Sample records for cardiac mitochondrial compromise

  1. Cardiac, Skeletal, and smooth muscle mitochondrial respiration

    DEFF Research Database (Denmark)

    Park, Song-Young; Gifford, Jayson R; Andtbacka, Robert H I


    Unlike cardiac and skeletal muscle, little is known about vascular smooth muscle mitochondrial function. Therefore, this study examined mitochondrial respiratory rates in the smooth muscle of healthy human feed arteries and compared with that of healthy cardiac and skeletal muscle. Cardiac......, skeletal, and smooth muscle was harvested from a total of 22 subjects (53±6 yrs) and mitochondrial respiration assessed in permeabilized fibers. Complex I+II, state 3 respiration, an index of oxidative phosphorylation capacity, fell progressively from cardiac, skeletal, to smooth muscle (54±1; 39±4; 15......±1 pmol•s(-1)•mg (-1), psmooth muscle (222±13; 115±2; 48±2 umol•g(-1)•min(-1), p

  2. Widespread Mitochondrial Depletion via Mitophagy Does Not Compromise Necroptosis

    Directory of Open Access Journals (Sweden)

    Stephen W.G. Tait


    Full Text Available Programmed necrosis (or necroptosis is a form of cell death triggered by the activation of receptor interacting protein kinase-3 (RIPK3. Several reports have implicated mitochondria and mitochondrial reactive oxygen species (ROS generation as effectors of RIPK3-dependent cell death. Here, we directly test this idea by employing a method for the specific removal of mitochondria via mitophagy. Mitochondria-deficient cells were resistant to the mitochondrial pathway of apoptosis, but efficiently died via tumor necrosis factor (TNF-induced, RIPK3-dependent programmed necrosis or as a result of direct oligomerization of RIPK3. Although the ROS scavenger butylated hydroxyanisole (BHA delayed TNF-induced necroptosis, it had no effect on necroptosis induced by RIPK3 oligomerization. Furthermore, although TNF-induced ROS production was dependent on mitochondria, the inhibition of TNF-induced necroptosis by BHA was observed in mitochondria-depleted cells. Our data indicate that mitochondrial ROS production accompanies, but does not cause, RIPK3-dependent necroptotic cell death.

  3. Induction of mitochondrial dysfunction as a strategy for targeting tumour cells in metabolically compromised microenvironments. (United States)

    Zhang, Xiaonan; Fryknäs, Mårten; Hernlund, Emma; Fayad, Walid; De Milito, Angelo; Olofsson, Maria Hägg; Gogvadze, Vladimir; Dang, Long; Påhlman, Sven; Schughart, Leoni A Kunz; Rickardson, Linda; D'Arcy, Padraig; Gullbo, Joachim; Nygren, Peter; Larsson, Rolf; Linder, Stig


    Abnormal vascularization of solid tumours results in the development of microenvironments deprived of oxygen and nutrients that harbour slowly growing and metabolically stressed cells. Such cells display enhanced resistance to standard chemotherapeutic agents and repopulate tumours after therapy. Here we identify the small molecule VLX600 as a drug that is preferentially active against quiescent cells in colon cancer 3-D microtissues. The anticancer activity is associated with reduced mitochondrial respiration, leading to bioenergetic catastrophe and tumour cell death. VLX600 shows enhanced cytotoxic activity under conditions of nutrient starvation. Importantly, VLX600 displays tumour growth inhibition in vivo. Our findings suggest that tumour cells in metabolically compromised microenvironments have a limited ability to respond to decreased mitochondrial function, and suggest a strategy for targeting the quiescent populations of tumour cells for improved cancer treatment.

  4. Rapamycin doses sufficient to extend lifespan do not compromise muscle mitochondrial content or endurance

    DEFF Research Database (Denmark)

    Widlund, Anne Lykkegaard; Vang, Ole; Ye, Lan;


    Rapamycin extends lifespan in mice, but can have a number of undesirable effects that may ultimately limit its utility in humans. The canonical target of rapamycin, and the one thought to account for its effects on lifespan, is the mammalian/mechanistic target of rapamycin, complex 1 (mTORC1). We...... have previously shown that at least some of the detrimental side effects of rapamycin are due to "off target" disruption of mTORC2, suggesting they could be avoided by more specific targeting of mTORC1. However, mTORC1 inhibitionper se can reduce the mRNA expression of mitochondrial genes...... and compromise the function of mitochondria in cultured muscle cells, implying that defects in bioenergetics might be an unavoidable consequence of targeting mTORC1 in vivo. Therefore, we tested whether rapamycin, at the same doses used to extend lifespan, affects mitochondrial function in skeletal muscle. While...

  5. Cardiac nuclear receptors: architects of mitochondrial structure and function. (United States)

    Vega, Rick B; Kelly, Daniel P


    The adult heart is uniquely designed and equipped to provide a continuous supply of energy in the form of ATP to support persistent contractile function. This high-capacity energy transduction system is the result of a remarkable surge in mitochondrial biogenesis and maturation during the fetal-to-adult transition in cardiac development. Substantial evidence indicates that nuclear receptor signaling is integral to dynamic changes in the cardiac mitochondrial phenotype in response to developmental cues, in response to diverse postnatal physiologic conditions, and in disease states such as heart failure. A subset of cardiac-enriched nuclear receptors serve to match mitochondrial fuel preferences and capacity for ATP production with changing energy demands of the heart. In this Review, we describe the role of specific nuclear receptors and their coregulators in the dynamic control of mitochondrial biogenesis and energy metabolism in the normal and diseased heart.

  6. Compromised mitochondrial fatty acid synthesis in transgenic mice results in defective protein lipoylation and energy disequilibrium.

