic cells in cartilage endplate and annulus expression were significantly increased, suggesting that apoptosis may play an important role in the process of intervertebral disc degeneration.2. Clustering of apoptotic cells and those cells which express NF-κB were observed in the process of degeneration of disc, suggesting that that NF-κB may be a direct factor in the early start of apoptosis, and8weeks later the expression of MMPs and inflammatory cytokines induced by NF-κB are important reasons to maintain apoptosis.