基质金属蛋白酶与子痫前期发病关系的研究

目的 探讨基质金属蛋白酶(MMP)2、9在子痫前期患者胎盘绒毛中的表达及其与子痫前期发病的关系.方法 采用免疫组化链霉亲和素-生物素-过氧化物酶复合物(SABC)法检测20例子痫前期患者(病例组)和20例正常孕妇(对照组)胎盘绒毛MMP-2、9的表达,实时荧光定量RT-PCR检测两组孕妇胎盘绒毛MMP-2、9 mRNA的表达水平.因提取后的mRNA部分降解,用于RT-PCR检测的胎盘绒毛病例组13份,对照组10份.采用2-△△Ct相对定量表示PCR结果.结果 对照组孕妇胎盘绒毛MMP-2、9的染色强度均高于病例组,两组比较,差异有统计学意义(P＜0.05);对照组胎盘绒毛MMP-2 mRNA的平均表达水平为7.6±2.8,病例组胎盘绒毛MMP-2 mRNA的平均表达水平为5.6±1.5,两组比较,差异有统计学意义(P＜0.05).对照组胎盘绒毛MMP-9 mRNA的平均表达水平为2.2±2.6,高于病例组的-0.9±2.0,两组比较,差异也有统计学意义(P＜0.05).对照组胎盘绒毛MMP-2的平均表达水平高于MMP-9,两者比较,差异有统计学意义(P＜0.05).结论 MMP-2、9表达降低导致的滋养细胞侵袭能力的下降,可能与子痫前期的发病相关.     

2-Methoxyoestradiol levels and placental catechol-O-methyltransferase expression in patients with late-onset preeclampsia

Purpose

Deficiencies in placental catechol-O-methyltransferase (COMT) and circulating 2-methoxyoestradiol (2-ME) have been shown to be related to early onset preeclampsia. The aim of this study was to investigate levels of 2-ME in the serum and urine of patients with late-onset preeclampsia and to compare those levels to those of normal pregnant women. In addition, we examined placental COMT expression in both groups.

Methods

Fifteen patients with preeclampsia and 15 normal pregnant women were enrolled. 2-ME levels were evaluated by ELISA and placental COMT expression was examined by Western blot analysis.

Results

2-ME levels in serum [median 181.1 pg/mL, interquartile range (IQR) 119.6–244.3 vs. 61.2 pg/mL, IQR 12.0–133.7, respectively, p = 0.004] and urine (median 143.3 pg/mL, IQR 35.0–328.2 vs. 0.5 pg/mL, IQR 0.4–4.6, respectively, p < 0.001) were significantly increased in patients with late-onset preeclampsia compared to those in normal pregnant women at term. There was no significant difference in placental COMT expression between the two groups.

Conclusion

Increased levels of 2-ME in patients with late-onset preeclampsia might be a product of a compensatory mechanism in patients with late-onset preeclampsia.     

Differential expression of human placental PAPP-A2 over gestation and in preeclampsia

IntroductionPregnancy Associated Plasma Protein A2 (PAPP-A2) is a pregnancy related insulin-like growth factor binding protein-5 (IGFBP-5) protease, known to be elevated in preeclampsia. As the insulin-like growth factors are important in human implantation and placentation, we sought to determine the expression pattern of PAPP-A2 over human gestation in normal and preeclamptic pregnancies to evaluate its role in placental development and the pathogenesis of preeclampsia.MethodsPlacental basal plate and chorionic villi samples, maternal and fetal cord blood sera were obtained from preeclamptic and control pregnancies. Formalin-fixed tissue sections from across gestation were stained for cytokeratin-7, HLA-G, and PAPP-A2. PAPP-A2 immunoblot analysis was also performed on protein lysates and sera.ResultsPAPP-A2 expression is predominately expressed by differentiated trophoblasts and fetal endothelium. Chorionic villi show strong expression in the first trimester, followed by a progressive decrease in the second trimester, which returns in the third trimester. PAPP-A2 expression is not impacted by labor. PAPP-A2 is increased in the basal plate, chorionic villi and maternal sera in preeclampsia compared to controls, but is not detectable in cord blood.DiscussionPAPP-A2 is differentially expressed in different trophoblast populations and shows strong down regulation in the mid second trimester in chorionic villous samples. Both maternal sera and placental tissue from pregnancies complicated by preeclampsia show increased levels of PAPP-A2. PAPP-A2 levels are not altered by labor. Additionally, PAPP-A2 cannot be detected in cord blood demonstrating that the alterations in maternal and placental PAPP-A2 are not recapitulated in the fetal circulation.     

