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Cytoprotection and the mechanism of action of a natural product Khellin against ER stress

天然产物 Khellin 对抗 ER 应激的细胞保护和作用机制

基本信息

批准号：
9974514
负责人：
Weidong Wang
金额：
$ 36.25万
依托单位：
UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-01 至 2022-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9974514
关键词：
ATF6 gene Affect Ammi visnaga Animal Model Animals Asthma Atherosclerosis Attenuated B-Lymphocytes Beta Cell Biochemical Biological Assay Cause of Death Cell Death Cell model Cells Cellular Assay Cessation of life Chemicals Chronic Coronary heart disease Cytoprotection Cytoprotective Agent Degenerative Disorder Development Diabetes Mellitus Diabetic mouse Dimerization Disease Drug Targeting Eating Endoplasmic Reticulum Event Exhibits Foundations Functional disorder Grant Homeostasis Hyperglycemia Insulin Islet Cell Islets of Langerhans Transplantation Lead Mediating Membrane Messenger RNA MicroRNAs Modeling Molecular Molecular Mechanisms of Action Mus Natural Products Neurodegenerative Disorders Obesity Organ Pancreas Pathogenesis Pathway interactions Patients Peripheral Pharmaceutical Preparations Pharmacotherapy Phosphorylation Phosphotransferases Pilot Projects Plant Extracts Play Process Proteins Public Health RNA Decay RNA Degradation RNA Splicing Research Research Design Ribonucleases Role Severities Streptozocin Structure of beta Cell of islet Technology Testing Therapeutic Time Transplantation Weight Gain Work analog base cell type clinical development db/db mouse diabetic dimer endoplasmic reticulum stress high throughput screening human disease improved in vivo insight insulin secretion insulin sensitivity misfolded protein novel overexpression response small molecule therapeutic target

项目摘要

Endoplasmic reticulum (ER) stress plays an important role in the pathogenesis of a growing list of human diseases, including diabetes, obesity, atherosclerosis, and neurodegenerative diseases. Chronic ER stress leads to cell dysfunction and death through the hyperactivation of the unfolded protein response (UPR), and hence has been proposed as a therapeutic target for the treatment of these diseases. However, no drugs targeting ER stress/UPR-induced cell dysfunction and death have yet been identified. Using high throughput screen technology, we have identified a natural product, a furanochromone derivative, as a molecule of cytoprotection against ER stress. Our preliminary studies revealed that (a) in cell-based assays, the furanochromone derivative protects β cells against ER stress-, glucotoxicity-, and lipotoxicity-induced dysfunction and death, (b) the furanochromone ameliorates hyperglycemia and protects the function and survival of β cells in streptozotocin-induced diabetic animals, and (c) the furanochromone also protects other cell types against ER stress. These studies revealed for the first time that this natural product exhibits cytoprotection against ER stress. Our pilot studies further indicate that the furanochromone derivative selectively inhibits the ER stress-induced activation of one of three unfolded protein response pathways, IRE1α pathway, with no effect on the other two pathways: PERK and ATF6. These findings led to our central hypothesis that this compound inhibits ER stress-induced IRE1α hyperactivation to confer cytoprotection. In this grant, we propose three aims to test this hypothesis. In aim 1, we will determine the mechanism of action of this compound on IRE1α inhibition. We will use biochemical assays to determine the effects of the furanochromone derivative on IRE1a kinase and RNase activities and its phosphorylation and dimeric/oligomeric statuses. In aim 2, we will determine whether the compound confers cytoprotective activity by inhibiting IRE1α. These studies will establish its inhibition on IRE1α activation as the molecular mechanism of the compound’s cytoprotection. Finally, we will determine therapeutic potential of the compound in well-established ER stress-related animal models: two diabetes models of progressive β cell loss (Akita mice and db/db mice). Together, this work will reveal not only a novel cytoprotective activity of the natural product against ER stress but also elucidate its inhibition of IRE1α activity as the molecular mechanism of action underlying its cytoprotection, thus establishing the foundation for the clinical development of the furanochromone derivatives as novel cytoprotective drugs for ER stress-related diseases.

内质网（ER）应激在越来越多的人类疾病的发病机制中起着重要作用，包括糖尿病、肥胖、动脉粥样硬化和神经退行性疾病。慢性内质网应激通过过度激活未折叠蛋白反应（UPR）导致细胞功能障碍和死亡，因此已被提议作为治疗这些疾病的治疗靶点。然而，尚未确定靶向ER应激/UPR诱导的细胞功能障碍和死亡的药物。利用高通量筛选技术，我们已经确定了一种天然产物，呋喃色酮衍生物，作为对ER应激的细胞保护分子。我们的初步研究表明，（a）在基于细胞的测定中，呋喃色酮衍生物保护β细胞免受ER应激、葡萄糖毒性和脂毒性诱导的功能障碍和死亡，（B）呋喃色酮改善高血糖症并保护链脲霉素诱导的糖尿病动物中β细胞的功能和存活，以及（c）呋喃色酮还保护其他细胞类型免受ER应激。这些研究首次揭示了这种天然产物对ER应激具有细胞保护作用。我们的初步研究进一步表明，呋喃色酮衍生物选择性地抑制ER应激诱导的三条未折叠蛋白反应途径之一的激活，IRE 1 α途径，而对其他两条途径没有影响：PERK和ATF 6。这些发现导致了我们的中心假设，即该化合物抑制ER应激诱导的IRE 1 α超活化，从而提供细胞保护。在本研究中，我们提出了三个目标来验证这一假设。在目标1中，我们将确定该化合物对IRE 1 α抑制的作用机制。我们将使用生化测定来确定呋喃色酮衍生物对IRE 1a激酶和RNA酶活性及其磷酸化和二聚体/寡聚体状态的影响。在目标2中，我们将确定该化合物是否通过抑制IRE 1 α赋予细胞保护活性。这些研究将确定其对IRE 1 α活化的抑制作为化合物细胞保护的分子机制。最后，我们将确定该化合物在成熟的ER应激相关动物模型中的治疗潜力：两种进行性β细胞丢失的糖尿病模型（秋田小鼠和db/db小鼠）。本研究不仅揭示了天然产物对ER应激的新型细胞保护活性，而且阐明了其抑制IRE 1 α活性的分子机制，从而为呋喃色酮衍生物作为ER应激相关疾病的新型细胞保护药物的临床开发奠定了基础。