scholarly journals Mechanisms of mitochondrial response to variations in energy demand in eukaryotic cells

2007 ◽  
Vol 292 (1) ◽  
pp. C52-C58 ◽  
Author(s):  
Anne Devin ◽  
Michel Rigoulet
Keyword(s):  
Oxidative Phosphorylation ◽  
Energy Demand ◽  
Covalent Modification ◽  
Eukaryotic Cells ◽  
Heart Cells ◽  
Mitochondrial Enzyme ◽  
Atp Production ◽  
Enzyme Content ◽  
Mitochondrial Atp Synthase ◽  
Kinetic Regulation

This review focuses on the different mechanisms involved in the adjustment of mitochondrial ATP production to cellular energy demand. The oxidative phosphorylation steady state at constant mitochondrial enzyme content can vary in response to energy demand. However, such an adaptation is tightly linked to a modification in both oxidative phosphorylation yield and phosphate potential and is obviously very limited in eukaryotic cells. We describe the three main mechanisms involved in mitochondrial response to energy demand. In heart cells, a short-term adjustment can be reached mainly through metabolic signaling via phosphotransfer networks by the compartmentalized energy transfer and signal transmission. In such a complex regulatory mechanism, Ca2+signaling participates in activation of matricial dehydrogenases as well as mitochondrial ATP synthase. These processes allow a large increase in ATP production rate without an important modification in thermodynamic forces. For a long-term adaptation, two main mechanisms are involved: modulation of the mitochondrial enzyme content as a function of energy demand and/or kinetic regulation by covalent modifications (phosphorylations) of some respiratory chain complex subunits. Regardless of the mechanism involved (kinetic regulation by covalent modification or adjustment of mitochondrial enzyme content), the cAMP signaling pathway plays a major role in molecular signaling, leading to the mitochondrial response. We discuss the energetic advantages of these mechanisms.

scholarly journals Regulation of ATP supply during muscle contraction: theoretical studies

1998 ◽  
Vol 330 (3) ◽  
pp. 1189-1195 ◽  
Author(s):  
Bernard KORZENIEWSKI
Keyword(s):  
Oxidative Phosphorylation ◽  
Muscle Contraction ◽  
Respiration Rate ◽  
Energy Demand ◽  
Large Scale ◽  
Minor Role ◽  
Atp Production ◽  
Direct Activation ◽  
Metabolite Concentrations ◽  
Atp Supply

The dynamic computer model of oxidative phosphorylation developed previously and successfully tested for large-scale changes in fluxes and metabolite concentrations was used to study the question of how the rate of ATP production by oxidative phosphorylation is adjusted to meet the energy demand during muscle contraction, which causes a great increase in ATP consumption in relation to the resting state. The changes in the respiration rate and ATP/ADP ratio after the onset of maximal work measured experimentally were compared with simulated changes in the respiration rate and ATP/ADP in several different cases, assuming direct activation of different steps by an external effector. On the basis of the computer simulations performed, it was possible to conclude which enzymes/metabolic blocks should be directly activated to cause the experimentally observable changes in fluxes and metabolite concentrations. The theoretical results obtained suggest that the parallel direct activation of actinomyosin-ATP-ase and oxidative phosphorylation by an external effector (for example calcium ions) is the main mechanism responsible for fitting of ATP production to ATP consumption, while the negative feedback via an increase in ADP concentration (decrease in ATP/ADP), which indirectly activates the ATP supply, plays only a minor role. Additionally, the conclusion is drawn that most of the oxidative phosphorylation steps should be directly activated in order to explain the observed changes in the respiration rate and ATP/ADP ratio (and also in other parameters) during muscle contraction. It is suggested that there should exist a universal external activator/regulatory mechanism which causes a parallel stimulation of different enzymes/processes. A possible nature of such an activator is shortly discussed.

scholarly journals The ATP Synthase Deficiency in Human Diseases

Life ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 325
Author(s):  
Chiara Galber ◽  
Stefania Carissimi ◽  
Alessandra Baracca ◽  
Valentina Giorgio
Keyword(s):  
Oxidative Phosphorylation ◽  
Atp Synthase ◽  
Mitochondrial Protein ◽  
High Energy ◽  
Neurocognitive Disorders ◽  
Human Diseases ◽  
Age Related ◽  
Muscle Tissues ◽  
Mitochondrial Atp Synthase ◽  
Genes Encoding

