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Li M, Gasanoff ES. Cationic Proteins Rich in Lysine Residue Trigger Formation of Non-bilayer Lipid Phases in Model and Biological Membranes: Biophysical Methods of Study. J Membr Biol 2023; 256:373-391. [PMID: 37735238 DOI: 10.1007/s00232-023-00292-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 09/05/2023] [Indexed: 09/23/2023]
Abstract
Cationic membrane-active toxins are the most abundant group of proteins in the venom of snakes and insects. Cationic proteins such as cobra venom cytotoxin and bee venom melittin are known for their pharmacological reactions including anticancer and antimicrobial effects which arise from the toxin-induced alteration in the dynamics and structure of plasma membranes and membranes of organelles. It has been established that these cationic toxins trigger the formation of non-bilayer lipid phase transitions in artificial and native mitochondrial membranes. Remarkably, the toxin-induced formation of non-bilayer lipid phase increases at certain conditions mitochondrial ATP synthase activity. This observation opens an intriguing avenue for using cationic toxins in the development of novel drugs for the treatment of cellular energy deficiency caused by aging and diseases. This observation also warrants a thorough investigation of the molecular mechanism(s) of lipid phase polymorphisms triggered by cationic proteins. This article presents a review on the application of powerful biophysical methods such as resonance spectroscopy (31P-, 1H-, 2H-nuclear magnetic resonance, and electron paramagnetic resonance), luminescence, and differential scanning microcalorimetry in studies of non-bilayer lipid phase transitions triggered by cationic proteins in artificial and biological membranes. A phenomenon of the triggered by cationic proteins the non-bilayer lipid phase transitions occurring within 10-2-10-11 s is discussed in the context of potential pharmacological applications of cationic proteins. Next to the ATP dimer is an inverted micelle made of cardiolipin that serves as a vehicle for the transport of H+ ions from the intra-crista space to the matrix. It is proposed that such inverted micelles are triggered by the high density of H+ ions and the cationic proteins rich in lysine residue which compete with the conserved lysine residues of the ATP synthase rotor for binding to cardiolipin in the inner mitochondrial membrane and perturb the bilayer lipid packing of cristae. Phospholipids with a blue polar head represent cardiolipin and those with a red polar head represent other phospholipids found in the crista membrane.
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Affiliation(s)
- Meiyi Li
- STEM Research Centre, Science Department, Chaoyang Kaiwen Academy, Beijing, 100018, China
| | - Edward S Gasanoff
- STEM Research Centre, Science Department, Chaoyang Kaiwen Academy, Beijing, 100018, China.
- Belozersky Institute of Physico-Chemical Biology, M.V. Lomonosov Moscow State University, Moscow, 119991, Russia.
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Nair SC, Munro JT, Mann A, Llinás M, Prigge ST. The mitochondrion of Plasmodium falciparum is required for cellular acetyl-CoA metabolism and protein acetylation. Proc Natl Acad Sci U S A 2023; 120:e2210929120. [PMID: 37068227 PMCID: PMC10151609 DOI: 10.1073/pnas.2210929120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 02/28/2023] [Indexed: 04/19/2023] Open
Abstract
Coenzyme A (CoA) biosynthesis is an excellent target for antimalarial intervention. While most studies have focused on the use of CoA to produce acetyl-CoA in the apicoplast and the cytosol of malaria parasites, mitochondrial acetyl-CoA production is less well understood. In the current study, we performed metabolite-labeling experiments to measure endogenous metabolites in Plasmodium falciparum lines with genetic deletions affecting mitochondrial dehydrogenase activity. Our results show that the mitochondrion is required for cellular acetyl-CoA biosynthesis and identify a synthetic lethal relationship between the two main ketoacid dehydrogenase enzymes. The activity of these enzymes is dependent on the lipoate attachment enzyme LipL2, which is essential for parasite survival solely based on its role in supporting acetyl-CoA metabolism. We also find that acetyl-CoA produced in the mitochondrion is essential for the acetylation of histones and other proteins outside of the mitochondrion. Taken together, our results demonstrate that the mitochondrion is required for cellular acetyl-CoA metabolism and protein acetylation essential for parasite survival.
