1. Biochemistry and Chemical Biology
  2. Physics of Living Systems

Optical estimation of absolute membrane potential using fluorescence lifetime imaging

  1. Julia Rose Lazzari-Dean
  2. Anneliese M M Gest
  3. Evan W Miller  Is a corresponding author
  1. University of California, Berkeley, United States
https://doi.org/10.7554/eLife.44522
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  1. Julia Rose Lazzari-Dean
  2. Anneliese M M Gest
  3. Evan W Miller
(2019)
Optical estimation of absolute membrane potential using fluorescence lifetime imaging
eLife 8:e44522.
https://doi.org/10.7554/eLife.44522
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Abstract

All cells maintain ionic gradients across their plasma membranes, producing transmembrane potentials (Vmem). Mounting evidence suggests a relationship between resting Vmem and the physiology of non-excitable cells with implications in diverse areas, including cancer, cellular differentiation, and body patterning. A lack of non-invasive methods to record absolute Vmem limits our understanding of this fundamental signal. To address this need, we developed a fluorescence lifetime-based approach (VF-FLIM) to visualize and optically quantify Vmem with single-cell resolution in mammalian cell culture. Using VF-FLIM, we report Vmem distributions over thousands of cells, a 100-fold improvement relative to electrophysiological approaches. In human carcinoma cells, we visualize the voltage response to growth factor stimulation, stably recording a 10-15 mV hyperpolarization over minutes. Using pharmacological inhibitors, we identify the source of the hyperpolarization as the Ca2+-activated K+ channel KCa3.1. The ability to optically quantify absolute Vmem with cellular resolution will allow a re-examination of its signaling roles.

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All data presented in the manuscript is available in the supporting / supplementary information.

Article and author information

Author details

  1. Julia Rose Lazzari-Dean

    Department of Chemistry, University of California, Berkeley, Berkeley, United States
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-2971-5379

  2. Anneliese M M Gest

    Department of Chemistry, University of California, Berkeley, Berkeley, United States
    Competing interests
    No competing interests declared.

  3. Evan W Miller

    Department of Chemistry, University of California, Berkeley, Berkeley, United States
    For correspondence
    evanwmiller@berkeley.edu
    Competing interests
    Evan W Miller, is listed as an inventor on a patent describing voltage-sensitive fluorophores. This patent (US20170315059) is owned by the Regents of the University of California.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-6556-7679

Funding

National Science Foundation (GRFP)

  • Julia Rose Lazzari-Dean

National Institutes of Health (R35GM119855)

  • Evan W Miller

Alfred P. Sloan Foundation (FG-2016-6359)

  • Evan W Miller

March of Dimes Foundation (5-FY-16-65)

  • Evan W Miller

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Copyright

© 2019, Lazzari-Dean et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Julia Rose Lazzari-Dean
  2. Anneliese M M Gest
  3. Evan W Miller
(2019)
Optical estimation of absolute membrane potential using fluorescence lifetime imaging
eLife 8:e44522.
https://doi.org/10.7554/eLife.44522

Share this article

https://doi.org/10.7554/eLife.44522

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