The Role of Dietary Saturated Fat in Associations between Exposure to Ambient Fine Particulate Matter and Mitochondrial Respiratory Functions in Circulating Platelets

Abstract Objectives Exposure to ambient fine particulate matter (PM2.5) is associated with platelet activation and increased mitochondrial respiration. The impact of dietary saturated fat on the circulating platelets is not understood. This project aimed to determine whether dietary saturated fatty acids moderate mitochondrial respiratory function in circulating platelets after short-term exposure to PM2.5. Methods Platelets were isolated from 22 healthy male volunteers (mean age ± SD, 37 ± 8.2) in a panel study and measured for mitochondrial oxygen consumption rates using an extracellular flux analyzer. Intakes of saturated fat were determined from 24 hr dietary recalls the day before the assay. Daily ambient PM2.5 concentrations during the study period were obtained from ambient air quality monitoring stations. Data were fitted with a moderation model, where the level of ambient PM2.5 was the independent variable, saturated fat intake was the moderator, and mitochondrial respiratory functions in circulating platelets were the dependent variables. Results After controlling for age, dietary consumption of saturated fat moderated the mitochondrial oxygen consumption rates of non-mitochondrial respiration, basal respiration, maximum respiration, ATP production, and spare respiratory capacity after exposure to ambient PM2.5 with 2 days lag. Specifically, the negative associations between the above mentioned mitochondrial respiratory measurements and PM2.5 levels reached statistical significance (95% Confident Intervals did not include 0) in subjects with a high intake of total saturated fat. Further, results for individual saturated fatty acid showed similar patterns, specifically that negative association between mitochondrial oxygen consumption rates of non-mitochondrial respiration, basal respiration and ATP production and levels of exposed PM2.5 was moderated by intakes of short-chain (C4:0), medium-chain (C6:0, C8:0, C10:0, C12:0), long-chain (C14:0, C16:0) saturated fatty acids. Conclusions Taken together, these preliminary findings suggest that consumption of saturated fat moderates platelet mitochondrial respiration after exposure to PM2.5. THIS ABSTRACT OF A PROPOSED PRESENTATION DOES NOT NECESSARILY REFLECT EPA POLICY. Funding Sources This project was supported by the U.S. EPA Intramural Research Program.

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Mechanical Ventilation Preserves Diaphragm Mitochondrial Function in a Rat Sepsis Model

10.21203/rs.3.rs-94896/v1 ◽

2020 ◽

Author(s):

Pierre Eyenga ◽

Damien Roussel ◽

Benjamin Rey ◽

Patrice Ndille ◽

Loic Teulier ◽

...

Keyword(s):

Mechanical Ventilation ◽

Oxygen Consumption ◽

Cytochrome C ◽

Cytochrome C Oxidase ◽

Oxidase Activity ◽

Ros Generation ◽

Mitochondrial Oxygen Consumption ◽

Atp Production ◽

Mitochondrial Ros ◽

Mda Content

Abstract Background: To describe the effect of mechanical ventilation on diaphragm mitochondrial oxygen consumption, ATP production, reactive oxygen species (ROS) generation, and cytochrome-c oxidase activity and content, and their relationship to diaphragm strength in an experimental model of sepsis.Methods: A cecal ligation and puncture (CLP) protocol was performed in 12 rats while 12 controls underwent sham-operation. Half of the rats in each group were paralyzed and mechanically ventilated. We performed blood gas analysis and lactic acid assays 6 hours after surgery. Afterwards, we measured diaphragm strength and mitochondrial oxygen consumption, ATP and ROS generation, and cytochrome-c oxidase activity. We also measured malondialdehyde (MDA) content as an index of lipid peroxidation, and mRNA expression of the pro-inflammatory interleukin-1β (IL-1β) in diaphragms.Results: CLP rats showed severe hypotension, metabolic acidosis, and upregulation of diaphragm IL-1β mRNA expression. Compared to sham controls, spontaneously breathing CLP rats showed lower diaphragm force and increased susceptibility to fatigue, along with depressed mitochondrial oxygen consumption and ATP production and cytochrome-c oxidase activity. These rats also showed increased mitochondrial ROS generation and MDA content. Mechanical ventilation markedly restored mitochondrial oxygen consumption and ATP production in CLP rats; lowered mitochondrial ROS production by the complex 3; and preserved cytochrome-c oxidase activity.Conclusion: In an experimental model of sepsis, early initiation of mechanical ventilation restores diaphragm mitochondrial function.

