Perinatal maturation of rat kidney mitochondria

In the rat kidney, NaK-ATPase activity increased between days 19 and 20 of gestation (+50%) and between 1 and 24 h after birth (+20%), requiring an increased energy supply. In order to determine whether mitochondrial changes were involved, renal mitochondrial development was investigated from day 19 of gestation to 1 day after birth. Slot-blot analyses of mitochondrial-DNA/nuclear-DNA ratio and determination of citrate synthase activity showed a doubling in the mitochondrial pool between days 19 and 20 of gestation. In isolated mitochondria, oxygen consumption remained unchanged between days 19 and 20 of gestation, and then it was enhanced between days 20 and 21 of gestation (+70%) and between 1 and 24 h after birth (+50%). We also focused on one of the respiratory-chain complexes, ATP synthase, and measured its activity and content during the perinatal period. We demonstrated increases in both activity and content of ATP synthase between days 20 and 21 of gestation and between 1 and 24 h after birth, thus suggesting that changes in ATP synthase activity are ascribed to an increase in the mitochondrial density of ATP synthase complexes. Moreover, the mitochondrial ATP/ADP ratio only increased between 1 and 24 h (+90%), indicating a critical step in the renal respiratory-chain maturation at that time. We therefore conclude that the postnatal enhancement of renal mitochondrial oxidative capacity might depend on protein synthesis de novo and on changes in the adenine nucleotide concentrations.

Download Full-text

Physiological diversity of mitochondrial oxidative phosphorylation

AJP Cell Physiology ◽

10.1152/ajpcell.00195.2006 ◽

2006 ◽

Vol 291 (6) ◽

pp. C1172-C1182 ◽

Cited By ~ 196

Author(s):

G. Benard ◽

B. Faustin ◽

E. Passerieux ◽

A. Galinier ◽

C. Rocher ◽

...

Keyword(s):

Oxidative Phosphorylation ◽

Respiratory Chain ◽

Citrate Synthase ◽

Intrinsic Activity ◽

Mitochondrial Oxidative Phosphorylation ◽

Respiratory Chain Complexes ◽

Mitochondrial Content ◽

Physiological Diversity ◽

Chain Complexes ◽

Functional Features

To investigate the physiological diversity in the regulation and control of mitochondrial oxidative phosphorylation, we determined the composition and functional features of the respiratory chain in muscle, heart, liver, kidney, and brain. First, we observed important variations in mitochondrial content and infrastructure via electron micrographs of the different tissue sections. Analyses of respiratory chain enzyme content by Western blot also showed large differences between tissues, in good correlation with the expression level of mitochondrial transcription factor A and the activity of citrate synthase. On the isolated mitochondria, we observed a conserved molar ratio between the respiratory chain complexes and a variable stoichiometry for coenzyme Q and cytochrome c, with typical values of [1–1.5]:[30–135]:[3]:[9–35]:[6.5–7.5] for complex II:coenzyme Q:complex III:cytochrome c:complex IV in the different tissues. The functional analysis revealed important differences in maximal velocities of respiratory chain complexes, with higher values in heart. However, calculation of the catalytic constants showed that brain contained the more active enzyme complexes. Hence, our study demonstrates that, in tissues, oxidative phosphorylation capacity is highly variable and diverse, as determined by different combinations of 1) the mitochondrial content, 2) the amount of respiratory chain complexes, and 3) their intrinsic activity. In all tissues, there was a large excess of enzyme capacity and intermediate substrate concentration, compared with what is required for state 3 respiration. To conclude, we submitted our data to a principal component analysis that revealed three groups of tissues: muscle and heart, brain, and liver and kidney.

