1
|
Chen SY, Telfser AJ, Olzomer EM, Vancuylenberg CS, Zhou M, Beretta M, Li C, Alexopoulos SJ, Turner N, Byrne FL, Santos W, Hoehn KL. Beneficial effects of simultaneously targeting calorie intake and calorie efficiency in diet-induced obese mice. Clin Sci (Lond) 2024; 138:173-187. [PMID: 38315575 PMCID: PMC10876416 DOI: 10.1042/cs20231016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 01/16/2024] [Accepted: 02/05/2024] [Indexed: 02/07/2024]
Abstract
Semaglutide is an anti-diabetes and weight loss drug that decreases food intake, slows gastric emptying, and increases insulin secretion. Patients begin treatment with low-dose semaglutide and increase dosage over time as efficacy plateaus. With increasing dosage, there is also greater incidence of gastrointestinal side effects. One reason for the plateau in semaglutide efficacy despite continued low food intake is due to compensatory actions whereby the body becomes more metabolically efficient to defend against further weight loss. Mitochondrial uncoupler drugs decrease metabolic efficiency, therefore we sought to investigate the combination therapy of semaglutide with the mitochondrial uncoupler BAM15 in diet-induced obese mice. Mice were fed high-fat western diet (WD) and stratified into six treatment groups including WD control, BAM15, low-dose semaglutide without or with BAM15, and high-dose semaglutide without or with BAM15. Combining BAM15 with either semaglutide dose decreased body fat and liver triglycerides, which was not achieved by any monotherapy, while high-dose semaglutide with BAM15 had the greatest effect on glucose homeostasis. This study demonstrates a novel approach to improve weight loss without loss of lean mass and improve glucose control by simultaneously targeting energy intake and energy efficiency. Such a combination may decrease the need for semaglutide dose escalation and hence minimize potential gastrointestinal side effects.
Collapse
Affiliation(s)
- Sing-Young Chen
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Aiden J. Telfser
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Ellen M. Olzomer
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Calum S. Vancuylenberg
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Mingyan Zhou
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Martina Beretta
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Catherine Li
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Stephanie J. Alexopoulos
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Nigel Turner
- Cellular Bioenergetics Laboratory, Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
- School of Biomedical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Frances L. Byrne
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Webster L. Santos
- Department of Chemistry and Virginia Tech Centre for Drug Discovery, Virginia Tech, Blacksburg, VA 24061, U.S.A
| | - Kyle L. Hoehn
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| |
Collapse
|
2
|
Dwivedi SK, Arachchige DL, Vohs T, Tang J, Usimaki K, Olowolagba AM, Fritz DR, Luck RL, Werner T, Liu H. Near-infrared rhodol dyes bearing salicylaldehyde moieties for ratiometric pH sensing in live cells during mitophagy and under hypoxia conditions. J Mater Chem B 2023; 11:2852-2861. [PMID: 36808460 PMCID: PMC10171916 DOI: 10.1039/d2tb02791g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
We describe a simple but efficient approach to make fluorescent probes A and B based on rhodol dyes incorporated with salicyaldehyde moiety for monitoring pH changes in mitochondria under oxidative stresses and hypoxia conditions, and for tracking mitophagy processes. Probes A and B possess pKa values (pKa ≈ 6.41 and 6.83 respectively) near physiological pH and exhibit decent mitochondria-targeted capabilities, low cytotoxicity, and useful ratiometric and reversible pH responses, which make the probes appropriate for monitoring pH fluctuations of mitochondria in living cells with built-in calibration feature for quantitative analysis. The probes have been effectively useful for the ratiometric determination of pH variations of mitochondria under the stimuli of carbonyl cyanide-4(trifluoromethoxy)phenylhydrazone (FCCP), hydrogen peroxide (H2O2), and N-acetyl cysteine (NAC), and during mitophagy triggered by cell nutrient deprivation, and under hypoxia conditions with cobalt chloride (CoCl2) treatment in living cells. In addition, probe A was efficient in visualizing pH changes in the larvae of fruit flies.
Collapse
Affiliation(s)
- Sushil K Dwivedi
- Department of Chemistry, and Research Health Institute, Michigan Technological University, Houghton, MI 49931, USA.
| | - Dilka Liyana Arachchige
- Department of Chemistry, and Research Health Institute, Michigan Technological University, Houghton, MI 49931, USA.
| | - Tara Vohs
- Department of Chemistry, and Research Health Institute, Michigan Technological University, Houghton, MI 49931, USA.
| | - Jiani Tang
- High School, Houghton Portage Township Schools, Houghton, MI 49931, USA
| | - Kyle Usimaki
- Department of Chemistry, and Research Health Institute, Michigan Technological University, Houghton, MI 49931, USA.
| | - Adenike Mary Olowolagba
- Department of Chemistry, and Research Health Institute, Michigan Technological University, Houghton, MI 49931, USA.
| | - Delaney Raine Fritz
- Department of Biological Sciences, Michigan Technological University, Houghton, MI 49931, USA.
| | - Rudy L Luck
- Department of Chemistry, and Research Health Institute, Michigan Technological University, Houghton, MI 49931, USA.
| | - Thomas Werner
- Department of Biological Sciences, Michigan Technological University, Houghton, MI 49931, USA.
| | - Haiying Liu
- Department of Chemistry, and Research Health Institute, Michigan Technological University, Houghton, MI 49931, USA.
| |
Collapse
|
3
|
Murray JH, Burgio AL, Beretta M, Hargett SR, Harris TE, Olzomer E, Grams RJ, Garcia CJ, Li C, Salamoun JM, Hoehn KL, Santos WL. Oxadiazolopyridine Derivatives as Efficacious Mitochondrial Uncouplers in the Prevention of Diet-Induced Obesity. J Med Chem 2023; 66:3876-3895. [PMID: 36882080 PMCID: PMC10167758 DOI: 10.1021/acs.jmedchem.2c01573] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
Abstract
Small-molecule mitochondrial uncouplers are gaining recognition as potential therapeutics for metabolic diseases such as obesity, diabetes, and nonalcoholic steatohepatitis (NASH). Specifically, heterocycles derived from BAM15, a potent and mitochondria-selective uncoupler, have yielded promising preclinical candidates that are efficacious in animal models of obesity and NASH. In this study, we report the structure-activity relationship studies of 6-amino-[1,2,5]oxadiazolo[3,4-b]pyridin-5-ol derivatives. Using oxygen consumption rate as a readout of mitochondrial uncoupling, we established 5-hydroxyoxadiazolopyridines as mild uncouplers. In particular, SHM115, which contains a pentafluoro aniline, had an EC50 value of 17 μM and exhibited 75% oral bioavailability. SHM115 treatment increased the energy expenditure and lowered the body fat mass in two diet-induced obesity mouse models, including an obesity prevention model and an obesity reversal model. Taken together, our findings demonstrate the therapeutic potential of mild mitochondrial uncouplers for the prevention of diet-induced obesity.
Collapse
Affiliation(s)
- Jacob H Murray
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Ariel L Burgio
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Martina Beretta
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, New South Wales 2033, Australia
| | - Stefan R Hargett
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Thurl E Harris
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Ellen Olzomer
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, New South Wales 2033, Australia
| | - R Justin Grams
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Christopher J Garcia
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Catherine Li
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, New South Wales 2033, Australia
| | - Joseph M Salamoun
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Kyle L Hoehn
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, New South Wales 2033, Australia
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Webster L Santos
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| |
Collapse
|
4
|
Hannemann J, Böger R. Dysregulation of the Nitric Oxide/Dimethylarginine Pathway in Hypoxic Pulmonary Vasoconstriction—Molecular Mechanisms and Clinical Significance. Front Med (Lausanne) 2022; 9:835481. [PMID: 35252268 PMCID: PMC8891573 DOI: 10.3389/fmed.2022.835481] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 01/27/2022] [Indexed: 12/21/2022] Open
Abstract
The pulmonary circulation responds to hypoxia with vasoconstriction, a mechanism that helps to adapt to short-lived hypoxic episodes. When sustained, hypoxic pulmonary vasoconstriction (HPV) may become deleterious, causing right ventricular hypertrophy and failure, and contributing to morbidity and mortality in the late stages of several chronic pulmonary diseases. Nitric oxide (NO) is an important endothelial vasodilator. Its release is regulated, amongst other mechanisms, by the presence of endogenous inhibitors like asymmetric dimethylarginine (ADMA). Evidence has accumulated in recent years that elevated ADMA may be implicated in the pathogenesis of HPV and in its clinical sequelae, like pulmonary arterial hypertension (PAH). PAH is one phenotypic trait in experimental models with disrupted ADMA metabolism. In high altitude, elevation of ADMA occurs during long-term exposure to chronic or chronic intermittent hypobaric hypoxia; ADMA is significantly associated with high altitude pulmonary hypertension. High ADMA concentration was also reported in patients with chronic obstructive lung disease, obstructive sleep apnoea syndrome, and overlap syndrome, suggesting a pathophysiological role for ADMA-mediated impairment of endothelium-dependent, NO-mediated pulmonary vasodilation in these clinically relevant conditions. Improved understanding of the molecular (dys-)regulation of pathways controlling ADMA concentration may help to dissect the pathophysiology and find novel therapeutic options for these diseases.
Collapse
Affiliation(s)
- Juliane Hannemann
- Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Institute DECIPHER, German-Chilean Institute for Research on Pulmonary Hypoxia and its Health Sequelae, Hamburg, Germany
| | - Rainer Böger
- Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Institute DECIPHER, German-Chilean Institute for Research on Pulmonary Hypoxia and its Health Sequelae, Hamburg, Germany
- *Correspondence: Rainer Böger
| |
Collapse
|
5
|
Bai Q, Yang C, Yang M, Pei Z, Zhou X, Liu J, Ji H, Li G, Wu M, Qin Y, Wang Q, Wu L. pH-Dominated Selective Imaging of Lipid Droplets and Mitochondria via a Polarity-Reversible Ratiometric Fluorescent Probe. Anal Chem 2022; 94:2901-2911. [DOI: 10.1021/acs.analchem.1c04806] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Qingqing Bai
- Innovative Institute of Chinese Medicine and Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, P. R. China
| | - Chaojie Yang
- School of Public Health, Nantong University, Nantong 226019, P. R. China
| | - Majun Yang
- School of Public Health, Nantong University, Nantong 226019, P. R. China
| | - Zhaoqing Pei
- Innovative Institute of Chinese Medicine and Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, P. R. China
| | - Xiaobo Zhou
- School of Public Health, Nantong University, Nantong 226019, P. R. China
| | - Jinxia Liu
- School of Public Health, Nantong University, Nantong 226019, P. R. China
| | - Haiwei Ji
- School of Public Health, Nantong University, Nantong 226019, P. R. China
| | - Guo Li
- School of Public Health, Nantong University, Nantong 226019, P. R. China
| | - Mingmin Wu
- School of Public Health, Nantong University, Nantong 226019, P. R. China
| | - Yuling Qin
- School of Public Health, Nantong University, Nantong 226019, P. R. China
| | - Qi Wang
- Innovative Institute of Chinese Medicine and Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, P. R. China
- School of Public Health, Nantong University, Nantong 226019, P. R. China
| | - Li Wu
- School of Public Health, Nantong University, Nantong 226019, P. R. China
| |
Collapse
|
6
|
Urra FA, Fuentes-Retamal S, Palominos C, Rodríguez-Lucart YA, López-Torres C, Araya-Maturana R. Extracellular Matrix Signals as Drivers of Mitochondrial Bioenergetics and Metabolic Plasticity of Cancer Cells During Metastasis. Front Cell Dev Biol 2021; 9:751301. [PMID: 34733852 PMCID: PMC8558415 DOI: 10.3389/fcell.2021.751301] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 09/28/2021] [Indexed: 12/16/2022] Open
Abstract
The role of metabolism in tumor growth and chemoresistance has received considerable attention, however, the contribution of mitochondrial bioenergetics in migration, invasion, and metastasis is recently being understood. Migrating cancer cells adapt their energy needs to fluctuating changes in the microenvironment, exhibiting high metabolic plasticity. This occurs due to dynamic changes in the contributions of metabolic pathways to promote localized ATP production in lamellipodia and control signaling mediated by mitochondrial reactive oxygen species. Recent evidence has shown that metabolic shifts toward a mitochondrial metabolism based on the reductive carboxylation, glutaminolysis, and phosphocreatine-creatine kinase pathways promote resistance to anoikis, migration, and invasion in cancer cells. The PGC1a-driven metabolic adaptations with increased electron transport chain activity and superoxide levels are essential for metastasis in several cancer models. Notably, these metabolic changes can be determined by the composition and density of the extracellular matrix (ECM). ECM stiffness, integrins, and small Rho GTPases promote mitochondrial fragmentation, mitochondrial localization in focal adhesion complexes, and metabolic plasticity, supporting enhanced migration and metastasis. Here, we discuss the role of ECM in regulating mitochondrial metabolism during migration and metastasis, highlighting the therapeutic potential of compounds affecting mitochondrial function and selectively block cancer cell migration.