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Chronic Hypoxia Enhances β-Oxidation-Dependent Electron Transport via Electron Transferring Flavoproteins

Cells ◽

10.3390/cells8020172 ◽

2019 ◽

Vol 8 (2) ◽

pp. 172 ◽

Cited By ~ 2

Author(s):

Dominik C. Fuhrmann ◽

Catherine Olesch ◽

Nina Kurrle ◽

Frank Schnütgen ◽

Sven Zukunft ◽

...

Keyword(s):

Oxygen Consumption ◽

Fatty Acid ◽

Electron Transport ◽

Mitochondrial Respiration ◽

Chronic Hypoxia ◽

Acute Hypoxia ◽

Acid Synthesis ◽

Acid Oxidation ◽

Fatty Acid Production ◽

Consumption Rates

Hypoxia poses a stress to cells and decreases mitochondrial respiration, in part by electron transport chain (ETC) complex reorganization. While metabolism under acute hypoxia is well characterized, alterations under chronic hypoxia largely remain unexplored. We followed oxygen consumption rates in THP-1 monocytes during acute (16 h) and chronic (72 h) hypoxia, compared to normoxia, to analyze the electron flows associated with glycolysis, glutamine, and fatty acid oxidation. Oxygen consumption under acute hypoxia predominantly demanded pyruvate, while under chronic hypoxia, fatty acid- and glutamine-oxidation dominated. Chronic hypoxia also elevated electron-transferring flavoproteins (ETF), and the knockdown of ETF–ubiquinone oxidoreductase lowered mitochondrial respiration under chronic hypoxia. Metabolomics revealed an increase in citrate under chronic hypoxia, which implied glutamine processing to α-ketoglutarate and citrate. Expression regulation of enzymes involved in this metabolic shunting corroborated this assumption. Moreover, the expression of acetyl-CoA carboxylase 1 increased, thus pointing to fatty acid synthesis under chronic hypoxia. Cells lacking complex I, which experienced a markedly impaired respiration under normoxia, also shifted their metabolism to fatty acid-dependent synthesis and usage. Taken together, we provide evidence that chronic hypoxia fuels the ETC via ETFs, increasing fatty acid production and consumption via the glutamine-citrate-fatty acid axis.

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Dynamics of enhanced mitochondrial respiration in female compared with male rat cerebral arteries

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00231.2015 ◽

2015 ◽

Vol 309 (9) ◽

pp. H1490-H1500 ◽

Cited By ~ 17

Author(s):

Ibolya Rutkai ◽

Somhrita Dutta ◽

Prasad V. Katakam ◽

David W. Busija

Keyword(s):

Mitochondrial Respiration ◽

Ex Vivo ◽

Cerebral Arteries ◽

Anion Channel ◽

Basal Respiration ◽

Male Rat ◽

Sprague Dawley ◽

Voltage Dependent Anion Channel ◽

Male And Female ◽

Atp Production

Mitochondrial respiration has never been directly examined in intact cerebral arteries. We tested the hypothesis that mitochondrial energetics of large cerebral arteries ex vivo are sex dependent. The Seahorse XFe24 analyzer was used to examine mitochondrial respiration in isolated cerebral arteries from adult male and female Sprague-Dawley rats. We examined the role of nitric oxide (NO) on mitochondrial respiration under basal conditions, using Nω-nitro-l-arginine methyl ester, and following pharmacological challenge using diazoxide (DZ), and also determined levels of mitochondrial and nonmitochondrial proteins using Western blot, and vascular diameter responses to DZ. The components of mitochondrial respiration including basal respiration, ATP production, proton leak, maximal respiration, and spare respiratory capacity were elevated in females compared with males, but increased in both male and female arteries in the presence of the NOS inhibitor. Although acute DZ treatment had little effect on mitochondrial respiration of male arteries, it decreased the respiration in female arteries. Levels of mitochondrial proteins in Complexes I–V and the voltage-dependent anion channel protein were elevated in female compared with male cerebral arteries. The DZ-induced vasodilation was greater in females than in males. Our findings show that substantial sex differences in mitochondrial respiratory dynamics exist in large cerebral arteries and may provide the mechanistic basis for observations that the female cerebral vasculature is more adaptable after injury.

