KINASE-MEDIATED SIGNALING PATHWAYS IN NEURONAL APOPTOSIS

神经元凋亡中激酶介导的信号通路

• 批准号: 6394540
• 负责人: MARY LOU VALLANO
• 金额: $ 26.48万
• 依托单位: UPSTATE MEDICAL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2004-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6394540
• 关键词: apoptosis; biological signal transduction; calcium flux; genetically modified animals; granule cell; laboratory mouse; neurotrophic factors; phosphorylation; protein kinase; tissue /cell culture; transcription factor

DESCRIPTION (From the applicant's abstract): We are studying the kinase-mediated signaling pathways that promote neuronal survival and prevent apoptosis in primary cultures of granule neurons. Relevant neurotrophins are insulin-like growth factor (IGF-1) and brain-derived neurotrophic factor (BDNF). Glutamate is the predominant neurotransmitter that regulates neuronal activity through its interaction with different glutamate receptor-channels, referred to herein as N-methyl-D-aspartate (NMDA) and non-NMDA receptors. Binding of these agents to their respective receptors in the neuronal plasma membrane initiates activation of intracellular signaling cascades that regulate the transcription of pro-apoptotic or anti-apoptotic genes. The balance between these gene products ultimately determines cell fate. Early in granule cell development, before neurons have formed synaptic connections, they rely exclusively on neurotrophic factors, present in the serum that bathes them, for survival. We have novel evidence that particular isoforms of the family of phospholipid-sensitive protein kinases (PKCs), designated as atypical PKCs (aPKCs), are critical components of the neurotrophin-dependent survival pathway. We are quite enthusiastic about these data since almost nothing is currently known about the neuronal functions of aPKCs. Moreover, preliminary data indicate that inhibition of aPKCs reduces phosphorylation on serine-133 of the nuclear transcription factor CREB. One goal of this application is to extend our studies examining the linkage between neurotrophin-dependent activation of aPKCs. phosphorvlation of CREB. and survival. In many neuronal populations, inadequate electrical stimulation by excitatory neurotransmitters or inadequate trophic factor make cell death more likely. A "Ca2+ set-point hypothesis" postulates that the bulk cytosolic Ca2+ activity determines the degree to which immature neurons require trophic factor to suppress the mechanism responsible for apoptosis (Koike et al., 1989). Accordingly, many types of neurons grown in dissociated culture can be rescued from death, induced by neurotrophin deprivation, by inclusion of agents in the media that produce a sustained elevation in Ca2+. These agents include elevated KCI acting through voltage-sensitive Ca2+ channels (VSCCs) and NMDA acting directly upon NMDA receptor channels (NRs). We have novel evidence that a Ca2+ and calmodulin-dependent kinase, designated as CaM KIV, and its substrate CREB are critical components of this Ca2+-dependent signaling pathway. Immunocytochemical evidence also indicated that these treatments induce the redistribution of CaM KIV from the nucleus to the cytosol. A second goal of this application is to extend our studies examining the linkage between calcium, CaM KIV phosphorvlation of CREB, and survival. Phosphorylation and activation of CREB may mediate induction of anti-apoptotic genes, such as bc1-2, or repression of pro-apoptotic genes, such as bax. A third goal in this application is to compare the expression levels of bc1-2 and bax rnRNAs under culture conditions promoting survival or apoptosis.

描述（来自申请人的摘要）：我们正在研究 激酶介导的信号通路，促进神经元存活并防止 原代培养的颗粒神经元凋亡。相关的神经营养因子是 胰岛素样生长因子（IGF-1）和脑源性神经营养因子 （BDNF）。谷氨酸是调节神经元的主要神经递质， 活性通过其与不同的谷氨酸受体通道的相互作用， 本文中称为N-甲基-D-天冬氨酸（NMDA）和非NMDA受体。 这些药物与神经元血浆中各自受体的结合 膜启动细胞内信号级联的激活， 促凋亡或抗凋亡基因的转录。之间的平衡 这些基因产物最终决定了细胞的命运。颗粒细胞早期 在发育过程中，在神经元形成突触连接之前， 只依赖于神经营养因子，存在于沐浴它们的血清中， 生存我们有新的证据表明， 磷脂敏感性蛋白激酶（PKCs），称为非典型PKCs 蛋白激酶C（aPKCs）是神经营养因子依赖性存活的关键组分。 通路我们对这些数据非常感兴趣，因为几乎没有什么是 目前已知aPKC的神经元功能。此外，初步 数据表明，抑制aPKC可降低 核转录因子CREB。此应用程序的一个目标是 扩展我们的研究，检查神经营养素依赖性 激活aPKC。CREB的磷酸化。和生存在许多神经元 人群，兴奋性神经递质的电刺激不足 或营养因子不足使细胞更可能死亡。A“Ca 2+设定点 “假设”假定大量的胞质Ca 2+活性决定了 未成熟神经元需要营养因子来抑制神经元生长的程度。 负责细胞凋亡的机制（Koike等人，1989年）。因此，许多 在分离培养物中生长的神经元类型可以免于死亡， 通过在培养基中加入 使钙离子持续升高。这些药剂包括升高的KCl作用 通过电压敏感性Ca 2+通道（VSCC）和NMDA直接作用于 NMDA受体通道（NR）。我们有新的证据表明， 钙调蛋白依赖性激酶，命名为CaM KIV，及其底物CREB， 这一Ca 2+依赖性信号通路的重要组成部分。 免疫细胞化学证据还表明，这些处理诱导了 CaM KIV从细胞核到细胞质的再分布。第二个目标是 这个应用是为了扩展我们的研究， 钙、CREB的CaM KIV磷酸化和存活。磷酸化和 CREB的激活可以介导抗凋亡基因的诱导，例如 bc 1 -2，或抑制促凋亡基因，如bax。第三个目标是 应用是比较bc 1 -2和bax rnRNAs在不同条件下的表达水平。 促进存活或凋亡的培养条件。