@article{126ea3a34b5343f0a91a71d2c1a0b26f,
title = "A Ratiometric Sensor for Imaging Insulin Secretion in Single β Cells",
abstract = "Despite the urgent need for assays to visualize insulin secretion there is to date no reliable method available for measuring insulin release from single cells. To address this need, we developed a genetically encoded reporter termed RINS1 based on proinsulin superfolder GFP (sfGFP) and mCherry fusions for monitoring insulin secretion. RINS1 expression in MIN6 β cells resulted in proper processing yielding single-labeled insulin species. Unexpectedly, glucose or drug stimulation of insulin secretion in β cells led to the preferential release of the insulin-sfGFP construct, while the mCherry-fused C-peptide remained trapped in exocytic granules. This physical separation was used to monitor glucose-stimulated insulin secretion ratiometrically by total internal reflection fluorescence microscopy in single MIN6 and primary mouse β cells. Further, RINS1 enabled parallel monitoring of pulsatile insulin release in tolbutamide-treated β cells, demonstrating the potential of RINS1 for investigations of antidiabetic drug candidates at the single-cell level.",
keywords = "TIRF, biosensor, calcium, fluorescence, glucose, granule, insulin, mCherry, oscillation, potassium channel, superfolder GFP, tolbutamide",
author = "Martina Schifferer and Yushchenko, {Dmytro A.} and Frank Stein and Andrey Bolbat and Carsten Schultz",
note = "Funding Information: All authors acknowledge funding by the EMBL . M.S. and D.A.Y. were fellows of the EMBL Interdisciplinary Postdoc Program, partly funded by the EU Marie-Curie Program (EU grant 229597 for D.A.Y.). D.A.Y. was also supported by an IOCB installation grant. C.S. is grateful for support by TRR186 , funded by the DFG . We thank the Advanced Light Microscopy Facility (ALMF) at EMBL for professional support, to the laboratory of Alexander Aulehla for providing access to mice, as well as Nicole Heath and Andr{\'e} Nadler for critical reading of the manuscript. Funding Information: All authors acknowledge funding by the EMBL. M.S. and D.A.Y. were fellows of the EMBL Interdisciplinary Postdoc Program, partly funded by the EU Marie-Curie Program (EU grant 229597 for D.A.Y.). D.A.Y. was also supported by an IOCB installation grant. C.S. is grateful for support by TRR186, funded by the DFG (Massachusetts Department of Fish and Game). We thank the Advanced Light Microscopy Facility (ALMF) at EMBL for professional support, to the laboratory of Alexander Aulehla for providing access to mice, as well as Nicole Heath and Andr{\'e} Nadler for critical reading of the manuscript. Publisher Copyright: {\textcopyright} 2017 The Authors",
year = "2017",
month = apr,
day = "20",
doi = "10.1016/j.chembiol.2017.03.001",
language = "English (US)",
volume = "24",
pages = "525--531.e4",
journal = "Cell Chemical Biology",
issn = "2451-9456",
publisher = "Elsevier Inc.",
number = "4",
}