Collapse
Affiliation(s)
- Félix A Urra
- Laboratorio de Plasticidad Metabólica y Bioenergética, Programa de Farmacología Molecular y Clínica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Network for Snake Venom Research and Drug Discovery, Santiago, Chile
| | - Sebastián Fuentes-Retamal
- Laboratorio de Plasticidad Metabólica y Bioenergética, Programa de Farmacología Molecular y Clínica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Network for Snake Venom Research and Drug Discovery, Santiago, Chile
| | - Charlotte Palominos
- Laboratorio de Plasticidad Metabólica y Bioenergética, Programa de Farmacología Molecular y Clínica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Network for Snake Venom Research and Drug Discovery, Santiago, Chile
| | - Yarcely A Rodríguez-Lucart
- Network for Snake Venom Research and Drug Discovery, Santiago, Chile.,Instituto de Química de Recursos Naturales, Universidad de Talca, Talca, Chile
| | - Camila López-Torres
- Laboratorio de Plasticidad Metabólica y Bioenergética, Programa de Farmacología Molecular y Clínica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Network for Snake Venom Research and Drug Discovery, Santiago, Chile
| | - Ramiro Araya-Maturana
- Network for Snake Venom Research and Drug Discovery, Santiago, Chile.,Instituto de Química de Recursos Naturales, Universidad de Talca, Talca, Chile
| |
Collapse
|
7
|
Ahmad W, Ebert PR. Suppression of a core metabolic enzyme dihydrolipoamide dehydrogenase ( dld) protects against amyloid beta toxicity in C. elegans model of Alzheimer's disease. Genes Dis 2021; 8:849-866. [PMID: 34522713 PMCID: PMC8427249 DOI: 10.1016/j.gendis.2020.08.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/24/2020] [Accepted: 08/14/2020] [Indexed: 01/24/2023] Open
Abstract
A decrease in energy metabolism is associated with Alzheimer's disease (AD), but it is not known whether the observed decrease exacerbates or protects against the disease. The importance of energy metabolism in AD is reinforced by the observation that variants of dihydrolipoamide dehydrogenase (DLD), is genetically linked to late-onset AD. To determine whether DLD is a suitable therapeutic target, we suppressed the dld-1 gene in Caenorhabditis elegans that express human Aβ peptide in either muscles or neurons. Suppression of the dld-1 gene resulted in significant restoration of vitality and function that had been degraded by Aβ pathology. This included protection of neurons and muscles cells. The observed decrease in proteotoxicity was associated with a decrease in the formation of toxic oligomers rather than a decrease in the abundance of the Aβ peptide. The mitochondrial uncoupler, carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (FCCP), which like dld-1 gene expression inhibits ATP synthesis, had no significant effect on Aβ toxicity. Proteomics data analysis revealed that beneficial effects after dld-1 suppression could be due to change in energy metabolism and activation of the pathways associated with proteasomal degradation, improved cell signaling and longevity. Thus, some features unique to dld-1 gene suppression are responsible for the therapeutic benefit. By direct genetic intervention, we have shown that acute inhibition of dld-1 gene function may be therapeutically beneficial. This result supports the hypothesis that lowering energy metabolism protects against Aβ pathogenicity and that DLD warrants further investigation as a therapeutic target.
Collapse
Affiliation(s)
- Waqar Ahmad
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Paul R. Ebert
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| |
Collapse
|
8
|
Iturriaga R, Alcayaga J, Chapleau MW, Somers VK. Carotid body chemoreceptors: physiology, pathology, and implications for health and disease. Physiol Rev 2021; 101:1177-1235. [PMID: 33570461 PMCID: PMC8526340 DOI: 10.1152/physrev.00039.2019] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The carotid body (CB) is the main peripheral chemoreceptor for arterial respiratory gases O2 and CO2 and pH, eliciting reflex ventilatory, cardiovascular, and humoral responses to maintain homeostasis. This review examines the fundamental biology underlying CB chemoreceptor function, its contribution to integrated physiological responses, and its role in maintaining health and potentiating disease. Emphasis is placed on 1) transduction mechanisms in chemoreceptor (type I) cells, highlighting the role played by the hypoxic inhibition of O2-dependent K+ channels and mitochondrial oxidative metabolism, and their modification by intracellular molecules and other ion channels; 2) synaptic mechanisms linking type I cells and petrosal nerve terminals, focusing on the role played by the main proposed transmitters and modulatory gases, and the participation of glial cells in regulation of the chemosensory process; 3) integrated reflex responses to CB activation, emphasizing that the responses differ dramatically depending on the nature of the physiological, pathological, or environmental challenges, and the interactions of the chemoreceptor reflex with other reflexes in optimizing oxygen delivery to the tissues; and 4) the contribution of enhanced CB chemosensory discharge to autonomic and cardiorespiratory pathophysiology in obstructive sleep apnea, congestive heart failure, resistant hypertension, and metabolic diseases and how modulation of enhanced CB reactivity in disease conditions may attenuate pathophysiology.
Collapse
Affiliation(s)
- Rodrigo Iturriaga
- Laboratorio de Neurobiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile, and Centro de Excelencia en Biomedicina de Magallanes, Universidad de Magallanes, Punta Arenas, Chile
| | - Julio Alcayaga
- Laboratorio de Fisiología Celular, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Mark W Chapleau
- Department of Internal Medicine, University of Iowa and Department of Veterans Affairs Medical Center, Iowa City, Iowa
| | - Virend K Somers
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota
| |
Collapse
|
9
|
de Souza-Guerreiro TC, Asally M. Seeking Insights into Aging Through Yeast Mitochondrial Electrophysiology. Bioelectricity 2021; 3:111-115. [PMID: 34476385 DOI: 10.1089/bioe.2021.0011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
During aging, mitochondrial membrane potential, a key indicator for bioenergetics of cells, depolarizes in a wide range of species-from yeasts, plants to animals. In humans, the decline of mitochondrial activities can impact the high-energy-consuming organs, such as the brain and heart, and increase the risks of age-linked diseases. Intriguingly, a mild depolarization of mitochondria has lifespan-extending effects, suggesting an important role played by bioelectricity during aging. However, the underpinning biophysical mechanism is not very well understood due in part to the difficulties associated with a multiscale process. Budding yeast Saccharomyces cerevisiae could provide a model system to bridge this knowledge gap and provide insights into aging. In this perspective, we overview recent studies on the yeast mitochondrial membrane electrophysiology and aging and call for more electrochemical and biophysical studies on aging.
Collapse
Affiliation(s)
- Tailise Carolina de Souza-Guerreiro
- Warwick Integrative Synthetic Biology Centre, University of Warwick, Coventry, United Kingdom.,School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Munehiro Asally
- Warwick Integrative Synthetic Biology Centre, University of Warwick, Coventry, United Kingdom.,School of Life Sciences, University of Warwick, Coventry, United Kingdom.,Bio-Electrical Engineering Innovation Hub, University of Warwick, Coventry, United Kingdom
| |
Collapse
|
10
|
Chen SY, Beretta M, Alexopoulos SJ, Shah DP, Olzomer EM, Hargett SR, Childress ES, Salamoun JM, Aleksovska I, Roseblade A, Cranfield C, Rawling T, Quinlan KGR, Morris MJ, Tucker SP, Santos WL, Hoehn KL. Mitochondrial uncoupler SHC517 reverses obesity in mice without affecting food intake. Metabolism 2021; 117:154724. [PMID: 33548253 DOI: 10.1016/j.metabol.2021.154724] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/27/2021] [Accepted: 02/01/2021] [Indexed: 12/13/2022]
Abstract
AIMS Mitochondrial uncouplers decrease caloric efficiency and have potential therapeutic benefits for the treatment of obesity and related metabolic disorders. Herein we investigate the metabolic and physiologic effects of a recently identified small molecule mitochondrial uncoupler named SHC517 in a mouse model of diet-induced obesity. METHODS SHC517 was administered as an admixture in food. The effect of SHC517 on in vivo energy expenditure and respiratory quotient was determined by indirect calorimetry. A dose-finding obesity prevention study was performed by starting SHC517 treatment concomitant with high fat diet for a period of 12 days. An obesity reversal study was performed by feeding mice western diet for 4 weeks prior to SHC517 treatment for 7 weeks. Biochemical assays were used to determine changes in glucose, insulin, triglycerides, and cholesterol. SHC517 concentrations were determined by mass spectrometry. RESULTS SHC517 increased lipid oxidation without affecting body temperature. SHC517 prevented diet-induced obesity when administered at 0.05% and 0.1% w/w in high fat diet and reversed established obesity when tested at the 0.05% dose. In the obesity reversal model, SHC517 restored adiposity to levels similar to chow-fed control mice without affecting food intake or lean body mass. SHC517 improved glucose tolerance and fasting glucose levels when administered in both the obesity prevention and obesity reversal modes. CONCLUSIONS SHC517 is a mitochondrial uncoupler with potent anti-obesity and insulin sensitizing effects in mice. SHC517 reversed obesity without altering food intake or compromising lean mass, effects that are highly sought-after in anti-obesity therapeutics.
Collapse
Affiliation(s)
- Sing-Young Chen
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Martina Beretta
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Stephanie J Alexopoulos
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Divya P Shah
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Ellen M Olzomer
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Stefan R Hargett
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Elizabeth S Childress
- Department of Chemistry and Virginia Tech Centre for Drug Discovery, Virginia Tech, Blacksburg, VA 24061, USA
| | - Joseph M Salamoun
- Department of Chemistry and Virginia Tech Centre for Drug Discovery, Virginia Tech, Blacksburg, VA 24061, USA
| | - Isabella Aleksovska
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Ariane Roseblade
- School of Mathematical and Physical Sciences, University of Technology, Sydney, NSW 2007, Australia
| | - Charles Cranfield
- School of Life Sciences, University of Technology, Sydney, NSW 2007, Australia
| | - Tristan Rawling
- School of Mathematical and Physical Sciences, University of Technology, Sydney, NSW 2007, Australia
| | - Kate G R Quinlan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Margaret J Morris
- School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Simon P Tucker
- Continuum Biosciences Pty Ltd., Sydney, NSW, 2035, Australia
| | - Webster L Santos
- Department of Chemistry and Virginia Tech Centre for Drug Discovery, Virginia Tech, Blacksburg, VA 24061, USA; Continuum Biosciences Pty Ltd., Sydney, NSW, 2035, Australia.
| | - Kyle L Hoehn
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia; Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA.; Continuum Biosciences Pty Ltd., Sydney, NSW, 2035, Australia.
| |
Collapse
|
11
|
Katram N, Garlapati PK, Yadavalli C, Methal RE, Rajappa SBG, Raghavan AK. Aegle marmelos extract rich in marmelosin exacted ameliorative effect against chromium-induced oxidative stress and apoptosis through regulation of Gadd45 in HepG2 cell line. J Food Biochem 2021; 45:e13704. [PMID: 33719131 DOI: 10.1111/jfbc.13704] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/03/2021] [Accepted: 03/02/2021] [Indexed: 11/28/2022]
Abstract
Hexavalent chromium [Cr (VI)] is highly toxic compared to other valence states of chromium. In the process of metabolic reduction, Cr (VI) converts to trivalent chromium. Aegle marmelos (Bael), a sacred plant of India and its fruits are being consumed as traditional formulations against various diseases such as ulcer, gastric mucosal damage, inflammations, febrile delirium, acute bronchitis, anxiety, etc. The present study assessed the protective effects of marmelosin (MAR) from Aegle marmelos against K2 Cr2 O7 -induced toxic effects in HepG2 cell line through its antiapoptotic mechanism. Results of the study revealed that pretreatment of MAR ameliorated cell viability, mitochondrial damage, and DNA damage induced by K2 Cr2 O7 in HepG2 cell line as evidenced by cell morphology, MTT, LDH, and MMP assays. Pretreatment of MAR attenuated K2 Cr2 O7 -induced oxidative stress by downregulating intracellular ROS and RNS. Further, pretreatment of MAR significantly downregulated K2 Cr2 O7 -induced apoptotic markers, such as Bax, Caspase 3, and Gadd45. Our results suggested that application of marmelosin could be beneficial in ameliorating chromium-induced apoptotic cell death by suppressing oxidative stress and regulating excessive DNA damage. PRACTICAL APPLICATIONS: The study focused on protective mechanism of marmelosin from Aegle marmelos against chromium-induced oxidative stress for the first time. In this research, we reported that marmelosin effectively ameliorated K2 Cr2 O7 -induced morphological changes such as oxidative stress and apoptotic cell death by regulating Gadd45, Bcl-2, Bax, and Caspase 3 gene expressions, and inhibition of intracellular ROS and RNS. The study provides a better understanding of the pharmacological mechanisms of Aegle marmelos and its bioactive compound, that is, marmelosin in the management of intoxication of heavy metals associated with excessive DNA damage.
Collapse
Affiliation(s)
- Navya Katram
- Defence Food Research Laboratory (DFRL), Defence Research and Defence Organization (DRDO), Mysore, India
| | - Phani Kumar Garlapati
- Defence Food Research Laboratory (DFRL), Defence Research and Defence Organization (DRDO), Mysore, India
| | | | - Ramya Edavalath Methal
- Defence Food Research Laboratory (DFRL), Defence Research and Defence Organization (DRDO), Mysore, India
| | | | | |
Collapse
|
12
|
Therapeutic potential of mitochondrial uncouplers for the treatment of metabolic associated fatty liver disease and NASH. Mol Metab 2021; 46:101178. [PMID: 33545391 PMCID: PMC8085597 DOI: 10.1016/j.molmet.2021.101178] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 01/18/2021] [Accepted: 01/28/2021] [Indexed: 12/13/2022] Open
Abstract
Background Mitochondrial uncouplers shuttle protons across the inner mitochondrial membrane via a pathway that is independent of adenosine triphosphate (ATP) synthase, thereby uncoupling nutrient oxidation from ATP production and dissipating the proton gradient as heat. While initial toxicity concerns hindered their therapeutic development in the early 1930s, there has been increased interest in exploring the therapeutic potential of mitochondrial uncouplers for the treatment of metabolic diseases. Scope of review In this review, we cover recent advances in the mechanisms by which mitochondrial uncouplers regulate biological processes and disease, with a particular focus on metabolic associated fatty liver disease (MAFLD), nonalcoholic hepatosteatosis (NASH), insulin resistance, and type 2 diabetes (T2D). We also discuss the challenges that remain to be addressed before synthetic and natural mitochondrial uncouplers can successfully enter the clinic. Major conclusions Rodent and non-human primate studies suggest that a myriad of small molecule mitochondrial uncouplers can safely reverse MAFLD/NASH with a wide therapeutic index. Despite this, further characterization of the tissue- and cell-specific effects of mitochondrial uncouplers is needed. We propose targeting the dosing of mitochondrial uncouplers to specific tissues such as the liver and/or developing molecules with self-limiting properties to induce a subtle and sustained increase in mitochondrial inefficiency, thereby avoiding systemic toxicity concerns.
