The Role of Cdk5 in Stroke

Cdk5 在中风中的作用

• 批准号: 9418253
• 负责人: James A Bibb
• 金额: $ 23.51万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-01-27 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9418253
• 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; Data; Functional disorder; Generations; Genetic; Glutamates; Histologic; Histopathology; Holoenzymes; Hyperactive behavior; In Vitro; Infarction; Injury; Intravenous; 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; improved outcome; insight; mortality; neuron loss; neuroprotection; neurotoxicity; novel; novel strategies; prevent; protein protein interaction; receptor function; response; stroke treatment; 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，也是全球死亡率的第三大主要原因。最常见的形式是缺血性stoke，是由堵塞动脉供应的血凝块引起的，导致永久性神经系统损害或死亡。对于少数患者，可以去除或裂解血块以防止或限制中风损伤。但是，没有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为 神经元去极化，导致大规模谷氨酸释放和NMDA受体（NMDAR）的过度激活。结果，兴奋性Ca2+流入细胞中激活蛋白酶钙蛋白酶。这种兴奋性毒性级联反应是中风病理生理学的主要组成部分。但是，由于不必要的影响，在临床试验中尚未证明与NMDAR拮抗剂阻止级联反应的努力尚未证明有效。我们发现蛋白激酶CDK5实际将钙蛋白酶与NMDAR的NR2B亚基联系起来。 CDK5也与其激活剂p35结合。通过这种NR2B-calpain- CDK5/p35信号传导复合物，NMDAR的兴奋性激活使Calpain将P35转换为P25。与P25相关的CDK5会导致神经元死亡，并被建议介导缺血性损伤。然而，鲜为人知的是CDK5或p35/p25如何对中风病理生理学有效，或者如何有效地靶向改善预后。在这里，我们提出表征脑动脉闭塞后CDK5的失调（MCAO），并确定小鼠中CDK5或p35丢失的神经保护作用。作为实现神经保护作用的一种新型策略，我们将通过鉴定功能性蛋白质 - 蛋白质相互作用基序并发展出小的干扰肽（SIP）来瞄准NR2B-Calpain-CDK5/p35级联 预防钙蛋白酶-CDK5和NR2B-CDK5相互作用。这些SIP将被优化为有力，特异性地解离NR2B-Calpain-CDK5/p35的分子，并通过NMDAR过度激活来防止CDK5/p25产生CDK5/P25，而不会另外影响受体的功能，CALPAIN和CDK5。然后，我们将评估他们在经历MCAO的小鼠中神经保护和改善行为和组织学结果的能力。这些翻译研究将提高我们对介导中风损伤的机制的了解，并得出新颖的神经保护剂，这些神经保护剂有可能导致改善恢复并减少与中风相关的残疾的疗法的发展。