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Mitochondrial respiration in muscle and liver from cold-acclimated hypothyroid rats

Journal of Applied Physiology ◽

10.1152/japplphysiol.00363.2003 ◽

2003 ◽

Vol 95 (4) ◽

pp. 1584-1590 ◽

Cited By ~ 18

Author(s):

Angel A. Zaninovich ◽

Inés Rebagliati ◽

Marcela Raíces ◽

Conrado Ricci ◽

Karl Hagmüller

Keyword(s):

Adipose Tissue ◽

Oxygen Consumption ◽

Brown Adipose Tissue ◽

Cold Acclimation ◽

Cold Exposure ◽

Mitochondrial Respiration ◽

Mitochondrial Oxygen Consumption ◽

Normal Body ◽

Thyroid Ablation ◽

Brown Adipose

The effects of long-term cold exposure on muscle and liver mitochondrial oxygen consumption in hypothyroid and normal rats were examined. Thyroid ablation was performed after 8-wk acclimation to 4°C. Hypothyroid and normal controls remained in the cold for an additional 8 wk. At the end of 16-wk cold exposure, all hypothyroid rats were alive and normothermic and had normal body weight. At ambient temperature (24°C), thyroid ablation induced a 65% fall in muscle mitochondrial oxygen consumption, which was reversed by thyroxine but not by norepinephrine administration. After cold acclimation was reached, suppression of thyroid function reduced muscle mitochondrial respiration by 30%, but the hypothyroid values remained about threefold higher than those in hypothyroid muscle in the warm. Blockade of β- and α1-adrenergic receptors in both hypothyroid and normal rats produced hypothermia in vivo and a fall in muscle, liver, and brown adipose tissue mitochondria respiration in vitro. In normal rats, cold acclimation enhanced muscle respiration by 35%, in liver 18%, and in brown adipose tissue 450% over values in the warm. The results demonstrate that thyroid hormones, in the presence of norepinephrine, are major determinants of thermogenic activity in muscle and liver of cold-acclimated rats. After thyroid ablation, cold-induced nonshivering thermogenesis replaced 3,5,3′-triiodothyronine-induced thermogenesis, and normal body temperature was maintained.

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REDUCED CITRATE SYNTHASE ACTIVITY EFFECT ON OXYGEN CONSUMPTION RATES IN ISOLATED MITOCHONDRIA FROM MICE LIVER AND MUSCLES

Baltic Journal of Sport and Health Sciences ◽

10.33607/bjshs.v2i101.52 ◽

2016 ◽

Vol 2 (101) ◽

pp. 26-30

Author(s):

Andrej Fokin ◽

Rasa Žūkienė ◽

Aivaras Ratkevičius

Keyword(s):

Oxygen Consumption ◽

Mitochondrial Respiration ◽

Skeletal Muscles ◽

Citrate Synthase ◽

Oxygen Electrode ◽

Isolated Mitochondria ◽

Activity Effect ◽

Consumption Rates ◽

Centrifugation Method ◽

Mice Liver

Background. Liver and skeletal muscles play the major role in metabolism. Mitochondria are of particular importance in functioning of these organs. We tested the hypothesis that reduced citrate synthase (CS) activity could induce improved fatty substrate and carbohydrate oxidation in mitochondria extracted from liver and hind limb muscles of mice. Methods. Eight mice each of 12-week-old control C57B6/J (B6) and congenic B6.A-(rs3676616-D10Utsw1)/ Kjn (B6.A) mice were studied. The mitochondria were isolated by differential centrifugation method followed by assessment of mitochondrial respiration and citrate synthase (CS) activity. Mitochondrial respiration was measured as oxygen consumption with Clark-type oxygen electrode by using polarography system. CS enzyme activity was measured spectrophotometrically. Results. The activity of CS was by ~32% lower for mitochondria for B6.A compared to B6 mice (603.9 ± 135.6 U/g and 894.2 ± 193.2 U/g, respectively). Mitochondrial respiration did not differ significantly between the strains. Conclusions. 30% reduction in citrate synthase activity does not impair mitochondrial respiration.

