title: [Over-expression of platelet-derived growth factor-BB in degenerative hypertrophied ligamentum flavum].
abstract: OBJECTIVE
  To investigate the role of platelet-derived growth factor-BB (PDGF-BB) in the degeneration of the hypertrophied ligamentum flavum (LF) in the lumbar spine.
  
  
  METHODS
  Surgical specimens of degenerative hypertrophied LF were obtained from 11 patients with lumbar spinal stenosis (LSS, mean age 57.8 years), with those from 10 age-matched patients with lumbar disc herniation (LDH, mean age 53.5 years) as the normal controls. The thickness of the LF was measured preoperatively by axial T1-weighted magnetic resonance imaging (MRI) at the facet joint level. Immunohistochemistry was employed to determine the expression of PDGF β and PDGF-BB in the LF. The mRNA and protein expressions of PDGF-BB in the LF were detected using real-time PCR and Western blotting, respectively.
  
  
  RESULTS
  The thickness of the LF was 5.30±1.12 mm in the degenerative group and 2.80±1.53 mm in the control group, showing a significant difference between the two groups (P<0.001). PDGF-β and PDGF-BB were positive in the fibroblasts in hypertrophied LF. The mRNA and protein expressions of PDGF-BB were significantly higher in the degenerative group than in the control group (P=0.013 and 0.023, respectively).
  
  
  CONCLUSIONS
  The high expression of PDGF-BB in the hypertrophied LF suggests its important role in the development of hypertrophy of LF in lumbar spinal canal stenosis.
authors.affiliation: Department of Orthopedics and Spinal Surgery, Guangdong Second Provincial Hospital of Traditional Chinese Medicine, Guangzhou 510095, China. zhangyu020@126.com
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xue-meng
authors.initials: XM
authors.lastname: Xu
authors.forename: Shao-peng
authors.initials: SP
authors.lastname: Wu
authors.forename: Xiong-zhi
authors.initials: XZ
authors.lastname: Xia
authors.forename: Can-tian
authors.initials: CT
authors.lastname: Li
authors.forename: Chong-li
authors.initials: CL
authors.lastname: Dedg
authors.forename: Jian-ting
authors.initials: JT
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000077214:Becaplermin; D005260:Female; D006801:Humans; D006984:Hypertrophy / Q000378:metabolism; D055959:Intervertebral Disc Degeneration / Q000378:metabolism* / Q000473:pathology; D017843:Ligamentum Flavum / Q000378:metabolism* / Q000473:pathology*; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D020574:Proto-Oncogene Proteins c-sis / Q000378:metabolism*; D013130:Spinal Stenosis / Q000378:metabolism* / Q000473:pathology
chemical_list: D020574:Proto-Oncogene Proteins c-sis; D000077214:Becaplermin