Molecular Pathways of Programmed Cell Death And Viral Cytopathicity

程序性细胞死亡和病毒细胞病变的分子途径

基本信息

批准号：
8745344
负责人：
michael j lenardo
金额：
$ 27.93万
依托单位：
NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
依托单位国家：
美国
项目类别：
财政年份：
资助国家：
美国
起止时间：
至
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/8745344
关键词：
Acquired Immunodeficiency Syndrome Antioxidants Apoptosis Apoptotic Autophagocytosis BNIP3L gene Brain Cardiac Cardiac Myocytes Cell Death Cell Surface Receptors Cell Survival Cell physiology Cells Cellular Morphology Cellular Stress Cessation of life Complex Cytoplasmic Organelle Cytoplasmic Protein DICER1 gene Data Diagnosis Digestion Disease Drosophila genus Embryo Energy-Generating Resources Equilibrium Exhibits Family Fibroblasts Genes Genetic Genetic Programming Goals HIV Heart Host Defense Human Immune Immune response Infectious Agent Injury Investigation Ischemia Knockout Mice Lead Lymphocyte Lysosomes Mediating Mediator of activation protein Membrane MicroRNAs Mitochondria Mitochondrial Proteins Modeling Molecular Morbidity - disease rate Morphology Mus Mutation Myocardial Infarction Necrosis Nerve Neurodegenerative Disorders Organ Outcome PTEN-induced putative kinase Parkinson Disease Pathogenesis Pathway interactions Pattern Peptide Hydrolases Phosphoglycerate Mutase Phosphotransferases Physiological Play Process Protein Serine/Threonine Phosphatase Proteins RIPK3 gene Receptor Signaling Recruitment Activity Regulation Regulator Genes Reperfusion Injury Reperfusion Therapy Reporting Role Severe Acute Respiratory Syndrome Severities Signal Pathway Stroke TNFRSF1A gene TNFRSF6 gene Tumor Necrosis Factor Receptor Vesicle Viral Virus Virus Diseases Wild Type Mouse Work Yeasts cancer cell caspase-8 cell growth regulation cell injury cell type improved in vivo insight interest member mortality nuclear factor 1 nuclease oxidative damage palliative paralogous gene phosphoglycerate preference presenilin programs receptor response rhomboid transcription factor ubiquitin-protein ligase

项目摘要

Internal death programs play significant roles in many diseases. Pathogenic effects can result from inefficient cell death or from inappropriate or excessive death such as that caused by the human immunodeficiency virus (HIV) during AIDS or the SAR-CoV virus during SARS. In this project, we are taking a multifaceted approach to studying molecular mechanisms of both apoptotic and nonapoptotic death programs in lymphocytes as well as other cell types. A major focus of our investigations are death-inducing cell surface receptors in the tumor necrosis factor receptor (TNFR) superfamily such as TNFR1 and CD95/Fas/APO-1. Both receptors play an important role in stimulating both apoptotic and nonapoptotic death of cells principally in immune processes. Little is known about how these alternative death pathways are entrained to receptor signaling. Interestingly, both receptors can have effects beside death such as the induction of transcription factors. We are trying to understand how these receptors stimulate the intracellular machinery that causes cell death in preference to other cellular outcomes. We have discovered that inhibition of caspase-8 in non-lymphoid cells can lead to another form of cell death exhibiting particular cytoplasmic double membrane structures called autophagy. Autophagy is an evolutionarily conserved process from humans to yeast by which cytoplasmic proteins and organelles are catabolized but very little was known about results at the end of autophagy when cells were selecting between autophagic cell death and survival. Mitochondria have a primary physiological role in producing ATP as an energy source, but also regulate cell death. In response to cellular stress, dysfunctional mitochondria produce ROS and other pro-death mediators to initiate programmed cell death pathways, like apoptosis or necropotosis. Mitophagy, a selective form of autophagy, can target dysfunctional mitochondria for lysosomal degradation and protect cells from oxidative damage. This is beneficial for the survival of terminally differentiated cells, like nerve and heart muscle cells. Several regulators of mitophagy, including PINK1, Nix (BNIP3L), and PARKIN have been identified. Mutations or deletions of those genes have been related with a variety of diseases, including ischemia injury in myocardial infarction and stroke, as well as neurodegenerative disease. Hence, understanding the detailed mechanism of mitophagy remains an important goal for improving the diagnosis and treatment of diseases involving mitochondria. Two autosomal recessive Parkinsons disease genes, PINK1 (PTEN induced putative kinase 1) and PARKIN, regulate mitophagic clearance of dysfunctional mitochondria. In healthy cells, PINK1 is constitutively degraded by mitochondrial proteases, such as mitochondria inner membrane protease Presenilin Associated, Rhomboid-Like (PARL) protein. Membrane depolarization of dysfunctional mitochondria inhibits PINK1 degradation, causing it to accumulate and promote mitophagy via recruitment of another familial Parkinson's protein, the E3 ubiquitin ligase PARKIN. However, the detailed mechanism of PINK1 degradation and stabilization remains unclear. We have studyPGAM5, paralog member 5 of a family of highly conserved phosphoglycerate mutases, a 32-kDa mitochondrial protein that apparently lacks phosphotransfer function on phosphoglycerates, but retains activity as a serine/threonine protein phosphatase that regulates the ASK1 kinase. The functions of PGAM5 are complex since it also serves as an anti-oxidant regulator in the Kelch ECH associating protein 1-nuclear factor-E2-related factor 2 (KEAP1-NRF2) signaling pathway (19, 20). Recently, PGAM5 was found as a downstream mitochondrial target of RIP3 in the necrosis pathway in cancer cells, by recruiting the RIP1-RIP3-MLKL necrosis "attack" complex to mitochondria (3, 21). Interestingly, PGAM5 has also been reported as a genetic suppressor of PINK1 in Drosophila (22), as well as a substrate of PARL (23). Thus, it is important to establish the in vivo role of PGAM5 involving mitochondria. using a new strain of knockout mice, we found that PGAM5 is critical for PINK1 stabilization on damaged mitochondria to initiate mitophagy since loss of PGAM5 totally disables PINK1 stabilization. Cells deficient with PGAM5 showed elevated ROS originated from mitochondria, and exacerbated cell necrosis compared to control wild type cells. In stroke and cardiac ischemic-reperfusion injury models, PGAM5-deficient mice showed significantly increased severity of injuries in the brain and heart compared to wild-type mice, indicating that PGAM5 protects against ischemia-reperfusion-induced necrosis. Taken together, our data suggest that PGAM5 promotes PINK1-mediated mitophagy, which could be cytoprotective in ischemic injuries. Moreover, PGAM5 also provides a functional linkage between malfunction of mitophagy and the pathogenesis of necrosis.

