149 results on '"Anatoly A. Starkov"'
Search Results
2. p62-Nrf2-p62 Mitophagy Regulatory Loop as a Target for Preventive Therapy of Neurodegenerative Diseases
- Author
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Artem P. Gureev, Irina S. Sadovnikova, Natalia N. Starkov, Anatoly A. Starkov, and Vasily N. Popov
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mitochondria ,Nrf2 ,p62 ,mitophagy ,regulatory loop ,neurodegenerative disease ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Turnover of the mitochondrial pool due to coordinated processes of mitochondrial biogenesis and mitophagy is an important process in maintaining mitochondrial stability. An important role in this process is played by the Nrf2/ARE signaling pathway, which is involved in the regulation of the expression of genes responsible for oxidative stress protection, regulation of mitochondrial biogenesis, and mitophagy. The p62 protein is a multifunctional cytoplasmic protein that functions as a selective mitophagy receptor for the degradation of ubiquitinated substrates. There is evidence that p62 can positively regulate Nrf2 by binding to its negative regulator, Keap1. However, there is also strong evidence that Nrf2 up-regulates p62 expression. Thereby, a regulatory loop is formed between two important signaling pathways, which may be an important target for drugs aimed at treating neurodegeneration. Constitutive activation of p62 in parallel with Nrf2 would most likely result in the activation of mTORC1-mediated signaling pathways that are associated with the development of malignant neoplasms. The purpose of this review is to describe the p62-Nrf2-p62 regulatory loop and to evaluate its role in the regulation of mitophagy under various physiological conditions.
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- 2020
- Full Text
- View/download PDF
3. Mice deficient in dihydrolipoyl succinyl transferase show increased vulnerability to mitochondrial toxins
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Lichuan Yang, Qingli Shi, Daniel J. Ho, Anatoly A. Starkov, Elizabeth J. Wille, Hui Xu, H.L. Chen, Steven Zhang, Cliona M. Stack, Noel Y. Calingasan, Gary E. Gibson, and M. Flint Beal
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Mitochondria ,Neurodegenerative diseases ,Parkinson ,Huntington ,Oxidative damage ,α-ketoglutarate dehydrogenase complex ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
The activity of a key mitochondrial tricarboxylic acid cycle enzyme, α-ketoglutarate dehydrogenase complex (KGDHC), declines in many neurodegenerative diseases. KGDHC consists of three subunits. The dihydrolipoyl succinyl transferase (DLST) component is unique to KGDHC. DLST+/− mice showed reduced mRNA and protein levels and decreased brain mitochondrial KGDHC activity. Neurotoxic effects of mitochondrial toxins were exacerbated in DLST+/− mice. MPTP produced a significantly greater reduction of striatal dopamine and tyrosine hydroxylase-positive neurons in the substantia nigra pars compacta of DLST+/− mice. DLST deficiency enhanced the severity of lipid peroxidation in the substantia nigra after MPTP treatment. Striatal lesions induced by either malonate or 3-nitropropionic acid (3-NP) were significantly larger in DLST+/− mice than in wildtype controls. DLST deficiency enhanced the 3-NP inhibition of mitochondria enzymes, and 3-NP induced protein and DNA oxidations. These observations support the hypothesis that reductions in KGDHC may impair the adaptability of the brain and contribute to the pathogenesis of neurodegenerative diseases.
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- 2009
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4. Promethazine protects against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine neurotoxicity
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Carine Cleren, Anatoly A. Starkov, Noel Y. Calingasan, Beverly J. Lorenzo, Junya Chen, and M. Flint Beal
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Promethazine ,MPTP ,MPP+ ,Parkinson ,Neuroprotection ,Mitochondria ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Promethazine (PMZ) is an FDA-approved antihistaminergic drug that was identified as a potentially neuroprotective compound in the NINDS screening program. PMZ accumulates in brain mitochondria in vivo and inhibits Ca2+-induced mitochondrial permeability transition pore (PTP) in rat liver mitochondria in vitro. We hypothesized that PMZ may have a protective effect in a mitochondrial toxin model of Parkinson's disease (PD). Mice treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) sustained a significant loss of dopaminergic neurons within the SNpc that was strongly attenuated by PMZ treatment. However, neither striatal MPP+ concentrations nor MPTP-induced inhibition of mitochondrial complex I were affected by PMZ treatment. In isolated mouse brain mitochondria, PMZ partially prevented and reversed MPP+-induced depolarization of membrane potential and inhibited the Ca2+-induced PTP in brain mitochondria. The sum of data indicates that PMZ is a strong neuroprotective agent capable of protecting dopaminergic neurons against MPTP toxicity in vivo.
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- 2005
- Full Text
- View/download PDF
5. Metabolic ROS Signaling: To Immunity and Beyond
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A. Y. Andreyev, Anatoly A. Starkov, Yulia Kushnareva, and Natalia N. Starkova
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Mitochondrial ROS ,mitochondrial biogenesis ,Bioenergetics ,immunometabolism ,T cells ,Context (language use) ,Review ,Mitochondrion ,Biology ,medicine.disease_cause ,Biochemistry ,03 medical and health sciences ,medicine ,Animals ,Humans ,glycolytic switch ,chemistry.chemical_classification ,reactive oxygen species ,0303 health sciences ,Reactive oxygen species ,030302 biochemistry & molecular biology ,General Medicine ,Mitochondria ,Cell biology ,macrophages ,Oxidative Stress ,Metabolic pathway ,Mitochondrial biogenesis ,chemistry ,Immune System ,Energy Metabolism ,Oxidative stress ,Signal Transduction - Abstract
Metabolism is a critical determinant of immune cell functionality. Immunometabolism, by definition, is a multidisciplinary area of immunology research that integrates the knowledge of energy transduction mechanisms and biochemical pathways. An important concept in the field is metabolic switch, a transition of immune cells upon activation to preferential utilization of select catabolic pathways for their energy needs. Mitochondria are not inert in this process and contribute to the metabolic adaptation by different mechanisms which include increasing ATP production to match dynamic bioenergetic demands and serving as a signaling platform. The latter involves generation of reactive oxygen species (ROS), one of the most intensively studied mitochondrial processes. While the role of mitochondrial ROS in the context of oxidative stress is well established, ROS signaling in immunity is an emerging and quickly changing field. In this review, we discuss ROS signaling and immunometabolism concepts from the standpoint of bioenergetics. We also provide a critical insight into the methodology for ROS assessment, outlining current challenges in the field. Finally, based on our analysis of the literature data, we hypothesize that regulatory ROS production, as opposed to oxidative stress, is controlled by mitochondrial biogenesis rather than metabolic switches.
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- 2020
6. Author response: HIF1α stabilization in hypoxia is not oxidant-initiated
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Rajiv R. Ratan, Manisha Vaish, Ian R. Sweet, Anatoly A. Starkov, Amit Kumar, Sheng Zhang, Irina G. Gazaryan, John T. Pinto, Saravanan S. Karuppagounder, John W. Cave, Elizabeth T Anderson, Wang Wang, and Austin M. Rountree
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Chemistry ,medicine ,Pharmacology ,Hypoxia (medical) ,medicine.symptom - Published
- 2021
7. Methylene blue does not bypass Complex <scp>III</scp> antimycin block in mouse brain mitochondria
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Anatoly A. Starkov, Ekaterina A. Shaforostova, Artem P. Gureev, and Vasily N. Popov
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Male ,Biophysics ,Antimycin A ,Blood–brain barrier ,Biochemistry ,Article ,Electron Transport ,Electron Transport Complex III ,Mice ,chemistry.chemical_compound ,Structural Biology ,Genetics ,medicine ,Animals ,Molecular Biology ,Membrane potential ,biology ,Chemistry ,Cytochrome c ,Brain ,Hydrogen Peroxide ,Cell Biology ,Rotenone ,Prodrug ,Electron transport chain ,Mitochondria ,Methylene Blue ,Mice, Inbred C57BL ,medicine.anatomical_structure ,Blood-Brain Barrier ,Coenzyme Q – cytochrome c reductase ,biology.protein ,Female ,Methylene blue - Abstract
Methylene blue (MB) is a promising prodrug to treat mitochondrial dysfunctions that is currently being used in clinical trials for Alzheimer’s disease. MB can penetrate the blood brain barrier, accumulating in brain mitochondria where it acts as a redox mediator in the electron transfer chain (ETC). Mitochondrial flavins are thought to reduce MB, which is then oxidized by cytochrome c, thereby bypassing inhibited Complex I of ETC. We found that in mouse brain mitochondria, MB fails to restore the membrane potential and respiration inhibited by antimycin. Furthermore, antimycin inhibits MB-induced H(2)O(2) generation. Our data suggest that the acceptor of electrons from MB is a Qo ubiquinol-binding site of Complex III; thus, MB-based drugs might not be helpful in mitochondrial dysfunctions involving Complex III inhibition.
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- 2019
8. p62-Nrf2-p62 Mitophagy Regulatory Loop as a Target for Preventive Therapy of Neurodegenerative Diseases
- Author
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Vasily N. Popov, Anatoly A. Starkov, Natalia N Starkov, Irina S. Sadovnikova, and Artem P. Gureev
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Review ,Mitochondrion ,Biology ,Nrf2 ,lcsh:RC321-571 ,03 medical and health sciences ,0302 clinical medicine ,neurodegenerative disease ,Ubiquitin ,Mitophagy ,medicine ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,Gene ,030304 developmental biology ,0303 health sciences ,General Neuroscience ,Neurodegeneration ,p62 ,respiratory system ,medicine.disease ,KEAP1 ,Cell biology ,mitochondria ,mitophagy ,Mitochondrial biogenesis ,biology.protein ,Signal transduction ,regulatory loop ,030217 neurology & neurosurgery - Abstract
Turnover of the mitochondrial pool due to coordinated processes of mitochondrial biogenesis and mitophagy is an important process in maintaining mitochondrial stability. An important role in this process is played by the Nrf2/ARE signaling pathway, which is involved in the regulation of the expression of genes responsible for oxidative stress protection, regulation of mitochondrial biogenesis, and mitophagy. The p62 protein is a multifunctional cytoplasmic protein that functions as a selective mitophagy receptor for the degradation of ubiquitinated substrates. There is evidence that p62 can positively regulate Nrf2 by binding to its negative regulator, Keap1. However, there is also strong evidence that Nrf2 up-regulates p62 expression. Thereby, a regulatory loop is formed between two important signaling pathways, which may be an important target for drugs aimed at treating neurodegeneration. Constitutive activation of p62 in parallel with Nrf2 would most likely result in the activation of mTORC1-mediated signaling pathways that are associated with the development of malignant neoplasms. The purpose of this review is to describe the p62-Nrf2-p62 regulatory loop and to evaluate its role in the regulation of mitophagy under various physiological conditions.
- Published
- 2020
9. Oxidants are dispensable for HIF1α stability in hypoxia
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Irina G. Gazaryan, Austin M. Rountree, Ian R. Sweet, John W. Cave, Elizabeth T Anderson, John T. Pinto, Anatoly A. Starkov, Amit Kumar, Sheng Zhang, Saravanan S. Karuppagounder, Weisheng Wang, Manisha Vaish, and Rajiv R. Ratan
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chemistry.chemical_classification ,Reactive oxygen species ,Antioxidant ,Chemistry ,Superoxide ,medicine.medical_treatment ,Glutathione ,Mitochondrion ,Hypoxia (medical) ,Peroxide ,Cell biology ,Cytosol ,chemistry.chemical_compound ,medicine ,medicine.symptom - Abstract
Hypoxic adaptation mediated by HIF transcription factors has been shown to require mitochondria. Current models suggest that mitochondria regulate oxygen sensor (HIF prolyl hydroxylase) activity and HIF1α stability during hypoxia by either increasing mitochondrial peroxide as a second messenger or by serving as oxygen consumers that enhance the kinetics of cytoplasmic oxygen reduction. Here, we address the role of mitochondrial peroxide specifically in regulating HIF1α stability. We use state-of-the-art tools to evaluate the role of peroxide and other reactive oxygen species (ROS) in regulating HIF1α stability. We show that antioxidant enzymes are not homeostatically induced nor are peroxide levels increased in hypoxia. Forced expression of diverse antioxidant enzymes, all of which diminish peroxide, had disparate effects on HIF1α protein stability. Reduction of lipid peroxides by glutathione peroxidase-4 or superoxide by mitochondrial SOD failed to influence HIF1α protein stability. These data showed that mitochondrial, cytosolic and lipid ROS are dispensable for HIF1α stability and should affirm therapeutic efforts to activate the HIF pathway in disease states by HIF prolyl hydroxylase inhibition.
- Published
- 2020
10. Prohibitin is a positive modulator of mitochondrial function in PC12 cells under oxidative stress
- Author
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Anatoly A. Starkov, Liping Qian, Corey Anderson, Anja Kahl, Ping Zhou, Anna Stepanova, Giovanni Manfredi, and Costantino Iadecola
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0301 basic medicine ,Time Factors ,Cardiolipins ,Cell Survival ,Respiratory chain ,macromolecular substances ,Mitochondrion ,Transfection ,medicine.disease_cause ,PC12 Cells ,Biochemistry ,Neuroprotection ,Article ,Mice ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,Oxygen Consumption ,0302 clinical medicine ,Prohibitins ,Cardiolipin ,medicine ,Animals ,Humans ,Respiratory function ,Viability assay ,Enzyme Inhibitors ,RNA, Small Interfering ,Prohibitin ,Cells, Cultured ,Neurons ,Dose-Response Relationship, Drug ,technology, industry, and agriculture ,Hydrogen Peroxide ,Embryo, Mammalian ,Oxidants ,Mitochondria ,Rats ,Cell biology ,Mice, Inbred C57BL ,Repressor Proteins ,Oxidative Stress ,030104 developmental biology ,Electron Transport Chain Complex Proteins ,chemistry ,Oligomycins ,lipids (amino acids, peptides, and proteins) ,030217 neurology & neurosurgery ,Oxidative stress - Abstract
Prohibitin (PHB) is a ubiquitously expressed and evolutionarily conserved mitochondrial protein with multiple functions. We have recently shown that PHB up-regulation offers robust protection against neuronal injury in models of cerebral ischemia in vitro and in vivo, but the mechanism by which PHB affords neuroprotection remains to be elucidated. Here, we manipulated PHB expression in PC12 neural cells to investigate its impact on mitochondrial function and the mechanisms whereby it protects cells exposed to oxidative stress. PHB over-expression promoted cell survival, whereas PHB down-regulation diminished cell viability. Functionally, manipulation of PHB levels did not affect basal mitochondrial respiration, but it increased spare respiratory capacity. Moreover, PHB over-expression preserved mitochondrial respiratory function of cells exposed to oxidative stress. Preserved respiratory capacity in differentiated PHB over-expressing cells exposed to oxidative stress was associated with an elongated mitochondrial morphology, whereas PHB down-regulation enhanced fragmentation. Mitochondrial complex I oxidative degradation was attenuated by PHB over-expression and increased in PHB knockdown cells. Changes in complex I degradation were associated with alterations of respiratory chain supercomplexes. Furthermore, we showed that PHB directly interacts with cardiolipin and that down-regulation of PHB results in loss of cardiolipin in mitochondria, which may contribute to destabilizing respiratory chain supercomplexes. Taken together, these data demonstrate that PHB modulates mitochondrial integrity and bioenergetics under oxidative stress, and suggest that the protective effect of PHB is mediated by stabilization of the mitochondrial respiratory machinery and its functional capacity, by the regulation of cardiolipin content. Open Data: Materials are available on https://cos.io/our-services/open-science-badges/ https://osf.io/93n6m/.