Collapse
|
13
|
Saarti M, Almukhtar H, Smith PA, Roberts RE. Effect of mitochondrial complex III inhibitors on the regulation of vascular tone in porcine coronary artery. Eur J Pharmacol 2021; 896:173917. [PMID: 33529727 DOI: 10.1016/j.ejphar.2021.173917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 01/06/2021] [Accepted: 01/26/2021] [Indexed: 11/30/2022]
Abstract
In order to gain insight into the regulation of vascular tone by mitochondria, the effects of mitochondrial complex III inhibitors on contractile responses in porcine isolated coronary arteries were investigated. Segments of porcine coronary arteries were set up for isometric tension recording and concentration response curves to contractile agents were carried out in the absence or presence of the complex III inhibitors antimycin A or myxothiazol. Activity of AMP kinase was determined by measuring changes in phosphorylation of AMP kinase at Thr172. Pre-incubation with 10 μM antimycin A (Qi site inhibitor), or myxothiazol (Qo site inhibitor) led to inhibition of the contraction to the thromboxane receptor agonist U46619. Similar effects were seen on contractile responses to extracellular calcium, and the L-type calcium channel opener BAY K 8644, suggesting that both antimycin A and myxothiazol inhibit calcium-dependent contractions. The inhibitory effect of antimycin A was still seen in the absence of extracellular calcium, indicating an additional effect on a calcium independent pathway. The AMP kinase inhibitor dorsomorphin (10 μM) prevented the inhibitory of antimycin A but not myxothiazol. Furthermore, antimycin A increased the phosphorylation of AMP kinase, indicating an increase in activity, suggesting that antimycin A also acts through this pathway. These data indicate that inhibition of complex III attenuates contractile responses through inhibition of calcium influx. However, inhibition of the Qi site can also inhibit the contractile response through activation of AMP kinase.
Collapse
Affiliation(s)
- Mohammed Saarti
- School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Hani Almukhtar
- School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Paul A Smith
- School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Richard E Roberts
- School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, UK.
| |
Collapse
|
14
|
Role of IP3 Receptors in Shaping the Carotid Chemoreceptor Response to Hypoxia But Not to Hypercapnia in the Rat Carotid Body: An Evidence Review. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021. [PMID: 32767266 DOI: 10.1007/5584_2020_561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
This article addresses the disparity in the transduction pathways for hypoxic and hypercapnic stimuli in carotid body glomus cells. We investigated and reviewed the experimental evidence showing that the response to hypoxia, but not to hypercapnia, is mediated by 1,4,5-inositol triphosphate receptors (IP3R/s) regulating the intracellular calcium content [Ca2+]c in glomus cells. The rationale was based on the past observations that inhibition of oxidative phosphorylation leads to the explicit inhibition of the hypoxic chemoreflex. [Ca2+]c changes were measured using cellular Ca2+-sensitive fluorescent probes, and carotid sinus nerve (CSN) sensory discharge was recorded with bipolar electrodes in in vitro perfused-superfused rat carotid body preparations. The cell-permeant, 2-amino-ethoxy-diphenyl-borate (2-APB; 100 μM) and curcumin (50 μM) were used as the inhibitors of IP3R/s. These agents suppressed the [Ca2+]c, and CSN discharge increases in hypoxia but not in hypercapnia, leading to the conclusion that only the hypoxic effects were mediated via modulation of IP3R/s. The ATP-induced Ca2+ release from intracellular stores in a Ca2+-free medium was blocked with 2-APB, supporting this conclusion.
Collapse
|
15
|
Axelrod CL, King WT, Davuluri G, Noland RC, Hall J, Hull M, Dantas WS, Zunica ERM, Alexopoulos SJ, Hoehn KL, Langohr I, Stadler K, Doyle H, Schmidt E, Nieuwoudt S, Fitzgerald K, Pergola K, Fujioka H, Mey JT, Fealy C, Mulya A, Beyl R, Hoppel CL, Kirwan JP. BAM15-mediated mitochondrial uncoupling protects against obesity and improves glycemic control. EMBO Mol Med 2020; 12:e12088. [PMID: 32519812 PMCID: PMC7338798 DOI: 10.15252/emmm.202012088] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 05/15/2020] [Accepted: 05/15/2020] [Indexed: 11/09/2022] Open
Abstract
Obesity is a leading cause of preventable death worldwide. Despite this, current strategies for the treatment of obesity remain ineffective at achieving long-term weight control. This is due, in part, to difficulties in identifying tolerable and efficacious small molecules or biologics capable of regulating systemic nutrient homeostasis. Here, we demonstrate that BAM15, a mitochondrially targeted small molecule protonophore, stimulates energy expenditure and glucose and lipid metabolism to protect against diet-induced obesity. Exposure to BAM15 in vitro enhanced mitochondrial respiratory kinetics, improved insulin action, and stimulated nutrient uptake by sustained activation of AMPK. C57BL/6J mice treated with BAM15 were resistant to weight gain. Furthermore, BAM15-treated mice exhibited improved body composition and glycemic control independent of weight loss, effects attributable to drug targeting of lipid-rich tissues. We provide the first phenotypic characterization and demonstration of pre-clinical efficacy for BAM15 as a pharmacological approach for the treatment of obesity and related diseases.
Collapse
Affiliation(s)
- Christopher L Axelrod
- Integrated Physiology and Molecular Medicine LaboratoryPennington Biomedical Research CenterBaton RougeLAUSA
- Department of Translational ServicesPennington Biomedical Research CenterBaton RougeLAUSA
- Department of Inflammation and ImmunityLerner Research InstituteCleveland ClinicClevelandOHUSA
| | - William T King
- Integrated Physiology and Molecular Medicine LaboratoryPennington Biomedical Research CenterBaton RougeLAUSA
- Department of Translational ServicesPennington Biomedical Research CenterBaton RougeLAUSA
| | - Gangarao Davuluri
- Integrated Physiology and Molecular Medicine LaboratoryPennington Biomedical Research CenterBaton RougeLAUSA
- Sarcopenia and Malnutrition LaboratoryPennington Biomedical Research CenterBaton RougeLAUSA
| | - Robert C Noland
- Skeletal Muscle Metabolism LaboratoryPennington Biomedical Research CenterBaton RougeLAUSA
| | - Jacob Hall
- Integrated Physiology and Molecular Medicine LaboratoryPennington Biomedical Research CenterBaton RougeLAUSA
- Department of Translational ServicesPennington Biomedical Research CenterBaton RougeLAUSA
| | - Michaela Hull
- Department of Inflammation and ImmunityLerner Research InstituteCleveland ClinicClevelandOHUSA
| | - Wagner S Dantas
- Integrated Physiology and Molecular Medicine LaboratoryPennington Biomedical Research CenterBaton RougeLAUSA
| | - Elizabeth RM Zunica
- Integrated Physiology and Molecular Medicine LaboratoryPennington Biomedical Research CenterBaton RougeLAUSA
- Department of NutritionCase Western Reserve UniversityClevelandOHUSA
| | - Stephanie J Alexopoulos
- School of Biotechnology and Biomolecular SciencesUniversity of New South WalesSydneyNSWAustralia
| | - Kyle L Hoehn
- School of Biotechnology and Biomolecular SciencesUniversity of New South WalesSydneyNSWAustralia
| | - Ingeborg Langohr
- Department of Pathobiological SciencesLouisiana State UniversityBaton RougeLAUSA
| | - Krisztian Stadler
- Oxidative Stress and Disease LaboratoryPennington Biomedical Research CenterBaton RougeLAUSA
| | - Haylee Doyle
- Oxidative Stress and Disease LaboratoryPennington Biomedical Research CenterBaton RougeLAUSA
| | - Eva Schmidt
- Oxidative Stress and Disease LaboratoryPennington Biomedical Research CenterBaton RougeLAUSA
| | - Stephan Nieuwoudt
- Department of Inflammation and ImmunityLerner Research InstituteCleveland ClinicClevelandOHUSA
| | - Kelly Fitzgerald
- Department of Inflammation and ImmunityLerner Research InstituteCleveland ClinicClevelandOHUSA
| | - Kathryn Pergola
- Integrated Physiology and Molecular Medicine LaboratoryPennington Biomedical Research CenterBaton RougeLAUSA
- Department of Translational ServicesPennington Biomedical Research CenterBaton RougeLAUSA
| | - Hisashi Fujioka
- Cryo‐Electron Microscopy CoreCase Western Reserve UniversityClevelandOHUSA
| | - Jacob T Mey
- Integrated Physiology and Molecular Medicine LaboratoryPennington Biomedical Research CenterBaton RougeLAUSA
- Department of Inflammation and ImmunityLerner Research InstituteCleveland ClinicClevelandOHUSA
| | - Ciaran Fealy
- Department of Inflammation and ImmunityLerner Research InstituteCleveland ClinicClevelandOHUSA
| | - Anny Mulya
- Department of Inflammation and ImmunityLerner Research InstituteCleveland ClinicClevelandOHUSA
| | - Robbie Beyl
- Department of BiostatisticsPennington Biomedical Research CenterBaton RougeLAUSA
| | - Charles L Hoppel
- Integrated Physiology and Molecular Medicine LaboratoryPennington Biomedical Research CenterBaton RougeLAUSA
- Department of PharmacologyCase Western Reserve UniversityClevelandOHUSA
| | - John P Kirwan
- Integrated Physiology and Molecular Medicine LaboratoryPennington Biomedical Research CenterBaton RougeLAUSA
- Department of Inflammation and ImmunityLerner Research InstituteCleveland ClinicClevelandOHUSA
- Department of NutritionCase Western Reserve UniversityClevelandOHUSA
| |
Collapse
|
16
|
Salamoun JM, Garcia CJ, Hargett SR, Murray JH, Chen SY, Beretta M, Alexopoulos SJ, Shah DP, Olzomer EM, Tucker SP, Hoehn KL, Santos WL. 6-Amino[1,2,5]oxadiazolo[3,4- b]pyrazin-5-ol Derivatives as Efficacious Mitochondrial Uncouplers in STAM Mouse Model of Nonalcoholic Steatohepatitis. J Med Chem 2020; 63:6203-6224. [PMID: 32392051 PMCID: PMC11042500 DOI: 10.1021/acs.jmedchem.0c00542] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Small molecule mitochondrial uncouplers have recently garnered great interest for their potential in treating nonalcoholic steatohepatitis (NASH). In this study, we report the structure-activity relationship profiling of a 6-amino[1,2,5]oxadiazolo[3,4-b]pyrazin-5-ol core, which utilizes the hydroxy moiety as the proton transporter across the mitochondrial inner membrane. We demonstrate that a wide array of substituents is tolerated with this novel scaffold that increased cellular metabolic rates in vitro using changes in oxygen consumption rate as a readout. In particular, compound SHS4121705 (12i) displayed an EC50 of 4.3 μM in L6 myoblast cells and excellent oral bioavailability and liver exposure in mice. In the STAM mouse model of NASH, administration of 12i at 25 mg kg-1 day-1 lowered liver triglyceride levels and improved liver markers such as alanine aminotransferase, NAFLD activity score, and fibrosis. Importantly, no changes in body temperature or food intake were observed. As potential treatment of NASH, mitochondrial uncouplers show promise for future development.
Collapse
Affiliation(s)
- Joseph M Salamoun
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Christopher J Garcia
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Stefan R Hargett
- Departments of Pharmacology and Medicine, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Jacob H Murray
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Sing-Young Chen
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - Martina Beretta
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - Stephanie J Alexopoulos
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - Divya P Shah
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - Ellen M Olzomer
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - Simon P Tucker
- Continuum Biosciences, Pty Ltd., Sydney 2035, Australia
- Continuum Biosciences Inc., Boston, Massachusetts 02116, United States
| | - Kyle L Hoehn
- Departments of Pharmacology and Medicine, University of Virginia, Charlottesville, Virginia 22908, United States
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - Webster L Santos
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| |
Collapse
|
17
|
Donoso-Bustamante V, Borrego EA, Schiaffino-Bustamante Y, Gutiérrez DA, Millas-Vargas JP, Fuentes-Retamal S, Correa P, Carrillo I, Aguilera RJ, Miranda D, Chávez-Báez I, Pulgar R, Urra FA, Varela-Ramírez A, Araya-Maturana R. An acylhydroquinone derivative produces OXPHOS uncoupling and sensitization to BH3 mimetic ABT-199 (Venetoclax) in human promyelocytic leukemia cells. Bioorg Chem 2020; 100:103935. [PMID: 32454391 DOI: 10.1016/j.bioorg.2020.103935] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 05/02/2020] [Accepted: 05/11/2020] [Indexed: 12/16/2022]
Abstract
Since cancer cells have different mitochondrial bioenergetic requirements than non-cancerous cells, therapeutic inhibition of its mitochondrial functionality continues to be an important target for anticancer drug discovery. In this study, a series of acylhydroquinones with different acyl-chain length, and their chlorinated derivatives, in the aromatic ring, synthesized by Fries rearrangement under microwave irradiation, were evaluated for their anticancer activity in two leukemia cell lines. Findings from the primary and secondary screening of the 18 acylhydroquinones, tested at 5 µM on acute promyelocytic leukemia HL-60 and acute lymphoblastic leukemia CEM cells lines, identified an acylchlorohydroquinone (12) with a highly selective anti-proliferative effect toward HL-60 cells. This compound induced S-phase arrest in the cell cycle progression of HL-60 cells with insignificant toxicity on leukemic CEM cells and non-cancerous Hs27 cells. In HL-60 leukemic cells, 12 triggered increased mitochondrial NADH oxidation, increased respiration in presence of oligomycin (state 4o), mitochondrial depolarization, and ROS production, suggesting an uncoupling of OXPHOS. This provoked a metabolic adaptation dependent on AMPK/ACC/autophagy axis, having the mitochondrial β-oxidation a pro-survival role since the combination of 12 and etomoxir, a carnitine palmitoyl-transferase (CPT) inhibitor promoted extensive HL-60 cell death. Finally, 12-induced metabolic stress sensitized to HL-60 cells to cell death by the FDA-approved anti-leukemic drug ABT-199, a BH3 mimetic. Therefore, our results suggest that acylchlorohydroquinone is a promising scaffold in anti-promyelocytic leukemia drug research.
