Endosomal pH regulation in neurons: Roles of Na+/H+ exchangers

神经元内体 pH 调节：Na /H 交换器的作用

• 批准号: RGPIN-2015-06790
• 负责人: Numata, Masayuki
• 金额: $ 2.77万
• 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: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=661076
• 关键词: Endosomal; pH; regulation; neurons; Roles

Endocytosis is a mechanism that internalizes membrane components and receptor-associated ligands through "endosomes", membrane-bound organelles. Upon dissociation of ligands, a large population of receptors returns to the plasma membrane via "recycling endosomes". While it is known that the acidic luminal pH of endosomes plays important roles in ligand-dissociation from the receptor and its degradation, our knowledge of recycling endosomal pH regulation, especially in neurons, is limited. The long-term goal of our research is to define biological roles of endosomal pH in neuronal cells. It is only very recently that researchers have begun to realize that endosomes are functionally more diverse in neurons than in non-neuronal cells, and proteins and lipids are sorted to axons and dendrites through those specialized endosomes. However, how the endosomal diversity is established in neuronal cells remains unknown. We hypothesize that neurons contain more acidic endosomes than non-neuronal cells, which provides a basis for preferential targeting of selected receptors to axons and dendrites. Thus, endosomal pH may add a new mechanistic insight into neuronal communication through the neurotransmitter and its receptor.*** We are going to investigate biological roles of endosomal pH in neurons by using two complementary approaches, one primarily biochemical, the second at the level of the whole organism. As Obj. 1, we will examine the role of endosomal pH in neuronal signaling and receptor targeting that are required for neuronal differentiation. Rat primary cultured neurons will be used for biochemical analyses already used in our laboratory with some modifications. As Obj. 2, we will explore the impact of pH changes in neuronal recycling endosomes on animal behavior using knock-out strains of fruit flies. Fruit flies are used because of the availability of powerful genetic techniques and sensitive behavioral tests. The physiological significance of biochemical interactions of endosomal pH-regulators and their binding partners will be addressed. We anticipate that our research will substantially advance basic understanding of endosomal function in neurons, with general applicability across cognitive science. Our experience in the field, the strong collaborative environment at UBC, access to outstanding trainees, and truly exciting preliminary results uniquely enable us to carry out our research program successfully. I am confident that through this research we will contribute to the Canadian society both through the acquisition of critical base knowledge as well as by training skilled and highly motivated future scientists through our program. The outcome of our research will be published in peer reviewed journals and presented at international conferences.**

内吞作用是一种通过“内体”（膜结合的细胞器）内化膜成分和受体相关的配体的机制。配体解离后，大量受体通过“回收内体”返回质膜。虽然众所周知，内体的酸性腔内pH在受体及其降解中起着重要作用，但我们对回收内体pH调节的了解，尤其是在神经元中，是有限的。我们研究的长期目标是定义内体pH在神经元细胞中的生物学作用。直到最近，研究人员才开始意识到，神经元的内体比非神经元细胞更多样化，并且通过这些专门的内体将蛋白质和脂质分类为轴突和树突。但是，在神经元细胞中如何建立内体多样性仍然未知。我们假设与非神经元细胞相比，神经元含有更多的酸性内体，这为轴突和树突的优先靶向靶向靶向基础。因此，内体pH可以通过神经递质及其受体对神经元通信的新机械洞察。整个生物体。作为obj。 1，我们将检查内体pH在神经元分化所需的神经元信号传导和受体靶向中的作用。大鼠原发性培养的神经元将用于我们实验室中已经使用的生化分析，并进行了一些修改。作为obj。 2，我们将使用果蝇的敲除菌株来探讨神经元回收内体对动物行为的pH变化的影响。由于使用强大的遗传技术和敏感的行为测试，因此使用了果蝇。内体pH调节剂及其结合伴侣的生物化学相互作用的生理意义将得到解决。我们预计，我们的研究将大大提高对神经元内内体功能的基本理解，并具有一般的认知科学适用性。我们在该领域的经验，UBC的强大协作环境，获得出色的学员的访问以及真正令人兴奋的初步结果，使我们能够成功地执行我们的研究计划。我相信，通过这项研究，我们将通过获得关键基础知识以及通过我们的计划培训熟练和高度积极进取的未来科学家来为加拿大社会做出贡献。我们的研究结果将在同行评审期刊上发表，并在国际会议上发表。