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Affiliation(s)
- Sethu C. Nair
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD21218
| | - Justin T. Munro
- Department of Chemistry, Pennsylvania State University, University Park, PA16802
- Huck Center for Malaria Research, Pennsylvania State University, University Park, PA16802
| | - Alexis Mann
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD21218
| | - Manuel Llinás
- Department of Chemistry, Pennsylvania State University, University Park, PA16802
- Huck Center for Malaria Research, Pennsylvania State University, University Park, PA16802
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA16802
| | - Sean T. Prigge
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD21218
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Kocherginsky N. Biomimetic Membranes without Proteins but with Aqueous Nanochannels and Facilitated Transport. Minireview. MEMBRANES AND MEMBRANE TECHNOLOGIES 2021. [PMCID: PMC8675542 DOI: 10.1134/s251775162106010x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- N. Kocherginsky
- NEXT-ChemX, Department of Chemistry, University of Illinois, 61801 Urbana, Illinois USA
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4
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Cardiolipin, Non-Bilayer Structures and Mitochondrial Bioenergetics: Relevance to Cardiovascular Disease. Cells 2021; 10:cells10071721. [PMID: 34359891 PMCID: PMC8304834 DOI: 10.3390/cells10071721] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/19/2021] [Accepted: 06/29/2021] [Indexed: 12/23/2022] Open
Abstract
The present review is an attempt to conceptualize a contemporary understanding about the roles that cardiolipin, a mitochondrial specific conical phospholipid, and non-bilayer structures, predominantly found in the inner mitochondrial membrane (IMM), play in mitochondrial bioenergetics. This review outlines the link between changes in mitochondrial cardiolipin concentration and changes in mitochondrial bioenergetics, including changes in the IMM curvature and surface area, cristae density and architecture, efficiency of electron transport chain (ETC), interaction of ETC proteins, oligomerization of respiratory complexes, and mitochondrial ATP production. A relationship between cardiolipin decline in IMM and mitochondrial dysfunction leading to various diseases, including cardiovascular diseases, is thoroughly presented. Particular attention is paid to the targeting of cardiolipin by Szeto–Schiller tetrapeptides, which leads to rejuvenation of important mitochondrial activities in dysfunctional and aging mitochondria. The role of cardiolipin in triggering non-bilayer structures and the functional roles of non-bilayer structures in energy-converting membranes are reviewed. The latest studies on non-bilayer structures induced by cobra venom peptides are examined in model and mitochondrial membranes, including studies on how non-bilayer structures modulate mitochondrial activities. A mechanism by which non-bilayer compartments are formed in the apex of cristae and by which non-bilayer compartments facilitate ATP synthase dimerization and ATP production is also presented.
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5
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Enhancement of acidic lipid analysis by nanoflow ultrahigh performance liquid chromatography–mass spectrometry. Anal Chim Acta 2021; 1166:338573. [DOI: 10.1016/j.aca.2021.338573] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/31/2021] [Accepted: 04/22/2021] [Indexed: 01/11/2023]
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Semenova AA, Samartsev VN, Dubinin MV. The stimulation of succinate-fueled respiration of rat liver mitochondria in state 4 by α,ω-hexadecanedioic acid without induction of proton conductivity of the inner membrane. Intrinsic uncoupling of the bc 1 complex. Biochimie 2021; 181:215-225. [PMID: 33400934 DOI: 10.1016/j.biochi.2020.12.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 12/19/2020] [Accepted: 12/28/2020] [Indexed: 10/22/2022]
Abstract
The paper shows that natural α,ω-dioic acid, α,ω-hexadecanedioic acid (HDA), is able to stimulate the respiration of succinate-fueled rat liver mitochondria in state 4 without induction of proton conductivity of the inner membrane. This effect of HDA is less pronounced in glutamate/malate-fueled mitochondria, as well as in the case of ascorbate/TMPD or ascorbate/ferrocyanide substrate systems, which transfer electrons directly to cytochrome c. It is noted that HDA-induced stimulation of respiration is not associated with damage to the inner membrane in a part of mitochondria and with shunting of electrons through the bc1 complex. Therefore, HDA can be considered as a natural decoupling agent. Specific inhibitors of the bc1 complex (antimycin A and myxothiazole) as well as malonate and dithionitrobenzoate were used in the inhibitory analysis. These and other experiments have shown that during the oxidation of succinate in liver mitochondria, the decoupling effect of HDA is mainly carried out at the level of the bc1 complex. We hypothesized that HDA is capable of promoting the cyclic transport of protons within the bc1 complex and thus switch this complex to the idle mode of operation (intrinsic uncoupling of the bc1 complex). Induction of free respiration in liver mitochondria by HDA at the level of the bc1 complex is considered as one of the "rescue pathways" of hepatocytes in various pathological conditions, accompanied by disorders of carbohydrate and lipid metabolism and increased oxidative stress.
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Affiliation(s)
- Alena A Semenova
- Mari State University, Pl. Lenina 1, Yoshkar-Ola, Mari El, 424001, Russia
| | - Victor N Samartsev
- Mari State University, Pl. Lenina 1, Yoshkar-Ola, Mari El, 424001, Russia
| | - Mikhail V Dubinin
- Mari State University, Pl. Lenina 1, Yoshkar-Ola, Mari El, 424001, Russia.
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Abstract
ATP is required for mammalian cells to remain viable and to perform genetically programmed functions. Maintenance of the ΔG′ATP hydrolysis of −56 kJ/mole is the endpoint of both genetic and metabolic processes required for life. Various anomalies in mitochondrial structure and function prevent maximal ATP synthesis through OxPhos in cancer cells. Little ATP synthesis would occur through glycolysis in cancer cells that express the dimeric form of pyruvate kinase M2. Mitochondrial substrate level phosphorylation (mSLP) in the glutamine-driven glutaminolysis pathway, substantiated by the succinate-CoA ligase reaction in the TCA cycle, can partially compensate for reduced ATP synthesis through both OxPhos and glycolysis. A protracted insufficiency of OxPhos coupled with elevated glycolysis and an auxiliary, fully operational mSLP, would cause a cell to enter its default state of unbridled proliferation with consequent dedifferentiation and apoptotic resistance, i.e., cancer. The simultaneous restriction of glucose and glutamine offers a therapeutic strategy for managing cancer.
