竹节参总皂苷对妊娠期高血压胎盘滋养细胞氧化应激损伤与过度自噬的影响

目的探讨竹节参总皂苷对妊娠期高血压疾病胎盘滋养细胞氧化应激反应与自噬的影响及作用机制。方法采用100μmol/L亚硝基左旋精氨酸甲酯(N-nitro-L-arginine methylester,L-NAME)处理人胎盘滋养细胞株HTR-8/SV-neo 48 h,并给予竹节参总皂苷(20、40、80μg/mL)干预24 h,采用CCK-8法检测各组细胞活力;采用流式细胞仪检测各组细胞凋亡情况;采用试剂盒检测各组细胞上清液中丙二醛(malondialdehyde,MDA)、超氧化物歧化酶(superoxide dismutase,SOD)和谷胱甘肽(glutataione,GSH)水平;采用qRT-PCR和Western blotting法检测各组细胞脂肪酸结合蛋白4(fatty acid binding protein4,FABP4)m RNA和蛋白表达情况;采用Westernblotting法检测各组细胞微管相关蛋白1轻链3-Ⅱ(microtubule associated protein 1 light chain 3 Ⅱ,LC3-Ⅱ)、LC3-Ⅰ、p62和自噬效应蛋白(Beclin-1)表达情况;采用免疫荧光法检测各组细胞LC3表达情况。结果与模型组比较,竹节参总皂苷组细胞活力显著升高(P0.05),细胞凋亡率显著降低(P0.01);上清液中SOD和GSH水平显著升高(P0.01),MDA水平显著降低(P0.01);FABP4 m RNA和蛋白表达水平显著降低(P0.05);LC3-Ⅱ和Beclin-1蛋白表达水平显著降低(P0.05),p62蛋白表达水平显著升高(P0.05);LC3荧光染色强度降低。结论竹节参总皂苷能够改善妊娠期高血压疾病胎盘滋养细胞中的氧化应激反应,并抑制过度自噬,其机制可能与调控FABP4表达有关。     

Dendritic polyglycerol nanoparticles show charge dependent bio-distribution in early human placental explants and reduce hCG secretion

A thorough understanding of nanoparticle bio-distribution at the feto-maternal interface will be a prerequisite for their diagnostic or therapeutic application in women of childbearing age and for teratologic risk assessment. Therefore, the tissue interaction of biocompatible dendritic polyglycerol nanoparticles (dPG-NPs) with first- trimester human placental explants were analyzed and compared to less sophisticated trophoblast-cell based models. First-trimester human placental explants, BeWo cells and primary trophoblast cells from human term placenta were exposed to fluorescence labeled, ～5?nm dPG-NPs, with differently charged surfaces, at concentrations of 1 µM and 10?nM, for 6 and 24?h. Accumulation of dPGs was visualized by fluorescence microscopy. To assess the impact of dPG-NP on trophoblast integrity and endocrine function, LDH, and hCG releases were measured. A dose- and charge-dependent accumulation of dPG-NPs was observed at the early placental barrier and in cell lines, with positive dPG-NP-surface causing deposits even in the mesenchymal core of the placental villi. No signs of plasma membrane damage could be detected. After 24?h we observed a significant reduction of hCG secretion in placental explants, without significant changes in trophoblast apoptosis, at low concentrations of charged dPG-NPs. In conclusion, dPG-NP’s surface charge substantially influences their bio-distribution at the feto-maternal interface, with positive charge facilitating trans-trophoblast passage, and in contrast to more artificial models, the first-trimester placental explant culture model reveals potentially hazardous influences of charged dPG-NPs on early placental physiology.     

Glyburide treatment in gestational diabetes is associated with increased placental glucose transporter 1 expression and higher birth weight

Use of glyburide in gestational diabetes (GDM) has raised concerns about fetal and neonatal side effects, including increased birth weight. Placental nutrient transport is a key determinant of fetal growth, however the effect of glyburide on placental nutrient transporters is largely unknown. We hypothesized that glyburide treatment in GDM pregnancies is associated with increased expression of nutrient transporters in the syncytiotrophoblast plasma membranes.We collected placentas from GDM pregnancies who delivered at term and were treated with either diet modification (n = 15) or glyburide (n = 8). Syncytiotrophoblast microvillous (MVM) and basal (BM) plasma membranes were isolated and expression of glucose (glucose transporter 1; GLUT1), amino acid (sodium-coupled neutral amino acid transporter 2; SNAT2 and L-type amino acid transporter 1; LAT1) and fatty acid (fatty acid translocase; FAT/CD36, fatty acid transporter 2 and 4; FATP2, FATP4) transporters was determined by Western blot. Additionally, we determined GLUT1 expression by confocal microscopy in cultured primary human trophoblasts (PHT) after exposure to glyburide.Birth weight was higher in the glyburide-treated group as compared to diet-treated GDM women (3764 ± 126 g vs. 3386 ± 75 g; p < 0.05). GLUT1 expression was increased in both MVM (+50%; p < 0.01) and BM (+75%; p < 0.01). In contrast, MVM FAT/CD36 (−65%; p = 0.01) and FATP2 (−65%; p = 0.02) protein expression was reduced in mothers treated with glyburide. Glyburide increased membrane expression of GLUT1 in a dose-dependent manner in cultured PHT.This data is the first to show that glyburide increases GLUT1 expression in syncytiotrophoblast MVM and BM in GDM pregnancies, and may promote transplacental glucose delivery contributing to fetal overgrowth.     

