Expression Of IL-9 And TNF-? In Intervertebral Disc With Degeneration And Its Effect On Immune Inflammatory Response In A Rat Model

Objective: To investigate the expression of interleukin-9(IL-9)and tumor necrosis factor-?(TNF-?)in rats with intervertebral disc degeneration and its effect on immune inflammatory response.Methods: Sixty adult SPF healthy male SD rats were selected,with an average age of 6 months and an average body weight of(312.52±22.36)g.Rats were divided into observation group and control group by random number table method,30 in each group.Rats in the observation group were made into intervertebral disc degeneration models with unbalance of dynamic and static forces,meanwhile the rats in the control group underwent sham-operations.Three months after surgery,4-5 intervertebral discs were removed and made into paraffin specimens.Twenty rats were randomly selected from two groups to observe the morphology of the cervical intervertebral disc,and the contents of TNF-? and IL-9 were detected by immunohistochemistry.Five paraffin sections were taken from each specimen.Immunohistochemical SP staining was used to detect the expression of TNF-? and IL-9,and the average optical density(MOD)was calculated.The remaining 10 rats in each group were used for ultrastructural observation of cervical intervertebral disc.Results: In the observation group,the cervical intervertebral disc histological morphology showed that the annular lamellar structure was disordered,the chondrocytes moved to the nucleus pulposus in the form of private soldiers,the collagen fibers were arranged in a network,and part of the nucleus pulposus tissues were wrinkled and the nucleus pulposus cells became smaller.In the observation group,ultrastructure showed cell membrane defects,fingerlike processes on the cell surface decreased or even disappeared,rough endoplasmic reticulum was slightly expanded,the mitochondrial condyle appeared degenerative swelling,disintegration and vacuolization,and heterochromatin edge set appeared in the nucleus.The expression of TNF-? and IL-9 in the observation group was significantly higher than that in the control group;the MOD values of TNF-? and IL-9 in the observation group were significantly higher than those in the control group(P<0.05).Conclusion: The histomorphology and ultrastructural observation of the cervical intervertebral disc in rats shows that the model of cervical intervertebral disc degeneration in rats with dynamic and static imbalance can successfully induce cervical disc degeneration in rats.Immunohistochemical staining shows that both IL-9 and TNF-? are highly expressed in cervical intervertebral disc degeneration,but further studies are needed to investigate whether the two are synergistic or one of them is a trigger of inflammation in vivo.