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Affiliation(s)
- Thomas N Seyfried
- Biology Department, Boston College, 140 Commonwealth Avenue, Chestnut Hill, MA 02467, USA
| | - Gabriel Arismendi-Morillo
- Electron Microscopy Laboratory, Biological Researches Institute, Faculty of Medicine, University of Zulia, Maracaibo, Venezuela
| | - Purna Mukherjee
- Biology Department, Boston College, 140 Commonwealth Avenue, Chestnut Hill, MA 02467, USA
| | - Christos Chinopoulos
- Department of Medical Biochemistry, Semmelweis University, Budapest, 1094, Hungary
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A Comparative Study of the Action of Protonophore Uncouplers and Decoupling Agents as Inducers of Free Respiration in Mitochondria in States 3 and 4: Theoretical and Experimental Approaches. Cell Biochem Biophys 2020; 78:203-216. [PMID: 32367259 DOI: 10.1007/s12013-020-00914-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 04/17/2020] [Indexed: 02/07/2023]
Abstract
Theoretical and experimental studies have revealed that that in the liver mitochondria an increase in the rate of free respiration in state 3 induced by protonophore uncouplers 2,4-dinitrophenol and сarbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone is equal to or slightly greater than the increase in respiration rate in state 4 induced by these uncouplers. In contrast to these protonophore uncouplers, the decoupler α,ω-tetradecanedioic acid, increasing the rate of respiration in state 4, does not significantly affect the rate of free respiration in state 3. We have proposed quantitative indicators that allow determining the constituent part of the rate of respiration in state 4, associated with the decoupling effect of the uncoupler. Using the example of palmitic acid, we have found out the fundamental possibility of the simultaneous functioning of uncouplers by two mechanisms: as protonophores and as decouplers. The data obtained contradict the delocalized version of Mitchell's chemiosmotic theory, but are in complete agreement with its local version. It can be assumed that the F0F1-ATP synthase and nearby respiratory chain complexes form a local zone of coupled respiration and oxidative ATP synthesis (zones of oxidative phosphorylation). The uncoupler-induced stimulation of mitochondrial free respiration of mitochondria in state 3 is mainly due to the return of protons to the matrix in local zones, where the generation of a proton motive force (Δр) by respiratory chain complexes is associated with various transport processes, but not with ATP synthesis (zones of protonophore uncoupling). In contrast, respiratory stimulation in state 4 by decouplers is realized in local zones of oxidative phosphorylation by switching the respiratory chain complexes to the idle mode of operation in the absence of ATP synthesis.
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Non-bilayer structures in mitochondrial membranes regulate ATP synthase activity. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:586-599. [PMID: 29179995 DOI: 10.1016/j.bbamem.2017.11.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 10/26/2017] [Accepted: 11/22/2017] [Indexed: 01/12/2023]
Abstract
Cardiolipin (CL) is an anionic phospholipid at the inner mitochondrial membrane (IMM) that facilitates the formation of transient non-bilayer (non-lamellar) structures to maintain mitochondrial integrity. CL modulates mitochondrial functions including ATP synthesis. However, the biophysical mechanisms by which CL generates non-lamellar structures and the extent to which these structures contribute to ATP synthesis remain unknown. We hypothesized that CL and ATP synthase facilitate the formation of non-bilayer structures at the IMM to stimulate ATP synthesis. By using 1H NMR and 31P NMR techniques, we observed that increasing the temperature (8°C to 37°C), lowering the pH (3.0), or incubating intact mitochondria with CTII - an IMM-targeted toxin that increases the formation of immobilized non-bilayer structures - elevated the formation of non-bilayer structures to stimulate ATP synthesis. The F0 sector of the ATP synthase complex can facilitate the formation of non-bilayer structures as incubating model membranes enriched with IMM-specific phospholipids with exogenous DCCD-binding protein of the F0 sector (DCCD-BPF) elevated the formation of immobilized non-bilayer structures to a similar manner as CTII. Native PAGE assays revealed that CL, but not other anionic phospholipids, specifically binds to DCCD-BPF to promote the formation of stable lipid-protein complexes. Mechanistically, molecular docking studies identified two lipid binding sites for CL in DCCD-BPF. We propose a new model of ATP synthase regulation in which CL mediates the formation of non-bilayer structures that serve to cluster protons and ATP synthase complexes as a mechanism to enhance proton translocation to the F0 sector, and thereby increase ATP synthesis.