内部死亡计划在许多疾病中起着重要作用。致病作用可能是由于细胞死亡效率低下或不适当或过度死亡所致，例如在SARS期间由人类免疫缺陷病毒（HIV）或SAR-COV病毒引起的。在这个项目中，我们正在采用多方面的方法来研究淋巴细胞以及其他细胞类型中凋亡和非凋亡死亡程序的分子机制。我们研究的主要重点是肿瘤坏死因子受体（TNFR）超家族中诱导死亡的细胞表面受体，例如TNFR1和CD95/FAS/APO-1。两种受体在刺激细胞的凋亡和非凋亡死亡中都起着重要作用，主要是在免疫过程中。关于这些替代死亡途径如何涉及受体信号传导，知之甚少。有趣的是，两种受体除死亡以外的作用，例如转录因子的诱导。我们正在尝试了解这些受体如何刺激偏爱其他细胞结局的细胞内机械。我们发现，非淋巴细胞中caspase-8的抑制作用会导致另一种形式的细胞死亡，表现出特定的细胞质双膜结构，称为自噬。自噬是一个从人到酵母的进化保守的过程，通过该过程，细胞质蛋白和细胞器被分解代谢，但是当细胞在自噬细胞死亡和生存之间选择自动噬时的结果时，对结果知之甚少。线粒体在产生ATP作为能源的主要生理作用，但也调节细胞死亡。为了响应细胞应激，功能障碍的线粒体产生ROS和其他促死亡介质来启动编程的细胞死亡途径，例如凋亡或坏死病。线粒体是一种自噬的一种选择性形式，可以靶向功能障碍的线粒体用于溶酶体降解，并保护细胞免受氧化损伤。这对终末分化细胞（如神经和心肌细胞）的存活是有益的。已经确定了几个线粒体调节剂，包括Pink1，Nix（BNIP3L）和Parkin。这些基因的突变或缺失与多种疾病有关，包括心肌梗塞和中风中的缺血损伤以及神经退行性疾病。因此，了解线粒体的详细机制仍然是改善涉及线粒体疾病的诊断和治疗的重要目标。两个常染色体隐性帕金森氏病基因PINK1（PTEN诱导的激酶1）和Parkin调节线粒体功能障碍的线粒体清除。在健康细胞中，PINK1由线粒体蛋白酶（例如线粒体内膜蛋白酶presenilin，Rhomboid-like（PARL）蛋白）组成降解。功能障碍线粒体的膜去极化抑制了PINK1降解，从而通过募集另一种家族性帕金森氏蛋白E3泛素连接酶Parkin来累积和促进线粒体。然而，PINK1降解和稳定的详细机制尚不清楚。我们有一个高度保守的磷酸甘油酸突变酶的StudyPGAM5，旁系同源构件5，这是一种32 kDa的线粒体蛋白，显然缺乏在磷酸甘油酸酯上的磷酸转移功能，但将活性保留为丝氨酸/三氨酸蛋白磷酸酶，可调节ASK1 kINase。 PGAM5的功能很复杂，因为它也用作Kelch Ech相关蛋白1-核因子-E2相关因子2（KEAP1-NRF2）信号通路的抗氧化调节剂（19，20）。最近，通过募集RIP1-RIP3-MLKL坏死“攻击”复合物，发现PGAM5是癌细胞中RIP3的下游线粒体靶标（3，21）。有趣的是，PGAM5也据报道是果蝇中PINK1的遗传抑制剂（22），以及PARL的底物（23）。因此，重要的是建立涉及线粒体的PGAM5的体内作用。使用新的敲除小鼠菌株，我们发现PGAM5对于在受损的线粒体上稳定粉红色至关重要，以启动线粒体，因为PGAM5的损失完全可以禁用PINK1稳定。缺乏PGAM5的细胞显示ROS升高起源于线粒体，与对照野生型细胞相比，细胞坏死加剧。与野生型小鼠相比，在中风和心脏缺血性灌注损伤模型中，PGAM5缺陷型小鼠的脑和心脏损伤严重程度显着增加，这表明PGAM5可防止抑制缺血性抑制诱导的坏死诱导的坏死。综上所述，我们的数据表明PGAM5促进了PINK1介导的线粒体，这可能在缺血性损伤中具有细胞保护作用。此外，PGAM5还提供了线粒体功能障碍与坏死发病机理之间的功能联系。