    Directory of Open Access Journals (Sweden)

    Stuart Smith

    Full Text Available A mouse model with compromised mitochondrial fatty acid synthesis has been engineered in order to assess the role of this pathway in mitochondrial function and overall health. Reduction in the expression of mitochondrial malonyl CoA-acyl carrier protein transacylase, a key enzyme in the pathway encoded by the nuclear Mcat gene, was achieved to varying extents in all examined tissues employing tamoxifen-inducible Cre-lox technology. Although affected mice consumed more food than control animals, they failed to gain weight, were less physically active, suffered from loss of white adipose tissue, reduced muscle strength, kyphosis, alopecia, hypothermia and shortened lifespan. The Mcat-deficient phenotype is attributed primarily to reduced synthesis, in several tissues, of the octanoyl precursors required for the posttranslational lipoylation of pyruvate and α-ketoglutarate dehydrogenase complexes, resulting in diminished capacity of the citric acid cycle and disruption of energy metabolism. The presence of an alternative lipoylation pathway that utilizes exogenous free lipoate appears restricted to liver and alone is insufficient for preservation of normal energy metabolism. Thus, de novo synthesis of precursors for the protein lipoylation pathway plays a vital role in maintenance of mitochondrial function and overall vigor.

  7. Diuretics Prevent Thiazolidinedione-Induced Cardiac Hypertrophy without Compromising Insulin-Sensitizing Effects in Mice (United States)

    Chang, Cherng-Shyang; Tsai, Pei-Jane; Sung, Junne-Ming; Chen, Ju-Yi; Ho, Li-Chun; Pandya, Kumar; Maeda, Nobuyo; Tsai, Yau-Sheng


    Much concern has arisen regarding critical adverse effects of thiazolidinediones (TZDs), including rosiglitazone and pioglitazone, on cardiac tissue. Although TZD-induced cardiac hypertrophy (CH) has been attributed to an increase in plasma volume or a change in cardiac nutrient preference, causative roles have not been established. To test the hypothesis that volume expansion directly mediates rosiglitazone-induced CH, mice were fed a high-fat diet with rosiglitazone, and cardiac and metabolic consequences were examined. Rosiglitazone treatment induced volume expansion and CH in wild-type and PPARγ heterozygous knockout (Pparg+/−) mice, but not in mice defective for ligand binding (PpargP465L/+). Cotreatment with the diuretic furosemide in wild-type mice attenuated rosiglitazone-induced CH, hypertrophic gene reprogramming, cardiomyocyte apoptosis, hypertrophy-related signal activation, and left ventricular dysfunction. Similar changes were observed in mice treated with pioglitazone. The diuretics spironolactone and trichlormethiazide, but not amiloride, attenuated rosiglitazone effects on volume expansion and CH. Interestingly, expression of glucose and lipid metabolism genes in the heart was altered by rosiglitazone, but these changes were not attenuated by furosemide cotreatment. Importantly, rosiglitazone-mediated whole-body metabolic improvements were not affected by furosemide cotreatment. We conclude that releasing plasma volume reduces adverse effects of TZD-induced volume expansion and cardiac events without compromising TZD actions in metabolic switch in the heart and whole-body insulin sensitivity. PMID:24287404

  8. Self-inflicted Cardiac Injury with Nail Gun Without Hemodynamic Compromise: A Case Report (United States)

    Ho, Simon; Feranec, Nicholas


    Pneumatically powered nail guns have been used in construction since 1959. Penetrating injuries to the heart with nail guns have a wide range of presentations from asymptomatic to cardiac tamponade and exsanguination. Mortality related to cardiac nail gun injuries is similar to knife injuries, estimated at 25%. Surgical exploration is the treatment of choice. We describe a case of self-inflicted nail gun injury to the chest without hemodynamic compromise in a 51-year-old man. Computed tomography (CT) imaging confirmed nail penetrating the right ventricle, with the tip adjacent to but not violating the abdominal aorta. The patient was successfully treated with thoracotomy and foreign body removal. PMID:28191375

  9. Low T3 State Is Correlated with Cardiac Mitochondrial Impairments after Ischemia Reperfusion Injury: Evidence from a Proteomic Approach

    Directory of Open Access Journals (Sweden)

    Francesca Forini


    Full Text Available Mitochondria are major determinants of cell fate in ischemia/reperfusion injury (IR and common effectors of cardio-protective strategies in cardiac ischemic disease. Thyroid hormone homeostasis critically affects mitochondrial function and energy production. Since a low T3 state (LT3S is frequently observed in the post infarction setting, the study was aimed to investigate the relationship between 72 h post IR T3 levels and both the cardiac function and the mitochondrial proteome in a rat model of IR. The low T3 group exhibits the most compromised cardiac performance along with the worst mitochondrial activity. Accordingly, our results show a different remodeling of the mitochondrial proteome in the presence or absence of a LT3S, with alterations in groups of proteins that play a key role in energy metabolism, quality control and regulation of cell death pathways. Overall, our findings highlight a relationship between LT3S in the early post IR and poor cardiac and mitochondrial outcomes, and suggest a potential implication of thyroid hormone in the cardio-protection and tissue remodeling in ischemic disease.

