DNP-enhanced Tissue HRMAS MRS - Towards Measurements of Single-Cell Metabolomics

描述（由申请人提供）：拟议的研究重点是开发DNP增强的高分辨率魔角旋转（HRMAS）磁共振波谱（MRS），以量化完整前列腺组织内的细胞代谢。这将允许 研究显微解剖的纯病理学特征，由于该方法的灵敏度限制，目前还不可能。使用DNP，可以显著增强NMR/MRS实验中固有的小信号强度。近年来，DNP已被证明是一种在世界各地实验室的NMR实验中增加信号强度的稳健方法，并且在使DNP适应溶液状态NMR光谱方面取得了实质性进展。通过DNP（> 80）可获得的增强与可以从冷冻探针预期的灵敏度增益形成较大对比。然而，由于（人类）组织具有相应的固体和溶液状态NMR样品的特性，必须开发特定的技术，使DNP的优势HRMAS MRS的组织研究。我们建议开发新的仪器和方法DNP增强HRMAS实验。组织样本将被原位极化，并且该方法允许连续信号采集。由于样品特征主要是溶液样品的特征，因此将使用奥弗豪泽效应（OE）对样品进行分析。众所周知，高场OE实验遭受严重的样品加热，因此，我们建议使用OE的变体，其可以将样品暴露于的THz功率的量减少>250倍。虽然该项目的第一阶段被设计为概念验证研究，但我们预计在该提案的第二阶段期间信号增强>10。这项技术的成功开发将使DNP增强的HRMAS MRS实验快速扩散，以研究显微解剖的纯病理特征，这将对美国国立卫生研究院资助的许多项目产生巨大兴趣。

DESCRIPTION (provided by applicant): The proposed research focuses on the development DNP-enhanced high-resolution magic-angle-spinning (HRMAS) magnetic resonance spectroscopy (MRS) to quantify cellular metabolities within intact prostate tissue. This will allow the study of micro-dissected pure pathological features, which is currently not possible due to the sensitivity limitations of the method. With DNP, the inherently small signal intensities in an NMR/MRS experiment can be drastically enhanced. In recent years, DNP has proven to be a robust method to increase signal intensities in NMR experiments in laboratories around the world and substantial progress has been made in adapting DNP for solution-state NMR spectroscopy. The enhancements available through DNP (> 80) are in Iarge contrast to the sensitivity gain that can be expected from a cryo-probe. However, since (human) tissue has the characteristics corresponding of solid and solution-state NMR samples, specific technology has to be developed to bring the advantage of DNP to HRMAS MRS for tissue studies. We propose to develop novel instrumentation and methodology for DNP-enhanced HRMAS experiments. The tissue sample will be polarized in-situ and the method allows for continuous signal acquisition. Since the sample characteristics is predominantly that of a solution sample, the Overhauser Effect (OE) will be used to polarize the sample. It is know that high-field OE experiments suffer from severe sample heating, therefore, we propose to use a variant of the OE that can reduce the amount of THz power the sample is exposed to by factor >250. While Phase I of this project is designed as a proof-of-concept study, we expect signal enhancements of >10 during Phase II of this proposal. The successful development of this technology will allow rapid proliferation of DNP-enhanced HRMAS MRS experiments to study micro-dissected pure pathological features, which will be of large interest to many projects funded by the U.S. National Institutes of Health.