- Published
- 2018
11. STUDY OF THE MICROBIOLOGICAL COMPOSITION OF DAIRY PRODUCTS AND MAYONNAISE USING DNA BARCODING AND METABARCODING
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Anatoly A. Starkov, Vasily N. Popov, O. V. Savinkova, Mikhail Y. Syromyatnikov, M.Y. Grabovich, A.V. Panevina, Sergey A. Solodskikh, M.V. Orlova, and Anastasia V. Kokina
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0301 basic medicine ,biology ,Bacteria ,lcsh:TP368-456 ,spoilage ,Food spoilage ,fungi ,eukaryotic microorganisms ,Microbial contamination ,biology.organism_classification ,DNA barcoding ,DNA metabarcoding ,food products ,03 medical and health sciences ,lcsh:Food processing and manufacture ,030104 developmental biology ,Milk products ,Food products ,Composition (visual arts) ,Food science ,seeding ,Food Science - Abstract
Prokaryotic and eukaryotic microorganisms cause spoilage of produced dairy and fat-and-oil products. In addition, these products can be contaminated with pathogenic microorganisms. The standard practice of detecting bacterial pathogens is based on the cultivation of microorganisms due to which the analysis lasts from 5 to 7 days. Molecular genetic methods can reduce the analysis time to 1-2 days. In this paper, the ready-made commercial products of the dairy and fat-and-oil industry have been analyzed for the microbiological composition using classical DNA barcoding and DNA metabarcoding. During the study, representatives of the genera Pseudomonas , Bacillus , Lactococcus , Kocuria , Staphylococcus , Moraxella , Paucisalibacillus, Acinetobacter , Klebsiella , Paenibacillus , Lysinibacillus , Enterobacter, Acetobacter and Massilia have been defined . When analyzing the quantitative ratio of microorganisms, it was revealed that dairy and fat-and-oil products are most often seeded with Bacillus sp., among which Bacillus licheniformis (16.67% of colonies) and Bacillus subtilis (11.4% of colonies) can be distinguished . Among Pseudomonas sp. , Pseudomonas fluorescens (19.3% of colonies) are the most numerous . Lactococcus lactis , Acetobacter indonesiensis and Moraxella osloensis bacteria also significantly contaminate dairy and fat-and-oil products . Mayonnaise is contaminated with yeast of the Pichia genus. The analysis revealed opportunistic pathogenic species: Staphylococcus warneri , Staphylococcus epidermidis, Klebsiella pneumonia , Bacillus cereus, Vibrio sp . The presented method for detecting microbial contamination using an Ion torrent PGM platform seems promising for the rapid testing of the produced dairy and fat-and-oil products.
- Published
- 2018
12. Benfotiamine treatment activates the Nrf2/ARE pathway and is neuroprotective in a transgenic mouse model of tauopathy
- Author
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Julie Vignisse, Bobby Thomas, Natalia N. Starkova, Lucien Bettendorff, Meri Gerges, Flint Beal, Manuj Ahuja, Cliona Stack, Ceyhan Elipenahli, Irina G. Gazaryan, N. A. Smirnova, Magali Dumont, Anatoly A. Starkov, Gary E. Gibson, Shari Jainuddin, Victor Tapias, Sushama Wakade, Navneet Ammal Kaidery, Hui Xu, D. M. Hushpulian, and Noel Y. Calingasan
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0301 basic medicine ,Genetically modified mouse ,NF-E2-Related Factor 2 ,Amyloid beta ,Mice, Transgenic ,tau Proteins ,Pharmacology ,Biology ,Protein Aggregation, Pathological ,Neuroprotection ,Progressive supranuclear palsy ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Genetics ,medicine ,Amyloid precursor protein ,Animals ,Humans ,Thiamine ,Molecular Biology ,Genetics (clinical) ,Amyloid beta-Peptides ,Kelch-Like ECH-Associated Protein 1 ,Brain ,General Medicine ,medicine.disease ,Antioxidant Response Elements ,Disease Models, Animal ,Oxidative Stress ,030104 developmental biology ,Benfotiamine ,Tauopathies ,biology.protein ,Original Article ,Tauopathy ,030217 neurology & neurosurgery ,Signal Transduction ,medicine.drug - Abstract
Impaired glucose metabolism, decreased levels of thiamine and its phosphate esters, and reduced activity of thiamine-dependent enzymes, such as pyruvate dehydrogenase, alpha-ketoglutarate dehydrogenase and transketolase occur in Alzheimer’s disease (AD). Thiamine deficiency exacerbates amyloid beta (Aβ) deposition, tau hyperphosphorylation and oxidative stress. Benfotiamine (BFT) rescued cognitive deficits and reduced Aβ burden in amyloid precursor protein (APP)/PS1 mice. In this study, we examined whether BFT confers neuroprotection against tau phosphorylation and the generation of neurofibrillary tangles (NFTs) in the P301S mouse model of tauopathy. Chronic dietary treatment with BFT increased lifespan, improved behavior, reduced glycated tau, decreased NFTs and prevented death of motor neurons. BFT administration significantly ameliorated mitochondrial dysfunction and attenuated oxidative damage and inflammation. We found that BFT and its metabolites (but not thiamine) trigger the expression of Nrf2/antioxidant response element (ARE)-dependent genes in mouse brain as well as in wild-type but not Nrf2-deficient fibroblasts. Active metabolites were more potent in activating the Nrf2 target genes than the parent molecule BFT. Docking studies showed that BFT and its metabolites (but not thiamine) bind to Keap1 with high affinity. These findings demonstrate that BFT activates the Nrf2/ARE pathway and is a promising therapeutic agent for the treatment of diseases with tau pathology, such as AD, frontotemporal dementia and progressive supranuclear palsy.
- Published
- 2018
13. Mildronate protects heart mtDNA from oxidative stress toxicity induced by exhaustive physical exercise
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Artem P. Gureev, Vasily N. Popov, Ekaterina A. Shaforostova, Anatoly A. Starkov, and Irina S. Sadovnikova
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Male ,0301 basic medicine ,Antioxidant ,medicine.medical_treatment ,Biophysics ,Physical exercise ,Pharmacology ,Mitochondrion ,medicine.disease_cause ,DNA, Mitochondrial ,Biochemistry ,Antioxidants ,Mitochondria, Heart ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,Physical Conditioning, Animal ,Animals ,Medicine ,Molecular Biology ,030102 biochemistry & molecular biology ,business.industry ,Glucose transporter ,Glutathione ,Oxidative Stress ,030104 developmental biology ,Mitochondrial biogenesis ,chemistry ,Cytoprotection ,Toxicity ,business ,Oxidative stress ,Methylhydrazines - Abstract
Exhaustive physical exercises are potentially dangerous for human's physical health and may lead to chronic heart disease. Therefore, individuals involved in such activity require effective and safe cardioprotectors. The goal of this research was to study Mildronate (a cardioprotective drug) effect on the level of oxidative stress markers in hearts of mice under conditions of exhausting physical exercise, such as forced swimming for 1 h per day for 7 days. Forced swimming lead to mtDNA damage accumulation, increase in diene conjugates level and loss of reduced glutathione despite an increase in antioxidant genes expression and activation of mitochondrial biogenesis. Mildronate treatment reduced oxidative stress, probably due to the inhibition of fatty acids transport to mitochondria and an increase in the intensity of glucose oxidation, which in part confirms by increase in glucose transporter expression. Thus, we can assume that Mildronate is an effective cardioprotector in exhaustive physical exercises.
- Published
- 2021
14. Mild metabolic perturbations alter succinylation of mitochondrial proteins
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Travis T. Denton, Samuel Potash, Vsevolod V. Belousov, Dmitry S. Bilan, Anatoly A. Starkov, Huan-Lian Chen, Gary E. Gibson, and Hui Xu
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0301 basic medicine ,SIRT5 ,Oligomycin ,Organophosphonates ,Succinic Acid ,Oxidative phosphorylation ,Deoxyglucose ,Article ,Oxidative Phosphorylation ,Mitochondrial Proteins ,Mice ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,Succinylation ,0302 clinical medicine ,Cell Line, Tumor ,Animals ,Glycolysis ,Chemistry ,organic chemicals ,Succinates ,Metabolism ,NAD ,Citric acid cycle ,030104 developmental biology ,Biochemistry ,bacteria ,NAD+ kinase ,Oxidation-Reduction ,030217 neurology & neurosurgery - Abstract
Succinylation of proteins is widespread, modifies both the charge and size of the molecules, and can alter their function. For example, liver mitochondrial proteins have 1,190 unique succinylation sites representing multiple metabolic pathways. Succinylation is sensitive to both increases and decreases of the NAD+ -dependent desuccinylase, SIRT5. Although the succinyl group for succinylation is derived from metabolism, the effects of systematic variation of metabolism on mitochondrial succinylation are not known. Changes in succinylation of mitochondrial proteins following variations in metabolism were compared against the mitochondrial redox state as estimated by the mitochondrial NAD+ /NADH ratio using fluorescent probes. The ratio was decreased by reduced glycolysis and/or glutathione depletion (iodoacetic acid; 2-deoxyglucose), depressed tricarboxylic acid cycle activity (carboxyethyl ester of succinyl phosphonate), and impairment of electron transport (antimycin) or ATP synthase (oligomycin), while uncouplers of oxidative phosphorylation (carbonyl cyanide m-chlorophenyl hydrazine or tyrphostin) increased the NAD+ /NADH ratio. All of the conditions decreased succinylation. In contrast, reducing the oxygen from 20% to 2.4% increased succinylation. The results demonstrate that succinylation varies with metabolic states, is not correlated to the mitochondrial NAD+ /NADH ratio, and may help coordinate the response to metabolic challenge.
- Published
- 2017
15. Methylene blue improves sensorimotor phenotype and decreases anxiety in parallel with activating brain mitochondria biogenesis in mid-age mice
- Author
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Vasily N. Popov, Mikhail Y. Syromyatnikov, Artem P. Gureev, Tatyana Gorbacheva, and Anatoly A. Starkov
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Male ,0301 basic medicine ,medicine.medical_specialty ,Bioenergetics ,NF-E2-Related Factor 2 ,SOD2 ,Anxiety ,Motor Activity ,Mitochondrion ,Biology ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,Animals ,NRF1 ,Maze Learning ,PI3K/AKT/mTOR pathway ,chemistry.chemical_classification ,Reactive oxygen species ,Organelle Biogenesis ,General Neuroscience ,Brain ,Hydrogen Peroxide ,General Medicine ,TFAM ,Antioxidant Response Elements ,Methylene Blue ,Mice, Inbred C57BL ,030104 developmental biology ,Endocrinology ,chemistry ,Signal transduction ,Energy Metabolism ,Reactive Oxygen Species ,Neuroscience ,030217 neurology & neurosurgery - Abstract
Age-related brain dysfunctions are associated with mitochondria malfunctions and increased risk of developing neurodegenerative diseases (ND). Recently, a mitochondria-targeting drug methylene blue has been drawing considerable interest as a potential treatment for ND. We found that aged mice manifested a decrease in physical endurance, spontaneous locomotor activity, and exploration concomitant with an increase in anxiety-related behavior, as compared to adult mice. Treating mice for 60 days with MB slowed down these changes. There were no significant changes in the animals' body weight, oxygen consumption rates, or respiratory quotient index, in adult or aged MB-treated mice. However, MB treatment significantly increased the generation of reactive oxygen species in brain mitochondria. The expression of several genes relevant to mitochondria biogenesis, bioenergetics, and antioxidant defense (NRF1, MTCOX1, TFAM, and SOD2) was greatly suppressed in aged mice; it was restored by MB treatment. It seems plausible that the effects of MB could be mediated by its ability to increase H2O2 production in brain mitochondria, thereby activating Nrf2/ARE signaling pathway and mitochondria biogenesis. Our data and earlier findings support the idea that MB can be an attractive prototype drug for developing safe and efficient gerontoprotective compounds.
- Published
- 2016
16. Method for detection of mtDNA damages for evaluating of pesticides toxicity for bumblebees (Bombus terrestris L.)
- Author
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O. V. Savinkova, Anatoly A. Starkov, Mikhail Y. Syromyatnikov, A. V. Lopatin, Vasily N. Popov, Natalia N. Starkova, and Artem P. Gureev
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0106 biological sciences ,0301 basic medicine ,Health, Toxicology and Mutagenesis ,medicine.disease_cause ,01 natural sciences ,DNA, Mitochondrial ,Toxicology ,03 medical and health sciences ,chemistry.chemical_compound ,Imidacloprid ,medicine ,Animals ,Pesticides ,Pollination ,Bumblebee ,biology ,General Medicine ,Hydrogen Peroxide ,Pesticide ,Bees ,biology.organism_classification ,Mitochondria ,010602 entomology ,030104 developmental biology ,Deltamethrin ,chemistry ,Bombus terrestris ,Malathion ,Esfenvalerate ,Agronomy and Crop Science ,Genotoxicity - Abstract
Bumblebees are important for crop pollination. Currently, the number of pollinators is decreasing worldwide, which is attributed mostly to the widespread use of pesticides. The aim of this work was to develop a method for assessing the genotoxicity of pesticides for the Bombus terrestris L. bumblebee using long-range PCR of mitochondrial DNA fragments. We have developed a panel of primers and assessed the genotoxicity of the following pesticides: imidacloprid, rotenone, deltamethrin, difenocanozole, malathion, metribuzin, penconazole, esfenvalerate, and dithianon. All pesticides (except imidacloprid) inhibited mitochondrial respiration fueled by pyruvate + malate; the strongest effect was observed for rotenone and difenocanozole. Three pesticides (dithianon, rotenone, and difenocanozole) affected the rate of H2O2 production. To study the pesticide-induced DNA damage in vitro and in vivo, we used three different mtDNA. The mtDNA damage was observed for all studied pesticides. Most of the studied pesticides caused significant damage to mtDNA in vitro and in vivo when ingested. Our results indicate that all tested pesticides, including herbicides and fungicides, can have a toxic effect on pollinators. However, the extent of pesticide-induced mtDNA damage in the flight muscles was significantly less upon the contact compared to the oral administration.
