DNA repair promotes stroke recovery

DNA修复促进中风康复

• 批准号: 9285256
• 负责人: Ruth ANNE Stetler
• 金额: $ 35.07万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9285256
• 关键词: Alpha Cell; Animals; Axon; Base Excision Repairs; Behavioral; Biological Preservation; Brain; Cell Death; Cell Survival; Cells; Cerebral Ischemia; Cessation of life; Clinical; Coculture Techniques; Cognitive deficits; DNA Damage; DNA Repair; DNA Repair Endonuclease; DNA-(apurinic or apyrimidinic site) lyase; DNA-Directed DNA Polymerase; Data; Demyelinations; Electrophysiology (science); Enzymes; Failure; Fostering; Gender; Genes; Glucose; Impairment; In Vitro; Injury; Ischemia; Knock-out; Knockout Mice; Knowledge; Lead; Left; Lesion; Ligase; Mediating; Mus; Neurologic; Neurological outcome; Neurons; Oligodendroglia; Outcome; Oxygen; Pathogenesis; Pathology; Pathway interactions; Patients; Peptides; Performance; Permeability; Pharmacology; Phosphorylation; Point Mutation; Process; Protein Isoforms; Protein Kinase C; Proteins; Rattus; Recovery; Recovery of Function; Regulation; Research; Resistance; Role; Site; Stroke; Subfamily lentivirinae; System; Testing; Therapeutic; Therapeutic Intervention; Tissues; Transfection; Transgenic Organisms; Transient Cerebral Ischemia; Up-Regulation; aged; base; cerebral ischemic injury; cognitive performance; deprivation; improved; in vivo; inhibitor/antagonist; knock-down; mutant; myelination; neurological recovery; neuron loss; neurotransmission; new therapeutic target; novel; oligodendrocyte precursor; overexpression; oxidative DNA damage; post stroke; pre-clinical; precursor cell; protein expression; relating to nervous system; remyelination; repair enzyme; repaired; response; small hairpin RNA; stroke recovery; white matter; white matter damage; white matter injury

Project Summary DNA damage and repair are critical components to ischemic injury and recovery. DNA base excision repair (BER) is the primary pathway activated in the brain to repair oxidative lesions that predominate following cerebral ischemic injury. BER proceeds via the sequential coordination of repair enzymes, but most notably centers on the activity of AP endonuclease-1 (APE1). APE1 not only functions to remove the prominent AP sites that occur in oxidatively damaged DNA but also coordinates and stimulates the activity of other BER proteins. Ongoing studies are implicating a role of BER DNA repair in ischemic recovery, but these have focused primarily on neurons. White matter injury is a major cause of long-term sensorimotor and cognitive deficits following stroke. The recovery of white matter following ischemic injury necessitates either the survival of existing oligodendrocytes or repair of demyelinated axons via axonal regrowth and oligodendrogenesis to fully rebuild neuronal connectivity and functional axonal signal conduction. Therapeutic strategies to promote white matter recovery following ischemic injury may lead to improved long-term recovery in stroke patients. We have exciting preliminary data to demonstrate that DNA damage readily occurs in ischemic white matter, and that APE1 is critical to functional recovery of white matter following stroke. Furthermore, we have discovered that PKCζ negatively regulates the repair activity of APE1, giving us a powerful new target for therapeutic intervention aimed at bolstering BER following ischemic injury. These data support the novel hypothesis that bolstering DNA repair, and APE1 in particular, by PKCζ inhibition is critical for white matter survival and functional recovery following focal cerebral ischemic injury. Using our novel conditional APE1 knockout mouse, transgenic rats overexpressing APE1 and APE1 point mutations, and neuronal/oligodendrocytic co-cultures, this project will 1) examine the role of APE1 and DNA repair in oligodendrocytic death and white matter integrity following ischemic injury, and 2) determine the extent of ischemic protection afforded by inhibiting the phosphorylation of APE1 by PKCζ. This project will significantly advance the understanding of the pathogenesis of white matter damage following cerebral ischemic injury, and explore a translatable approach to improving DNA repair activity via administration of a cell-permeable PCKζ inhibitor.

项目摘要 DNA损伤和修复是缺血性损伤和恢复的关键组成部分。DNA碱基切除修复 (BER)是大脑中激活的修复氧化损伤的主要途径， 脑缺血损伤BER通过修复酶的顺序协调进行，但最值得注意的是， AP内切核酸酶-1（APE 1）的活性。APE 1不仅可以去除突出的AP 这些位点发生在氧化损伤的DNA中，但也协调和刺激其他BER的活性。 proteins.正在进行的研究暗示BER DNA修复在缺血性恢复中的作用，但这些研究表明， 主要研究神经元。白色物质损伤是长期感觉运动和认知障碍的主要原因 中风后的缺陷。缺血性损伤后白色物质的恢复需要存活 或通过轴突再生和少突胶质细胞发生修复脱髓鞘轴突， 完全重建神经元连接和功能性轴突信号传导。治疗策略，以促进 缺血性损伤后的白色物质恢复可改善卒中患者的长期恢复。我们 有令人兴奋的初步数据表明，DNA损伤容易发生在缺血性白色物质中， APE 1对中风后白色物质的功能恢复至关重要。此外，我们还发现 PKC β负调节APE 1的修复活性，这为我们提供了一个强大的新靶点， 旨在支持缺血性损伤后BER的干预。这些数据支持了一个新的假设， 通过PKC β抑制来支持DNA修复，特别是APE 1，对白色物质存活至关重要， 局灶性脑缺血损伤后的功能恢复。使用我们的新型条件性APE 1敲除小鼠， 过表达APE 1和APE 1点突变的转基因大鼠，以及神经元/少突胶质细胞共培养物， 该项目将1）研究APE 1和DNA修复在少突胶质细胞死亡和白色物质中的作用 缺血性损伤后的完整性，和2）确定通过抑制缺血性损伤后的缺血性保护的程度。 APE 1通过PKC β的磷酸化。该项目将大大促进对 脑缺血损伤后白色损害的发病机制，并探讨一种可翻译的方法 涉及通过施用细胞可渗透的PCK β抑制剂来改善DNA修复活性。