1
|
Ramos PM, Wohlgemuth SE, Gingerich CA, Hawryluk B, Smith MT, Bell LC, Scheffler TL. Postmortem mitochondria function in longissimus lumborum of Angus and Brahman steers. Meat Sci 2024; 215:109538. [PMID: 38772311 DOI: 10.1016/j.meatsci.2024.109538] [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: 02/16/2024] [Revised: 04/09/2024] [Accepted: 05/09/2024] [Indexed: 05/23/2024]
Abstract
Mitochondria function and integrity may impact postmortem metabolism and meat quality development. Adaptations in heat tolerant Brahman may persist to limit cellular stress postmortem. Our objective was to evaluate glycolysis, pH decline, and mitochondria function in longissimus lumborum (LL) from Angus and Brahman steers (N = 28) early postmortem (1 to 6 h) and after rigor (24 h). We evaluated metabolites of anaerobic glycolysis, ATP, pH, and temperature, and determined mitochondria oxygen consumption rate (OCR) in permeabilized fibers. The main effects of breed (b) and time (t) and the interaction were tested. Brahman LL contained greater ATP during the first 6 h postmortem; Brahman also tended to exhibit a slower pH decline (b × t, P = 0.07) and more rapid temperature decline (b × t, P < 0.001), but metabolites of anaerobic glycolysis were not different. Mitochondria in Brahman and Angus LL were well-coupled and respired at 1 h postmortem. However, outer membrane integrity became increasingly compromised postmortem (t, P < 0.001). Brahman tended to exhibit greater electron transport system capacity (b, P < 0.1) and had greater capacity for oxidative phosphorylation (complex I and II substrates) at 6 h compared with Angus (P < 0.001). In totality, greater ATP, slower pH decline, and enhanced mitochondria capacity indicate that Brahman possess mitochondrial properties or cellular adaptations that help protect the cell during energy stress postmortem. Slower pH and more rapid temperature decline in LL from Brahman may also help preserve mitochondria function postmortem.
Collapse
Affiliation(s)
- Patricia M Ramos
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611, United States of America
| | - Stephanie E Wohlgemuth
- Department of Physiology and Aging, University of Florida, Gainesville, FL 32603, United States of America
| | - Chloe A Gingerich
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611, United States of America
| | - Briana Hawryluk
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611, United States of America
| | - Morgan T Smith
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611, United States of America
| | - Lindsey C Bell
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611, United States of America
| | - Tracy L Scheffler
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611, United States of America.
| |
Collapse
|
2
|
MacColl Garfinkel A, Mnatsakanyan N, Patel JH, Wills AE, Shteyman A, Smith PJS, Alavian KN, Jonas EA, Khokha MK. Mitochondrial leak metabolism induces the Spemann-Mangold Organizer via Hif-1α in Xenopus. Dev Cell 2023; 58:2597-2613.e4. [PMID: 37673063 PMCID: PMC10840693 DOI: 10.1016/j.devcel.2023.08.015] [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: 06/23/2022] [Revised: 06/30/2023] [Accepted: 08/09/2023] [Indexed: 09/08/2023]
Abstract
An instructive role for metabolism in embryonic patterning is emerging, although a role for mitochondria is poorly defined. We demonstrate that mitochondrial oxidative metabolism establishes the embryonic patterning center, the Spemann-Mangold Organizer, via hypoxia-inducible factor 1α (Hif-1α) in Xenopus. Hypoxia or decoupling ATP production from oxygen consumption expands the Organizer by activating Hif-1α. In addition, oxygen consumption is 20% higher in the Organizer than in the ventral mesoderm, indicating an elevation in mitochondrial respiration. To reconcile increased mitochondrial respiration with activation of Hif-1α, we discovered that the "free" c-subunit ring of the F1Fo ATP synthase creates an inner mitochondrial membrane leak, which decouples ATP production from respiration at the Organizer, driving Hif-1α activation there. Overexpression of either the c-subunit or Hif-1α is sufficient to induce Organizer cell fates even when β-catenin is inhibited. We propose that mitochondrial leak metabolism could be a general mechanism for activating Hif-1α and Wnt signaling.
Collapse
Affiliation(s)
- Alexandra MacColl Garfinkel
- Pediatric Genomics Discovery Program, Department of Pediatrics and Genetics, Yale University School of Medicine, New Haven, CT 06510, USA; Section of Endocrinology, Department of Internal Medicine, Yale University, New Haven, CT 06510, USA
| | - Nelli Mnatsakanyan
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Jeet H Patel
- Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195, USA; Program in Molecular and Cellular Biology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Andrea E Wills
- Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195, USA; Institute for Stem Cell and Regenerative Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Amy Shteyman
- Section of Endocrinology, Department of Internal Medicine, Yale University, New Haven, CT 06510, USA
| | - Peter J S Smith
- Institute for Life Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | | | - Elizabeth Ann Jonas
- Section of Endocrinology, Department of Internal Medicine, Yale University, New Haven, CT 06510, USA.
| | - Mustafa K Khokha
- Pediatric Genomics Discovery Program, Department of Pediatrics and Genetics, Yale University School of Medicine, New Haven, CT 06510, USA.
| |
Collapse
|
3
|
Hatokova Z, Evinova A, Racay P. STF-083010 an inhibitor of IRE1α endonuclease activity affects mitochondrial respiration and generation of mitochondrial membrane potential. Toxicol In Vitro 2023; 92:105652. [PMID: 37482139 DOI: 10.1016/j.tiv.2023.105652] [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: 03/05/2023] [Revised: 06/18/2023] [Accepted: 07/21/2023] [Indexed: 07/25/2023]
Abstract
STF-083010 is an inhibitor of endonuclease activity of inositol requiring-enzyme 1α (IRE1α) that is involved in activation of IRE1α-XBP1 axis of the unfolded protein response after ER stress. STF-083010 was tested as a possible antitumor agent in some previous studies exhibiting the ability either to induce death of tumour cells or to increase sensitivity of tumours cells to other neoplastic agents. STF-083010 exhibits also hepatoprotective effects in different models of liver injury and hepatic steatohepatitis. We have shown that STF-083010 has significant impact on mitochondrial functions that is not dependent on the way of STF-083010 application. We have observed that STF-083010 decrease of both maximal respiration (representing maximal electron transfer capacity of mitochondrial respiratory chain) and spare respiratory capacity after either incubation of the SH-SY5Y cells with STF-083010 or direct addition of STF-083010 to the respiration medium. In addition, we have documented impact of STF-083010 on generation of mitochondrial membrane potential (ΔΨm) that could be a result of decreased mitochondrial substrate level phosphorylation. Finally, increased sensitivity of ΔΨm to uncoupler in the presence of STF-083010 was documented. Our results indicate that STF-083010 has important impact on mitochondrial functions independently of its ability to inhibit endonuclease activity of IRE1α that is involved in activation of IRE1α-XBP1 axis of the unfolded protein response after ER stress. The impact of STF-083010 on mitochondrial functions could be associated with its possible off-target effect.
Collapse
Affiliation(s)
- Zuzana Hatokova
- Biomedical Center Martin, Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin (JFM CU), Slovak Republic
| | - Andrea Evinova
- Biomedical Center Martin, Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin (JFM CU), Slovak Republic
| | - Peter Racay
- Department of Medical Biochemistry JFM CU, JFM CU Martin, Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin (JFM CU), Slovak Republic.
| |
Collapse
|
4
|
Begum HM, Shen K. Intracellular and microenvironmental regulation of mitochondrial membrane potential in cancer cells. WIREs Mech Dis 2023; 15:e1595. [PMID: 36597256 PMCID: PMC10176868 DOI: 10.1002/wsbm.1595] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 12/08/2022] [Accepted: 12/15/2022] [Indexed: 01/05/2023]
Abstract
Cancer cells have an abnormally high mitochondrial membrane potential (ΔΨm ), which is associated with enhanced invasive properties in vitro and increased metastases in vivo. The mechanisms underlying the abnormal ΔΨm in cancer cells remain unclear. Research on different cell types has shown that ΔΨm is regulated by various intracellular mechanisms such as by mitochondrial inner and outer membrane ion transporters, cytoskeletal elements, and biochemical signaling pathways. On the other hand, the role of extrinsic, tumor microenvironment (TME) derived cues in regulating ΔΨm is not well defined. In this review, we first summarize the existing literature on intercellular mechanisms of ΔΨm regulation, with a focus on cancer cells. We then offer our perspective on the different ways through which the microenvironmental cues such as hypoxia and mechanical stresses may regulate cancer cell ΔΨm . This article is categorized under: Cancer > Environmental Factors Cancer > Biomedical Engineering Cancer > Molecular and Cellular Physiology.