- Published
- 2019
17. Unique features of flight muscles mitochondria of honey bees (Apis mellifera L.)
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Mikhail Y. Syromyatnikov, Vasily N. Popov, Artem P. Gureev, Inna Yu. Vitkalova, and Anatoly A. Starkov
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0106 biological sciences ,0301 basic medicine ,Male ,Physiology ,media_common.quotation_subject ,Cell Respiration ,Insect ,Oxidative phosphorylation ,Mitochondrion ,01 natural sciences ,Biochemistry ,Membrane Potentials ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,Respiration ,Animals ,media_common ,biology ,Muscles ,fungi ,Temperature ,General Medicine ,Honey bee ,Hydrogen Peroxide ,Bees ,biology.organism_classification ,Mitochondria, Muscle ,010602 entomology ,Adenosine diphosphate ,030104 developmental biology ,chemistry ,Insect Science ,Bombus terrestris ,Flight, Animal ,behavior and behavior mechanisms ,Calcium ,Female ,Respiration rate - Abstract
Honey bees Apis mellifera L. are one of the most studied insect species due to their economic importance. The interest in studying honey bees chiefly stems from the recent rapid decrease in their world population, which has become a problem of food security. Nevertheless, there are no systemic studies on the properties of the mitochondria of honey bee flight muscles. We conducted a research of the mitochondria of the flight muscles of A. mellifera L. The influence of various organic substrates on mitochondrial respiration in the presence or absence of adenosine diphosphate (ADP) was investigated. We demonstrated that pyruvate is the optimal substrate for the coupled respiration. A combination of pyruvate and glutamate is required for the maximal respiration rate. We also show that succinate oxidation does not support the oxidative phosphorylation and the generation of membrane potential. We also studied the production of reactive oxygen species by isolated mitochondria. The greatest production of H2 O2 (as a percentage of the rate of oxygen consumed) in the absence of ADP was observed during the respiration supported by α-glycerophosphate, malate, and a combination of malate with another NAD-linked substrate. We showed that honey bee flight muscle mitochondria are unable to uptake Ca2+ -ions. We also show that bee mitochondria are able to oxidize the respiration substrates effectively at the temperature of 50°С compared to Bombus terrestris mitochondria, which were more adapted to lower temperatures.
- Published
- 2019
18. Redox-Dependent Loss of Flavin by Mitochondrial Complex I in Brain Ischemia/Reperfusion Injury
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Zoya V. Niatsetskaya, Csaba Konrad, Alexander Galkin, Anna Stepanova, Anatoly A. Starkov, Sergey A. Sosunov, Giovanni Manfredi, Ilka Wittig, and Vadim S. Ten
- Subjects
0301 basic medicine ,animal structures ,Physiology ,Flavin Mononucleotide ,Clinical Biochemistry ,Flavin mononucleotide ,Flavin group ,Biochemistry ,Redox ,Brain ischemia ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,Structure-Activity Relationship ,Flavins ,medicine ,Animals ,Molecular Biology ,General Environmental Science ,Forum Original Research Communications ,Electron Transport Complex I ,030102 biochemistry & molecular biology ,Cell Biology ,Hydrogen Peroxide ,medicine.disease ,Cell biology ,Mitochondria ,Oxygen ,Oxidative Stress ,030104 developmental biology ,chemistry ,Animals, Newborn ,Reperfusion Injury ,Hypoxia-Ischemia, Brain ,General Earth and Planetary Sciences ,Reactive Oxygen Species ,Reperfusion injury ,Oxidation-Reduction ,Function (biology) ,Mitochondrial Complex I - Abstract
Aims: Brain ischemia/reperfusion (I/R) is associated with impairment of mitochondrial function. However, the mechanisms of mitochondrial failure are not fully understood. This work was undertaken to determine the mechanisms and time course of mitochondrial energy dysfunction after reperfusion following neonatal brain hypoxia-ischemia (HI) in mice. Results: HI/reperfusion decreased the activity of mitochondrial complex I, which was recovered after 30 min of reperfusion and then declined again after 1 h. Decreased complex I activity occurred in parallel with a loss in the content of noncovalently bound membrane flavin mononucleotide (FMN). FMN dissociation from the enzyme is caused by succinate-supported reverse electron transfer. Administration of FMN precursor riboflavin before HI/reperfusion was associated with decreased infarct volume, attenuation of neurological deficit, and preserved complex I activity compared with vehicle-treated mice. In vitro, the rate of FMN release during oxidation of succinate was not affected by the oxygen level and amount of endogenously produced reactive oxygen species. Innovation: Our data suggest that dissociation of FMN from mitochondrial complex I may represent a novel mechanism of enzyme inhibition defining respiratory chain failure in I/R. Strategies preventing FMN release during HI and reperfusion may limit the extent of energy failure and cerebral HI injury. The proposed mechanism of acute I/R-induced complex I impairment is distinct from the generally accepted mechanism of oxidative stress-mediated I/R injury. Conclusion: Our study is the first to highlight a critical role of mitochondrial complex I-FMN dissociation in the development of HI-reperfusion injury of the neonatal brain. Antioxid. Redox Signal. 31, 608–622.
- Published
- 2019
19. Autophagy Induction by Bexarotene Promotes Mitophagy in Presenilin 1 Familial Alzheimer's Disease iPSC-Derived Neural Stem Cells
- Author
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Patricia Martín-Maestro, Scott Noggle, Meri Gerges, Dominik Paquet, Andrew Sproul, Anatoly A. Starkov, and Hector Martinez
- Subjects
0301 basic medicine ,Induced Pluripotent Stem Cells ,Neuroscience (miscellaneous) ,Mitochondrion ,Biology ,DNA, Mitochondrial ,Presenilin ,Article ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,Neural Stem Cells ,Alzheimer Disease ,Mitophagy ,Autophagy ,Presenilin-1 ,Cytochrome c oxidase ,Humans ,Neurogenesis ,Neural stem cell ,Cell biology ,Mitochondria ,030104 developmental biology ,Neurology ,Bexarotene ,Coenzyme Q – cytochrome c reductase ,biology.protein ,030217 neurology & neurosurgery - Abstract
Adult neurogenesis defects have been demonstrated in the brains of Alzheimer's disease (AD) patients. The neurogenesis impairment is an early critical event in the course of familiar AD (FAD) associated with neuronal loss. It was suggested that neurologic dysfunction in AD may be caused by impaired functioning of hippocampal neural stem cells (NSCs). Multiple metabolic and structural abnormalities in neural mitochondria have long been suspected to play a critical role in AD pathophysiology. We hypothesize that the cause of such abnormalities could be defective elimination of damaged mitochondria. In the present study, we evaluated mitophagy efficacy in a cellular AD model, hiPSC-derived NSCs harboring the FAD-associated PS1 M146L mutation. We found several mitochondrial respiratory chain defects such as lower expression levels of cytochrome c oxidase (complex IV), cytochrome c reductase (complex III), succinate dehydrogenase (complex II), NADH:CoQ reductase (complex I), and also ATP synthase (complex V), most of which had been previously associated with AD. The mitochondrial network morphology and abundance in these cells was aberrant. This was associated with a marked mitophagy failure stemming from autophagy induction blockage, and deregulation of the expression of proteins involved in mitochondrial dynamics. We show that treating these cells with autophagy-stimulating drug bexarotene restored autophagy and compensated mitochondrial anomalies in PS1 M146L NSCs, by enhancing the clearance of mitochondria. Our data support the hypothesis that pharmacologically induced mitophagy enhancement is a relevant and novel therapeutic strategy for the treatment of AD.
- Published
- 2019
20. Mitochondrial Dysfunction and Permeability Transition in Neonatal Brain and Lung Injuries
- Author
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Veniamin Ratner, Anna A. Stepanova, Vadim S. Ten, Sergey A. Sosunov, Maria Neginskaya, Zoya V. Niatsetskaya, and Anatoly A. Starkov
- Subjects
0301 basic medicine ,Basic science ,brain ,Encephalopathy ,Review ,Mitochondrion ,Bioinformatics ,Permeability ,Pathogenesis ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,medicine ,Humans ,lcsh:QH301-705.5 ,lungs ,Lung ,business.industry ,MPTP ,prematurity ,Infant, Newborn ,Lung Injury ,General Medicine ,medicine.disease ,mitochondria ,030104 developmental biology ,medicine.anatomical_structure ,lcsh:Biology (General) ,Mitochondrial permeability transition pore ,chemistry ,Bronchopulmonary dysplasia ,Brain Injuries ,business ,030217 neurology & neurosurgery ,proton leak - Abstract
This review discusses the potential mechanistic role of abnormally elevated mitochondrial proton leak and mitochondrial bioenergetic dysfunction in the pathogenesis of neonatal brain and lung injuries associated with premature birth. Providing supporting evidence, we hypothesized that mitochondrial dysfunction contributes to postnatal alveolar developmental arrest in bronchopulmonary dysplasia (BPD) and cerebral myelination failure in diffuse white matter injury (WMI). This review also analyzes data on mitochondrial dysfunction triggered by activation of mitochondrial permeability transition pore(s) (mPTP) during the evolution of perinatal hypoxic-ischemic encephalopathy. While the still cryptic molecular identity of mPTP continues to be a subject for extensive basic science research efforts, the translational significance of mitochondrial proton leak received less scientific attention, especially in diseases of the developing organs. This review is focused on the potential mechanistic relevance of mPTP and mitochondrial dysfunction to neonatal diseases driven by developmental failure of organ maturation or by acute ischemia-reperfusion insult during development.
- Published
- 2021
21. Discovery of LRE1 as a specific and allosteric inhibitor of soluble adenylyl cyclase
- Author
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Antonio Alvau, Clemens Steegborn, Joop van den Heuvel, Giovanni Manfredi, Federica Valsecchi, Hannes Buck, Jonathan H. Zippin, Anatoly A. Starkov, J. Fraser Glickman, Lonny R. Levin, Felipe Navarrete, Carolina Adura, Jochen Buck, Silke Kleinboelting, Lavoisier Ramos-Espiritu, Pablo E. Visconti, and Helmholtz-Zentrum für Infektionsforschung GmbH, Inhoffenstr. 7, 38124 Braunschweig, Germany.
- Subjects
Models, Molecular ,0301 basic medicine ,Allosteric regulation ,Thiophenes ,Cyclase ,Article ,ADCY10 ,Adenylyl cyclase ,Structure-Activity Relationship ,03 medical and health sciences ,chemistry.chemical_compound ,Allosteric Regulation ,Humans ,education ,Molecular Biology ,education.field_of_study ,Dose-Response Relationship, Drug ,Molecular Structure ,Activator (genetics) ,Chemistry ,ADCY9 ,Cell Biology ,Soluble adenylyl cyclase ,Pyrimidines ,030104 developmental biology ,Solubility ,Biochemistry ,Adenylyl Cyclase Inhibitors ,Second messenger system ,Adenylyl Cyclases - Abstract
The prototypical second messenger cAMP regulates a wide variety of physiological processes. It can simultaneously mediate diverse functions by acting locally in independently regulated microdomains. In mammalian cells, two types of adenylyl cyclase generate cAMP: G-protein-regulated transmembrane adenylyl cyclases and bicarbonate-, calcium- and ATP-regulated soluble adenylyl cyclase (sAC). Because each type of cyclase regulates distinct microdomains, methods to distinguish between them are needed to understand cAMP signaling. We developed a mass-spectrometry-based adenylyl cyclase assay, which we used to identify a new sAC-specific inhibitor, LRE1. LRE1 bound to the bicarbonate activator binding site and inhibited sAC via a unique allosteric mechanism. LRE1 prevented sAC-dependent processes in cellular and physiological systems, and it will facilitate exploration of the therapeutic potential of sAC inhibition.
- Published
- 2016
22. Divalent cation chelators citrate and EDTA unmask an intrinsic uncoupling pathway in isolated mitochondria
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Vasily N. Popov, Natalia N. Starkova, Anatoly A. Starkov, Csaba Konrad, Christos Chinopoulos, Anna Stepanova, and Gergely Kiss
- Subjects
0301 basic medicine ,Cations, Divalent ,Physiology ,ATPase ,Magnesium Chloride ,Mitochondrion ,Article ,Citric Acid ,Ion Channels ,Divalent ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,Animals ,Humans ,Citrate synthase ,Inner mitochondrial membrane ,Melanoma ,Edetic Acid ,Membrane potential ,chemistry.chemical_classification ,biology ,Brain ,Biological Transport ,Hydrogen Peroxide ,Cell Biology ,Mitochondria ,Rats ,030104 developmental biology ,chemistry ,Biochemistry ,Mitochondrial Membranes ,biology.protein ,ATP–ADP translocase ,Reactive Oxygen Species ,Citric acid - Abstract
We demonstrate a suppression of ROS production and uncoupling of mitochondria by exogenous citrate in Mg2+ free medium. Exogenous citrate suppressed H2O2 emission and depolarized mitochondria. The depolarization was paralleled by the stimulation of respiration of mitochondria. The uncoupling action of citrate was independent of the presence of sodium, potassium, or chlorine ions, and it was not mediated by the changes in permeability of the inner mitochondrial membrane to solutes. The citrate transporter was not involved in the citrate effect. Inhibitory analysis data indicated that several well described mitochondria carriers and channels (ATPase, IMAC, ADP/ATP translocase, mPTP, mKATP) were not involved in citrate’s effect. Exogenous MgCl2 strongly inhibited citrate-induced depolarization. The uncoupling effect of citrate was demonstrated in rat brain, mouse brain, mouse liver, and human melanoma cells mitochondria. We interpreted the data as an evidence to the existence of a hitherto undescribed putative inner mitochondrial membrane channel that is regulated by extramitochondrial Mg2+ or other divalent cations.
