A genetically-encoded sensor for imaging intracellular fatty acids

描述（由申请人提供）：脂质的储存和动员是在后生动物进化过程中保守的基本细胞过程，几乎存在于所有哺乳动物细胞中。细胞内FFA （FFAi）通常受到严格控制，因为过量的FFAi是有毒的。事实上，细胞内FFA和FFA代谢物的过度积累导致细胞功能障碍，称为“脂肪毒性”，这被认为是肥胖导致糖尿病和心血管疾病的主要手段。因此，了解细胞如何吸收、动员和引导游离脂肪酸是一个重要的生物学问题，对健康和疾病具有广泛的影响。细胞内游离脂肪酸的摄取和动员似乎具有重要的时间和空间域。尽管如此，由于细胞内FFA水平目前无法成像，因此对活细胞内FFA代谢“何时何地”发生的调查尚不可能。因此，R21应用的目的是开发和实现具有高空间和时间分辨率的FFAi光学传感器，用于生物应用。该传感器被设计用作一般的细胞质传感器，或者可以专门针对提出的FFA摄取，动员和氧化的亚细胞位点。我们预计一个经过验证的传感器将有广泛的应用，并将导致对细胞脂质运输生物学的新见解。

DESCRIPTION (provided by applicant): The storage and mobilization of lipid are fundamental cellular processes that are conserved throughout metazoan evolution and are present in virtually all mammalian cells. Intracellular FFA (FFAi) are normally kept under tight control since excessive FFAi are toxic. Indeed, excessive accumulation of intracellular FFA and FFA metabolites leads to cellular dysfunction, termed 'lipotoxicity', which is thought to be a major means by which obesity contributes to diabetes and cardiovascular disease. Thus, a mechanistic understanding of how cells assimilate, mobilize and channel FFA is an important biological question with broad implications for health and disease. The uptake and mobilization of FFA within cells appear to have important temporal and spatial domains. Nonetheless, investigation of the "when and where" FFA metabolism occurs within live cells has not been possible because intracellular FFA levels cannot presently be imaged. Therefore, the aim of the R21 application is to develop and implement an optical sensor of FFAi having high spatial and temporal resolution for biological applications. This sensor is designed to be used as a general cytosolic sensor, or can be specifically targeted to proposed subcellular sites of FFA uptake, mobilization and oxidation. We anticipate that a validated sensor will have wide applications and will lead to new insights into biology of cellular lipid trafficking. PUBLIC HEALTH RELEVANCE: The storage and mobilization of lipid are fundamental cellular processes that are present in virtually all mammalian cells. Intracellular FFA (FFAi) are normally kept under tight control and since excessive FFAi are toxic and can contribute to obesity-related diabetes and cardiovascular disease. Thus, a mechanistic understanding of how cells assimilate, mobilize and channel FFA is an important biological question with broad implications for health and disease. Evidence indicates that the uptake and mobilization of FFA within cells has important temporal and spatial domains, however, analysis of these dynamics has not been difficult because intracellular FFA levels cannot presently be imaged. Therefore, the aim of the R21 application is to develop and implement an optical sensor of intracellular FFA with high spatial and temporal resolution for biological applications. This sensor can be used as a general cytosolic sensor, or can be specifically targeted to key subcellular sites of FFA uptake, mobilization and oxidation. We anticipate that a validated sensor will have wide applications and will lead to new insights into biology of cellular lipid trafficking.