LIU Jie,PENG Na,LU Yan.Preliminary research for correlation between BNIP3 expression and disc degeneration[J].Chinese Journal of Spine and Spinal Cord,2012,(1):65-71.
Preliminary research for correlation between BNIP3 expression and disc degeneration
Received:July 12, 2011  Revised:August 23, 2011
English Keywords:Disc degeneration  Nucleus pulposus  BNIP3  Rabbit
Fund:
Author NameAffiliation
LIU Jie Department of OrthopaedicsXinqiao Hospitalthe Third Military Medical UniversityChongqing400037China 
PENG Na 第三军医大学新桥医院手术室 400037 重庆市 
LU Yan 解放军187医院骨科 571159 海口市 
王 建  
Hits: 3422
Download times: 2218
English Abstract:
  【Abstract】 Objective:To study the correlation between BNIP3 expression and disc degeneration.Method:Twenty-four one-month white New Zealand rabbits were randomly and equally assigned into four groups:post-surgery for 0 week(n=6),post-surgery for 2 weeks(n=6),post-surgery for 4 weeks(n=6),and post-surgery for 8 weeks(n=6).By puncturing the experimental disc annulus (L4/5,L5/6 and L6/7) with needle,we established a disc degeneration model in New Zealand white rabbit,the normal discs above the experimental discs(L1/2,L2/3 and L3/4) served as control.After the surgery for 0,2,4 and 8 weeks,the disc degeneration,BNIP3 expression and cell morphology were evaluated by using MRI,histochemistry staining,immunohistochemical staining and real-time-PCR,and the correlationship between the BNIP3 expression and the disc degeneration evaluated by MRI and histochemistry was also been analyzed.Result:The MRI showed that the normal discs and discs of post surgery for 0 week exhibited hyperintense in T2 weighting image with the average MRI grade of 1.0±0.0;the discs of post surgery for 2 weeks showed inhomogeneous hyperintense with the average MRI grade of 2.9±0.4;the discs of post surgery for 4 weeks showed intermediate to hypointense with the average MRI grade of 4.2±0.3;the discs of post surgery for 8 weeks showed a hypointense which the average MRI grade of 4.9±0.1.There were significant differences among normal discs and post surgery discs(P<0.05).The histochemistry staining also showed the normal discs and discs of post surgery for 0 week with intact structure and clear border between the annulus fibrosus and nucleus pulposus,the average histological grade was 4.0±0.0;the discs of post surgery for 2 weeks showed slight rupture in annulus fibrosus and minimally interrupted between annulus fibrosus and nucleus pulposus,the average histological grade was 7.5±0.2;the discs of post surgery for 4 weeks showed larger rupture in annulus fibrosus and moderate rupture between annulus fibrosus and nucleus pulposus,the average histological grade was 10.0±1.0;the discs of post surgery for 8 weeks showed the collapse of disc structure and fibrosis of nucleus pulposus,the average histological grade was 11.8±0.2.There were significant differences among normal discs and post surgery discs(P<0.05).The BNIP3 mRNA real-time-PCR of the nucleus pulposus region indicated increased expression of BNIP3 with 1.0±0.3-fold,2.0±0.1-fold,2.8±0.3-fold and 4.2±0.2-fold respectively at 0,2,4 and 8 weeks after surgery,and there was a high correlation between MRI grade and BNIP3 mRNA expression(r=0.92,P<0.01).The BNIP3 immunohistochemical staining of the nucleus pulposus region suggested increased positive reaction with 150.4±13.4,176.0±35.1 and 173.6±7.9 of gray intensity at 2,4 and 8 weeks after surgery,which had a high correlation with histological grade(r=0.92,P<0.01).Conclusion:The expression of BNIP3 mRNA has some relationship with the disc degeneration,and the increased expression of BNIP3 may play an important role in disc degeneration.
View Full Text  View/Add Comment  Download reader
Close