- Published
- 2016
23. The effect of fenofibrate on expression of genes involved in fatty acids beta-oxidation and associated free-radical processes
- Author
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Vasily N. Popov, Artem P. Gureev, M L Shmatkova, Anatoly A. Starkov, and V Yu Bashmakov
- Subjects
Male ,0301 basic medicine ,medicine.medical_specialty ,Peroxiredoxin III ,SOD2 ,TRPV Cation Channels ,Mitochondria, Liver ,Oxidative phosphorylation ,General Biochemistry, Genetics and Molecular Biology ,Lipid peroxidation ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,Superoxide Dismutase-1 ,0302 clinical medicine ,Fenofibrate ,Internal medicine ,Peroxisomes ,medicine ,Animals ,Beta oxidation ,Hypolipidemic Agents ,chemistry.chemical_classification ,Reactive oxygen species ,Superoxide Dismutase ,Fatty Acids ,Hypertriglyceridemia ,Peroxiredoxins ,General Medicine ,Peroxisome ,medicine.disease ,Mice, Inbred C57BL ,030104 developmental biology ,Endocrinology ,Liver ,chemistry ,Biochemistry ,030220 oncology & carcinogenesis ,Calcium Channels ,Reactive Oxygen Species ,medicine.drug - Abstract
Fenofibrate is a synthetic ligand for peroxisome proliferator-activated receptors subtype alpha (PPARa); it is used for the treatment of a wide range of metabolic diseases such as hypertriglyceridemia, dyslipidemia, diabetes and various neurodegenerative diseases. We have studied the effect of fenofibrate on b-oxidation of fatty acids and related free-radical processes. The most effective concentration of fenofibrate (0.3%) added to the chow caused a significant decrease of the body weight of mice. The data obtained by quantitative PCR demonstrated increased hepatic gene expression responsible for b-oxidation of fatty acids in peroxisomes and mitochondria. Enhancement of oxidative processes caused a 2-fold increase in the rate of reactive oxygen species (ROS) production, as evidenced by determination of the level of lipid peroxidation (LPO) products in the liver. Mitochondrial antioxidant systems are more sensitive to elevated ROS production, as they respond by increased expression of SOD2 and PRDX3 genes, than cytoplasmic and peroxisomal antioxidant systems, where expression of CAT1, SOD1, PRDX5 genes remained unaltered.Fenofibrat – sinteticheskiĭ ligand aktiviruiushchikh proliferatsiiu peroksisom retseptorov podtipa al'fa (PPARa), kotoryĭ ispol'zuetsia dlia lecheniia shirokogo spektra metabolicheskikh zabolevaniĭ, takikh kak gipertriglitseridemii, dislipidemii, diabety, razlichnogo roda neĭrodegenerativnye zabolevaniia. Nami issledovano vliianie fenofibrata na b-okislenie zhirnykh kislot i sviazannye s nim svobodnoradikal'nye protsessy. Naibolee éffektivnaia kontsentratsiia fenofibrata (0,3%), dobavlennaia v korm, privodila k znachitel'nomu snizheniiu massy tela u mysheĭ. Dannye, poluchennye metodom kolichestvennogo PTsR, svidetel'stvuiut ob uvelichenii ékspressii genov pecheni, kodiruiushchikh fermenty b-okisleniia zhirnykh kislot, protekaiushchego kak v peroksisomakh, tak i v mitokhondriiakh. Usilenie okislitel'nykh protsessov vdvoe uvelichivaet skorost' produktsii aktivnykh form kisloroda (AFK), chto podtverzhdaetsia opredeleniem urovnia soderzhaniia produktov perekisnogo okisleniia lipidov (POL) v pecheni. Pri étom mitokhondrial'nye antioksidantnye sistemy bolee chuvstvitel'ny k povysheniiu produktsii AFK, chem peroksisomnye i tsitoplazmaticheskie antioksidantnye sistemy. Ob étom svidetel'stvuiut uvelichenie ékspressii genov SOD2 i PRDX3 i otsutstvie izmeneniĭ v ékspressii genov CAT1, SOD1, PRDX5.
- Published
- 2016
24. Crosstalk between the mTOR and Nrf2/ARE signaling pathways as a target in the improvement of long-term potentiation
- Author
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Anatoly A. Starkov, Artem P. Gureev, and Vasily N. Popov
- Subjects
0301 basic medicine ,Memory, Long-Term ,NF-E2-Related Factor 2 ,Long-Term Potentiation ,Mitochondrion ,Article ,03 medical and health sciences ,0302 clinical medicine ,Developmental Neuroscience ,Animals ,Humans ,PI3K/AKT/mTOR pathway ,Long-term memory ,Chemistry ,TOR Serine-Threonine Kinases ,Autophagy ,Long-term potentiation ,Receptor Cross-Talk ,Antioxidant Response Elements ,Crosstalk (biology) ,030104 developmental biology ,Neurology ,Synaptic plasticity ,Signal transduction ,Neuroscience ,030217 neurology & neurosurgery ,Signal Transduction - Abstract
In recent years, a significant progress was made in understanding molecular mechanisms of long-term memory. Long-term memory formation requires strengthening of neuronal connections (LTP, long-term potentiation) associated with structural rearrangement of neurons. The key role in the synthesis of proteins essential for these rearrangements belong to mTOR (mammalian target of rapamycin) complexes and signaling pathways involved in mTOR regulation. Suppression of mTOR activity may impair synaptic plasticity and long-term memory, while mTOR activation inhibits autophagy, thereby potentiating amyloidosis and development of Alzheimer's disease (AD) accompanied by irreversible memory loss. Because of this, suppression/inhibition of mTOR might have unpredictable consequences on memory. The Nrf2/ARE signaling pathway affects almost all mitochondrial processes. The activation of this pathway improves memory and exhibits therapeutic effect in AD. In this review, we discuss the crosstalk between the Nrf2/ARE signaling and mTOR in the maintenance of synaptic plasticity. Nrf2 pathway can be activated by pharmacological agents and by changes in mitochondria functioning accompanying various neuronal dysfunctions.
- Published
- 2020
25. Estrogen Receptor Beta Modulates Permeability Transition in Brain Mitochondria
- Author
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Anatoly A. Starkov, Suzanne R. Burstein, Jasmine A. Fels, Ping Zhou, Liping Qian, Costantino Iadecola, Hyun Jeong Kim, Giovanni Manfredi, and Sheng Zhang
- Subjects
0301 basic medicine ,Male ,Estrogen receptor ,Mitochondrion ,Biochemistry ,Hippocampus ,Mitochondrial Membrane Transport Proteins ,Tissue Culture Techniques ,Cyclophilins ,Mice ,0302 clinical medicine ,Piperidines ,Chlorocebus aethiops ,Adenosine Triphosphatases ,Membrane Potential, Mitochondrial ,Mice, Knockout ,biology ,Chemistry ,Neurodegeneration ,Glutamate receptor ,Mitochondrial Proton-Translocating ATPases ,Cell biology ,Mitochondria ,COS Cells ,Cyclosporine ,Female ,Cyclophilin D ,Protein Binding ,Biophysics ,Article ,03 medical and health sciences ,Mitochondrial membrane transport protein ,Prosencephalon ,Sex Factors ,medicine ,Animals ,Estrogen Receptor beta ,Estrogen receptor beta ,Mitochondrial Permeability Transition Pore ,Membrane Proteins ,Cell Biology ,Microtomy ,medicine.disease ,Mice, Inbred C57BL ,030104 developmental biology ,Mitochondrial permeability transition pore ,Forebrain ,biology.protein ,Pyrazoles ,Calcium ,Carrier Proteins ,030217 neurology & neurosurgery - Abstract
Recent evidence highlights a role for sex and hormonal status in regulating cellular responses to ischemic brain injury and neurodegeneration. A key pathological event in ischemic brain injury is the opening of a mitochondrial permeability transition pore (MPT) induced by excitotoxic calcium levels, which can trigger irreversible damage to mitochondria accompanied by the release of pro-apoptotic factors. However, sex differences in brain MPT modulation have not yet been explored. Here, we show that mitochondria isolated from female mouse forebrain have a lower calcium threshold for MPT than male mitochondria, and that this sex difference depends on the MPT regulator cyclophilin D (CypD). We also demonstrate that an estrogen receptor beta (ERβ) antagonist inhibits MPT and knockout of ERβ decreases the sensitivity of mitochondria to the CypD inhibitor, cyclosporine A. These results suggest a functional relationship between ERβ and CypD in modulating brain MPT. Moreover, co-immunoprecipitation studies identify several ERβ binding partners in mitochondria. Among these, we investigate the mitochondrial ATPase as a putative site of MPT regulation by ERβ. We find that previously described interaction between the oligomycin sensitivity-conferring subunit of ATPase (OSCP) and CypD is decreased by ERβ knockout, suggesting that ERβ modulates MPT by regulating CypD interaction with OSCP. Functionally, in primary neurons and hippocampal slice cultures, modulation of ERβ has protective effects against glutamate toxicity and oxygen glucose deprivation, respectively. Taken together, these results reveal a novel pathway of brain MPT regulation by ERβ that could contribute to sex differences in ischemic brain injury and neurodegeneration.
- Published
- 2018
26. Antihelminthic Benzimidazoles Are Novel HIF Activators That Prevent Oxidative Neuronal DeathviaBinding to Tubulin
- Author
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Irina G. Gazaryan, Anatoly A. Starkov, Sama F. Sleiman, Brett Langley, Julie K. Andersen, Camille Brochier, Ambreena Siddiq, Manuela Basso, Gregory J. Riggins, Thong C. Ma, Hossein Aleyasin, Susan Bane, Saravanan S. Karuppagounder, Rajiv R. Ratan, Shankar J. Chinta, Renée E. Haskew-Layton, and Amit Kumar
- Subjects
Cyclin-Dependent Kinase Inhibitor p21 ,Cell Survival ,Physiology ,Blotting, Western ,Clinical Biochemistry ,Pharmacology ,Hippocampus ,Biochemistry ,Cell Line ,Mice ,Neuroblast ,Tubulin ,Transcription (biology) ,medicine ,Animals ,Humans ,Luciferase ,Molecular Biology ,General Environmental Science ,Anthelmintics ,Neurons ,biology ,Activator (genetics) ,Cell Biology ,Hypoxia (medical) ,Hypoxia-Inducible Factor 1, alpha Subunit ,Immunohistochemistry ,Molecular biology ,Forum Original Research CommunicationsStroke (S. Cho and R. R. Ratan, Eds.) ,Mebendazole ,Cell culture ,biology.protein ,General Earth and Planetary Sciences ,Benzimidazoles ,Pharmacophore ,medicine.symptom - Abstract
Aims: Pharmacological activation of the adaptive response to hypoxia is a therapeutic strategy of growing interest for neurological conditions, including stroke, Huntington's disease, and Parkinson's disease. We screened a drug library with known safety in humans using a hippocampal neuroblast line expressing a reporter of hypoxia-inducible factor (HIF)-dependent transcription. Results: Our screen identified more than 40 compounds with the ability to induce hypoxia response element-driven luciferase activity as well or better than deferoxamine, a canonical activator of hypoxic adaptation. Among the chemical entities identified, the antihelminthic benzimidazoles represented one pharmacophore that appeared multiple times in our screen. Secondary assays confirmed that antihelminthics stabilized the transcriptional activator HIF-1α and induced expression of a known HIF target gene, p21cip1/waf1, in post-mitotic cortical neurons. The on-target effect of these agents in stimulating hypoxic signaling was binding to free tubulin. Moreover, antihelminthic benzimidazoles also abrogated oxidative stress-induced death in vitro, and this on-target effect also involves binding to free tubulin. Innovation and Conclusions: These studies demonstrate that tubulin-binding drugs can activate a component of the hypoxic adaptive response, specifically the stabilization of HIF-1α and its downstream targets. Tubulin-binding drugs, including antihelminthic benzimidazoles, also abrogate oxidative neuronal death in primary neurons. Given their safety in humans and known ability to penetrate into the central nervous system, antihelminthic benzimidazoles may be considered viable candidates for treating diseases associated with oxidative neuronal death, including stroke. Antioxid. Redox Signal. 22, 121–134.
- Published
- 2015
27. Reverse electron transfer results in a loss of flavin from mitochondrial complex I: Potential mechanism for brain ischemia reperfusion injury
- Author
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Vadim S. Ten, Anna Stepanova, Csaba Konrad, Anja Kahl, Anatoly S. Starkov, and Alexander Galkin
- Subjects
0301 basic medicine ,Male ,medicine.medical_specialty ,Ischemia ,ischemia ,Flavin group ,Mitochondrion ,Brain Ischemia ,Brain ischemia ,Electron Transport ,03 medical and health sciences ,Electron transfer ,0302 clinical medicine ,Internal medicine ,Flavins ,medicine ,Animals ,Stroke ,Potential mechanism ,Electron Transport Complex I ,business.industry ,Brain ,flavin ,succinate ,medicine.disease ,stroke ,Mitochondria ,mitochondria ,Mice, Inbred C57BL ,Oxidative Stress ,030104 developmental biology ,Neurology ,Biochemistry ,Rapid Communications ,Reperfusion Injury ,Cardiology ,Neurology (clinical) ,Cardiology and Cardiovascular Medicine ,business ,Reactive Oxygen Species ,Reperfusion injury ,030217 neurology & neurosurgery - Abstract
Ischemic stroke is one of the most prevalent sources of disability in the world. The major brain tissue damage takes place upon the reperfusion of ischemic tissue. Energy failure due to alterations in mitochondrial metabolism and elevated production of reactive oxygen species (ROS) is one of the main causes of brain ischemia-reperfusion (IR) damage. Ischemia resulted in the accumulation of succinate in tissues, which favors the process of reverse electron transfer (RET) when a fraction of electrons derived from succinate is directed to mitochondrial complex I for the reduction of matrix NAD+.We demonstrate that in intact brain mitochondria oxidizing succinate, complex I became damaged and was not able to contribute to the physiological respiration. This process is associated with a decline in ROS release and a dissociation of the enzyme's flavin. This previously undescribed phenomenon represents the major molecular mechanism of injury in stroke and induction of oxidative stress after reperfusion. We also demonstrate that the origin of ROS during RET is flavin of mitochondrial complex I. Our study highlights a novel target for neuroprotection against IR brain injury and provides a sensitive biochemical marker for this process.
