兰州大学机构库 >化学化工学院
小分子药物对细胞氧化还原系统的调控及机制研究
Alternative TitleRegulation and mechanism of small molecule drugs on cellular redox system
Miao Zhong
Subtype博士
Thesis Advisor房建国 ; 张保新
2023-05-31
Degree Grantor兰州大学
Place of Conferral兰州
Degree Name理学博士
Degree Discipline化学
Keyword氧化还原 Redox 活性氧 Reactive oxygen species 抑制剂 Inhibitors 光动力治疗 Photodynamic therapy Bmi1 Bmi1
Abstract

活性氧(ROS)作为细胞内氧化还原代谢的产物,其在生命进程中扮演着“双刃剑”的角色。一方面,适量的ROS作为信号分子通过调控蛋白质的功能和活性以及转录因子的活性进而调节基因表达、表观遗传修饰并最终控制细胞功能。另一方面,过量的ROS会导致生物大分子如DNA、脂质和蛋白质的永久损伤并最终对细胞的死亡以及潜在的疾病发展造成深远影响。针对肿瘤细胞相较于正常细胞对能够刺激细胞内ROS生成的药物更敏感这一特征,药物诱导氧化应激进而杀死肿瘤细胞是目前主要的肿瘤治疗策略之一。硫氧还蛋白(Trx)系统作为细胞内重要的氧化还原调控系统,该系统对于维持肿瘤表型和支持肿瘤生长和转移是必须的,并且与肿瘤耐药性相关。因此Trx系统是一个很有开发潜力的肿瘤治疗药物靶点。本论文主要通过以下两点开展工作:1)通过化学修饰发现有潜力的硫氧还蛋白还原酶(TrxR)选择性抑制剂;2)通过与其它调控ROS的治疗手段联用探究Trx系统在其中的作用机制及对治疗效果的影响。主要内容如下:

第一章 绪论部分概述了细胞内氧化还原代谢及其在肿瘤治疗和发展中的作用。简述Trx/TrxR系统并归纳总结了其对下游相关氧化还原蛋白的调控机制以及部分经典的TrxR抑制剂。简单介绍了光动力治疗(PDT)并对铱(Ш)光敏剂发展进行综述。

第二章 以具有丰富生物活性胡椒碱为母体化合物,设计合成了一系列胡椒碱衍生物并评估了其生物活性。经过筛选实验,选出了相较母体化合物细胞毒性提高约4倍的类似物P-B5。进一步研究其生物活性,发现P-B5可以选择性抑制TrxR活性,导致细胞内出现氧化应激并最终诱导肿瘤细胞凋亡。P-B5的合成及其生物活性的研究为胡椒碱类似物作为TrxR抑制剂的进一步改性和应用研究提供了指导。

第三章 设计和合成了一系列含磺酰胺骨架的潜在的TrxR抑制剂。评价了它们对不同类型肿瘤细胞的细胞毒性及体外对TrxR的抑制作用。所筛选的A3化合物对HeLa细胞具有较大的细胞毒性,并对TrxR的抑制具有特异性。进一步机制研究显示,其通过靶向Sec选择性抑制TrxR,并诱导细胞内出现氧化应激最终导致肿瘤细胞凋亡。此外,化合物A3在对肿瘤细胞迁移和侵袭方面也表现出明显的抑制,同时,也能够抑制小鼠体内肿瘤生长。

第四章 评估了一批课题组前期合成的铱(Ш)配合物作为光敏剂在光动力治疗中的活性。通过最初的细胞毒性筛选,选择光毒性指数最高的复合物PC9,之后进一步研究了PC9在细胞中的生物活性。实验发现,当PC9暴露于光下时,HeLa细胞会产生大量的活性氧。PC9作为光敏剂能有效靶向线粒体,破坏细胞内氧化还原调节机制,最终导致细胞凋亡。铱(Ш)复合物作为光敏剂可以强烈靶向细胞器,并通过损害细胞内氧化还原调节机制使PDT效应更敏感,这种光敏剂研究思路是本文第一次报道的,为未来设计和开发有效的新型光敏剂提供了新的视角。

第五章 研究发现了一个新的受到Trx调控的下游蛋白Bmi1。Bmi1的巯基易被氧化,氧化处理后蛋白分子量发生变化,而这一变化能够被Trx系统恢复。此外,联合使用Trx系统和Bmi1的抑制剂能够协同抑制细胞增殖,这提出了一种新的抗肿瘤治疗策略。