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10
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Javadov S, Chapa-Dubocq X, Makarov V. Different approaches to modeling analysis of mitochondrial swelling. Mitochondrion 2017; 38:58-70. [PMID: 28802667 DOI: 10.1016/j.mito.2017.08.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 07/21/2017] [Accepted: 08/08/2017] [Indexed: 12/11/2022]
Abstract
Mitochondria are critical players involved in both cell life and death through multiple pathways. Structural integrity, metabolism and function of mitochondria are regulated by matrix volume due to physiological changes of ion homeostasis in cellular cytoplasm and mitochondria. Ca2+ and K+ presumably play a critical role in physiological and pathological swelling of mitochondria when increased uptake (influx)/decreased release (efflux) of these ions enhances osmotic pressure accompanied by high water accumulation in the matrix. Changes in the matrix volume in the physiological range have a stimulatory effect on electron transfer chain and oxidative phosphorylation to satisfy metabolic requirements of the cell. However, excessive matrix swelling associated with the sustained opening of mitochondrial permeability transition pores (PTP) and other PTP-independent mechanisms compromises mitochondrial function and integrity leading to cell death. The mechanisms of transition from reversible (physiological) to irreversible (pathological) swelling of mitochondria remain unknown. Mitochondrial swelling is involved in the pathogenesis of many human diseases such as neurodegenerative and cardiovascular diseases. Therefore, modeling analysis of the swelling process is important for understanding the mechanisms of cell dysfunction. This review attempts to describe the role of mitochondrial swelling in cell life and death and the main mechanisms involved in the maintenance of ion homeostasis and swelling. The review also summarizes and discusses different kinetic models and approaches that can be useful for the development of new models for better simulation and prediction of in vivo mitochondrial swelling.
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Affiliation(s)
- Sabzali Javadov
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, PR, USA.
| | - Xavier Chapa-Dubocq
- Department of Physiology, School of Medicine, University of Puerto Rico, San Juan, PR, USA
| | - Vladimir Makarov
- Department of Physics, Rio Piedras Campus, University of Puerto Rico, San Juan, PR, USA
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Kellermann MY, Yoshinaga MY, Valentine RC, Wörmer L, Valentine DL. Important roles for membrane lipids in haloarchaeal bioenergetics. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2940-2956. [PMID: 27565574 DOI: 10.1016/j.bbamem.2016.08.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Revised: 08/11/2016] [Accepted: 08/19/2016] [Indexed: 10/21/2022]
Abstract
Recent advances in lipidomic analysis in combination with various physiological experiments set the stage for deciphering the structure-function of haloarchaeal membrane lipids. Here we focused primarily on changes in lipid composition of Haloferax volcanii, but also performed a comparative analysis with four other haloarchaeal species (Halobacterium salinarum, Halorubrum lacusprofundi, Halorubrum sodomense and Haloplanus natans) all representing distinctive cell morphologies and behaviors (i.e., rod shape vs. pleomorphic behavior). Common to all five haloarchaea, our data reveal an extraordinary high level of menaquinone, reaching up to 72% of the total lipids. This ubiquity suggests that menaquinones may function beyond their ordinary role as electron and proton transporter, acting simultaneously as ion permeability barriers and as powerful shield against oxidative stress. In addition, we aimed at understanding the role of cations interacting with the characteristic negatively charged surface of haloarchaeal membranes. We propose for instance that by bridging the negative charges of adjacent anionic phospholipids, Mg2+ acts as surrogate for cardiolipin, a molecule that is known to control curvature stress of membranes. This study further provides a bioenergetic perspective as to how haloarchaea evolved following oxygenation of Earth's atmosphere. The success of the aerobic lifestyle of haloarchaea includes multiple membrane-based strategies that successfully balance the need for a robust bilayer structure with the need for high rates of electron transport - collectively representing the molecular basis to inhabit hypersaline water bodies around the planet.
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Affiliation(s)
- Matthias Y Kellermann
- Department of Earth Science and Marine Science Institute, University of California, Santa Barbara, CA 93106, USA.
| | - Marcos Y Yoshinaga
- MARUM Center for Marine Environmental Sciences and Department of Geosciences, University of Bremen, Leobener Strasse, D-28359 Bremen, Germany
| | | | - Lars Wörmer
- MARUM Center for Marine Environmental Sciences and Department of Geosciences, University of Bremen, Leobener Strasse, D-28359 Bremen, Germany
| | - David L Valentine
- Department of Earth Science and Marine Science Institute, University of California, Santa Barbara, CA 93106, USA.