Human diseases range from gene-associated to gene-non-associated disorders, including age-related diseases, neurodegenerative, neuromuscular, cardiovascular, diabetic diseases, neurocognitive disorders and cancer. Mitochondria participate to the cascades of pathogenic events leading to the onset and progression of these diseases independently of their association to mutations of genes encoding mitochondrial protein. Under physiological conditions, the mitochondrial ATP synthase provides the most energy of the cell via the oxidative phosphorylation. Alterations of oxidative phosphorylation mainly affect the tissues characterized by a high-energy metabolism, such as nervous, cardiac and skeletal muscle tissues. In this review, we focus on human diseases caused by altered expressions of ATP synthase genes of both mitochondrial and nuclear origin. Moreover, we describe the contribution of ATP synthase to the pathophysiological mechanisms of other human diseases such as cardiovascular, neurodegenerative diseases or neurocognitive disorders.

scholarly journals Epilepsy in Mitochondrial Diseases—Current State of Knowledge on Aetiology and Treatment

Children ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 532
Author(s):  
Dorota Wesół-Kucharska ◽  
Dariusz Rokicki ◽  
Aleksandra Jezela-Stanek
Keyword(s):  
Oxidative Phosphorylation ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Disease ◽  
Clinical Picture ◽  
Poor Prognosis ◽  
Treatment Options ◽  
Mitochondrial Diseases ◽  
Energy Deficit ◽  
Atp Production ◽  
Current State

Mitochondrial diseases are a heterogeneous group of diseases resulting from energy deficit and reduced adenosine triphosphate (ATP) production due to impaired oxidative phosphorylation. The manifestation of mitochondrial disease is usually multi-organ. Epilepsy is one of the most common manifestations of diseases resulting from mitochondrial dysfunction, especially in children. The onset of epilepsy is associated with poor prognosis, while its treatment is very challenging, which further adversely affects the course of these disorders. Fortunately, our knowledge of mitochondrial diseases is still growing, which gives hope for patients to improve their condition in the future. The paper presents the pathophysiology, clinical picture and treatment options for epilepsy in patients with mitochondrial disease.

scholarly journals Bedaquiline, an FDA-approved drug, inhibits mitochondrial ATP production and metastasis in vivo, by targeting the gamma subunit (ATP5F1C) of the ATP synthase

2021 ◽  
Author(s):  
Marco Fiorillo ◽  
Cristian Scatena ◽  
Antonio Giuseppe Naccarato ◽  
Federica Sotgia ◽  
Michael P. Lisanti
Keyword(s):  
Cell Migration ◽  
Treatment Failure ◽  
Atp Synthase ◽  
Atp Depletion ◽  
Multi Drug Resistance ◽  
Gamma Subunit ◽  
Primary Tumors ◽  
Atp Production ◽  
Mitochondrial Atp Synthase

AbstractHere, we provide evidence that high ATP production by the mitochondrial ATP-synthase is a new therapeutic target for anticancer therapy, especially for preventing tumor progression. More specifically, we isolated a subpopulation of ATP-high cancer cells which are phenotypically aggressive and demonstrate increases in proliferation, stemness, anchorage-independence, cell migration, invasion and multi-drug resistance, as well as high antioxidant capacity. Clinically, these findings have important implications for understanding treatment failure and cancer cell dormancy. Using bioinformatic analysis of patient samples, we defined a mitochondrial-related gene signature for metastasis, which features the gamma-subunit of the mitochondrial ATP-synthase (ATP5F1C). The relationship between ATP5F1C protein expression and metastasis was indeed confirmed by immunohistochemistry. Next, we used MDA-MB-231 cells as a model system to functionally validate these findings. Importantly, ATP-high MDA-MB-231 cells showed a nearly fivefold increase in metastatic capacity in vivo. Consistent with these observations, ATP-high cells overexpressed (i) components of mitochondrial complexes I–V, including ATP5F1C, and (ii) markers associated with circulating tumor cells (CTCs) and metastasis, such as EpCAM and VCAM1. Knockdown of ATP5F1C expression significantly reduced ATP-production, anchorage-independent growth, and cell migration, as predicted. Similarly, therapeutic administration of the FDA-approved drug, Bedaquiline, downregulated ATP5F1C expression in vitro and prevented spontaneous metastasis in vivo. In contrast, Bedaquiline had no effect on the growth of non-tumorigenic mammary epithelial cells (MCF10A) or primary tumors in vivo. Taken together, our results suggest that mitochondrial ATP depletion is a new therapeutic strategy for metastasis prophylaxis, to avoid treatment failure. In summary, we conclude that mitochondrial ATP5F1C is a promising new biomarker and molecular target for future drug development, for the prevention of metastatic disease progression.

