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有效的多价配体，以影响成年神经干细胞（NSC）和 基于仿生策略的人类多能干细胞（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的多价结合开始，从而导致受体聚类。但是，目前非常有限，控制多价交互的能力并调节生活系统内的关键信号事件。虽然已经实现了抗体诱导的配体或受体聚类，但该方法并非受控，有效或容易再现。可以通过重复诱导型二聚体结构域的小分子依赖性二聚化来聚类，但是这种方法涉及过表达融合蛋白，并且不容易适用于内源配体或受体。合成多价配体的使用是一种控制和阐明细胞信号中基本机制的有前途的方法。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命运，它们既可以用作强大的生物学工具，又可以用作 作为有效的治疗学。拟议工作的第一个目的是利用多价晶状体结合物来研究以弗氏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策的机制。在此目标中，我们将进行结构功能 Ephrin信号传导和干细胞分化中的多价性分析，以及基于工程肽的多价配体，用于在体外和体内有效激活Eph-磷信号传导。我们的第二个目的是确定是否可以设计多价结合物来激活NSC中的Wnt信号，这将通过基于工程肽的多价配体的组合来实现，并在体外和体内表征其信号传导性能。我们预计所产生的多价ephrin和Wnt配体将作为控制干细胞命运决策的有效生物活性材料，这对于干细胞和体外生物学的机械研究也很重要，同时也是如此 至于应用程序，包括增强的细胞培养系统，药理学和毒理学筛查以及恢复器官功能的再生医学方法。