Bittner Carla X, Loaiza Anitsi, Ruminot Iván, Larenas Valeria, Sotelo-Hitschfeld Tamara, Gutiérrez Robin, Córdova Alex, Valdebenito Rocío, Frommer Wolf B, Barros L Felipe
Centro de Estudios Científicos Valdivia, Chile.
Front Neuroenergetics. 2010 Sep 15;2. doi: 10.3389/fnene.2010.00026. eCollection 2010.
The glycolytic rate is sensitive to physiological activity, hormones, stress, aging, and malignant transformation. Standard techniques to measure the glycolytic rate are based on radioactive isotopes, are not able to resolve single cells and have poor temporal resolution, limitations that hamper the study of energy metabolism in the brain and other organs. A new method is described in this article, which makes use of a recently developed FRET glucose nanosensor to measure the rate of glycolysis in single cells with high temporal resolution. Used in cultured astrocytes, the method showed for the first time that glycolysis can be activated within seconds by a combination of glutamate and K(+), supporting a role for astrocytes in neurometabolic and neurovascular coupling in the brain. It was also possible to make a direct comparison of metabolism in neurons and astrocytes lying in close proximity, paving the way to a high-resolution characterization of brain energy metabolism. Single-cell glycolytic rates were also measured in fibroblasts, adipocytes, myoblasts, and tumor cells, showing higher rates for undifferentiated cells and significant metabolic heterogeneity within cell types. This method should facilitate the investigation of tissue metabolism at the single-cell level and is readily adaptable for high-throughput analysis.
糖酵解速率对生理活动、激素、应激、衰老和恶性转化敏感。测量糖酵解速率的标准技术基于放射性同位素，无法分辨单个细胞且时间分辨率较差，这些局限性阻碍了对大脑和其他器官能量代谢的研究。本文描述了一种新方法，该方法利用最近开发的荧光共振能量转移（FRET）葡萄糖纳米传感器以高时间分辨率测量单个细胞中的糖酵解速率。在培养的星形胶质细胞中使用该方法，首次表明谷氨酸和钾离子（K⁺）的组合可在数秒内激活糖酵解，支持星形胶质细胞在大脑神经代谢和神经血管耦合中的作用。还能够直接比较紧邻的神经元和星形胶质细胞的代谢情况，为大脑能量代谢的高分辨率表征铺平了道路。在成纤维细胞、脂肪细胞、成肌细胞和肿瘤细胞中也测量了单细胞糖酵解速率，结果显示未分化细胞的糖酵解速率更高，且细胞类型内存在显著的代谢异质性。该方法应有助于在单细胞水平研究组织代谢，并且易于适用于高通量分析。
