Ultrastructural and functional abnormalities of mitochondria in cultivated fibroblasts from α-mannosidosis patients

Abstractα-Mannosidosis is a lysosomal storage disorder caused by α-mannosidase deficiency. Clinical course of the disease ranges from severe infantile to milder juvenile type and includes mental retardation, skeletal deformities, coarse facies, hepatomegaly and hearing loss. The aim of the study was to analyse mitochondrial ultrastructure and function in cultivated fibroblasts from three patients with α-mannosidosis. All patients were homozygous for the c.2248C>T mutation in the MAN2B1 gene encoding lysosomal α-mannosidase. The mutation results in incorrect protein folding and severe decrease of α-mannosidase activity. The misfolded protein is retained by the control system of endoplasmic reticulum (ER). In analysed fibroblasts, we observed dilated ER, higher amount of aberrant mitochondria and reduced mitochondrial mass compared to controls. Respiratory chain complex IV, cytochrome c oxidase (COX), activity and the ratio between COX and citrate synthase (control enzyme) were significantly increased in comparison to controls (P < 0.05). Furthermore, the activity at least from one of other respiratory chain complexes was increased in each studied cell line. Mitochondrial membrane potential as well as reactive oxygen species production were comparable with controls. Based on our results, we hypothesize more profound effect of swelled and damaged mitochondria and ER dilatation on tissues with higher energy demand than fibroblasts have.

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Relationships between the activity of respiratory-chain complexes in pre- (biopsy) or post-slaughter muscle samples and feed efficiency in random-bred Ghezel lambs

Animal Production Science ◽

10.1071/an15184 ◽

2017 ◽

Vol 57 (8) ◽

pp. 1674

Author(s):

M. J. Zamiri ◽

R. Mehrabi ◽

G. R. Kavoosi ◽

H. Rajaei Sharifabadi

Keyword(s):

Respiratory Chain ◽

Feed Intake ◽

Enzyme Activities ◽

Feed Efficiency ◽

Average Daily Gain ◽

Chain Complex ◽

Respiratory Chain Complex ◽

Respiratory Chain Complexes ◽

Chain Complexes ◽

Daily Gain

The present study was conducted to determine the relationship between the activity of mitochondrial respiratory chain complexes in pre- and post-slaughter muscle samples and residual feed intake (RFI) in Ghezel male lambs born as a result of random mating. The study was based on the hypothesis that random-bred lambs with lower feed (or higher) RFI have lower (or higher) respiratory chain-complex activity in muscle samples. Lambs (n = 30) were fed a diet consisting of 70% concentrate and 30% alfalfa hay during a 70-day period. Individual feed intake and average daily gain were recorded to calculate the RFI, feed-conversion ratio (FCR) and adjusted FCR (aFCR). On the basis of these calculations, the lambs were classified into low and high groups for RFI, with FCR and aFCR (n = 22) being one standard deviation above or below the means; this was corroborated by Student’s t-test (P < 0.01). At the end of the experiment, a 10-g biopsy sample was taken from the posterior side of the left femoral biceps. After 24 h, the lambs were slaughtered, and a sample from the posterior side of the right femoral biceps was dissected for determination of mitochondrial protein and respiratory chain-complex activities (Complexes I–V). The RFI was not correlated with the metabolic bodyweight and average daily gain, but was positively correlated (r = 0.56) with the average daily feed intake (P < 0.01); mean daily feed intake in the low-RFI group was 200 g less than that in the high-RFI group. The FCR and aFCR were not significantly (P > 0.05) correlated with average daily feed intake (r = 0.39 and r = 0.36 respectively), but showed a negative correlation (P < 0.01) with average daily gain (r = –0.73 and r = –0.76 respectively). Although very high negative correlations were recorded between the activities of all five respiratory-chain complexes and RFI in muscle samples obtained before (–0.91 to –0.97) and after (–0.92 to –0.97) slaughter, Complexes I and V showed small negative correlations (–0.40) with FCR or aFCR (P < 0.05). Enzyme activities of the respiratory-chain Complexes I, III and V were not significantly different between the pre- and post-slaughter biopsy samples; however, the enzyme activities of respiratory-chain Complexes II and IV were slightly higher in post-slaughter samples (P < 0.01). These results suggested that it may be possible to use the enzymatic activity of respiratory-chain complexes in muscle biopsy samples for screening of lambs for RFI, providing a useful procedure for genetic selection of lambs for this component of feed efficiency. These encouraging results need to be verified in further experiments using other sheep breeds and a larger number of lambs.

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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.