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12
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Yoshinaga MY, Kellermann MY, Valentine DL, Valentine RC. Phospholipids and glycolipids mediate proton containment and circulation along the surface of energy-transducing membranes. Prog Lipid Res 2016; 64:1-15. [PMID: 27448687 DOI: 10.1016/j.plipres.2016.07.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 05/29/2016] [Accepted: 07/13/2016] [Indexed: 01/06/2023]
Abstract
Proton bioenergetics provides the energy for growth and survival of most organisms in the biosphere ranging from unicellular marine phytoplankton to humans. Chloroplasts harvest light and generate a proton electrochemical gradient (proton motive force) that drives the production of ATP needed for carbon dioxide fixation and plant growth. Mitochondria, bacteria and archaea generate proton motive force to energize growth and other physiologies. Energy transducing membranes are at the heart of proton bioenergetics and are responsible for catalyzing the conversion of energy held in high-energy electrons→electron transport chain→proton motive force→ATP. Whereas the electron transport chain is understood in great detail there are major gaps in understanding mechanisms of proton transfer or circulation during proton bioenergetics. This paper is built on the proposition that phospho- and glyco-glycerolipids form proton transport circuitry at the membrane's surface. By this proposition, an emergent membrane property, termed the hyducton, confines active/unbound protons or hydronium ions to a region of low volume close to the membrane surface. In turn, a von Grotthuß mechanism rapidly moves proton substrate in accordance with nano-electrochemical poles on the membrane surface created by powerful proton pumps such as ATP synthase.
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Affiliation(s)
- Marcos Y Yoshinaga
- University of Bremen, MARUM - Center for Marine and Environmental Sciences, Germany.
| | - Matthias Y Kellermann
- University of California Santa Barbara - Department of Earth Science and Marine Science Institute, USA
| | - David L Valentine
- University of California Santa Barbara - Department of Earth Science and Marine Science Institute, USA
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Gasanov SE, Kim AA, Dagda RK. The Possible Role of Nonbilayer Structures in Regulating ATP Synthase Activity in Mitochondrial Membranes. Biophysics (Nagoya-shi) 2016; 61:596-600. [PMID: 28065984 PMCID: PMC5215001 DOI: 10.1134/s0006350916040084] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The effects of temperature and of the membrane-active protein CTII on the formation of nonbilayer structures in mitochondrial membranes were studied by 31P-NMR. Increasing the temperature of isolated mitochondrial fractions correlated with an increase in ATP synthase activity and the formation of nonbilayer packed phospholipids with immobilized molecular mobility. Computer modeling was employed for analyzing the interaction of mitochondrial membrane phospholipids with the molecular surface of CTII, which behaves like a dicyclohexylcarbodiimide-binding protein (DCCD-BP) of the F0 group in a lipid phase. Overall, our studies suggest that proton permeability toroidal pores formed in mitochondrial membranes consist of immobilized nonbilayer-packed phospholipids formed via interactions with DCCD-BP. Our studies support the existence of a proton transport along a concentration gradient mediated via transit toroidal permeability pores which induce conformational changes necessary for mediating the catalytic activity of ATP synthase in the subunits of the F0-F1 complex.
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Affiliation(s)
- S E Gasanov
- Moscow State University Branch, 22a A. Timur Avenue, Tashkent, 100060 Uzbekistan
| | - A A Kim
- Moscow State University Branch, 22a A. Timur Avenue, Tashkent, 100060 Uzbekistan
| | - R K Dagda
- Department of Pharmacology, University of Nevada, Reno School of Medicine,1664 North Virginia St., Reno, Nevada, 89557 United States
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Detchanamurthy S, Gostomski PA. Studies on the influence of different metabolic uncouplers on the biodegradation of toluene in a differential biofilter reactor. BIOTECHNOL BIOPROC E 2015. [DOI: 10.1007/s12257-014-1228-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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15
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Abstract
Nature supports multifaceted forms of life. Despite the variety and complexity of these forms, motility remains the epicenter of life. The applicable laws of physics change upon going from macroscales to microscales and nanoscales, which are characterized by low Reynolds number (Re). We discuss motion at low Re in natural and synthetic systems, along with various propulsion mechanisms, including electrophoresis, electrolyte diffusiophoresis, and nonelectrolyte diffusiophoresis. We also describe the newly uncovered phenomena of motility in non-ATP-driven self-powered enzymes and the directional movement of these enzymes in response to substrate gradients. These enzymes can also be immobilized to function as fluid pumps in response to the presence of their substrates. Finally, we review emergent collective behavior arising from interacting motile species, and we discuss the possible biomedical applications of the synthetic nanobots and microbots.
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Affiliation(s)
| | | | - Peter J. Butler
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802;,
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O-Uchi J, Ryu SY, Jhun BS, Hurst S, Sheu SS. Mitochondrial ion channels/transporters as sensors and regulators of cellular redox signaling. Antioxid Redox Signal 2014; 21:987-1006. [PMID: 24180309 PMCID: PMC4116125 DOI: 10.1089/ars.2013.5681] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
SIGNIFICANCE Mitochondrial ion channels/transporters and the electron transport chain (ETC) serve as key sensors and regulators for cellular redox signaling, the production of reactive oxygen species (ROS) and nitrogen species (RNS) in mitochondria, and balancing cell survival and death. Although the functional and pharmacological characteristics of mitochondrial ion transport mechanisms have been extensively studied for several decades, the majority of the molecular identities that are responsible for these channels/transporters have remained a mystery until very recently. RECENT ADVANCES Recent breakthrough studies uncovered the molecular identities of the diverse array of major mitochondrial ion channels/transporters, including the mitochondrial Ca2+ uniporter pore, mitochondrial permeability transition pore, and mitochondrial ATP-sensitive K+ channel. This new information enables us to form detailed molecular and functional characterizations of mitochondrial ion channels/transporters and their roles in mitochondrial redox signaling. CRITICAL ISSUES Redox-mediated post-translational modifications of mitochondrial ion channels/transporters and ETC serve as key mechanisms for the spatiotemporal control of mitochondrial ROS/RNS generation. FUTURE DIRECTIONS Identification of detailed molecular mechanisms for redox-mediated regulation of mitochondrial ion channels will enable us to find novel therapeutic targets for many diseases that are associated with cellular redox signaling and mitochondrial ion channels/transporters.
