Peroxiredoxin 6 and Cataractogenesis

过氧化还原蛋白 6 和白内障发生

• 批准号: 7372897
• 负责人: DHIRENDRA P SINGH
• 金额: $ 37.13万
• 依托单位: UNIVERSITY OF NEBRASKA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7372897
• 关键词: Actins; Age; Aging; Antioxidants; Apoptosis; Attenuated; Binding; Biological; Biological Assay; Biological Markers; Biological Models; Blindness; Calpain; Cataract; Cell Aging; Cell Survival; Cells; Combined Modality Therapy; Crystalline Lens; Data; Degenerative Disorder; Disease; Elements; Environment; Epithelial Cells; Etiology; Event; Exhibits; Eye diseases; Figs - dietary; Foundations; Functional disorder; Gene Expression; Genes; Genetic Transcription; Goals; Growth Factor; In Vitro; Knockout Mice; Lead; Letters; Measurement; Mediating; Membrane; Modeling; Molecular; Monitor; Mus; NF-kappa B; Nuclear Extract; Organ; Oxidation-Reduction; Oxidative Stress; Paraquat; Peroxidases; Phospholipase A2; Play; Process; Proteins; Rattus; Reactive Oxygen Species; Recombinants; Regulation; Reporting; Repression; Role; Signal Transduction; Site; Site-Directed Mutagenesis; Smooth Muscle Actin Staining Method; Stress; System; Techniques; Testing; Therapeutic; Therapeutic Uses; Time; Tissues; Transactivation; Transfection; age related; aged; antioxidant therapy; attenuation; base; cell age; cell injury; clinical application; feeding; in vivo; insight; interest; lens; normal aging; novel; peroxiredoxin; prevent; promoter; research study; sound

DESCRIPTION (provided by applicant): Recent evidence implicates that the oxidative stress plays a role in the etiology of Age-Related Cataract, and suggests that aged lens cells are prone to this damage due to reduced expression of antioxidants. Because ocular lens is constantly exposed to environmental stress, it continuously generates reactive oxygen species (ROS), if not removed, increased formation and local accumulation of ROS in the cellular microenvironment causes lens cell damage-by initiating wide-spectrum of deleterious signaling and if this situation prolongs may lead to cataractogenesis. Peroxiredoxin 6 (PRDX6), a 'moonlighting protein' with both GSH peroxidase and aiPLA2 (acidic Ca2+independent phospholipase A2) activities, is highly expressed in lens. Our studies have shown diminution of PRDX6 expression and higher intracellular ROS levels in lens cells during aging. Using targeted inactivation of Prdx6 gene in mice, we found that Prdx6-depleted lenses and/or lens epithelial cells (LECs) contain elevated levels of ROS and bio-activeTGF21; exhibit phenotypic changes with overmodulation of TGF21 inducible genes such as 1-SM-actin and 2ig-h3, and these genes are implicated in pathophysiology of cataractogenesis. We envisage a vicious feed-forward-process (ROS?? TGF?1??ROS = overmodulation of genes??) taking place within the local microenvironment of aging LECs or LECs facing oxidative stress, and therefore, we hypothesized that by blocking ROS mediated deleterious signaling should reduce progression of cataractogenesis, by interrupting the vicious cycle initiated by locally high levels of ROS and activated TGF21 within cellular microenvironment. We believe that these events are causally related, i.e., that the environmental stress and age-related reduction in PRDX6 in lens tissues leads to ROS-induced damage of membrane or cytosolic factors, as a consequence of this damage, cell homeostatic system fails. The over all goal of this proposal, therefore, is to unveil the roles of oxidative stress in pathophisiology of cataract formation and to show PRDX6 ability in treating/delaying cataractogenesis through three specific aims: 1) Understand the functional significance of PRDX6 and its regulatory role during oxidative stress and aging. 2) Assess the antioxidant potential of PRDX6 in protecting cells facing oxidative stress in vitro and in vivo using TAT-HA- PRDX6 to cargoing PRDX6 protein in Prdx6-/- depleted mice and mice with Paraquat-induced oxidative stress as well as Shumiya cataract rat (SCR), and assess whether cataract progression is slowed by PRDX6. 3) Investigate the regulatory mechanisms of PRDX6 in normal and aging LECs and cells under oxidative stress and define role(s) of downstream redox signaling in controlling its gene transcription. These studies should provide novel insights into the role of oxidative stress in cataract formation and will provide a foundation for rational use of antioxidant based therapeutics for treating or preventing/delaying cataractogenesis. A common disorder of the eye, Age-Related Cataract (ARC) is among the leading causes of blindness. Although evidence suggests a role for reactive oxygen species-driven oxidative stress in the progression and etiology of age-related degenerative diseases including ARC, the mechanism of oxidative stress-induced deleterious signaling, a cause of cellular damage that leads to the disease state, is not clear. Thus clinical application of antioxidant therapy or combination of therapies has been at best equivocal. Using eye lens as a model for age-associated disorders, we will unveil the underlying mechanism involved in the pathophysiology of tissues/organs during oxidative stress or aging. The proposed studies will provide a sound scientific basis for developing an antioxidant-based therapy or combination of therapies for preventing cataractogenesis and age-associated degenerative diseases in general.

