Regulation of IL-1β bioactivity by Cysteine S-glutathionylation

项目摘要 IL-1β是宿主防御入侵病原体的主要参与者。相反，过量的IL-1β产生 和/或激活可能对系统有害，导致不希望的和过度的组织炎症。 因此，需要很好地控制IL-1β的生物活性。IL-1β调节的机制传统上 专注于模式识别受体诱导的基因转录和炎性小体介导的切割， pro-IL-1β。完整的IL-1β细胞因子调控库在很大程度上仍然是未知的。的目的 提出的研究是鉴定和表征调节成熟IL-10生物活性的生物化学事件。 1β从细胞中释放后。我们最近发现，高度保守的半胱氨酸S-谷胱甘肽化 IL-1β中Cys-188残基通过抑制不可逆活性氧的产生对IL-1β生物活性的影响 物种（ROS）引起的氧化和失活。蛋白质谷胱甘肽化是动态可逆的。我们 进一步证明了存在谷氧还蛋白1（Grx 1），一种催化脱谷胱甘肽化的酶， 在血清和BM的细胞外空间中具有活性，并在生理上调节IL-1β谷胱甘肽化。 总之，这些结果使我们假设ROS诱导的半胱氨酸S-谷胱甘肽化及其 Grx 1的调节是在病理生理条件下控制IL-1β活性的关键调节机制。 条件在目前的研究中，我们将在一个临床相关模型中检验这一假设，在该模型中，IL-1β活性是 这对于辐射后造血系统的有效恢复是必要的和足够的。一是 确定半胱氨酸S-谷胱甘肽化在调节内源性产生的IL-1β的生物活性中的作用 在照射后骨髓（BM）恢复期间（Aim I）。此外，我们还将阐明Grx 1的功能， 在辐射小鼠的BM恢复中调节内源性产生的IL-1β的S-谷胱甘肽化。我们还将 确定BM中产生Grx 1的细胞类型（Aim II）。最后，我们将尝试加速BM恢复， 通过靶向IL-1β S-谷胱甘肽化进行照射。我们先来看看谷胱甘肽静脉注射 (GSH IV）治疗可提高IL-1β的生物活性，加速造血系统的恢复， 辐射小鼠此外，我们还将研究IL-1β 188 C/S，一种不能被免疫抑制的IL-1β突变体， 氧化和失活，在辐射小鼠中引发BM保护作用方面比WT IL-10更有效。 1β（目标III）。总之，在这三个具体目标中提出的实验将使人们更好地了解 ROS诱导的半胱氨酸S-谷胱甘肽化在体内控制IL-1β活性中的作用 设置.对于翻译研究范式，本研究的结果将有助于我们识别新的 治疗靶点（如ROS、Grx 1和相关通路），用于加速接受 放疗

Project Summary IL-1β is a major player in host defense against invading pathogens. Conversely, excessive IL-1β production and/or activation can be detrimental to the system, resulting in unwanted and exaggerated tissue inflammation. Hence, the bioactivity of IL-1β needs to be well controlled. Mechanisms of IL-1β regulation have traditionally focused on pattern recognition receptor-induced gene transcription and inflammasome-mediated cleavage of pro-IL-1β. The complete IL-1β cytokine regulatory repertoire is still largely unknown. The objective of the proposed research is to identify and characterize biochemical events that modulate the bioactivity of mature IL- 1β after its release from the cells. We recently found that cysteine S-glutathionylation of the highly conserved Cys-188 residue in IL-1β positively regulates IL-1β bioactivity by preventing its irreversible reactive oxygen species (ROS)-elicited oxidation and deactivation. Protein glutathionylation is dynamic and reversible. We further demonstrated that Glutaredoxin 1 (Grx1), an enzyme that catalyzes deglutathionylation, is present and active in the extracellular space in serum and BM, and physiologically regulates IL-1β glutathionylation. Together, these results lead us to hypothesize that ROS-induced cysteine S-glutathionylation and its modulation by Grx1 are key regulatory mechanisms controlling IL-1β activity under pathophysiological conditions. In current study, we will test this hypothesis in a clinically relevant model in which IL-1β activity is both essential and sufficient for efficient recovery of the hematopoietic system after irradiation. First, we will determine the role of cysteine S-glutathionylation in regulating the bioactivity of endogenously produced IL-1β during bone marrow (BM) recovery after irradiation (Aim I). In addition, we will elucidate the function of Grx1 in regulating S-glutathionylation of endogenously produced IL-1β in BM recovery in irradiated mice. We will also identify the cell types that produce Grx1 in the BM (Aim II). Finally, we will try to accelerate BM recovery after irradiation by targeting IL-1β S-glutathionylation. We will first examine whether glutathione intravenous injection (GSH IV) therapy can elevate IL-1β bioactivity and accelerate the recovery of the hematopoietic system in irradiated mice. In addition, we will investigate whether IL-1β 188C/S, a mutant form of IL-1β that can not be oxidized and deactivated, is more potent in eliciting BM protective effect in irradiated mice compared to WT IL- 1β (Aim III). Together, experiments proposed in these three specific aims will provide a better understanding of the role of ROS-induced cysteine S-glutathionylation in controlling IL-1β activity in vivo in clinically relevant settings. Toward the translational research paradigm, results from this study will assist us to identify novel therapeutic targets (e.g. ROS, Grx1, and related pathways) for accelerating BM recovery in patients receiving radiotherapy.