  10. Role of mitochondrial damage during cardiac apoptosis in septic rats

    Institute of Scientific and Technical Information of China (English)

    LI Li; HU Bang-chuan; CHEN Chang-qin; GONG Shi-jin; YU Yi-hua; DAI Hai-wen; YAN Jing


    Background Myocardial apoptosis is involved in the pathogenesis of sepsis-related myocardial depression.However,the underlying mechanism remains unknown.This study investigated the role of mitochondrial damage and mitochondria-induced oxidative stress during cardiac apoptosis in septic rats.Methods Seventy-two Sprague-Dawley rats were randomly divided into a control group and septic group receiving lipopolysaccharide injection.Heart tissue was removed and changes in cardiac morphology were observed by light microscopy and scanning electron microscopy.In situ apoptosis was examined using terminal transferase-mediated dUTP nick end-labeling assay and nuclear factor-kappa B activation in myocardium by Western blotting to estimate myocardial apoptosis.Appearance of mitochondrial cristae and activation of cytochrome C oxidase were used to evaluate mitochondrial damage.Oxidative stress was assessed by mitochondrial lipid and protein oxidation,and antioxidant defense was assessed by mitochondrial superoxide dismutase and glutathione peroxidase activity.Results Sepsis-induced inflammatory cell infiltration,myocardium degeneration and dropsy were time-dependent.Expanded capillaries were observed in the hearts of infected rats 24 hours post-challenge.Compared with sham-treated rats,the percentage of cell apoptosis increased in a time-dependent manner in hearts from septic rats at 6 hours,12 hours and 24 hours post-injection (P < 0.05).The expression of nuclear factor-kappa B p65 decreased gradually in the cytosol and increased in the nucleus during sepsis,indicating that septic challenge provoked the progressive activation of nuclear factor-kappa B.Mitochondrial cristae and activation of cytochrome C oxidase increased in a time-dependent manner.Both superoxide dismutase and glutathione peroxidase activities decreased,while mitochondrial lipid and protein oxidation increased between 6 and 24 hours after lipopolysaccharide challenge.Conclusions Septic challenge induced

  11. Effects of Caloric Restriction on Cardiac Oxidative Stress and Mitochondrial Bioenergetics: Potential Role of Cardiac Sirtuins

    Directory of Open Access Journals (Sweden)

    Ken Shinmura


    Full Text Available The biology of aging has not been fully clarified, but the free radical theory of aging is one of the strongest aging theories proposed to date. The free radical theory has been expanded to the oxidative stress theory, in which mitochondria play a central role in the development of the aging process because of their critical roles in bioenergetics, oxidant production, and regulation of cell death. A decline in cardiac mitochondrial function associated with the accumulation of oxidative damage might be responsible, at least in part, for the decline in cardiac performance with age. In contrast, lifelong caloric restriction can attenuate functional decline with age, delay the onset of morbidity, and extend lifespan in various species. The effect of caloric restriction appears to be related to a reduction in cellular damage induced by reactive oxygen species. There is increasing evidence that sirtuins play an essential role in the reduction of mitochondrial oxidative stress during caloric restriction. We speculate that cardiac sirtuins attenuate the accumulation of oxidative damage associated with age by modifying specific mitochondrial proteins posttranscriptionally. Therefore, the distinct role of each sirtuin in the heart subjected to caloric restriction should be clarified to translate sirtuin biology into clinical practice.

  12. Mitochondrial bioenergetics and redox state are unaltered in Trypanosoma cruzi isolates with compromised mitochondrial complex I subunit genes. (United States)

    Carranza, Julio César; Kowaltowski, Alicia J; Mendonça, Marco Aurélio G; de Oliveira, Thays C; Gadelha, Fernanda R; Zingales, Bianca


    In trypanosomatids the involvement of mitochondrial complex I in NADH oxidation has long been debated. Here, we took advantage of natural Trypanosoma cruzi mutants which present conspicuous deletions in ND4, ND5 and ND7 genes coding for complex I subunits to further investigate its functionality. Mitochondrial bioenergetics of wild type and complex I mutants showed no significant differences in oxygen consumption or respiratory control ratios in the presence of NADH-linked substrates or FADH(2)-generating succinate. No correlation could be established between mitochondrial membrane potentials and ND deletions. Since release of reactive oxygen species occurs at complex I, we measured mitochondrial H(2)O(2) formation induced by different substrates. Significant differences not associated to ND deletions were observed among the parasite isolates, demonstrating that these mutations are not important for the control of oxidant production. Our data support the notion that complex I has a limited function in T. cruzi.

  13. Mitochondrial aldehyde dehydrogenase obliterates insulin resistance-induced cardiac dysfunction through deacetylation of PGC-1α (United States)

    Hu, Nan; Ren, Jun; Zhang, Yingmei


    Insulin resistance contributes to the high prevalence of type 2 diabetes mellitus, leading to cardiac anomalies. Emerging evidence depicts a pivotal role for mitochondrial injury in oxidative metabolism and insulin resistance. Mitochondrial aldehyde dehydrogenase (ALDH2) is one of metabolic enzymes detoxifying aldehydes although its role in insulin resistance remains elusive. This study was designed to evaluate the impact of ALDH2 overexpression on insulin resistance-induced myocardial damage and mechanisms involved with a focus on autophagy. Wild-type (WT) and transgenic mice overexpressing ALDH2 were fed sucrose or starch diet for 8 weeks and cardiac function and intracellular Ca2+ handling were assessed using echocardiographic and IonOptix systems. Western blot analysis was used to evaluate Akt, heme oxygenase-1 (HO-1), PGC-1α and Sirt-3. Our data revealed that sucrose intake provoked insulin resistance and compromised fractional shortening, cardiomyocyte function and intracellular Ca2+ handling (p 0.05), mitochondrial injury (elevated ROS generation, suppressed NAD+ and aconitase activity, p < 0.05 for all), the effect of which was ablated by ALDH2. In vitro incubation of the ALDH2 activator Alda-1, the Sirt3 activator oroxylin A and the histone acetyltransferase inhibitor CPTH2 rescued insulin resistance-induced changes in aconitase activity and cardiomyocyte function (p < 0.05). Inhibiting Sirt3 deacetylase using 5-amino-2-(4-aminophenyl) benzoxazole negated Alda-1-induced cardioprotective effects. Taken together, our data suggest that ALDH2 serves as an indispensable cardioprotective factor against insulin resistance-induced cardiomyopathy with a mechanism possibly associated with facilitation of the Sirt3-dependent PGC-1α deacetylation. PMID:27634872