描述（由申请人提供）：最近的证据表明，氧化应激在与年龄相关性白内障的病因中起作用，并表明由于抗氧化剂的表达降低，老化的晶状体细胞容易受到这种损害。由于眼镜透镜不断暴露于环境压力，因此它会连续产生活性氧（ROS），如果不去除，在细胞微环境中ROS的形成增加和局部积累会造成透镜细胞损害，从而引发有害信号的广谱，如果这种情况可能会导致造成障碍。过氧蛋白6（PRDX6）是一种具有GSH过氧化物酶和AIPLA2（酸性CA2+独立磷脂酶A2）活性的“月光蛋白质”，在镜头中高度表达。我们的研究表明，衰老过程中晶状体细胞中PRDX6表达和较高的细胞内ROS水平的降低。使用小鼠PRDX6基因的靶向失活，我们发现PRDX6缺失的透镜和/或晶状体上皮细胞（LEC）含有升高的ROS和Bio-ActivetGF21；表现出表型变化，TGF21诱导基因（如1-SM-肌动蛋白和2ig-H3）的过度调制，这些基因与白内生生成的病理生理有关。我们设想在局部微环境中发生的恶性喂养过程（ROS ?? TGF？1 ?? ROS =基因的过度调节？在细胞微环境中。我们认为，这些事件在因果关系上是有因果关系的，即，透镜组织中PRDX6与年龄相关的降低会导致ROS诱导的膜或胞质因子的损害，这是由于这种损害，细胞体内平稳性系统失败了。因此，该提案的所有目标是揭示氧化应激在白内障形成的病理学中的作用，并通过三个特定目标显示PRDX6在治疗/延迟白内术中的能力：1）了解PRDX6的功能意义及其在氧化应激期间的调节作用。 2）评估PRDX6在PRDX6 - / - 耗尽的小鼠中使用Tat-Ha-Prdx6在体外和体内均面对氧化应激的细胞中的抗氧化潜力，并通过paraquat诱导的氧化应激以及shumiya cataract ract（SCREDS）和pRODS（scrdress）是prdx6 - / - 耗尽的小鼠和小鼠。 3）研究在氧化应激下正常和衰老的LEC和细胞中PRDX6的调节机制，并定义下游氧化还原信号在控制其基因转录中的作用。这些研究应提供对氧化应激在白内障形成中作用的新见解，并将为基础使用基于抗氧化剂的治疗剂来治疗或预防/延迟/延迟白内生生成。眼睛，与年龄相关的白内障（ARC）的常见疾病是失明的主要原因之一。尽管有证据表明，活性氧驱动的氧化应激在与年龄相关的退行性疾病（包括ARC）的进展和病因中的作用，包括氧化应激引起的有害信号的机制，这是导致疾病状态的细胞损害的原因，这是导致疾病状态的细胞损害的原因。因此，抗氧化剂治疗或治疗组合的临床应用充其量是模棱两可的。使用眼镜作为年龄相关疾病的模型，我们将在氧化应激或衰老期间揭示组织/器官病理生理学的潜在机制。拟议的研究将为开发基于抗氧化剂的疗法或治疗的结合提供一个合理的科学基础，以防止白内障发生和与年龄相关的退行性疾病。