title: Reduced amount of cytochrome c oxidase subunit I messenger RNA in placentas from pregnancies complicated by preeclampsia.
abstract: BACKGROUND
  Cytochrome c oxidase is a marker enzyme of the mitochondrial inner membrane. A change in the structure and activity of cytochrome c oxidase may alter the electron transport in the inner membrane, leading to insufficient adenosine triphosphate (ATP) production. ATP is essential for maintaining the function of cells. The aim of this study was to compare the expression of cytochrome c oxidase subunit I mRNA in placentas from normal and preeclamptic pregnancies.
  
  
  METHODS
  By means of in situ hybridization, frozen sections of placentas from 23 women with preeclampsia and 29 women with uneventful pregnancies were examined. Digoxigenin (DIG)-labeled probes were used to detect the expression of cytochrome c oxidase subunit I mRNA in the placentas. The expression density was assessed by using an image disposal and analysis system.
  
  
  RESULTS
  Positive expression of cytochrome c oxidase subunit I mRNA was found in the cytoplasm of villous syncytiotrophoblasts. The mean light density of cytochrome c oxidase subunit I mRNA in placental villi of normal pregnant women was 0.2638, and 0.1763 in women with preeclampsia, a statistically significant difference (P < 0.05). The number density of cytochrome c oxidase subunit I mRNA in placental villi was also significantly reduced in preeclamptic women compared with the control group (P < 0.05).
  
  
  CONCLUSIONS
  Our study demonstrates a reduced amount of cytochrome c oxidase subunit I mRNA in preeclamptic placentas compared to control placentas. We hypothesize that a reduced expression may play a role in the pathophysiology of preeclampsia.
authors.affiliation: Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. qiasanbao@yahoo.com
authors.forename: Liping
authors.initials: L
authors.lastname: He
authors.forename: Zehua
authors.initials: Z
authors.lastname: Wang
authors.forename: Yongyu
authors.initials: Y
authors.lastname: Sun
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003576:Electron Transport Complex IV / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D017403:In Situ Hybridization; D010920:Placenta / Q000201:enzymology*; D011225:Pre-Eclampsia / Q000201:enzymology* / Q000503:physiopathology; D011247:Pregnancy; D012333:RNA, Messenger / Q000235:genetics; D014327:Trophoblasts / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D003576:Electron Transport Complex IV