title: Increased expression of netrin-1 and its deleted in colorectal cancer receptor in human diseased lumbar intervertebral disc compared with autopsy control.
abstract: METHODS
  The expression of netrin-1 and its deleted in colorectal cancer (DCC) receptor was investigated in human lumbar discs using immunohistochemistry.
  
  
  OBJECTIVE
  To investigate the expression of netrin-1 and DCC receptor in human diseased and healthy lumbar intervertebral discs (IVDs) and to clarify the correlation between netrin-1 expression and the degree of neurovascular ingrowth.
  
  
  BACKGROUND
  Previous studies have shown neurovascular ingrowth into the inner regions of degenerated IVD and suggested that the ingrowth may contribute to discogenic low back pain. Netrin-1 is an axon guidance molecule that regulates axons seeking their final targets and has been identified as involved in various pathological conditions, so is its DCC receptor. However, the role of netrin-1 in diseased IVDs remains unknown.
  
  
  METHODS
  Thirty-five diseased IVD specimens were collected from 34 patients with different lumbar diseases during posterior lumbar interbody fusion. Eight normal discs were obtained at autopsy as control. Using polyclonal or monoclonal antibody, the disc slides were immmunostained to detect the expression and distribution of netrin-1, the DCC, the neuronal marker (neurofilament), and the vascular endothelial cell marker (CD34).
  
  
  RESULTS
  Netrin-1 and DCC immunopositive cells distributed substantially from the annulus fibrosus to the nucleus pulposus (NP), and the immunopositivity was detected in the disc cells, endothelial cells and granulation tissue cells in the diseased discs. The percentage of netrin-1 positive disc cells of the NP was more than that of the annulus fibrosus. The expression of netrin-1 and DCC was weak in the normal discs. A significant positive correlation between the percentage of netrin-1 immunopositive disc cells and neurovascular scores was found.
  
  
  CONCLUSIONS
  The increased expression of netrin-1 and DCC in diseased IVDs compared with controls suggested that they might play an important role in the process of neurovascular ingrowth.
authors.affiliation: Department of Orthopaedics, Institute of Orthopaedics, First Affiliated Hospital of Chinese People's Liberation Army General Hospital, Beijing, China.
authors.forename: Guoyun
authors.initials: G
authors.lastname: Bu
authors.forename: Shuxun
authors.initials: S
authors.lastname: Hou
authors.forename: Dongfeng
authors.initials: D
authors.lastname: Ren
authors.forename: Ye
authors.initials: Y
authors.lastname: Wu
authors.forename: Weilin
authors.initials: W
authors.lastname: Shang
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018952:Antigens, CD34 / Q000032:analysis; D001344:Autopsy; D015415:Biomarkers / Q000032:analysis; D016022:Case-Control Studies; D000075389:DCC Receptor; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007403:Intervertebral Disc / Q000098:blood supply / Q000737:chemistry* / Q000473:pathology / Q000601:surgery; D008159:Lumbar Vertebrae / Q000098:blood supply / Q000737:chemistry* / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009414:Nerve Growth Factors / Q000032:analysis*; D000075388:Netrin-1; D016900:Neurofilament Proteins / Q000032:analysis; D011956:Receptors, Cell Surface / Q000032:analysis*; D012720:Severity of Illness Index; D013122:Spinal Diseases / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D013123:Spinal Fusion; D025521:Tumor Suppressor Proteins / Q000032:analysis*; D015854:Up-Regulation; D055815:Young Adult
chemical_list: D018952:Antigens, CD34; D015415:Biomarkers; D000075389:DCC Receptor; C501909:DCC protein, human; C000617351:NTN1 protein, human; D009414:Nerve Growth Factors; D016900:Neurofilament Proteins; D011956:Receptors, Cell Surface; D025521:Tumor Suppressor Proteins; D000075388:Netrin-1