Glycocalyx Syndecan-1 in Trophoblast Lipid Transport

滋养层脂质运输中的 Glycocalyx Syndecan-1

• 批准号: 9039780
• 负责人: Carl A Hubel
• 金额: $ 9.4万
• 依托单位: MAGEE-WOMEN'S RES INST AND FOUNDATION
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2018-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9039780
• 关键词: Acid Lipase; Apical; Bathing; Binding; Blood; Blood Circulation; Blood capillaries; Cell Line; Cell membrane; Cell surface; Cells; Charge; Cholesterol; Chorionic villi; Chylomicrons; Clinical; Communication; Competitive Binding; Coupled; Data; Development; Endocytosis; Energy-Generating Resources; Enzymes; Epithelial; Familial Hypercholesterolemia; Fetal Development; Fetal Growth; Fetus; Fibroblasts; Functional disorder; Future; Gases; Giant Cells; Glycerol; Glycocalyx; Glycoproteins; Growth; Health; Hep3B; Heparan Sulfate Proteoglycan; Heparin; Heparin Lyase; Heparitin Sulfate; Hepatic; Hepatocyte; Human; Hydrolysis; Infant; Investigation; LDL-Receptor Related Protein 1; Ligand Binding; Ligands; Lipase; Lipids; Lipoprotein Binding; Lipoprotein Receptor; Lipoproteins; Low Density Lipoprotein Receptor; Measures; Mediating; Membrane; Mesenchymal; Molecular Profiling; Mothers; Nonesterified Fatty Acids; Nutrient; Organ; Pathway interactions; Patients; Placenta; Plasma; Play; Pre-Eclampsia; Pregnancy; Primary carcinoma of the liver cells; Proteins; Proteoglycan; Research; Research Project Grants; Risk; Role; SR-B proteins; Series; Side; Signal Transduction; Small for Gestational Age Infant; Source; Surface; Syncytiotrophoblast; System; Testing; Tissues; Triglycerides; VLDL receptor; Very low density lipoprotein; Villous; Villus; Woman; Work; capillary; cellular microvillus; design; fetal; fetal blood; lipid transport; lipoprotein triglyceride; member; normotensive; overexpression; particle; prenatal; public health relevance; receptor; research study; sulfation; syndecan; tool; trophoblast; uptake; very low density lipoprotein triglyceride

 DESCRIPTION (provided by applicant): The syncytiotrophoblast (STB) has critical functions including transport of gases and nutrients to the fetus. Maternal very low-density lipoproteins (VLDL) provide a significant source of free fatty acids (FFA), important for fetal growth and development. VLDL triglycerides are hydrolyzed to FFA by lipases expressed on the STB microvillous membrane (MVM), with FFA transferred to the fetus. Alternatively, however, maternal lipoproteins interact with receptors on the STB MVM, with endocytosis and intracellular hydrolysis. However, relatively little is known about the function of lipoprotein receptors on the trophoblast microvillous membrane, especially with regard to VLDL transport. Disruption of the overall system of placental lipid transfer can have a negative impact on the development of the fetus. The cell surface heparan sulfate proteoglycan (HSPG), syndecan-1 (SDC-1) functions as a receptor for various macromolecular cargo. On microvilli of hepatocytes, SDC-1 mediates cellular internalization of VLDL and remnant lipoproteins. Our preliminary data suggest that trophoblasts likewise bind and internalize VLDL by an HSPG-dependent mechanism, and that trophoblast expression of SDC-1 is significantly reduced in preeclamptic pregnancies. The hypothesis of this R03 proposal is that trophoblasts bind and internalize VLDL by an HSPG-dependent mechanism, and SDC-1 is the primary HSPG effecting this uptake. This will be tested using cells in culture, primarily 1) the human HTR-8/SVneo trophoblast cell line (HTR-8); 2) human Hep3B hepatocarcinoma cells as a positive control for SDC-1 -mediated VLDL uptake; and 3) a line of human fibroblasts (GM00701) that do not express the low-density lipoprotein (LDL) receptor and do not express SDC-1, but express high levels of functional LRP1 (multifunctional member of the LDL receptor superfamily). Aim 1, which builds upon our preliminary data, is to ascertain the role of trophoblast cell surface HSPGs in VLDL binding/uptake. Aim 2 is to determine whether the HSPG-dependent VLDL binding/uptake is primarily accomplished by SDC-1. Aim 3 is to rule out involvement of LRP1 in trophoblast internalization of VLDL. Aim 4 is to measure VLDL binding/uptake by placental villi in explant culture, comparing villi from women with preeclampsia versus uncomplicated pregnancy. The proposed work will further our understanding of lipoprotein handling by STB, and HSPG function in this regard. The research has important clinical implications given the vital importance of placental nutrient transport.

 描述（由适用提供）：合成型植物细胞（STB）具有关键功能，包括将气体和养分运输到胎儿。母体非常低密度的脂蛋白（VLDL）提供了重要的游离脂肪酸（FFA）来源，对胎儿生长和发育很重要。 VLDL甘油三酸酯通过在STB Microville膜（MVM）上表达的脂肪酶水解为FFA，FFA转移到胎儿。然而，然而，母体脂蛋白与STB MVM上的受体相互作用，内吞作用和细胞内水解。然而，关于脂蛋白受体在滋养细胞微叶膜上的功能相对较少，尤其是在VLDL转运方面。斑点脂质转移的整体系统的破坏可能会对胎儿的发展产生负面影响。细胞表面硫酸盐蛋白聚糖（HSPG），Syndecan-1（SDC-1）作为各种大分子货物的接收器。在肝细胞的微绒毛上，SDC-1介导VLDL和残余脂蛋白的细胞内在化。我们的初步数据表明，滋养细胞同样通过HSPG依赖性机制结合并内化VLDL，并且先兆子痫妊娠的滋养细胞表达显着降低了SDC-1的表达。该R03提案的假设是，通过HSPG依赖性机制结合和内化VLDL，而SDC-1是影响这种吸收的主要HSPG。这将在培养物中使用细胞进行测试，主要1）人类HTR-8/Svneo滋养细胞细胞系（HTR-8）； 2）人hep3b肝癌细胞作为SDC -1介导的VLDL摄取的阳性对照； 3）不表达低密度脂蛋白（LDL）受体且未表达SDC-1的人类成纤维细胞（GM00701）系（GM00701），而是表达高水平的功能性LRP1（LDL受体超级家族的多功能成员）。 AIM 1基于我们的初步数据，是确定滋养层细胞表面HSPG在VLDL结合/摄取中的作用。 AIM 2是确定HSPG依赖性VLDL结合/摄取是否主要由SDC-1完成。目的3是排除LRP1参与VLDL的滋养细胞内在化。 AIM 4是在Epplant培养中测量Placenal Villi的VLDL结合/摄取，比较了前美术与单纯怀孕的女性的绒毛。拟议的工作将进一步了解STB对脂蛋白处理的理解，而HSPG在这方面的功能。鉴于lopenal养分运输的重要性至关重要，这项研究具有重要的临床意义。