Dual Mutations Reveal Interactions Between Components of Oxidative Phosphorylation in Kluyveromyces lactis

Genetics ◽  
2001 ◽  
Vol 159 (3) ◽  
pp. 929-938
Author(s):  
G D Clark-Walker ◽  
X J Chen
Keyword(s):  
Electron Transport ◽  
Oxidative Phosphorylation ◽  
Atp Synthase ◽  
Kluyveromyces Lactis ◽  
Mitochondrial Protein ◽  
Proton Pumping ◽  
Nuclear Genes ◽  
Suppressor Activity ◽  
Inner Membrane ◽  
Atp Production

Abstract Loss of mtDNA or mitochondrial protein synthesis cannot be tolerated by wild-type Kluyveromyces lactis. The mitochondrial function responsible for ρ0-lethality has been identified by disruption of nuclear genes encoding electron transport and F0-ATP synthase components of oxidative phosphorylation. Sporulation of diploid strains heterozygous for disruptions in genes for the two components of oxidative phosphorylation results in the formation of nonviable spores inferred to contain both disruptions. Lethality of spores is thought to result from absence of a transmembrane potential, ΔΨ, across the mitochondrial inner membrane due to lack of proton pumping by the electron transport chain or reversal of F1F0-ATP synthase. Synergistic lethality, caused by disruption of nuclear genes, or ρ0-lethality can be suppressed by the atp2.1 mutation in the β-subunit of F1-ATPase. Suppression is viewed as occurring by an increased hydrolysis of ATP by mutant F1, allowing sufficient electrogenic exchange by the translocase of ADP in the matrix for ATP in the cytosol to maintain ΔΨ. In addition, lethality of haploid strains with a disruption of AAC encoding the ADP/ATP translocase can be suppressed by atp2.1. In this case suppression is considered to occur by mutant F1 acting in the forward direction to partially uncouple ATP production, thereby stimulating respiration and relieving detrimental hyperpolarization of the inner membrane. Participation of the ADP/ATP translocase in suppression of ρ0-lethality is supported by the observation that disruption of AAC abolishes suppressor activity of atp2.1.

Abstract 126: Peroxisomal Proliferator Activated Receptor Alpha Overexpression in Hypertrophied Cardiomyocytes Restores Mitochondrial Integrity and Function

2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Sagartirtha Sarkar ◽  
Santanu Rana
Keyword(s):  
Energy Demand ◽  
Cardiac Tissue ◽  
Structural Integrity ◽  
Heart Function ◽  
Ros Generation ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Atp Production ◽  
Receptor Alpha ◽  
And Function

Cardiac tissue engineering is an interdisciplinary field that engineers modulation of viable molecular milieu to restore, maintain or improve heart function. Myocardial workload (energy demand) and energy substrate availability (supply) are in continual flux to maintain specialized cellular processes, yet the heart has a limited capacity for substrate storage and utilization during pathophysiological conditions. Damage to heart muscle, acute or chronic, leads to dysregulation of cardiac metabolic processes associated with gradual but progressive decline in mitochondrial respiratory pathways resulting in diminished ATP production. The Peroxisome Proliferator Activated Receptor Alpha ( PPARα ) is known to regulate fatty acid to glucose metabolic balance as well as mitochondrial structural integrity. In this study, a non-canonical pathway of PPARα was analyzed by cardiomyocyte targeted PPARα overexpression during cardiac hypertrophy that showed significant downregulation in p53 acetylation as well as GSK3β activation levels. Targeted PPARα overexpression during hypertrophy resulted in restoration of mitochondrial structure and function along with significantly improved mitochondrial ROS generation and membrane potential. This is the first report of myocyte targeted PPARα overexpression in hypertrophied myocardium that results in an engineered heart with significantly improved function with increased muscle mitochondrial endurance and reduced mitochondrial apoptotic load, thus conferring a greater resistance to pathological stimuli within cardiac microenvironment.