Download Full-text

The F1F0 ATP synthase and mitochondrial respiratory chain complexes are present on the plasma membrane of an osteosarcoma cell line: An immunocytochemical study

Mitochondrion ◽

10.1016/j.mito.2006.10.001 ◽

2006 ◽

Vol 6 (6) ◽

pp. 305-314 ◽

Cited By ~ 29

Author(s):

Sarah K. Yonally ◽

Roderick A. Capaldi

Keyword(s):

Plasma Membrane ◽

Cell Line ◽

Respiratory Chain ◽

Atp Synthase ◽

Mitochondrial Respiratory Chain ◽

Osteosarcoma Cell ◽

Immunocytochemical Study ◽

Respiratory Chain Complexes ◽

Chain Complexes ◽

F1f0 Atp Synthase

Download Full-text

Tracking protons from respiratory chain complexes to ATP synthase c -subunit: The critical role of serine and threonine residues

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2016.11.134 ◽

2017 ◽

Vol 482 (4) ◽

pp. 922-927 ◽

Cited By ~ 1

Author(s):

Isabella Panfoli ◽

Marco Ponassi ◽

Silvia Ravera ◽

Daniela Calzia ◽

Maider Beitia ◽

...

Keyword(s):

Respiratory Chain ◽

Atp Synthase ◽

Critical Role ◽

Respiratory Chain Complexes ◽

Chain Complexes ◽

C Subunit

Download Full-text

Brain energy metabolism is increased by chronic administration of bupropion

Acta Neuropsychiatrica ◽

10.1111/j.1601-5215.2011.00597.x ◽

2012 ◽

Vol 24 (2) ◽

pp. 115-121 ◽

Cited By ~ 3

Author(s):

Gabriela K. Ferreira ◽

Gislaine T. Rezin ◽

Mariane R. Cardoso ◽

Cinara L. Gonçalves ◽

Lislaine S. Borges ◽

...

Keyword(s):

Energy Metabolism ◽

Malate Dehydrogenase ◽

Respiratory Chain ◽

Citrate Synthase ◽

Chronic Administration ◽

Mitochondrial Respiratory Chain ◽

Brain Energy Metabolism ◽

Respiratory Chain Complexes ◽

Chain Complexes ◽

Brain Energy

Objectives: Based on the hypothesis that energy impairment may be involved in the pathophysiology of depression, we evaluated the activities of citrate synthase, malate dehydrogenase, succinate dehydrogenase (SDH), mitochondrial respiratory chain complexes I, II, II-III, IV and creatine kinase (CK) in the brain of rats submitted to chronic administration of bupropion.Methods: Animals received daily administration of bupropion dissolved in saline (10 mg/kg, intraperitoneal) at 1.0 ml/kg body weight. The rats received injections once a day for 14 days; control rats received an equivalent volume of saline. Twelve hours after the last administration, the rats were killed by decapitation and brain was rapidly removed and kept on an ice plate. The activities of the enzymes were measured in different brain areas.Results: We observed that the activities of citrate synthase and malate dehydrogenase, mithocondrial respiratory chain complexes I, II-III and IV and CK were not altered after chronic administration of bupropion. However, SDH activity was increased in the prefrontal cortex and cerebellum. In the hippocampus, cerebellum and striatum the activity of complex II was increased after chronic administration of bupropion.Conclusions: Our results demonstrated that bupropion increased some enzymes of brain energy metabolism. These findings are in accordance with other studies which showed that some antidepressants may improve energy metabolism. The present results reinforce the hypothesis that antidepressants modulate brain energy metabolism.

Download Full-text

Activity of Mitochondrial Respiratory Chain Enzymes after Transient Focal Ischemia in the Rat

Journal of Cerebral Blood Flow & Metabolism ◽

10.1097/00004647-199711000-00005 ◽

1997 ◽

Vol 17 (11) ◽

pp. 1166-1169 ◽

Cited By ~ 34

Author(s):

Laura Canevari ◽

Satoshi Kuroda ◽

Timothy E. Bates ◽

John B. Clark ◽

Bo K. Siesjö

Keyword(s):

Respiratory Chain ◽

Citrate Synthase ◽

Mitochondrial Respiratory Chain ◽

Artery Occlusion ◽

Respiratory Chain Complexes ◽

Secondary Damage ◽

Chain Complexes ◽

Postischemic Recirculation ◽

Transient Focal Ischemia ◽

Mitochondrial Respiratory

Previous results demonstrated that after 2-hour middle cerebral artery occlusion (MCAO) in the rat, 1- to 2-hour recirculation temporarily restored the bioenergetic state and mitochondrial function, but secondary deterioration took place after 4 hours. The authors measured the activity of mitochondrial respiratory chain complexes, citrate synthase, and glutamate dehydrogenase as possible targets of secondary damage. Focal and penumbral tissues were sampled in the control condition, after 2 hours of MCAO, and after 1, 2, or 4 hours of postischemic recirculation; two groups were treated with α-phenyl-N- tert-butyl-nitrone (PBN). Complex IV activity transiently decreased after MCAO, but after recirculation all measured activities returned to control values.

