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.

项目总结： 运动在许多方面对身体有益。骨骼肌、脑、肝、骨、脂肪组织的功能 和心脏都从各种类型的体育活动和训练中获益。患有残疾、病态的人 肥胖，或与年龄相关的疾病，通常不活跃，这会加剧他们的症状，并导致 其他类型的疾病的发展，如2型糖尿病、心血管疾病和一些 各种形式的癌症。对运动的科学探索已经变得更加分子，重点放在运动的途径上 以及调节这些益处的分子。淫羊藿素已被确认为一种运动诱导的激素， 在各种组织/器官中体现了对运动的许多适应性，包括皮下的“褐变”。 脂肪组织，骨重建，改善认知障碍和神经病理，并促进肌肉生成 骨骼肌。 在骨骼和脂肪中，淫羊藿素的作用是通过αv整合素介导的，其中αvβ5被认为是主要的受体。 然而，我对淫羊藿素与αvβ5直接相互作用的生化和生物物理特性进行了研究 提示极弱的结合，而诱导可检测到的量的淫羊藿苷的浓度 在体内和培养的细胞中，淫羊藿素介导的作用非常低，这表明淫羊藿素/受体非常高。 结合亲和力。这一悖论可以用另一个因素的存在来解释，这个因素有助于 虹膜蛋白/整合素相互作用和虹膜蛋白介导的整合素活化。我的初步数据显示， 运动诱导的循环蛋白Hsp90α与整合素αvβ5结合，并作为辅因子介导 虹膜蛋白与整合素的结合及其诱导的整合素信号转导。虹膜蛋白与许多整合素配体不同 这种虹膜蛋白很小，高度糖基化，并且缺乏识别良好的整合素结合基序，表明 配体与整合素结合的非规范方式。 生物物理和生物化学方法将用于表征由淫羊藿素(WT和WT)形成的复合体 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技术异位表达αv和β5以及肌肉和脂肪细胞 显微镜。热休克蛋白90α的作用将在小鼠身上进一步评估。综上所述，这些研究将推动 我们对虹膜蛋白介导的(或激素介导的)整合素信号的理解，这将有助于药物 和抗体开发，用于治疗肥胖、老年性疾病和神经或肌肉疾病患者 退化性疾病。 拟议的项目代表了生物化学/生物物理以及细胞生物学之间的极大平衡，在 我在博士期间接受的训练，细胞新陈代谢和动物生理学，这是主要的 斯皮格曼实验室使用的技术。布鲁斯的网络、DFCI和HMS提供的资源， 极大地促进了我的研究，并将支持我成为一名独立的科学家。