Collapse
Affiliation(s)
- Hydari Masuma Begum
- Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089
| | - Keyue Shen
- Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA 90089
- USC Stem Cell, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033
- Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033
| |
Collapse
|
5
|
Reed KJ, Landry GM. Diglycolic acid inhibits succinate dehydrogenase activity, depletes mitochondrial membrane potential, and induces inflammation in an SH-SY5Y neuroblastoma model of neurotoxicity in vitro. Toxicol Appl Pharmacol 2023; 463:116414. [PMID: 36754214 DOI: 10.1016/j.taap.2023.116414] [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: 11/08/2022] [Revised: 01/31/2023] [Accepted: 02/01/2023] [Indexed: 02/08/2023]
Abstract
Diethylene glycol is a toxic industrial solvent resulting in a well-defined toxidrome. Diglycolic acid (DGA) has been identified as the metabolite responsible for the nephrotoxicity and hepatotoxicity. These studies assess the mechanism of DGA-induced neurotoxicity, specifically addressing the known ability of DGA to chelate calcium (Ca2+) in solution and inhibit mitochondrial complex II. SH-SY5Y cells were seeded into 96-well plates to assess intracellular Ca2+ chelation, complex II activity, mitochondrial membrane potential (ΔΨm), ATP production, and release of inflammatory cytokines TNF-α and IL-1β with 2-, 4-, 6-, 24-, and 48-h DGA exposure. Peak Ca2+ chelation occurred at 4 h in cells treated with 6.25-50 mM DGA; however, effects were transient. Complex II activity was significantly decreased at all DGA concentrations tested, with 12.5 mM DGA causing 80% inhibition and 25 and 50 mM DGA causing 97 and 100% inhibition, respectively. Subsequently, 12.5-50 mM DGA concentrations significantly decreased ΔΨm at all time points. 50 mM DGA significantly increased release of TNF-α and IL-1β after 24 and 48 h with significantly decreased ATP production observed at the same time points and concentration. These studies demonstrate that the DGA-induced mechanism of SH-SY5Y cell death involves complex II inhibition leading to mitochondrial depolarization, and subsequent ATP depletion with accompanying inflammatory cytokine release. These results indicate a direct mechanism of DGA-induced neurotoxicity in vitro, similarly observed in other DEG-affected target organs.
Collapse
Affiliation(s)
- Kristi J Reed
- Massachusetts College of Pharmacy and Health Sciences, School of Pharmacy, Department of Pharmaceutical Sciences, Boston, MA 02115, United States
| | - Greg M Landry
- Massachusetts College of Pharmacy and Health Sciences, School of Pharmacy, Department of Pharmaceutical Sciences, Boston, MA 02115, United States.
| |
Collapse
|
6
|
Temozolomide, Simvastatin and Acetylshikonin Combination Induces Mitochondrial-Dependent Apoptosis in GBM Cells, Which Is Regulated by Autophagy. BIOLOGY 2023; 12:biology12020302. [PMID: 36829578 PMCID: PMC9953749 DOI: 10.3390/biology12020302] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/07/2023] [Accepted: 02/10/2023] [Indexed: 02/16/2023]
Abstract
Glioblastoma multiforme (GBM) is one of the deadliest cancers. Temozolomide (TMZ) is the most common chemotherapy used for GBM patients. Recently, combination chemotherapy strategies have had more effective antitumor effects and focus on slowing down the development of chemotherapy resistance. A combination of TMZ and cholesterol-lowering medications (statins) is currently under investigation in in vivo and clinical trials. In our current investigation, we have used a triple-combination therapy of TMZ, Simvastatin (Simva), and acetylshikonin, and investigated its apoptotic mechanism in GBM cell lines (U87 and U251). We used viability, apoptosis, reactive oxygen species, mitochondrial membrane potential (MMP), caspase-3/-7, acridine orange (AO) and immunoblotting autophagy assays. Our results showed that a TMZ/Simva/ASH combination therapy induced significantly more apoptosis compared to TMZ, Simva, ASH, and TMZ/Simva treatments in GBM cells. Apoptosis via TMZ/Simva/ASH treatment induced mitochondrial damage (increase of ROS, decrease of MMP) and caspase-3/7 activation in both GBM cell lines. Compared to all single treatments and the TMZ/Simva treatment, TMZ/Simva/ASH significantly increased positive acidic vacuole organelles. We further confirmed that the increase of AVOs during the TMZ/Simva/ASH treatment was due to the partial inhibition of autophagy flux (accumulation of LC3β-II and a decrease in p62 degradation) in GBM cells. Our investigation also showed that TMZ/Simva/ASH-induced cell death was depended on autophagy flux, as further inhibition of autophagy flux increased TMZ/Simva/ASH-induced cell death in GBM cells. Finally, our results showed that TMZ/Simva/ASH treatment potentially depends on an increase of Bax expression in GBM cells. Our current investigation might open new avenues for a more effective treatment of GBM, but further investigations are required for a better identification of the mechanisms.
Collapse
|
7
|
Germanova E, Khmil N, Pavlik L, Mikheeva I, Mironova G, Lukyanova L. The Role of Mitochondrial Enzymes, Succinate-Coupled Signaling Pathways and Mitochondrial Ultrastructure in the Formation of Urgent Adaptation to Acute Hypoxia in the Myocardium. Int J Mol Sci 2022; 23:ijms232214248. [PMID: 36430733 PMCID: PMC9696391 DOI: 10.3390/ijms232214248] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/21/2022] [Accepted: 11/13/2022] [Indexed: 11/19/2022] Open
Abstract
The effect of a single one-hour exposure to three modes of hypobaric hypoxia (HBH) differed in the content of O2 in inhaled air (FiO2-14%, 10%, 8%) in the development of mitochondrial-dependent adaptive processes in the myocardium was studied in vivo. The following parameters have been examined: (a) an urgent reaction of catalytic subunits of mitochondrial enzymes (NDUFV2, SDHA, Cyt b, COX2, ATP5A) in the myocardium as an indicator of the state of the respiratory chain electron transport function; (b) an urgent activation of signaling pathways dependent on GPR91, HIF-1α and VEGF, allowing us to assess their role in the formation of urgent mechanisms of adaptation to hypoxia in the myocardium; (c) changes in the ultrastructure of three subpopulations of myocardial mitochondria under these conditions. The studies were conducted on two rat phenotypes: rats with low resistance (LR) and high resistance (HR) to hypoxia. The adaptive and compensatory role of the mitochondrial complex II (MC II) in maintaining the electron transport and energy function of the myocardium in a wide range of reduced O2 concentrations in the initial period of hypoxic exposure has been established. The features of urgent reciprocal regulatory interaction of NAD- and FAD-dependent oxidation pathways in myocardial mitochondria under these conditions have been revealed. The data indicating the participation of GPR91, HIF-1a and VEGF in this process have been obtained. The ultrastructure of the mitochondrial subpopulations in the myocardium of LR and HR rats differed in normoxic conditions and reacted differently to hypoxia of varying severity. The parameters studied together are highly informative indicators of the quality of cardiac activity and metabolic biomarkers of urgent adaptation in various hypoxic conditions.
Collapse
Affiliation(s)
- Elita Germanova
- Institute of General Pathology and Pathophysiology, 8 Baltijskaya Str., Moscow 125315, Russia
| | - Natalya Khmil
- Institute of Theoretical and Experimental Biophysics RAS, 3 Institutskaya Str., Pushchino 142290, Moscow Region, Russia
| | - Lyubov Pavlik
- Institute of Theoretical and Experimental Biophysics RAS, 3 Institutskaya Str., Pushchino 142290, Moscow Region, Russia
| | - Irina Mikheeva
- Institute of Theoretical and Experimental Biophysics RAS, 3 Institutskaya Str., Pushchino 142290, Moscow Region, Russia
| | - Galina Mironova
- Institute of Theoretical and Experimental Biophysics RAS, 3 Institutskaya Str., Pushchino 142290, Moscow Region, Russia
- Correspondence: (G.M.); (L.L.)
| | - Ludmila Lukyanova
- Institute of General Pathology and Pathophysiology, 8 Baltijskaya Str., Moscow 125315, Russia
- Correspondence: (G.M.); (L.L.)
| |
Collapse
|
8
|
Lee S, Xu H, Van Vleck A, Mawla AM, Li AM, Ye J, Huising MO, Annes JP. β-Cell Succinate Dehydrogenase Deficiency Triggers Metabolic Dysfunction and Insulinopenic Diabetes. Diabetes 2022; 71:1439-1453. [PMID: 35472723 PMCID: PMC9233299 DOI: 10.2337/db21-0834] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 03/26/2022] [Indexed: 11/20/2022]
Abstract
Mitochondrial dysfunction plays a central role in type 2 diabetes (T2D); however, the pathogenic mechanisms in pancreatic β-cells are incompletely elucidated. Succinate dehydrogenase (SDH) is a key mitochondrial enzyme with dual functions in the tricarboxylic acid cycle and electron transport chain. Using samples from human with diabetes and a mouse model of β-cell-specific SDH ablation (SDHBβKO), we define SDH deficiency as a driver of mitochondrial dysfunction in β-cell failure and insulinopenic diabetes. β-Cell SDH deficiency impairs glucose-induced respiratory oxidative phosphorylation and mitochondrial membrane potential collapse, thereby compromising glucose-stimulated ATP production, insulin secretion, and β-cell growth. Mechanistically, metabolomic and transcriptomic studies reveal that the loss of SDH causes excess succinate accumulation, which inappropriately activates mammalian target of rapamycin (mTOR) complex 1-regulated metabolic anabolism, including increased SREBP-regulated lipid synthesis. These alterations, which mirror diabetes-associated human β-cell dysfunction, are partially reversed by acute mTOR inhibition with rapamycin. We propose SDH deficiency as a contributing mechanism to the progressive β-cell failure of diabetes and identify mTOR complex 1 inhibition as a potential mitigation strategy.