第六章 对全文工作进行总结并对课题后续发展提出展望,主要围绕后续光敏剂的开发及Bmi1氧化还原调控机制作出展望。

Other Abstract

Reactive oxygen species (ROS), as the products of intracellular redox metabolism, play a “Double-edged sword” role in the process of life. On the one hand, ROS, as a signal molecule, regulates gene expression, Epigenetics and ultimately cell function by regulating the function and activity of proteins and transcription factors. On the other hand, excessive ROS can cause permanent damage to biological macromolecules such as DNA, lipids and proteins, and ultimately have a profound impact on cell death and the development of potential diseases. Targeting the fact that tumor cells are more sensitive than normal cells to drugs that stimulate intracellular ROS production, drugs that induce oxidative stress and then kill tumor cells are currently one of the major tumor therapeutic strategies. The thioredoxin (Trx) system serves as an important intracellular redox regulatory system that is essential for maintaining tumor phenotype and supporting tumor growth and metastasis and is associated with tumor drug resistance. Therefore, Trx system is a potential target for cancer therapy. This thesis focuses on the discovery of potential Thioredoxin reductase (TrxR) selective inhibitors by chemical modification and the exploration of the mechanism of Trx system and its influence on the therapeutic efficacy by combining it with other ROS-regulating therapies. The main content is as follows:

In chapter 1, the introduction summarizes the intracellular redox metabolism and its role in the treatment and development of cancer. The Trx/TrxR system and its regulatory mechanism on downstream redox proteins and some classical TrxR inhibitors were summarized. This paper briefly introduces photodynamic therapy and reviews the development of Iridium (Ш) photosensitizers.

In chapter 2, a series of Piperine derivatives were designed and synthesized, and their biological activities were evaluated. Through the screening experiment, the analogue P-B5 was selected, whose cytotoxicity was about 4 times higher than that of the parent compound. Further study of its biological activity showed that P-B5 could selectively inhibit TrxR activity, leading to intracellular oxidative stress and ultimately induced apoptosis of tumor cells. The biological activity of P-B5 provide guidance for further modification and application of Piperine analogues as TrxR inhibitors.

In chapter 3, a series of potential TrxR inhibitors containing sulfonamide skeleton were designed and synthesized. Their cytotoxicity to different types of tumor cells and their inhibitory effects on TrxR in vitro were evaluated. The selected compounds A3 showed high cytotoxicity to HeLa cells and specific inhibition to TrxR. Further mechanistic studies have shown that it selectively inhibits TrxR by targeting Sec and induces intracellular oxidative stress that ultimately leads to tumor cell apoptosis. In addition, compound A3 showed obvious activity in the migration and invasion of tumor cells, and also inhibited tumor growth in mice.

In chapter 4, the activity of Iridium (Ш) complexes as photosensitizers in photodynamic therapy was evaluated. After the initial cytotoxicity screening, the complex PC9 with the highest phototoxicity index was selected, and the biological activity of PC9 in cells was further investigated. When PC9 was exposed to light, the HeLa cells produced large amounts of ROS. PC9 can effectively target mitochondria as photosensitizer, destroy the regulation mechanism of redox in cells, and finally lead to apoptosis. Iridium (Ш) complexes as photosensitizers can strongly target organelles and make PDT effects more sensitive by impairing intracellular redox regulatory mechanisms, a line of thought for photosensitizer research first reported in this paper, it provides a new perspective for the design and development of effective new photosensitizers in the future.

In chapter 5, a novel Trx-regulated downstream protein, Bmi1, was discovered. The sulfhydryl group of Bmi1 is easy to be oxidized, and the molecular weight of BMI1 protein changes after oxidative treatment, which can be recovered by Trx system. In addition, the synergistic inhibition of cell proliferation with inhibitors of the Trx system and Bmi1 suggests a novel anti-tumor therapeutic strategy.

In the sixth chapter, we summarize the work of this thesis and make a prospect for the future development of this subject, mainly focusing on the development of photosensitizers and the redox regulation mechanism of Bmi1.

Subject Area化学生物学
MOST Discipline Catalogue理学 - 化学
URL查看原文
Language中文
Other Code262010_120190903890
Document Type学位论文
Identifierhttps://ir.lzu.edu.cn/handle/262010/535845
Collection化学化工学院
Affiliation
兰州大学化学化工学院
Recommended Citation
GB/T 7714
Miao Zhong. 小分子药物对细胞氧化还原系统的调控及机制研究[D]. 兰州. 兰州大学,2023.
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