Mechanisms of placental dysfunction in pregnancy malaria

妊娠期疟疾胎盘功能障碍的机制

• 批准号: 9109935
• 负责人: ANDREW V OLEINIKOV
• 金额: $ 22.43万
• 依托单位: FLORIDA ATLANTIC UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-02-01 至 2018-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9109935
• 关键词: Adaptor Signaling Protein; Adhesions; Affect; Antibodies; Antimalarials; Binding; Biochemical; Biological; Biological Assay; Blood; Carrier Proteins; Cell Line; Cells; Cessation of life; Child; Clinical; Development; Embryonic Development; Erythrocytes; Event; Fetal Growth; Fetal Growth Retardation; Fetus; Fluorescence Microscopy; Formalin; Functional disorder; Future; Genes; Genetic Transcription; Growth and Development function; Homeostasis; Hormones; Human; Immune response; Immunofluorescence Microscopy; In Vitro; Infant Mortality; Infiltration; Inflammation; Intervention; Knock-out; LDL-Receptor Related Protein 2; Ligands; Lipids; Low Birth Weight Infant; Malaria; Maternal-Fetal Exchange; Mediating; Methods; Modeling; Molecular; Mothers; Mus; Nutrient; Pathology; Pathway interactions; Perinatal mortality demographics; Pharmaceutical Preparations; Placenta; Plasmodium falciparum; Play; Polymerase Chain Reaction; Pregnancy; Pregnant Women; Process; Protease Inhibitor; Proteins; Reverse Transcription; Role; Sampling; Signal Transduction; Supplementation; Surface; Syncytiotrophoblast; System; Testing; Time; Tissues; Villous; Vitamins; Woman; abortion; base; cytotrophoblast; fetal; in vitro Model; in vivo; infant morbidity/mortality; intrinsic factor-cobalamin receptor; macrophage; malaria infection; placental malaria; placental transfer; prevent; protein expression; protein function; public health relevance; receptor; research study; response; stillbirth; trafficking; wasting

 DESCRIPTION (provided by applicant): Pregnancy malaria (PM) caused by Plasmodium falciparum contributes to about 150,000 child and 10,000 mother deaths annually in malaria endemic regions. Infant mortality in PM is largely due to low birth weight (LBW); however PM also causes stillbirth and abortion. LBW is associated with parasitized erythrocyte (PE) sequestration and consequent inflammation in the placenta; however, the precise molecular details of maternal- fetal interactions in PM and placental changes leading to fetal growth restriction/LBW are still poorly understood. The long-term purpose of this project is to clarify molecular details of these processes. This project will focus on the role of megalin-associated multi-ligand scavenging and signal transduction system, which is highly expressed in placental syncytiotrophoblast. This system may mediate and regulate a substantial amount of maternofetal exchange and homeostasis of vitamins, lipids, hormones, Ca2+, matrix proteases and inhibitors, and other carrier proteins, including receptor cubilin and its ligands. The megalin system plays an extremely important role in embryonic development and murine knock-out of megalin or its intracellular adaptor protein Dab2 leads to 98% perinatal mortality. We hypothesize that PM disturbs megalin function/expression/distribution in syncytiotrophoblast which, in turn, may contribute significantly to the placental pathology due to the high importance of the molecules, handled by this receptor, for normal fetal growth/development. Our preliminary results strongly support this hypothesis. To understand the role of the megalin system in maternal-fetal interactions and in placental pathology during PM we suggest the following Specific Aims: 1) Analyze abundance of megalin system proteins in placental sections from malaria endemic regions and relate it to PM pathology using antibodies against megalin, cubilin, and Dab2 and immunofluorescence microscopy assay (IFA), as well as reverse transcription-PCR approach; 2) Study the effect of parasitized erythrocyte (PE) adhesion to the villous cytotrophoblast BeWo cells on megalin system protein expression, trafficking, ligand transfer, and signal transduction. We will use real time fluorescence microscopy, IFA, RT-PCR, biochemical and cell biological approaches. We will also test whether the addition of human macrophages to PE bound on the surface of BeWo cells may affect these processes thus modeling the initial steps of the innate immune response before the development of an adaptive response in primigravida women, most susceptible to PM pathology. These experiments will test our hypothesis about potential role of proteins of the megalin transporting/signaling system in the placental transfer of nutrients and regulatory molecules, and association of their abundance/distribution with PM and/or with LBW. This, in turn, will create a basis for future expanded studies of maternofetal exchange, pathological changes, and mechanisms of fetal growth restriction/LBW related to megalin functions in PM, a substantial contributor to infant mortality and morbidity in malaria endemic regions.

 描述（由申请人提供）：在疟疾流行地区，由恶性疟原虫引起的妊娠期疟疾 (PM) 每年导致约 150,000 名儿童和 10,000 名母亲死亡。 PM 中的婴儿死亡率主要是由于低出生体重 (LBW)；然而PM也会导致死产和流产。 LBW 与寄生红细胞 (PE) 隔离和随后的胎盘炎症有关；然而，对于导致胎儿生长受限/低出生体重的母胎相互作用和胎盘变化的精确分子细节仍知之甚少。该项目的长期目的是阐明这些过程的分子细节。该项目将重点研究巨蛋白相关多配体清除和信号转导系统的作用，该系统在胎盘合体滋养层中高度表达。该系统可以介导和调节大量的母体胎儿交换和维生素、脂质、激素、Ca2+、基质蛋白酶和抑制剂以及其他载体蛋白（包括受体cubilin及其配体）的稳态。巨蛋白 系统在胚胎发育中起着极其重要的作用，敲除巨蛋白或其细胞内接头蛋白Dab2的小鼠导致98%的围产期死亡率。我们假设 PM 干扰合体滋养层中的巨蛋白功能/表达/分布，这反过来可能对胎盘病理学产生重大影响，因为由该受体处理的分子对于正常胎儿生长/发育非常重要。我们的初步结果有力地支持了这一假设。为了了解巨蛋白系统在母婴相互作用和 PM 期间胎盘病理学中的作用，我们建议以下具体目标：1) 分析疟疾流行地区胎盘切片中巨蛋白系统蛋白的丰度，并使用针对巨蛋白、cubilin 和 Dab2 的抗体和免疫荧光显微镜测定 (IFA) 以及反向分析将其与 PM 病理学联系起来。 转录-PCR方法； 2）研究寄生红细胞（PE）粘附到绒毛细胞滋养层BeWo细胞对巨蛋白系统蛋白表达、运输、配体转移和信号转导的影响。我们将使用实时荧光显微镜、IFA、RT-PCR、生化和细胞生物学方法。我们还将测试将人类巨噬细胞添加到 BeWo 细胞表面结合的 PE 中是否会影响这些过程，从而模拟最容易受到 PM 病理影响的初产妇在适应性反应发展之前先天免疫反应的初始步骤。这些实验将检验我们的假设，即巨蛋白转运/信号系统蛋白在营养物质和调节分子的胎盘转移中的潜在作用，以及它们的丰度/分布与 PM 和/或 LBW 的关联。反过来，这将为未来扩大母胎交换、病理变化以及与 PM 中巨蛋白功能相关的胎儿生长受限/LBW 机制奠定基础，PM 是疟疾流行地区婴儿死亡率和发病率的重要因素。