Increased apoptosis in the syncytiotrophoblast in human term placentas complicated by either preeclampsia or intrauterine growth retardation.
OBJECTIVE
This study was undertaken to determine whether preeclampsia and intrauterine growth retardation are associated with an increase in placental apoptosis.


METHODS
Tissue specimens from 7 normal term placentas and each of 7 term placentas complicated by severe preeclampsia or intrauterine growth retardation were analyzed. Fas antigen and Bcl-2 protein expression were examined by the avidin/biotin immunoperoxidase method, whereas apoptosis was assessed by the terminal deoxynucleotidyl transferase deoxy-UTP-nick end labeling (TUNEL) method and transmission electron microscopy.


RESULTS
Fas antigen was immunolocalized in syncytiotrophoblasts in all placentas examined. No changes in the intensity of Fas antigen immunostaining in syncytiotrophoblasts were apparent among those placentas. Bcl-2 protein was abundantly immunolocalized in syncytiotrophoblasts in normal term placentas, but least abundant in term placentas complicated by severe preeclampsia or intrauterine growth retardation. Apoptosis was apparent in the nuclei of both cytotrophoblasts and syncytiotrophoblasts. The apoptosis positive rate of syncytiotrophoblast nuclei in severe preeclamptic and intrauterine growth retardation term placentas was significantly higher than that in normal term placentas (severe preeclampsia, P <.001; intrauterine growth retardation, P <.01). Transmission electron microscopy revealed the appearance of apoptotic nuclei in trophoblasts in severe preeclamptic term placenta.


CONCLUSIONS
Decreased expression of Bcl-2 protein in syncytiotrophoblasts in severe preeclamptic and intrauterine growth retardation placentas may result in the increase in apoptosis in syncytiotrophoblasts in those placentas.
Ishihara
Naonori
N
Department of Obstetrics and Gynecology, Kobe University School of Medicine, Japan.
Matsuo
Hiroya
H
Murakoshi
Homare
H
Laoag-Fernandez
Jovelle B
JB
Samoto
Takashi
T
Maruo
Takeshi
T
D017209:Apoptosis; D005260:Female; D005317:Fetal Growth Retardation / Q000503:physiopathology*; D015726:Giant Cells / Q000502:physiology*; D006801:Humans; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D010920:Placenta / Q000503:physiopathology* / Q000648:ultrastructure; D011225:Pre-Eclampsia / Q000503:physiopathology*; D011247:Pregnancy; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D012016:Reference Values; D014327:Trophoblasts / Q000502:physiology*; D019014:fas Receptor / Q000378:metabolism
D019253:Proto-Oncogene Proteins c-bcl-2; D019014:fas Receptor