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Bredum SK, Strathe AV, Jacobsen J, Christoffersen BØ, Gehre M, Kümmel S, Junghans P, Marcussen C. Quantifying energy expenditure in Göttingen Minipigs with the 13C-bicarbonate method under basal and drug-treated conditions. Clin Nutr ESPEN 2023; 58:388-396. [PMID: 38057031 DOI: 10.1016/j.clnesp.2023.10.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 10/25/2023] [Accepted: 10/30/2023] [Indexed: 12/08/2023]
Abstract
Effective treatments of obesity focusing on energy expenditure (EE) are needed. To evaluate future EE-modulating drug candidates, appropriate animal models and methods to assess EE are needed. This study aimed to evaluate the stable isotope 13C-bicarbonate method (13C-BM) for estimating EE in Göttingen minipigs under basal and drug-treated conditions. Four experiments (Expt.1-4) were conducted to assess: 1) the 13C-BM reproducibility using breath sample collection (n = 8), on two consecutive days, 2) the effect of two dose levels (5 and 10 mg/kg body weight (BW)) of the mitochondrial uncoupler dinitrophenol (DNP) in a crossover design (n = 8), 3) sampling method agreement; blood vs. exhaled air (n = 6) and 4) 13C-BM using constant isotope infusion compared with indirect calorimetry (IC) (n = 3). Results correlated significantly (p < 0.001) between days (Expt.1), with an average coefficient of variance of 5.4 ± 2.3%. Administration of 10 mg DNP/kg BW increased (p < 0.01) EE by 33.2 ± 6.4% (Expt.2). Results based on different sampling methods correlated significantly (p < 0.001) and EE increased after 10 mg DNP/kg BW (p < 0.05) in Expt.3. However, results based on blood sampling were significantly higher (p < 0.01) than those of exhaled air. No effect of DNP and significantly different EE results (p < 0.05) was observed in a limited number of animals, when constant isotope infusion and blood sampling was compared with IC (Expt.4). In conclusion, the 13C-BM is useful for investigating treatment effects on EE in minipigs. However, further validation under standardized conditions is needed to provide accurate estimates of the 13C recovery factor and respiratory quotient, both of decisive importance when using the 13C-BM.
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Affiliation(s)
- Simon K Bredum
- Department of Veterinary and Animal Sciences, University of Copenhagen, Denmark
| | - Anja V Strathe
- Department of Veterinary and Animal Sciences, University of Copenhagen, Denmark
| | | | | | - Matthias Gehre
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Steffen Kümmel
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Peter Junghans
- Research Institute for Farm Animal Biology (FBN), Institute of Nutritional Physiology 'Oskar Kellner', Dummerstorf, Germany
| | - Caroline Marcussen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Denmark.
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Liu D, Zhang Y, Gharavi R, Park HR, Lee J, Siddiqui S, Telljohann R, Nassar MR, Cutler RG, Becker KG, Mattson MP. The mitochondrial uncoupler DNP triggers brain cell mTOR signaling network reprogramming and CREB pathway up-regulation. J Neurochem 2015; 134:677-92. [PMID: 26010875 DOI: 10.1111/jnc.13176] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Revised: 05/07/2015] [Accepted: 05/13/2015] [Indexed: 12/13/2022]
Abstract
Mitochondrial metabolism is highly responsive to nutrient availability and ongoing activity in neuronal circuits. The molecular mechanisms by which brain cells respond to an increase in cellular energy expenditure are largely unknown. Mild mitochondrial uncoupling enhances cellular energy expenditure in mitochondria and can be induced with 2,4-dinitrophenol (DNP), a proton ionophore previously used for weight loss. We found that DNP treatment reduces mitochondrial membrane potential, increases intracellular Ca(2+) levels and reduces oxidative stress in cerebral cortical neurons. Gene expression profiling of the cerebral cortex of DNP-treated mice revealed reprogramming of signaling cascades that included suppression of the mammalian target of rapamycin (mTOR) and insulin--PI3K - MAPK pathways, and up-regulation of tuberous sclerosis complex 2, a negative regulator of mTOR. Genes encoding proteins involved in autophagy processes were up-regulated in response to DNP. CREB (cAMP-response element-binding protein) signaling, Arc and brain-derived neurotrophic factor, which play important roles in synaptic plasticity and adaptive cellular stress responses, were up-regulated in response to DNP, and DNP-treated mice exhibited improved performance in a test of learning and memory. Immunoblot analysis verified that key DNP-induced changes in gene expression resulted in corresponding changes at the protein level. Our findings suggest that mild mitochondrial uncoupling triggers an integrated signaling response in brain cells characterized by reprogramming of mTOR and insulin signaling, and up-regulation of pathways involved in adaptive stress responses, molecular waste disposal, and synaptic plasticity. Physiological bioenergetic challenges such as exercise and fasting can enhance neuroplasticity and protect neurons against injury and neurodegeneration. Here, we show that the mitochondrial uncoupling agent 2,4-dinitrophenol (DNP) elicits adaptive signaling responses in the cerebral cortex involving activation of Ca(2+) -CREB and autophagy pathways, and inhibition of mTOR and insulin signaling pathways. The molecular reprogramming induced by DNP, which is similar to that of exercise and fasting, is associated with improved learning and memory, suggesting potential therapeutic applications for DNP.
