EARLY INCREASE IN MATRIX METALLOPROTEINASE ACTIVITY IN NEURONAL NUCLEUS

神经元核中基质金属蛋白酶活性的早期增加

• 批准号: 8167447
• 负责人: YI YANG
• 金额: $ 24.1万
• 依托单位: UNIVERSITY OF NEW MEXICO
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-03-01 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8167447
• 关键词: Attenuated; Base Excision Repairs; Blood - brain barrier anatomy; Brain; Cell Death; Cell Nucleus; Cessation of life; Cleaved cell; Complement; Computer Retrieval of Information on Scientific Projects Database; DNA; DNA Repair; DNA Repair Enzymes; Data; Extracellular Protein; Funding; Gelatinase A; Gelatinase B; Gelatinases; Grant; In Vitro; Infarction; Institution; Ischemia; Link; Matrix Metalloproteinase Inhibitor; Matrix Metalloproteinases; Neurons; Nuclear; Nuclear Matrix; Permeability; Proteolysis; Rattus; Recovery; Reperfusion Therapy; Research; Research Personnel; Resources; Role; Single Strand Break Repair; Site; Small Interfering RNA; Source; Stroke; Techniques; United States National Institutes of Health; XRCC1 gene; base; behavior test; brain cell; improved; in vivo; neuronal survival; novel; oxidative DNA damage; repair enzyme; repaired; Attenuated; Base Excision Repairs; Blood - brain barrier anatomy; Brain; Cell Death; Cell Nucleus; Cessation of life; Cleaved cell; Complement; Computer Retrieval of Information on Scientific Projects Database; DNA; DNA Repair; DNA Repair Enzymes; Data; Extracellular Protein; Funding; Gelatinase A; Gelatinase B; Gelatinases; Grant; In Vitro; Infarction; Institution; Ischemia; Link; Matrix Metalloproteinase Inhibitor; Matrix Metalloproteinases; Neurons; Nuclear; Nuclear Matrix; Permeability; Proteolysis; Rattus; Recovery; Reperfusion Therapy; Research; Research Personnel; Resources; Role; Single Strand Break Repair; Site; Small Interfering RNA; Source; Stroke; Techniques; United States National Institutes of Health; XRCC1 gene; base; behavior test; brain cell; improved; in vivo; neuronal survival; novel; oxidative DNA damage; repair enzyme; repaired

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Aims and results: Matrix metalloproteinases (MMPs) have been linked to blood-brain barrier opening and neuronal death associated with ischemia. Although best known for their role in the proteolysis of extracellular protein targets, recent studies have revealed that MMPs are also localized to various intracellular sites including nucleus. We previously found increased active gelatinases (MMP-2/-9) in ischemic neuronal nuclei during early reperfusion. Intranuclear MMP-2 degraded nuclear DNA repair enzymes PARP-1 and XRCC1, suggesting a role for MMP-2 in nuclear matrix proteolysis and DNA repair after stroke. DNA base excision repair (BER) machinery is the main mechanism in neuronal nuclei to repair oxidized DNA. During BER and single strand break repair, PARP-1 is activated by DNA breaks and triggers XRCC1 recruitment to damage sites where it participates in BER. Our preliminary data showed that treatment with MMP inhibitor significantly attenuated accumulation of oxidized DNA bases in nuclei of ischemic rat brain neurons at 3 hrs reperfusion. Based on this finding, we propose a novel Hypothesis that activation of MMPs in the ischemic neuronal nucleus may degrade DNA repair enzymes and contribute to accumulation of oxidized DNA bases which trigger cell death in neurons. This project is focused on following studies: 1) Investigate the expression of other MMPs (MMP-9 and -3) in neurons and determine if they are capable of cleaving PARPs and nuclear BER enzymes. 2) Begin to investigate whether the degradation of PARPs and other BER enzymes contributes to accumulation of oxidative DNA damages and delayed neuronal death. In this aim, we also plan to determine if the inhibitors of MMPs can block the cleavage of PARPs and BER enzymes, and thereby improve survival of brain cells and be beneficial in recovery after ischemic insult. Infarct size, blood-brain barrier (BBB) permeability, and behavior test after stroke will be evaulated. 3) Set up primary neuron culture studies with OGD conditions. MMP-2 siRNA techniques will be employed in primary neuron cultures to investigate the roles of MMP-2 in DNA repair and neuronal survival following OGD. The in vitro study in this aim is to complement the in vivo studies above.

该副本是利用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这不一定是调查员的机构。 目标和结果： 基质金属蛋白酶（MMP）已与与缺血有关的血脑屏障开口和神经元死亡有关。 尽管最近以其在细胞外蛋白靶标的蛋白水解中的作用而闻名，但最近的研究表明，MMP也位于包括核在内的各种细胞内部位。我们先前在早期再灌注期间发现了缺血性神经元核中活性明胶酶（MMP-2/-9）的增加。 核内MMP-2降解的核DNA修复酶PARP-1和XRCC1，表明MMP-2在中风后核基质蛋白水解和DNA修复中起作用。 DNA碱基切除修复（BER）机械是修复氧化DNA的神经元核的主要机制。在BER和单链断裂修复过程中，PARP-1被DNA断裂激活，并触发XRCC1募集到参与BER的损坏位点。我们的初步数据表明，用MMP抑制剂的治疗显着减弱了3小时再灌注时缺血大鼠脑神经元核中氧化DNA碱基的积累。基于这一发现，我们提出了一个新的假设，即缺血神经元核中MMP的激活可能降解DNA修复酶，并有助于氧化DNA碱基的积累，这会触发神经元中细胞死亡的氧化DNA碱基。该项目的重点是以下研究：1）研究神经元中其他MMP（MMP -9和-3）的表达，并确定它们是否能够切割PARP和核BER酶。 2）开始研究PARP和其他BER酶的降解是否有助于氧化DNA损伤的积累和延迟神经元死亡。在此目标中，我们还计划确定MMP的抑制剂是否可以阻止PARP和BER酶的裂解，从而改善脑细胞的存活，并在缺血性损伤后恢复。梗塞大小，血脑屏障（BBB）的渗透性和中风后的行为测试将被避免。 3）在OGD条件下建立原发性神经元培养研究。 MMP-2 siRNA技术将用于原代神经元培养物，以研究MMP-2在OGD后MMP-2在DNA修复和神经元存活中的作用。 该目的的体外研究是补充上述体内研究。