Relationship Between Protease Activated Receptor 2 And Degeneration Of Lumbar Intervertebral Disc

?Objective?To study the expression of PAR-2 in the nucleus pulposus and annulus fibrosus of human intervertebral disc with different degrees of degeneration,and to analyze the relationship between the expression of PAR-2 and the degree of degeneration of intervertebral disc,and to better help us to understand the pathogenesis of degenerative disease of intervertebral disc.To provide new ideas for the pathophysiological study,diagnosis and treatment of disc degeneration.?Methods?A total of 24 cases of the nucleus pulposus and annulus fibrosus tissue were collected from patients who underwent minimally invasive lumbar vertebrae operations,or anterior or posterior lumbar open surgery.These cases included patients diagnosed as lumbar disc herniation,patients who underwent open incision or minimally invasive intervertebral foramen surgery for the removal of the nucleus pulposus of the lumbar intervertebral disc and lumbar fracture patients whose intervertebral discs needed to be surgically removed.The specimens of nucleus pulposus and annulus fibrosus were evaluated and divided into four groups according to the Pfirrmann method of degenerative classification of intervertebral disc:group A(grade I and II),group B(grade III),group C(grade IV)and group D(grade V)respectively.No obvious degeneration was found in group A.The intervertebral disc tissue was stained with HE method.Immunohistochemical technique was used to analyze the expression of PAR-2 in the nucleus pulposus and annulus fibrosus of intervertebral disc.Positive cells were carefully observed the tissue sections of immunohistochemical staining.According to the methods used by Domestic and foreign scholars,the immunohistochemical results of tissue specimens were analyze,10 high power(400X)visual fields were randomly observed in each section,and the positive rate of PAR-2 immunohistochemical staining(positive cell rate = total positive cell / total cell × 100%)was calculated respectively.The data obtained were analyzed statistically with SPSS18.0 software to further clarify the correlation between PAR-2 and the degree of degeneration of lumbar intervertebral disc.?Results?1?The results of HE staining:(1)in group A,the annulus fibrosus in the lumbar intervertebral disc was clear,the number of cells was less and the distribution was uneven,the nucleus pulposus cells were oval,and the annulus fibrosus cells were fusiform.(2)in group B,C and D,the annulus fibrosus was distorted,the structure was disordered,the number of annulus fibrosus cells was less,and the distribution was not even in group D,and some of the cells were light stained,with the severity of degeneration of lumbar intervertebral disc increased.The shape of the cytoplasm of the nucleus pulposus and annulus fibrosus of the lumbar intervertebral disc is "vacuolated",and the tissue with severe degeneration can also present a large volume of multinucleated chondrocytes.2?Immunohistochemical analysis showed that PAR-2 was expressed in all groups.PAR-2 is mainly expressed in the nucleus.There were weak positive(1),positive(2),moderate positive(3)and strong positive(4)in each group.The corresponding cytoplasm of intervertebral disc were light yellow,light brown yellow,brown yellow and dark brown,respectively.Polynucleation occurs in the cells of the lumbar disc that degenerate severely.With the degenerative degree of intervertebral disc increases,the PAR-2 positive cell rate in nucleus pulposus and fibrous ring increased gradually.There was no significant difference between group A and group B(P > 0.05).There was no significant difference in positive cell rate between group C and group D(P > 0.05).The positive cell rate was significantly higher in group C as compared to group A and group B(P < 0.05).The positive cell rate was significantly higher in group D as compared to group A and group B(P < 0.05).? Conclusion ? 1.PAR-2 expression was found in both degenerative and non-degenerative lumbar intervertebral discs.2.The expression of PAR-2 in degenerative lumbar disc was significantly higher than that in no degenerative lumbar disc.3.The expression of PAR-2 increased progressively with the degeneration of lumbar intervertebral disc.PAR-2 plays an important role in the process of lumbar disc degeneration.