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Affiliation(s)
- Dong Liu
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, Maryland, USA
| | - Yongqing Zhang
- Gene Expression and Genomics Unit, National Institute on Aging Intramural Research Program, Baltimore, Maryland, USA
| | - Robert Gharavi
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, Maryland, USA
| | - Hee Ra Park
- Department of Pharmacy, College of Pharmacy, Molecular Inflammation Research Center for Aging Intervention, Pusan National University, Busan, Korea
| | - Jaewon Lee
- Department of Pharmacy, College of Pharmacy, Molecular Inflammation Research Center for Aging Intervention, Pusan National University, Busan, Korea
| | - Sana Siddiqui
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, Maryland, USA
| | - Richard Telljohann
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, Maryland, USA
| | - Matthew R Nassar
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, Maryland, USA
| | - Roy G Cutler
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, Maryland, USA
| | - Kevin G Becker
- Gene Expression and Genomics Unit, National Institute on Aging Intramural Research Program, Baltimore, Maryland, USA
| | - Mark P Mattson
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, Maryland, USA
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Goldgof M, Xiao C, Chanturiya T, Jou W, Gavrilova O, Reitman ML. The chemical uncoupler 2,4-dinitrophenol (DNP) protects against diet-induced obesity and improves energy homeostasis in mice at thermoneutrality. J Biol Chem 2014; 289:19341-50. [PMID: 24872412 DOI: 10.1074/jbc.m114.568204] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The chemical uncoupler 2,4-dinitrophenol (DNP) was an effective and widely used weight loss drug in the early 1930s. However, the physiology of DNP has not been studied in detail because toxicity, including hyperthermia and death, reduced interest in the clinical use of chemical uncouplers. To investigate DNP action, mice fed a high fat diet and housed at 30 °C (to minimize facultative thermogenesis) were treated with 800 mg/liter DNP in drinking water. DNP treatment increased energy expenditure by ∼ 17%, but did not change food intake. DNP-treated mice weighed 26% less than controls after 2 months of treatment due to decreased fat mass, without a change in lean mass. DNP improved glucose tolerance and reduced hepatic steatosis without observed toxicity. DNP treatment also reduced circulating T3 and T4 levels, Ucp1 expression, and brown adipose tissue activity, demonstrating that DNP-mediated heat generation substituted for brown adipose tissue thermogenesis. At 22 °C, a typical vivarium temperature that is below thermoneutrality, DNP treatment had no effect on body weight, adiposity, or glucose homeostasis. Thus, environmental temperature should be considered when assessing an anti-obesity drug in mice, particularly agents acting on energy expenditure. Furthermore, the beneficial effects of DNP suggest that chemical uncouplers deserve further investigation for the treatment of obesity and its comorbidities.