Accelerated expression of Ca antigen by placental villous trophoblast in preeclampsia

The Ca antigen is expressed by a range of normal tissues, as well as by many malignant neoplasms. The former includes placental villous syncytiotrophoblast where it appears first on syncytial sprouts at 20 weeks gestation, and progressively becomes more intensely and widely expressed on the surface of the trophoblast of villi of all sizes. We report here the prematurely intense expression of the antigen in pre-eclampsia (22 cases), by comparison with control sections from uncomplicated pregnancies. The expression of this antigen may have value as a relatively objective marker of accelerated maturation of the placental villous tree. It is suggested that the premature expression of Ca antigen in villous trophoblast in pre-eclampsia is due to external modification of a temporally related gene activation.     

Increased placental sFlt-1 but unchanged PlGF expression in late-onset preeclampsia

Objective: To investigate whether differences between late-onset preeclampsia (PE) and intrauterine growth restriction (IUGR) can be explained by differential placental expression patters of sFlt-1, Flt-1, and placental growth factor (PlGF).

Methods: Placental tissues and maternal blood samples from seven patients with PE, five IUGR, and seven age-matched controls were studied for mRNA and protein levels as well as protein localization and expression intensity.

Results: Placental PlGF mRNA and protein expression were not altered by placental dysfunction while placental villous trophoblast expression intensity of PlGF was increased.

Conclusion: High sFlt-1 concentrations may account for diminished maternal serum PlGF levels.     

Inhibin expression in normal and pre-eclamptic placental tissue.

Serum inhibin levels increase during normal pregnancy, but are significantly higher in patients with pre-eclampsia. The aim of this study was to demonstrate possible increased expression of inhibin within the placentas of women with pre-eclampsia compared with non-pre-eclamptic controls. Cellular expression of inhibin alpha and beta A subunits was studied using immunohistochemistry on formalin-fixed, paraffin-embedded placental sections from cases of pre-eclampsia (n = 23) and gestational age-matched non-pre-eclamptic controls (n = 16). Immunohistochemistry was performed using monoclonal antibodies against inhibin alpha and beta A subunits by the indirect immunoperoxidase technique. Intensity of staining was graded by a semiquantitative scoring method. Differences in distribution and intensity of staining between control and pre-eclamptic placentas were analyzed using a nonparametric Mann-Whitney U test. Staining for both inhibin alpha and beta A was predominantly confined to the cytoplasm of syncytiotrophoblast, with weak expression within intermediate trophoblast. The intensity of staining for inhibin alpha was significantly greater in the syncytiotrophoblast of pre-eclamptic patients (mean staining intensity controls = 0.97, disease = 1.87; p < 0.001). Inhibin beta A staining was generally stronger than for the alpha subunit, and was also significantly increased in pre-eclamptic patients compared with controls (mean controls = 1.72, disease 2.19; p < 0.05). This is the first evidence for increased placental inhibin presence in pre-eclampsia, suggesting increased inhibin production within the placenta, a finding that could account for increased serum inhibin levels in pre-eclampsia.     

脂代谢相关基因ADRP和LPL在子痫前期胎盘组织表达的改变

目的:研究子痫前期患者胎盘组织中脂代谢相关基因的表达,探讨子痫前期脂肪代谢紊乱的可能原因。方法:利用基因芯片检查4例子痫前期胎盘与4例正常胎盘之间的差异表达基因;采用半定量RT-PCR方法验证子痫前期胎盘组织(研究组)和正常孕妇胎盘组织(对照组)脂代谢相关基因脂肪分化相关蛋白(ADRP)基因和脂蛋白脂酶(LPL)基因mRNA的表达改变。结果:在4轮杂交过程中,共筛选出22条有差异表达的基因,其中表达增高的基因有脂肪分化相关蛋白基因(NM-001122)等13条;表达降低的基因有脂蛋白脂酶基因(NMM-000237)等9条。研究组ADRPmRNA相对表达水平为1·98±0·50,显著高于对照组的1·09±0·20(P<0·01);研究组LPLmRNA相对表达水平为0208±0·067,显著低于对照组的0·524±0·139(P<0·05)。结论:脂代谢相关基因ADRP和LPL在子痫前期胎盘组织的异常表达可能是导致子痫前期发病的原因之一。     

Altered placental syncytin and its receptor ASCT2 expression in placental development and pre-eclampsia

