Regulation of System xc- by Interleukin-1 beta

描述（由申请人提供）：氧化应激是一种有害的情况，当活性氧（ROS）的产生与用于中和有毒中间体的细胞防御之间存在不平衡，从而使平衡向有利于ROS的方向转移时，就会发生氧化应激。氧化应激与正常衰老和多种老年人疾病有关，包括阿尔茨海默病、帕金森病和中风。最近，我们的实验室在混合皮质细胞培养中证明，在许多神经系统疾病/紊乱中上调的细胞因子白介素-1 β (il -1 β)可以增强氨基酸转运系统的活性，从而介导细胞囊氨酸(e)的增加，而细胞囊氨酸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 -1 β调节系统xc的细胞、分子和生化机制。在目标1中，研究将确定转运蛋白受到调节的细胞类型。使用纯神经元和星形胶质细胞培养物以及包含野生型和系统xc缺陷细胞组合的嵌合混合培养物，il -1 β增强星形胶质细胞系统xc活性的特定假设将得到验证。使用许多氧化应激模型，这种活性增加的功能意义也将被确定。在目标2中，将进行实验以确定il -1 β调节系统xc的机制。最先进的分子生物学方法将被用来评估调控是否发生在转录和/或转录后水平。总的来说，该项目的长期目标是更好地了解il -1 β如何调节胱氨酸-谷氨酸（系统xc）转运蛋白。对其调控的更深入了解可能使研究人员能够靶向治疗，以增加细胞内谷胱甘肽水平，以减少氧化损伤。

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.