Download Full-text

Cytotoxicity of mitochondria-targeted resveratrol derivatives: Interactions with respiratory chain complexes and ATP synthase

Biochimica et Biophysica Acta (BBA) - Bioenergetics ◽

10.1016/j.bbabio.2014.06.010 ◽

2014 ◽

Vol 1837 (10) ◽

pp. 1781-1789 ◽

Cited By ~ 34

Author(s):

Nicola Sassi ◽

Andrea Mattarei ◽

Michele Azzolini ◽

Ildiko' Szabo' ◽

Cristina Paradisi ◽

...

Keyword(s):

Respiratory Chain ◽

Atp Synthase ◽

Respiratory Chain Complexes ◽

Chain Complexes ◽

Resveratrol Derivatives

Download Full-text

Mitotane alters mitochondrial respiratory chain activity by inducing cytochrome c oxidase defect in human adrenocortical cells

Endocrine Related Cancer ◽

10.1530/erc-12-0368 ◽

2013 ◽

Vol 20 (3) ◽

pp. 371-381 ◽

Cited By ~ 50

Author(s):

Ségolène Hescot ◽

Abdelhamid Slama ◽

Anne Lombès ◽

Angelo Paci ◽

Hervé Remy ◽

...

Keyword(s):

Respiratory Chain ◽

Nuclear Dna ◽

Maximum Velocity ◽

Chain Complex ◽

Mitochondrial Respiratory Chain ◽

Dependent Manner ◽

Respiratory Chain Complexes ◽

Adrenocortical Cells ◽

Native Page ◽

Respiratory Chain Defect

Mitotane, 1,1-dichloro-2-(o-chlorophenyl)-2-(p-chlorophenyl)ethane is the most effective medical therapy for adrenocortical carcinoma, but its molecular mechanism of action remains poorly understood. Although mitotane is known to have mitochondrial (mt) effects, a direct link to mt dysfunction has never been established. We examined the functional consequences of mitotane exposure on proliferation, steroidogenesis, and mt respiratory chain, biogenesis and morphology, in two human adrenocortical cell lines, the steroid-secreting H295R line and the non-secreting SW13 line. Mitotane inhibited cell proliferation in a dose- and a time-dependent manner. At the concentration of 50 μM (14 mg/l), which corresponds to the threshold for therapeutic efficacy, mitotane drastically reduced cortisol and 17-hydroxyprogesterone secretions by 70%. This was accompanied by significant decreases in the expression of genes encoding mt proteins involved in steroidogenesis (STAR, CYP11B1, and CYP11B2). In both H295R and SW13 cells, 50 μM mitotane significantly inhibited (50%) the maximum velocity of the activity of the respiratory chain complex IV (cytochrome c oxidase (COX)). This effect was associated with a drastic reduction in steady-state levels of the whole COX complex as revealed by blue native PAGE and reduced mRNA expression of both mtDNA-encoded COX2 (MT-CO2) and nuclear DNA-encoded COX4 (COX4I1) subunits. In contrast, the activity and expression of respiratory chain complexes II and III were unaffected by mitotane treatment. Lastly, mitotane exposure enhanced mt biogenesis (increase in mtDNA content and PGC1α (PPARGC1A) expression) and triggered fragmentation of the mt network. Altogether, our results provide first evidence that mitotane induced a mt respiratory chain defect in human adrenocortical cells.