OBJECTIVE: To investigate the alterations of syncytin, a fusogenic membrane protein involved in syncytiotrophoblastic layer formation, and its receptor ASCT2 expression in placental development and pre-eclampsia. DESIGN: Analyses of syncytin and ASCT2 expression in placentas from different stages of pregnancy and women with pre-eclampsia and in cytotrophoblasts cultured in normoxic and hypoxic conditions. SETTING: Placental samples were collected from a tertiary medical centre. POPULATION: Sixteen women with pre-eclampsia and 58 pregnant women presented as pregnancy (5-19 weeks of gestation) for elective termination, preterm birth, or normal term delivery. METHODS: The quantitative real-time polymerase chain reaction was used to study the syncytin and ASCT2 expression during placental development in 35 placentas from women without pre-eclampsia (ranged from 5 to 40 weeks of gestation) and the alterations of pre-eclamptic placentas (n=16) compared with gestational-age-matched controls (n=16). Western blot analysis was performed to study the protein level of syncytin in pre-eclamptic placentas and gestational-age-matched controls. The hypoxic effect on trophoblastic syncytin and ASCT2 expression was further studied in cytotrophoblasts cultured in 2% oxygen (n= 7). MAIN OUTCOME MEASURES: Syncytin and ASCT2 messenger RNA (mRNA) in placental tissue and cytotrophoblasts. RESULTS: The level of syncytin mRNA expression increased significantly since the first trimester of pregnancy until 37 weeks of gestation, when the level of syncytin expression was reduced. The ASCT2 mRNA expression was decreased significantly since the second trimester and was relatively stable since then to 40 weeks of gestation. Furthermore, a significant reduction in syncytin mRNA expression was observed in pre-eclamptic placentas and cytotrophoblasts cultured in hypoxia, but not a reduction in ASCT2 mRNA expression. Correlatively, the protein level of syncytin was decreased in pre-eclamptic placentas. CONCLUSIONS: A reduced placental expression of syncytin but not ASCT2 may contribute to altered cytotrophoblastic cell fusion processes and disturbed placental function in pre-eclampsia. Correspondingly, hypoxia decreases syncytin but not ASCT2 gene expression in cultured cytotrophoblasts.     

胎盘微环境改变与子痫前期

胎盘对于胎儿发育至关重要,胎儿血与母体血在胎盘单位内进行养分交换。子痫前期发病的关键环节即为滋养细胞浸润不足引起的对子宫螺旋动脉重塑障碍。可溶性血管内皮生长因子受体-1与胎盘生长因子的比值在子痫前期的发病、诊断及不良妊娠结局的发生率中可能有重要预测价值。     

Serum and placental interleukin-18 are elevated in preeclampsia

OBJECTIVES: Interleukin-18 (IL-18) is a proinflammatory cytokine with pleiotrophic qualities and its roles in pregnancy, labor onset and pregnant complications have been proposed. However, the alterations of serum and placental IL-18 have been less investigated. The objective of the current investigation was to detect IL-18 concentrations in serum and placentas from patients with preeclampsia and women with normal pregnancy. METHODS: 27 patients with preeclampsia and 28 women with normal pregnancy were recruited. Blood and placental samples were taken and IL-18 concentrations in serum and placental homogenate were analyzed by enzyme-linked immunosorbent assay (ELISA). The levels of IL-18 in serum and placenta were compared between preeclampsia and control. RESULTS: Both serum and placental levels of IL-18 were significantly increased in preeclampsia as compared with control (P=0.014 and 0.003, respectively). Serum and placental levels of IL-18 were not significantly different in preeclamptic women who received dexomethasone and those who did not (P=0.223 and 0.330, respectively). Serum and placental IL-18 levels were not significantly different between preeclamptic women who delivered before 36 complete gestational weeks and those who delivered after 36 complete weeks (P=0.616 and 0.869, respectively). There were no significant differences in serum and placental IL-18 between women with mild preeclampsia and those with severe preeclampsia (P=0.056 and 0.357, respectively). CONCLUSIONS: Increased serum and placental levels of IL-18 were observed in preeclampsia. Those associations may offer insight into the pathogenesis of the disease.     

