Testing brain penetrant iron chelators and investigating putative clearance pathway in ICH

脑出血(ICH)是一种由脑出血引起的严重疾病。应该指出的是 在2019年2月举行的上一次AHA/ASA国际中风会议上，从一个阶段提出了研究结果 III试验显示去铁胺(DFO)对脑出血无效。一种可能的解释是DFO并非如此 越过血脑屏障，它有严重的毒性问题。因此，现在的主要重点是确定疗效和 通过检测独特的脑渗透性铁为治疗脑出血的新方法提供安全有效的治疗窗口 螯合剂。为了实现这一目标，并基于文献和我们的初步数据，我们将测试有效和 选择性铁络合剂，如HBED，其疗效将与其他铁络合剂进行比较，如 DADMDFT模拟和DFO。 颅内出血后，红细胞溶解并释放大量的血红蛋白(Hb)。这些必须是 被积极地吞噬，之后血红素(不能再循环)被降解以产生铁 在细胞内。在正常生理条件下，应保持铁的动态平衡；然而，当 有太多的(血红素)底物，也有太多的铁，这一过程称为铁代谢失调。我们的 总体假设是，亲脂性脑渗透铁络合剂对脑出血有效。值得注意的是，HBED 与DFO相比，DFO的安全性也要好得多，后者是在一次彻底的第一阶段安全试验后注意到的。 我们观察到，在创伤性脑损伤模型后，HBED是最有效的。此外，我们还发现DADMDFT 在无基质的Hb注射模型中，通过改善功能和解剖结果提供好处。 除了结合铁，HBED还结合亚铁(有毒)铁，并在细胞中将其转化为铁(无毒)铁 线粒体，防止促氧化剂和促炎剂的级联。 目的1比较HBED与DADMDFT和DFO在改善神经行为和功能障碍方面的疗效。 脑出血后的解剖学结果。我们将确定并比较最佳剂量反应和治疗 成年雄性小鼠HBED、DADMDFT和DFO的窗口，雌性小鼠并行。目标2、3和4旨在 研究已知的吞噬细胞受体CD36和CD163分别对红细胞和Hb的重要性， 采用自体血脑出血临床前模型。我们将使用单次击倒和双次击倒(与匹配 C57BL/6产仔)，我们已经产生了。目标是机械地理解各自的 这些吞噬细胞受体的作用，因为它们应该参与红细胞和血红蛋白的清除 并测试最佳铁络合剂的额外好处，帮助限制氧化/炎症应激 瀑布。毒性将被监测，以及脑和血清铁水平随着时间的推移，治疗后 铁络合剂。 这个项目是及时的，我们相信我们已经组建了一个独特的团队，拥有工具、动物、模型和 严格执行这些实验所需的专业知识。我们有信心能够完成 Proposed旨在告知我们的中风合作伙伴，使他们能够设计一项严格的临床试验。

Intracerebral hemorrhage (ICH) is a serious medical condition caused by bleeding in the brain. It should be noted that at the last AHA/ASA International Stroke Conference in Feb. 2019, findings were presented from a Phase III trial showing that deferoxamine (DFO) was futile against ICH. One potential explanation is that DFO does not cross the BBB, and it has significant toxicity issues. Thus, the main focus now is to determine the efficacy and therapeutic window of a novel, safe, and effective therapy against ICH by testing unique brain penetrant iron chelators. To achieve this goal, and based on the literature and our preliminary data, we will test potent and selective iron chelators such as HBED, and their efficacy will be compared to other iron chelators such as the DADMDFT analog and DFO. After intracranial bleeding, red blood cells lyse and release large amounts of hemoglobin (Hb). These have to be actively phagocytosed, after which the heme (which cannot be recycled) gets degraded to generate iron intracellularly. Under normal physiological conditions, iron homeostasis should be maintained; however, when there are too many (heme) substrates, there is also too much iron, a process called iron dyshomeostasis. Our overall hypothesis is that a lipophilic brain penetrant iron chelator would be effective against ICH. Notably, HBED also has a much better safety profile compared to DFO, which was noted after a thorough Phase I safety trial. We observed that HBED was most potent after a traumatic brain injury model. Also, we found that DADMDFT provides benefits by improving functional and anatomical outcomes in the stroma-free Hb injection model. Besides binding iron, HBED binds ferrous (toxic) iron and converts it into ferric (nontoxic) iron in cells and mitochondria, preventing prooxidant and proinflammatory cascades. Aim 1 is to investigate the efficacy of HBED over DADMDFT and DFO in improving neurobehavioral and anatomical outcomes after ICH. We will determine and compare the optimal dose-response and therapeutic window of HBED, DADMDFT, and DFO in adult male mice and in parallel in females. Aims 2, 3, and 4 are to investigate the importance of the known phagocytic receptors CD36 and CD163 for RBCs and Hb, respectively, using the autologous blood ICH preclinical model. We will use the single and double knockouts (versus matched C57BL/6 littermates) that we have already generated. The goal is to understand mechanistically the respective role of these phagocytic receptors because they should participate in the clearance of RBCs and hemoglobin and test the added benefits of the optimal iron chelator, helping to limit the oxidative/inflammatory stress cascades. Toxicity will be monitored, along with brain and serum iron levels over time, after treatment with the iron chelator. This project is timely, and we believe we have assembled a unique team with the tools, animals, models, and expertise necessary to rigorously perform these experiments. We are confident that we can accomplish the proposed aims to inform our stroke partners, allowing them to design a rigorous clinical trial.