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Effect of inhibitors of mitochondrial respiratory chain complexes on the electromechanical activity in human myocardium

Medicina ◽

10.3390/medicina46100096 ◽

2010 ◽

Vol 46 (10) ◽

pp. 679

Author(s):

Vida Gendvilienė ◽

Irma Martišienė ◽

Danguolė Zablockaitė ◽

Jonas Jurevičius

Keyword(s):

Respiratory Chain ◽

Control Level ◽

Chain Complex ◽

Mitochondrial Respiratory Chain ◽

Human Myocardium ◽

Contraction Force ◽

Respiratory Chain Complexes ◽

Complex Iv ◽

Resting Tension ◽

Chain Complexes

The aim of the study was to investigate the effect of inhibitors of mitochondrial respiratory chain complexes I, III, and IV on the electromechanical activity in human myocardium. Material and methods. The experiments were performed on the human myocardial strips obtained from patients with heart failure (NYHA class III or IV) using a conventional method of registration of myocardial electromechanical activity. Under the perfusion with physiological Tyrode solution (control), contraction force (P) was 0.94±0.12 mN (n=16), relaxation time (t50) was 173.38±5.03 ms (n=15), action potential durations measured at 50% (AP50) and 90% (AP90) repolarization were 248.96±13.38 ms and 398.59±17.93 ms, respectively (n=13). Results. The inhibition of respiratory chain complex I by rotenone (3×10–5 M, the highest concentration applied) decreased contraction force of human myocardium to 48.99%±14.74% (n=3) (P<0.05); AP50, to 81.34%±15.81%; and AP90, to 87.28%±7.25% (n=3) (P>0.05) of control level, while relaxation time and resting tension remained almost unchanged. Antimycin A, an inhibitor of complex III, applied at the highest concentration (3×10–4 M) reduced P to 41.66%±8.8% (n=5) (P<0.001) and marginally increased t50 and decreased the durations of AP. Anoxia (3 mM Na2S2O4) that inhibits the activity of complex IV reduced the contraction force to 9.23%±3.56% (n=6) (P<0.001), AP50 and AP90 to 65.46%±9.95% and 71.07%±8.39% (n=5) (P<0.05) of control level, respectively; furthermore, the resting tension augmented (contracture developed). Conclusions. Our results show that the inhibition of respiratory chain complex IV had the strongest inhibitory effect on the electromechanical activity of failing human myocardium.

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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.

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Regulation of Mitochondrial Respiratory Chain Complex Levels, Organization, and Function by Arginyltransferase 1

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2020.603688 ◽

2020 ◽

Vol 8 ◽

Author(s):

Chunhua Jiang ◽

Balaji T. Moorthy ◽

Devang M. Patel ◽

Akhilesh Kumar ◽

William M. Morgan ◽

...

Keyword(s):

Respiratory Chain ◽

Chain Complex ◽

Mitochondrial Respiratory Chain ◽

Underlying Mechanism ◽

Metabolic Effects ◽

Respiratory Chain Complexes ◽

Mitochondrial Respiratory Chain Complex ◽

Human Disorders ◽

And Function ◽

Alpha Proteobacteria

Arginyltransferase 1 (ATE1) is an evolutionary-conserved eukaryotic protein that localizes to the cytosol and nucleus. It is the only known enzyme in metazoans and fungi that catalyzes posttranslational arginylation. Lack of arginylation has been linked to an array of human disorders, including cancer, by altering the response to stress and the regulation of metabolism and apoptosis. Although mitochondria play relevant roles in these processes in health and disease, a causal relationship between ATE1 activity and mitochondrial biology has yet to be established. Here, we report a phylogenetic analysis that traces the roots of ATE1 to alpha-proteobacteria, the mitochondrion microbial ancestor. We then demonstrate that a small fraction of ATE1 localizes within mitochondria. Furthermore, the absence of ATE1 influences the levels, organization, and function of respiratory chain complexes in mouse cells. Specifically, ATE1-KO mouse embryonic fibroblasts have increased levels of respiratory supercomplexes I+III2+IVn. However, they have decreased mitochondrial respiration owing to severely lowered complex II levels, which leads to accumulation of succinate and downstream metabolic effects. Taken together, our findings establish a novel pathway for mitochondrial function regulation that might explain ATE1-dependent effects in various disease conditions, including cancer and aging, in which metabolic shifts are part of the pathogenic or deleterious underlying mechanism.

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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.

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AML cells have low spare reserve capacity in their respiratory chain that renders them susceptible to oxidative metabolic stress

Blood ◽

10.1182/blood-2014-08-594408 ◽

2015 ◽

Vol 125 (13) ◽

pp. 2120-2130 ◽

Cited By ~ 104

Author(s):

Shrivani Sriskanthadevan ◽

Danny V. Jeyaraju ◽

Timothy E. Chung ◽

Swayam Prabha ◽

Wei Xu ◽

...

