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A coarse-grained NADH redox model enables inference of subcellular metabolic fluxes from fluorescence lifetime imaging

Mitochondrial metabolism is of central importance to diverse aspects of cell and developmental biology. Defects in mitochondria are associated with many diseases, including cancer, neuropathology, and infertility. Our understanding of mitochondrial metabolism in situ and dysfunction in diseases are...

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Detalles Bibliográficos
Autores principales: Yang, Xingbo, Ha, Gloria, Needleman, Daniel J
Formato: Online Artículo Texto
Lenguaje:English
Publicado: eLife Sciences Publications, Ltd 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8935353/
https://www.ncbi.nlm.nih.gov/pubmed/34806591
http://dx.doi.org/10.7554/eLife.73808
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author Yang, Xingbo
Ha, Gloria
Needleman, Daniel J
author_facet Yang, Xingbo
Ha, Gloria
Needleman, Daniel J
author_sort Yang, Xingbo
collection PubMed
description Mitochondrial metabolism is of central importance to diverse aspects of cell and developmental biology. Defects in mitochondria are associated with many diseases, including cancer, neuropathology, and infertility. Our understanding of mitochondrial metabolism in situ and dysfunction in diseases are limited by the lack of techniques to measure mitochondrial metabolic fluxes with sufficient spatiotemporal resolution. Herein, we developed a new method to infer mitochondrial metabolic fluxes in living cells with subcellular resolution from fluorescence lifetime imaging of NADH. This result is based on the use of a generic coarse-grained NADH redox model. We tested the model in mouse oocytes and human tissue culture cells subject to a wide variety of perturbations by comparing predicted fluxes through the electron transport chain (ETC) to direct measurements of oxygen consumption rate. Interpreting the fluorescence lifetime imaging microscopy measurements of NADH using this model, we discovered a homeostasis of ETC flux in mouse oocytes: perturbations of nutrient supply and energy demand of the cell do not change ETC flux despite significantly impacting NADH metabolic state. Furthermore, we observed a subcellular spatial gradient of ETC flux in mouse oocytes and found that this gradient is primarily a result of a spatially heterogeneous mitochondrial proton leak. We concluded from these observations that ETC flux in mouse oocytes is not controlled by energy demand or supply, but by the intrinsic rates of mitochondrial respiration.
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spelling pubmed-89353532022-03-22 A coarse-grained NADH redox model enables inference of subcellular metabolic fluxes from fluorescence lifetime imaging Yang, Xingbo Ha, Gloria Needleman, Daniel J eLife Biochemistry and Chemical Biology Mitochondrial metabolism is of central importance to diverse aspects of cell and developmental biology. Defects in mitochondria are associated with many diseases, including cancer, neuropathology, and infertility. Our understanding of mitochondrial metabolism in situ and dysfunction in diseases are limited by the lack of techniques to measure mitochondrial metabolic fluxes with sufficient spatiotemporal resolution. Herein, we developed a new method to infer mitochondrial metabolic fluxes in living cells with subcellular resolution from fluorescence lifetime imaging of NADH. This result is based on the use of a generic coarse-grained NADH redox model. We tested the model in mouse oocytes and human tissue culture cells subject to a wide variety of perturbations by comparing predicted fluxes through the electron transport chain (ETC) to direct measurements of oxygen consumption rate. Interpreting the fluorescence lifetime imaging microscopy measurements of NADH using this model, we discovered a homeostasis of ETC flux in mouse oocytes: perturbations of nutrient supply and energy demand of the cell do not change ETC flux despite significantly impacting NADH metabolic state. Furthermore, we observed a subcellular spatial gradient of ETC flux in mouse oocytes and found that this gradient is primarily a result of a spatially heterogeneous mitochondrial proton leak. We concluded from these observations that ETC flux in mouse oocytes is not controlled by energy demand or supply, but by the intrinsic rates of mitochondrial respiration. eLife Sciences Publications, Ltd 2021-11-22 /pmc/articles/PMC8935353/ /pubmed/34806591 http://dx.doi.org/10.7554/eLife.73808 Text en © 2021, Yang et al https://creativecommons.org/licenses/by/4.0/This article is distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use and redistribution provided that the original author and source are credited.
spellingShingle Biochemistry and Chemical Biology
Yang, Xingbo
Ha, Gloria
Needleman, Daniel J
A coarse-grained NADH redox model enables inference of subcellular metabolic fluxes from fluorescence lifetime imaging
title A coarse-grained NADH redox model enables inference of subcellular metabolic fluxes from fluorescence lifetime imaging
title_full A coarse-grained NADH redox model enables inference of subcellular metabolic fluxes from fluorescence lifetime imaging
title_fullStr A coarse-grained NADH redox model enables inference of subcellular metabolic fluxes from fluorescence lifetime imaging
title_full_unstemmed A coarse-grained NADH redox model enables inference of subcellular metabolic fluxes from fluorescence lifetime imaging
title_short A coarse-grained NADH redox model enables inference of subcellular metabolic fluxes from fluorescence lifetime imaging
title_sort coarse-grained nadh redox model enables inference of subcellular metabolic fluxes from fluorescence lifetime imaging
topic Biochemistry and Chemical Biology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8935353/
https://www.ncbi.nlm.nih.gov/pubmed/34806591
http://dx.doi.org/10.7554/eLife.73808
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