人胎盘滋养层细胞体外感染HCMV后的生物学特性变化

目的探讨人胎盘滋养层细胞（以下简称滋养细胞）感染人巨细胞病毒（HCMV）后生物学特性改变及意义。方法采用复合酶消化法及Pereoll密度梯度离心法分离纯化、培养人滋养细胞;采用HCMV AD169病毒感染滋养细胞,检测不同时间点病毒复制情况和细胞凋亡率。结果HCMV感染滋养细胞后快速复制,24—72h复制速度减慢;感染HCMV的滋养细胞凋亡率（34．68％±3．14％）明显高于未感染HCMV者（15．32％±2．34％）,P〈0．05.结论HCMV感染滋养细胞具有早期快速复制的特点,可导致滋养层细胞在感染早期加速凋亡。     

miR-34a靶向MMP2对TNF-α诱导人绒毛膜滋养层细胞 HTR-8/SVneo迁移及侵袭的影响

目的 探讨微小RNA（miR）-34a靶向基质金属蛋白酶（MMP）2对肿瘤坏死因子（TNF）-α诱导人绒毛膜滋 养层细胞 HTR-8/SVneo 迁移和侵袭的影响。方法 体外培养人绒毛膜滋养层细胞 HTR-8/SVneo,利用 0.5 μg/L TNF-α刺激细胞;将细胞分为对照组、TNF-α诱导组、NC组、miR-34a mimics组、iNC组、miR-34a inhibitor组;实时荧 光定量PCR（qPCR）检测各组细胞中miR-34a、MMP2 mRNA的表达;CCK-8法、Transwell法和划痕实验分别检测各组 细胞增殖、侵袭和迁移情况;蛋白免疫印迹法检测MMP2蛋白的表达;双荧光素酶报告实验证明miR-34a和MMP2的 靶向关系。结果 与对照组比较,TNF-α 诱导组细胞 miR-34a 表达水平、细胞增殖抑制率显著升高（P＜0.05）, MMP2 mRNA和蛋白表达水平、细胞侵袭数目、细胞迁移率显著降低（P＜0.05）;与TNF-α诱导组和NC组比较,miR- 34a mimics组细胞miR-34a表达水平、细胞增殖抑制率显著升高（P＜0.05）,MMP2 mRNA和蛋白表达水平、细胞侵袭 数目、细胞迁移率显著降低（P＜0.05）;与TNF-α诱导组和iNC组比较,miR-34a inhibitor组细胞miR-34a表达水平、 细胞增殖抑制率显著降低（P＜0.05）,MMP2 mRNA和蛋白表达水平、细胞侵袭数目、细胞迁移率显著升高（P＜0.05）; miR-34a与MMP2具有靶向关系。结论 miR-34a可能通过负调控MMP2的表达抑制TNF-α诱导的人绒毛膜滋养 层细胞HTR-8/SVneo迁移和侵袭。     

Expression and characterization of vitamin C transporter in the human trophoblast cell line HTR-8/SVneo: effect of steroids, flavonoids and NSAIDs

Vitamin C plays an important role in embryogenesis and fetal growth as well as in the progression of pregnancy and delivery. Therefore, it is important to understand the mechanism that mediates its transport to the fetus as well as the possible influences by endogenous and exogenous substances on its placental uptake. The aim of this study was to investigate placental sodium-dependent vitamin C transporters (SVCT) 1 and 2. By means of RT-PCR, we found that SVCT2, but not SVCT1, mRNA is expressed in human trophoblast cell line HTR-8/SVneo. Our method was able to confirm SVCT2 mRNA expression in human first-trimester chorionic villi but not in term placental tissue. Cell line kinetic studies of [(14)C] ascorbic acid (AA) uptake indicated a one-site model and a saturable process. Fetal bovine serum (FBS) and epidermal growth factor (EGF) do not influence the transport properties, although they significantly increase the expression of SVCT2. Steroid hormones (17beta-estradiol, progesterone and cortisol), flavonoids (genistein and quercetin) and non-steroidal anti-inflammatory drugs (NSAIDs) (indomethacin and diclofenac) inhibit [(14)C]AA uptake in a dose-dependent and non-competitive manner. On the contrary, the process is not influenced by aspirin. Our study suggests the use of HTR-8/SVneo cells as a suitable model for trophoblast vitamin C transport investigation.     