Download Full-text

Le encefalomiopatie mitocondriali

Rivista di Neuroradiologia ◽

10.1177/197140099600900623 ◽

1996 ◽

Vol 9 (6) ◽

pp. 775-780 ◽

Cited By ~ 1

Author(s):

E. Ciceri ◽

I. Moroni ◽

G. Uziel ◽

M. Savoiardo

Keyword(s):

Mitochondrial Dna ◽

Respiratory Chain ◽

Mitochondrial Disease ◽

Nuclear Dna ◽

Molecular Genetic ◽

Neuromuscular Diseases ◽

Disease Classification ◽

Respiratory Chain Complexes ◽

Enzyme Defect ◽

Mitochondrial Encephalomyopathies

The mitochondrial encephalomyopathies are relatively rare neuromuscular diseases clinically characterised by myopathy and encephalopathy caused by structurally or functionally impaired mitochondria. The biochemical hallmark of this group of disorders is impaired mitochondrial energy production: Kreb's cycle, respiratory chain, oxidative phosphorylation and beta-oxidation of fatty acids. The presence of lactic acidosis and ragged red fibres, i.e. subsarcolemmal accumulations of abnormally sized mitochondria are highly indicative findings for mitochondrial disease. Classification and diagnostic criteria are based on biochemical findings with a search for specific enzyme deficit and molecular genetic information. Molecular genetic studies aim to identify the mitochondrial DNA changes responsible for the enzyme defect. Ragged red fibres are not essential for diagnosis as they are not present in some diseases. In rare cases, mitochondrial diseases are caused by nuclear DNA defects or, more commonly a mitochondrial DNA deficit. Diagnosis may prove difficult given the pathogenetic complexity and clinical and phenotypical variability of these conditions. Despite indirect symptoms of mitochondrial disease, the enzyme defect and genetic alteration cannot be identified in some cases. The mitochondrial encephalopathies can be classified according to the metabolic pathways involved into impaired transport ot uptake of energy, impaired Kreb's cycle or respiratory chain complexes or complex defects due to mitochondrial DNA changes.

Download Full-text

Skeletal muscle metabolism in sea-acclimatized king penguins. II. Improved efficiency of mitochondrial bioenergetics

Journal of Experimental Biology ◽

10.1242/jeb.233684 ◽

2020 ◽

Vol 223 (21) ◽

pp. jeb233684

Author(s):

Damien Roussel ◽

Vincent Marmillot ◽

Pierre-Axel Monternier ◽

Aurore Bourguignon ◽

Gaëlle Toullec ◽

...

Keyword(s):

Skeletal Muscle ◽

Respiratory Chain ◽

Citrate Synthase ◽

Coupling Efficiency ◽

Chain Complex ◽

Atp Synthesis ◽

Respiratory Chain Complexes ◽

Marine Habitat ◽

Muscle Mitochondria

ABSTRACTAt fledging, juvenile king penguins (Aptenodytes patagonicus) must overcome the tremendous energetic constraints imposed by their marine habitat, including during sustained extensive swimming activity and deep dives in cold seawater. Both endurance swimming and skeletal muscle thermogenesis require high mitochondrial respiratory capacity while the submerged part of dive cycles repeatedly and greatly reduces oxygen availability, imposing a need for solutions to conserve oxygen. The aim of the present study was to determine in vitro whether skeletal muscle mitochondria become more ‘thermogenic’ to sustain heat production or more ‘economical’ to conserve oxygen in sea-acclimatized immature penguins (hereafter ‘immatures’) compared with terrestrial juveniles. Rates of mitochondrial oxidative phosphorylation were measured in permeabilized fibers and mitochondria from the pectoralis muscle. Mitochondrial ATP synthesis and coupling efficiency were measured in isolated muscle mitochondria. The mitochondrial activities of respiratory chain complexes and citrate synthase were also assessed. The results showed that respiration, ATP synthesis and respiratory chain complex activities in pectoralis muscles were increased by sea acclimatization. Furthermore, muscle mitochondria were on average 30–45% more energy efficient in sea-acclimatized immatures than in pre-fledging juveniles, depending on the respiratory substrate used (pyruvate, palmitoylcarnitine). Hence sea acclimatization favors the development of economical management of oxygen, decreasing the oxygen needed to produce a given amount of ATP. This mitochondrial phenotype may improve dive performance during the early marine life of king penguins, by extending their aerobic dive limit.

Download Full-text