Collapse
Affiliation(s)
- Sooyeon Lee
- Division of Endocrinology, Department of Medicine, Stanford University, Stanford, CA
| | - Haixia Xu
- Division of Endocrinology, Department of Medicine, Stanford University, Stanford, CA
| | - Aidan Van Vleck
- Division of Endocrinology, Department of Medicine, Stanford University, Stanford, CA
| | - Alex M. Mawla
- Department of Neurobiology, Physiology and Behavior, College of Biological Sciences, University of California, Davis, Davis, CA
| | - Albert Mao Li
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
- Cancer Biology Program, Stanford University School of Medicine, Stanford, CA
| | - Jiangbin Ye
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA
- Cancer Biology Program, Stanford University School of Medicine, Stanford, CA
| | - Mark O. Huising
- Department of Neurobiology, Physiology and Behavior, College of Biological Sciences, University of California, Davis, Davis, CA
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, Davis, CA
| | - Justin P. Annes
- Division of Endocrinology, Department of Medicine, Stanford University, Stanford, CA
- Stanford ChEM-H and Diabetes Research Center, Stanford University School of Medicine, Stanford, CA
| |
Collapse
|
9
|
Anti-aging effects of chlorpropamide depend on mitochondrial complex-II and the production of mitochondrial reactive oxygen species. Acta Pharm Sin B 2022; 12:665-677. [PMID: 35256938 PMCID: PMC8897034 DOI: 10.1016/j.apsb.2021.08.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 07/22/2021] [Accepted: 07/30/2021] [Indexed: 12/11/2022] Open
Abstract
Sulfonylureas are widely used oral anti-diabetic drugs. However, its long-term usage effects on patients’ lifespan remain controversial, with no reports of influence on animal longevity. Hence, the anti-aging effects of chlorpropamide along with glimepiride, glibenclamide, and tolbutamide were studied with special emphasis on the interaction of chlorpropamide with mitochondrial ATP-sensitive K+ (mitoK-ATP) channels and mitochondrial complex II. Chlorpropamide delayed aging in Caenorhabditis elegans, human lung fibroblast MRC-5 cells and reduced doxorubicin-induced senescence in both MRC-5 cells and mice. In addition, the mitochondrial membrane potential and ATP levels were significantly increased in chlorpropamide-treated worms, which is consistent with the function of its reported targets, mitoK-ATP channels. Increased levels of mitochondrial reactive oxygen species (mtROS) were observed in chlorpropamide-treated worms. Moreover, the lifespan extension by chlorpropamide required complex II and increased mtROS levels, indicating that chlorpropamide acts on complex II directly or indirectly via mitoK-ATP to increase the production of mtROS as a pro-longevity signal. This study provides mechanistic insight into the anti-aging effects of sulfonylureas in C. elegans.
Collapse
|
10
|
Orlov Y, Butrov A, Sviridov S, Afanasyev V. Succinate salts in solving the «oxygen paradox» of reperfusion. Zh Nevrol Psikhiatr Im S S Korsakova 2022; 122:63-69. [DOI: 10.17116/jnevro202212209163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
11
|
Lukyanova L, Germanova E, Khmil N, Pavlik L, Mikheeva I, Shigaeva M, Mironova G. Signaling Role of Mitochondrial Enzymes and Ultrastructure in the Formation of Molecular Mechanisms of Adaptation to Hypoxia. Int J Mol Sci 2021; 22:8636. [PMID: 34445340 PMCID: PMC8395493 DOI: 10.3390/ijms22168636] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 08/02/2021] [Accepted: 08/05/2021] [Indexed: 01/16/2023] Open
Abstract
This study was the first comprehensive investigation of the dependence of mitochondrial enzyme response (catalytic subunits of mitochondrial complexes (MC) I-V, including NDUFV2, SDHA, Cyt b, COX1 and ATP5A) and mitochondrial ultrastructure in the rat cerebral cortex (CC) on the severity and duration of in vivo hypoxic exposures. The role of individual animal's resistance to hypoxia was also studied. The respiratory chain (RC) was shown to respond to changes in environmental [O2] as follows: (a) differential reaction of mitochondrial enzymes, which depends on the severity of the hypoxic exposure and which indicates changes in the content and catalytic properties of mitochondrial enzymes, both during acute and multiple exposures; and (b) ultrastructural changes in mitochondria, which reflect various degrees of mitochondrial energization. Within a specific range of reduced O2 concentrations, activation of the MC II is a compensatory response supporting the RC electron transport function. In this process, MC I develops new kinetic properties, and its function recovers in hypoxia by reprograming the RC substrate site. Therefore, the mitochondrial RC performs as an in vivo molecular oxygen sensor. Substantial differences between responses of rats with high and low resistance to hypoxia were determined.
Collapse
Affiliation(s)
- Ludmila Lukyanova
- Institute of General Pathology and Pathophysiology, Baltijskaya Str. 8., 125315 Moscow, Russia;
| | - Elita Germanova
- Institute of General Pathology and Pathophysiology, Baltijskaya Str. 8., 125315 Moscow, Russia;
| | - Natalya Khmil
- Institute of Theoretical and Experimental Biophysics RAS, Pushchino, 142290 Moscow, Russia; (N.K.); (L.P.); (I.M.); (M.S.)
| | - Lybov Pavlik
- Institute of Theoretical and Experimental Biophysics RAS, Pushchino, 142290 Moscow, Russia; (N.K.); (L.P.); (I.M.); (M.S.)
| | - Irina Mikheeva
- Institute of Theoretical and Experimental Biophysics RAS, Pushchino, 142290 Moscow, Russia; (N.K.); (L.P.); (I.M.); (M.S.)
| | - Maria Shigaeva
- Institute of Theoretical and Experimental Biophysics RAS, Pushchino, 142290 Moscow, Russia; (N.K.); (L.P.); (I.M.); (M.S.)
| | - Galina Mironova
- Institute of Theoretical and Experimental Biophysics RAS, Pushchino, 142290 Moscow, Russia; (N.K.); (L.P.); (I.M.); (M.S.)
| |
Collapse
|
12
|
Arias-Reyes C, Soliz J, Joseph V. Mice and Rats Display Different Ventilatory, Hematological, and Metabolic Features of Acclimatization to Hypoxia. Front Physiol 2021; 12:647822. [PMID: 33776799 PMCID: PMC7994900 DOI: 10.3389/fphys.2021.647822] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 02/15/2021] [Indexed: 11/13/2022] Open
Abstract
Phylogeographic studies showed that house mice (Mus musculus) originated in the Himalayan region, while common rats (Rattus rattus and Rattus norvegicus) come from the lowlands of China and India. Accordingly, it has been proposed that its origins gave mice, but not rats, the ability to invade ecological niches at high altitudes (pre-adaptation). This proposal is strongly supported by the fact that house mice are distributed throughout the world, while common rats are practically absent above 2,500 m. Considering that the ability of mammals to colonize high-altitude environments (>2,500 m) is limited by their capability to tolerate reduced oxygen availability, in this work, we hypothesize that divergences in the ventilatory, hematological, and metabolic phenotypes of mice and rats establish during the process of acclimatization to hypoxia (Hx). To test this hypothesis male FVB mice and Sprague-Dawley (SD) rats were exposed to Hx (12% O2) for 0 h (normoxic controls), 6 h, 1, 7, and 21 days. We assessed changes in ventilatory [minute ventilation (VE), respiratory frequency (fR), and tidal volume (VT)], hematological (hematocrit and hemoglobin concentration), and metabolic [whole-body O2 consumption (VO2) and CO2 production (VCO2), and liver mitochondrial oxygen consumption rate (OCR) parameters]. Compared to rats, results in mice show increased ventilatory, metabolic, and mitochondrial response. In contrast, rats showed quicker and higher hematological response than mice and only minor ventilatory and metabolic adjustments. Our findings may explain, at least in part, why mice, but not rats, were able to colonize high-altitude habitats.
Collapse
Affiliation(s)
- Christian Arias-Reyes
- Centre de Recherche de l'Institute Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, Canada
| | - Jorge Soliz
- Centre de Recherche de l'Institute Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, Canada
| | - Vincent Joseph
- Centre de Recherche de l'Institute Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, Canada
| |
Collapse
|
13
|
Correction of mitochondrial dysfunction by succinic acid derivatives under experimental cerebral ischemia conditions. CURRENT ISSUES IN PHARMACY AND MEDICAL SCIENCES 2021. [DOI: 10.2478/cipms-2021-0008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
The aim of the study. To evaluate the effect of succinic acid derivatives on changes of mitochondrial function in rats under cerebral ischemia conditions.
Materials and methods. In this work, the effect of succinic acid, ethylmethylhydroxypyridine succinate, and acetylaminosuccinic acid at doses of 50 mg/kg, 100 mg/kg, and 200 mg/kg (per os) on the change of the neuronal mitochondria function was studied. Cerebral ischemia was reproduced by the Tamura method. The following parameters were evaluated: changes in aerobic/anaerobic metabolism, mitochondrial membrane potential, the opening rate of the mitochondrial pore of transitional permeability and the activity of apoptotic systems.
Results. During the study, it was found that the use of the test-compounds at doses of 100 mg/kg and 200 mg/kg contributed to an increase in ATP-generating activity, as well as the maximum respiration level and respiratory capacity, while accompanied by a decrease in the intensity of anaerobic metabolism reactions. Also, upon administration of the test succinic acid derivatives, an increase in the mitochondrial membrane potential and latent opening time of the mitochondrial pore transitional permeability were observed. Moreover, the activity of caspase-3 and apoptosis-inducing factor on groups treated by test objects at doses of 100 mg/kg and 200 mg/kg was significantly lower than that in untreated animals.
Conclusion. The studied succinic acid derivatives contribute to the restoration of mitochondrial function in cerebral ischemia conditions, while the most effective dose can be considered to be 100 mg/kg.
Collapse
|
14
|
Silva PJ. Chemiosmotic misunderstandings. Biophys Chem 2020; 264:106424. [PMID: 32717593 DOI: 10.1016/j.bpc.2020.106424] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 06/19/2020] [Accepted: 06/21/2020] [Indexed: 02/04/2023]
Abstract
Recent publications have questioned the appropriateness of the chemiosmotic theory, a key tenet of modern bioenergetics originally described by Mitchell and since widely improved upon and applied. In one of them, application of Gauss' law to a model charge distribution in mitochondria was argued to refute the possibility of ATP generation through H+ movement in the absence of a counterion, whereas a different author advocated, for other reasons, the impossibility of chemiosmosis and proposed that a novel energy-generation scheme (referred to as "murburn") relying on superoxide-catalyzed (or superoxide-promoted) ADP phosphorylation would operate instead. In this letter, those proposals are critically examined and found to be inconsistent with established experimental data and new theoretical calculations.