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A Multivariate Metabolomics Method for Estimating Platelet Mitochondrial Oxygen Consumption Rates in Patients with Sepsis

Metabolites ◽

10.3390/metabo10040139 ◽

2020 ◽

Vol 10 (4) ◽

pp. 139

Author(s):

Marc R. McCann ◽

Cora E. McHugh ◽

Maggie Kirby ◽

Theodore S. Jennaro ◽

Alan E. Jones ◽

...

Keyword(s):

Oxygen Consumption ◽

Mitochondrial Function ◽

Regression Models ◽

Consumption Rate ◽

P Value ◽

Linear Regression Models ◽

Mitochondrial Oxygen Consumption ◽

Non Invasive ◽

Consumption Rates ◽

Multiple Linear Regression Models

Background: Sepsis-induced alterations in mitochondrial function contribute to organ dysfunction and mortality. Measuring mitochondrial function in vital organs is neither feasible nor practical, highlighting the need for non-invasive approaches. Mitochondrial function may be reflected in the concentrations of metabolites found in platelets and whole blood (WB) samples. We proposed to use these as alternates to indirectly estimate platelet mitochondrial oxygen consumption rate (mOCR) in sepsis patients. Methods: We determined the relationships between platelet mOCR and metabolites in both platelets and WB, as measured by quantitative 1H-NMR metabolomics. The associations were identified by building multiple linear regression models with stepwise forward-backward variable selection. We considered the models to be significant with an ANOVA test (p-value ≤ 0.05) and a positive predicted-R2. Results: The differences in adjusted-R2 and ANOVA p-values (platelet adj-R2: 0.836 (0.0003), 0.711 (0.0004) vs. WB adj-R2: 0.428 (0.0079)) from the significant models indicate the platelet models were more associated with platelet mOCR. Conclusions: Our data suggest there are groups of metabolites in WB (leucine, acetylcarnitine) and platelets (creatine, ADP, glucose, taurine) that are associated with platelet mOCR. Thus, WB and platelet metabolites could be used to estimate platelet mOCR.

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Effect of hyperthermia and acidosis on equine skeletal muscle mitochondrial oxygen consumption

Comparative Exercise Physiology ◽

10.3920/cep200041 ◽

2020 ◽

pp. 1-10

Author(s):

M.S. Davis ◽

M.R. Fulton ◽

A. Popken

Keyword(s):

