Role of TRPM7 and TRPM2 Channels in Neuronal Development and Regeneration

TRPM7 和 TRPM2 通道在神经元发育和再生中的作用

基本信息

批准号：
RGPIN-2016-04574
负责人：
Sun, HongShuo
金额：
$ 2.26万
依托单位：
University of Toronto
依托单位国家：
加拿大
项目类别：
Discovery Grants Program - Individual
财政年份：
2020
资助国家：
加拿大
起止时间：
2020-01-01 至 2021-12-31
项目状态：
已结题

来源：
https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=709380
关键词：
Role TRPM7 TRPM2 Channels Neuronal

项目摘要

Neurons are highly specialized cells that form the basic functional units in brain circuitry, and proper development of neuronal structure and circuitry is essential for normal function of the brain. We propose to investigate the role of Transient Receptor Potential (TRP) channels in neuronal development and regeneration with specific interest in TRPM7 and its closely related TRPM2 channels. TRPM7 and TRPM2 are non-selective cation channels permeable to Ca2+ and play an important role in various physiological functions, including cell survival and proliferation. TRPM7 knockout (KO) is embryonic lethal. However, we have shown that TRPM7 channels are expressed in the brain, and inhibiting these channels increases neuronal survival to hypoxia (Sun lab, Mol Brain 2015, 8:11) and ischemia (Sun et al., Nat Neurosci 2009; 12:1300-7), both in vitro and in vivo. The paradox is that expression of TRPM7 is required for embryonic development, but inhibition or suppression of TRPM7 prevents hypoxia-induced neuronal cell death in neonates and ischemia-induced neuronal cell death in adults. This leads to our postulating that TRPM7 plays a critical role in neuronal development and regeneration by differentially regulating Ca2+ homeostasis under normoxic and hypoxic conditions. However, how TRPM7 is involved in neuronal development and regeneration has not been fully investigated. Because neuronal development and regeneration depends on a critical Ca2+ window, I hypothesize that the TRPM7 channel is an essential protein regulating Ca2+ levels that are, in turn, needed for neuronal development and regeneration under normal and hypoxic conditions via differential downstream signal pathways. Conversely, inhibition of TRPM7 may promote neuronal cell proliferation, survival, outgrowth and regeneration. The requisite suitable tools and reagents include selective TRPM7 and TRPM2 inhibitors, siRNA, CRISPR (TRPM7 construct), antibodies, TRPM2 knockout (KO) mice (viable), and TRPM7 kinase KO, as well as inducible KO mice for both TRPM7 and TRPM2 (under development) available to my lab. Together with my extensive experience in TRPM7, we propose the following three short-term projects and one long-term project over the next five years: 1) Explore the role of TRPM7 and TRPM2 in neuronal outgrowth, maturation and synapse formation in normoxic and hypoxic conditions. 2) Determine the signal pathways involved in the TRPM7 and TRPM2 channels mediated neuronal development and maturation in brain neurons in normoxic and hypoxic conditions. 3) Evaluate the role of TRPM7 and TRPM2 in neuronal regeneration in vitro and in vivo. Our long-term project is to evaluate the role of TRPM7 and TRPM2 in neuronal regeneration. Significance: This work will contribute to our knowledge of the TRP channels in the field of neuronal development and regeneration, and our research will have tangible benefits for HQP development.

神经元是高度特化的细胞，形成大脑回路的基本功能单元，神经元结构和回路的正确发育对于大脑的正常功能至关重要。我们建议研究瞬时受体电位 (TRP) 通道在神经元发育和再生中的作用，特别关注 TRPM7 及其密切相关的 TRPM2 通道。 TRPM7和TRPM2是Ca2+可渗透的非选择性阳离子通道，在细胞存活和增殖等多种生理功能中发挥重要作用。 TRPM7 敲除 (KO) 是胚胎致死的。然而，我们已经证明 TRPM7 通道在大脑中表达，抑制这些通道会增加神经元在缺氧（Sun lab, Mol Brain 2015, 8:11）和缺血（Sun et al., Nat Neurosci 2009; 12:1300）下的存活率-7)，体外和体内。矛盾的是TRPM7的表达是胚胎发育所必需的，但抑制TRPM7可以防止新生儿缺氧诱导的神经元细胞死亡和成人缺血诱导的神经元细胞死亡。这导致我们假设 TRPM7 通过在常氧和缺氧条件下差异调节 Ca2+ 稳态，在神经元发育和再生中发挥关键作用。然而，TRPM7如何参与神经元发育和再生尚未得到充分研究。由于神经元发育和再生依赖于关键的 Ca2+ 窗口，我假设 TRPM7 通道是调节 Ca2+ 水平的重要蛋白质，反过来，在正常和缺氧条件下，通过差异下游信号通路，神经元发育和再生需要 TRPM7 通道。相反，TRPM7 的抑制可能促进神经元细胞增殖、存活、生长和再生。必要的合适工具和试剂包括选择性 TRPM7 和 TRPM2 抑制剂、siRNA、CRISPR（TRPM7 构建体）、抗体、TRPM2 敲除 (KO) 小鼠（活的）和 TRPM7 激酶 KO，以及 TRPM7 和 TRPM2 的诱导型 KO 小鼠（正在开发中）可供我的实验室使用。结合我在 TRPM7 中的丰富经验，我们在未来五年提出以下三个短期项目和一个长期项目： 1) 探索TRPM7和TRPM2在常氧和缺氧条件下神经元生长、成熟和突触形成中的作用。 2)确定常氧和缺氧条件下TRPM7和TRPM2通道介导的脑神经元发育和成熟所涉及的信号通路。 3)评估TRPM7和TRPM2在体外和体内神经元再生中的作用。我们的长期项目是评估 TRPM7 和 TRPM2 在神经元再生中的作用。意义：这项工作将有助于我们对神经元发育和再生领域的 TRP 通道的了解，并且我们的研究将为 HQP 的发展带来切实的好处。