Collapse
Affiliation(s)
- Viviana Donoso-Bustamante
- Instituto de Química de Recursos Naturales, Universidad de Talca, Chile; Programa de Investigación Asociativa en Cáncer Gástrico, Universidad de Talca, Chile
| | - Edgar A Borrego
- Border Biomedical Research Center, Department of Biological Sciences, The University of Texas at El Paso, USA
| | | | - Denisse A Gutiérrez
- Border Biomedical Research Center, Department of Biological Sciences, The University of Texas at El Paso, USA
| | - Juan Pablo Millas-Vargas
- Instituto de Química de Recursos Naturales, Universidad de Talca, Chile; Network for Snake Venom Research and Drug Discovery, Santiago, Chile
| | - Sebastián Fuentes-Retamal
- Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile; Programa de Investigación Asociativa en Cáncer Gástrico, Universidad de Talca, Chile; Network for Snake Venom Research and Drug Discovery, Santiago, Chile
| | - Pablo Correa
- Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile; Network for Snake Venom Research and Drug Discovery, Santiago, Chile
| | - Ileana Carrillo
- Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Renato J Aguilera
- Border Biomedical Research Center, Department of Biological Sciences, The University of Texas at El Paso, USA
| | - Dante Miranda
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
| | - Ignacio Chávez-Báez
- Network for Snake Venom Research and Drug Discovery, Santiago, Chile; Laboratorio de Genómica y Genética de Interacciones Biológicas, INTA-Universidad de Chile, Santiago, Chile
| | - Rodrigo Pulgar
- Network for Snake Venom Research and Drug Discovery, Santiago, Chile; Laboratorio de Genómica y Genética de Interacciones Biológicas, INTA-Universidad de Chile, Santiago, Chile
| | - Félix A Urra
- Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile; Network for Snake Venom Research and Drug Discovery, Santiago, Chile.
| | - Armando Varela-Ramírez
- Border Biomedical Research Center, Department of Biological Sciences, The University of Texas at El Paso, USA.
| | - Ramiro Araya-Maturana
- Instituto de Química de Recursos Naturales, Universidad de Talca, Chile; Network for Snake Venom Research and Drug Discovery, Santiago, Chile.
| |
Collapse
|
18
|
Anilinopyrazines as potential mitochondrial uncouplers. Bioorg Med Chem Lett 2020; 30:127057. [DOI: 10.1016/j.bmcl.2020.127057] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 02/16/2020] [Accepted: 02/20/2020] [Indexed: 12/18/2022]
|
19
|
Childress ES, Salamoun JM, Hargett SR, Alexopoulos SJ, Chen SY, Shah DP, Santiago-Rivera J, Garcia CJ, Dai Y, Tucker SP, Hoehn KL, Santos WL. [1,2,5]Oxadiazolo[3,4- b]pyrazine-5,6-diamine Derivatives as Mitochondrial Uncouplers for the Potential Treatment of Nonalcoholic Steatohepatitis. J Med Chem 2020; 63:2511-2526. [PMID: 32017849 DOI: 10.1021/acs.jmedchem.9b01440] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Small molecule mitochondrial uncouplers are emerging as a new class of molecules for the treatment of nonalcoholic steatohepatitis. We utilized BAM15, a potent protonophore that uncouples the mitochondria without depolarizing the plasma membrane, as a lead compound for structure-activity profiling. Using oxygen consumption rate as an assay for determining uncoupling activity, changes on the 5- and 6-position of the oxadiazolopyrazine core were introduced. Our studies suggest that unsymmetrical aniline derivatives bearing electron withdrawing groups are preferred compared to the symmetrical counterparts. In addition, alkyl substituents are not tolerated, and the N-H proton of the aniline ring is responsible for the protonophore activity. In particular, compound 10b had an EC50 value of 190 nM in L6 myoblast cells. In an in vivo model of NASH, 10b decreased liver triglyceride levels and showed improvement in fibrosis, inflammation, and plasma ALT. Taken together, our studies indicate that mitochondrial uncouplers have potential for the treatment of NASH.
Collapse
Affiliation(s)
- Elizabeth S Childress
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Joseph M Salamoun
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Stefan R Hargett
- Departments of Pharmacology and Medicine, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Stephanie J Alexopoulos
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - Sing-Young Chen
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - Divya P Shah
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - José Santiago-Rivera
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Christopher J Garcia
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Yumin Dai
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Simon P Tucker
- Continuum Biosciences, Pty Ltd., 2035 Sydney, Australia.,Continuum Biosciences Inc., Boston, Massachusetts 02116, United States
| | - Kyle L Hoehn
- Departments of Pharmacology and Medicine, University of Virginia, Charlottesville, Virginia 22908, United States.,School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - Webster L Santos
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| |
Collapse
|
20
|
Liu X, Wang L, Bing T, Zhang N, Dihua Shangguan. A Mitochondria-Targeted Ratiometric Fluorescent pH Probe. ACS APPLIED BIO MATERIALS 2019; 2:1368-1375. [DOI: 10.1021/acsabm.9b00061] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Xiangjun Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Linlin Wang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tao Bing
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Nan Zhang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dihua Shangguan
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
21
|
Prabhakar NR, Peng YJ, Nanduri J. Recent advances in understanding the physiology of hypoxic sensing by the carotid body. F1000Res 2018; 7. [PMID: 30631432 PMCID: PMC6284772 DOI: 10.12688/f1000research.16247.1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/29/2018] [Indexed: 01/05/2023] Open
Abstract
Hypoxia resulting from reduced oxygen (O
2) levels in the arterial blood is sensed by the carotid body (CB) and triggers reflex stimulation of breathing and blood pressure to maintain homeostasis. Studies in the past five years provided novel insights into the roles of heme oxygenase-2 (HO-2), a carbon monoxide (CO)-producing enzyme, and NADH dehydrogenase Fe-S protein 2, a subunit of the mitochondrial complex I, in hypoxic sensing by the CB. HO-2 is expressed in type I cells, the primary O2-sensing cells of the CB, and binds to O
2 with low affinity. O
2-dependent CO production from HO-2 mediates hypoxic response of the CB by regulating H
2S generation. Mice lacking NDUFS2 show that complex I-generated reactive oxygen species acting on K
+ channels confer type I cell response to hypoxia. Whether these signaling pathways operate synergistically or independently remains to be studied.
Collapse
Affiliation(s)
- Nanduri R Prabhakar
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, The University of Chicago, Chicago, IL, 60637, USA
| | - Ying-Jie Peng
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, The University of Chicago, Chicago, IL, 60637, USA
| | - Jayasri Nanduri
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, The University of Chicago, Chicago, IL, 60637, USA
| |
Collapse
|
22
|
Urra FA, Muñoz F, Córdova-Delgado M, Ramírez MP, Peña-Ahumada B, Rios M, Cruz P, Ahumada-Castro U, Bustos G, Silva-Pavez E, Pulgar R, Morales D, Varela D, Millas-Vargas JP, Retamal E, Ramírez-Rodríguez O, Pessoa-Mahana H, Pavani M, Ferreira J, Cárdenas C, Araya-Maturana R. FR58P1a; a new uncoupler of OXPHOS that inhibits migration in triple-negative breast cancer cells via Sirt1/AMPK/β1-integrin pathway. Sci Rep 2018; 8:13190. [PMID: 30181620 PMCID: PMC6123471 DOI: 10.1038/s41598-018-31367-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 08/17/2018] [Indexed: 02/06/2023] Open
Abstract
Highly malignant triple-negative breast cancer (TNBC) cells rely mostly on glycolysis to maintain cellular homeostasis; however, mitochondria are still required for migration and metastasis. Taking advantage of the metabolic flexibility of TNBC MDA-MB-231 cells to generate subpopulations with glycolytic or oxidative phenotypes, we screened phenolic compounds containing an ortho-carbonyl group with mitochondrial activity and identified a bromoalkyl-ester of hydroquinone named FR58P1a, as a mitochondrial metabolism-affecting compound that uncouples OXPHOS through a protonophoric mechanism. In contrast to well-known protonophore uncoupler FCCP, FR58P1a does not depolarize the plasma membrane and its effect on the mitochondrial membrane potential and bioenergetics is moderate suggesting a mild uncoupling of OXPHOS. FR58P1a activates AMPK in a Sirt1-dependent fashion. Although the activation of Sirt1/AMPK axis by FR58P1a has a cyto-protective role, selectively inhibits fibronectin-dependent adhesion and migration in TNBC cells but not in non-tumoral MCF10A cells by decreasing β1-integrin at the cell surface. Prolonged exposure to FR58P1a triggers a metabolic reprograming in TNBC cells characterized by down-regulation of OXPHOS-related genes that promote cell survival but comprise their ability to migrate. Taken together, our results show that TNBC cell migration is susceptible to mitochondrial alterations induced by small molecules as FR58P1a, which may have therapeutic implications.
Collapse
Affiliation(s)
- Félix A Urra
- Anatomy and Developmental Biology Program, Institute of Biomedical Sciences, University of Chile, Santiago, Chile.
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile.
| | - Felipe Muñoz
- Anatomy and Developmental Biology Program, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile
| | - Miguel Córdova-Delgado
- Departamento de Química Orgánica y Físico-Química, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Casilla 233, Santiago 1, Chile
| | - María Paz Ramírez
- Departamento de Química Orgánica y Físico-Química, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Casilla 233, Santiago 1, Chile
| | - Bárbara Peña-Ahumada
- Departamento de Química Orgánica y Físico-Química, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Casilla 233, Santiago 1, Chile
| | - Melany Rios
- Anatomy and Developmental Biology Program, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile
| | - Pablo Cruz
- Anatomy and Developmental Biology Program, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile
| | - Ulises Ahumada-Castro
- Anatomy and Developmental Biology Program, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile
| | - Galdo Bustos
- Anatomy and Developmental Biology Program, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile
| | - Eduardo Silva-Pavez
- Anatomy and Developmental Biology Program, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile
| | - Rodrigo Pulgar
- Laboratorio de Bioinformática y Expresión Génica, INTA-Universidad de Chile, El Líbano, 5524, Santiago, Chile
| | - Danna Morales
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, 8380453, Chile
| | - Diego Varela
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, 8380453, Chile
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Chile, Santiago, Chile
| | - Juan Pablo Millas-Vargas
- Departamento de Química Orgánica y Físico-Química, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Casilla 233, Santiago 1, Chile
| | - Evelyn Retamal
- Departamento de Química Orgánica y Físico-Química, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Casilla 233, Santiago 1, Chile
| | - Oney Ramírez-Rodríguez
- Campus Río Simpson, University of Aysén, Obispo Vielmo 62, Coyhaique, 5952122, Aysén, Chile
| | - Hernán Pessoa-Mahana
- Departamento de Química Orgánica y Físico-Química, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Casilla 233, Santiago 1, Chile
| | - Mario Pavani
- Programa de Farmacología Molecular y Clínica, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Independencia 1027, Casilla 7, Santiago, Chile
| | - Jorge Ferreira
- Programa de Farmacología Molecular y Clínica, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Independencia 1027, Casilla 7, Santiago, Chile
| | - César Cárdenas
- Anatomy and Developmental Biology Program, Institute of Biomedical Sciences, University of Chile, Santiago, Chile.
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile.
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California, 93106, United States.
- The Buck Institute for Research on Aging, Novato, CA, 94945, United States.
| | - Ramiro Araya-Maturana
- Instituto de Química de Recursos Naturales and Programa de Investigación Asociativa en Cáncer Gástrico, Universidad de Talca, casilla 747, Talca, Chile.
| |
Collapse
|
23
|
O'Donohoe PB, Huskens N, Turner PJ, Pandit JJ, Buckler KJ. A1899, PK-THPP, ML365, and Doxapram inhibit endogenous TASK channels and excite calcium signaling in carotid body type-1 cells. Physiol Rep 2018; 6:e13876. [PMID: 30284397 PMCID: PMC6170881 DOI: 10.14814/phy2.13876] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 08/24/2018] [Indexed: 01/10/2023] Open
Abstract
Sensing of hypoxia and acidosis in arterial chemoreceptors is thought to be mediated through the inhibition of TASK and possibly other (e.g., BKCa ) potassium channels which leads to membrane depolarization, voltage-gated Ca-entry, and neurosecretion. Here, we investigate the effects of pharmacological inhibitors on TASK channel activity and [Ca2+ ]i -signaling in isolated neonatal rat type-1 cells. PK-THPP inhibited TASK channel activity in cell attached patches by up to 90% (at 400 nmol/L). A1899 inhibited TASK channel activity by 35% at 400 nmol/L. PK-THPP, A1899 and Ml 365 all evoked a rapid increase in type-1 cell [Ca2+ ]i . These [Ca2+ ]i responses were abolished in Ca2+ -free solution and greatly attenuated by Ni2+ (2 mM) suggesting that depolarization and voltage-gated Ca2+ -entry mediated the rise in [Ca2+ ]i. Doxapram (50 μmol/L), a respiratory stimulant, also inhibited type-1 cell TASK channel activity and increased [Ca2+ ]i. . We also tested the effects of combined inhibition of BKCa and TASK channels. TEA (5 mmol/L) slightly increased [Ca2+ ]i in the presence of PK-THPP and A1899. Paxilline (300 nM) and iberiotoxin (50 nmol/L) also slightly increased [Ca2+ ]i in the presence of A1899 but not in the presence of PK-THPP. In general [Ca2+ ]i responses to TASK inhibitors, alone or in combination with BKCa inhibitors, were smaller than the [Ca2+ ]i responses evoked by hypoxia. These data confirm that TASK channel inhibition is capable of evoking membrane depolarization and robust voltage-gated Ca2+ -entry but suggest that this, even with concomitant inhibition of BKCa channels, may be insufficient to account fully for the [Ca2+ ]i -response to hypoxia.