Collapse
Affiliation(s)
- Pedro J Silva
- FP-ENAS/Fac. de Ciências da Saúde, Universidade Fernando Pessoa, Porto, Portugal; UCIBIO@REQUIMTE, BioSIM, Departamento de Biomedicina, Faculdade de Medicina, Universidade do Porto, Porto, Portugal.
| |
Collapse
|
15
|
Jaña F, Bustos G, Rivas J, Cruz P, Urra F, Basualto-Alarcón C, Sagredo E, Ríos M, Lovy A, Dong Z, Cerda O, Madesh M, Cárdenas C. Complex I and II are required for normal mitochondrial Ca 2+ homeostasis. Mitochondrion 2019; 49:73-82. [PMID: 31310854 DOI: 10.1016/j.mito.2019.07.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 04/01/2019] [Accepted: 07/12/2019] [Indexed: 01/03/2023]
Abstract
Cytosolic calcium (cCa2+) entry into mitochondria is facilitated by the mitochondrial membrane potential (ΔΨm), an electrochemical gradient generated by the electron transport chain (ETC). Is has been assumed that as long as mutations that affect the ETC do not affect the ΔΨm, the mitochondrial Ca2+ (mCa2+) homeostasis remains normal. We show that knockdown of NDUFAF3 and SDHB reduce ETC activity altering mCa2+ efflux and influx rates while ΔΨm remains intact. Shifting the equilibrium toward lower [Ca2+]m accumulation renders cells resistant to death. Our findings reveal an unexpected relationship between complex I and II with the mCa2+ homeostasis independent of ΔΨm.
Collapse
Affiliation(s)
- Fabian Jaña
- Departamento de Ciencias de la Salud, Universidad de Aysén, Coyhaique, Chile; Geroscience Center for Brain Health and Metabolism, Santiago, Chile
| | - Galdo Bustos
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile; Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile
| | - José Rivas
- Departamento de Ciencias de la Salud, Universidad de Aysén, Coyhaique, Chile; Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Pablo Cruz
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile; Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Felix Urra
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile; Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Carla Basualto-Alarcón
- Departamento de Ciencias de la Salud, Universidad de Aysén, Coyhaique, Chile; Geroscience Center for Brain Health and Metabolism, Santiago, Chile; Anatomy and Legal Medicine Department, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Eduardo Sagredo
- Centro de Investigación y Tratamiento del Cáncer, Facultad de Medicina, Universidad de Chile, Chile
| | - Melany Ríos
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile
| | - Alenka Lovy
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile; Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile; Center for Neuroscience Research, Tufts University School of Medicine, Boston, MA, USA
| | - Zhiwei Dong
- Department of Medicine, Center for Precision Medicine, University of Texas Health San Antonio, TX, USA
| | - Oscar Cerda
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago, Chile; Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Santiago, Chile.; The Wound Repair, Treatment and Health (WoRTH), Chile
| | - Muniswamy Madesh
- Department of Medicine, Center for Precision Medicine, University of Texas Health San Antonio, TX, USA.
| | - César Cárdenas
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile; Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile; Buck Institute for Research on Aging, Novato, CA, USA; Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, United States.
| |
Collapse
|
16
|
Potes Y, Pérez-Martinez Z, Bermejo-Millo JC, Rubio-Gonzalez A, Fernandez-Fernández M, Bermudez M, Arche JM, Solano JJ, Boga JA, Oliván M, Caballero B, Vega-Naredo I, Coto-Montes A. Overweight in the Elderly Induces a Switch in Energy Metabolism that Undermines Muscle Integrity. Aging Dis 2019; 10:217-230. [PMID: 31011474 PMCID: PMC6457058 DOI: 10.14336/ad.2018.0430] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 04/30/2018] [Indexed: 12/19/2022] Open
Abstract
Aging is characterized by a progressive loss of skeletal muscle mass and function (sarcopenia). Obesity exacerbates age-related decline and lead to frailty. Skeletal muscle fat infiltration increases with aging and seems to be crucial for the progression of sarcopenia. Additionally, skeletal muscle plasticity modulates metabolic adaptation to different pathophysiological situations. Thus, cellular bioenergetics and mitochondrial profile were studied in the skeletal muscle of overweight aged people without reaching obesity to prevent this extreme situation. Overweight aged muscle lacked ATP production, as indicated by defects in the phosphagen system, glycolysis and especially mostly by oxidative phosphorylation metabolic pathway. Overweight subjects exhibited an inhibition of mitophagy that was linked to an increase in mitochondrial biogenesis that underlies the accumulation of dysfunctional mitochondria and encourages the onset of sarcopenia. As a strategy to maintain cellular homeostasis, overweight subjects experienced a metabolic switch from oxidative to lactic acid fermentation metabolism, which allows continued ATP production under mitochondrial dysfunction, but without reaching physiological aged basal levels. This ATP depletion induced early signs of impaired contractile function and a decline in skeletal muscle structural integrity, evidenced by lower levels of filamin C. Our findings reveal the main effector pathways at an early stage of obesity and highlight the importance of mitochondrial metabolism in overweight and obese individuals. Exploiting mitochondrial profiles for therapeutic purposes in humans is an ambitious strategy for treating muscle impairment diseases.
Collapse
Affiliation(s)
- Yaiza Potes
- 1Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, Asturias, Spain.,2Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Spain
| | | | - Juan C Bermejo-Millo
- 1Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, Asturias, Spain.,2Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Spain
| | - Adrian Rubio-Gonzalez
- 1Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, Asturias, Spain
| | | | | | - Jose M Arche
- 4Geriatric Service, Monte Naranco Hospital, Asturias, Spain
| | - Juan J Solano
- 2Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Spain.,4Geriatric Service, Monte Naranco Hospital, Asturias, Spain
| | - Jose A Boga
- 3Microbiology Service, Central University Hospital of Asturias, Asturias, Spain
| | - Mamen Oliván
- 2Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Spain.,5Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA), Asturias, Spain
| | - Beatriz Caballero
- 1Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, Asturias, Spain.,2Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Spain
| | - Ignacio Vega-Naredo
- 1Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, Asturias, Spain.,2Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Spain
| | - Ana Coto-Montes
- 1Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, Asturias, Spain.,2Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Spain
| |
Collapse
|
17
|
Vasin MV, Ushakov IB. Activation of Respiratory Chain Complex II as a Hypoxia Tolerance Indicator during Acute Hypoxia. Biophysics (Nagoya-shi) 2018. [DOI: 10.1134/s0006350918020252] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
18
|
Mitochondrial biogenesis and metabolic hyperactivation limits the application of MTT assay in the estimation of radiation induced growth inhibition. Sci Rep 2018; 8:1531. [PMID: 29367754 PMCID: PMC5784148 DOI: 10.1038/s41598-018-19930-w] [Citation(s) in RCA: 172] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 01/05/2018] [Indexed: 01/19/2023] Open
Abstract
Metabolic viability based high throughput assays like MTT and MTS are widely used in assessing the cell viability. However, alteration in both mitochondrial content and metabolism can influence the metabolic viability of cells and radiation is a potential mitochondrial biogenesis inducer. Therefore, we tested if MTT assay is a true measure of radiation induced cell death in widely used cell lines. Radiation induced cellular growth inhibition was performed by enumerating cell numbers and metabolic viability using MTT assay at 24 and 48 hours (hrs) after exposure. The extent of radiation induced reduction in cell number was found to be larger than the decrease in MTT reduction in all the cell lines tested. We demonstrated that radiation induces PGC-1α and TFAM to stimulate mitochondrial biogenesis leading to increased levels of SDH-A and enhanced metabolic viability. Radiation induced disturbance in calcium (Ca2+) homeostasis also plays a crucial role by making the mitochondria hyperactive. These findings suggest that radiation induces mitochondrial biogenesis and hyperactivation leading to increased metabolic viability and MTT reduction. Therefore, conclusions drawn on radiation induced growth inhibition based on metabolic viability assays are likely to be erroneous as it may not correlate with growth inhibition and/or loss of clonogenic survival.
Collapse
|
19
|
Lukyanova LD, Kirova YI, Germanova EL. The Role of Succinate in Regulation of Immediate HIF-1α Expression in Hypoxia. Bull Exp Biol Med 2018; 164:298-303. [DOI: 10.1007/s10517-018-3976-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Indexed: 11/28/2022]
|
20
|
Lau GY, Richards JG. Interspecific variation in brain mitochondrial complex I and II capacity and ROS emission in marine sculpins. J Exp Biol 2018; 222:jeb.189407. [DOI: 10.1242/jeb.189407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 11/29/2018] [Indexed: 12/29/2022]
Abstract
Environmental hypoxia presents a metabolic challenge for animals because it inhibits mitochondrial respiration and can lead to the generation of reactive oxygen species (ROS). We investigated the interplay between O2 use for aerobic respiration and ROS generation among sculpin fishes (Cottidae, Actinopterygii) that are known to vary in whole-animal hypoxia tolerance. We hypothesized that mitochondria from hypoxia tolerant sculpins would show more efficient O2 use with a higher phosphorylation efficiency and lower ROS emission. We showed that brain mitochondria from more hypoxia tolerant sculpins had lower complex I and higher complex II flux capacities compared with less hypoxia tolerant sculpins, but these differences were not related to variation in phosphorylation efficiency (ADP/O) or mitochondrial coupling (respiratory control ratio). The hypoxia tolerant sculpin had higher mitochondrial H2O2 emission per O2 consumed (H2O2/O2) under oligomycin-induced state 4 conditions compared to less hypoxia tolerant sculpin. An in vitro redox challenge experiment revealed species differences in how well mitochondria defend their glutathione redox status when challenged with high levels of reduced glutathione, but the redox challenge elicited the same H2O2/O2 in all species. Furthermore, in vitro anoxia-recovery lowered absolute H2O2 emission (H2O2/mg mitochondrial protein) in all species and negatively impacted state 3 respiration rates in some species, but the responses were not related to hypoxia tolerance. Overall, we clearly demonstrate a relationship between hypoxia tolerance and complex I and II flux capacities in sculpins, but the differences in complex flux capacity do not appear to be directly related to variation in ROS metabolism.
