Elucidating novel molecular mechanisms of irisin-mediated effects via integrin

通过整合素阐明鸢尾素介导作用的新分子机制

• 批准号: 10617263
• 负责人: Mu A
• 金额: $ 7.18万
• 依托单位: DANA-FARBER CANCER INST
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10617263
• 关键词: Adipocytes; Adipose tissue; Affect; Affinity; Affinity Chromatography; Amino Acids; Animals; Antibodies; Binding; Biochemical; Biochemistry; Biological; Biophysics; Blood; Bone remodeling; Brain; Bypass; Cardiovascular Diseases; Cardiovascular system; Cell Culture Techniques; Cell surface; Cells; Cellular Metabolic Process; Cellular biology; Cognitive deficits; Complex; Cultured Cells; Data; Degenerative Disorder; Development; Disease; Disease Progression; Equilibrium; Exercise; Exhibits; Fatty acid glycerol esters; Fibronectins; Fluorescence Microscopy; Functional disorder; Half-Life; Heart; Heat-Shock Response; Hormones; Human; Individual; Integrin Binding; Integrin alphaV; Integrins; Life Style; Ligand Binding; Ligands; Liver; Malignant Neoplasms; Mammalian Cell; Maps; Measures; Mediating; Membrane Proteins; Mental disorders; Metabolic Diseases; Metabolism; Molecular; Morbid Obesity; Mus; Muscle; Muscle Cells; Muscle Fibers; Muslim religion; N-terminal; Nature; Non-Insulin-Dependent Diabetes Mellitus; Nuclear; Organ; PPAR gamma; Pathogenesis; Pathway interactions; Pattern; Persons; Pharmaceutical Preparations; Physical activity; Physiology; Plasma; Proteins; Publishing; RGD (sequence); Recombinant Proteins; Recombinants; Research; Resources; Role; Scientist; Signal Transduction; Site; Skeletal Muscle; Structure; Symptoms; Technology; Testing; Therapeutic; Tissues; Training; Transcription Coactivator; Work; age related; biophysical properties; bone; cofactor; disability; endurance exercise; glycosylation; improved; in vivo; molecular modeling; mutant; myogenesis; neuropathology; novel; obese patients; physical inactivity; polypeptide; prevent; protein purification; receptor; receptor binding; sedentary; sedentary lifestyle; subcutaneous

PROJECT SUMMARY: Exercise benefits the body in many ways. The functions of skeletal muscle, brain, liver, bone, adipose tissue and heart all gain from various types of physical activity and training. People suffering from disabilities, morbid obesity, or age-related diseases, are usually physically inactive, which exacerbates their symptoms and leads to development of other types of diseases, such as type 2 diabetes mellitus, cardiovascular diseases, and some forms of cancers. Scientific explorations of exercise have become more molecular, focusing on the pathways and molecules that mediate these benefits. Irisin has been identified as an exercise-induced hormone that embodies many adaptations to exercise in a variety of tissues/organs, including “browning” of subcutaneous adipose tissue, bone remodeling, improving cognitive deficits and neuropathology, and promoting myogenesis of skeletal muscles. In bone and fat, the effects of irisin are mediated via αv integrins, with αvβ5 identified as the major receptor. However, my biochemical and biophysical characterization of direct interaction between irisin and αvβ5 suggested extremely weak binding, while the concentrations of irisin that induce detectable amount of irisin-mediated effects in the body and in the cultured cells are really low, indicating a very high irisin/receptor binding affinity. This paradox could be explained by the existence of an additional factor that facilitates irisin/integrin interaction and irisin-mediated integrin activation. My preliminary data suggested that an exercise-induced circulating protein Hsp90α binds to integrin αvβ5, and functions as a cofactor to mediate the binding of irisin to integrin and irisin-induced integrin signaling. Irisin is different from many integrin ligands in that irisin is small, heavily glycosylated, and lacks the well-identified integrin binding motif, indicating a non-canonical ways of ligand binding to integrins. Biophysical and biochemical approaches will be used to characterize the complexes formed by irisin (WT and glycosylation mutants), αvβ5 and Hsp90α. The molecular model will be firstly tested in HEK293T cells ectopically expressing αv and β5, and muscle and fat cells, using molecular approaches and fluorescence microscopy. The effects of Hsp90α will be further evaluated in mice. Taken together, these studies will advance our understanding of irisin-mediated (or hormone-mediated, in general) integrin signaling, which will assist drug and antibody development to treat patients with obesity, aged-related diseases and neuro- or muscular degenerative disorders. The proposed project represents a great balance between biochemistry/biophysics as well as cell biology, in which I was trained during my Ph.D, and cell metabolism and animal physiology, which are the primary technologies employed by the Spiegelman lab. The resources provided by Bruce’s networks, DFCI and HMS, tremendously facilitated my research, and will support me to become an independent scientist.

项目摘要： 运动在许多方面使身体受益。骨骼肌，大脑，肝脏，骨，脂肪组织的功能 心脏都从各种类型的体育锻炼和训练中获利。患有残疾的人，病态 肥胖或与年龄有关的疾病通常是身体不活跃的，这会加剧其症状并导致 开发其他类型的疾病，例如2型糖尿病，心血管疾病和一些疾病 癌症的形式。运动的科学探索已经变得更加分子，重点是 和介导这些好处的分子。虹膜蛋白已被确定为一种运动引起的激素 体现了许多适应在各种组织/器官中运动的改编，包括皮下的“褐变” 脂肪组织，骨骼重塑，改善认知缺陷和神经病理学以及促进肌发生 骨骼肌。 在骨骼和脂肪中，虹膜蛋白的作用是通过αV整合素介导的，αVβ5被鉴定为主要接收器。 但是，我对虹膜蛋白和αVβ5之间直接相互作用的生化和生物物理表征 建议的结合极弱，而影响可检测量的虹膜蛋白的浓度 虹膜蛋白介导的体内和培养细胞中的作用确实很低，表明非常高的虹膜蛋白/受体 结合亲和力。这种悖论可以通过促进的附加因素来解释 虹膜蛋白/整合素相互作用和虹膜蛋白介导的整联蛋白激活。我的初步数据表明 运动诱导的循环蛋白HSP90α与整联蛋白αVβ5结合，并用作辅助因子，以介导 虹膜蛋白与整联蛋白和虹膜蛋白诱导的整联蛋白信号的结合。虹膜蛋白与许多整合素配体不同 虹膜蛋白很小，大量的糖基化，缺乏识别良好的整合素结合基序，表明是 配体与整联蛋白结合的非经典方式。 生物物理和生化方法将用于表征虹膜蛋白（WT和 糖基化突变体），αVβ5和HSP90α。分子模型将首先在HEK293T细胞中进行测试 使用分子方法和荧光以生态表达αV和β5，以及肌肉和脂肪细胞 显微镜。 Hsp90α的作用将在小鼠中进一步评估。两者一起，这些研究将进步 我们对虹膜蛋白介导的（或马酮介导的，一般而言）整联蛋白信号传导的理解，这将有助于药物 和抗体发育以治疗肥胖症患者，老年相关疾病和肌肉或肌肉 退化性疾病。 拟议的项目代表了生物化学/生物物理学和细胞生物学之间的巨大平衡， 我在博士学位上接受了训练，以及细胞代谢和动物生理学，这是主要的 Spiegelman实验室工作的技术。布鲁斯网络，DFCI和HMS提供的资源， 极大地支持我的研究，并将支持我成为一名独立科学家。