  14. Mitochondrial compromise in 3-year old patas monkeys exposed in utero to human-equivalent antiretroviral therapies. (United States)

    Liu, Yongmin; Shim Park, Eunwoo; Gibbons, Alexander T; Shide, Eric D; Divi, Rao L; Woodward, Ruth A; Poirier, Miriam C


    Antiretroviral (ARV) drug therapy, given during pregnancy for prevention of mother-to-child transmission of human immunodeficiency virus 1 (HIV-1), induces fetal mitochondrial dysfunction in some children. However, the persistence/reversibility of that dysfunction is unclear. Here we have followed Erythrocebus patas (patas) monkey offspring for up to 3 years of age (similar in development to a 15-year old human) after exposure of the dams to human-equivalent in utero ARV exposure protocols. Pregnant patas dams (3-5/exposure group) were given ARV drug combinations that included zidovudine (AZT)/lamivudine (3TC)/abacavir (ABC), or AZT/3TC/nevirapine (NVP), for the last 10 weeks (50%) of gestation. Infants kept for 1 and 3 years also received drug for the first 6 weeks of life. In offpsring at birth, 1 and 3 years of age mitochondrial morphology, examined by electron microscopy (EM), was compromised compared to the unexposed controls. Mitochondrial DNA (mtDNA), measured by hybrid capture chemiluminescence assay (HCCA) was depleted in hearts of patas exposed to AZT/3TC/NVP at all ages (P year-old patas offspring was ∼50% reduced in AZT/3TC/ABC-exposed patas (P year-old patas sustain persistent mitochondrial dysfunction as a result of perinatal ARV drug exposure. Environ. Mol. Mutagen. 57:526-534, 2016. © 2016 Wiley Periodicals, Inc.

  15. The ET axis mediates arrhythmogenesis and compromised cardiac function in two cardiomyopathy models

    Institute of Scientific and Technical Information of China (English)

    YuFENG; De-zaiDAI; YuanZHANG; Hai-boHE; Min-youQI; YinDAI; FengYU


    AIM Endothelin 1(ET-1), a potent vasoconstrictor peptide, is also regarded as an important etiological factor involved in many cardiac diseases like heart failure and cardiac hypertrophy. It mediates pathologic changes by forming an """"ET axis"""" at the upstream to ion channels, such as stimulating oxidant stress, eliciting cardiac remodeling by proliferation of cardiomyocytes, inducing apoptosis, affecting signal transduction pathway, and modulating intranuclear gene transcription. The purpose of this study was to investigate the pivotal role by ET axis in worsening arrhythmias and cardiac function in experimental hypertrophic cardiomyopathy (HCM) and heart failure (HF) models. METHODS The rat HCM model was induced by s.c L-thyroxin (L-thy, 0.2mg/Kg/d) for 10d,

  16. Isolating the segment of the mitochondrial electron transport chain responsible for mitochondrial damage during cardiac ischemia

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Qun; Yin, Guotian; Stewart, Sarah; Hu, Ying [Department of Medicine, Division of Cardiology, Case Western Reserve University, Cleveland, OH 44106 (United States); Lesnefsky, Edward J., E-mail: [Department of Medicine, Division of Cardiology, Case Western Reserve University, Cleveland, OH 44106 (United States); Medical Service, Louis Stokes Veterans Affairs Medical Center, Cleveland, OH 44106 (United States)


    Ischemia damages the mitochondrial electron transport chain (ETC), mediated in part by damage generated by the mitochondria themselves. Mitochondrial damage resulting from ischemia, in turn, leads to cardiac injury during reperfusion. The goal of the present study was to localize the segment of the ETC that produces the ischemic mitochondrial damage. We tested if blockade of the proximal ETC at complex I differed from blockade distal in the chain at cytochrome oxidase. Isolated rabbit hearts were perfused for 15 min followed by 30 min stop-flow ischemia at 37 {sup o}C. Amobarbital (2.5 mM) or azide (5 mM) was used to block proximal (complex I) or distal (cytochrome oxidase) sites in the ETC. Time control hearts were buffer-perfused for 45 min. Subsarcolemmal mitochondria (SSM) and interfibrillar mitochondria (IFM) were isolated. Ischemia decreased cytochrome c content in SSM but not in IFM compared to time control. Blockade of electron transport at complex I preserved the cytochrome c content in SSM. In contrast, blockade of electron transport at cytochrome oxidase with azide did not retain cytochrome c in SSM during ischemia. Since blockade of electron transport at complex III also prevented cytochrome c loss during ischemia, the specific site that elicits mitochondrial damage during ischemia is likely located in the segment between complex III and cytochrome oxidase.

  17. Assessment of cardiac function in mice lacking the mitochondrial calcium uniporter. (United States)

    Holmström, Kira M; Pan, Xin; Liu, Julia C; Menazza, Sara; Liu, Jie; Nguyen, Tiffany T; Pan, Haihui; Parks, Randi J; Anderson, Stasia; Noguchi, Audrey; Springer, Danielle; Murphy, Elizabeth; Finkel, Toren


    Mitochondrial calcium is thought to play an important role in the regulation of cardiac bioenergetics and function. The entry of calcium into the mitochondrial matrix requires that the divalent cation pass through the inner mitochondrial membrane via a specialized pore known as the mitochondrial calcium uniporter (MCU). Here, we use mice deficient of MCU expression to rigorously assess the role of mitochondrial calcium in cardiac function. Mitochondria isolated from MCU(-/-) mice have reduced matrix calcium levels, impaired calcium uptake and a defect in calcium-stimulated respiration. Nonetheless, we find that the absence of MCU expression does not affect basal cardiac function at either 12 or 20months of age. Moreover, the physiological response of MCU(-/-) mice to isoproterenol challenge or transverse aortic constriction appears similar to control mice. Thus, while mitochondria derived from MCU(-/-) mice have markedly impaired mitochondrial calcium handling, the hearts of these animals surprisingly appear to function relatively normally under basal conditions and during stress.