Collapse
Affiliation(s)
- Gigi Y. Lau
- Department of Zoology, The University of British Columbia, 6270 University Boulevard, Vancouver, B.C., Canada, V6T 1Z4
| | - Jeffrey G. Richards
- Department of Zoology, The University of British Columbia, 6270 University Boulevard, Vancouver, B.C., Canada, V6T 1Z4
| |
Collapse
|
21
|
Vasin MV, Ushakov IB, Bukhtiyarov IV. Stress Reaction and Biochemical Shock as Interrelated and Unavoidable Components in the Formation of High Radioresistance of the Body in Acute Hypoxia. BIOL BULL+ 2018. [DOI: 10.1134/s1062359017060115] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
22
|
Mitochondrial permeability transition pore: sensitivity to opening and mechanistic dependence on substrate availability. Sci Rep 2017; 7:10492. [PMID: 28874733 PMCID: PMC5585167 DOI: 10.1038/s41598-017-10673-8] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 08/11/2017] [Indexed: 12/14/2022] Open
Abstract
Mitochondrial Ca2+ uptake has a key role in cellular Ca2+ homeostasis. Excessive matrix Ca2+ concentrations, especially when coincident with oxidative stress, precipitate opening of an inner mitochondrial membrane, high-conductance channel: the mitochondrial permeability transition pore (mPTP). mPTP opening has been implicated as a final cell death pathway in numerous diseases and therefore understanding conditions dictating mPTP opening is crucial for developing targeted therapies. Here, we have investigated the impact of mitochondrial metabolic state on the probability and consequences of mPTP opening. Isolated mitochondria were energised using NADH- or FADH2-linked substrates. The functional consequences of Ca2+-induced mPTP opening were assessed by Ca2+ retention capacity, using fluorescence-based analysis, and simultaneous measurements of mitochondrial Ca2+ handling, membrane potential, respiratory rate and production of reactive oxygen species (ROS). Succinate-induced, membrane potential-dependent reverse electron transfer sensitised mitochondria to mPTP opening. mPTP-induced depolarisation under succinate subsequently inhibited reverse electron transfer. Complex I-driven respiration was reduced after mPTP opening but sustained in the presence of complex II-linked substrates, consistent with inhibition of complex I-supported respiration by leakage of matrix NADH. Additionally, ROS generated at complex III did not sensitise mitochondria to mPTP opening. Thus, cellular metabolic fluxes and metabolic environment dictate mitochondrial functional response to Ca2+ overload.
Collapse
|
23
|
Golovach NG, Cheshchevik VT, Lapshina EA, Ilyich TV, Zavodnik IB. Calcium-Induced Mitochondrial Permeability Transitions: Parameters of Ca 2+ Ion Interactions with Mitochondria and Effects of Oxidative Agents. J Membr Biol 2017; 250:225-236. [PMID: 28251264 DOI: 10.1007/s00232-017-9953-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 02/21/2017] [Indexed: 12/13/2022]
Abstract
We evaluated the parameters of Ca2+-induced mitochondrial permeability transition (MPT) pore formations, Ca2+ binding constants, stoichiometry, energy of activation, and the effect of oxidative agents, tert-butyl hydroperoxide (tBHP), and hypochlorous acid (HOCl), on Ca2+ -mediated process in rat liver mitochondria. From the Hill plot of the dependence of MPT rate on Ca2+ concentration, we determined the order of interaction of Ca2+ ions with the mitochondrial sites, n = 3, and the apparent Kd = 60 ± 12 µM. We also found the apparent Michaelis-Menten constant, Km, for Ca2+ interactions with mitochondria to be equal to 75 ± 20 µM, whereas that in the presence of 300 µM tBHP was 120 ± 20 µM. Using the Arrhenius plots of the temperature dependences of apparent mitochondrial swelling rate at various Ca2+ concentrations, we calculated the activation energy of the MPT process. ΔEa was 130 ± 20 kJ/mol at temperatures below the break point of the Arrhenius plot (30-34 °C) and 50 ± 9 kJ/mol at higher temperatures. Ca2+ ions induced rapid mitochondrial NADH depletion and membrane depolarization. Prevention of the pore formation by cyclosporin A inhibited Ca2+-dependent mitochondrial depolarization and Mg2+ ions attenuated the potential dissipation. tBHP (10-150 µM) dose-dependently enhanced the rate of MPT opening, whereas the effect of HOCl on MPT depended on the ratio of HOCl/Ca2+. The apparent Km of tBHP interaction with mitochondria in the swelling reaction was found to be Km = 11 ± 3 µM. The present study provides evidence that three calcium ions interact with mitochondrial site with high affinity during MPT. Ca2+-induced MPT pore formations due to mitochondrial membrane protein denaturation resulted in membrane potential dissipation. Oxidants with different mechanisms, tBHP and HOCl, reduced mitochondrial membrane potential and oxidized mitochondrial NADH in EDTA-free medium and had an effect on Ca2+-induced MPT onset.
Collapse
Affiliation(s)
- Nina G Golovach
- Department of Biochemistry, Yanka Kupala State University of Grodno, Blvd. Len. Kom. - 50, 230030, Grodno, Belarus
| | - Vitali T Cheshchevik
- Department of Biochemistry, Yanka Kupala State University of Grodno, Blvd. Len. Kom. - 50, 230030, Grodno, Belarus
| | - Elena A Lapshina
- Department of Biochemistry, Yanka Kupala State University of Grodno, Blvd. Len. Kom. - 50, 230030, Grodno, Belarus
| | - Tatsiana V Ilyich
- Department of Biochemistry, Yanka Kupala State University of Grodno, Blvd. Len. Kom. - 50, 230030, Grodno, Belarus
| | - Ilya B Zavodnik
- Department of Biochemistry, Yanka Kupala State University of Grodno, Blvd. Len. Kom. - 50, 230030, Grodno, Belarus.
| |
Collapse
|
24
|
Koziel A, Jarmuszkiewicz W. Hypoxia and aerobic metabolism adaptations of human endothelial cells. Pflugers Arch 2017; 469:815-827. [PMID: 28176017 PMCID: PMC5438427 DOI: 10.1007/s00424-017-1935-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 01/08/2017] [Accepted: 01/10/2017] [Indexed: 01/09/2023]
Abstract
The goal of our study was to assess the influence of chronic exposure to hypoxia on mitochondrial oxidative metabolism in human umbilical vein endothelial cells (EA.hy926 line) cultured for 6 days at 1% O2 tension. The hypoxia-induced effects were elucidated at the cellular and isolated mitochondria levels. Hypoxia elevated fermentation but did not change mitochondrial biogenesis or the aerobic respiratory capacity of endothelial cells. In endothelial cells, hypoxia caused a general decrease in mitochondrial respiration during carbohydrate, fatty acid, and amino acid oxidation but increased exclusively ketogenic amino acid oxidation. Hypoxia induced an elevation of intracellular and mitochondrial reactive oxygen species (ROS) formation, although cell viability was unchanged and antioxidant systems (superoxide dismutases SOD1 and SOD2, and uncoupling proteins (UCPs)) were not increased. In mitochondria from hypoxic cells, the opposite change was observed at the respiratory chain level, i.e., considerably elevated expression and activity of complex II, and decreased expression and activity of complex I were observed. The elevated activity of complex II resulted in an increase in succinate-sustained mitochondrial ROS formation, mainly through increased reverse electron transport. A hypoxia-induced decrease in UCP2 expression and activity was also observed. It can be concluded that the exposure to chronic hypoxia induces a shift from aerobic toward anaerobic catabolic metabolism. The hypoxia-induced increase in intracellular and mitochondrial ROS formation was not excessive and may be involved in endothelial signaling of hypoxic responses. Our results indicate an important role of succinate, complex II, and reverse electron transport in hypoxia-induced adjustments in endothelial cells.
Collapse
Affiliation(s)
- Agnieszka Koziel
- Department of Bioenergetics, Adam Mickiewicz University, Umultowska 89, 61-614, Poznan, Poland
| | - Wieslawa Jarmuszkiewicz
- Department of Bioenergetics, Adam Mickiewicz University, Umultowska 89, 61-614, Poznan, Poland.
| |
Collapse
|
25
|
Lukyanova LD, Kirova YI. Mitochondria-controlled signaling mechanisms of brain protection in hypoxia. Front Neurosci 2015; 9:320. [PMID: 26483619 PMCID: PMC4589588 DOI: 10.3389/fnins.2015.00320] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 08/27/2015] [Indexed: 01/06/2023] Open
Abstract
The article is focused on the role of the cell bioenergetic apparatus, mitochondria, involved in development of immediate and delayed molecular mechanisms for adaptation to hypoxic stress in brain cortex. Hypoxia induces reprogramming of respiratory chain function and switching from oxidation of NAD-related substrates (complex I) to succinate oxidation (complex II). Transient, reversible, compensatory activation of respiratory chain complex II is a major mechanism of immediate adaptation to hypoxia necessary for (1) succinate-related energy synthesis in the conditions of oxygen deficiency and formation of urgent resistance in the body; (2) succinate-related stabilization of HIF-1α and initiation of its transcriptional activity related with formation of long-term adaptation; (3) succinate-related activation of the succinate-specific receptor, GPR91. This mechanism participates in at least four critical regulatory functions: (1) sensor function related with changes in kinetic properties of complex I and complex II in response to a gradual decrease in ambient oxygen concentration; this function is designed for selection of the most efficient pathway for energy substrate oxidation in hypoxia; (2) compensatory function focused on formation of immediate adaptive responses to hypoxia and hypoxic resistance of the body; (3) transcriptional function focused on activated synthesis of HIF-1 and the genes providing long-term adaptation to low pO2; (4) receptor function, which reflects participation of mitochondria in the intercellular signaling system via the succinate-dependent receptor, GPR91. In all cases, the desired result is achieved by activation of the succinate-dependent oxidation pathway, which allows considering succinate as a signaling molecule. Patterns of mitochondria-controlled activation of GPR-91- and HIF-1-dependent reaction were considered, and a possibility of their participation in cellular-intercellular-systemic interactions in hypoxia and adaptation was proved.