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Affiliation(s)
- Jin O-Uchi
- 1 Department of Medicine, Center for Translational Medicine, Jefferson Medical College, Thomas Jefferson University , Philadelphia, Pennsylvania
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17
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Song DH, Park J, Philbert MA, Sastry AM, Lu W. Effects of local pH on the formation and regulation of cristae morphologies. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 90:022702. [PMID: 25215753 DOI: 10.1103/physreve.90.022702] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Indexed: 06/03/2023]
Abstract
Cristae, folded subcompartments of the inner mitochondrial membrane (IMM), have complex and dynamic morphologies. Since cristae are the major site of adenosine triphosphate synthesis, morphological changes of cristae have been studied in relation to functional states of mitochondria. In this sense, investigating the functional and structural significance of cristae may be critical for understanding progressive mitochondrial dysfunction. However, the detailed mechanisms of the formation and regulation of these cristae structures have not been fully elucidated. Among the hypotheses concerning the regulation of cristae morphologies, we exclusively investigate the effects of the local pH gradient on the cristae morphologies by using a numerical model. An area-difference induced curvature of the membrane is modeled as a function of local pH. This curvature is then applied to the finite element model of a closed lipid bilayer in order to find the energetically favorable membrane configuration. From this study, we substantiate the hypothesis that a tubular crista structure can be formed and regulated by the local pH gradient. Through the simulations with various initial conditions, we further demonstrate that the diameter of a crista is mainly determined by the local pH gradient, and the energetically favorable direction of crista growth is perpendicular to the longitudinal axis of a mitochondrion. Finally, the simulation results at the mitochondrial scale suggest that the cristae membrane may have a lower local pH value and/or a higher cardiolipin composition than the other parts of the IMM.
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Affiliation(s)
- Dong Hoon Song
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Jonghyun Park
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Martin A Philbert
- School of Public Health, University of Michigan, Ann Arbor, Michigan 48109, USA
| | | | - Wei Lu
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
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Seyfried TN, Flores RE, Poff AM, D'Agostino DP. Cancer as a metabolic disease: implications for novel therapeutics. Carcinogenesis 2013; 35:515-27. [PMID: 24343361 PMCID: PMC3941741 DOI: 10.1093/carcin/bgt480] [Citation(s) in RCA: 303] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Emerging evidence indicates that cancer is primarily a metabolic disease involving disturbances in energy production through respiration and fermentation. The genomic instability observed in tumor cells and all other recognized hallmarks of cancer are considered downstream epiphenomena of the initial disturbance of cellular energy metabolism. The disturbances in tumor cell energy metabolism can be linked to abnormalities in the structure and function of the mitochondria. When viewed as a mitochondrial metabolic disease, the evolutionary theory of Lamarck can better explain cancer progression than can the evolutionary theory of Darwin. Cancer growth and progression can be managed following a whole body transition from fermentable metabolites, primarily glucose and glutamine, to respiratory metabolites, primarily ketone bodies. As each individual is a unique metabolic entity, personalization of metabolic therapy as a broad-based cancer treatment strategy will require fine-tuning to match the therapy to an individual’s unique physiology.
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Affiliation(s)
- Thomas N Seyfried
- Biology Department, Boston College, Chestnut Hill, MA 02467, USA and
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Song DH, Park J, Maurer LL, Lu W, Philbert MA, Sastry AM. Biophysical significance of the inner mitochondrial membrane structure on the electrochemical potential of mitochondria. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 88:062723. [PMID: 24483502 PMCID: PMC4315510 DOI: 10.1103/physreve.88.062723] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Indexed: 05/29/2023]
Abstract
The available literature supports the hypothesis that the morphology of the inner mitochondrial membrane is regulated by different energy states, that the three-dimensional morphology of cristae is dynamic, and that both are related to biochemical function. Examination of the correlation between the inner mitochondrial membrane (IMM) structure and mitochondrial energetic function is critical to an understanding of the links between mesoscale morphology and function in progressive mitochondrial dysfunction such as aging, neurodegeneration, and disease. To investigate this relationship, we develop a model to examine the effects of three-dimensional IMM morphology on the electrochemical potential of mitochondria. The two-dimensional axisymmetric finite element method is used to simulate mitochondrial electric potential and proton concentration distribution. This simulation model demonstrates that the proton motive force (Δp) produced on the membranes of cristae can be higher than that on the inner boundary membrane. The model also shows that high proton concentration in cristae can be induced by the morphology-dependent electric potential gradient along the outer side of the IMM. Furthermore, simulation results show that a high Δp is induced by the large surface-to-volume ratio of an individual crista, whereas a high capacity for ATP synthesis can primarily be achieved by increasing the surface area of an individual crista. The mathematical model presented here provides compelling support for the idea that morphology at the mesoscale is a significant driver of mitochondrial function.