Immunolocalization of glucose transporter 1 and 3 in the placenta: application to cytodiagnosis of Papanicolaou smear

A positive immunostaining for glucose transporter 1 (GLUT1) was exclusively localized in microvilli on the free surface of syncytiotrophoblasts in the placenta. An enhanced immunoreaction for glucose transporter 3 (GLUT3) was elicited in the cell membrane of intermediate trophoblasts and cytotrophoblasts. Neither GLUT1 nor GLUT3 was positive in decidual cells and epithelial components from cervical dysplasia and carcinoma in situ. Cervicovaginal smears from six pregnant women containing atypical cells of unknown origin were subjected to immunocytochemical testing with antibodies against GLUT1 and GLUT3. Atypical cells in smears from two pregnant women were found to be positive for GLUT3 while no specific immunoreaction for GLUT1 was elicited, indicating their origin from either intermediate trophoblasts or cytotrophoblasts. Through the use of antibodies against vimentin and cytokeratin 17, GLUT3-negative atypical cells were further sorted into decidual cells and epithelial components from cervical dysplasia, respectively.     

Letter From the Editor

ABSTRACT: The NK-susceptibility of trophoblast cells to allogeneic and autologous intraplacental natural killer (NK), antibody-dependent (K), and mitogen-induced cell-mediated cytotoxicity was studied, using untreated and neuraminidase-treated trophoblast cells from normal, full-term deliveries. The work was preceded by systematic studies of placental cell separation and labelling techniques, and the effects of these techniques on the NK target, K562. The results indicated that maternal NK cells are present among intraplacental lymphocytes, but that their activity is lower than that of peripheral blood lymphocytes and they are not stimulated by interferon to the same extent as peripheral blood lymphocytes (PBL). Trophoblast cells were rarely susceptible to allogeneic NK cells, with low cytotoxicity at high effector-target cell ratios in only two of five experiments. Interferon (IF)-boosted NK cells mediated some cytolysis of trophoblasts in three of four experiments, but high effector/target cell ratios were also required for the effect to be observed. The trophoblast cells could be lysed, however, by K cells and lectin-induced cytotoxicity. Removal of surface sialic acid by neuraminidase treatment of the trophoblast cells had little effect on the susceptibility of these cells to unstimulated NK cells (one of four experiments), but resulted in susceptibility to IF-boosted NK cells in four of four experiments. Normal trophoblast cells did not compete in IF-NK(K562) assays and neuraminidase-treated cells competed weakly in only one of three such experiments, indicating that the NK “target structure” is only weakly expressed on human trophoblast cells. Intraplacental lymphocytes lysed autologous trophoblast cells to a lower extent than allogeneic PBL. This lysis was markedly increased if antibody against the target cells was present in the assay. These data indicate that a) the trophoblast cell is susceptible to maternal cell-mediated lysis by several mechanisms that could potentially be activated in vivo, b) NK cells are present in the intraplacental lymphocyte pool, and c) the access of NK cells and interferon activated NK cells to the NK cell target structure is blocked by cell surface sialic acid residues. This target structure may be similar to that found on other susceptible cells, and in similarity to the tumor—NK interaction, the cell surface sialic acid is ineffective in blocking cytotoxicity if the appropriate antibody is present. Assuming NK cells mediate ADCC, this indicates that sialic acid does not mask the target site of the lytic molecule. These data are relevant to the understanding of the NK– target interaction in a situation where it is known that the target is nonself.     

Involvement of peroxynitrite in LPS-induced apoptosis of trophoblasts

OBJECTIVE: To examine whether or not peroxynitrite was involved in trophoblastic apoptosis induced by a bacterial endotoxin, lipopolysaccharide (LPS). METHODS: Levels of nitrite/nitrate, stable metabolites of nitric oxide (NO), in culture medium of trophoblasts, were determined using Griess reagents. Trophoblastic apoptosis was identified morphologically and confirmed using in situ nick end labeling technique. The amount of nitrotyrosine, a footprint of peroxynitrite, was quantified by dot blotting. Statistical significance was determined by ANOVA. RESULTS: Treatment of trophoblasts with LPS leads to apoptosis accompanied by formation of NO and nitrotyrosine. Aminoguanidine, an inhibitor of NO synthase (NOS), reduced peroxynitrite formation and prevented apoptosis. Scavengers of peroxynitrite also prevented apoptosis in this culture model. CONCLUSION: Peroxynitrite was involved in trophoblastic apoptosis induced by LPS. Peroxynitrite scavengers or inhibitors of NOS may thus be candidate therapeutic agents for infectious diseases, which is associated with overproduction of NO and peroxynitrite.