In vivoglucose imaging in multiple model organisms with an engineered single-wavelength sensor

Abstract

Glucose is arguably the most important molecule in metabolism, and its mismanagement underlies diseases of vast societal import, most notably diabetes. Although glucose-related metabolism has been the subject of intense study for over a century, tools to track glucose in living organisms with high spatio-temporal resolution are lacking. We describe the engineering of a family of genetically encoded glucose sensors with high signal-to-noise ratio, fast kinetics and affinities varying over four orders of magnitude (1 µM to 10 mM). The sensors allow rigorous mechanistic characterization of glucose transporters expressed in cultured cells with high spatial and temporal resolution. Imaging of neuron/glia co-cultures revealed ∼3-fold higher glucose changes in astrocytes versus neurons. In larvalDrosophilacentral nervous system explants, imaging of intracellular neuronal glucose suggested a novel rostro-caudal transport pathway in the ventral nerve cord neuropil, with paradoxically slower uptake into the peripheral cell bodies and brain lobes. In living zebrafish, expected glucose-related physiological sequelae of insulin and epinephrine treatments were directly visualized in real time. Additionally, spontaneous muscle twitches induced glucose uptake in muscle, and sensory- and pharmacological perturbations gave rise to large but enigmatic changes in the brain. These sensors will enable myriad experiments, most notably rapid, high-resolution imaging of glucose influx, efflux, and metabolism in behaving animals.

AAV-Txnip prolongs cone survival and vision in mouse models of retinitis pigmentosa

“…lower F PercevalHR 488:405 ) in high glucose medium (Figure 4A,B). To further probe whether intracellular glucose was reduced after overexpression of Txnip (Wu et al, 2013), a glucose sensor iGlucoSnFR was used (Keller et al, 2019). This sensor showed reduced intracellular glucose in Txnip-transduced cones (Figure 4-figure supplement 1A,B).…”

AAV-Txnip prolongs cone survival and vision in mouse models of retinitis pigmentosa

“…4a,b). To further probe whether intracellular glucose was reduced after overexpression of Txnip (Wu et al, 2013), a glucose sensor iGlucoSnFR was used (Keller et al, 2019). This sensor showed reduced intracellular glucose in Txnip-treated cones (Extended Data Fig.…”

Multiplexed Optical Sensors in Arrayed Islands of Cells for multimodal recordings of cellular physiology

“…Looking forward, the MOSAIC platform will grow as new and improved fluorescent sensors become available. For example, an improved pH ratiometric sensor 58 , more sensitive glucose sensor 59 , and ATP sensors targeted to the ER and mitochondria 60 are anticipated enhancements. A natural future direction would be to add additional reporters of second messengers such as cyclic AMP (e.g., ref.…”