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Affiliation(s)
- Dong Hoon Song
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Jonghyun Park
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Laura L Maurer
- Toxicology Program, School of Public Health, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Wei Lu
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Martin A Philbert
- Toxicology Program, School of Public Health, University of Michigan, Ann Arbor, Michigan 48109, USA
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Sengupta S, Ibele ME, Sen A. Fantastic Voyage: Designing Self‐Powered Nanorobots. Angew Chem Int Ed Engl 2012; 51:8434-45. [DOI: 10.1002/anie.201202044] [Citation(s) in RCA: 280] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Revised: 05/04/2012] [Indexed: 01/01/2023]
Affiliation(s)
- Samudra Sengupta
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802 (USA) http://research.chem.psu.edu/axsgroup
| | - Michael E. Ibele
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802 (USA) http://research.chem.psu.edu/axsgroup
| | - Ayusman Sen
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802 (USA) http://research.chem.psu.edu/axsgroup
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Sengupta S, Ibele ME, Sen A. Die phantastische Reise: Nanoroboter mit Eigenantrieb. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201202044] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Samudra Sengupta
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802 (USA) http://research.chem.psu.edu/axsgroup
| | - Michael E. Ibele
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802 (USA) http://research.chem.psu.edu/axsgroup
| | - Ayusman Sen
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802 (USA) http://research.chem.psu.edu/axsgroup
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Haruta M, Sussman MR. The effect of a genetically reduced plasma membrane protonmotive force on vegetative growth of Arabidopsis. PLANT PHYSIOLOGY 2012; 158:1158-71. [PMID: 22214817 PMCID: PMC3291248 DOI: 10.1104/pp.111.189167] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Accepted: 12/28/2011] [Indexed: 05/19/2023]
Abstract
The plasma membrane proton gradient is an essential feature of plant cells. In Arabidopsis (Arabidopsis thaliana), this gradient is generated by the plasma membrane proton pump encoded by a family of 11 genes (abbreviated as AHA, for Arabidopsis H(+)-ATPase), of which AHA1 and AHA2 are the two most predominantly expressed in seedlings and adult plants. Although double knockdown mutant plants containing T-DNA insertions in both genes are embryonic lethal, under ideal laboratory growth conditions, single knockdown mutant plants with a 50% reduction in proton pump concentration complete their life cycle without any observable growth alteration. However, when grown under conditions that induce stress on the plasma membrane protonmotive force (PMF), such as high external potassium to reduce the electrical gradient or high external pH to reduce the proton chemical gradient, aha2 mutant plants show a growth retardation compared with wild-type plants. In this report, we describe the results of studies that examine in greater detail AHA2's specific role in maintaining the PMF during seedling growth. By comparing the wild type and aha2 mutants, we have measured the effects of a reduced PMF on root and hypocotyl growth, ATP-induced skewed root growth, and rapid cytoplasmic calcium spiking. In addition, genome-wide gene expression profiling revealed the up-regulation of potassium transporters in aha2 mutants, indicating, as predicted, a close link between the PMF and potassium uptake at the plasma membrane. Overall, this characterization of aha2 mutants provides an experimental and theoretical framework for investigating growth and signaling processes that are mediated by PMF-coupled energetics at the cell membrane.
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Cardiolipin content in mitochondria from cultured skin fibroblasts harboring mutations in the mitochondrial ATP6 gene. J Bioenerg Biomembr 2011; 43:683-90. [PMID: 21993659 DOI: 10.1007/s10863-011-9387-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Accepted: 09/13/2011] [Indexed: 12/16/2022]
Abstract
The role of phospholipids in normal assembly and organization of the membrane proteins has been well documented. Cardiolipin, a unique tetra-acyl phospholipid localized in the inner mitochondrial membrane, is implicated in the stability of many inner-membrane protein complexes. Loss of cardiolipin content, alterations in its acyl chain composition and/or cardiolipin peroxidation have been associated with dysfunction in multiple tissues in a variety of pathological conditions. The aim of this study was to analyze the phospholipid composition of the mitochondrial membrane in the four most frequent mutations in the ATP6 gene: L156R, L217R, L156P and L217P but, more importantly, to investigate the possible changes in the cardiolipin profile. Mitochondrial membranes from fibroblasts with mutations at codon 217 of the ATP6 gene, showed a different cardiolipin content compared to controls. Conversely, results similar to controls were obtained for mutations at codon 156. These findings may be attributed to differences in the biosynthesis and remodeling of cardiolipin at the level of the inner mitochondrial transmembrane related to some mutations of the ATP6 gene.
