title: [Expression of matrix metalloproteinase-9 and tumor necrosis factor-alpha in the placenta of patients with pregnancy-induced hypertension].
abstract: OBJECTIVE
  To investigate the role of matrix metalloproteinase-9 (MMP-9) and tumor necrosis factor-alpha (TNF-alpha) in the pathogenesis of pregnancy-induced hypertension (PIH).
  
  
  METHODS
  The placenta samples were collected from 57 patients with PIH and 24 normal pregnant women. Immunohistochemical staining was used to examine positive expression of MMP-9 and TNF-alpha in these samples.
  
  
  RESULTS
  The positive expression of MMP-9 in the normal group was significantly higher than that in patients with moderate or severe PIH (P<0.01), while no significant difference was found between normal pregnant women and patients with mild PIH (P>0.05), and expression decreased drastically with the progression of PIH (P<0.05). The expression of TNF-alpha in the patients with mild, moderate and severe PIH groups were significantly higher than that in the normal group (P<0.05, P<0.01 and P<0.01, respectively), and the differences were also significant between the PIH groups of different severities (P<0.01). No correlation was found between MMP-9 and TNF-alpha expressions in the normal and mild PIH groups (r=0.287, P>0.05; r=0.382, P>0.05), in the patients with moderate and severe PIH, MMP-9 expression showed inverse correlation with TNF-alpha expression (r=-0.563, P<0.05; r=-0.681, P<0.01).
  
  
  CONCLUSIONS
  Lowerd MMP-9 expression in syncytiotrophoblast might result in defective nidation in the placenta where local ischemia and hypoxia cause abnormal TNF-alpha elevation, which might be one of the important factors inducing PIH.
authors.affiliation: Department of Obstetrics, Affiliated Hospital of Medical College of Qingdao University, Qingdao 266003, China. nnns6@yahoo.com.cn
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhan
authors.forename: Wei-ping
authors.initials: WP
authors.lastname: Chen
authors.forename: Yuan-hua
authors.initials: YH
authors.lastname: Ye
authors.forename: Yan-hui
authors.initials: YH
authors.lastname: Lou
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis*; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
chemical_list: D014409:Tumor Necrosis Factor-alpha; D020780:Matrix Metalloproteinase 9