| Background:as a common musculoskeletal disease,intervertebral disc disease is the primary cause of low back pain in people.At present,its pathogenesis has not been clearly understood.But there is research indicating that Lysyl Oxidase(LOX)may have an effect on repairing intervertebral disc.Therefore,based on this research direction,this paper will continue to study the role of LOX in the intervertebral disc degeneration of rats.Purpose:the intervertebral disc degeneration(IVDD)of rats is prepared by puncturing the intervertebral disc of the tails,and the influence of LOX on the nucleus pulposus(NP)repair of tail intervertebral disc is observed,so as to find out the impact of LOX on IVDD of rats.Methods:first,sixty male adult Sprague-Dawley(SD)rats(around 4 months old)were randomly assigned to the operation group(Group A,n=20),operation+LOX inhibitor group(Group B,n=20)and control group(Group C,n=20).The tail intervertebral discs of rats in group A and B were damaged by puncture needle of No.21 molding,and the tail of rats in group C was only cut open without puncture.The molding process was all marked by X-ray fluoroscopy.and the rats in the group B were injected with LOX inhibitor β-aminopropenitrile(BAPN)every day after the puncture.These rats were killed four weeks after the injury to store the labeled samples.Hematoxylin-eosin staining(HE staining),immunohistochemistry,Western Blot and Polymerase Chain Reaction(PCR)were performed in the processed samples to observe the expression of LOX in the rat intervertebral disc nucleus pulposus.Lastly,the results were analyzed through statistical software SPSS 23.0.Results:1.HE staining:compared with the rats in the group C having more nucleus pulposus cells and matrix,and intact intervertebral disc,those in the group A had looser structure,incompact arrangement of nucleus pulposus cells with loosened and vacuolated cytoplasm,and largely reduced matrix.By comparing with the group A,the matrix of the rats in the group B significantly decreased,local tissue densely shrunk with necrosis,karyolysis and fragmentation.A small number of lymphocytes and neutrophils(NEC)were infiltrated.The nucleus pulposus cells were loosely arranged with loosened cytoplasm or vacuolation.2.Immunohistochemistry:the percentage of LOX and aggrecan positive area in the group A was visibly lower than that in the group C which was lower than that in the control group.the percentage of LOX and aggrecan positive area in the group B was visibly lower than that in the group A which was lower than that in the control group.The percentage of matrix metalloproteinase-3(MMP-3)positive area in group B was significantly higher than that in group A.The percentage of matrix metalloproteinase-3(MMP-3)positive area in group A was significantly higher than that in group C.The positive area ratios of LOX,Aggrecan and MPP-3 among all groups were in line with normal distribution.T-test and one-way analysis of variance were conducted respectively,the differences among all groups have statistical meaning.(P<0.05).In terms of the LOX positive cells,the group A largely decreased than the group C,and the group B also showed an obvious downtrend.Around the expression rate of LOX positive cells,the experimental results of each group were in line with normal distribution.T-test and one-way analysis of variance were conducted respectively,the differences among all groups have statistical meaning.(P<0.05).3.Western Blot:LOX,aggrecan and MMP-3 were expressed in the group A,group B and group C.Compared with group C and group A,the expression levels of Aggrecan and LOX were both low in group A,while the expression levels of MPP-3 were high in group A.Compared with group B,the expression of LOX and Aggrecan in group A were significantly higher than that in group B,while the expression of MPP-3 in group A was significantly lower than that in group B.The differences in the expression levels of LOX,Aggrecan and MPP-3 among groups A,B and C were all in line with normal distribution.T-test and one-way analysis of variance were conducted respectively,the differences among all groups have statistical meaning.(P<0.05).4.PCR:the mRNAs of LOX,Aggrecan and MMP-3 performed in the group A,group B and group C.Compared with the group C,the performance in the group A declined in LOX-mRNA and Aggrecan-mRNA but had an increase in MMP-3-mRNA.When compared to the group B,the expression of LOX-mRNA and aggrecan-mRNA in the group A rose while MMP-3-mRNA expression declined.The differences in the expression levels of LOX-mRNA,Aggrecan-mRNA and MMP-3-mRNA among groups A,B and C were all in line with normal distribution.T-test and one-way analysis of variance were conducted respectively,the differences among all groups have statistical meaning.(P<0.05).Conclusion:the expression level of LOX greatly affected the IVDD of rat tail.When the level is normal,the NP of rat tail intervertebral disc degenerated slightly,which degenerated seriously when the expression was inhibited.It was concluded that LOX affects the formation and progression of NP degeneration in rat intervertebral disc.That means that LOX may have a certain repair effect on nucleus pulposus,but the specific mechanism needs to be further explored and studied. |
