Synergy of ER stress and oxidative stress after TBI

描述(申请人提供)：内质网(ER)的有效运作对于正常的细胞功能是不可或缺的，因为内质网在维持细胞内钙稳态、蛋白质的适当折叠、翻译后修饰和将新生蛋白质运送到不同的目的地方面发挥着重要作用。内质网的任何破坏都会导致一系列复杂的信号通路的激活，这些信号通路从内质网传播到胞浆再到细胞核。这些统称为未折叠蛋白反应(UPR)，其目的是补偿损伤并恢复正常的细胞内稳态。虽然有限和短暂的UPR是有益的，但长期或严重的UPR，以及随之而来的内质网应激导致细胞死亡。此外，中枢神经系统的侮辱会导致氧化应激，而氧化应激也是神经毒性的。我们假设在创伤性脑损伤后，内质网应激和氧化应激是巧合的，相互双向增强，协同加剧继发性脑损伤。使用受控皮质撞击伤的啮齿动物模型，我们希望回答以下问题。(1)在脑损伤后，PERK介导的内质网应激途径起什么作用？(2)在脑损伤后，内质网应激与氧化应激是否相关？尤其是由PERK介导的内质网应激和由NADPH氧化酶NOX2调控的氧化应激是否相互影响？(3)敲除/抑制单独的PERK途径限速蛋白eIF2、ATF4和CHOP对脑创伤后氧化应激和神经元损伤有何影响？相反，敲除/抑制NOX2对脑创伤后内质网应激和神经元损伤有何影响？长期目标是了解内质网应激和氧化应激在脑损伤后的相互作用。

DESCRIPTION (provided by applicant): Efficient functioning of the Endoplasmic reticulum (ER) is indispensable for normal cellular functions as ER plays an important role in the maintenance of intracellular Ca2+ homeostasis, proper folding of proteins, post-translation modifications and transport of nascent proteins to different destinies. Any disruption of ER results in the activation of a complex set of signaling pathways that propagate from the ER to the cytosol to the nucleus. These are collectively known as unfolded protein response (UPR), which is aimed to compensate damage and to restore the normal cellular homeostasis. While limited and transient UPR is beneficial, prolonged or severe UPR, and the ensuing ER stress leads to cell death. Furthermore, CNS insults leads to oxidative stress which is also neurotoxic. We hypothesize that following traumatic brain injury (TBI), ER stress and oxidative stress are coincidental, potentiate each other bi-directionally and synergistically exacerbate the secondary brain damage. Using a rodent model of controlled cortical impact injury, we wish to answer the following questions. (1) What is the role of PERK-mediated ER stress pathway after TBI? (2) In the post-injury brain, are ER stress and oxidative stress connected? In particular, if ER stress mediated by PERK and oxidative stress modulated by NADPH oxidase NOX2 influence each other? (3) What is the effect of knocking-out/inhibiting individual rate-limiting proteins of PERK pathway eif2¿, ATF4 and CHOP on oxidative stress and neuronal damage after TBI? Conversely, what is the effect of knocking-out/inhibiting NOX2 on ER stress and neuronal damage after TBI? The long-term goal is to understand the mutual interplay of ER stress and oxidative stress in post-TBI brain damage.