Megakaryocyte and platelet ontogeny

巨核细胞和血小板个体发育

• 批准号: 8829970
• 负责人: James Palis
• 金额: $ 5.17万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2018-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8829970
• 关键词: Activities of Daily Living; Adult; Agonist; Biological Assay; Blood Cells; Blood Platelet Disorders; Blood Platelets; CDKN1C gene; Cell Cycle; Cell Therapy; Cell surface; Cells; Characteristics; Coagulation Process; Collaborations; Cytoplasmic Granules; Development; Down-Regulation; Embryo; Embryonic Development; Embryonic Structures; Erythrocytes; Erythroid; F2R gene; Family; Family member; Foundations; Generations; Growth; Health; Hematopoietic; Hematopoietic stem cells; Hemorrhage; Hemostatic function; Human; Immunity; In Vitro; Inflammation; Light; Mediating; Megakaryocytes; Megakaryocytopoieses; Mus; Natural History; Neonatal; P-Selectin; Platelet Activation; Platelet Count measurement; Property; Radial; Relative (related person); Replacement Therapy; Research; Role; Signal Transduction; Source; Specific qualifier value; Structure; Testing; Thrombin; Thrombocytopenia; Thrombopoiesis; Thrombus; Transcript; Up-Regulation; angiogenesis; base; blastomere structure; embryonic stem cell; fetal; high risk; in vivo; induced pluripotent stem cell; inhibitor/antagonist; neonate; response; stem; transcription factor

DESCRIPTION (provided by applicant): Platelets are anucleate cells derived from megakaryocytes (megs) that serve as critical components of hemostasis and thrombus formation, and mediate aspects of inflammation, immunity, and angiogenesis. In the adult, all platelets are derived from hematopoietic stem cells (HSCs). We previously discovered in the mouse embryo that the meg lineage is specified several days before HSC emergence as embryonic (pre- HSC) megakaryopoiesis. We have also determined that embryonic megs have limited polyploidization and generate extremely large platelets with small a-granules. Thrombopoiesis in human neonates is also characterized by limited polyploidization and rapid cytoplasmic maturation. Endoreplication is regulated in part by the Cip/Kip family of cell cycle inhibitors. Our preliminary studies indicate that embryonic, but not adult, platelets express high levels of p57 (Kip2). In Aim 1, we will further define the differences between embryonic, fetal and adult megakaryopoiesis and test the hypothesis that differences in meg endoreplication are regulated, in part, by the differential expression of Cip/Kip family members. Our preliminary studies of primary embryonic platelets indicate that they are effectively activated by thrombin but markedly less so by ADP. These functional studies correlate with the differential upregulation of PAR1 and down-regulation of P2Y12 in primary embryonic versus adult platelets. In Aim 2 studies, we will test the hypothesis that embryonic platelets have intrinsic functional differences in activation and clot formation when compared to their adult counterparts. An understanding of hematopoietic ontogeny is particularly relevant to the generation of blood cells from embryonic stem (ES) cells and induced pluripotent stem (iPS) cells, which carry the potential to serve as an important source of cell-based therapies. We hypothesize that ES cell-derived megs and platelets will have predominantly embryonic characteristics. This hypothesis will be tested by comparing ES cell-derived meg maturation and platelet function with that of primary embryonic cells. This proposed research builds upon our studies of meg ontogeny and platelet emergence in the murine embryo and establishes a foundation for the development of clinically useful cell-based therapies from ES/iPS cell sources.

描述（由申请人提供）：血小板是源自巨核细胞（MEGS）的核酸细胞，它们是止血和血栓形成的关键成分，并介导炎症，免疫和血管生成的各个方面。在成年人中，所有血小板均来自造血干细胞（HSC）。我们以前在小鼠胚胎中发现，在HSC出现前几天指定了MEG谱系为胚胎（hsc）巨核菌素。我们还确定胚胎MEG具有有限的多倍体化，并产生具有小A颗粒的极大血小板。人类新生儿中的血小板疾病也以有限的多倍体化和快速的细胞质成熟为特征。内存由CIP/KIP家族的细胞周期抑制剂家族调节。我们的初步研究表明，胚胎（但不是成年）血小板表达高水平的p57（KIP2）。在AIM 1中，我们将进一步定义胚胎，胎儿和成人巨核酸的差异，并检验以下假设：MEG内存的差异部分通过CIP/KIP家族成员的差异表达来调节。我们对原发性胚胎血小板的初步研究表明，它们被凝血酶有效激活，但 ADP明显较少。这些功能研究与原代胚胎与成人血小板中PAR1的差异上调和P2Y12的下调相关。在AIM 2研究中，我们将测试胚胎血小板具有内在功能差异的假设 与成年对应物相比，在激活和凝块形成中。对造血本体发育的理解特别与胚胎干细胞（ES）细胞和诱导多能干（IPS）细胞的血细胞产生特别相关，这些细胞具有作为基于细胞疗法的重要来源的潜力。我们假设ES细胞衍生的MEGS和血小板将主要具有胚胎特征。该假设将通过将ES衍生的MEG成熟和血小板功能与原代胚胎细胞的功能进行比较。这项拟议的研究基于我们对鼠类胚胎中MEG个体发育和血小板出现的研究，并为从ES/IPS细胞来源开发基于临床有用的基于细胞的疗法的基础。