Critical role of NRF2 in globin gene regulation in sickle cell disease mouse models

项目摘要/摘要 患有镰状细胞病(SCD)的人由于慢性红血球而患有严重贫血。 溶血和氧化应激增加导致内皮细胞功能障碍和 血管病变。诱导γ-珠蛋白基因有效表达和胎儿的策略 血红蛋白(HBF)的合成将缓解SCD的临床症状。此外，SCD表型 严重程度可以通过减少氧化应激来改善。我们之前已经证明了 转录因子NRF2(核因子(红系2)样2)被二甲基激活 富马酸是诱导红系祖细胞发生HBF的机制之一。我们还演示了一个 利用一种新型的NRF2基因敲除SCD，NRF2在改善SCD严重程度中的重要作用 本实验室建立的小鼠模型。为了扩展这些发现，我们将确定 核转录因子2介导的γ-珠蛋白基因调控和红细胞生成的分子机制 DNA和组蛋白在发育过程中的表观遗传修饰。我们将进一步评估其能力 NRF2激活剂在减轻SCD小鼠模型疾病严重程度中的作用。我们的具体目标是 探讨NRF2介导的珠蛋白基因调控在SCD小鼠中的表观遗传学机制 模拟和开发新型HBF诱导剂。在分目标A中，我们将确定 NRF2基因敲除对红系分化和珠蛋白基因调控的影响。我们将研究 NRF2缺失对红细胞生成、代谢和基因表达的影响NRF2的影响 脾DNA和组蛋白表观遗传修饰中HBb染色质结构的丢失 将对造血组织进行调查。在子目标B中，我们将评估FDA批准的NRF2 激活药物作为新型HBF诱导剂。FDA批准的药物，包括富马酸二甲酯 将对所有NRF2激活剂(Tecfidera)、辛伐他汀(Zocor)和MLN9708(Ixazomib)进行测试。 NRF2激活剂对红细胞生成、HBb基因座染色质结构及缓解作用的影响 临床前SCD小鼠模型的疾病严重程度将被确定。所获得的知识将 通过表观遗传DNA和组蛋白揭示NRF2在珠蛋白基因调控中的关键作用 修改并验证用于治疗SCD的新型NRF2激活剂的设计。

Project Summary/Abstract Individuals with sickle cell disease (SCD) have severe anemia due to chronic red blood cell hemolysis and increased oxidative stress producing endothelial cell dysfunction and vasculopathy. Strategies to induce efficacious levels of γ-globin gene expression and fetal hemoglobin (HbF) synthesis will alleviate SCD clinical symptoms. In addition, SCD phenotypic severity is ameliorated by reducing oxidative stress. We previously demonstrated that transcription factor NRF2 (nuclear factor (erythroid-derived 2)-like 2) is activated by dimethyl fumarate as a mechanisms of HbF induction in erythroid progenitors. We also demonstrated an essential role of NRF2 in ameliorating the severity of SCD using a novel NRF2 knockout SCD mouse model established in our laboratory. To expand on these findings, we will determine the molecular mechanism of NRF2-mediated γ-globin gene regulation and erythropoiesis through DNA and histone epigenetic modifications during development. We will further assess the ability of NRF2 activators in alleviating disease severity in SCD mouse models. Our Specific Aim is to determine epigenetic mechanisms of NRF2-mediated globin gene regulation in the SCD mouse model and develop novel HbF inducing agents. In Sub-aim A, we will determine the effects of NRF2 knockout on erythroid differentiation and globin gene regulation. We will examine the effects of NRF2 loss on erythropoiesis, metabolism and gene expression. The effects of NRF2 loss on HBB chromatin structure for DNA and histone epigenetic modifications in splenic hematopoietic tissue will be investigated. In Sub aim B, We will evaluate the FDA-approved NRF2 activating drugs as novel HbF inducers. FDA-approved drugs, including dimethyl fumarate (Tecfidera), Simvastatin (Zocor), and MLN9708 (Ixazomib), all NRF2 activators, will be tested. The effect of NRF2 activators on erythropoiesis, HBB locus chromatin structure and in alleviating disease severity in preclinical SCD mouse model will be determined. The knowledge gained will reveal the critical role of NRF2 in globin gene regulation through epigenetic DNA and histone modifications and validate the design of novel NRF2 activators for the treatment of SCD.