Genotoxic Responses of Mitochondrial Oxygen Consumption Rate and Mitochondrial Semiquinone Radicals in Tumor Cells

Kumiko Yamamoto, Hironobu Yasui, Tomoki Bo, Tohru Yamamori, Wakako Hiraoka, Toshihide Yamasaki, Ken-Ichi Yamada, Osamu Inanami

研究成果: ジャーナルへの寄稿記事

3 引用 (Scopus)

抄録

Our recent report demonstrated that genotoxic stimuli enhance mitochondrial energy metabolism in various tumor cell lines. However, the mitochondrial response against genotoxic stimuli has not been fully elucidated. In this study, to investigate mitochondrial functions in X-irradiated cells, the oxygen consumption rate (OCR) in human cervical adenocarcinoma HeLa cells was examined by electron spin resonance (ESR) spectroscopy with lithium 5,9,14,18,23,27,32,36-octa-n-butoxy-2,3-naphthalocyanine. ESR oximetry demonstrated that basal respiration, ATP-linked respiration, proton leak, maximal respiration, and reserve capacity increased in HeLa cells 24 h after X-irradiation. However, a flow cytometric analysis using MitoTracker Green showed that mitochondrial mass also increased following X-irradiation. When the OCR was standardized to the mitochondria membrane mass, the radiation-induced increases in the respiratory parameters disappeared. This finding indicated that the radiation-induced increase in cellular OCR was explained by an increase in mitochondrial mass but not by the activation of mitochondrial respiratory-related enzymes. In addition, mitochondrial semiquinone radicals at g = 2.004 were detected by low-temperature (110 K) ESR spectroscopy. The ESR signal intensity of semiquinone radicals was enhanced by X-irradiation, suggesting an increase in the electron flow in the electron transport chain. These data will be important to understand the mechanism of radio-sensitization by mitochondria-targeting reagents in tumor cells.

元の言語英語
ページ(範囲)837-851
ページ数15
ジャーナルApplied Magnetic Resonance
49
発行部数8
DOI
出版物ステータス出版済み - 8 1 2018

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oxygen consumption
electron paramagnetic resonance
respiration
tumors
mitochondria
stimuli
irradiation
oximetry
adenosine triphosphate
metabolism
radiation
cells
cultured cells
spectroscopy
reagents
enzymes
electrons
lithium
activation
membranes

All Science Journal Classification (ASJC) codes

  • Atomic and Molecular Physics, and Optics

これを引用

Genotoxic Responses of Mitochondrial Oxygen Consumption Rate and Mitochondrial Semiquinone Radicals in Tumor Cells. / Yamamoto, Kumiko; Yasui, Hironobu; Bo, Tomoki; Yamamori, Tohru; Hiraoka, Wakako; Yamasaki, Toshihide; Yamada, Ken-Ichi; Inanami, Osamu.

:: Applied Magnetic Resonance, 巻 49, 番号 8, 01.08.2018, p. 837-851.

研究成果: ジャーナルへの寄稿記事

Yamamoto, Kumiko ; Yasui, Hironobu ; Bo, Tomoki ; Yamamori, Tohru ; Hiraoka, Wakako ; Yamasaki, Toshihide ; Yamada, Ken-Ichi ; Inanami, Osamu. / Genotoxic Responses of Mitochondrial Oxygen Consumption Rate and Mitochondrial Semiquinone Radicals in Tumor Cells. :: Applied Magnetic Resonance. 2018 ; 巻 49, 番号 8. pp. 837-851.
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