Collapse
Affiliation(s)
- Peadar B. O'Donohoe
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUnited Kingdom
- Nuffield Department of AnaestheticsOxford University HospitalsOxfordUnited Kingdom
| | - Nicky Huskens
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUnited Kingdom
| | - Philip J. Turner
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUnited Kingdom
| | - Jaideep J. Pandit
- Nuffield Department of AnaestheticsOxford University HospitalsOxfordUnited Kingdom
| | - Keith J. Buckler
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUnited Kingdom
| |
Collapse
|
24
|
Kitamura K, Itoh H, Sakurai K, Dan S, Inoue M. Target Identification of Yaku’amide B and Its Two Distinct Activities against Mitochondrial FoF1-ATP Synthase. J Am Chem Soc 2018; 140:12189-12199. [DOI: 10.1021/jacs.8b07339] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Kai Kitamura
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hiroaki Itoh
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kaori Sakurai
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-shi, Tokyo 184-8588, Japan
| | - Shingo Dan
- Division of Molecular Pharmacology, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, 3-10-6 Ariake, Koto-ku, Tokyo 135-8550, Japan
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| |
Collapse
|
25
|
Popova LB, Nosikova ES, Kotova EA, Tarasova EO, Nazarov PA, Khailova LS, Balezina OP, Antonenko YN. Protonophoric action of triclosan causes calcium efflux from mitochondria, plasma membrane depolarization and bursts of miniature end-plate potentials. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1000-1007. [DOI: 10.1016/j.bbamem.2018.01.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 12/21/2017] [Accepted: 01/04/2018] [Indexed: 12/27/2022]
|
26
|
Lahuerta M, Aguado C, Sánchez-Martín P, Sanz P, Knecht E. Degradation of altered mitochondria by autophagy is impaired in Lafora disease. FEBS J 2018; 285:2071-2090. [PMID: 29645350 DOI: 10.1111/febs.14468] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 03/23/2018] [Accepted: 04/04/2018] [Indexed: 11/27/2022]
Abstract
Lafora disease (LD) is a fatal neurodegenerative disorder caused mostly by mutations in either of two genes encoding laforin and malin. LD is characterized by accumulation of a poorly branched form of glycogen in the cytoplasm of neurons and other cells. We previously reported dysfunctional mitochondria in different LD models. Now, using mitochondrial uncouplers and respiratory chain inhibitors, we have investigated with human fibroblasts a possible alteration in the selective degradation of damaged mitochondria (mitophagy) in LD. By flow cytometry of MitoTracker-labelled cells and measuring the levels of various mitochondrial proteins by western blot, we found in LD fibroblasts a partial impairment in the increased mitochondrial degradation produced by these treatments. In addition, colocalization of mitochondrial and lysosomal markers decreased in LD fibroblasts. All these results are consistent with a partial impairment in the induced autophagic degradation of dysfunctional mitochondria in LD fibroblasts. However, canonical recruitment of Parkin to mitochondria under these conditions remained unaffected in LD fibroblasts, and also in SH-SY5Y cells after malin and laforin overexpression. Neither mitochondrial localization nor protein levels of Bcl-2-like protein 13, another component of the mitophagic machinery that operates under these conditions, were affected in LD fibroblasts. In contrast, although these treatments raised autophagy in both control and LD fibroblasts, this enhanced autophagy was clearly lower in the latter cells. Therefore, the autophagic degradation of altered mitochondria is impaired in LD, which is due to a partial defect in the autophagic response and not in the canonical mitophagy signalling pathways.
Collapse
Affiliation(s)
| | - Carmen Aguado
- Centro de Investigación Príncipe Felipe, Valencia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain
| | - Pablo Sánchez-Martín
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain.,Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Pascual Sanz
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain.,Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Erwin Knecht
- Centro de Investigación Príncipe Felipe, Valencia, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain
| |
Collapse
|
27
|
Unraveling Synaptic GCaMP Signals: Differential Excitability and Clearance Mechanisms Underlying Distinct Ca 2+ Dynamics in Tonic and Phasic Excitatory, and Aminergic Modulatory Motor Terminals in Drosophila. eNeuro 2018; 5:eN-NWR-0362-17. [PMID: 29464198 PMCID: PMC5818553 DOI: 10.1523/eneuro.0362-17.2018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 01/27/2018] [Accepted: 02/02/2018] [Indexed: 11/21/2022] Open
Abstract
GCaMP is an optogenetic Ca2+ sensor widely used for monitoring neuronal activities but the precise physiological implications of GCaMP signals remain to be further delineated among functionally distinct synapses. The Drosophila neuromuscular junction (NMJ), a powerful genetic system for studying synaptic function and plasticity, consists of tonic and phasic glutamatergic and modulatory aminergic motor terminals of distinct properties. We report a first simultaneous imaging and electric recording study to directly contrast the frequency characteristics of GCaMP signals of the three synapses for physiological implications. Different GCaMP variants were applied in genetic and pharmacological perturbation experiments to examine the Ca2+ influx and clearance processes underlying the GCaMP signal. Distinct mutational and drug effects on GCaMP signals indicate differential roles of Na+ and K+ channels, encoded by genes including paralytic (para), Shaker (Sh), Shab, and ether-a-go-go (eag), in excitability control of different motor terminals. Moreover, the Ca2+ handling properties reflected by the characteristic frequency dependence of the synaptic GCaMP signals were determined to a large extent by differential capacity of mitochondria-powered Ca2+ clearance mechanisms. Simultaneous focal recordings of synaptic activities further revealed that GCaMPs were ineffective in tracking the rapid dynamics of Ca2+ influx that triggers transmitter release, especially during low-frequency activities, but more adequately reflected cytosolic residual Ca2+ accumulation, a major factor governing activity-dependent synaptic plasticity. These results highlight the vast range of GCaMP response patterns in functionally distinct synaptic types and provide relevant information for establishing basic guidelines for the physiological interpretations of presynaptic GCaMP signals from in situ imaging studies.
Collapse
|
28
|
Arduino DM, Perocchi F. Pharmacological modulation of mitochondrial calcium homeostasis. J Physiol 2018; 596:2717-2733. [PMID: 29319185 DOI: 10.1113/jp274959] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 12/13/2017] [Indexed: 12/26/2022] Open
Abstract
Mitochondria are pivotal organelles in calcium (Ca2+ ) handling and signalling, constituting intracellular checkpoints for numerous processes that are vital for cell life. Alterations in mitochondrial Ca2+ homeostasis have been linked to a variety of pathological conditions and are critical in the aetiology of several human diseases. Efforts have been taken to harness mitochondrial Ca2+ transport mechanisms for therapeutic intervention, but pharmacological compounds that direct and selectively modulate mitochondrial Ca2+ homeostasis are currently lacking. New avenues have, however, emerged with the breakthrough discoveries on the genetic identification of the main players involved in mitochondrial Ca2+ influx and efflux pathways and with recent hints towards a deep understanding of the function of these molecular systems. Here, we review the current advances in the understanding of the mechanisms and regulation of mitochondrial Ca2+ homeostasis and its contribution to physiology and human disease. We also introduce and comment on the recent progress towards a systems-level pharmacological targeting of mitochondrial Ca2+ homeostasis.
Collapse
Affiliation(s)
- Daniela M Arduino
- Gene Center, Department of Biochemistry, Ludwig-Maximilians Universität München, Munich, 81377, Germany.,Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München and German National Diabetes Center (DZD), Neuherberg, 85764, Germany
| | - Fabiana Perocchi
- Gene Center, Department of Biochemistry, Ludwig-Maximilians Universität München, Munich, 81377, Germany.,Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München and German National Diabetes Center (DZD), Neuherberg, 85764, Germany
| |
Collapse
|
29
|
Childress ES, Alexopoulos SJ, Hoehn KL, Santos WL. Small Molecule Mitochondrial Uncouplers and Their Therapeutic Potential. J Med Chem 2017; 61:4641-4655. [DOI: 10.1021/acs.jmedchem.7b01182] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Elizabeth S. Childress
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Stephanie J. Alexopoulos
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - Kyle L. Hoehn
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
- Departments of Pharmacology and Medicine, Cardiovascular Research Center, and Emily Couric Clinical Cancer Center, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Webster L. Santos
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| |
Collapse
|
30
|
Cytoprotective propensity of green tea polyphenols against citrinin-induced skeletal-myotube damage in C2C12 cells. Cytotechnology 2017; 69:681-697. [PMID: 28536872 DOI: 10.1007/s10616-017-0077-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 03/02/2017] [Indexed: 01/08/2023] Open
Abstract
The mycotoxin citrinin, is produced by several species of Penicillium, Aspergillus and Monascus, and is capable of inducing cytotoxicity, oxidative stress and apoptosis. The aim of the present study was to investigate the effect of citrinin in mouse skeletal muscle cells (C2C12) and to overcome the cellular adverse effects by supplementing green tea extract (GTE) rich in polyphenols. C2C12 myoblasts were differentiated to myotubes and were exposed to citrinin in a dose dependent manner (0-100 µM) for 24 h and IC50 value was found to be 100 µM that resulted in decreased cell viability, increased LDH leakage and compromised membrane integrity. Mitochondrial membrane potential loss, increased accumulation of intracellular ROS and sub G1 phase of cell cycle was observed. To ameliorate the cytotoxic effects of CTN, C2C12 cells were pretreated with GTE (20, 40, 80 µg/ml) for 2 h followed by citrinin (100 µM) treatment for 24 h. GTE pretreatment combated citrinin-induced cytotoxicity and oxidative stress. GTE at 40 and 80 µg/ml significantly promoted cell survival and upregulated antioxidant enzyme activities (CAT, SOD, GPx) and endogenous antioxidant GSH, while the gene and protein expression levels were significantly restored through its effective antioxidant mechanism. Present study results suggested the antioxidant properties of GTE as a herbal source in ameliorating the citrinin-induced oxidative stress.
Collapse
|
31
|
Garner T, Ouyang A, Berrones AJ, Campbell MS, Du B, Fleenor BS. Sweet potato (Ipomoea batatas) attenuates diet-induced aortic stiffening independent of changes in body composition. Appl Physiol Nutr Metab 2017; 42:802-809. [PMID: 28288284 DOI: 10.1139/apnm-2016-0571] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We hypothesized a sweet potato intervention would prevent high-fat (HF) diet-induced aortic stiffness, which would be associated with decreased arterial oxidative stress and increased mitochondrial uncoupling. Young (8-week old) C57BL/6J mice were randomly divided into 4 groups: low fat (LF; 10% fat), HF (60% fat), low-fat sweet potato (LFSP; 10% fat containing 260.3 μg/kcal sweet potato), or high-fat sweet potato diet (HFSP; 60% fat containing 260.3 μg/kcal sweet potato) for 16 weeks. Compared with LF and LFSP, HF- and HFSP-fed mice had increased body mass and percent fat mass with lower percent lean mass (all, P < 0.05). Sweet potato intervention did not influence body composition (all, P > 0.05). Arterial stiffness, assessed by aortic pulse wave velocity and ex vivo mechanical testing of the elastin region elastic modulus (EEM) was greater in HF compared with LF and HFSP animals (all, P < 0.05). Advanced glycation end products and nitrotyrosine abundance were greater in aortic segments from HF mice compared with LF and HFSP animals (all, P < 0.05). Aortic elastin and uncoupling protein 2 expressions, however, were reduced in HF compared with LF and HFSP mice (all, P < 0.05). Aortic segments cultured with 2,4-dinitrophenol (DNP), a mitochondrial uncoupler, for 72 h reduced the EEM of HF arteries compared with nontreated HF segments (P < 0.05). DNP had no effect on the EEM of aortic segments from HFSP mice. In conclusion, sweet potato attenuates diet-induced aortic stiffness independent of body mass and composition, which is associated with a normalization of arterial oxidative stress possibly due to mitochondrial uncoupling.
Collapse
Affiliation(s)
- Tyler Garner
- a Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, KY 40506, USA
| | - An Ouyang
- a Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, KY 40506, USA
| | - Adam J Berrones
- a Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, KY 40506, USA
| | - Marilyn S Campbell
- a Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, KY 40506, USA
| | - Bing Du
- b Department of Cardiology, The First Hospital of Jilin University, Changchun 130000, China
| | - Bradley S Fleenor
- a Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, KY 40506, USA
| |
Collapse
|
32
|
Rehman AU, Anwer AG, Gosnell ME, Mahbub SB, Liu G, Goldys EM. Fluorescence quenching of free and bound NADH in HeLa cells determined by hyperspectral imaging and unmixing of cell autofluorescence. BIOMEDICAL OPTICS EXPRESS 2017; 8:1488-1498. [PMID: 28663844 PMCID: PMC5480559 DOI: 10.1364/boe.8.001488] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 01/12/2017] [Accepted: 02/06/2017] [Indexed: 05/06/2023]
Abstract
Carbonyl cyanide-p-trifluoro methoxyphenylhydrazone (FCCP) is a well-known mitochondrial uncoupling agent. We examined FCCP-induced fluorescence quenching of reduced nicotinamide adenine dinucleotide / nicotinamide adenine dinucleotide phosphate (NAD(P)H) in solution and in cultured HeLa cells in a wide range of FCCP concentrations from 50 to 1000µM. A non-invasive label-free method of hyperspectral imaging of cell autofluorescence combined with unsupervised unmixing was used to separately isolate the emissions of free and bound NAD(P)H from cell autofluorescence. Hyperspectral image analysis of FCCP-treated HeLa cells confirms that this agent selectively quenches fluorescence of free and bound NAD(P)H in a broad range of concentrations. This is confirmed by the measurements of average NAD/NADH and NADP/NADPH content in cells. FCCP quenching of free NAD(P)H in cells and in solution is found to be similar, but quenching of bound NAD(P)H in cells is attenuated compared to solution quenching possibly due to a contribution from the metabolic and/or antioxidant response in cells. Chemical quenching of NAD(P)H fluorescence by FCCP validates the results of unsupervised unmixing of cell autofluorescence.
Collapse
Affiliation(s)
- Aziz Ul Rehman
- ARC Centre of Excellence in Nanoscale Biophotonics, Macquarie University, Sydney, 2109, New South Wales, Australia
- Biophotonics Laboratory, National Institute of Lasers and Optronics, Lehtrar Road, Islamabad 45650, Pakistan
| | - Ayad G. Anwer
- ARC Centre of Excellence in Nanoscale Biophotonics, Macquarie University, Sydney, 2109, New South Wales, Australia
| | - Martin E. Gosnell
- ARC Centre of Excellence in Nanoscale Biophotonics, Macquarie University, Sydney, 2109, New South Wales, Australia
- Quantitative Pty Ltd, ABN 17 165 684 186, Australia
| | - Saabah B. Mahbub
- ARC Centre of Excellence in Nanoscale Biophotonics, Macquarie University, Sydney, 2109, New South Wales, Australia
| | - Guozhen Liu
- ARC Centre of Excellence in Nanoscale Biophotonics, Macquarie University, Sydney, 2109, New South Wales, Australia
- Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, China
| | - Ewa M. Goldys
- ARC Centre of Excellence in Nanoscale Biophotonics, Macquarie University, Sydney, 2109, New South Wales, Australia
| |
Collapse
|
33
|
Diclofenac induces proteasome and mitochondrial dysfunction in murine cardiomyocytes and hearts. Int J Cardiol 2016; 223:923-935. [PMID: 27589040 DOI: 10.1016/j.ijcard.2016.08.233] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 07/28/2016] [Accepted: 08/12/2016] [Indexed: 12/31/2022]
Abstract
BACKGROUND One of the most common nonsteroidal anti-inflammatory drugs (NSAIDs) used worldwide, diclofenac (DIC), has been linked to increased risk of cardiovascular disease (CVD). The molecular mechanism(s) by which DIC causes CVD is unknown. METHODS Proteasome activities were studied in hearts, livers, and kidneys from male Swiss Webster mice treated with either 100mg/kg DIC for 18h (acute treatment) or 10mg/kg DIC for 28days (chronic treatment). Cultured H9c2 cells and neonatal cardiomyocytes were also treated with different concentrations of DIC and proteasome function, cell death and ROS generation studied. Isolated mouse heart mitochondria were utilized to determine the effect of DIC on various electron transport chain complex activities. RESULTS DIC significantly inhibited the chymotrypsin-like proteasome activity in rat cardiac H9c2 cells, murine neonatal cardiomyocytes, and mouse hearts, but did not affect proteasome subunit expression levels. Proteasome activity was also affected in liver and kidney tissues from DIC treated animals. The levels of polyubiquitinated proteins increased in hearts from DIC treated mice. Importantly, the levels of oxidized proteins increased while the β5i immunoproteasome activity decreased in hearts from DIC treated mice. DIC increased ROS production and cell death in H9c2 cells and neonatal cardiomyocytes while the cardioprotective NSAID, aspirin, had no effect on ROS levels or cell viability. DIC inhibited mitochondrial Complex III, a major source of ROS, and impaired mitochondrial membrane potential suggesting that mitochondria are the major sites of ROS generation. CONCLUSION These results suggest that DIC induces cardiotoxicity by a ROS dependent mechanism involving mitochondrial and proteasome dysfunction.