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Affiliation(s)
| | - Cuiying Xiao
- From the Diabetes, Endocrinology, and Obesity Branch and
| | - Tatyana Chanturiya
- the Mouse Metabolism Core, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
| | - William Jou
- the Mouse Metabolism Core, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
| | - Oksana Gavrilova
- the Mouse Metabolism Core, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
| | - Marc L Reitman
- From the Diabetes, Endocrinology, and Obesity Branch and
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De Felice FG, Ferreira ST. Novel neuroprotective, neuritogenic and anti-amyloidogenic properties of 2,4-dinitrophenol: the gentle face of Janus. IUBMB Life 2006; 58:185-91. [PMID: 16754295 DOI: 10.1080/15216540600702198] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
In Roman mythology, Janus was the god of gates, doors, beginnings and endings. He was usually depicted with two faces looking in opposite directions. Janus was frequently used to symbolize change and transitions, such as the progression from past to future or from one viewpoint to another. 2,4-dinitrophenol (DNP) and other nitrophenols have long been known to be toxic at high concentrations (the 'bad' face of DNP), an effect that appears essentially related to interference with cellular energy metabolism due to uncoupling of mitochondrial oxidative phosphorylation. Five years ago, however, we published the first report showing that low concentrations of DNP protect neurons against the toxicity of the amyloid-beta peptide (De Felice et al. (2001) FASEB J. 15:1297 - 1299]. Since then, other studies have provided evidence of beneficial actions of DNP (at low concentrations), including neuroprotection against different types of insult, blockade of amyloid aggregation, stimulation of neurite outgrowth and neuronal differentiation, and even extension of lifespan in certain organisms. Some of these effects appear to be due to mild mitochondrial uncoupling and prevention of cellular oxidative stress, whereas other actions are related to activation of additional intracellular signaling pathways. Thus, a novel and 'gentle' face of DNP is emerging from such studies. In this review, we discuss both toxic and beneficial actions of DNP. The evidence available so far suggests that DNP and other compounds with similar biological activities may be of significant interest to the development of novel therapeutic approaches for neurodegenerative diseases and other neurological disorders.
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Affiliation(s)
- Fernanda G De Felice
- Instituto de Bioquímica Médica, Programa de Bioquímica e Biofísica Celular, Universidade Federal do Rio de Janeiro, Brazil.
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Miller TL, Lorusso DJ, Deinzer ML. The acute toxicity of nonachloropredioxin and 3- and 4-hydroxynonachlorodiphenyl ether in mice. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH 1982; 10:699-707. [PMID: 7161822 DOI: 10.1080/15287398209530288] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The acute intraperitoneal LD50 values of hydroxynonachlorodiphenyl ethers (HO-Cl9-DPEs) in mice have been determined. The acute toxicity of each of these compounds is compared with that of pentachlorophenol (PCP) and 2-hydroxy-2',4,4'-trichlorodiphenyl ether (2-HO-Cl3-DPE; Irgasan DP-300; Triclosan), a commonly used bactericide. The order of acute toxicity observed was: 2-HO-Cl9-DPE greater than technical PCP approximately equal to pure PCP greater than 3-HO-Cl9-DPE greater than 4-HO-Cl9-DPE greater than 2-HO-Cl3-DPE. Symptomatology following exposure to the HO-Cl9-DPEs was similar to that observed for PCP, a known uncoupler of oxidative phosphorylation. 2-HO-Cl3-DPE, however, produced clinical signs suggestive of a suppressive effect on the central nervous system. Data on time response following a lethal dose of each of these compounds was also obtained.
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Clark WG, Clark YL. Changes in body temperature after administration of antipyretics, LSD, delta 9-THC, CNS depressants and stimulants, hormones, inorganic ions, gases, 2,4-DNP and miscellaneous agents. Neurosci Biobehav Rev 1981; 5:1-136. [PMID: 6112723 DOI: 10.1016/0149-7634(81)90039-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
This survey concludes a series of complications of data from the literature, primarily published since 1965, on thermoregulatory effects of antipyretics in afebrile as well as in febrile subjects, LSD and other hallucinogens, cannabinoids, general CNS depressants, CNS stimulants including xanthines, hormones, inorganic ions, gases and fumes, 2,4-dinitrophenol and miscellaneous agents including capsaicin, cardiac glycosides, chemotherapeutic agents, cinchona alkaloids, cyclic nucleotides, cycloheximide, 2-deoxy-D-glucose, dimethylsulfoxide, insecticides, local anesthetics, poly I:poly C, spermidine and spermine, sugars, toxins and transport inhibitors. The information listed includes the species used, route of administration and dose of drug, the environmental temperature at which the experiments were performed, the number of tests, the direction and magnitude of body temperature change and remarks on the presence of special conditions such as age or lesions, or on the influence of other drugs, such as antagonists, on the response to the primary agents.
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Nakaue HS, Dost FN, Buhler DR. Studies on the toxicity of hexachlorophene in the rat. Toxicol Appl Pharmacol 1973; 24:239-49. [PMID: 4696307 DOI: 10.1016/0041-008x(73)90144-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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