Collapse
Affiliation(s)
- Ludmila D. Lukyanova
- Laboratory for Bioenergetics and Hypoxia, Institute of General Pathology and PathophysiologyMoscow, Russia
| | | |
Collapse
|
26
|
Woitek F, Zentilin L, Hoffman NE, Powers JC, Ottiger I, Parikh S, Kulczycki AM, Hurst M, Ring N, Wang T, Shaikh F, Gross P, Singh H, Kolpakov MA, Linke A, Houser SR, Rizzo V, Sabri A, Madesh M, Giacca M, Recchia FA. Intracoronary Cytoprotective Gene Therapy: A Study of VEGF-B167 in a Pre-Clinical Animal Model of Dilated Cardiomyopathy. J Am Coll Cardiol 2015; 66:139-53. [PMID: 26160630 DOI: 10.1016/j.jacc.2015.04.071] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Revised: 04/24/2015] [Accepted: 04/28/2015] [Indexed: 01/01/2023]
Abstract
BACKGROUND Vascular endothelial growth factor (VEGF)-B activates cytoprotective/antiapoptotic and minimally angiogenic mechanisms via VEGF receptors. Therefore, VEGF-B might be an ideal candidate for the treatment of dilated cardiomyopathy, which displays modest microvascular rarefaction and increased rate of apoptosis. OBJECTIVES This study evaluated VEGF-B gene therapy in a canine model of tachypacing-induced dilated cardiomyopathy. METHODS Chronically instrumented dogs underwent cardiac tachypacing for 28 days. Adeno-associated virus serotype 9 viral vectors carrying VEGF-B167 genes were infused intracoronarily at the beginning of the pacing protocol or during compensated heart failure. Moreover, we tested a novel VEGF-B167 transgene controlled by the atrial natriuretic factor promoter. RESULTS Compared with control subjects, VEGF-B167 markedly preserved diastolic and contractile function and attenuated ventricular chamber remodeling, halting the progression from compensated to decompensated heart failure. Atrial natriuretic factor-VEGF-B167 expression was low in normally functioning hearts and stimulated by cardiac pacing; it thus functioned as an ideal therapeutic transgene, active only under pathological conditions. CONCLUSIONS Our results, obtained with a standard technique of interventional cardiology in a clinically relevant animal model, support VEGF-B167 gene transfer as an affordable and effective new therapy for nonischemic heart failure.
Collapse
Affiliation(s)
- Felix Woitek
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania; University of Leipzig-Heart Center, Department of Cardiology/Internal Medicine, Leipzig, Germany
| | - Lorena Zentilin
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Nicholas E Hoffman
- Center for Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Jeffery C Powers
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Isabel Ottiger
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania; University of Leipzig-Heart Center, Department of Cardiology/Internal Medicine, Leipzig, Germany
| | - Suraj Parikh
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Anna M Kulczycki
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Marykathryn Hurst
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Nadja Ring
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Tao Wang
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Farah Shaikh
- Center for Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Polina Gross
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Harinder Singh
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Mikhail A Kolpakov
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Axel Linke
- University of Leipzig-Heart Center, Department of Cardiology/Internal Medicine, Leipzig, Germany
| | - Steven R Houser
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Victor Rizzo
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Abdelkarim Sabri
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Muniswamy Madesh
- Center for Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Mauro Giacca
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Fabio A Recchia
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania; Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy.
| |
Collapse
|
27
|
Shanmughapriya S, Rajan S, Hoffman NE, Zhang X, Guo S, Kolesar JE, Hines KJ, Ragheb J, Jog NR, Caricchio R, Baba Y, Zhou Y, Kaufman BA, Cheung JY, Kurosaki T, Gill DL, Madesh M. Ca2+ signals regulate mitochondrial metabolism by stimulating CREB-mediated expression of the mitochondrial Ca2+ uniporter gene MCU. Sci Signal 2015; 8:ra23. [PMID: 25737585 DOI: 10.1126/scisignal.2005673] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Cytosolic Ca2+ signals, generated through the coordinated translocation of Ca2+ across the plasma membrane (PM) and endoplasmic reticulum (ER) membrane, mediate diverse cellular responses. Mitochondrial Ca2+ is important for mitochondrial function, and when cytosolic Ca2+ concentration becomes too high, mitochondria function as cellular Ca2+ sinks. By measuring mitochondrial Ca2+ currents, we found that mitochondrial Ca2+ uptake was reduced in chicken DT40 B lymphocytes lacking either the ER-localized inositol trisphosphate receptor (IP3R), which releases Ca2+ from the ER, or Orai1 or STIM1, components of the PM-localized Ca2+ -permeable channel complex that mediates store-operated calcium entry (SOCE) in response to depletion of ER Ca2+ stores. The abundance of MCU, the pore-forming subunit of the mitochondrial Ca2+ uniporter, was reduced in cells deficient in IP3R, STIM1, or Orai1. Chromatin immunoprecipitation and promoter reporter analyses revealed that the Ca2+ -regulated transcription factor CREB (cyclic adenosine monophosphate response element-binding protein) directly bound the MCU promoter and stimulated expression. Lymphocytes deficient in IP3R, STIM1, or Orai1 exhibited altered mitochondrial metabolism, indicating that Ca2+ released from the ER and SOCE-mediated signals modulates mitochondrial function. Thus, our results showed that a transcriptional regulatory circuit involving Ca2+ -dependent activation of CREB controls the Ca2+ uptake capability of mitochondria and hence regulates mitochondrial metabolism.
Collapse
Affiliation(s)
- Santhanam Shanmughapriya
- Department of Biochemistry, Temple University, Philadelphia, PA 19140, USA. Center for Translational Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Sudarsan Rajan
- Department of Biochemistry, Temple University, Philadelphia, PA 19140, USA. Center for Translational Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Nicholas E Hoffman
- Department of Biochemistry, Temple University, Philadelphia, PA 19140, USA. Center for Translational Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Xueqian Zhang
- Center for Translational Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Shuchi Guo
- Department of Biochemistry, Temple University, Philadelphia, PA 19140, USA. Center for Translational Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Jill E Kolesar
- Department of Animal Biology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA 19104, USA
| | - Kevin J Hines
- Department of Biochemistry, Temple University, Philadelphia, PA 19140, USA. Center for Translational Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Jonathan Ragheb
- Department of Biochemistry, Temple University, Philadelphia, PA 19140, USA. Center for Translational Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Neelakshi R Jog
- Department of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Roberto Caricchio
- Department of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Yoshihiro Baba
- Laboratory of Lymphocyte Differentiation, World Premiere International Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| | - Yandong Zhou
- Department of Cellular and Molecular Physiology, Penn State University College of Medicine, Hershey, PA 17033, USA
| | - Brett A Kaufman
- Department of Animal Biology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA 19104, USA
| | - Joseph Y Cheung
- Center for Translational Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Tomohiro Kurosaki
- Laboratory of Lymphocyte Differentiation, World Premiere International Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| | - Donald L Gill
- Department of Cellular and Molecular Physiology, Penn State University College of Medicine, Hershey, PA 17033, USA.
| | - Muniswamy Madesh
- Department of Biochemistry, Temple University, Philadelphia, PA 19140, USA. Center for Translational Medicine, Temple University, Philadelphia, PA 19140, USA.
| |
Collapse
|
28
|
Essentiality of succinate dehydrogenase in Mycobacterium smegmatis and its role in the generation of the membrane potential under hypoxia. mBio 2014; 5:mBio.01093-14. [PMID: 25118234 PMCID: PMC4145680 DOI: 10.1128/mbio.01093-14] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Succinate:quinone oxidoreductase (Sdh) is a membrane-bound complex that couples the oxidation of succinate to fumarate in the cytoplasm to the reduction of quinone to quinol in the membrane. Mycobacterial species harbor genes for two putative sdh operons, but the individual roles of these two operons are unknown. In this communication, we show that Mycobacterium smegmatis mc2155 expresses two succinate dehydrogenases designated Sdh1 and Sdh2. Sdh1 is encoded by a five-gene operon (MSMEG_0416-MSMEG_0420), and Sdh2 is encoded by a four-gene operon (MSMEG_1672-MSMEG_1669). These two operons are differentially expressed in response to carbon limitation, hypoxia, and fumarate, as monitored by sdh promoter-lacZ fusions. While deletion of the sdh1 operon did not yield any growth phenotypes on succinate or other nonfermentable carbon sources, the sdh2 operon could be deleted only in a merodiploid background, demonstrating that Sdh2 is essential for growth. Sdh activity and succinate-dependent proton pumping were detected in cells grown aerobically, as well as under hypoxia. Fumarate reductase activity was absent under these conditions, indicating that neither Sdh1 nor Sdh2 could catalyze the reverse reaction. Sdh activity was inhibited by the Sdh inhibitor 3-nitroproprionate (3NP), and treatment with 3NP dissipated the membrane potential of wild-type or Δsdh1 mutant cells under hypoxia but not that of cells grown aerobically. These data imply that Sdh2 is the generator of the membrane potential under hypoxia, an essential role for the cell. Complex II or succinate dehydrogenase (Sdh) is a major respiratory enzyme that couples the oxidation of succinate to fumarate in the cytoplasm to the reduction of quinone to quinol in the membrane. Mycobacterial species harbor genes for two putative sdh operons, sdh1 and sdh2, but the individual roles of these two operons are unknown. In this communication, we show that sdh1 and sdh2 are differentially expressed in response to energy limitation, oxygen tension, and alternative electron acceptor availability, suggesting distinct functional cellular roles. Sdh2 was essential for growth and generation of the membrane potential in hypoxic cells. Given the essentiality of succinate dehydrogenase and oxidative phosphorylation in the growth cycle of Mycobacterium tuberculosis, the potential exists to develop new antituberculosis agents against the mycobacterial succinate dehydrogenase. This enzyme has been proposed as a potential target for the development of new chemotherapeutic agents against intracellular parasites and mitochondrion-associated disease.
