UCP2- and non-UCP2-mediated electric current in eukaryotic cells exhibits different properties.
Using live eukaryotic cells, including cancer cells, MCF-7 and HCT-116, normal hepatocytes and red blood cells in anode and potassium ferricyanide in cathode of MFC could generate bio-based electric current. Electrons and protons generated from the metabolic reaction in both cytosol and mitochondria contributing to the leaking would mediate the generation of electric current. Both resveratrol (RVT) and 2,4-dinitrophenol (DNP) used to induce proton leak in mitochondria were found to promote electric current production in all cells except red blood cells without mitochondria. Proton leak might be important for electric current production by bringing the charge balance in cells to enhance the further electron leak. The induced electric current by RVT can be blocked by Genipin, an inhibitor of UCP2-mediated proton leak, while that induced by DNP cannot. RVT could reduce reactive oxygen species (ROS) level in cells better than that of DNP. In addition, RVT increased mitochondrial membrane potential (MMP), while DNP decreased it. Results highly suggested the existence of at least two types of electric current that showed different properties. They included UCP2-mediated and non-UCP2-mediated electric current. UCP2-mediated electric current exhibited higher reactive oxygen species (ROS) reduction effect per unit electric current production than that of non-UCP2-mediated electric current. Higher UCP2-mediated electric current observed in cancer cells might contribute to the mechanism of drug resistence. Correlation could not be established between electric current production with either ROS and MMP without distinguishing the types of electric current.
Department of Gastroenterology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital South Campus, 6600 Nanfeng Road, Fengxian District, Shanghai, China, 201499. ruihuawang@vip.163.com.
Ruihua
R
Wang
Program of Food Science and Technology, Division of Science and Technology, BNU-HKBU United International College, 28 Jinfeng Road, Tangjiawan, Zhuhai, Guangdong, China, 519085. kcmoyung@uic.edu.hk.
K C
KC
MoYung
Program of Food Science and Technology, Division of Science and Technology, BNU-HKBU United International College, 28 Jinfeng Road, Tangjiawan, Zhuhai, Guangdong, China, 519085.
M H
MH
Zhang
Program of Food Science and Technology, Division of Science and Technology, BNU-HKBU United International College, 28 Jinfeng Road, Tangjiawan, Zhuhai, Guangdong, China, 519085. karenpoon@uic.edu.hk.
Karen
K
Poon
D019297:2,4-Dinitrophenol / Q000494:pharmacology; D000818:Animals; D004560:Electricity; D004566:Electrodes; D004579:Electron Transport; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism; D005057:Eukaryotic Cells / Q000187:drug effects* / Q000378:metabolism; D045325:HCT116 Cells; D022781:Hepatocytes / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007473:Ion Channels / Q000378:metabolism*; D039823:Iridoids / Q000494:pharmacology; D061986:MCF-7 Cells; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects*; D051379:Mice; D024101:Mitochondrial Proteins / Q000378:metabolism*; D011522:Protons; D011817:Rabbits; D017382:Reactive Oxygen Species / Q000378:metabolism; D000077185:Resveratrol; D013267:Stilbenes / Q000494:pharmacology; D000071246:Uncoupling Protein 2
D007473:Ion Channels; D039823:Iridoids; D024101:Mitochondrial Proteins; D011522:Protons; D017382:Reactive Oxygen Species; D013267:Stilbenes; C000604389:UCP2 protein, human; C000604390:Ucp2 protein, mouse; D000071246:Uncoupling Protein 2; C007834:genipin; D019297:2,4-Dinitrophenol; D000077185:Resveratrol
2,4-Dinitrophenol; Cellular electric current; Electron and proton leak; Genipin; Microbial fuel cell; Resveratrol