Metabolism of vitamin D3 in the placental tissue of normal and preeclampsia complicated pregnancies and premature births

The aim of this study was to analyze the hormonal basis for low 1,25(OH)2D3 circulating levels in patients with preeclampsia and/or preterm deliveries. The activity and expression of the 1 alphaOHase, 25-OHase, 24-OHase and VDR in the placental tissue of normal pregnancies, preeclampsia-complicated pregnancies and premature births were investigated. The mRNA of the enzymes was detected in the placental tissue from preeclamptic pregnancies and compared to those of normal placental tissue. Real time PCR analysis showed a significant increased 1 alpha-OHase gene expression in preeclamptic patients, and the gene expression of 24-OHase was significantly decreased. With regard to the 25-OHase the median value of the normal placental tissue was significantly higher than in the placental tissue of preeclamptic patients. The real time analysis of all target genes also showed significant differences in normal placental tissue compared to placental tissue from premature births (VDR: p = 0.041; 1 alpha-OHase: p = 0.013; 24-OHase: p = 0.007; 25-OHase p = 0.027). Our observation of reduced VDR expression on mRNA level in placental tissue indicates a possible dependence of the modulation of VDR expression from proliferation and differentiation processes. It can be speculated whether the down-regulation of VDR in the examined placenta cells was the result of an altered production of calcitriol by these cells. We found a significantly higher 1 alpha-OHase-expression in the placental tissue of pregnant women with preeclampsia or preterm birth compared to healthy pregnant women, whereas the expression of 25-OHase was significantly reduced. These results correlate with other studies and support the significance of the placenta regarding metabolism malfunctions as they were observed in the calcium metabolism for preeclampsia. That a placenta with preeclampsia expresses less 1 alpha-OHase-mRNA and shows less 1 alpha-OHase-activity than in placental samples of inconspicuous placentae, can be granted as a specific alteration in the placental ability to synthesize adequate amounts of 1,25(OH)2D3.     

妊娠期及妊高征滋养细胞E-钙粘附素的表达

目的 :研究妊娠各期胎盘床绒毛外细胞滋养细胞 (EVT)E 钙粘附素 (E cad herin)表达的变化 ,并与妊高征胎盘床中的表达进行比较。方法 :用免疫组化法 ,对 4 0例标本进行染色 (孕早期 9份 ,孕中期 4份 ,孕晚期 2 7份 ,其中妊高征组 8份 ,非妊高征组 19份 )。结果 :孕 10周前绒毛的细胞滋养细胞仅小部分E cadherin染色呈弱阳性。孕 10周后 ,绒毛的细胞滋养细胞染色均为强阳性 ,细胞柱区域从近端到远端染色逐渐减弱。孕中期EVT染色几乎为阴性 ,孕晚期又稍有增强。妊高征时EVT染色减弱不明显。妊高征组和非妊高征组染色阳性的细胞分别为 2 7.4 5 %和 12 .74 % (P <0 .0 1)。结论 :E cadherin表达减弱或消失有利于细胞滋养细胞的浸润。妊高征时 ,E cadherin表达减弱不明显 ,细胞滋养细胞浸润能力减弱 ,以至螺旋动脉缺乏妊娠期生理性变化 ,导致发生妊高征。     

Altered perlecan expression in placental development and gestational diabetes mellitus

The proteoglycan perlecan is involved in cell signaling, regulation of growth factor activity, and maintenance of basement membranes. This study aims to investigate the expression of perlecan during placental development and whether hyperglycemia of gestational diabetes mellitus induces the alteration of perlecan expression in placenta. Immunohistochemistry, immunoprecipitation/sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and quantitative real-time PCR were carried out to study the placental perlecan expression at different trimesters of pregnancies and in gestational diabetes mellitus. The perlecan protein was mainly immunolocalized in the trophoblast and vessel basement membranes with some staining in the villous stroma of placental villus. Perlecan was also found to co-localize with laminin and collagen IV in the basement membranes of placenta. The protein and mRNA levels of placental perlecan were significantly decreased as the gestational age increased. However, a significant increase in perlecan expression was observed in the third trimester placentas with gestational diabetes mellitus compared to the gestational age-matched controls. Furthermore, trophoblast cells cultured in a high glucose (30 mM) medium and a high osmotic pressure medium (5.6 mM glucose and 24.4 mM mannitol) showed increased perlecan expression compared to cells cultured in the low glucose (5.6 mM) regular medium. These alterations of perlecan expression may be associated with the structural changes of placenta during maturation. The metabolic effect of high glucose and high osmotic pressure of gestational diabetes mellitus may contribute to the increased perlecan expression of diabetic placentas.     

Increased placental apoptosis in pregnancies complicated by preeclampsia

Placentas were obtained at delivery from 34 pregnancies complicated by preeclampsia and from 34 uncomplicated pregnancies. The incidence of apoptotic nuclei was significantly greater (P <.01) in the placentas from the pregnancies complicated by preeclampsia.