  18. Sepsis-induced cardiac mitochondrial dysfunction involves altered mitochondrial-localization of tyrosine kinase Src and tyrosine phosphatase SHP2.

    Directory of Open Access Journals (Sweden)

    Qun S Zang

    Full Text Available Our previous research demonstrated that sepsis produces mitochondrial dysfunction with increased mitochondrial oxidative stress in the heart. The present study investigated the role of mitochondria-localized signaling molecules, tyrosine kinase Src and tyrosine phosphatase SHP2, in sepsis-induced cardiac mitochondrial dysfunction using a rat pneumonia-related sepsis model. SD rats were given an intratracheal injection of Streptococcus pneumoniae, 4×10(6 CFU per rat, (or vehicle for shams; heart tissues were then harvested and subcellular fractions were prepared. By Western blot, we detected a gradual and significant decrease in Src and an increase in SHP2 in cardiac mitochondria within 24 hours post-inoculation. Furthermore, at 24 hours post-inoculation, sepsis caused a near 70% reduction in tyrosine phosphorylation of all cardiac mitochondrial proteins. Decreased tyrosine phosphorylation of certain mitochondrial structural proteins (porin, cyclophilin D and cytochrome C and functional proteins (complex II subunit 30kD and complex I subunit NDUFB8 were evident in the hearts of septic rats. In vitro, pre-treatment of mitochondrial fractions with recombinant active Src kinase elevated OXPHOS complex I and II-III activity, whereas the effect of SHP2 phosphatase was opposite. Neither Src nor SHP2 affected complex IV and V activity under the same conditions. By immunoprecipitation, we showed that Src and SHP2 consistently interacted with complex I and III in the heart, suggesting that complex I and III contain putative substrates of Src and SHP2. In addition, in vitro treatment of mitochondrial fractions with active Src suppressed sepsis-associated mtROS production and protected aconitase activity, an indirect marker of mitochondrial oxidative stress. On the contrary, active SHP2 phosphatase overproduced mtROS and deactivated aconitase under the same in vitro conditions. In conclusion, our data suggest that changes in mitochondria

  19. Electrocardiography as an early cardiac screening test in children with mitochondrial disease

    Directory of Open Access Journals (Sweden)

    Ran Baik


    Full Text Available Purpose : To evaluate myocardial conductivity to understand cardiac involvement in patients with mitochondrial disease. Methods : We performed retrospective study on fifty-seven nonspecific mitochondrial encephalopathy patients with no clinical cardiac manifestations. The patients were diagnosed with mitochondrial respiratory chain complex defects through biochemical enzyme assays of muscle tissue. We performed standard 12-lead electrocardiography (ECG on all patients. Results : ECG abnormalities were observed in 30 patients (52.6%. Prolongation of the QTc interval (&gt;440 ms was seen in 19 patients (33.3%, widening of the corrected QRS interval in 15 (26.3%, and bundle branch block in four (7.0%. Atrioventricular block, premature atrial contraction and premature ventricular contraction were seen in two patients each (3.5% and Wolff-Parkinson-White syndrome in one patient (1.8%. Conclusion : Given this finding, we recommend active screening with ECG in patients with mitochondrial disease even in patients without obvious cardiac manifestation.

  20. Sexual Dimorphism in the Alterations of Cardiac Muscle Mitochondrial Bioenergetics Associated to the Ageing Process. (United States)

    Colom, Bartomeu; Oliver, Jordi; Garcia-Palmer, Francisco J


    The incidence of cardiac disease is age and sex dependent, but the mechanisms governing these associations remain poorly understood. Mitochondria are the organelles in charge of producing energy for the cells, and their malfunction has been linked to cardiovascular disease and heart failure. Interestingly, heart mitochondrial content and functionality are also age and sex dependent. Here we investigated the combinatory effects of age and sex in mitochondrial bioenergetics that could help to understand their role on cardiac disease. Cardiac mitochondria from 6- and 24-month-old male and female Wistar rats were isolated, and the enzymatic activities of the oxidative-phosphorylative complexes I, III, and IV and ATPase, as well as the protein levels of complex IV, β-ATPase, and mitochondrial transcription factor A (TFAM), were measured. Furthermore, heart DNA content, citrate synthase activity, mitochondrial protein content, oxygen consumption, and H2O2 generation were also determined. Results showed a reduction in heart mitochondrial mass and functionality with age that correlated with increased H2O2 generation. Moreover, sex-dependent differences were found in several of these parameters. In particular, old females exhibited a significant loss of mitochondrial function and increased relative H2O2 production compared with their male counterparts. The results demonstrate a sex dimorphism in the age-associated defects on cardiac mitochondrial function.