Collapse
|
34
|
Dejonghe W, Kuenen S, Mylle E, Vasileva M, Keech O, Viotti C, Swerts J, Fendrych M, Ortiz-Morea FA, Mishev K, Delang S, Scholl S, Zarza X, Heilmann M, Kourelis J, Kasprowicz J, Nguyen LSL, Drozdzecki A, Van Houtte I, Szatmári AM, Majda M, Baisa G, Bednarek SY, Robert S, Audenaert D, Testerink C, Munnik T, Van Damme D, Heilmann I, Schumacher K, Winne J, Friml J, Verstreken P, Russinova E. Mitochondrial uncouplers inhibit clathrin-mediated endocytosis largely through cytoplasmic acidification. Nat Commun 2016; 7:11710. [PMID: 27271794 PMCID: PMC4899852 DOI: 10.1038/ncomms11710] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 04/21/2016] [Indexed: 11/27/2022] Open
Abstract
ATP production requires the establishment of an electrochemical proton gradient across the inner mitochondrial membrane. Mitochondrial uncouplers dissipate this proton gradient and disrupt numerous cellular processes, including vesicular trafficking, mainly through energy depletion. Here we show that Endosidin9 (ES9), a novel mitochondrial uncoupler, is a potent inhibitor of clathrin-mediated endocytosis (CME) in different systems and that ES9 induces inhibition of CME not because of its effect on cellular ATP, but rather due to its protonophore activity that leads to cytoplasm acidification. We show that the known tyrosine kinase inhibitor tyrphostinA23, which is routinely used to block CME, displays similar properties, thus questioning its use as a specific inhibitor of cargo recognition by the AP-2 adaptor complex via tyrosine motif-based endocytosis signals. Furthermore, we show that cytoplasm acidification dramatically affects the dynamics and recruitment of clathrin and associated adaptors, and leads to reduction of phosphatidylinositol 4,5-biphosphate from the plasma membrane. Plant cells maintain strict proton gradients over different membranes. Here, Dejonghe et al. show that several protonophores, including the known tyrosine kinase inhibitor TyrphostinA23, inhibit clathrin-mediated endocytosis by disturbing these gradients and causing cytoplasmic acidification.
Collapse
Affiliation(s)
- Wim Dejonghe
- Department of Plant Systems Biology, VIB, 9052 Gent, Belgium.,Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
| | - Sabine Kuenen
- VIB Center for the Biology of Disease, Laboratory of Neuronal Communication, 3000 Leuven, Belgium.,Department for Human Genetics, and Leuven Institute for Neurodegenerative Diseases, KU Leuven, 3000 Leuven, Belgium
| | - Evelien Mylle
- Department of Plant Systems Biology, VIB, 9052 Gent, Belgium.,Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
| | - Mina Vasileva
- Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
| | - Olivier Keech
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, 90187 Umeå, Sweden
| | - Corrado Viotti
- Department of Plant Physiology, Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam, Germany
| | - Jef Swerts
- VIB Center for the Biology of Disease, Laboratory of Neuronal Communication, 3000 Leuven, Belgium.,Department for Human Genetics, and Leuven Institute for Neurodegenerative Diseases, KU Leuven, 3000 Leuven, Belgium
| | - Matyáš Fendrych
- Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
| | - Fausto Andres Ortiz-Morea
- Department of Plant Systems Biology, VIB, 9052 Gent, Belgium.,Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
| | - Kiril Mishev
- Department of Plant Systems Biology, VIB, 9052 Gent, Belgium.,Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
| | - Simon Delang
- Developmental Biology of Plants, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany
| | - Stefan Scholl
- Developmental Biology of Plants, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany
| | - Xavier Zarza
- Department of Plant Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, 1090 GE Amsterdam, The Netherlands
| | - Mareike Heilmann
- Department of Cellular Biochemistry, Institute for Biochemistry and Biotechnology, Martin-Luther-University, 06120 Halle, Germany
| | - Jiorgos Kourelis
- Department of Plant Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, 1090 GE Amsterdam, The Netherlands
| | - Jaroslaw Kasprowicz
- VIB Center for the Biology of Disease, Laboratory of Neuronal Communication, 3000 Leuven, Belgium.,Department for Human Genetics, and Leuven Institute for Neurodegenerative Diseases, KU Leuven, 3000 Leuven, Belgium
| | | | | | - Isabelle Van Houtte
- Department of Plant Systems Biology, VIB, 9052 Gent, Belgium.,Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
| | - Anna-Mária Szatmári
- Department of Plant Systems Biology, VIB, 9052 Gent, Belgium.,Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
| | - Mateusz Majda
- Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden
| | - Gary Baisa
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | | | - Stéphanie Robert
- Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences, 90183 Umeå, Sweden
| | | | - Christa Testerink
- Department of Plant Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, 1090 GE Amsterdam, The Netherlands
| | - Teun Munnik
- Department of Plant Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, 1090 GE Amsterdam, The Netherlands
| | - Daniël Van Damme
- Department of Plant Systems Biology, VIB, 9052 Gent, Belgium.,Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
| | - Ingo Heilmann
- Department of Cellular Biochemistry, Institute for Biochemistry and Biotechnology, Martin-Luther-University, 06120 Halle, Germany
| | - Karin Schumacher
- Developmental Biology of Plants, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany
| | - Johan Winne
- Laboratory for Organic Synthesis, Department of Organic and Macromolecular Chemistry, Ghent University, 9000 Gent, Belgium
| | - Jiří Friml
- Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria
| | - Patrik Verstreken
- VIB Center for the Biology of Disease, Laboratory of Neuronal Communication, 3000 Leuven, Belgium.,Department for Human Genetics, and Leuven Institute for Neurodegenerative Diseases, KU Leuven, 3000 Leuven, Belgium
| | - Eugenia Russinova
- Department of Plant Systems Biology, VIB, 9052 Gent, Belgium.,Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052 Gent, Belgium
| |
Collapse
|
35
|
Buckler KJ, Turner PJ. Functional Properties of Mitochondria in the Type-1 Cell and Their Role in Oxygen Sensing. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 860:69-80. [PMID: 26303469 DOI: 10.1007/978-3-319-18440-1_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The identity of the oxygen sensor in arterial chemoreceptors has been the subject of much speculation. One of the oldest hypotheses is that oxygen is sensed through oxidative phosphorylation. There is a wealth of data demonstrating that arterial chemoreceptors are excited by inhibitors of oxidative phosphorylation. These compounds mimic the effects of hypoxia inhibiting TASK1/3 potassium channels causing membrane depolarisation calcium influx and neurosecretion. The TASK channels of Type-I cells are also sensitive to cytosolic MgATP. The existence of a metabolic signalling pathway in Type-1 cells is thus established; the contentious issue is whether this pathway is also used for acute oxygen sensing. The main criticism is that because cytochrome oxidase has a high affinity for oxygen (P50 ≈ 0.2 mmHg) mitochondrial metabolism should be insensitive to physiological hypoxia. This argument is however predicated on the assumption that chemoreceptor mitochondria are analogous to those of other tissues. We have however obtained new evidence to support the hypothesis that type-1 cell mitochondria are not like those of other cells in that they have an unusually low affinity for oxygen (Mills E, Jobsis FF, J Neurophysiol 35(4):405-428, 1972; Duchen MR, Biscoe TJ, J Physiol 450:13-31, 1992a). Our data confirm that mitochondrial membrane potential, NADH, electron transport and cytochrome oxidase activity in the Type-1 cell are all highly sensitive to hypoxia. These observations not only provide exceptionally strong support for the metabolic hypothesis but also reveal an unknown side of mitochondrial behaviour.
Collapse
Affiliation(s)
- Keith J Buckler
- Department of Physiology Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK,
| | | |
Collapse
|
36
|
Mlejnek P, Dolezel P. Loss of mitochondrial transmembrane potential and glutathione depletion are not sufficient to account for induction of apoptosis by carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone in human leukemia K562 cells. Chem Biol Interact 2015; 239:100-10. [DOI: 10.1016/j.cbi.2015.06.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 06/07/2015] [Accepted: 06/22/2015] [Indexed: 12/20/2022]
|
37
|
Structure-activity relationships of furazano[3,4-b]pyrazines as mitochondrial uncouplers. Bioorg Med Chem Lett 2015; 25:4858-4861. [PMID: 26119501 DOI: 10.1016/j.bmcl.2015.06.040] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 06/09/2015] [Accepted: 06/11/2015] [Indexed: 11/21/2022]
Abstract
Chemical mitochondrial uncouplers are lipophilic weak acids that transport protons into the mitochondrial matrix via a pathway that is independent of ATP synthase, thereby uncoupling nutrient oxidation from ATP production. These uncouplers have potential for the treatment of diseases such as obesity, Parkinson's disease, and aging. We have previously identified a novel mitochondrial protonophore, named BAM15, which stimulates mitochondrial respiration across a broad dosing range compared to carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP). Herein, we report our investigations on the structure-activity relationship profile of BAM15. Our studies demonstrate the importance of the furazan, pyrazine, and aniline rings as well as pKa in maintaining its effective protonophore activity.
Collapse
|
38
|
Krishnan V, Gleason E. Nitric oxide releases Cl(-) from acidic organelles in retinal amacrine cells. Front Cell Neurosci 2015; 9:213. [PMID: 26106295 PMCID: PMC4459082 DOI: 10.3389/fncel.2015.00213] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 05/19/2015] [Indexed: 02/03/2023] Open
Abstract
Determining the factors regulating cytosolic Cl(-) in neurons is fundamental to our understanding of the function of GABA- and glycinergic synapses. This is because the Cl(-) distribution across the postsynaptic plasma membrane determines the sign and strength of postsynaptic voltage responses. We have previously demonstrated that nitric oxide (NO) releases Cl(-) into the cytosol from an internal compartment in both retinal amacrine cells and hippocampal neurons. Furthermore, we have shown that the increase in cytosolic Cl(-) is dependent upon a decrease in cytosolic pH. Here, our goals were to confirm the compartmental nature of the internal Cl(-) store and to test the hypothesis that Cl(-) is being released from acidic organelles (AO) such as the Golgi, endosomes or lysosomes. To achieve this, we made whole cell voltage clamp recordings from cultured chick retinal amacrine cells and used GABA-gated currents to track changes in cytosolic Cl(-). Our results demonstrate that intact internal proton gradients are required for the NO-dependent release of internal Cl(-). Furthermore, we demonstrate that increasing the pH of AO leads to release of Cl(-) into the cytosol. Intriguingly, the elevation of organellar pH results in a reversal in the effects of NO. These results demonstrate that cytosolic Cl(-) is closely linked to the regulation and maintenance of organellar pH and provide evidence that acidic compartments are the target of NO.
Collapse
Affiliation(s)
- Vijai Krishnan
- Department of Biological Sciences, Louisiana State University Baton Rouge, LA, USA
| | - Evanna Gleason
- Department of Biological Sciences, Louisiana State University Baton Rouge, LA, USA
| |
Collapse
|
39
|
The cellular and molecular progression of mitochondrial dysfunction induced by 2,4-dinitrophenol in developing zebrafish embryos. Differentiation 2015; 89:51-69. [PMID: 25771346 DOI: 10.1016/j.diff.2015.01.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 01/22/2015] [Accepted: 01/27/2015] [Indexed: 12/18/2022]
Abstract
The etiology of mitochondrial disease is poorly understood. Furthermore, treatment options are limited, and diagnostic methods often lack the sensitivity to detect disease in its early stages. Disrupted oxidative phosphorylation (OXPHOS) that inhibits ATP production is a common phenotype of mitochondrial disorders that can be induced in zebrafish by exposure to 2,4-dinitrophenol (DNP), a FDA-banned weight-loss agent and EPA-regulated environmental toxicant, traditionally used in research labs as an uncoupler of OXPHOS. Despite the DNP-induced OXPHOS inhibition we observed using in vivo respirometry, the development of the DNP-treated and control zebrafish were largely similar during the first half of embryogenesis. During this period, DNP-treated embryos induced gene expression of mitochondrial and nuclear genes that stimulated the production of new mitochondria and increased glycolysis to yield normal levels of ATP. DNP-treated embryos were incapable of sustaining this mitochondrial biogenic response past mid-embryogenesis, as shown by significantly lowered ATP production and ATP levels, decreased gene expression, and the onset of developmental defects. Examining neural tissues commonly affected by mitochondrial disease, we found that DNP exposure also inhibited motor neuron axon arbor outgrowth and the proper formation of the retina. We observed and quantified the molecular and physiological progression of mitochondrial dysfunction during development with this new model of OXPHOS dysfunction, which has great potential for use in diagnostics and therapies for mitochondrial disease.
