Multivalent Ligands to Control Stem Cell Fate

控制干细胞命运的多价配体

• 批准号: 8762257
• 负责人: Ravi S. Kane
• 金额: $ 34.24万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2019-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8762257
• 关键词: Adult; Agonist; Antibodies; Binding; Biological; Biology; Biomimetics; Biopolymers; Cell Culture System; Cell Differentiation process; Cell Proliferation; Cell surface; Cells; Chemistry; Chimeric Proteins; Complex; Development; Developmental Biology; Dimerization; Engineering; Ephrin-B1; Ephrin-B2; Ephrins; Event; Extracellular Matrix; Hippocampus (Brain); Human; In Vitro; Integral Membrane Protein; Investigation; Learning; Life; Ligand Binding; Ligands; Mediating; Medicine; Memory; Methods; Modeling; Neuroglia; Neurologic; Neuronal Differentiation; Neurons; Organ; Organism; Parkinson Disease; Peptides; Phage Display; Pharmacologic Substance; Pharmacology and Toxicology; Pluripotent Stem Cells; Post-Translational Protein Processing; Process; Property; Public Health; Receptor Cell; Recombinants; Regenerative Medicine; Replacement Therapy; Research; Science; Signal Pathway; Signal Transduction; Stem cells; Structure; System; Therapeutic; Time; Wnt proteins; Work; base; cell behavior; design; dopaminergic neuron; human disease; human embryonic stem cell; in vivo; induced pluripotent stem cell; mood regulation; nerve stem cell; neurogenesis; overexpression; polypeptide; public health relevance; receptor; small molecule; stem cell differentiation; stem cell fate; tool

DESCRIPTION (provided by applicant): The objective of the proposed work is to design potent multivalent ligands that influence the differentiation of adult neural stem cells (NSCs) and human pluripotent stem cells (hPSCs) based on a biomimetic strategy - multivalency. Cellular signal transduction can often begin with the multivalent binding of ligands, either secreted or cell-surface tethered, to target cell receptors, leading to receptor clustering. The capacity to control multivalent interactions and thereby modulate key signaling events within living systems is, however, currently very limited. While antibody-induced ligand or receptor clustering has been achieved, this method is not well- controlled, efficient, or readily reproducible. Intracellulr targets can be clustered by the small-molecule dependent dimerization of repeated inducible dimerizing domains, but this approach involves overexpressing fusion proteins and is not readily applicable for endogenous ligands or receptors. The use of synthetic multivalent ligands is a promising approach to control and to elucidate fundamental mechanisms in cellular signaling. If such multivalent ligands could be designed to activate key signaling pathways and thereby control stem cell fate in vitro and in vivo, they could serve as both powerful biological tools and as potent therapeutics. The first aim of the proposed work is to harness multivalent ephrin conjugates to study mechanisms by which Eph-ephrin signaling regulates cell fate decisions in neural stem cells and pluripotent stem cells. Within this aim, we will conduct a structure-function analysis of ephrin multivalency in signaling and stem cell differentiation, as well as engineer peptide-based multivalent ligands for potent activation of Eph-ephrin signaling in vitro and in vivo. Our second aim is to determine whether multivalent conjugates can be engineered to activate Wnt signaling in NSCs, which will be achieved with a combination of engineering peptide-based multivalent ligands and characterizing their signaling properties in vitro and in vivo. We anticipate that the resulting multivalent ephrin and Wnt ligands will serve as potent bioactive materials for controlling stem cell fate decisions, a capability that would be significan for mechanistic investigations in stem cell and developmental biology in vitro and in vivo, as well as for applications including enhanced cell culture systems, pharmacology and toxicology screens, and regenerative medicine approaches to restore organ function.

描述（由申请人提供）：拟议工作的目的是设计影响成体神经干细胞（NSC）分化和 基于仿生策略——多价性的人类多能干细胞（hPSC）。细胞信号转导通常可以从分泌的或细胞表面束缚的配体与靶细胞受体的多价结合开始，从而导致受体聚集。然而，控制多价相互作用并从而调节生命系统内关键信号事件的能力目前非常有限。虽然已经实现了抗体诱导的配体或受体聚类，但该方法不能很好地控制、有效或容易重现。细胞内靶标可以通过重复诱导二聚化结构域的小分子依赖性二聚化来聚集，但这种方法涉及过度表达融合蛋白，并且不容易适用于内源配体或受体。使用合成多价配体是控制和阐明细胞信号传导基本机制的一种有前途的方法。如果可以设计这种多价配体来激活关键信号通路，从而在体外和体内控制干细胞的命运，那么它们既可以作为强大的生物工具， 作为有效的治疗方法。拟议工作的第一个目标是利用多价肝配蛋白缀合物来研究肝配蛋白信号传导调节神经干细胞和多能干细胞中细胞命运决定的机制。在此目标下，我们将进行结构-功能 分析肝配蛋白在信号传导和干细胞分化中的多价性，以及设计基于肽的多价配体以在体外和体内有效激活肝配蛋白信号传导。我们的第二个目标是确定是否可以设计多价缀合物来激活 NSC 中的 Wnt 信号传导，这将通过结合工程化基于肽的多价配体并表征其体外和体内信号传导特性来实现。我们预计由此产生的多价肝配蛋白和 Wnt 配体将作为控制干细胞命运决定的有效生物活性材料，这种能力对于体外和体内干细胞和发育生物学的机制研究也具有重要意义 其应用包括增强细胞培养系统、药理学和毒理学筛选以及恢复器官功能的再生医学方法。