Collapse
|
29
|
Doonan PJ, Chandramoorthy HC, Hoffman NE, Zhang X, Cárdenas C, Shanmughapriya S, Rajan S, Vallem S, Chen X, Foskett JK, Cheung JY, Houser SR, Madesh M. LETM1-dependent mitochondrial Ca2+ flux modulates cellular bioenergetics and proliferation. FASEB J 2014; 28:4936-49. [PMID: 25077561 DOI: 10.1096/fj.14-256453] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Dysregulation of mitochondrial Ca(2+)-dependent bioenergetics has been implicated in various pathophysiological settings, including neurodegeneration and myocardial infarction. Although mitochondrial Ca(2+) transport has been characterized, and several molecules, including LETM1, have been identified, the functional role of LETM1-mediated Ca(2+) transport remains unresolved. This study examines LETM1-mediated mitochondrial Ca(2+) transport and bioenergetics in multiple cell types, including fibroblasts derived from patients with Wolf-Hirschhorn syndrome (WHS). The results show that both mitochondrial Ca(2+) influx and efflux rates are impaired in LETM1 knockdown, and similar phenotypes were observed in ΔEF hand, (D676A D688K)LETM1 mutant-overexpressed cells, and in cells derived from patients with WHS. Although LETM1 levels were lower in WHS-derived fibroblasts, the mitochondrial Ca(2+) uniporter components MCU, MCUR1, and MICU1 remain unaltered. In addition, the MCU mitoplast patch-clamp current (IMCU) was largely unaffected in LETM1-knockdown cells. Silencing of LETM1 also impaired basal mitochondrial oxygen consumption, possibly via complex IV inactivation and ATP production. Remarkably, LETM1 knockdown also resulted in increased reactive oxygen species production. Further, LETM1 silencing promoted AMPK activation, autophagy, and cell cycle arrest. Reconstitution of LETM1 or antioxidant overexpression rescued mitochondrial Ca(2+) transport and bioenergetics. These findings reveal the role of LETM1-dependent mitochondrial Ca(2+) flux in shaping cellular bioenergetics.
Collapse
Affiliation(s)
| | | | | | | | - César Cárdenas
- Anatomy and Developmental Biology Program, Institute of Biomedical Sciences, University of Chile, Santiago, Chile; and
| | | | - Sudarsan Rajan
- Department of Biochemistry, Center for Translational Medicine
| | - Sandhya Vallem
- Department of Biochemistry, Center for Translational Medicine
| | - Xiongwen Chen
- Cardiovascular Research Center, and Department of Physiology, Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - J Kevin Foskett
- Department of Physiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - Steven R Houser
- Cardiovascular Research Center, and Department of Physiology, Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | | |
Collapse
|
30
|
Bagkos G, Koufopoulos K, Piperi C. A new model for mitochondrial membrane potential production and storage. Med Hypotheses 2014; 83:175-81. [PMID: 24907229 DOI: 10.1016/j.mehy.2014.05.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 05/10/2014] [Indexed: 02/05/2023]
Abstract
Mitochondrial membrane potential (MMP) is the most reliable indicator of mitochondrial function. The MMP value range of -136 to -140mV has been considered optimal for maximum ATP production for all living organisms. Even small changes from the above range result in a large fall in ATP production and a large increase in ROS production. The resulting bioenergetic deregulation is considered as the causative agent for numerous major human diseases. Normalization of MMP value improves mitochondrial function and gives excellent therapeutic results. In order for a systematic effective treatment of these diseases to be developed, a detailed knowledge of the mechanism of MMP production is absolutely necessary. However, despite the long-standing research efforts, a concrete mechanism for MMP production has not been found yet. The present paper proposes a novel mechanism of MMP production based on new considerations underlying the function of the two basic players of MMP production, the electron transport chain (ETC) and the F1F0 ATP synthase. Under normal conditions, MMP is almost exclusively produced by the electron flow through ETC complexes I-IV, creating a direct electric current that stops in subunit II of complex IV and gradually charges MMP. However, upon ETC dysfunction F1F0 ATP synthase reverses its action and starts to hydrolyze ATP. ATP hydrolysis further produces electric energy which is transferred, in the form of a direct electric current, from F1 to F0 where is used to charge MMP. This new model is expected to redirect current experimental research on mitochondrial bioenergetics and indicate new therapeutic schemes for mitochondrial disorders.
Collapse
Affiliation(s)
- Georgios Bagkos
- Department of Biological Chemistry, University of Athens Medical School, Athens, Greece
| | - Kostas Koufopoulos
- Department of Biological Chemistry, University of Athens Medical School, Athens, Greece
| | - Christina Piperi
- Department of Biological Chemistry, University of Athens Medical School, Athens, Greece.
| |
Collapse
|
31
|
Hoffman NE, Chandramoorthy HC, Shanmughapriya S, Zhang XQ, Vallem S, Doonan PJ, Malliankaraman K, Guo S, Rajan S, Elrod JW, Koch WJ, Cheung JY, Madesh M. SLC25A23 augments mitochondrial Ca²⁺ uptake, interacts with MCU, and induces oxidative stress-mediated cell death. Mol Biol Cell 2014; 25:936-47. [PMID: 24430870 PMCID: PMC3952861 DOI: 10.1091/mbc.e13-08-0502] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Emerging findings suggest that two lineages of mitochondrial Ca(2+) uptake participate during active and resting states: 1) the major eukaryotic membrane potential-dependent mitochondrial Ca(2+) uniporter and 2) the evolutionarily conserved exchangers and solute carriers, which are also involved in ion transport. Although the influx of Ca(2+) across the inner mitochondrial membrane maintains metabolic functions and cell death signal transduction, the mechanisms that regulate mitochondrial Ca(2+) accumulation are unclear. Solute carriers--solute carrier 25A23 (SLC25A23), SLC25A24, and SLC25A25--represent a family of EF-hand-containing mitochondrial proteins that transport Mg-ATP/Pi across the inner membrane. RNA interference-mediated knockdown of SLC25A23 but not SLC25A24 and SLC25A25 decreases mitochondrial Ca(2+) uptake and reduces cytosolic Ca(2+) clearance after histamine stimulation. Ectopic expression of SLC25A23 EF-hand-domain mutants exhibits a dominant-negative phenotype of reduced mitochondrial Ca(2+) uptake. In addition, SLC25A23 interacts with mitochondrial Ca(2+) uniporter (MCU; CCDC109A) and MICU1 (CBARA1) while also increasing IMCU. In addition, SLC25A23 knockdown lowers basal mROS accumulation, attenuates oxidant-induced ATP decline, and reduces cell death. Further, reconstitution with short hairpin RNA-insensitive SLC25A23 cDNA restores mitochondrial Ca(2+) uptake and superoxide production. These findings indicate that SLC25A23 plays an important role in mitochondrial matrix Ca(2+) influx.
Collapse
Affiliation(s)
- Nicholas E Hoffman
- Department of Biochemistry, Temple University, Philadelphia, PA 19140 Center for Translational Medicine, Temple University, Philadelphia, PA 19140
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Dehne N, Brüne B. Sensors, transmitters, and targets in mitochondrial oxygen shortage-a hypoxia-inducible factor relay story. Antioxid Redox Signal 2014; 20:339-52. [PMID: 22794181 DOI: 10.1089/ars.2012.4776] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
SIGNIFICANCE Cells sense and respond to a shortage of oxygen by activating the hypoxia-inducible transcription factors HIF-1 and HIF-2 and evoking adaptive responses. RECENT ADVANCES Mitochondria are at the center of a hypoxia sensing and responding relay system. CRITICAL ISSUES Under normoxia, reactive oxygen species (ROS) and nitric oxide (NO) are HIF activators. As their individual flux rates determine their diffusion-controlled interaction, predictions how these radicals affect HIF appear context-dependent. Considering that the oxygen requirement for NO formation limits its role in activating HIF to conditions of ambient oxygen tension. Given the central role of mitochondrial complex IV as a NO target, especially under hypoxia, allows inhibition of mitochondrial respiration by NO to spare oxygen thus, raising the threshold for HIF activation. HIF targets seem to configure a feedback-signaling circuit aimed at gradually adjusting mitochondrial function. In hypoxic cancer cells, mitochondria redirect Krebs cycle intermediates to preserve their biosynthetic ability. Persistent HIF activation lowers the entry of electron-delivering compounds into mitochondria to reduce Krebs cycle fueling and β-oxidation, attenuates the expression of electron transport chain components, limits mitochondria biosynthesis, and provokes their removal by autophagy. FUTURE DIRECTIONS Mitochondria can be placed central in a hypoxia sensing-hypoxia responding circuit. We need to determine to which extent and how mitochondria contribute to sense hypoxia, explore whether modulating their oxygen-consuming capacity redirects hypoxic responses in in vivo relevant disease conditions, and elucidate how the multiple HIF targets in mitochondria shape conditions of acute versus chronic hypoxia.