  1. Cardiac mitochondrial energy metabolism in heart failure: Role of cardiolipin and sirtuins. (United States)

    Dolinsky, Vernon W; Cole, Laura K; Sparagna, Genevieve C; Hatch, Grant M


    Mitochondrial oxidation of fatty acids accounts for the majority of cardiac ATP production in the heart. Fatty acid utilization by cardiac mitochondria is controlled at the level of fatty acid uptake, lipid synthesis, mobilization and mitochondrial import and oxidation. Consequently defective mitochondrial function appears to be central to the development of heart failure. Cardiolipin is a key mitochondrial phospholipid required for the activity of the electron transport chain. In heart failure, loss of cardiolipin and tetralinoleoylcardiolipin helps to fuel the generation of excessive reactive oxygen species that are a by-product of inefficient mitochondrial electron transport chain complexes I and III. In this vicious cycle, reactive oxygen species generate lipid peroxides and may, in turn, cause oxidation of cardiolipin catalyzed by cytochrome c leading to cardiomyocyte apoptosis. Hence, preservation of cardiolipin and mitochondrial function may be keys to the prevention of heart failure development. In this review, we summarize cardiac energy metabolism and the important role that fatty acid uptake and metabolism play in this process and how defects in these result in heart failure. We highlight the key role that cardiolipin and sirtuins play in cardiac mitochondrial β-oxidation. In addition, we review the potential of pharmacological modulation of cardiolipin through the polyphenolic molecule resveratrol as a sirtuin-activator in attenuating mitochondrial dysfunction. Finally, we provide novel experimental evidence that resveratrol treatment increases cardiolipin in isolated H9c2 cardiac myocytes and tetralinoleoylcardiolipin in the heart of the spontaneously hypertensive rat and hypothesize that this leads to improvement in mitochondrial function. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk.

  2. Interaction of TNF with angiotensin II contributes to mitochondrial oxidative stress and cardiac damage in rats.

    Directory of Open Access Journals (Sweden)

    Nithya Mariappan

    Full Text Available Recent evidence suggests that tumor necrosis factor alpha (TNF and angiotensin II (ANGII induce oxidative stress contribute to cardiovascular disease progression. Here, we examined whether an interaction between TNF and ANGII contributes to altered cardiac mitochondrial biogenesis and ATP production to cause cardiac damage in rats. Rats received intraperitoneal injections of TNF (30 µg/kg, TNF + losartan (LOS, 1 mg/kg, or vehicle for 5 days. Left ventricular (LV function was measured using echocardiography. Rats were sacrificed and LV tissues removed for gene expression, electron paramagnetic resonance and mitochondrial assays. TNF administration significantly increased expression of the NADPH oxidase subunit, gp91phox, and the angiotensin type 1 receptor (AT-1R and decreased eNOS in the LV of rats. Rats that received TNF only had increased production rates of superoxide, peroxynitrite and total reactive oxygen species (ROS in the cytosol and increased production rates of superoxide and hydrogen peroxide in mitochondria. Decreased activities of mitochondrial complexes I, II, and III and mitochondrial genes were observed in rats given TNF. In addition, TNF administration also resulted in a decrease in fractional shortening and an increase in Tei index, suggesting diastolic dysfunction. TNF administration with concomitant LOS treatment attenuated mitochondrial damage, restored cardiac function, and decreased expression of AT1-R and NADPH oxidase subunits. Mitochondrial biogenesis and function is severely impaired by TNF as evidenced by downregulation of mitochondrial genes and increased free radical production, and may contribute to cardiac damage. These defects are independent of the downregulation of mitochondrial gene expression, suggesting novel mechanisms for mitochondrial dysfunction in rats given TNF.

  3. The Mitochondrial Calcium Uniporter Matches Energetic Supply with Cardiac Workload during Stress and Modulates Permeability Transition

    Directory of Open Access Journals (Sweden)

    Timothy S. Luongo


    Full Text Available Cardiac contractility is mediated by a variable flux in intracellular calcium (Ca2+, thought to be integrated into mitochondria via the mitochondrial calcium uniporter (MCU channel to match energetic demand. Here, we examine a conditional, cardiomyocyte-specific, mutant mouse lacking Mcu, the pore-forming subunit of the MCU channel, in adulthood. Mcu−/− mice display no overt baseline phenotype and are protected against mCa2+ overload in an in vivo myocardial ischemia-reperfusion injury model by preventing the activation of the mitochondrial permeability transition pore, decreasing infarct size, and preserving cardiac function. In addition, we find that Mcu−/− mice lack contractile responsiveness to acute β-adrenergic receptor stimulation and in parallel are unable to activate mitochondrial dehydrogenases and display reduced bioenergetic reserve capacity. These results support the hypothesis that MCU may be dispensable for homeostatic cardiac function but required to modulate Ca2+-dependent metabolism during acute stress.

  4. The Mitochondrial Calcium Uniporter Matches Energetic Supply with Cardiac Workload during Stress and Modulates Permeability Transition. (United States)

    Luongo, Timothy S; Lambert, Jonathan P; Yuan, Ancai; Zhang, Xueqian; Gross, Polina; Song, Jianliang; Shanmughapriya, Santhanam; Gao, Erhe; Jain, Mohit; Houser, Steven R; Koch, Walter J; Cheung, Joseph Y; Madesh, Muniswamy; Elrod, John W


    Cardiac contractility is mediated by a variable flux in intracellular calcium (Ca(2+)), thought to be integrated into mitochondria via the mitochondrial calcium uniporter (MCU) channel to match energetic demand. Here, we examine a conditional, cardiomyocyte-specific, mutant mouse lacking Mcu, the pore-forming subunit of the MCU channel, in adulthood. Mcu(-/-) mice display no overt baseline phenotype and are protected against mCa(2+) overload in an in vivo myocardial ischemia-reperfusion injury model by preventing the activation of the mitochondrial permeability transition pore, decreasing infarct size, and preserving cardiac function. In addition, we find that Mcu(-/-) mice lack contractile responsiveness to acute β-adrenergic receptor stimulation and in parallel are unable to activate mitochondrial dehydrogenases and display reduced bioenergetic reserve capacity. These results support the hypothesis that MCU may be dispensable for homeostatic cardiac function but required to modulate Ca(2+)-dependent metabolism during acute stress.

