A zebrafish model to investigate beta-cell functional maturation and heterogeneity

研究β细胞功能成熟和异质性的斑马鱼模型

• 批准号: RGPIN-2017-04106
• 负责人: Kieffer, Timothy
• 金额: $ 2.48万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=685162
• 关键词: zebrafish; model; investigate; beta; cell

-cells are a small population of highly specialized endocrine cells in the pancreas that produce insulin, a hormone required for survival and key to the proper regulation of energy homeostasis. While there is an increasing appreciation that there exists considerable -cell heterogeneity, our understanding of the basis and significance of this heterogeneity, along with the factors guiding -cell maturation, remain poorly understood. ******Zebrafish provide an excellent model to elucidate the molecular mechanisms underlying the development and maturation of -cells. From a genetic and physiological perspective, zebrafish are surprisingly similar to humans. Indeed, all organs and cells involved in controlling mammalian metabolism are present in these fish. They are also readily amenable to genetic engineering to generate novel lines of fish to permit sophisticated probing of the function of genes, proteins and cells. A particularly useful aspect of using zebrafish as a model organism is the fact that they develop very rapidly. Moreover, the embryos are remarkably transparent, a characteristic that makes them ideal to study vertebrate development. Therefore, with zebrafish we can visualize the entire process of -cell development, as well as monitor -cell functional maturation, in real time in a living organism. ******Our overall goal is to delineate the molecular pathways underlying the maturation of insulin-secreting cells, and to investigate -cell heterogeneity from a developmental and physiological perspective. This will be achieved by the following three specific objectives:******Objective 1: To delineate -cell functional maturation in zebrafish. We will use a novel zebrafish transgenic line which allows visualization of -cell stimulus-secretion coupling in vivo. ******Objective 2: To determine whether the different lineages of -cells arising during pancreas development contribute to -cell heterogeneity in the adult zebrafish pancreas. One of our main hypotheses is that -cells are composed of different sub-populations which are specialized either to secrete insulin in response to nutrients or proliferate when tissue damage occurs. To investigate this aspect, we will use a novel zebrafish transgenic line where we can label different -cell populations and follow them through the entire life of the fish to assess their specific genetic profile and function.******Objective 3: To delineate the contribution of nutrient sensing to -cell functional maturation. How zebrafish -cells sense nutrients and coordinate responses to stimuli has not been investigated. We will use genetic tools combined with live imaging approaches to probe the key components essential to proper nutrient sensing.******Collectively, this unprecedented depth of -cell characterization will provide a deeper understanding of -cell biology and the molecular mechanisms that control -cell development, maturation and function.

胰岛β细胞是胰腺中一小群高度特化的内分泌细胞，它们产生胰岛素，胰岛素是生存所需的激素，是正确调节能量稳态的关键。虽然越来越多的人认识到存在相当大的细胞异质性，但我们对这种异质性的基础和意义的理解，以及沿着引导细胞成熟的因素，仍然知之甚少。****** 斑马鱼提供了一个很好的模型来阐明细胞发育和成熟的分子机制。从遗传学和生理学的角度来看，斑马鱼与人类惊人地相似。事实上，所有参与控制哺乳动物新陈代谢的器官和细胞都存在于这些鱼中。它们也很容易接受基因工程，以产生新的鱼类品系，从而允许对基因、蛋白质和细胞的功能进行复杂的探测。使用斑马鱼作为模式生物的一个特别有用的方面是它们发育非常迅速。此外，这些胚胎非常透明，这一特性使它们成为研究脊椎动物发育的理想材料。因此，利用斑马鱼，我们可以在活体中真实的实时观察细胞发育的整个过程，并监测细胞功能的成熟。** 我们的总体目标是描绘胰岛素分泌细胞成熟的分子途径，并从发育和生理的角度研究细胞异质性。这将通过以下三个具体目标来实现：** 目标1：描述斑马鱼的细胞功能成熟。我们将使用一种新的斑马鱼转基因系，它允许可视化的细胞刺激分泌耦合在体内。** 目的2：确定胰腺发育过程中出现的不同谱系的β细胞是否有助于成年斑马鱼胰腺中β细胞的异质性。我们的一个主要假设是，细胞是由不同的亚群组成的，这些亚群要么专门分泌胰岛素以响应营养素，要么在组织损伤发生时增殖。为了研究这方面，我们将使用一种新的斑马鱼转基因系，在那里我们可以标记不同的细胞群，并在鱼的整个生命周期中跟踪它们，以评估它们的特定遗传特征和功能。目的3：阐明营养感受对细胞功能成熟的贡献.斑马鱼的细胞如何感知营养和协调对刺激的反应还没有被研究过。我们将使用遗传工具与实时成像方法相结合，以探测适当营养感测所必需的关键成分。总的来说，这一前所未有的深入的非细胞特性将提供一个更深入的了解非细胞生物学和分子机制，控制非细胞的发展，成熟和功能。