The Expression of Apoptosis and Proliferation in the Placental Trophoblast Between Normal and Preeclampsia Women
| Autor: | Tien-Yung Wei, 魏添勇 |
|---|---|
| Rok vydání: | 2008 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 96 Background Preeclampsia is characterized by hypertension, edema, and proteinuria and affects 7-10% of all pregnancies. It is a major cause of maternal and fetal morbidity and mortality, but its etiology remains unknown. The human placenta is a tumorlike organ in which proliferation, migration, and invasion of extravillous trophoblastic cells take place. Trophoblastic cells migrate and invade the uterus and its vasculature to provide a vital link between the mother and the developing fetus. Trophoblastic cell play an important role in maintance of placental function. Little information, however, is available on the roles of apoptosis and proliferation in the trophoblast of placenta in relation to the pathophysiology of preeclampsia. Objectives The aim of the study was to compare the difference between preeclampsia and normal term pregnancy placenta in the expression of some proliferation and apoptotic/anti-apoptotic markers in the human placenta. Materials and Methods Placental samples were obtained form 7 normal uncomplicated term pregnancy and 7 preeclampsia patients. Placenta samples were collected during cesarean section. None of the patients were in labor. After extraction of the newborn, placental insertion was verified and the placenta was rapidly delivered. Placenta villi were corrected in the center part of the placenta avoiding infracted areas. Apoptosis was assessed by the terminal deoxynucleotidyl transferase deoxy-UTP-nick end labeling(TUNEL) method. Expression of Ki-67, Bcl-2, BMP family (bone morphogenetic protein)、CD 34、VEGF( vascular endothelial growth factor) & VEGF receptor-II were assessed using immunohistochemistry. Light microscopy was used to quantify its incidence. The positive index rate (%) was defined as (positive stain cells/ total nuclei) X 100 and expressed as mean ± SD. The Bcl-2 and VEGF expression were assessd by semiquantitative Immunohistochemical Remmele Score(IRS). For each placenta, 5 randomized fields are examined by light microscopy at a magnification of x 200(x 20 objective lens and x 10 eyepiece). Statistical significance was determined by using analysis of variance to compare the rates between normal and preeclampsia placentas. Statistical significance was considered to be present at P < 0.05. ( Mann Whitney U test). Result The TUNEL-positive cells of the placenta were trophoblast with cluster of nuclei and the TUNEL-positive index of these cells was 0.37% ± 0.04% and normal placenta was 0.18% ± 0.05%. The Ki-67-positive index cells was 4.6% ± 0.2% and normal placenta was 3.9% ± 0.3%. The incidence of apoptosis and Ki-67 expression were significantly higher in preeclampsia placentas compared with normal. In contrast the Bcl-2 expression was lower in preeclampsia than normal, although no significant difference. And VEGF protein was higher in preeclampsia than normal, although still no significanct difference. The other expression markers ( ex. CD34, BMP protein family, VEGF receptor) were no statistical significance difference between preeclampsia and normal placentas. Conclusion These results suggest that trophoblast proliferation and apoptosis may paly a role in the pathophysiologic mechanisms of preeclampsia. |
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