  5. Mitochondrial approaches to protect against cardiac ischemia and reperfusion injury

    Directory of Open Access Journals (Sweden)

    Amadou K.S. Camara


    Full Text Available The mitochondrion is a vital component in cellular energy metabolism and intracellular signaling processes. Mitochondria are involved in a myriad of complex signaling cascades regulating cell death vs. survival. Importantly, mitochondrial dysfunction and the resulting oxidative and nitrosative stress are central in the pathogenesis of numerous human maladies including cardiovascular diseases, neurodegenerative diseases, diabetes, and retinal diseases, many of which are related. This review will examine the emerging understanding of the role of mitochondria in the etiology and progression of cardiovascular diseases and will explore potential therapeutic benefits of targeting the organelle in attenuating the disease process. Indeed, recent advances in mitochondrial biology have led to selective targeting of drugs designed to modulate or manipulate mitochondrial function, to the use of light therapy directed to the mitochondrial function, and to modification of the mitochondrial genome for potential therapeutic benefit. The approach to rationally treat mitochondrial dysfunction could lead to more effective interventions in cardiovascular diseases that to date have remained elusive. The central premise of this review is that if mitochondrial abnormalities contribute to the etiology of cardiovascular diseases (e.g. ischemic heart disease, alleviating the mitochondrial dysfunction will contribute to mitigating the severity or progression of the disease. To this end, this review will provide an overview of our current understanding of mitochondria function in cardiovascular diseases as well as the potential role for targeting mitochondria with potential drugs or other interventions that lead to protection against cell injury.

  6. Characteristics of the rat cardiac sphingolipid pool in two mitochondrial subpopulations. (United States)

    Monette, Jeffrey S; Gómez, Luis A; Moreau, Régis F; Bemer, Brett A; Taylor, Alan W; Hagen, Tory M


    Mitochondrial sphingolipids play a diverse role in normal cardiac function and diseases, yet a precise quantification of cardiac mitochondrial sphingolipids has never been performed. Therefore, rat heart interfibrillary mitochondria (IFM) and subsarcolemmal mitochondria (SSM) were isolated, lipids extracted, and sphingolipids quantified by LC-tandem mass spectrometry. Results showed that sphingomyelin (approximately 10,000 pmol/mg protein) was the predominant sphingolipid regardless of mitochondrial subpopulation, and measurable amounts of ceramide (approximately 70 pmol/mg protein) sphingosine, and sphinganine were also found in IFM and SSM. Both mitochondrial populations contained similar quantities of sphingolipids except for ceramide which was much higher in SSM. Analysis of sphingolipid isoforms revealed ten different sphingomyelins and six ceramides that differed from 16- to 24-carbon units in their acyl side chains. Sub-fractionation experiments further showed that sphingolipids are a constituent part of the inner mitochondrial membrane. Furthermore, inner membrane ceramide levels were 32% lower versus whole mitochondria (45 pmol/mg protein). Three ceramide isotypes (C20-, C22-, and C24-ceramide) accounted for the lower amounts. The concentrations of the ceramides present in the inner membranes of SSM and IFM differed greatly. Overall, mitochondrial sphingolipid content reflected levels seen in cardiac tissue, but the specific ceramide distribution distinguished IFM and SSM from each other.

  7. Tissue-specific and substrate-specific mitochondrial bioenergetics in feline cardiac and skeletal muscles

    DEFF Research Database (Denmark)

    Christiansen, Liselotte Bruun; Dela, Flemming; Koch, Jørgen;


    fibers. Biopsies of left ventricular cardiac muscle and soleus muscle, a type I-rich oxidative skeletal muscle, were obtained from 15 healthy domestic cats. Enzymatic activity of citrate synthase (CS), a biomarker of mitochondrial content, was measured. Mitochondrial OXPHOS capacity with various kinds...... of non-fatty-acid substrates and fatty-acid substrate in permeabilized muscle fiber was measured by using high-resolution respirometry. CS activity in the heart was 3 times higher than in the soleus muscle. Mitochondrial state 3 respiration, ADP-stimulated respiration, with complex I-linked and complex I...

  8. Mitochondrial reprogramming through cardiac oxygen sensors in ischaemic heart disease. (United States)

    Cadenas, Susana; Aragonés, Julián; Landázuri, Manuel O


    Under hypoxic conditions, mitochondria can represent a threat to the cell because of their capacity to generate toxic reactive oxygen species (ROS). However, cardiomyocytes are equipped with an oxygen-sensing pathway that involves prolyl hydroxylase oxygen sensors and hypoxia-inducible factors (HIFs), which induces a tightly regulated programme to keep ischaemic mitochondrial activity under control. The aim of this review is to provide an update on the pathways leading to mitochondrial reprogramming, which occurs in the myocardium during ischaemia, with particular emphasis on those induced by HIF activation. We start by studying the mechanisms of mitochondrial damage during ischaemia and upon reperfusion, highlighting the importance of the formation of the mitochondrial permeability transition pore during reperfusion and its consequences for cardiomyocyte survival. Next, we analyse hypoxia-induced metabolic reprogramming through HIF and its important consequences for mitochondrial bioenergetics, as well as the phenomenon known as the hibernating myocardium. Subsequently, we examine the mechanisms underlying ischaemic preconditioning, focusing, in particular, on those that involve the HIF pathway, such as adenosine signalling, sub-lethal ROS generation, and nitric oxide production. Finally, the role of the mitochondrial uncoupling proteins in ischaemia tolerance is discussed.

