细胞凋亡、Smad4及S100B蛋白在孕期铅暴露大鼠胎盘中的表达及意义

发布时间：2018-03-05 10:55

本文选题：铅　切入点：胎盘　出处：《青岛大学》2012年硕士论文　论文类型：学位论文

【摘要】：目的观察胎盘细胞凋亡、Smad4及S100B蛋白在孕期不同阶段铅暴露下大鼠胎盘中的表达特征及其意义。方法108只大鼠随机分为4组,于孕期不同阶段饮服0.025%醋酸铅溶液。原子吸收光谱法测定孕末期血铅水平。Hoechst细胞核染色以及脱氧核糖核苷酸末端转移酶介导的缺口末端标记(TUNEL)技术细胞凋亡检测法测定各组不同孕期铅暴露大鼠胎盘细胞凋亡指数。免疫组化法测定大鼠各组胎盘中Smad4以及S100B蛋白的表达。计量资料组间比较采用单因素方差分析,计数资料组间比较采用卡方检验。结果①实验组血铅水平均高于0.483μmol/L,不同孕期铅暴露大鼠实验组血铅水平与对照组比较差异有统计学意义(F=12.10,P0.01)。②Hoechst染色显示,铅暴露组胎盘滋养层凋亡细胞核浓染,部分核内可见致密块状荧光颗粒,对照组凋亡细胞呈散在分布。TUNEL技术检测显示,铅暴露组大鼠胎盘滋养层凋亡细胞核呈棕黄色,部分核中有棕黄色颗粒。凋亡细胞核较正常增大,呈椭圆形或不规则形,核内染色质聚集于边缘处。两种凋亡检测方法均显示,铅暴露组胎盘细胞凋亡指数高于对照组,且孕期全程铅暴露组高于孕早期和孕晚期铅暴露组(P0.01)。③Smad4主要表达于大鼠胎盘绒毛滋养细胞、毛细血管及间质细胞,在实验组中的表达较对照组增高,差异有统计学意义(F=10.08,P0.01)。与孕早期铅暴露组比较,孕晚期、孕期全程铅暴露组大鼠胎盘的Smad4表达下降,差异有统计学意义(P0.05)。④S100B蛋白主要表达于大鼠胎盘细胞滋养层细胞、蜕膜细胞及血管壁细胞胞质中,实验组阳性表达率高于对照组(52.94%),且孕期全程铅暴露组(93.33%)高于孕早期(87.50%)和孕晚期铅暴露组(80.00%),差异有统计学意义(x2=18.62,P0.05)。结论胎盘细胞凋亡、Smad4及S100B蛋白在孕期不同阶段铅暴露下大鼠胎盘中的表达与孕末期血铅水平密切相关。细胞凋亡是铅致胎盘损伤的重要机制之一。Smad4及S100B蛋白在铅致胎盘细胞凋亡的发生发展中具有重要作用。
[Abstract]:Objective to investigate the expression of Smad4 and S100B proteins in placenta of rats exposed to lead during pregnancy. Methods 108 rats were randomly divided into 4 groups. 0.025% lead acetate solution was taken at different stages of pregnancy. Determination of blood lead level. Hoechst nuclear staining by atomic absorption spectrometry and detection of apoptosis by deoxyribonucleotide terminal transferase-mediated Nick end labeling (Tunel) technique. The expression of Smad4 and S100B protein in placenta of rats exposed to lead in each group was determined by immunohistochemical method. The results were analyzed by single factor analysis of variance (ANOVA). The counting data were compared by chi-square test. Results (1) the blood lead levels in the experimental group were higher than 0.483 渭 mol / L, and there was a significant difference between the experimental group and the control group in the blood lead levels during different pregnancy periods. The results of Hoechst staining showed that the apoptotic nuclei of placental trophoblastic layer in the lead exposure group were strongly stained. Dense massive fluorescent granules could be seen in some nuclei. The apoptotic cells in the control group were scattered in distribution. Tunel technique showed that the apoptotic nuclei of placental trophoblastic layer of rats exposed to lead were brownish yellow. There were brown granules in some nuclei. The apoptotic nuclei were oval or irregular in shape. The chromatin in the nuclei gathered at the edge. The apoptotic index of placenta cells in lead exposure group was higher than that in control group, both methods showed that the apoptosis index of placental cells in lead exposure group was higher than that in control group. The results showed that the expression of P0.01C. 3Smad4 in placental villus trophoblast, capillary and interstitial cells was higher in the experimental group than in the control group, and it was higher in the lead exposure group during pregnancy than that in the early and late pregnancy groups, and the expression of Smad4 was higher in the experimental group than in the control group. Compared with the lead exposure group in early pregnancy, the expression of Smad4 in placenta of rats exposed to lead during pregnancy was decreased, and the protein of P0.05, 4S100B was mainly expressed in trophoblast cells of rat placenta. The positive expression rate of decidual cells and vascular wall cells in the experimental group was higher than that in the control group (52.94) and the lead exposure group during pregnancy (93.33) was higher than that in the first trimester of pregnancy (87.50%) and in the late stage of pregnancy (80.005%). The difference was statistically significant. Conclusion the expression of Smad4 and S100B proteins in placenta of rats exposed to lead in different stages of pregnancy is closely related to the level of blood lead in late pregnancy. Apoptosis is one of the important mechanisms of placental injury induced by lead, Smad4 and S100B proteins. Lead-induced placental apoptosis plays an important role in the development of placental cell apoptosis.
【学位授予单位】：青岛大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R179

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