scholarly journals EFFECTS OF CORTISOL ON CULTURED RAT HEART CELLS

1973 ◽  
Vol 57 (1) ◽  
pp. 109-116 ◽  
Author(s):  
J. V. Anastasia ◽  
R. L. McCarl
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Fatty Acid Oxidation ◽  
Growth Medium ◽  
Rat Heart ◽  
Acid Oxidation ◽  
Heart Cells ◽  
Atp Production ◽  
Rat Heart Cells

This paper reports the determination of the ability of rat heart cells in culture to release [14C]palmitate from its triglyceride and to oxidize this fatty acid and free [14C]palmitate to 14CO2 when the cells are actively beating and when they stop beating after aging in culture. In addition, the levels of glucose, glycogen, and ATP were determined to relate the concentration of these metabolites with beating and with cessation of beating. When young rat heart cells in culture are actively beating, they oxidize free fatty acids at a rate parallel with cellular ATP production. Both fatty acid oxidation and ATP production remain constant while the cells continue to beat. Furthermore, glucose is removed from the growth medium by the cells and stored as glycogen. When cultured cells stop beating, a decrease is seen in their ability to oxidize free fatty acids and to release them from their corresponding triglycerides. Concomitant with decreased fatty acid oxidation is a decrease in cellular levels of ATP until beating ceases. Midway between initiation of cultures and cessation of beating the cells begin to mobilize the stored glycogen. When the growth medium is supplemented with cortisol acetate and given to cultures which have ceased to beat, reinitiation of beating occurs. Furthermore, all decreases previously observed in ATP levels, fatty acid oxidation, and esterase activity are restored.

scholarly journals Superoxide Anion Production and Bioenergetic Profile in Young and Elderly Human Primary Myoblasts

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Mariangela Marrone ◽  
Rita Maria Laura La Rovere ◽  
Simone Guarnieri ◽  
Ester Sara Di Filippo ◽  
Giovanni Monaco ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Oxidative Phosphorylation ◽  
Energy Demand ◽  
The Elderly ◽  
Compensatory Mechanisms ◽  
Superoxide Anion Production ◽  
Age Related ◽  
Primary Myoblasts ◽  
Production Variability ◽  
And Function

Sarcopenia is the age-related loss of skeletal muscle mass, strength, and function. It is associated with regenerative difficulties by satellite cells, adult muscle stem cells, and alteration of oxidative management, mainly the increase in superoxide anions (O2•−). We aimed to investigate the relation between regenerative deficit in elderly and increase in O2•− production along with mitochondrial alterations. Myoblasts and myotubes from skeletal muscle of young and elderly healthy subjects (27.8 ± 6 and 72.4 ± 6.5 years old) were measured: (1) superoxide dismutase activity and protein content, (2) mitochondrial O2•− production levels, (3) O2•− production variability, and (4) mitochondrial bioenergetic profile. Compared to young myoblasts, elderly myoblasts displayed decreased SOD2 protein expression, elevated mitochondrial O2•− baseline levels, and decreased oxidative phosphorylation and glycolysis. Additionally, elderly versus young myotubes showed elevated mitochondrial O2•− levels when stressed with N-acetyl cysteine or high glucose and higher glycolysis despite showing comparable oxidative phosphorylation levels. Altogether, the elderly may have less metabolic plasticity due to the impaired mitochondrial function caused by O2•−. However, the increased energy demand related to the differentiation process appears to activate compensatory mechanisms for the partial mitochondrial dysfunction.

scholarly journals CARDIOKIN1: Computational Assessment of Myocardial Metabolic Capability in Healthy Controls and Patients With Valve Diseases