- Published
- 2017
28. Mutant TDP-43 does not impair mitochondrial bioenergetics in vitro and in vivo
- Author
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Giovanni Manfredi, Federica Valsecchi, Meri Gerges, Csaba Konrad, Gloria M. Palomo, Pablo M. Peixoto, Kirsten Bredvik, John Ravits, Leonard Petrucelli, Anatoly A. Starkov, and Hibiki Kawamata
- Subjects
0301 basic medicine ,TAR DNA-binding protein 43 ,TDP-43 ,SOD1 ,Mutant ,Respiratory chain ,Mice, Transgenic ,Oxidative phosphorylation ,Bioenergetics ,lcsh:Geriatrics ,Mitochondrion ,Oxidative Phosphorylation ,lcsh:RC346-429 ,Cell Line ,Mice ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,Mutant protein ,mental disorders ,Animals ,Humans ,Mitochondrial calcium uptake ,Molecular Biology ,lcsh:Neurology. Diseases of the nervous system ,ATP synthase ,biology ,Brain ,nutritional and metabolic diseases ,Molecular biology ,Mitochondria ,nervous system diseases ,DNA-Binding Proteins ,lcsh:RC952-954.6 ,030104 developmental biology ,Mutation ,biology.protein ,Calcium ,Neurology (clinical) ,ALS ,Energy Metabolism ,030217 neurology & neurosurgery ,Research Article - Abstract
Background Mitochondrial dysfunction has been linked to the pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Functional studies of mitochondrial bioenergetics have focused mostly on superoxide dismutase 1 (SOD1) mutants, and showed that mutant human SOD1 impairs mitochondrial oxidative phosphorylation, calcium homeostasis, and dynamics. However, recent reports have indicated that alterations in transactivation response element DNA-binding protein 43 (TDP-43) can also lead to defects of mitochondrial morphology and dynamics. Furthermore, it was proposed that TDP-43 mutations cause oxidative phosphorylation impairment associated with respiratory chain defects and that these effects were caused by mitochondrial localization of the mutant protein. Here, we investigated the presence of bioenergetic defects in the brain of transgenic mice expressing human mutant TDP-43 (TDP-43A315T mice), patient derived fibroblasts, and human cells expressing mutant forms of TDP-43. Methods In the brain of TDP-43A315T mice, TDP-43 mutant fibroblasts, and cells expressing mutant TDP-43, we tested several bioenergetics parameters, including mitochondrial respiration, ATP synthesis, and calcium handling. Differences between mutant and control samples were evaluated by student t-test or by ANOVA, followed by Bonferroni correction, when more than two groups were compared. Mitochondrial localization of TDP-43 was investigated by immunocytochemistry in fibroblasts and by subcellular fractionation and western blot of mitochondrial fractions in mouse brain. Results We did not observe defects in any of the mitochondrial bioenergetic functions that were tested in TDP-43 mutants. We detected a small amount of TDP-43A315T peripherally associated with brain mitochondria. However, there was no correlation between TDP-43 associated with mitochondria and respiratory chain dysfunction. In addition, we observed increased calcium uptake in mitochondria from TDP-43A315T mouse brain and cells expressing A315T mutant TDP-43. Conclusions While alterations of mitochondrial morphology and dynamics in TDP-43 mutant neurons are well established, the present study did not demonstrate oxidative phosphorylation defects in TDP-43 mutants, in vitro and in vivo. On the other hand, the increase in mitochondrial calcium uptake in A315T TDP-43 mutants was an intriguing finding, which needs to be investigated further to understand its mechanisms and potential pathogenic implications.
- Published
- 2017
29. Simplified qPCR method for detecting excessive mtDNA damage induced by exogenous factors
- Author
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Vasily N. Popov, Anatoly A. Starkov, Ekaterina A. Shaforostova, and Artem P. Gureev
- Subjects
0301 basic medicine ,Male ,Mitochondrial DNA ,DNA damage ,DNA polymerase ,Mitochondrion ,Toxicology ,medicine.disease_cause ,DNA, Mitochondrial ,Polymerase Chain Reaction ,Article ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,law ,Rotenone ,medicine ,Animals ,Polymerase chain reaction ,Genetics ,biology ,Brain ,Hydrogen Peroxide ,Molecular biology ,Nuclear DNA ,Mitochondria ,Mice, Inbred C57BL ,030104 developmental biology ,Liver ,biology.protein ,Primer (molecular biology) ,030217 neurology & neurosurgery ,Genotoxicity ,DNA Damage - Abstract
Damage to mitochondrial DNA (mtDNA) is a meaningful biomarker for evaluating genotoxicity of drugs and environmental toxins. Existing PCR methods utilize long mtDNA fragments (~8–10 kb), which complicates detecting exact sites of mtDNA damage. To identify the mtDNA regions most susceptible to damage, we have developed and validated a set of primers to amplify ~2 kb long fragments, while covering over 95% of mouse mtDNA. We have modified the detection method by greatly increasing the enrichment of mtDNA, which allows us solving the problem of non-specific primer annealing to nuclear DNA. To validate our approach, we have determined the most damage-susceptible mtDNA regions in mice treated in vivo and in vitro with rotenone and H2O2. The GTGR-sequence-enriched mtDNA segments located in the D-loop region were found to be especially susceptible to damage. Further, we demonstrate that H2O2-induced mtDNA damage facilitates the relaxation of mtDNA supercoiled conformation, making the sequences with minimal damage more accessible to DNA polymerase, which, in turn, results in a decrease in threshold cycle value. Overall, our modified PCR method is simpler and more selective to the specific sites of damage in mtDNA.
- Published
- 2017
30. Distinct intracellular sAC-cAMP domains regulate ER calcium signaling and OXPHOS function
- Author
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Anna Stepanova, Anatoly S. Starkov, Jordi Magrané, Suzanne R. Burstein, Alexander Galkin, Csaba Konrad, Lavoisier Ramos-Espiritu, Marilena D'Aurelio, Giovanni Manfredi, Federica Valsecchi, Lonny R. Levin, and Jochen Buck
- Subjects
0301 basic medicine ,education.field_of_study ,Endoplasmic reticulum ,Cell Biology ,Mitochondrion ,Biology ,Soluble adenylyl cyclase ,Cell biology ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Mitochondrial biogenesis ,Second messenger system ,Journal Article ,Phosphorylation ,education ,030217 neurology & neurosurgery ,Intracellular ,Calcium signaling - Abstract
cAMP regulates a wide variety of physiological functions in mammals. This single second messenger can regulate multiple, seemingly disparate functions within independently regulated cell compartments. We have previously identified one such compartment inside the matrix of the mitochondria, where soluble adenylyl cyclase (sAC) regulates oxidative phosphorylation (OXPHOS). We now show that sAC knockout fibroblasts have a defect in OXPHOS activity and attempt to compensate for this defect by increasing OXPHOS proteins. Importantly, sAC knockout cells also exhibit decreased probability of endoplasmic reticulum (ER) Ca2+ release associated with diminished phosphorylation of the inositol 3-phosphate receptor. Restoring sAC expression exclusively in the mitochondrial matrix rescues OXPHOS activity and reduces mitochondrial biogenesis, indicating that these phenotypes are regulated by intramitochondrial sAC. In contrast, Ca2+ release from the ER is only rescued when sAC expression is restored throughout the cell. Thus, we show that functionally distinct, sAC-defined, intracellular cAMP signaling domains regulate metabolism and Ca2+ signaling.
- Published
- 2017
31. Perfluoroalkyl acids-induced liver steatosis: Effects on genes controlling lipid homeostasis
- Author
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Carmen R. Wood, J. Christopher Corton, Barbara D. Abbott, Anatoly A. Starkov, Mimi T. Lin, Kaberi P. Das, Kendall B. Wallace, and Christopher Lau
- Subjects
0301 basic medicine ,Male ,medicine.medical_specialty ,Palmitates ,Mitochondria, Liver ,010501 environmental sciences ,Toxicology ,01 natural sciences ,Article ,Perfluorononanoic acid ,Rats, Sprague-Dawley ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,Internal medicine ,Cell Line, Tumor ,medicine ,Oil Red O ,Animals ,Homeostasis ,Humans ,PPAR alpha ,Carnitine ,Triglycerides ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Mice, Knockout ,Fluorocarbons ,Gene Expression Profiling ,Fatty Acids ,Fatty acid ,Lipid metabolism ,DNA ,Peroxisome ,medicine.disease ,Lipid Metabolism ,Fatty Liver ,030104 developmental biology ,Endocrinology ,chemistry ,Alkanesulfonic Acids ,Gene Expression Regulation ,Liver ,Perfluorooctanoic acid ,Environmental Pollutants ,Steatosis ,medicine.drug - Abstract
Persistent presence of perfluoroalkyl acids (PFAAs) in the environment is due to their extensive use in industrial and consumer products, and their slow decay. Biochemical tests in rodent demonstrated that these chemicals are potent modifiers of lipid metabolism and cause hepatocellular steatosis. However, the molecular mechanism of PFAAs interference with lipid metabolism remains to be elucidated. Currently, two major hypotheses are that PFAAs interfere with mitochondrial beta-oxidation of fatty acids and/or they affect the transcriptional activity of peroxisome proliferator-activated receptor α (PPARα) in liver. To determine the ability of structurally-diverse PFAAs to cause steatosis, as well as to understand the underlying molecular mechanisms, wild-type (WT) and PPARα-null mice were treated with perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), or perfluorohexane sulfonate (PFHxS), by oral gavage for 7 days, and their effects were compared to that of PPARα agonist WY-14643 (WY), which does not cause steatosis. Increases in liver weight and cell size, and decreases in DNA content per mg of liver, were observed for all compounds in WT mice, and were also seen in PPARα-null mice for PFOA, PFNA, and PFHxS, but not for WY. In Oil Red O stained sections, WT liver showed increased lipid accumulation in all treatment groups, whereas in PPARα-null livers, accumulation was observed after PFNA and PFHxS treatment, adding to the burden of steatosis observed in control (untreated) PPARα-null mice. Liver triglyceride (TG) levels were elevated in WT mice by all PFAAs and in PPARα-null mice only by PFNA. In vitro β-oxidation of palmitoyl carnitine by isolated rat liver mitochondria was not inhibited by any of the 7 PFAAs tested. Likewise, neither PFOA nor PFOS inhibited palmitate oxidation by HepG2/C3A human liver cell cultures. Microarray analysis of livers from PFAAs-treated mice indicated that the PFAAs induce the expression of the lipid catabolism genes, as well as those involved in fatty acid and triglyceride synthesis, in WT mice and, to a lesser extent, in PPARα-null mice. These results indicate that most of the PFAAs increase liver TG load and promote steatosis in mice We hypothesize that PFAAs increase steatosis because the balance of fatty acid accumulation/synthesis and oxidation is disrupted to favor accumulation.
- Published
- 2016
32. An update on the role of mitochondrial α-ketoglutarate dehydrogenase in oxidative stress
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Anatoly A. Starkov
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chemistry.chemical_classification ,Reactive oxygen species ,Reactive oxygen species metabolism ,Neurodegeneration ,Ketoglutarate dehydrogenase ,Cell Biology ,Disease ,Mitochondrion ,Biology ,medicine.disease ,medicine.disease_cause ,Article ,Mitochondria ,Oxidative Stress ,Cellular and Molecular Neuroscience ,chemistry ,Biochemistry ,medicine ,Animals ,Humans ,Ketoglutarate Dehydrogenase Complex ,Dehydrogenase complex ,Reactive Oxygen Species ,Molecular Biology ,Oxidative stress - Abstract
The activity of mitochondrial alpha-ketoglutarate dehydrogenase complex (KGDHC) is severely reduced in human pathologies where oxidative stress is traditionally thought to play an important role, such as familial and sporadic forms of Alzheimer's disease and other age-related neurodegenerative diseases. This minireview is focused on substantial data that were accumulated over the last 2 decades to support the concept that KGDHC can be a primary mitochondrial target of oxidative stress and at the same time a key contributor to it by producing reactive oxygen species. This article is part of a Special Issue entitled 'Mitochondrial function and dysfunction in neurodegeneration'.
- Published
- 2013
33. Pioglitazone halts axonal degeneration in a mouse model of X-linked adrenoleukodystrophy
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Montserrat Ruiz, Patrick Aubourg, Laia Morató, Reinald Pamplona, Manuel Portero-Otin, Aurora Pujol, Jorge Galino, Magali Dumont, Noel Y. Calingasan, Elena Galea, Anatoly A. Starkov, Juan José Martínez, Stéphane Fourcade, Alba Naudí, M. Flint Beal, and Isidre Ferrer
- Subjects
medicine.medical_specialty ,Voltage-dependent anion channel ,Axonal degeneration ,Mitochondrion ,medicine.disease_cause ,ATP Binding Cassette Transporter, Subfamily D, Member 1 ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Mitochondrial biogenesis ,Internal medicine ,medicine ,Animals ,Humans ,Hypoglycemic Agents ,X-linked adrenoleukodystrophy ,Adrenoleukodystrophy ,030304 developmental biology ,Mice, Knockout ,0303 health sciences ,Pioglitazone ,biology ,Fatty Acids ,Neurodegeneration ,Original Articles ,Peroxisome ,medicine.disease ,Axons ,3. Good health ,Disease Models, Animal ,Oxidative Stress ,Glutathione Reductase ,Treatment Outcome ,Endocrinology ,Oxidative stress ,Nerve Degeneration ,biology.protein ,ATP-Binding Cassette Transporters ,Thiazolidinediones ,Neurology (clinical) ,030217 neurology & neurosurgery ,medicine.drug - Abstract
X-linked adrenoleukodystrophy is a neurometabolic disorder caused by inactivation of the peroxisomal ABCD1 transporter of very long-chain fatty acids. In mice, ABCD1 loss causes late onset axonal degeneration in the spinal cord in association with locomotor disability resembling the most common phenotype in patients, adrenomyeloneuropathy. Increasing evidence indicates that oxidative stress and bioenergetic failure play major roles in the pathogenesis of X-linked adrenoleukodystrophy. In this study, we aimed to evaluate whether mitochondrial biogenesis is affected in X-linked adrenoleukodystrophy. We demonstrated that Abcd1 null mice show reduced mitochondrial DNA concomitant with downregulation of mitochondrial biogenesis pathway driven by PGC-1α/PPARγ and reduced expression of mitochondrial proteins cytochrome c, NDUFB8 and VDAC. Moreover, we show that the oral administration of pioglitazone, an agonist of PPARγ, restored mitochondrial content and expression of master regulators of biogenesis, neutralized oxidative damage to proteins and DNA, and reversed bioenergetic failure in terms of ATP levels, NAD+/NADH ratios, pyruvate kinase and glutathione reductase activities. Most importantly, the treatment halted locomotor disability and axonal damage in X-linked adrenoleukodystrophy mice. These results lend support to the use of pioglitazone in clinical trials with patients with adrenomyeloneuropathy and reveal novel molecular mechanisms of action of pioglitazone in neurodegeneration. Future studies should address the effects of this anti-diabetic drug on other axonopathies in which oxidative stress and mitochondrial dysfunction are contributing factors. This work was supported by grants from the European Commission [FP7-241622], the European Leukodystrophy Association [ELA2009-036C5, ELA2008-040C4], the Spanish Institute for Health Carlos III [FIS PI11/01043], the Autonomous Government of Catalonia [2009SGR85 to A.P.], the Spanish Institute for Health Carlos III [Miguel Servet program CP11/ 00080 to S.F.], the COST action [BM0604 to A.P.]. S.F. was a fellow of the European Leukodystrophy Association [ELA 2010- 020F1]. L.M. is a fellow of the Spanish Ministry of Education [FPU program: AP2008-03728]. J.G. was a fellow of IDIBELL. The studies conducted at the Experimental Medicine Department were supported in part by R +D grants from the Spanish Ministry of Science and Innovation [BFU2009-11879/BFI], the Spanish Ministry of Health [PI081843], the Autonomous Government of Catalonia [2009SGR735], the ‘La Caixa’ Foundation and COST B35 Action of the European Union. The CIBER on Rare Diseases (CIBERER) and the CIBER on Neurodegenerative Diseases (CIBERNED) are initiatives of the ISCIII.