Keyword(s):

Respiratory Chain ◽

Metabolic Stress ◽

Chain Complex ◽

Reserve Capacity ◽

Respiratory Chain Complex ◽

Respiratory Chain Complexes ◽

Mitochondrial Mass ◽

Chain Complexes ◽

Key Points ◽

Complex Activities

Key Points AML cells have increased mitochondrial mass, low respiratory chain complex activities, and low spare reserve capacity compared with normal cells. AML cells have heightened sensitivity to inhibitors of the respiratory chain complexes and oxidative stressors.

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Effects of Xingpi Kaiyu Fang on ATP, Na/K-ATPase, and Respiratory Chain Complexes of Hippocampus and Gastrocnemius Muscle in Depressed Rats

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2019/6054926 ◽

2019 ◽

Vol 2019 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Qingjie Yuan ◽

Yang Li ◽

Xiaofei Deng ◽

Huawei Shi ◽

Zhenwu Zhao ◽

...

Keyword(s):

Atpase Activity ◽

Respiratory Chain ◽

Gastrocnemius Muscle ◽

Chain Complex ◽

Respiratory Chain Complex ◽

Atp Content ◽

Mitochondrial Ultrastructure ◽

Respiratory Chain Complexes ◽

Chain Complexes ◽

Ultrastructural Damage

Objective. To clarify the effectiveness and mechanism of the Chinese herbal formula Xingpi Kaiyu Fang (XPKYF) which is composed of American ginseng (Xi-Yang-shen), Radix curcumae (Yu-Jin), Acori tatarinowii rhizoma (Shi-Chang-pu), and Hypericum perforatum (Guan-Ye-lian-qiao) in depressed rats. Methods. The rat model of depression was established by chronic unpredictable mild stress (CUMS) method for 6 weeks. Rats were randomly divided into six groups: control group, CUMS group, CUMS+XPKYF (3.6g/kg/d, 7.2g/kg/d, 14.4g/kg/d) groups, and CUMS+sertraline (4.5mg/kg/d) group. The sucrose preference test and the forced swimming test were performed to assess the rats’ depression behavior. Mitochondrial ultrastructure was observed by transmission electron microscope and adenosine triphosphate (ATP) content, sodium potassium ATPase (Na/K-ATPase) activity, and mitochondrial respiratory chain complexes activities in hippocampus and gastrocnemius muscle were measured at the 14th and 42nd day. Results. Rats subjected to six weeks of CUMS exhibited decreased sucrose preference ratio and prolonged immobility time. CUMS reduced ATP content in hippocampus, decreased Na/K-ATPase activity and respiratory chain complex I, III, and IV activities in hippocampus and gastrocnemius muscle, and damaged mitochondrial ultrastructure of hippocampus and gastrocnemius muscle. XPKYF at 14.4g/kg, the efficacy trend of which was better than the other drug groups, could prevent the stress-induced depressed behavior changes, inhibit the decrease of Na/K-ATPase activity in hippocampus, inhibit the decrease of respiratory chain complex III activities in hippocampus and gastrocnemius muscle, and protect mitochondria from ultrastructural damage. Conclusions. Energy deficiency and damaged mitochondrial ultrastructure were found in hippocampus and gastrocnemius muscle of depressed rats established by CUMS. XPKYF could partly reverse alterations in ATP, Na/K-ATPase, and respiratory chain complexes of hippocampus and gastrocnemius muscle and protect mitochondria from ultrastructural damage. This provides another experimental evidence for the clinical application of XPKYF in the treatment of depression.

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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.

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Composition and stage dynamics of mitochondrial complexes in Plasmodium falciparum

10.1101/2020.10.05.326496 ◽

2020 ◽

Author(s):

Felix Evers ◽

Alfredo Cabrera-Orefice ◽

Dei M. Elurbe ◽

Mariska Kea-te Lindert ◽

Sylwia D. Boltryk ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Respiratory Chain ◽

Metabolic Pathways ◽

Drug Target ◽

Protein Complexes ◽

Chain Complex ◽

Model Organisms ◽

Respiratory Chain Complexes ◽

Eukaryotic Diversity ◽

Chain Complexes

AbstractOur current understanding of mitochondrial functioning is largely restricted to traditional model organisms, which only represent a fraction of eukaryotic diversity. The unusual mitochondrion of malaria parasites is a validated drug target but remains poorly understood. Here, we apply complexome profiling to map the inventory of protein complexes across the pathogenic asexual blood stages and the transmissible gametocyte stages of Plasmodium falciparum. We identify remarkably divergent composition and clade-specific additions of all respiratory chain complexes. Furthermore, we show that respiratory chain complex components and linked metabolic pathways are up to 40-fold more prevalent in gametocytes, while glycolytic enzymes are substantially reduced. Underlining this functional switch, we find that cristae are exclusively present in gametocytes. Leveraging these divergent properties and stage dynamics for drug development presents an attractive opportunity to discover novel classes of antimalarials and increase our repertoire of gametocytocidal drugs.

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