Circulation ◽  
2021 ◽  
Author(s):  
Nikolaus Berndt ◽  
Johannes Eckstein ◽  
Iwona Wallach ◽  
Sarah Nordmeyer ◽  
Marcus Kelm ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Energy Demand ◽  
Heart Diseases ◽  
Cardiac Metabolism ◽  
Production Reserve ◽  
Energy Status ◽  
Tissue Samples ◽  
Atp Production ◽  
Mechanic Energy

Background: Many heart diseases can develop a reduced pumping capacity of the heart muscle. A mismatch between ATP demand and ATP production of cardiomyocytes is one of the possible causes. Assessment of the relation between the myocardial ATP production (MV ATP ) and cardiac workload is important for better understanding disease development and choice of nutritional or pharmacological treatment strategies. As there is currently no method for the measurement of MV ATP in vivo , the use of physiology-based metabolic models in conjunction with protein abundance data is an attractive approach. Methods: We developed a comprehensive kinetic model of the cardiac energy metabolism (CARDIOKIN1), which recapitulates numerous experimental findings on cardiac metabolism obtained with isolated cardiomyocytes, perfused animal hearts and in vivo studies with humans. We used the model to assess the energy status of the left ventricle (LV) of healthy subjects and patients with aortic stenosis (AS) and mitral valve insufficiency (MI). Maximal enzyme activities were individually scaled by means of protein abundances in LV tissue samples. The energy status of the LV was quantified by the ATP consumption at rest (MV ATP (rest)), at maximal workload (MV ATP (max)), and by the myocardial ATP production reserve (MAPR) representing the span between MV ATP (rest) and MV ATP (max). Results: Compared with controls, in both groups of patients, MV ATP (rest) was increased and MV ATP (max) was decreased resulting in a decreased MAPR, although all patients had preserved ejection fraction. Notably, the variance of the energetic status was high ranging from decreased to normal values. In both patient groups, the energetic status was tightly associated with mechanic energy demand. Moreover, a decrease of MV ATP (max) was associated with a decrease of the cardiac output indicating that cardiac functionality and energetic performance of the ventricle are closely coupled. Conclusions: Our analysis suggests that the ATP producing capacity of the LV of patients with valvular dysfunction is generally diminished and correlates positively with mechanic energy demand and cardiac output. However, large differences exist in the energetic state of the myocardium even in patients with similar clinical or image-based markers of hypertrophy and pump function.

scholarly journals Gene by environmental interactions affecting oxidative phosphorylation and thermal sensitivity

2016 ◽  
Vol 311 (1) ◽  
pp. R157-R165 ◽  
Author(s):  
Tara Z. Baris ◽  
Pierre U. Blier ◽  
Nicolas Pichaud ◽  
Douglas L. Crawford ◽  
Marjorie F. Oleksiak
Keyword(s):  
Oxidative Phosphorylation ◽  
Complex I ◽  
Thermal Sensitivity ◽  
Single Species ◽  
Mitochondrial Haplotype ◽  
Acclimation Temperature ◽  
Atp Production ◽  
Acute Response ◽  
Relative Contribution ◽  
Mitochondrial Genotype

The oxidative phosphorylation (OxPhos) pathway is responsible for most aerobic ATP production and is the only metabolic pathway with proteins encoded by both nuclear and mitochondrial genomes. In studies examining mitonuclear interactions among distant populations within a species or across species, the interactions between these two genomes can affect metabolism, growth, and fitness, depending on the environment. However, there is little data on whether these interactions impact natural populations within a single species. In an admixed Fundulus heteroclitus population with northern and southern mitochondrial haplotypes, there are significant differences in allele frequencies associated with mitochondrial haplotype. In this study, we investigate how mitochondrial haplotype and any associated nuclear differences affect six OxPhos parameters within a population. The data demonstrate significant OxPhos functional differences between the two mitochondrial genotypes. These differences are most apparent when individuals are acclimated to high temperatures with the southern mitochondrial genotype having a large acute response and the northern mitochondrial genotype having little, if any acute response. Furthermore, acute temperature effects and the relative contribution of Complex I and II depend on acclimation temperature: when individuals are acclimated to 12°C, the relative contribution of Complex I increases with higher acute temperatures, whereas at 28°C acclimation, the relative contribution of Complex I is unaffected by acute temperature change. These data demonstrate a complex gene by environmental interaction affecting the OxPhos pathway.

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