Skeletal Muscle ◽

Oxygen Consumption ◽

Oxidative Phosphorylation ◽

Muscle Fatigue ◽

Mitochondrial Function ◽

Mitochondrial Respiration ◽

Complex I ◽

Mitochondrial Oxygen Consumption ◽

Biochemical Basis ◽

Complex Ii

The skeletal muscle of exercising horses develops pronounced hyperthermia and acidosis during strenuous or prolonged exercise, with very high tissue temperature and low pH associated with muscle fatigue or damage. The purpose of this study was to evaluate the individual effects of physiologically relevant hyperthermia and acidosis on equine skeletal muscle mitochondrial function, using ex vivo measurement of oxygen consumption to assess the function of different mitochondrial elements. Fresh triceps muscle biopsies from 6 healthy unfit Thoroughbred geldings were permeabilised to permit diffusion of small molecular weight substrates through the sarcolemma and analysed in a high resolution respirometer at 38, 40, 42, and 44 °C, and pH=7.1, 6.5, and 6.1. Oxygen consumption was measured under conditions of non-phosphorylating (leak) respiration and phosphorylating respiration through Complex I and Complex II. Data were analysed using a one-way repeated measures ANOVA and data are expressed as mean ± standard deviation. Leak respiration was ~3-fold higher at 44 °C compared to 38 °C regardless of electron source (Complex I: 22.88±3.05 vs 8.08±1.92 pmol O2/mg/s), P=0.002; Complex II: 79.14±23.72 vs 21.43±11.08 pmol O2/mg/s, P=0.022), resulting in a decrease in efficiency of oxidative phosphorylation. Acidosis had minimal effect on mitochondrial respiration at pH=6.5, but pH=6.1 resulted in a 50% decrease in mitochondrial oxygen consumption. These results suggest that skeletal muscle hyperthermia decreases the efficiency of oxidative phosphorylation through increased leak respiration, thus providing a specific biochemical basis for hyperthermia-induced muscle fatigue. The effect of myocellular acidosis on mitochondrial respiration was minimal under typical levels of acidosis, but atypically severe acidosis can lead to impairment of mitochondrial function.

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Curcumae Radix Extract Reduces Beta-Amyloid (Αβ) and Tau Protein Through Increased Mitochondrial Respiration

10.21203/rs.3.rs-785607/v1 ◽

2021 ◽

Author(s):

Seong lae Jo ◽

Hyun Yang ◽

Jun H. Heo ◽

Sang R. Lee ◽

Hye Won Lee ◽

...

Keyword(s):

Brain Tumor ◽

Energy Metabolism ◽

Neurodegenerative Diseases ◽

Mitochondrial Respiration ◽

Metabolic Flux ◽

Tca Cycle ◽

Basal Respiration ◽

Atp Production ◽

Inflammatory Conditions ◽

Brain Tumor Cells

Abstract Background: Neurodegenerative diseases are increasingly being studied owing to the increasing proportion of the aging population. Several potential compounds have been studied to prevent neurodegenerative diseases, one of which is Curcumae Radix that is known to be beneficial for inflammatory conditions, metabolic syndrome, and various types of pain. However, it is not well studied and its influence on energy metabolism in neurodegenerative diseases is unclear. We focused on the relationship between neurodegenerative diseases and energy metabolism through Curcumae Radix extract in an animal model. Methods: Mice were treated with Curcumae Radix extract for 5 weeks orally 5 times in a week (50 mg/kg body weight). Murine delayed brain tumor (DBT) cells were supplemented with Curcumae Radix extract. We monitored the neurodegenerative makers and metabolic indicators using Western blotting and qRT-PCR and then assessed the cellular glycolysis and mitochondrial respiration through metabolic flux assay.Results: Low expression levels of Alzheimer’s disease-related markers were observed after treatment with Curcumae Radix extract. It was determined through the pAMPK/AMPK ratio that the ATP state was sufficient in the cerebrum and brain tumor cells. With this, an increase in glycolysis would be expected as glucose is the main energy source of the brain. However, glycolysis-related genes and the extracellular acidification rate showed that glycolysis decreased. Despite this, basal respiration and ATP production through mitochondrial respiration and increased TCA cycle and OXPHOS-related genes were observed in the Curcumae Radix group. Conclusions: In neurodegenerative diseases involving mitochondrial dysfunction, Curcumae Radix may act as a metabolic modulator of brain health to treat and prevent these diseases.

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Abstract P340: Histone Methyltransferase Smyd1a Protects Heart From Ischemic Injury By Regulating Mitochondrial Respiration

Circulation Research ◽

10.1161/res.129.suppl_1.p340 ◽

2021 ◽

Vol 129 (Suppl_1) ◽

Author(s):

Marta Szulik ◽

Steven Valdez ◽

Maureen Walsh ◽

Ryan Bia ◽

Kathryn Davis ◽

...

