Metabolic control of systemic autoimmunity

全身自身免疫的代谢控制

• 批准号: 7758380
• 负责人: Andras Perl
• 金额: $ 31.09万
• 依托单位: UPSTATE MEDICAL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-02-01 至 2013-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7758380
• 关键词: ATP Synthesis Pathway; Accounting; Activities of Daily Living; Address; Apoptosis; Autoimmunity; Biogenesis; Candidate Disease Gene; Cell Death; Cells; Cessation of life; Consultations; Critiques; Data; Defect; Disease; Electron Transport; Exhibits; Figs - dietary; Gene Expression; Genes; Glutathione; Hydroxychloroquine; In Vitro; Inflammation; Inherited; Laboratories; Lupus; Maps; Measures; Membrane Potentials; Metabolic; Metabolic Control; Metabolic Pathway; Mitochondria; Mitochondrial DNA; Mitochondrial Proteins; Molecular; Necrosis; Nitric Oxide; Nuclear; Pathology; Pathway interactions; Patients; Pharmaceutical Preparations; Phase; Phosphorylation; Prednisone; Process; Production; Protein Biosynthesis; Proteins; Publications; Published Comment; RNA; Recording of previous events; Role; SOD2 gene; Signal Transduction; Sirolimus; Stream; Systemic Lupus Erythematosus; T-Cell Activation; T-Lymphocyte; Tacrolimus Binding Protein 1A; Testing; Transaldolase; Transfer RNA; Voltage-Dependent_Anion_Channel-1; Western Blotting; Work; Writing; base; innovation; mitochondrial dysfunction; monocyte; mycophenolate mofetil; rRNA Genes; reactive oxygen intermediate; receptor; sensor; small hairpin RNA; stem

DESCRIPTION (provided by applicant): Systemic lupus erythematosus (SLE) is characterized by abnormal T-cell activation and death, processes which are crucially dependent on the controlled production of reactive oxygen intermediates (ROI) and of ATP in mitochondria. The mitochondrial transmembrane potential has conclusively emerged as a critical checkpoint of ATP synthesis and cell death. In normal T cells, we firstly identified the elevation of the mitochondrial transmembrane potential, i.e., mitochondrial hyperpolarization (MHP), and, secondly, also ATP depletion, which are early and reversible steps of T-cell activation and apoptosis. Conversely, in SLE patients, we found that T cells exhibit persistent MHP as well as ATP and glutathione depletion which decrease activation-induced apoptosis and instead predispose T cells for necrosis, thus stimulating inflammation in SLE. Therefore, determining the molecular basis and consequences of persistent MHP is essential for understanding the mechanism of altered activation and death signaling in lupus T cells. We found persistent MHP to be associated with increased mitochondrial mass and increased mitochondrial and cytoplasmic Ca2+ content in T lymphocytes and also with enhanced nitric oxide (NO) production in monocytes. NO-induced mitochondrial biogenesis in normal T cells accelerates the rapid phase and reduces the plateau of Ca2+ influx upon CD3/CD28 costimulation, thus mimicking the Ca2+ signaling profile of lupus T cells. Since mitochondria are major Ca2+ stores, NO-dependent mitochondrial biogenesis may account for altered Ca2+ handling. In lupus T cells, we identified changes in expression of genes that control key metabolic pathways: over-expression of transaldolase (TAL) which induces glutathione depletion and MHP, low expression of eNOS-interacting protein (NOSIP) that regulates compartmentalized production of NO, and over-expression of the rapamycin receptor FKBP12. We observed improvement of disease activity, normalization of CD3/CD28-induced Ca2+ fluxing, and persistence of MHP in rapamycin-treated patients, suggesting that altered Ca2+ fluxing is downstream or independent of mitochondrial dysfunction. The proposed studies will test the hypothesis that inhibition of the electron transport chain via S-nitrosylation stemming from glutathione depletion in the presence of NO causes persistent MHP which, in turn, activates the mammalian target of rapamcyin (mTOR) pathway. First, we will measure functional capacity of the electron transport chain in isolated mitochondria and determine the role of GSH depletion and TAL activation in MHP and ATP depletion of lupus T cells. Second, we will determine the role of intrinsic and extrinsic NO production, compartmentalized expression of eNOS, and responsiveness to NO. Third, we will examine the role of mTOR as a sensor and down-stream effector of MHP and controller of increased Ca2+ fluxing. Fourth, we will systematically map metabolic checkpoints upstream and downstream of MHP and validate the involvement of candidate genes that can be targeted to normalize T-cell activation in SLE.

描述（由申请人提供）：全身性红斑红血病（SLE）的特征是异常T细胞激活和死亡，至关重要的过程取决于线粒体中的活性氧中间体（ROI）的受控产生和ATP的产生。线粒体跨膜电位已最终作为ATP合成和细胞死亡的关键检查点。在正常的T细胞中，我们首先确定了线粒体跨膜电位的升高，即线粒体超极化（MHP），其次，也是ATP耗竭，这是T细胞活化和凋亡的早期和可逆步骤。相反，在SLE患者中，我们发现T细胞表现出持久的MHP以及ATP和谷胱甘肽耗竭，可减少激活诱导的细胞凋亡，而倾向于诱发T细胞因坏死，从而刺激SLE的炎症。因此，确定持久性MHP的分子基础和后果对于理解狼疮T细胞中激活和死亡信号传导的机制至关重要。 我们发现持续的MHP与T淋巴细胞中的线粒体质量增加，线粒体和细胞质Ca2+含量增加以及单核细胞中一氧化氮（NO）的产生增强有关。正常T细胞中未诱导的线粒体生物发生会加速快速相位，并在CD3/CD28共刺激下降低了Ca2+流入的高原，从而模仿了狼疮T细胞的Ca2+信号传导曲线。由于线粒体是主要的Ca2+存储，因此无依赖性的线粒体生物发生可能会解释Ca2+处理的改变。在狼疮T细胞中，我们确定了控制关键代谢途径的基因表达的变化：跨层溶解酶（TAL）的过表达，诱导谷胱甘肽耗竭和MHP，eNOS相互作用蛋白（NOSIP）的低表达，这些eNos-Contracting蛋白（NOSIP）调节了NO，过表达的NO，过表达Rapamyccin Coptors Fkkpp12。我们观察到疾病活性的改善，CD3/CD28诱导的Ca2+通量的归一化以及在雷帕霉素治疗的患者中MHP的持久性，这表明Ca2+通量改变的变化是下游或独立于线粒体功能障碍的。 拟议的研究将检验以下假设：在存在无谷胱甘肽的情况下，由于谷胱甘肽耗竭而抑制电子传输链，无需持续的MHP，这反过来又激活了Rapamcyin（MTOR）途径的哺乳动物靶标。首先，我们将测量电子传输链在分离的线粒体中的功能能力，并确定GSH耗竭和TAL激活在MHP和ATP T细胞中的ATP耗竭中的作用。其次，我们将确定固有和外在的NO生产，分隔的eNOS表达以及对NO的响应能力的作用。第三，我们将研究MTOR作为MHP的传感器和下游效应子的作用，以及CA2+通量增加的控制器。第四，我们将系统地绘制MHP上游和下游的代谢检查点，并验证候选基因的参与，这些基因可以针对SLE中的T细胞激活标准化。