- Published
- 2013
34. Alterations in voltage-sensing of the mitochondrial permeability transition pore in ANT1-deficient cells
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Anikó Gál, Hibiki Kawamata, Beáta Töröcsik, Andoni Echaniz-Laguna, Mária Judit Molnár, Christos Chinopoulos, Giovanni Manfredi, Vera Adam-Vizi, Judit Doczi, Natalia N. Starkova, Anatoly A. Starkov, and Bénédicte Mousson de Camaret
- Subjects
0301 basic medicine ,Male ,Cell type ,Matrix (biology) ,Mitochondrial Membrane Transport Proteins ,Article ,03 medical and health sciences ,Mitochondrial membrane transport protein ,Humans ,Electrochemical gradient ,Calcimycin ,Cells, Cultured ,Membrane potential ,Membrane Potential, Mitochondrial ,Multidisciplinary ,biology ,Myogenesis ,Mitochondrial Permeability Transition Pore ,Cytochrome c ,Adenine Nucleotide Translocator 1 ,Hydrogen Peroxide ,Fibroblasts ,030104 developmental biology ,Biochemistry ,Mitochondrial permeability transition pore ,Gene Knockdown Techniques ,Mitochondrial Membranes ,biology.protein ,Biophysics ,Female - Abstract
The probability of mitochondrial permeability transition (mPT) pore opening is inversely related to the magnitude of the proton electrochemical gradient. The module conferring sensitivity of the pore to this gradient has not been identified. We investigated mPT’s voltage-sensing properties elicited by calcimycin or H2O2 in human fibroblasts exhibiting partial or complete lack of ANT1 and in C2C12 myotubes with knocked-down ANT1 expression. mPT onset was assessed by measuring in situ mitochondrial volume using the ‘thinness ratio’ and the ‘cobalt-calcein’ technique. De-energization hastened calcimycin-induced swelling in control and partially-expressing ANT1 fibroblasts, but not in cells lacking ANT1, despite greater losses of mitochondrial membrane potential. Matrix Ca2+ levels measured by X-rhod-1 or mitochondrially-targeted ratiometric biosensor 4mtD3cpv, or ADP-ATP exchange rates did not differ among cell types. ANT1-null fibroblasts were also resistant to H2O2-induced mitochondrial swelling. Permeabilized C2C12 myotubes with knocked-down ANT1 exhibited higher calcium uptake capacity and voltage-thresholds of mPT opening inferred from cytochrome c release, but intact cells showed no differences in calcimycin-induced onset of mPT, irrespective of energization and ANT1 expression, albeit the number of cells undergoing mPT increased less significantly upon chemically-induced hypoxia than control cells. We conclude that ANT1 confers sensitivity of the pore to the electrochemical gradient.
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- 2016
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35. Distinct Nrf2 Signaling Mechanisms of Fumaric Acid Esters and Their Role in Neuroprotection against 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine-Induced Experimental Parkinson's-Like Disease
- Author
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Manuj Ahuja, Bobby Thomas, Rajiv R. Ratan, N. A. Smirnova, Irina G. Gazaryan, Wendy B. Bollag, Noel Y. Calingasan, Lichuan Yang, M. Flint Beal, Irina N. Gaisina, Arsen Gaisin, John C. Morgan, Dmitry M. Hushpulian, Ismail Kaddour-Djebbar, Navneet Ammal Kaidery, and Anatoly A. Starkov
- Subjects
0301 basic medicine ,NF-E2-Related Factor 2 ,Biology ,Mitochondrion ,Pharmacology ,medicine.disease_cause ,Neuroprotection ,environment and public health ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Fumarates ,Parkinsonian Disorders ,Antigens, CD ,medicine ,Animals ,Humans ,Cell Line, Transformed ,Mice, Knockout ,Dose-Response Relationship, Drug ,General Neuroscience ,MPTP ,Neurodegeneration ,Maleates ,Glutathione ,Articles ,respiratory system ,medicine.disease ,KEAP1 ,Rats ,Mice, Inbred C57BL ,Disease Models, Animal ,030104 developmental biology ,Neuroprotective Agents ,chemistry ,Mitochondrial biogenesis ,Gene Expression Regulation ,1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine ,Tyrosine ,030217 neurology & neurosurgery ,Oxidative stress ,Signal Transduction - Abstract
A promising approach to neurotherapeutics involves activating the nuclear-factor-E2-related factor 2 (Nrf2)/antioxidant response element signaling, which regulates expression of antioxidant, anti-inflammatory, and cytoprotective genes. Tecfidera, a putative Nrf2 activator, is an oral formulation of dimethylfumarate (DMF) used to treat multiple sclerosis. We compared the effects of DMF and its bioactive metabolite monomethylfumarate (MMF) on Nrf2 signaling and their ability to block 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced experimental Parkinson9s disease (PD). We show that in vitro DMF and MMF activate the Nrf2 pathway via S-alkylation of the Nrf2 inhibitor Keap1 and by causing nuclear exit of the Nrf2 repressor Bach1. Nrf2 activation by DMF but not MMF was associated with depletion of glutathione, decreased cell viability, and inhibition of mitochondrial oxygen consumption and glycolysis rates in a dose-dependent manner, whereas MMF increased these activities in vitro. However, both DMF and MMF upregulated mitochondrial biogenesis in vitro in an Nrf2-dependent manner. Despite the in vitro differences, both DMF and MMF exerted similar neuroprotective effects and blocked MPTP neurotoxicity in wild-type but not in Nrf2 null mice. Our data suggest that DMF and MMF exhibit neuroprotective effects against MPTP neurotoxicity because of their distinct Nrf2-mediated antioxidant, anti-inflammatory, and mitochondrial functional/biogenetic effects, but MMF does so without depleting glutathione and inhibiting mitochondrial and glycolytic functions. Given that oxidative damage, neuroinflammation, and mitochondrial dysfunction are all implicated in PD pathogenesis, our results provide preclinical evidence for the development of MMF rather than DMF as a novel PD therapeutic. SIGNIFICANCE STATEMENT Almost two centuries since its first description by James Parkinson, Parkinson9s disease (PD) remains an incurable disease with limited symptomatic treatment. The current study provides preclinical evidence that a Food and Drug Administration-approved drug, dimethylfumarate (DMF), and its metabolite monomethylfumarate (MMF) can block nigrostriatal dopaminergic neurodegeneration in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mouse model of PD. We elucidated mechanisms by which DMF and its active metabolite MMF activates the redox-sensitive transcription factor nuclear-factor-E2-related factor 2 (Nrf2) to upregulate antioxidant, anti-inflammatory, mitochondrial biosynthetic and cytoprotective genes to render neuroprotection via distinct S-alkylating properties and depletion of glutathione. Our data suggest that targeting Nrf2-mediated gene transcription using MMF rather than DMF is a promising approach to block oxidative stress, neuroinflammation, and mitochondrial dysfunction for therapeutic intervention in PD while minimizing side effects.
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- 2016
36. Behavioral Improvement after Chronic Administration of Coenzyme Q10 in P301S Transgenic Mice
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Shari Jainuddin, Anatoly A. Starkov, Lichuan Yang, Cliona Stack, Ceyhan Elipenahli, Meri Gerges, Magali Dumont, and M. Flint Beal
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Male ,Genetically modified mouse ,medicine.medical_specialty ,Antioxidant ,Ubiquinone ,medicine.medical_treatment ,Transgene ,Mice, Transgenic ,tau Proteins ,Motor Activity ,Biology ,medicine.disease_cause ,Neuroprotection ,Article ,Lipid peroxidation ,Mice ,chemistry.chemical_compound ,Internal medicine ,medicine ,Animals ,Coenzyme Q10 ,General Neuroscience ,General Medicine ,Citric acid cycle ,Oxidative Stress ,Psychiatry and Mental health ,Clinical Psychology ,Endocrinology ,Electron Transport Chain Complex Proteins ,chemistry ,Frontotemporal Dementia ,Mutation ,Female ,Geriatrics and Gerontology ,Oxidative stress - Abstract
Coenzyme Q10 is a key component of the electron transport chain which plays an essential role in ATP production and also has antioxidant effects. Neuroprotective effects of coenzyme Q10 have been reported in both in vitro and in vivo models of neurodegenerative diseases. However, its effects have not been studied in cells or in animals with tau induced pathology. In this report, we administered coenzyme Q10 to transgenic mice with the P301S tau mutation, which causes fronto-temporal dementia in man. These mice develop tau hyperphosphorylation and neurofibrillary tangles in the brain. Coenzyme Q10 improved survival and behavioral deficits in the P301S mice. There was a modest reduction in phosphorylated tau in the cortex of P301S mice. We also examined the effects of coenzyme Q10 treatment on the electron transport chain enzymes, the mitochondrial antioxidant enzymes, and the tricarboxylic acid cycle. There was a significant increase in complex I activity and protein levels, and a reduction in lipid peroxidation. Our data show that coenzyme Q10 significantly improved behavioral deficits and survival in transgenic mice with the P301S tau mutation, upregulated key enzymes of the electron transport chain, and reduced oxidative stress.
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- 2012
37. Evaluation of the toxicity of fungicides to flight muscle mitochondria of bumblebee (Bombus terrestris L.)
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Vasily N. Popov, Anastasia V. Kokina, Anatoly A. Starkov, A. V. Lopatin, and Mikhail Y. Syromyatnikov
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0301 basic medicine ,Male ,Health, Toxicology and Mutagenesis ,Dehydrogenase ,Glycerolphosphate Dehydrogenase ,010501 environmental sciences ,Mitochondrion ,Fludioxonil ,01 natural sciences ,Electron Transport ,03 medical and health sciences ,Botany ,Respiration ,Animals ,Bumblebee ,0105 earth and related environmental sciences ,Membrane Potential, Mitochondrial ,Electron Transport Complex I ,biology ,Succinate dehydrogenase ,NADH Dehydrogenase ,General Medicine ,Bees ,biology.organism_classification ,Fungicides, Industrial ,Mitochondria, Muscle ,Fungicide ,Succinate Dehydrogenase ,030104 developmental biology ,Bombus terrestris ,Glycerophosphates ,biology.protein ,Insect Proteins ,Reactive Oxygen Species ,Agronomy and Crop Science - Abstract
Insects pollinate 75% of crops used for human consumption. Over the last decade, a substantial reduction in the abundance of pollinating insects has been recorded and recognized as a severe matter for food supply security. Many of the important food crops destined for human consumption are grown in greenhouses. A unique feature of greenhouse agriculture is the extensive use of fungicides to curb multiple fungal infections. The most widely used pollinating insects in greenhouses are commercially reared bumblebees. However, there is no data regarding the toxicity of fungicides to bumblebee mitochondria. To fill this gap in knowledge, we examined the effects of 16 widely used fungicides on the energetics of the flight muscles mitochondria of Bombus terrestris. We found that diniconazole and fludioxonil uncoupled the respiration of mitochondria; dithianon and difenoconazole inhibited it. By analyzing the action of these inhibitors on mitochondrial respiration and generation of reactive oxygen species, we concluded that difenoconazole inhibited electron transport at the level of Complex I and glycerol-3-phosphate dehydrogenase. Dithianon strongly inhibited succinate dehydrogenase and glycerol-3-phosphate dehydrogenase. It also strongly inhibited mitochondrial oxidation of NAD-linked substrates or glycerol 3-phosphate, but it had no effect on the enzymatic activity of Complex I. It may be suggested that dithianon inhibits electron transport downstream of Complex I, likely at multiply sites.
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- 2015
38. In VivoPathogenic Role of Mutant SOD1 Localized in the Mitochondrial Intermembrane Space
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Jordi Magrané, Isabel Hervias, Magali Dumont, Czrina Cortez, Hyun Jeong Kim, Jonathan D. Glass, Anissa Igoudjil, Giovanni Manfredi, Anatoly A. Starkov, and Lindsey R. Fischer
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Male ,Mitochondrial intermembrane space ,Mutant ,SOD1 ,Mice, Transgenic ,Nerve Tissue Proteins ,Kaplan-Meier Estimate ,Mitochondrion ,Biology ,Article ,Mice ,Superoxide Dismutase-1 ,Microscopy, Electron, Transmission ,medicine ,Animals ,Humans ,Amyotrophic lateral sclerosis ,Muscle, Skeletal ,Analysis of Variance ,Superoxide Dismutase ,Myocardium ,General Neuroscience ,Amyotrophic Lateral Sclerosis ,Body Weight ,Neurodegeneration ,Brain ,nutritional and metabolic diseases ,Heart ,Motor neuron ,medicine.disease ,Mitochondria ,nervous system diseases ,Cell biology ,Disease Models, Animal ,medicine.anatomical_structure ,Spinal Cord ,nervous system ,Biochemistry ,Mutation ,Calcium ,Energy Metabolism ,Intermembrane space - Abstract
Mutations in Cu,Zn superoxide dismutase (SOD1) are associated with familial amyotrophic lateral sclerosis (ALS). Mutant SOD1 causes a complex array of pathological events, through toxic gain of function mechanisms, leading to selective motor neuron degeneration. Mitochondrial dysfunction is among the well established toxic effects of mutant SOD1, but its mechanisms are just starting to be elucidated. A portion of mutant SOD1 is localized in mitochondria, where it accumulates mostly on the outer membrane and inside the intermembrane space (IMS). Evidence in cultured cells suggests that mutant SOD1 in the IMS causes mitochondrial dysfunction and compromises cell viability. Therefore, to test its pathogenic rolein vivowe generated transgenic mice expressing G93A mutant or wild-type (WT) human SOD1 targeted selectively to the mitochondrial IMS (mito-SOD1). We show that mito-SOD1 is correctly localized in the IMS, where it oligomerizes and acquires enzymatic activity. Mito-G93ASOD1 mice, but not mito-WTSOD1 mice, develop a progressive disease characterized by body weight loss, muscle weakness, brain atrophy, and motor impairment, which is more severe in females. These symptoms are associated with reduced spinal motor neuron counts and impaired mitochondrial bioenergetics, characterized by decreased cytochrome oxidase activity and defective calcium handling. However, there is no evidence of muscle denervation, a cardinal pathological feature of ALS. Together, our findings indicate that mutant SOD1 in the mitochondrial IMS causes mitochondrial dysfunction and neurodegeneration, butper seit is not sufficient to cause a full-fledged ALS phenotype, which requires the participation of mutant SOD1 localized in other cellular compartments.