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Seyfried TN, Kiebish MA, Marsh J, Shelton LM, Huysentruyt LC, Mukherjee P. Metabolic management of brain cancer. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1807:577-94. [PMID: 20804725 DOI: 10.1016/j.bbabio.2010.08.009] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Revised: 08/11/2010] [Accepted: 08/15/2010] [Indexed: 12/29/2022]
Abstract
Malignant brain tumors are a significant health problem in children and adults. Conventional therapeutic approaches have been largely unsuccessful in providing long-term management. As primarily a metabolic disease, malignant brain cancer can be managed through changes in metabolic environment. In contrast to normal neurons and glia, which readily transition to ketone bodies (β-hydroxybutyrate) for energy under reduced glucose, malignant brain tumors are strongly dependent on glycolysis for energy. The transition from glucose to ketone bodies as a major energy source is an evolutionary conserved adaptation to food deprivation that permits the survival of normal cells during extreme shifts in nutritional environment. Only those cells with a flexible genome and normal mitochondria can effectively transition from one energy state to another. Mutations restrict genomic and metabolic flexibility thus making tumor cells more vulnerable to energy stress than normal cells. We propose an alternative approach to brain cancer management that exploits the metabolic flexibility of normal cells at the expense of the genetically defective and metabolically challenged tumor cells. This approach to brain cancer management is supported from recent studies in mice and humans treated with calorie restriction and the ketogenic diet. Issues of implementation and use protocols are presented for the metabolic management of brain cancer.
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Dahlberg M, Marini A, Mennucci B, Maliniak A. Quantum Chemical Modeling of the Cardiolipin Headgroup. J Phys Chem A 2010; 114:4375-87. [DOI: 10.1021/jp9110019] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Martin Dahlberg
- Division of Physical Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden, and Department of Chemistry, University of Pisa, Via Risorgimento 35, 56126 Pisa, Italy
| | - Alberto Marini
- Division of Physical Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden, and Department of Chemistry, University of Pisa, Via Risorgimento 35, 56126 Pisa, Italy
| | - Benedetta Mennucci
- Division of Physical Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden, and Department of Chemistry, University of Pisa, Via Risorgimento 35, 56126 Pisa, Italy
| | - Arnold Maliniak
- Division of Physical Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden, and Department of Chemistry, University of Pisa, Via Risorgimento 35, 56126 Pisa, Italy
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Seyfried TN, Shelton LM. Cancer as a metabolic disease. Nutr Metab (Lond) 2010; 7:7. [PMID: 20181022 PMCID: PMC2845135 DOI: 10.1186/1743-7075-7-7] [Citation(s) in RCA: 382] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2009] [Accepted: 01/27/2010] [Indexed: 01/08/2023] Open
Abstract
Emerging evidence indicates that impaired cellular energy metabolism is the defining characteristic of nearly all cancers regardless of cellular or tissue origin. In contrast to normal cells, which derive most of their usable energy from oxidative phosphorylation, most cancer cells become heavily dependent on substrate level phosphorylation to meet energy demands. Evidence is reviewed supporting a general hypothesis that genomic instability and essentially all hallmarks of cancer, including aerobic glycolysis (Warburg effect), can be linked to impaired mitochondrial function and energy metabolism. A view of cancer as primarily a metabolic disease will impact approaches to cancer management and prevention.
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In vitro growth environment produces lipidomic and electron transport chain abnormalities in mitochondria from non-tumorigenic astrocytes and brain tumours. ASN Neuro 2009; 1:AN20090011. [PMID: 19570033 PMCID: PMC2695587 DOI: 10.1042/an20090011] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The mitochondrial lipidome influences ETC (electron transport chain) and cellular bioenergetic efficiency. Brain tumours are largely dependent on glycolysis for energy due to defects in mitochondria and oxidative phosphorylation. In the present study, we used shotgun lipidomics to compare the lipidome in highly purified mitochondria isolated from normal brain, from brain tumour tissue, from cultured tumour cells and from non-tumorigenic astrocytes. The tumours included the CT-2A astrocytoma and an EPEN (ependymoblastoma), both syngeneic with the C57BL/6J (B6) mouse strain. The mitochondrial lipidome in cultured CT-2A and EPEN tumour cells were compared with those in cultured astrocytes and in solid tumours grown in vivo. Major differences were found between normal tissue and tumour tissue and between in vivo and in vitro growth environments for the content or composition of ethanolamine glycerophospholipids, phosphatidylglycerol and cardiolipin. The mitochondrial lipid abnormalities in solid tumours and in cultured cells were associated with reductions in multiple ETC activities, especially Complex I. The in vitro growth environment produced lipid and ETC abnormalities in cultured non-tumorigenic astrocytes that were similar to those associated with tumorigenicity. It appears that the culture environment obscures the boundaries of the Crabtree and the Warburg effects. These results indicate that in vitro growth environments can produce abnormalities in mitochondrial lipids and ETC activities, thus contributing to a dependency on glycolysis for ATP production.
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