Fetus-Placenta-Newborn
Increased apoptosis in the syncytiotrophoblast in human term placentas complicated by either preeclampsia or intrauterine growth retardation,☆☆

https://doi.org/10.1067/mob.2002.119176Get rights and content

Abstract

Objective: This study was undertaken to determine whether preeclampsia and intrauterine growth retardation are associated with an increase in placental apoptosis. Study Design: 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. Conclusion: 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.(Am J Obstet Gynecol 2002;186:158-66.)

Section snippets

Placental materials

Normal term placentas between 37 and 38 weeks of singleton pregnancy were obtained from 7 patients who had cesarean deliveries for various indications such as previous cesarean delivery and breech presentation. All normal term infants had birth weights ≥10th percentile of the individualized birth weight ratio. Term placentas complicated by either severe preeclampsia or IUGR from a singleton pregnancy between 36 and 37 weeks of gestation were obtained from each of 7 patients who had cesarean

Results

Immunohistochemical analysis of Fas antigen expression in the human placenta demonstrated that Fas antigen was immunolocalized in the cytoplasm and cell membranes of S-cells of all term placentas examined. There were no apparent differences in the intensity of Fas antigen immunostaining in S-cells among normal term placentas, severe preeclamptic term placentas, and IUGR term placentas (Fig 1, A, B, and C ).

. Immunohistochemical staining of Fas antigen in sections of normal term placenta (A),

Comment

Preeclampsia and IUGR are frequent and unpredictable syndromes, which are dangerous for the fetus. Although these syndromes were most eagerly studied, they are still least understood. Several reports have detailed the morphologic characteristics of placentas complicated by preeclampsia or IUGR. Arkwright et al6 reported that villous trophoblasts in preeclamptic placentas were phenotypically immature on the basis of both ultrastructural and biochemical criteria when compared with villous

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    Supported in part by the Grants in Aid for Scientific Research (10470346); from the Japanese Ministry of Education, Scientific and Culture: and by the Ogya donation.

    ☆☆

    Reprint requests: Takeshi Maruo, MD, Department of Obstetrics and Gynecology, Kobe University School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan. e-mail: [email protected].

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