Molecular Profiling of Pancreatic Pathophysiology by Imaging Mass Spectrometry

 描述(申请人提供)：虽然分泌激素的胰岛细胞(如细胞和ç细胞)已被确定在血糖稳态中发挥关键作用，但我们对正常胰腺器官发生和导致代谢状态改变(如2型糖尿病(T2D))的重要过程的了解仍然有限。人类胰岛的利用率低，缺乏全面分析胰岛细胞及其组织环境的实验方法，限制了我们绘制细胞信号通路和代谢图的能力。尽管在治疗和治愈方面取得了实质性的进展，但对于导致ç细胞功能障碍的具体信号和损伤途径仍有许多未知之处。需要对胰岛发育和糖尿病病理生理学有更基本的了解，以帮助指导诊断、预后、治疗和治疗，并可能从分子水平开始。通过这种方式，新的生化理解可以转化为对胰腺发育和疾病进展的洞察，最终导致识别新的潜在生物标志物和治疗靶点。本文提出的基于发现的研究将通过将一种新的分子成像技术--基质辅助激光解吸/电离成像质谱仪(MALDI IMS)与现有的有效方法相结合，从分子水平上深入了解胰岛的结构、功能和发育。这项技术非常适合测量细胞组织中存在的复杂的分子信息(如脂质和蛋白质)阵列，并提供了一种非靶向测量方法，这是发现对胰腺功能重要的新分子的理想方法。我们的目标是利用这种基于组织的原位IMS技术，为不同类型的胰腺内分泌细胞开发更完整的分子图谱，使我们能够深入了解参与胰腺发育和疾病进展的细胞信号通路。这些IMS技术将被用来专门定义正常小鼠胰岛的脂质和蛋白质分子特征，并将这些图谱与在肥胖和胰岛素抵抗存在时观察到的功能变化相关联。这将使我们能够在研究良好的ob/ob小鼠模型中建立那些对脂肪毒性和胰岛功能障碍至关重要的脂质和蛋白质信号分子。最后，这些 IMS方法将被扩展到进行一项纵向研究，以确定从幼年到成年的器官发育过程中人胰岛细胞蛋白质和脂谱的差异，并确定这些生化变化如何与组织中的形态和结构变化相关。这些跨学科研究产生的分子图谱将提供对胰腺成熟和疾病进展中重要的细胞信号机制的见解，并将有助于设计新的治疗方法和策略，以维持胰岛的质量和功能。

 DESCRIPTION (provided by applicant): While hormone-secreting pancreatic islet cells (e.g.,  cells and ß cells) have been identified to play key roles in glucose homeostasis, our understanding of the processes important to normal pancreatic organogenesis and leading to altered metabolic states such as type 2 diabetes (T2D) is still limited. The low availability of human islets and the lack of experimental methods to comprehensively analyze islet cells and their tissue environments restrict our ability to map cell signaling pathways and metabolism. Despite substantial progress towards treatments and cures, much remains unknown about the specific signaling and damage pathways that contribute to ß-cell dysfunction. A more fundamental understanding of islet development and diabetes pathophysiology is required to help direct diagnoses, prognoses, treatments, and therapies and likely begins at the molecular level. In this way, novel biochemical understandings can be translated to insights on pancreatic development and disease progression, ultimately leading to the identification of new potential biomarkers and therapeutic targets. The proposed discovery-based research herein will provide molecular-level insight on pancreatic islet architecture, function, and development by combining a form of new molecular imaging technology, matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS), with existing validated approaches. This technology is well suited to measuring the complex array of molecular information (e.g., lipids and proteins) present in cellular tissue and provides for an untargeted measurement method, which is ideal for the discovery of new molecules important to pancreatic function. We aim to utilize such in situ tissue-based IMS techniques to develop much more complete molecular maps for the different pancreatic endocrine cell types, allowing us to gain insight as to the cell signaling pathways involved in pancreatic development and disease progression. These IMS techniques will be used to specifically define the lipid and protein molecular signatures of normal mouse islets and correlate these maps to functional changes observed in the presence of obesity and insulin resistance. This will allow us to establish those lipid and protein signaling molecules crucial to lipotoxicity and islet dysfunction in the well-studied ob/ob mouse model. Finally, these IMS approaches will be expanded to perform a longitudinal study identifying differences in protein and lipid profiles of human pancreatic islet cells throughout organogenetic development from the juvenile to the adult stages, and determining how these biochemical changes relate to morphological and architectural changes in the tissue. The molecular profiles produced by these interdisciplinary studies will provide insights on the cell signaling mechanisms important in pancreatic maturation and disease progression and will aid in the design of novel therapies and strategies to sustain islet mass and function.