Collapse
|
40
|
TASK channels in arterial chemoreceptors and their role in oxygen and acid sensing. Pflugers Arch 2015; 467:1013-25. [PMID: 25623783 PMCID: PMC4428840 DOI: 10.1007/s00424-015-1689-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 01/06/2015] [Accepted: 01/07/2015] [Indexed: 01/05/2023]
Abstract
Arterial chemoreceptors play a vital role in cardiorespiratory control by providing the brain with information regarding blood oxygen, carbon dioxide, and pH. The main chemoreceptor, the carotid body, is composed of sensory (type 1) cells which respond to hypoxia or acidosis with a depolarising receptor potential which in turn activates voltage-gated calcium entry, neurosecretion and excitation of adjacent afferent nerves. The receptor potential is generated by inhibition of Twik-related acid-sensitive K(+) channel 1 and 3 (TASK1/TASK3) heterodimeric channels which normally maintain the cells' resting membrane potential. These channels are thought to be directly inhibited by acidosis. Oxygen sensitivity, however, probably derives from a metabolic signalling pathway. The carotid body, isolated type 1 cells, and all forms of TASK channel found in the type 1 cell, are highly sensitive to inhibitors of mitochondrial metabolism. Moreover, type1 cell TASK channels are activated by millimolar levels of MgATP. In addition to their role in the transduction of chemostimuli, type 1 cell TASK channels have also been implicated in the modulation of chemoreceptor function by a number of neurocrine/paracrine signalling molecules including adenosine, GABA, and serotonin. They may also be instrumental in mediating the depression of the acute hypoxic ventilatory response that occurs with some general anaesthetics. Modulation of TASK channel activity is therefore a key mechanism by which the excitability of chemoreceptors can be controlled. This is not only of physiological importance but may also offer a therapeutic strategy for the treatment of cardiorespiratory disorders that are associated with chemoreceptor dysfunction.
Collapse
|
41
|
Tomcin S, Baier G, Landfester K, Mailänder V. Pharmacokinetics on a microscale: visualizing Cy5-labeled oligonucleotide release from poly(n-butylcyanoacrylate) nanocapsules in cells. Int J Nanomedicine 2014; 9:5471-89. [PMID: 25473285 PMCID: PMC4251750 DOI: 10.2147/ijn.s70908] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
For successful design of a nanoparticulate drug delivery system, the fate of the carrier and cargo need to be followed. In this work, we fluorescently labeled poly(n-butylcyanoacrylate) (PBCA) nanocapsules as a shell and separately an oligonucleotide (20 mer) as a payload. The nanocapsules were formed by interfacial anionic polymerization on aqueous droplets generated by an inverse miniemulsion process. After uptake, the PBCA capsules were shown to be round-shaped, endosomal structures and the payload was successfully released. Cy5-labeled oligonucleotides accumulated at the mitochondrial membrane due to a combination of the high mitochondrial membrane potential and the specific molecular structure of Cy5. The specificity of this accumulation at the mitochondria was shown as the uncoupler dinitrophenol rapidly diminished the accumulation of the Cy5-labeled oligonucleotide. Importantly, a fluorescence resonance energy transfer investigation showed that the dye-labeled cargo (Cy3/Cy5-labeled oligonucleotides) reached its target site without degradation during escape from an endosomal compartment to the cytoplasm. The time course of accumulation of fluorescent signals at the mitochondria was determined by evaluating the colocalization of Cy5-labeled oligonucleotides and mitochondrial markers for up to 48 hours. As oligonucleotides are an ideal model system for small interfering RNA PBCA nanocapsules demonstrate to be a versatile delivery platform for small interfering RNA to treat a variety of diseases.
Collapse
Affiliation(s)
- Stephanie Tomcin
- Max Planck Institute for Polymer Research, III Medical Clinic, Mainz, Germany
| | - Grit Baier
- Max Planck Institute for Polymer Research, III Medical Clinic, Mainz, Germany
| | | | - Volker Mailänder
- Max Planck Institute for Polymer Research, III Medical Clinic, Mainz, Germany ; University Medical Center of the Johannes Gutenberg University, III Medical Clinic, Mainz, Germany
| |
Collapse
|
42
|
Padmaraj D, Pande R, Miller JH, Wosik J, Zagozdzon-Wosik W. Mitochondrial membrane studies using impedance spectroscopy with parallel pH monitoring. PLoS One 2014; 9:e101793. [PMID: 25010497 PMCID: PMC4091947 DOI: 10.1371/journal.pone.0101793] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 06/11/2014] [Indexed: 11/18/2022] Open
Abstract
A biological microelectromechanical system (BioMEMS) device was designed to study complementary mitochondrial parameters important in mitochondrial dysfunction studies. Mitochondrial dysfunction has been linked to many diseases, including diabetes, obesity, heart failure and aging, as these organelles play a critical role in energy generation, cell signaling and apoptosis. The synthesis of ATP is driven by the electrical potential across the inner mitochondrial membrane and by the pH difference due to proton flux across it. We have developed a tool to study the ionic activity of the mitochondria in parallel with dielectric measurements (impedance spectroscopy) to gain a better understanding of the properties of the mitochondrial membrane. This BioMEMS chip includes: 1) electrodes for impedance studies of mitochondria designed as two- and four-probe structures for optimized operation over a wide frequency range and 2) ion-sensitive field effect transistors for proton studies of the electron transport chain and for possible monitoring other ions such as sodium, potassium and calcium. We have used uncouplers to depolarize the mitochondrial membrane and disrupt the ionic balance. Dielectric spectroscopy responded with a corresponding increase in impedance values pointing at changes in mitochondrial membrane potential. An electrical model was used to describe mitochondrial sample’s complex impedance frequency dependencies and the contribution of the membrane to overall impedance changes. The results prove that dielectric spectroscopy can be used as a tool for membrane potential studies. It can be concluded that studies of the electrochemical parameters associated with mitochondrial bioenergetics may render significant information on various abnormalities attributable to these organelles.
Collapse
Affiliation(s)
- Divya Padmaraj
- Electrical and Computer Engineering Department, University of Houston, Houston, Texas, United States of America
- Texas Center for Superconductivity, University of Houston, Houston, Texas, United States of America
| | - Rohit Pande
- Electrical and Computer Engineering Department, University of Houston, Houston, Texas, United States of America
- Texas Center for Superconductivity, University of Houston, Houston, Texas, United States of America
| | - John H. Miller
- Texas Center for Superconductivity, University of Houston, Houston, Texas, United States of America
- Physics Department, University of Houston, Houston, Texas, United States of America
| | - Jarek Wosik
- Electrical and Computer Engineering Department, University of Houston, Houston, Texas, United States of America
- Texas Center for Superconductivity, University of Houston, Houston, Texas, United States of America
| | - Wanda Zagozdzon-Wosik
- Electrical and Computer Engineering Department, University of Houston, Houston, Texas, United States of America
- * E-mail:
| |
Collapse
|
43
|
Porteus CS, Abdallah SJ, Pollack J, Kumai Y, Kwong RWM, Yew HM, Milsom WK, Perry SF. The role of hydrogen sulphide in the control of breathing in hypoxic zebrafish (Danio rerio). J Physiol 2014; 592:3075-88. [PMID: 24756639 DOI: 10.1113/jphysiol.2014.271098] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The current study investigated the role of hydrogen sulphide (H2S) in oxygen sensing, intracellular signalling and promotion of ventilatory responses to hypoxia in adult and larval zebrafish (Danio rerio). Both larval and adult zebrafish exhibited a dose-dependent increase in ventilation to sodium sulphide (Na2S), an H2S donor. In vertebrates, cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) are enzymes that catalyse the endogenous production of H2S. In adult zebrafish, inhibition of both CBS and CSE with aminooxyacetate (AOA) and propargyl glycine (PPG) blunted or abolished the hypoxic hyperventilation, and the addition of Na2S to the water partially rescued the effects of inhibiting endogenous H2S production. In zebrafish larvae (4 days post-fertilization), gene knockdown of either CBS or CSE using morpholinos attenuated the hypoxic ventilatory response. Furthermore, the intracellular calcium concentration of isolated neuroepithelial cells (NECs), which are putative oxygen chemoreceptors, increased significantly when these cells were exposed to 50 μm Na2S, supporting a role for H2S in Ca(2+)-evoked neurotransmitter release in these cells. Finally, immunohistochemical labelling showed that NECs dissociated from adult gill contained CBS and CSE, whereas cutaneous NECs in larval zebrafish expressed only CSE. Taken together, these data show that H2S can be produced in the putative oxygen-sensing cells of zebrafish, the NECs, in which it appears to play a pivotal role in promoting the hypoxic ventilatory response.
Collapse
Affiliation(s)
- Cosima S Porteus
- Department of Biosciences, University of British Columbia, Vancouver, BC, Canada
| | - Sara J Abdallah
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - Jacob Pollack
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - Yusuke Kumai
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | | | - Hong M Yew
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - William K Milsom
- Department of Biosciences, University of British Columbia, Vancouver, BC, Canada
| | - Steve F Perry
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| |
Collapse
|
44
|
Kim D, Kang D, Martin EA, Kim I, Carroll JL. Effects of modulators of AMP-activated protein kinase on TASK-1/3 and intracellular Ca(2+) concentration in rat carotid body glomus cells. Respir Physiol Neurobiol 2014; 195:19-26. [PMID: 24530802 DOI: 10.1016/j.resp.2014.01.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 01/29/2014] [Accepted: 01/30/2014] [Indexed: 01/11/2023]
Abstract
Acute hypoxia depolarizes carotid body chemoreceptor (glomus) cells and elevates intracellular Ca(2+) concentration ([Ca(2+)]i). Recent studies suggest that AMP-activated protein kinase (AMPK) mediates these effects of hypoxia by inhibiting the background K(+) channels such as TASK. Here we studied the effects of modulators of AMPK on TASK activity in cell-attached patches. Activators of AMPK (1mM AICAR and 0.1-0.5mM A769662) did not inhibit TASK activity or cause depolarization during acute (10min) or prolonged (2-3h) exposure. Hypoxia inhibited TASK activity by ∼70% in cells pretreated with AICAR or A769662. Both AICAR and A769662 (15-40min) failed to increase [Ca(2+)]i in glomus cells. Compound C (40μM), an inhibitor of AMPK, showed no effect on hypoxia-induced inhibition of TASK. AICAR and A769662 phosphorylated AMPKα in PC12 cells, and Compound C blocked the phosphorylation. Our results suggest that AMPK does not affect TASK activity and is not involved in hypoxia-induced elevation of intracellular [Ca(2+)] in isolated rat carotid body glomus cells.
Collapse
Affiliation(s)
- Donghee Kim
- Department of Physiology and Biophysics, Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064, United States.
| | - Dawon Kang
- Department of Physiology and Biophysics, Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064, United States; Department of Physiology and Institute of Health Sciences, Gyeongsang National University School of Medicine, 90 Chilam, Jinju 660-751, Republic of Korea
| | - Elizabeth A Martin
- Department of Physiology and Biophysics, Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064, United States
| | - Insook Kim
- Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital Research Institute, 1 Children's Way, Little Rock, AR 72202, United States
| | - John L Carroll
- Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital Research Institute, 1 Children's Way, Little Rock, AR 72202, United States.
| |
Collapse
|
45
|
Kenwood BM, Weaver JL, Bajwa A, Poon IK, Byrne FL, Murrow BA, Calderone JA, Huang L, Divakaruni AS, Tomsig JL, Okabe K, Lo RH, Cameron Coleman G, Columbus L, Yan Z, Saucerman JJ, Smith JS, Holmes JW, Lynch KR, Ravichandran KS, Uchiyama S, Santos WL, Rogers GW, Okusa MD, Bayliss DA, Hoehn KL. Identification of a novel mitochondrial uncoupler that does not depolarize the plasma membrane. Mol Metab 2013; 3:114-23. [PMID: 24634817 DOI: 10.1016/j.molmet.2013.11.005] [Citation(s) in RCA: 157] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 11/15/2013] [Accepted: 11/15/2013] [Indexed: 11/29/2022] Open
Abstract
Dysregulation of oxidative phosphorylation is associated with increased mitochondrial reactive oxygen species production and some of the most prevalent human diseases including obesity, cancer, diabetes, neurodegeneration, and heart disease. Chemical 'mitochondrial uncouplers' are lipophilic weak acids that transport protons into the mitochondrial matrix via a pathway that is independent of ATP synthase, thereby uncoupling nutrient oxidation from ATP production. Mitochondrial uncouplers also lessen the proton motive force across the mitochondrial inner membrane and thereby increase the rate of mitochondrial respiration while decreasing production of reactive oxygen species. Thus, mitochondrial uncouplers are valuable chemical tools that enable the measurement of maximal mitochondrial respiration and they have been used therapeutically to decrease mitochondrial reactive oxygen species production. However, the most widely used protonophore uncouplers such as carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP) and 2,4-dinitrophenol have off-target activity at other membranes that lead to a range of undesired effects including plasma membrane depolarization, mitochondrial inhibition, and cytotoxicity. These unwanted properties interfere with the measurement of mitochondrial function and result in a narrow therapeutic index that limits their usefulness in the clinic. To identify new mitochondrial uncouplers that lack off-target activity at the plasma membrane we screened a small molecule chemical library. Herein we report the identification and validation of a novel mitochondrial protonophore uncoupler (2-fluorophenyl){6-[(2-fluorophenyl)amino](1,2,5-oxadiazolo[3,4-e]pyrazin-5-yl)}amine, named BAM15, that does not depolarize the plasma membrane. Compared to FCCP, an uncoupler of equal potency, BAM15 treatment of cultured cells stimulates a higher maximum rate of mitochondrial respiration and is less cytotoxic. Furthermore, BAM15 is bioactive in vivo and dose-dependently protects mice from acute renal ischemic-reperfusion injury. From a technical standpoint, BAM15 represents an effective new tool that allows the study of mitochondrial function in the absence of off-target effects that can confound data interpretation. From a therapeutic perspective, BAM15-mediated protection from ischemia-reperfusion injury and its reduced toxicity will hopefully reignite interest in pharmacological uncoupling for the treatment of the myriad of diseases that are associated with altered mitochondrial function.
