The Role of Cdk5 in Stroke

Cdk5 在中风中的作用

• 批准号: 8681557
• 负责人: James A Bibb
• 金额: $ 34.43万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8681557
• 关键词: Ablation; Adult; Affect; Behavioral; Binding; Biochemical; Blood coagulation; CDK5 gene; Calpain; Cause of Death; Cells; Cessation of life; Clinical; Clinical Trials; Complex; Coupled; Cytolysis; Data; Functional disorder; Generations; Genetic; Glutamates; Histopathology; Holoenzymes; In Vitro; Infarction; Injury; Ischemic Penumbra; Ischemic Stroke; Knowledge; Lead; Link; Mediating; Membrane; Middle Cerebral Artery Occlusion; Minority; Modeling; Morbidity - disease rate; Mus; N-Methyl-D-Aspartate Receptors; NMDA receptor antagonist; Nervous System Physiology; Nervous System Trauma; Neurons; Neuroprotective Agents; Outcome; Patients; Pattern; Peptide Hydrolases; Peptides; Phosphotransferases; Physiological; Protein Kinase; Recovery; Role; Severities; Signal Transduction; Specificity; Stroke; Substrate Specificity; Testing; Time; Translating; Viral; alternative treatment; artery occlusion; brain tissue; cofactor; defined contribution; disability; excitotoxicity; functional disability; improved; insight; mortality; neuroprotection; neurotoxicity; novel; novel strategies; prevent; protein protein interaction; receptor function; response; therapy development; translational study

DESCRIPTION (provided by applicant): Stroke is the leading cause of adult disability in the U.S. and the third leading cause of mortality world-wide. The most common form, ischemic stoke, is caused by blood clots occluding arterial supply, resulting in permanent neurological damage or death. For a minority of patients, blood clots can be removed or lysed to prevent or limit stroke injury. However, neuroprotectants that improve survival and recovery are not available. Following arterial occlusion, neuronal death spreads outward from the initial infarct as neurons depolarize causing massive glutamate release and hyperactivation of NMDA receptors (NMDAR). As a result, excitotoxic Ca2+ flows into cells where it activates the protease calpain. This excitotoxic cascade is a major component of stroke pathophysiology. However, efforts to block the cascade with NMDAR antagonists have not proven effective in clinical trials due to unwanted effects. We discovered that the protein kinase Cdk5 physically links calpain to the NR2B subunit of NMDARs. Cdk5 is also bound to its activator p35. Through this NR2B-calpain- Cdk5/p35 signaling complex, excitotoxic activation of NMDARs causes calpain to convert p35 to p25. Cdk5 associated with p25 causes neuronal death and has been suggested to mediate to ischemic injury. However little is yet known of how Cdk5 or p35/p25 contributes to stroke pathophysiology or how it may be effectively targeted to improve outcome. Here we propose to characterize the dysregulation of Cdk5 following middle cerebral artery occlusion (MCAO) and determine the neuroprotective effects of loss of Cdk5 or p35 in mice. As a novel strategy to achieve neuroprotection we will target the NR2B-calpain-Cdk5/p35 cascade by identifying functional protein-protein interaction motifs and developing small interfering peptides (SIPs) that prevent calpain-Cdk5 and NR2B-Cdk5 interactions. These SIPs will be optimized as molecules that potently and specifically dissociate the NR2B-calpain-Cdk5/p35 and prevent Cdk5/p25 generation by NMDAR hyperactivation without otherwise affecting the functions of the receptors, calpain, or Cdk5. We will then assess their ability to neuroprotect and improve behavioral and histological outcome in mice subjected to MCAO. These translational studies will advance our knowledge of the mechanisms that mediate stroke injury and derive novel neuroprotectants that will potentially lead to the development of therapies that improving recovery and reduce stroke-related disability.

描述（由申请人提供）：中风是美国成人残疾的主要原因，也是全球第三大死亡原因。最常见的形式是缺血性中风，是由血栓阻塞动脉供应引起的，导致永久性神经损伤或死亡。对于少数患者，可以去除或溶解血栓以预防或限制中风损伤。然而，尚无能够改善生存和恢复的神经保护剂。动脉闭塞后，神经元死亡从最初的梗塞向外扩散，如下所示 神经元去极化导致大量谷氨酸释放和 NMDA 受体 (NMDAR) 过度激活。结果，兴奋毒性 Ca2+ 流入细胞，激活蛋白酶钙蛋白酶。这种兴奋性毒性级联是中风病理生理学的主要组成部分。然而，由于不良反应，用 NMDAR 拮抗剂阻断级联的努力在临床试验中并未被证明有效。我们发现蛋白激酶 Cdk5 将钙蛋白酶与 NMDAR 的 NR2B 亚基物理连接。 Cdk5 也与其激活剂 p35 结合。通过这种 NR2B-钙蛋白酶-Cdk5/p35 信号复合物，NMDAR 的兴奋毒性激活导致钙蛋白酶将 p35 转化为 p25。与 p25 相关的 Cdk5 会导致神经元死亡，并被认为可以介导缺血性损伤。然而，人们对 Cdk5 或 p35/p25 如何促进中风病理生理学或如何有效靶向改善预后尚知之甚少。在这里，我们建议描述大脑中动脉闭塞（MCAO）后 Cdk5 失调的特征，并确定 Cdk5 或 p35 缺失对小鼠的神经保护作用。作为实现神经保护的新策略，我们将通过识别功能性蛋白质-蛋白质相互作用基序并开发小干扰肽（SIP）来靶向 NR2B-钙蛋白酶-Cdk5/p35 级联。 防止钙蛋白酶-Cdk5 和 NR2B-Cdk5 相互作用。这些 SIP 将被优化为有效且特异性地解离 NR2B-钙蛋白酶-Cdk5/p35 并防止 NMDAR 过度激活产生 Cdk5/p25 的分子，而不会影响受体、钙蛋白酶或 Cdk5 的功能。然后，我们将评估它们对接受 MCAO 的小鼠进行神经保护和改善行为和组织学结果的能力。这些转化研究将增进我们对介导中风损伤机制的了解，并衍生出新型神经保护剂，从而有可能开发出改善康复和减少中风相关残疾的疗法。