Next Article in Journal
Electric and Magnetic Field-Assisted Orientational Transitions in the Ensembles of Domains in a Nematic Liquid Crystal on the Polymer Surface
Next Article in Special Issue
Intrinsic Tryptophan Fluorescence in the Detection and Analysis of Proteins: A Focus on Förster Resonance Energy Transfer Techniques
Previous Article in Journal
Atrazine Affects Phosphoprotein and Protein Expression in MCF-10A Human Breast Epithelial Cells
Previous Article in Special Issue
Quantitative Analysis of Tau-Microtubule Interaction Using FRET
Article Menu
Issue 10 (October) cover image

Export Article

Open AccessArticle
Int. J. Mol. Sci. 2014, 15(10), 17827-17837;

Insulin Induces an Increase in Cytosolic Glucose Levels in 3T3-L1 Cells with Inhibited Glycogen Synthase Activation

Celica, Biomedical, Tehnološki park 24, 1000 Ljubljana, Slovenia
Laboratory for Neuroendocrinology–Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia
Department of Physical Performance, Norwegian School of Sports Sciences, P.O. Box N-4014 Ullevål Stadion, 0806 Oslo, Norway
Author to whom correspondence should be addressed.
Received: 22 July 2014 / Revised: 18 September 2014 / Accepted: 19 September 2014 / Published: 2 October 2014
(This article belongs to the Special Issue Förster Resonance Energy Transfer (FRET) 2015)
Full-Text   |   PDF [388 KB, uploaded 2 October 2014]   |  


Glucose is an important source of energy for mammalian cells and enters the cytosol via glucose transporters. It has been thought for a long time that glucose entering the cytosol is swiftly phosphorylated in most cell types; hence the levels of free glucose are very low, beyond the detection level. However, the introduction of new fluorescence resonance energy transfer-based glucose nanosensors has made it possible to measure intracellular glucose more accurately. Here, we used the fluorescent indicator protein (FLIPglu-600µ) to monitor cytosolic glucose dynamics in mouse 3T3-L1 cells in which glucose utilization for glycogen synthesis was inhibited. The results show that cells exhibit a low resting cytosolic glucose concentration. However, in cells with inhibited glycogen synthase activation, insulin induced a robust increase in cytosolic free glucose. The insulin-induced increase in cytosolic glucose in these cells is due to an imbalance between the glucose transported into the cytosol and the use of glucose in the cytosol. In untreated cells with sensitive glycogen synthase activation, insulin stimulation did not result in a change in the cytosolic glucose level. This is the first report of dynamic measurements of cytosolic glucose levels in cells devoid of the glycogen synthesis pathway. View Full-Text
Keywords: glucose; FRET; nanosensor; 3T3-L1 fibroblast; insulin; glycogen glucose; FRET; nanosensor; 3T3-L1 fibroblast; insulin; glycogen

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Chowdhury, H.H.; Kreft, M.; Jensen, J.; Zorec, R. Insulin Induces an Increase in Cytosolic Glucose Levels in 3T3-L1 Cells with Inhibited Glycogen Synthase Activation. Int. J. Mol. Sci. 2014, 15, 17827-17837.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Int. J. Mol. Sci. EISSN 1422-0067 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top