Collapse
Key Words
- ANT, adenine nucleotide translocase
- Bioenergetics
- CCCP
- DNP
- ECAR, extracellular acidification rate
- FCCP
- FCCP, carbonyl cyanide p-trifluoromethoxyphenylhydrazone
- Ischemia
- Mitochondria
- OCR, oxygen consumption rate
- ROS, reactive oxygen species
- TCA cycle, tricarboxylic acid cycle
- TMPD, N,N,N′,N′-tetramethyl-p-phenylenediamine dihydrochloride
- TMRM, tetramethylrhodamine
Collapse
Affiliation(s)
- Brandon M Kenwood
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Janelle L Weaver
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Amandeep Bajwa
- Department of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Ivan K Poon
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA 22908, USA
| | - Frances L Byrne
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Beverley A Murrow
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Joseph A Calderone
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, VA 24061, USA
| | - Liping Huang
- Department of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Ajit S Divakaruni
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA
| | - Jose L Tomsig
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | | | - Ryan H Lo
- Department of Chemistry, University of Virginia, Charlottesville, VA 22908, USA
| | - G Cameron Coleman
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Linda Columbus
- Department of Chemistry, University of Virginia, Charlottesville, VA 22908, USA
| | - Zhen Yan
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA ; Department of Medicine, University of Virginia, Charlottesville, VA 22908, USA ; Department of Cardiovascular Research Center, University of Virginia, Charlottesville, VA 22908, USA
| | - Jeffrey J Saucerman
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA ; Department of Cardiovascular Research Center, University of Virginia, Charlottesville, VA 22908, USA
| | - Jeffrey S Smith
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
| | - Jeffrey W Holmes
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA ; Department of Cardiovascular Research Center, University of Virginia, Charlottesville, VA 22908, USA
| | - Kevin R Lynch
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Kodi S Ravichandran
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA 22908, USA
| | | | - Webster L Santos
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, VA 24061, USA
| | | | - Mark D Okusa
- Department of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Douglas A Bayliss
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Kyle L Hoehn
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA ; Department of Medicine, University of Virginia, Charlottesville, VA 22908, USA ; Department of Cardiovascular Research Center, University of Virginia, Charlottesville, VA 22908, USA ; Emily Couric Clinical Cancer Center, University of Virginia, Charlottesville, VA 22908, USA
| |
Collapse
|
46
|
Gómez-Sánchez R, Gegg ME, Bravo-San Pedro JM, Niso-Santano M, Alvarez-Erviti L, Pizarro-Estrella E, Gutiérrez-Martín Y, Alvarez-Barrientos A, Fuentes JM, González-Polo RA, Schapira AHV. Mitochondrial impairment increases FL-PINK1 levels by calcium-dependent gene expression. Neurobiol Dis 2013; 62:426-40. [PMID: 24184327 PMCID: PMC3898697 DOI: 10.1016/j.nbd.2013.10.021] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 10/06/2013] [Accepted: 10/22/2013] [Indexed: 01/02/2023] Open
Abstract
Mutations of the PTEN-induced kinase 1 (PINK1) gene are a cause of autosomal recessive Parkinson's disease (PD). This gene encodes a mitochondrial serine/threonine kinase, which is partly localized to mitochondria, and has been shown to play a role in protecting neuronal cells from oxidative stress and cell death, perhaps related to its role in mitochondrial dynamics and mitophagy. In this study, we report that increased mitochondrial PINK1 levels observed in human neuroblastoma SH-SY5Y cells after carbonyl cyanide m-chlorophelyhydrazone (CCCP) treatment were due to de novo protein synthesis, and not just increased stabilization of full length PINK1 (FL-PINK1). PINK1 mRNA levels were significantly increased by 4-fold after 24h. FL-PINK1 protein levels at this time point were significantly higher than vehicle-treated, or cells treated with CCCP for 3h, despite mitochondrial content being decreased by 29%. We have also shown that CCCP dissipated the mitochondrial membrane potential (Δψm) and induced entry of extracellular calcium through L/N-type calcium channels. The calcium chelating agent BAPTA-AM impaired the CCCP-induced PINK1 mRNA and protein expression. Furthermore, CCCP treatment activated the transcription factor c-Fos in a calcium-dependent manner. These data indicate that PINK1 expression is significantly increased upon CCCP-induced mitophagy in a calcium-dependent manner. This increase in expression continues after peak Parkin mitochondrial translocation, suggesting a role for PINK1 in mitophagy that is downstream of ubiquitination of mitochondrial substrates. This sensitivity to intracellular calcium levels supports the hypothesis that PINK1 may also play a role in cellular calcium homeostasis and neuroprotection.
Collapse
Affiliation(s)
- Rubén Gómez-Sánchez
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Departamento de Bioquímica y Biología Molecular y Genética, Universidad de Extremadura, F. Enfermería y Terapia Ocupacional, 10003 Cáceres, Spain
| | - Matthew E Gegg
- Department of Clinical Neurosciences, Institute of Neurology, University College London, London NW3 2PF, UK
| | - José M Bravo-San Pedro
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Departamento de Bioquímica y Biología Molecular y Genética, Universidad de Extremadura, F. Enfermería y Terapia Ocupacional, 10003 Cáceres, Spain; INSERM, U848, Institut Gustave Roussy, Université Paris Sud, Paris 11, F-94805 Villejuif, France
| | - Mireia Niso-Santano
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Departamento de Bioquímica y Biología Molecular y Genética, Universidad de Extremadura, F. Enfermería y Terapia Ocupacional, 10003 Cáceres, Spain; INSERM, U848, Institut Gustave Roussy, Université Paris Sud, Paris 11, F-94805 Villejuif, France
| | - Lydia Alvarez-Erviti
- Department of Clinical Neurosciences, Institute of Neurology, University College London, London NW3 2PF, UK
| | - Elisa Pizarro-Estrella
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Departamento de Bioquímica y Biología Molecular y Genética, Universidad de Extremadura, F. Enfermería y Terapia Ocupacional, 10003 Cáceres, Spain
| | - Yolanda Gutiérrez-Martín
- Servicio de Técnicas Aplicadas a las Biociencias, Universidad de Extremadura, 06071 Badajoz, Spain
| | | | - José M Fuentes
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Departamento de Bioquímica y Biología Molecular y Genética, Universidad de Extremadura, F. Enfermería y Terapia Ocupacional, 10003 Cáceres, Spain.
| | - Rosa Ana González-Polo
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Departamento de Bioquímica y Biología Molecular y Genética, Universidad de Extremadura, F. Enfermería y Terapia Ocupacional, 10003 Cáceres, Spain.
| | - Anthony H V Schapira
- Department of Clinical Neurosciences, Institute of Neurology, University College London, London NW3 2PF, UK
| |
Collapse
|
47
|
Turner PJ, Buckler KJ. Oxygen and mitochondrial inhibitors modulate both monomeric and heteromeric TASK-1 and TASK-3 channels in mouse carotid body type-1 cells. J Physiol 2013; 591:5977-98. [PMID: 24042502 DOI: 10.1113/jphysiol.2013.262022] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
In rat arterial chemoreceptors, background potassium channels play an important role in maintaining resting membrane potential and promoting depolarization and excitation in response to hypoxia or acidosis. It has been suggested that these channels are a heterodimer of TASK-1 and TASK-3 based on their similarity to heterologously expressed TASK-1/3 fusion proteins. In this study, we sought to confirm the identity of these channels through germline ablation of Task-1 (Kcnk3) and Task-3 (Kcnk9) in mice. Background K-channels were abundant in carotid body type-1 cells from wild-type mice and comparable to those previously described in rat type-1 cells with a main conductance state of 33 pS. This channel was absent from both Task-1(-/-) and Task-3(-/-) cells. In its place we observed a larger (38 pS) K(+)-channel in Task-1(-/-) cells and a smaller (18 pS) K(+)-channel in Task-3(-/-) cells. None of these channels were observed in Task-1(-/-)/Task-3(-/-) double knock-out mice. We therefore conclude that the predominant background K-channel in wild-type mice is a TASK-1/TASK-3 heterodimer, whereas that in Task-1(-/-) mice is TASK-3 and, conversely, that in Task-3(-/-) mice is TASK-1. All three forms of TASK channel in type-1 cells were inhibited by hypoxia, cyanide and the uncoupler FCCP, but the greatest sensitivity was seen in TASK-1 and TASK-1/TASK-3 channels. In summary, the background K-channel in type-1 cells is predominantly a TASK-1/TASK-3 heterodimer. Although both TASK-1 and TASK-3 are able to couple to the oxygen and metabolism sensing pathways present in type-1 cells, channels containing TASK-1 appear to be more sensitive.
Collapse
Affiliation(s)
- Philip J Turner
- K. J. Buckler: Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford OX1 3PT, UK.
| | | |
Collapse
|
48
|
da Silva Júnior ED, de Souza BP, Rodrigues JQD, Caricati-Neto A, Jurkiewicz A, Jurkiewicz NH. Functional characterization of acetylcholine receptors and calcium signaling in rat testicular capsule contraction. Eur J Pharmacol 2013; 714:405-13. [PMID: 23872374 DOI: 10.1016/j.ejphar.2013.07.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 07/01/2013] [Accepted: 07/04/2013] [Indexed: 11/24/2022]
Abstract
The motor activity of mammalian testicular capsule (TC) contributes to male fertility and infertility, but the acetylcholine receptors related to the contractions induced by cholinergic drugs are poorly known. Indeed to characterize the acetylcholine receptors and cellular signaling by Ca(2+) involved in TC motor activity of rats, the potency of agonists (pD₂) and antagonists (pA₂) of acetylcholine receptors, and effects of Ca(2+) cellular transport blockers on the cholinergic contractions were evaluated. pD₂ values of acetylcholine (5.98) were ten-fold higher than that of carbachol (4.99). Efficacy (Emax) of acetylcholine and carbachol to induce contractions corresponded to 95% and 97% of Emax for KCl, but Emax for nicotine was very low (8% of Emax for KCl). Further, physostigmine did not affect the acetylcholine potency. Contractions induced by acetylcholine or carbachol were antagonized by muscarinic but not nicotinic antagonist. The order of pA₂ values obtained for muscarinic antagonists, namely atropine>4-DAMP>AF-DX116>pirenzepine, corresponded to a typical profile of M3 receptors. Contractions induced by acetylcholine or carbachol were inhibited by blockers of Ca(2+) influx through voltage-dependent calcium channels (nifedipine and Ni(2+)), Ca(2+) reuptake by sarco-endoplasmic reticulum (cyclopiazonic acid) and mitochondria (FCCP). The protein kinase C (PKC) inhibitor chelerythrine only affected the acetylcholine-induced contraction. These results suggest that TC motor activity of rats are mediated mainly by M₃ receptors followed by the increase of cytosolic Ca(2+) concentration regulated by voltage-dependent calcium channels, sarco-endoplasmic reticulum and mitochondria. Furthermore, the differential effects of chelerythrine in the acetylcholine or carbachol-induced contractions are discussed.
Collapse
|
49
|
Buckler KJ, Turner PJ. Oxygen sensitivity of mitochondrial function in rat arterial chemoreceptor cells. J Physiol 2013; 591:3549-63. [PMID: 23671162 PMCID: PMC3731613 DOI: 10.1113/jphysiol.2013.257741] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The mechanism of oxygen sensing in arterial chemoreceptors is unknown but has often been linked to mitochondrial function. A common criticism of this hypothesis is that mitochondrial function is insensitive to physiological levels of hypoxia. Here we investigate the effects of hypoxia (down to 0.5% O2) on mitochondrial function in neonatal rat type-1 cells. The oxygen sensitivity of mitochondrial [NADH] was assessed by monitoring autofluorescence and increased in hypoxia with a P50 of 15 mm Hg (1 mm Hg = 133.3 Pa) in normal Tyrode or 46 mm Hg in Ca(2+)-free Tyrode. Hypoxia also depolarised mitochondrial membrane potential (m, measured using rhodamine 123) with a P50 of 3.1, 3.3 and 2.8 mm Hg in normal Tyrode, Ca(2+)-free Tyrode and Tyrode containing the Ca(2+) channel antagonist Ni(2+), respectively. In the presence of oligomycin and low carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (FCCP; 75 nm) m is maintained by electron transport working against an artificial proton leak. Under these conditions hypoxia depolarised m/inhibited electron transport with a P50 of 5.4 mm Hg. The effects of hypoxia upon cytochrome oxidase activity were investigated using rotenone, myxothiazol, antimycin A, oligomycin, ascorbate and the electron donor tetramethyl-p-phenylenediamine. Under these conditions m is maintained by complex IV activity alone. Hypoxia inhibited cytochrome oxidase activity (depolarised m) with a P50 of 2.6 mm Hg. In contrast hypoxia had little or no effect upon NADH (P50 = 0.3 mm Hg), electron transport or cytochrome oxidase activity in sympathetic neurons. In summary, type-1 cell mitochondria display extraordinary oxygen sensitivity commensurate with a role in oxygen sensing. The reasons for this highly unusual behaviour are as yet unexplained.
Collapse
Affiliation(s)
- Keith J Buckler
- Department of Physiology, Anatomy & Genetics, Parks Road, Oxford, UK.
| | | |
Collapse
|
50
|
Carroll JL, Kim I. Carotid chemoreceptor "resetting" revisited. Respir Physiol Neurobiol 2012; 185:30-43. [PMID: 22982216 DOI: 10.1016/j.resp.2012.09.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 09/03/2012] [Accepted: 09/06/2012] [Indexed: 12/16/2022]
Abstract
Carotid body (CB) chemoreceptors transduce low arterial O(2) tension into increased action potential activity on the carotid sinus nerves, which contributes to resting ventilatory drive, increased ventilatory drive in response to hypoxia, arousal responses to hypoxia during sleep, upper airway muscle activity, blood pressure control and sympathetic tone. Their sensitivity to O(2) is low in the newborn and increases during the days or weeks after birth to reach adult levels. This postnatal functional maturation of the CB O(2) response has been termed "resetting" and it occurs in every mammalian species studied to date. The O(2) environment appears to play a key role; the fetus develops in a low O(2) environment throughout gestation and initiation of CB "resetting" after birth is modulated by the large increase in arterial oxygen tension occurring at birth. Although numerous studies have reported age-related changes in various components of the O(2) transduction cascade, how the O(2) environment shapes normal CB prenatal development and postnatal "resetting" remains unknown. Viewing CB "resetting" as environment-driven (developmental) phenotypic plasticity raises important mechanistic questions that have received little attention. This review examines what is known (and not known) about mechanisms of CB functional maturation, with a focus on the role of the O(2) environment.
Collapse
Affiliation(s)
- John L Carroll
- Division of Pediatric Pulmonary Medicine, Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, 1 Children's Way, Little Rock, AR 72202, United States.
| | | |
Collapse
|