Regulation of System xc- by Interleukin-1 beta

描述(申请人提供)：氧化应激是一种有害的条件，当活性氧物种(ROS)的产生和用于中和有毒中间体的细胞防御之间存在失衡，从而使平衡向有利于ROS的方向移动时就会发生。氧化应激与正常衰老和多种老年人疾病有关，包括阿尔茨海默氏症、帕金森氏症和中风。最近，我们的实验室在混合皮质细胞培养中证明了细胞因子白介素1β(IL-1β)--在许多神经系统疾病/障碍中上调--增强了氨基酸转运系统XC的活性，介导了细胞囊泡(E)的增加，细胞囊(E)是三肽抗氧化剂分子谷胱甘肽的组成部分。因此，本提案的目的是阐明IL-1β调节XC系统的细胞、分子和生化机制。在目标1中，研究将确定转运蛋白被调控的一个或多个细胞类型。使用纯神经元和星形胶质细胞培养，以及含有野生型和系统XC缺陷细胞组合的嵌合混合培养，将检验IL-1β增强星形细胞系统XC活性的特定假设。利用大量的氧化应激模型，还将确定这种活性增加的功能意义。在目标2中，将进行实验以确定IL-1β调节XC系统的机制。将利用最先进的分子生物学方法来评估调控是否发生在转录和/或转录后水平。总体而言，该项目的长期目标是更好地了解IL-1β如何调节半胱氨酸-谷氨酸(系统XC)转运体。对其调控的更多了解可能使研究人员能够有针对性地治疗提高细胞内谷胱甘肽水平以减少氧化损伤。 公共卫生相关性：氧化应激是一种有害的状态，与正常衰老和各种老年人的神经疾病/障碍有关。旨在限制和修复氧化应激造成的损害的策略可能会减缓许多与年龄相关的疾病的进展。这项提议的成功完成将促进和完善我们对一个重要的新治疗靶点(系统XC-)的知识，该系统是对其他正在进行的减少与氧化应激相关的损伤的努力的补充。

DESCRIPTION (provided by applicant): Oxidative stress is a harmful condition that occurs when an imbalance between the production of reactive oxygen species (ROS) and the cellular defenses utilized to neutralize the toxic intermediates exists such that equilibrium is shifted in favor of ROS. Oxidative stress is involved in normal aging and a variety of diseases of the aged including Alzheimer's and Parkinson's disease and stroke. Recently, our laboratory has demonstrated in mixed cortical cell cultures that the cytokine interleukin-1beta (IL-1beta ) - which is upregulated in numerous neurological diseases/disorders - enhances the activity of the amino acid transporter system xc mediating an increase in cellular cyst(e)ine, a constituent of the tripeptide antioxidant molecule glutathione. Thus, the objective of this proposal is to elucidate the cellular, molecular, and biochemical mechanisms by which IL-1beta regulates system xc. In Aim 1, studies will identify the cell type or types in which the transporter is regulated. Using pure neuronal and astrocyte cultures and chimeric mixed cultures containing a combination of wild-type and system xc deficient cells, the specific hypothesis that IL-1beta enhances the activity of astrocytic system xc will be tested. Using numerous models of oxidative stress, the functional significance of this increase in activity will also be ascertained. In Aim 2, experiments will be performed to determine the mechanism by which IL-1beta regulates system xc. State of the art molecular biological approaches will be utilized to assess whether regulation occurs at the transcriptional and/or post-transcriptional level. Overall, the long-term objective of this project is to better understand how IL-1beta regulates the cystine-glutamate (system xc) transporter. A greater understanding of its regulation may enable researchers to target therapies to increase intracellular glutathione levels for the reduction of oxidative injury. PUBLIC HEALTH RELEVANCE: Oxidative stress is a harmful condition involved in both normal aging and a variety of neurological diseases/disorders of the aged. Strategies aimed at limiting and repairing the damage attributed to oxidative stress may slow the advance of many age-related diseases. Successful completion of this proposal will advance and refine our knowledge about an important new therapeutic target (system xc-) that complements other ongoing efforts to reduce injury associated with oxidative stress.