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- 2011
39. Behavioral deficit, oxidative stress, and mitochondrial dysfunction precede tau pathology in P301S transgenic mice
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Magali Dumont, Natalia N. Starkova, Cliona Stack, Ceyhan Elipenahli, Flint Beal, Meri Gerges, Lichuan Yang, Anatoly A. Starkov, and Shari Jainuddin
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Male ,Aging ,medicine.medical_specialty ,Citric Acid Cycle ,Spatial Behavior ,Mice, Transgenic ,Mitochondrion ,medicine.disease_cause ,Biochemistry ,Research Communications ,Electron Transport ,Glycogen Synthase Kinase 3 ,Mice ,GSK-3 ,Internal medicine ,Genetics ,medicine ,Animals ,Citrate synthase ,Cytochrome c oxidase ,Molecular Biology ,GSK3B ,Glycogen Synthase Kinase 3 beta ,Behavior, Animal ,biology ,Neurodegeneration ,medicine.disease ,Mitochondria ,Oxidative Stress ,Endocrinology ,Tauopathies ,Exploratory Behavior ,biology.protein ,Female ,Tauopathy ,Reactive Oxygen Species ,Locomotion ,Oxidative stress ,Biotechnology - Abstract
Abnormal tau accumulation can lead to the development of neurodegenerative diseases. P301S mice overexpress the human tau mutated gene, resulting in tau hyperphosphorylation and tangle formation. Mice also develop synaptic deficits and microglial activation prior to any neurodegeneration and tangles. Oxidative stress can also affect tauopathy. We studied the role of oxidative stress in relationship to behavioral abnormalities and disease progression in P301S mice at 2, 7, and 10 mo of age. At 7 mo of age, P301S mice had behavioral abnormalities, such as hyperactivity and disinhibition. At the same age, we observed increased carbonyls in P301S mitochondria (∼215 and 55% increase, males/females), and deregulation in the activity and content of mitochondrial enzymes involved in reactive oxygen species formation and energy metabolism, such as citrate synthase (∼19 and ∼5% decrease, males/females), MnSOD (∼16% decrease, males only), cytochrome C (∼19% decrease, females only), and cytochrome C oxidase (∼20% increase, females only). These changes in mitochondria proteome appeared before tau hyperphosphorylation and tangle formation, which were observed at 10 mo and were associated with GSK3β activation. At that age, mitochondria proteome deregulation became more apparent in male P301S mitochondria. The data strongly suggest that oxidative stress and mitochondrial abnormalities appear prior to tau pathology.—Dumont, M., Stack, C., Elipenahli, C., Jainuddin, S., Gerges, M., Starkova, M. N., Yang, L., Starkov, A. A., Beal, F. Behavioral deficit, oxidative stress, and mitochondrial dysfunction precede tau pathology in P301S transgenic mice.
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- 2011
40. Modulation of F0F1-ATP synthase activity by cyclophilin D regulates matrix adenine nucleotide levels
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Csaba Konrad, Anatoly A. Starkov, Christos Chinopoulos, Gergely Kiss, Steven F. Zhang, Eugeniy Metelkin, and Beáta Töröcsik
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Membrane potential ,ATP synthase ,biology ,Cell Biology ,Mitochondrion ,Biochemistry ,Molecular biology ,ANT ,Adenine nucleotide ,Cyclosporin a ,biology.protein ,Phosphorylation ,Submitochondrial particle ,Molecular Biology - Abstract
Cyclophilin D was recently shown to bind to and decrease the activity of F(0)F(1)-ATP synthase in submitochondrial particles and permeabilized mitochondria [Giorgio V et al. (2009) J Biol Chem, 284, 33982-33988]. Cyclophilin D binding decreased both ATP synthesis and hydrolysis rates. In the present study, we reaffirm these findings by demonstrating that, in intact mouse liver mitochondria energized by ATP, the absence of cyclophilin D or the presence of cyclosporin A led to a decrease in the extent of uncoupler-induced depolarization. Accordingly, in substrate-energized mitochondria, an increase in F(0)F(1)-ATP synthase activity mediated by a relief of inhibition by cyclophilin D was evident in the form of slightly increased respiration rates during arsenolysis. However, the modulation of F(0)F(1)-ATP synthase by cyclophilin D did not increase the adenine nucleotide translocase (ANT)-mediated ATP efflux rate in energized mitochondria or the ATP influx rate in de-energized mitochondria. The lack of an effect of cyclophilin D on the ANT-mediated adenine nucleotide exchange rate was attributed to the ∼ 2.2-fold lower flux control coefficient of the F(0)F(1)-ATP synthase than that of ANT, as deduced from measurements of adenine nucleotide flux rates in intact mitochondria. These findings were further supported by a recent kinetic model of the mitochondrial phosphorylation system, suggesting that an ∼ 30% change in F(0)F(1)-ATP synthase activity in fully energized or fully de-energized mitochondria affects the ADP-ATP exchange rate mediated by the ANT in the range 1.38-1.7%. We conclude that, in mitochondria exhibiting intact inner membranes, the absence of cyclophilin D or the inhibition of its binding to F(0)F(1)-ATP synthase by cyclosporin A will affect only matrix adenine nucleotides levels.
- Published
- 2011
41. A kinetic assay of mitochondrial ADP–ATP exchange rate in permeabilized cells
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Christos Chinopoulos, Hibiki Kawamata, Giovanni Manfredi, and Anatoly A. Starkov
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Biophysics ,Citrate (si)-Synthase ,Mitochondrion ,Biochemistry ,Article ,Permeability ,Cell Line ,Myoblasts ,Fluorides ,Mice ,chemistry.chemical_compound ,Adenosine Triphosphate ,Adenine nucleotide ,Animals ,Citrate synthase ,Magnesium ,Molecular Biology ,Membrane Potential, Mitochondrial ,biology ,Adenine nucleotide translocator ,Intracellular Membranes ,Cell Biology ,Mitochondria ,Adenosine Diphosphate ,Kinetics ,Proton-Translocating ATPases ,Adenosine diphosphate ,Digitonin ,chemistry ,biology.protein ,Beryllium ,ATP–ADP translocase ,Vanadates ,Mitochondrial ADP, ATP Translocases ,Adenosine triphosphate - Abstract
We previously described a method to measure ADP-ATP exchange rates in isolated mitochondria by recording the changes in free extramitochondrial [Mg(2+)] reported by an Mg(2+)-sensitive fluorescent indicator, exploiting the differential affinity of ADP and ATP to Mg(2+). In the current article, we describe a modification of this method suited for following ADP-ATP exchange rates in environments with competing reactions that interconvert adenine nucleotides such as in permeabilized cells that harbor phosphorylases and kinases, ion pumps exhibiting substantial ATPase activity, and myosin ATPase activity. Here we report that the addition of BeF(3)(-) and sodium orthovanadate (Na(3)VO(4)) to medium containing digitonin-permeabilized cells inhibits all ADP-ATP-using reactions except the adenine nucleotide translocase (ANT)-mediated mitochondrial ADP-ATP exchange. An advantage of this assay is that mitochondria that may have been also permeabilized by digitonin do not contribute to ATP consumption by the exposed F(1)F(o)-ATPase due to its sensitivity to BeF(3)(-) and Na(3)VO(4). With this assay, ADP-ATP exchange rate mediated by the ANT in permeabilized cells is measured for the entire range of mitochondrial membrane potential titrated by stepwise additions of an uncoupler and expressed as a function of citrate synthase activity per total amount of protein.
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- 2010
42. The molecular identity of the mitochondrial Ca2+ sequestration system
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Anatoly A. Starkov
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Programmed cell death ,biology ,Excitotoxicity ,chemistry.chemical_element ,Cell Biology ,Mitochondrion ,Calcium ,medicine.disease_cause ,Biochemistry ,Cell biology ,Mitochondrial membrane transport protein ,chemistry ,Mitochondrial permeability transition pore ,Mitochondrial matrix ,biology.protein ,medicine ,Molecular Biology ,Calcium signaling - Abstract
There is ample evidence to suggest that a dramatic decrease in mitochondrial Ca2+ retention may contribute to the cell death associated with stroke, excitotoxicity, ischemia and reperfusion, and neurodegenerative diseases. Mitochondria from all studied tissues can accumulate and store Ca2+, but the maximum Ca2+ storage capacity varies widely and exhibits striking tissue specificity. There is currently no explanation for this fact. Precipitation of Ca2+ and phosphate in the mitochondrial matrix has been suggested to be the major form of storage of accumulated Ca2+ in mitochondria. How this precipitate is formed is not known. The molecular identity of almost all proteins involved in Ca2+ transport, storage and formation of the permeability transition pore is also unknown. This review summarizes studies aimed at identifying these proteins, and describes the properties of a known mitochondrial protein that may be involved in Ca2+ transport and the structure of the permeability transition pore.
- Published
- 2010
43. Methylenedioxymethamphetamine inhibits mitochondrial complex I activity in mice: a possible mechanism underlying neurotoxicity
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Isabel Hervias, Joaquín Jordán, Elena Puerta, Anatoly A. Starkov, Steven F. Zhang, Beatriz Goñi-Allo, and Norberto Aguirre
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Pharmacology ,Chemistry ,Superoxide ,Dopaminergic ,Neurotoxicity ,Substantia nigra ,Glutathione ,Mitochondrion ,medicine.disease_cause ,medicine.disease ,chemistry.chemical_compound ,Biochemistry ,Dopamine ,medicine ,Oxidative stress ,medicine.drug - Abstract
Background and purpose: 3,4-methylenedioxymethamphetamine (MDMA) causes a persistent loss of dopaminergic cell bodies in the substantia nigra of mice. Current evidence indicates that such neurotoxicity is due to oxidative stress but the source of free radicals remains unknown. Inhibition of mitochondrial electron transport chain complexes by MDMA was assessed as a possible source. Experimental approach: Activities of mitochondrial complexes after MDMA were evaluated spectrophotometrically. In situ visualization of superoxide production in the striatum was assessed by ethidium fluorescence and striatal dopamine levels were determined by HPLC as an index of dopaminergic toxicity. Key results: 3,4-methylenedioxymethamphetamine decreased mitochondrial complex I activity in the striatum of mice, an effect accompanied by an increased production of superoxide radicals and the inhibition of endogenous aconitase. α-Lipoic acid prevented superoxide generation and long-term toxicity independent of any effect on complex I inhibition. These effects of α-lipoic acid were also associated with a significant increase of striatal glutathione levels. The relevance of glutathione was supported by reducing striatal glutathione content with L-buthionine-(S,R)-sulfoximine, which exacerbated MDMA-induced dopamine deficits, effects suppressed by α-lipoic acid. The nitric oxide synthase inhibitor, NG-nitro-L-arginine, partially prevented MDMA-induced dopamine depletions, an effect reversed by L-arginine but not D-arginine. Finally, a direct relationship between mitochondrial complex I inhibition and long-term dopamine depletions was found in animals treated with MDMA in combination with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Conclusions and implications: Inhibition of mitochondrial complex I following MDMA could be the source of free radicals responsible for oxidative stress and the consequent neurotoxicity of this drug in mice. This article is commented on by Moncada, pp. 217–219 of this issue. To view this commentary visit http://dx.doi.org/10.1111/j.1476-5381.2010.00706.x and to view related papers in this issue by Pravdic et al. and Kurz et al. visit http://dx.doi.org/10.1111/j.1476-5381.2010.00698.x and http://dx.doi.org/10.1111/j.1476-5381.2010.00656.x
- Published
- 2010
44. Complement Component C1q Mediates Mitochondria-Driven Oxidative Stress in Neonatal Hypoxic–Ischemic Brain Injury
- Author
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David J. Pinsky, Anatoly A. Starkov, Samuel C. Silverstein, Baalasubramanian Sivasankar, Veniamin Ratner, Raymond I. Stark, Deborah A. Fraser, Vadim S. Ten, Jun Yao, B. Paul Morgan, Richard A. Polin, Sergey A. Sosunov, Marina Botto, and Susan J. Vannucci
- Subjects
Brain Infarction ,Mitochondrial ROS ,Respiratory chain ,CD59 Antigens ,chemical and pharmacologic phenomena ,Mitochondrion ,Biology ,urologic and male genital diseases ,medicine.disease_cause ,Neuroprotection ,Article ,Mice ,Cytosol ,fluids and secretions ,immune system diseases ,medicine ,Animals ,skin and connective tissue diseases ,Complement Activation ,Cells, Cultured ,Mice, Knockout ,Neurons ,chemistry.chemical_classification ,Reactive oxygen species ,Complement C1q ,General Neuroscience ,R1 ,Mitochondria ,Complement system ,Cell biology ,Mice, Inbred C57BL ,Oxygen ,Oxidative Stress ,Glucose ,Animals, Newborn ,chemistry ,Hypoxia-Ischemia, Brain ,Immunology ,RC0321 ,Female ,Reactive Oxygen Species ,Complement membrane attack complex ,Oxidative stress - Abstract
Hypoxic–ischemic (HI) brain injury in infants is a leading cause of lifelong disability. We report a novel pathway mediating oxidative brain injury after hypoxia–ischemia in which C1q plays a central role. Neonatal mice incapable of classical or terminal complement activation because of C1q or C6 deficiency or pharmacologically inhibited assembly of membrane attack complex were subjected to hypoxia–ischemia. Only C1q−/−mice exhibited neuroprotection coupled with attenuated oxidative brain injury. This was associated with reduced production of reactive oxygen species (ROS) in C1q−/−brain mitochondria and preserved activity of the respiratory chain. Compared with C1q+/+neurons, cortical C1q−/−neurons exhibited resistance to oxygen–glucose deprivation. However, postischemic exposure to exogenous C1q increased both mitochondrial ROS production and mortality of C1q−/−neurons. This C1q toxicity was abolished by coexposure to antioxidant Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid). Thus, the C1q component of complement, accelerating mitochondrial ROS emission, exacerbates oxidative injury in the developing HI brain. The terminal complement complex is activated in the HI neonatal brain but appeared to be nonpathogenic. These findings have important implications for design of the proper therapeutic interventions against HI neonatal brain injury by highlighting a pathogenic priority of C1q-mediated mitochondrial oxidative stress over the C1q deposition-triggered terminal complement activation.