Keyword(s):

Mitochondrial Respiration ◽

Transcriptional Control ◽

Cardiac Tissue ◽

Ischemic Injury ◽

Protective Role ◽

Atp Production ◽

Histone Lysine Methyltransferase ◽

Permanent Occlusion ◽

Consumption Rates

SMYD1a, a myosin-specific histone lysine methyltransferase, plays a major role in regulating disease-induced remodeling in the adult heart. Previously, we demonstrated that the inducible loss of this chromatin-bound enzyme is sufficient to induce cardiac hypertrophy and failure in vivo , which is preceded by downregulation of mitochondrial proteins involved in oxidative phosphorylation (OXPHOS), and reduction of mitochondrial respiration capacity. However, our most recent data in transgenic mice (TG) displaying inducible, cardiomyocyte-specific overexpression of SMYD1a show that these mice are protected from ischemic injury after permanent occlusion (PO) of the LAD manifested by reduced infarct size and cardiac dysfunction compared to littermate controls (WT), suggesting that SMYD1 plays a protective role in the heart and mitigates disease-induced remodeling. Additionally, global proteomic evaluation of cardiac tissue from TG mice showed unique expression of metabolic enzymes, including proteins from the electron transport chain, and our high-resolution mitochondrial respirometry analysis showed that overexpression of SMYD1a leads to increased oxygen consumption rates through Complex I and II. To further asses OXPHOS efficiency in TG mice we subjected them to permanent occlusion of the LAD and evaluated ATP production rates in isolated mitochondria from TG and WT mice, by measuring the molar amount of ATP produced per mole of atomic oxygen consumed (known as ATP:O ratio). Interestingly, we observed a significant increase in ATP:O ratio in TG mice 24h after PO suggesting that they are much more efficient at producing ATP. Finally, we show that the global regulation of mitochondrial respiration in TG mice occurs through transcriptional control of Ppargc1α . Our results confirm that cardiac expression of Ppargc1α was significantly reduced in WT mice (48h after PO) but maintained at basal levels in TG mice, which also corroborated with our ChIP-qPCR data showing SMYD1a binding to the Ppargc1α promoter and regulating its expression. Overall, these results show that SMYD1a can mitigate ischemic injury and adverse remodeling in the adult myocardium, which occurs through Ppargc1α expression and regulation of cardiac energetics and metabolism.

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Energy Metabolism Disturbances in Cell Models of PARK2 CNV Carriers with ADHD

Journal of Clinical Medicine ◽

10.3390/jcm9124092 ◽

2020 ◽

Vol 9 (12) ◽

pp. 4092

Author(s):

Viola Stella Palladino ◽

Andreas G. Chiocchetti ◽

Lukas Frank ◽

Denise Haslinger ◽

Rhiannon McNeill ◽

...

Keyword(s):

Oxygen Consumption ◽

Energy Metabolism ◽

Mitochondrial Dynamics ◽

Control Cell ◽

Copy Number Variants ◽

Atp Production ◽

Cellular Models ◽

Gene And Protein Expression ◽

Consumption Rates ◽

Cellular Phenotypes

The main goal of the present study was the identification of cellular phenotypes in attention-deficit-/hyperactivity disorder (ADHD) patient-derived cellular models from carriers of rare copy number variants (CNVs) in the PARK2 locus that have been previously associated with ADHD. Human-derived fibroblasts (HDF) were cultured and human-induced pluripotent stem cells (hiPSC) were reprogrammed and differentiated into dopaminergic neuronal cells (mDANs). A series of assays in baseline condition and in different stress paradigms (nutrient deprivation, carbonyl cyanide m-chlorophenyl hydrazine (CCCP)) focusing on mitochondrial function and energy metabolism (ATP production, basal oxygen consumption rates, reactive oxygen species (ROS) abundance) were performed and changes in mitochondrial network morphology evaluated. We found changes in PARK2 CNV deletion and duplication carriers with ADHD in PARK2 gene and protein expression, ATP production and basal oxygen consumption rates compared to healthy and ADHD wildtype control cell lines, partly differing between HDF and mDANs and to some extent enhanced in stress paradigms. The generation of ROS was not influenced by the genotype. Our preliminary work suggests an energy impairment in HDF and mDAN cells of PARK2 CNV deletion and duplication carriers with ADHD. The energy impairment could be associated with the role of PARK2 dysregulation in mitochondrial dynamics.

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