Collapse
Affiliation(s)
- Nathalie Dehne
- Faculty of Medicine, Institute of Biochemistry I/ZAFES, Goethe-University Frankfurt , Frankfurt, Germany
| | | |
Collapse
|
33
|
Mills E, O'Neill LAJ. Succinate: a metabolic signal in inflammation. Trends Cell Biol 2013; 24:313-20. [PMID: 24361092 DOI: 10.1016/j.tcb.2013.11.008] [Citation(s) in RCA: 451] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 11/20/2013] [Accepted: 11/22/2013] [Indexed: 11/26/2022]
Abstract
Succinate is an intermediate of the tricarboxylic acid (TCA) cycle, and plays a crucial role in adenosine triphosphate (ATP) generation in mitochondria. Recently, new roles for succinate outside metabolism have emerged. Succinate stabilizes the transcription factor hypoxia-inducible factor-1α (HIF-1α) in specific tumors and in activated macrophages, and stimulates dendritic cells via its receptor succinate receptor 1. Furthermore, succinate has been shown to post-translationally modify proteins. This expanding repertoire of functions for succinate suggests a broader role in cellular activation. We review the new roles of succinate and draw parallels to other metabolites such as NAD(+) and citrate whose roles have expanded beyond metabolism and into signaling.
Collapse
Affiliation(s)
- Evanna Mills
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Luke A J O'Neill
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.
| |
Collapse
|
34
|
Deficiency of the complex I of the mitochondrial respiratory chain but improved adenylate control over succinate-dependent respiration are human gastric cancer-specific phenomena. Mol Cell Biochem 2012; 370:69-78. [PMID: 22821176 DOI: 10.1007/s11010-012-1399-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 07/07/2012] [Indexed: 12/13/2022]
Abstract
The purpose of study was to comparatively characterize the oxidative phosphorylation (OXPHOS) and function of respiratory chain in mitochondria in human gastric corpus mucosa undergoing transition from normal to cancer states and in human gastric cancer cell lines, MKN28 and MKN45. The tissue samples taken by endobiopsy and the cells were permeabilized by saponin treatment to assess mitochondrial function in situ by high-resolution oxygraphy. Compared to the control group of endobiopsy samples, the maximal capacity of OXPHOS in the cancer group was almost twice lower. The respiratory chain complex I-dependent respiration, normalized to complex II-dependent respiration, was reduced that suggests deficiency of complex I, but the respiratory control by ADP in the presence of succinate was increased. Similar changes were observed also in mucosa adjacent to cancer tissue. The respiratory capacity of MKN45 cells was higher than that of MKN28 cells, but both types of cells exhibited a deficiency of complex I of the respiratory chain which appears to be an intrinsic property of the cancer cells. In conclusion, human gastric cancer is associated with decreased respiratory capacity, deficiency of the respiratory complex I of mitochondria, and improved coupling of succinate oxidation to phosphorylation in tumor tissue and adjacent atrophic mucosa. Detection of these changes in endobiopsy samples may be of diagnostic value.
Collapse
|
35
|
Zheng J, Chen LL, Zhang HH, Hu X, Kong W, Hu D. Resveratrol improves insulin resistance of catch-up growth by increasing mitochondrial complexes and antioxidant function in skeletal muscle. Metabolism 2012; 61:954-65. [PMID: 22209670 DOI: 10.1016/j.metabol.2011.11.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 11/04/2011] [Accepted: 11/05/2011] [Indexed: 11/15/2022]
Abstract
Caloric restriction followed by refeeding, a phenomenon known as catch-up growth (CUG), affects mitochondrial function and results in systemic insulin resistance (IR). We investigated the potential of resveratrol (RES) in CUG to prevent IR by increasing activity of the mitochondrial respiratory chain and antioxidant enzymes in skeletal muscle. Rats (8 weeks of age) were divided into 3 groups: normal chow, CUG, and CUG with RES intervention. Skeletal muscle and systemic IR were measured in each group after 4 and 8 weeks. Mitochondrial biogenesis and function, oxidative stress levels, and antioxidant enzyme activity in skeletal muscle were assessed. Catch-up growth-induced IR resulted in significant reductions in both average glucose infusion rate(60-120) at euglycemia and skeletal muscle glucose uptake. Mitochondrial citrate synthase activity was lower; and the activity of complexes I to IV in the intermyofibrillar and subsarcolemmal (SS) mitochondria were reduced by 20% to 40%, with the decrease being more pronounced in the SS fraction. Reactive oxygen species levels were significantly higher in intermyofibrillar and SS mitochondria, whereas activities of antioxidant enzymes were decreased. Oral administration of RES, however, increased silent information regulator 1 activity and improved mitochondrial number and insulin sensitivity. Resveratrol treatment decreased levels of reactive oxygen species and restored activities of antioxidant enzymes. This study demonstrates that RES protects insulin sensitivity of skeletal muscle by improving activities of mitochondrial complexes and antioxidant defense status in CUG rats. Thus, RES has therapeutic potential for preventing CUG-related metabolic disorders.
Collapse
Affiliation(s)
- Juan Zheng
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | | | | | | | | | | |
Collapse
|
36
|
Dong LF, Jameson VJA, Tilly D, Cerny J, Mahdavian E, Marín-Hernández A, Hernández-Esquivel L, Rodríguez-Enríquez S, Stursa J, Witting PK, Stantic B, Rohlena J, Truksa J, Kluckova K, Dyason JC, Ledvina M, Salvatore BA, Moreno-Sánchez R, Coster MJ, Ralph SJ, Smith RAJ, Neuzil J. Mitochondrial targeting of vitamin E succinate enhances its pro-apoptotic and anti-cancer activity via mitochondrial complex II. J Biol Chem 2011; 286:3717-28. [PMID: 21059645 PMCID: PMC3030374 DOI: 10.1074/jbc.m110.186643] [Citation(s) in RCA: 152] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 10/28/2010] [Indexed: 12/27/2022] Open
Abstract
Mitochondrial complex II (CII) has been recently identified as a novel target for anti-cancer drugs. Mitochondrially targeted vitamin E succinate (MitoVES) is modified so that it is preferentially localized to mitochondria, greatly enhancing its pro-apoptotic and anti-cancer activity. Using genetically manipulated cells, MitoVES caused apoptosis and generation of reactive oxygen species (ROS) in CII-proficient malignant cells but not their CII-dysfunctional counterparts. MitoVES inhibited the succinate dehydrogenase (SDH) activity of CII with IC(50) of 80 μM, whereas the electron transfer from CII to CIII was inhibited with IC(50) of 1.5 μM. The agent had no effect either on the enzymatic activity of CI or on electron transfer from CI to CIII. Over 24 h, MitoVES caused stabilization of the oxygen-dependent destruction domain of HIF1α fused to GFP, indicating promotion of the state of pseudohypoxia. Molecular modeling predicted the succinyl group anchored into the proximal CII ubiquinone (UbQ)-binding site and successively reduced interaction energies for serially shorter phytyl chain homologs of MitoVES correlated with their lower effects on apoptosis induction, ROS generation, and SDH activity. Mutation of the UbQ-binding Ser(68) within the proximal site of the CII SDHC subunit (S68A or S68L) suppressed both ROS generation and apoptosis induction by MitoVES. In vivo studies indicated that MitoVES also acts by causing pseudohypoxia in the context of tumor suppression. We propose that mitochondrial targeting of VES with an 11-carbon chain localizes the agent into an ideal position across the interface of the mitochondrial inner membrane and matrix, optimizing its biological effects as an anti-cancer drug.
Collapse
Affiliation(s)
| | | | - David Tilly
- the Eskitis Institute for Cell and Molecular Therapies, Griffith University, Nathan 4111, Queensland, Australia
| | | | - Elahe Mahdavian
- the Department of Chemistry and Physics, Louisiana State University, Shreveport, Louisiana 71115
| | - Alvaro Marín-Hernández
- the Department of Biochemistry, National Institute of Cardiology, Mexico City 14080, Mexico, and
| | - Luz Hernández-Esquivel
- the Department of Biochemistry, National Institute of Cardiology, Mexico City 14080, Mexico, and
| | - Sara Rodríguez-Enríquez
- the Department of Biochemistry, National Institute of Cardiology, Mexico City 14080, Mexico, and
| | - Jan Stursa
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague 14220, Czech Republic
| | - Paul K. Witting
- the Discipline of Pathology, Bosch Research Institute, Sydney Medical School, University of Sydney, Sydney 2006, New South Wales, Australia
| | - Bela Stantic
- Institute for Integrated and Intelligent Systems, and
| | | | | | | | - Jeffrey C. Dyason
- Institute for Glycomics, Griffith University, Southport 4222, Queensland, Australia
| | - Miroslav Ledvina
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague 14220, Czech Republic
| | - Brian A. Salvatore
- the Department of Chemistry and Physics, Louisiana State University, Shreveport, Louisiana 71115
| | - Rafael Moreno-Sánchez
- the Department of Biochemistry, National Institute of Cardiology, Mexico City 14080, Mexico, and
| | - Mark J. Coster
- the Eskitis Institute for Cell and Molecular Therapies, Griffith University, Nathan 4111, Queensland, Australia
| | | | - Robin A. J. Smith
- the Department of Chemistry, University of Otago, Dunedin 9016, New Zealand
| | - Jiri Neuzil
- From the School of Medical Science
- Institute for Glycomics, Griffith University, Southport 4222, Queensland, Australia
| |
Collapse
|