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- 2010
45. Cause and consequence: Mitochondrial dysfunction initiates and propagates neuronal dysfunction, neuronal death and behavioral abnormalities in age-associated neurodegenerative diseases
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Rajiv R. Ratan, John P. Blass, Anatoly A. Starkov, Gary E. Gibson, and M. Flint Beal
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medicine.medical_specialty ,Cell signaling ,Programmed cell death ,Tissue transglutaminase ,α-ketoglutarate dehydrogenase ,Oxidative phosphorylation ,Mitochondrion ,medicine.disease_cause ,Article ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,Animals ,Humans ,Cognitive decline ,Molecular Biology ,030304 developmental biology ,Neurons ,chemistry.chemical_classification ,0303 health sciences ,Reactive oxygen species ,Transglutaminases ,Cell Death ,biology ,Neurodegenerative Diseases ,Transglutaminase ,Mitochondria ,3. Good health ,Endocrinology ,chemistry ,Oxidative stress ,biology.protein ,Reactive oxygen specie ,Molecular Medicine ,Calcium ,Reactive Oxygen Species ,030217 neurology & neurosurgery - Abstract
Age-related neurodegenerative diseases are associated with mild impairment of oxidative metabolism and accumulation of abnormal proteins. Within the cell, the mitochondria appears to be a dominant site for initiation and propagation of disease processes. Shifts in metabolism in response to mild metabolic perturbations may decrease the threshold for irreversible injury in response to ordinarily sublethal metabolic insults. Mild impairment of metabolism accrue from and lead to increased reactive oxygen species (ROS). Increased ROS change cell signaling via post-transcriptional and transcriptional changes. The cause and consequences of mild impairment of mitochondrial metabolism is one focus of this review. Many experiments in tissues from humans support the notion that oxidative modification of the α-ketoglutarate dehydrogenase complex (KGDHC) compromises neuronal energy metabolism and enhances ROS production in Alzheimer's Disease (AD). These data suggest that cognitive decline in AD derives from the selective tricarboxylic acid (TCA) cycle abnormalities. By contrast in Huntington's Disease (HD), a movement disorder with cognitive features distinct form AD, complex II+III abnormalities may dominate. These distinct mitochondrial abnormalities culminate in oxidative stress, energy dysfunction, and aberrant homeostasis of cytosolic calcium. Cytosolic calcium, elevations even only transiently, leads to hyperactivity of a number of enzymes. One calcium-activated enzyme with demonstrated pathophysiological import in HD and AD is transglutaminase (TGase). TGase is a crosslinking enzymes that can modulate transcription, inactivate metabolic enzymes, and cause aggregation of critical proteins. Recent data indicate that TGase can silence expression of genes involved in compensating for metabolic stress. Altogether, our results suggest that increasing KGDHC via inhibition of TGase or via a host of other strategies to be described would be effective therapeutic approaches in age-associated neurodegenerative diseases.
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- 2010
46. Promethazine protects against 3-nitropropionic acid-induced neurotoxicity
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Noel Y. Calingasan, Emmanuel Brouillet, Carine Cleren, Carine Jacquard, Anatoly A. Starkov, M. Flint Beal, and Junya Chen
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Male ,medicine.medical_specialty ,Striatum ,Promethazine ,Neuroprotection ,Article ,Brain Ischemia ,Mice ,Cellular and Molecular Neuroscience ,In vivo ,Internal medicine ,medicine ,Animals ,business.industry ,Amyotrophic Lateral Sclerosis ,Neurotoxicity ,Cell Biology ,Nitro Compounds ,medicine.disease ,Rats ,Succinate Dehydrogenase ,Disease Models, Animal ,Huntington Disease ,Neuroprotective Agents ,Endocrinology ,Mitochondrial permeability transition pore ,Rats, Inbred Lew ,Apoptosis ,Toxicity ,Propionates ,business ,medicine.drug - Abstract
Promethazine (PMZ), an FDA-approved antihistaminergic drug, was identified as a potentially neuroprotective compound in a NINDS screening program. It was shown to protect against ischemia in mice, to delay disease onset in a mouse model of amyotrophic lateral sclerosis and to inhibit Ca(2+)-induced mitochondrial permeability transition in rat liver mitochondria. We investigated whether PMZ could protect against the neurotoxic effects induced by 3-nitropropionic acid (3-NP), an inhibitor of the succinate dehydrogenase, used to model Huntington's disease (HD) in rats. Lewis rats receiving chronic subcutaneous infusion of 3-NP were treated with PMZ. The findings indicate that chronic PMZ treatment significantly reduced 3-NP-induced striatal lesion volume, loss of GABAergic neurons and number of apoptotic cells in the striatum. PMZ showed a strong neuroprotective effect against 3-NP toxicity in vivo.
- Published
- 2010
47. Mice deficient in dihydrolipoyl succinyl transferase show increased vulnerability to mitochondrial toxins
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Elizabeth Wille, Hui Xu, Noel Y. Calingasan, Huan-Lian Chen, Daniel J. Ho, Steven F. Zhang, Lichuan Yang, Anatoly A. Starkov, Gary E. Gibson, Cliona Stack, M. Flint Beal, and Qingli Shi
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Male ,Huntington ,Neurotoxins ,Substantia nigra ,Biology ,Mitochondrion ,Article ,lcsh:RC321-571 ,Mice ,chemistry.chemical_compound ,Enzyme activator ,Oxidative damage ,Animals ,Transferase ,Genetic Predisposition to Disease ,Ketoglutarate Dehydrogenase Complex ,Parkinson ,Tyrosine ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,Mice, Knockout ,Pars compacta ,MPTP ,Brain ,Neurodegenerative Diseases ,Molecular biology ,Mitochondria ,Enzyme Activation ,Isoenzymes ,Mice, Inbred C57BL ,Citric acid cycle ,nervous system ,Neurology ,chemistry ,Female ,Coenzyme A-Transferases ,α-ketoglutarate dehydrogenase complex ,Energy Metabolism - Abstract
The activity of a key mitochondrial tricarboxylic acid cycle enzyme, alpha-ketoglutarate dehydrogenase complex (KGDHC), declines in many neurodegenerative diseases. KGDHC consists of three subunits. The dihydrolipoyl succinyl transferase (DLST) component is unique to KGDHC. DLST(+/-) mice showed reduced mRNA and protein levels and decreased brain mitochondrial KGDHC activity. Neurotoxic effects of mitochondrial toxins were exacerbated in DLST(+/-) mice. MPTP produced a significantly greater reduction of striatal dopamine and tyrosine hydroxylase-positive neurons in the substantia nigra pars compacta of DLST(+/-) mice. DLST deficiency enhanced the severity of lipid peroxidation in the substantia nigra after MPTP treatment. Striatal lesions induced by either malonate or 3-nitropropionic acid (3-NP) were significantly larger in DLST(+/-) mice than in wildtype controls. DLST deficiency enhanced the 3-NP inhibition of mitochondria enzymes, and 3-NP induced protein and DNA oxidations. These observations support the hypothesis that reductions in KGDHC may impair the adaptability of the brain and contribute to the pathogenesis of neurodegenerative diseases.
- Published
- 2009
48. Impaired PGC-1α function in muscle in Huntington's disease
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Mahmoud Kiaei, Lichuan Yang, S. Shukla, Andrea Ciammola, Anatoly A. Starkov, Jenny Sassone, M. Flint Beal, Thomas Hennessy, Noel Y. Calingasan, Peter J. Adhihetty, Milena Cannella, Rajnish Kumar Chaturvedi, and Fernando Squitieri
- Subjects
medicine.medical_specialty ,Huntingtin ,Gene Expression ,Mice, Transgenic ,AMP-Activated Protein Kinases ,Mitochondrion ,Creatine ,Myoblasts ,Mice ,chemistry.chemical_compound ,AMP-activated protein kinase ,Internal medicine ,Genetics ,medicine ,Animals ,Humans ,Myocyte ,NRF1 ,Muscle, Skeletal ,Molecular Biology ,Cells, Cultured ,Heat-Shock Proteins ,Genetics (clinical) ,biology ,AMPK ,Articles ,General Medicine ,Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha ,Disease Models, Animal ,Huntington Disease ,Endocrinology ,Mitochondrial biogenesis ,chemistry ,biology.protein ,Transcription Factors - Abstract
We investigated the role of PPAR gamma coactivator 1alpha (PGC-1alpha) in muscle dysfunction in Huntington's disease (HD). We observed reduced PGC-1alpha and target genes expression in muscle of HD transgenic mice. We produced chronic energy deprivation in HD mice by administering the catabolic stressor beta-guanidinopropionic acid (GPA), a creatine analogue that reduces ATP levels, activates AMP-activated protein kinase (AMPK), which in turn activates PGC-1alpha. Treatment with GPA resulted in increased expression of AMPK, PGC-1alpha target genes, genes for oxidative phosphorylation, electron transport chain and mitochondrial biogenesis, increased oxidative muscle fibers, numbers of mitochondria and motor performance in wild-type, but not in HD mice. In muscle biopsies from HD patients, there was decreased PGC-1alpha, PGC-1beta and oxidative fibers. Oxygen consumption, PGC-1alpha, NRF1 and response to GPA were significantly reduced in myoblasts from HD patients. Knockdown of mutant huntingtin resulted in increased PGC-1alpha expression in HD myoblast. Lastly, adenoviral-mediated delivery of PGC-1alpha resulted increased expression of PGC-1alpha and markers for oxidative muscle fibers and reversal of blunted response for GPA in HD mice. These findings show that impaired function of PGC-1alpha plays a critical role in muscle dysfunction in HD, and that treatment with agents to enhance PGC-1alpha function could exert therapeutic benefits. Furthermore, muscle may provide a readily accessible tissue in which to monitor therapeutic interventions.
- Published
- 2009
49. Mitochondrial Dysfunction Contributes to Alveolar Developmental Arrest in Hyperoxia-Exposed Mice
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Richard A. Polin, Dzmitry Matsiukevich, Veniamin Ratner, Vadim S. Ten, and Anatoly A. Starkov
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Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,Pathology ,Bioenergetics ,Cellular respiration ,Cell Respiration ,Clinical Biochemistry ,Oxidative phosphorylation ,Hyperoxia ,Biology ,Mitochondrion ,Mice ,Internal medicine ,Respiration ,medicine ,Animals ,Molecular Biology ,Electron Transport Complex I ,Lung ,Cell Biology ,respiratory system ,medicine.disease ,Mitochondria ,Mice, Inbred C57BL ,Pulmonary Alveoli ,Endocrinology ,medicine.anatomical_structure ,Bronchopulmonary dysplasia ,medicine.symptom ,Rapid Communication - Abstract
This study investigated whether mitochondrial dysfunction contributes to alveolar developmental arrest in a mouse model of bronchopulmonary dysplasia (BPD). To induce BPD, 3-day-old mice were exposed to 75% O2. Mice were studied at two time points of hyperoxia (72 h or 2 wk) and after 3 weeks of recovery in room air (RA). A separate cohort of mice was exposed to pyridaben, a complex-I (C-I) inhibitor, for 72 hours or 2 weeks. Alveolarization was quantified by radial alveolar count and mean linear intercept methods. Pulmonary mitochondrial function was defined by respiration rates, ATP-production rate, and C-I activity. At 72 hours, hyperoxic mice demonstrated significant inhibition of C-I activity, reduced respiration and ATP production rates, and significantly decreased radial alveolar count compared with controls. Exposure to pyridaben for 72 hours, as expected, caused significant inhibition of C-I and ADP-phosphorylating respiration. Similar to hyperoxic littermates, these pyridaben-exposed mice exhibited significantly delayed alveolarization compared with controls. At 2 weeks of exposure to hyperoxia or pyridaben, mitochondrial respiration was inhibited and associated with alveolar developmental arrest. However, after 3 weeks of recovery from hyperoxia or 2 weeks after 72 hours of exposure to pyridaben alveolarization significantly improved. In addition, there was marked normalization of C-I and mitochondrial respiration. The degree of hyperoxia-induced pulmonary simplification and recovery strongly (r(2) = 0.76) correlated with C-I activity in lung mitochondria. Thus, the arrest of alveolar development induced by either hyperoxia or direct inhibition of mitochondrial oxidative phosphorylation indicates that bioenergetic failure to maintain normal alveolar development is one of the fundamental mechanisms responsible for BPD.
- Published
- 2009
50. 24th International Workshop on Surfactant Replacement, Ljubljana, June 4–6, 2009
- Author
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Tibor Ertl, Judit Gyarmati, Chad C. Andersen, Dominic Wilkinson, Claudio De Felice, Tore Curstedt, Roger F. Soll, Michele R. Hacker, Linda J. Jacobson, Fang Sun, Hiroyuki Mochizuki, Yasushi Ohki, Vadim S. Ten, Po-Yin Cheung, Siarhei Slinko, William W. Hay, Kenichi Tokuyama, Sture Andersson, Hiroo Mayuzumi, Marta Aguar, Deborah L. Harris, Federica Chiellini, Olli Pitkänen, Christian P. Speer, Ingemar Ingemarsson, Jane E. Harding, Malcolm R. Battin, Otto Helve, Anjali Parish, Iris Morag, Kazuo Momma, Philip J. Weston, Antonio Del Vecchio, Akihiro Morikawa, Chris E. Williams, Jacob Kuint, Henry L. Halliday, Gabriella Vida, Mikko Hallman, Richard A. Polin, Marcella Ferri, Cecilia Janér, Giuseppe Latini, Toshio Nakanishi, Katsuaki Toyoshima, Gábor L. Kovács, Irina Utkina-Sosunova, Anatoly A. Starkov, Margit Tokes-Fuzesi, Jatinder Bhatia, Ayala Maayan-Metzger, Hirokazu Arakawa, Marilyn J. Manco-Johnson, Yukihiro Yoshizawa, Ola Didrik Saugstad, Veniamin Ratner, Janez Babnik, Alessandro Barducci, Valéria Gaál, Máximo Vento, and Moran Barak
- Subjects
medicine.medical_specialty ,Pediatrics ,business.industry ,General surgery ,Pediatrics, Perinatology and Child Health ,Medicine ,Surfactant replacement ,business ,Developmental Biology - Published
- 2009
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