  9. Ginsenoside Rg3 improves cardiac mitochondrial population quality: Mimetic exercise training

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Mengwei [Key Laboratory of State General Administration of Sport, Shanghai Research Institute of Sports Science, Shanghai 200031 (China); Huang, Chenglin [Shanghai Key Laboratory of Vascular Biology, Department of Hypertension and Pharmacology, Ruijin Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai 200025 (China); Wang, Cheng; Zheng, Jianheng; Zhang, Peng; Xu, Yangshu [Key Laboratory of State General Administration of Sport, Shanghai Research Institute of Sports Science, Shanghai 200031 (China); Chen, Hong, E-mail: [Shanghai Key Laboratory of Vascular Biology, Department of Hypertension and Pharmacology, Ruijin Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai 200025 (China); Shen, Weili, E-mail: [Shanghai Key Laboratory of Vascular Biology, Department of Hypertension and Pharmacology, Ruijin Hospital, Shanghai Jiaotong University, School of Medicine, Shanghai 200025 (China)


    Highlights: •Rg3 is an ergogenic aid. •Rg3 improves mitochondrial antioxidant capacity. •Rg3 regulates mitochondria dynamic remodeling. •Rg3 alone matches some the benefits of aerobic exercise. -- Abstract: Emerging evidence indicates exercise training could mediate mitochondrial quality control through the improvement of mitochondrial dynamics. Ginsenoside Rg3 (Rg3), one of the active ingredients in Panax ginseng, is well known in herbal medicine as a tonic and restorative agent. However, the molecular mechanism underlying the beneficial effects of Rg3 has been elusive. In the present study, we compared the effects of Rg3 administration with aerobic exercise on mitochondrial adaptation in cardiac muscle tissue of Sprague–Dawley (SD) rats. Three groups of SD rats were studied: (1) sedentary control, (2) Rg3-treated and (3) aerobic exercise trained. Both aerobic exercise training and Rg3 supplementation enhanced peroxisome proliferator-activated receptor coactivator 1 alpha (PGC-1α) and nuclear factor-E2-related factor 2 (Nrf2) protein levels in cardiac muscle. The activation of PGC-1α led to increased mRNA levels of mitochondrial transcription factor A (Tfam) and nuclear related factor 1(Nrf1), these changes were accompanied by increases in mitochondrial DNA copy number and complex protein levels, while activation of Nrf2 increased levels of phase II detoxifying enzymes, including nicotinamide adenine dinucleotide phosphate:quinone oxidoreductase 1(NQO1), superoxide dismutase (MnSOD) and catalase. Aerobic exercise also enhanced mitochondrial autophagy pathway activity, including increased conversion of LC3-I to LC3-II and greater expression of beclin1 and autophagy-related protein 7 (ATG7), these effects of aerobic exercise are comparable to that of Rg3. These results demonstrate that Rg3 mimics improved cardiac adaptations to exercise by regulating mitochondria dynamic remodeling and enhancing the quantity and quality of mitochondria.

  10. Activation of mitochondrial STAT-3 and reduced mitochondria damage during hypothermia treatment for post-cardiac arrest myocardial dysfunction. (United States)

    Huang, Chien-Hua; Tsai, Min-Shan; Chiang, Chih-Yen; Su, Yu-Jen; Wang, Tzung-Dau; Chang, Wei-Tien; Chen, Huei-Wen; Chen, Wen-Jone


    While therapeutic hypothermia improves the outcomes of individuals in cardiac arrest, the hemodynamic responses and mechanisms which underlie hypothermia-induced cardioprotection are not fully understood. Therefore, we investigated the mechanism by which induced hypothermia preserves cardiac function and protects against mitochondrial damage following cardiac arrest. Cardiac arrest was induced in adult male Wistar rats by asphyxiation for 8.5 min. Following resuscitation, the animals were randomly assigned to a hypothermia (32 °C) or normothermia (37 °C) group. Monitoring results showed that cardiac output at the fourth hour after resuscitation was significantly better in rats treated with hypothermia when compared to rats treated with normothermia (P mitochondrial permeability transition pores occurred less frequently in the hypothermic group. While complex I/III activity in the electron transport reaction was damaged after cardiac arrest and resuscitation, the degree of injury was ameliorated by hypothermia treatment (P mitochondrial integrity and electron transport activity.

  11. Deregulation of mitochondrial functions provoked by long-chain fatty acid accumulating in long-chain 3-hydroxyacyl-CoA dehydrogenase and mitochondrial permeability transition deficiencies in rat heart--mitochondrial permeability transition pore opening as a potential contributing pathomechanism of cardiac alterations in these disorders. (United States)

    Cecatto, Cristiane; Hickmann, Fernanda H; Rodrigues, Marília D N; Amaral, Alexandre U; Wajner, Moacir


    Mitochondrial trifunctional protein and long-chain 3-hydroxyacyl-CoA dehydrogenase deficiencies are fatty acid oxidation disorders biochemically characterized by tissue accumulation of long-chain fatty acids and derivatives, including the monocarboxylic long-chain 3-hydroxy fatty acids (LCHFAs) 3-hydroxytetradecanoic acid (3HTA) and 3-hydroxypalmitic acid (3HPA). Patients commonly present severe cardiomyopathy for which the pathogenesis is still poorly established. We investigated the effects of 3HTA and 3HPA, the major metabolites accumulating in these disorders, on important parameters of mitochondrial homeostasis in Ca(2+) -loaded heart mitochondria. 3HTA and 3HPA significantly decreased mitochondrial membrane potential, the matrix NAD(P)H pool and Ca(2+) retention capacity, and also induced mitochondrial swelling. These fatty acids also provoked a marked decrease of ATP production reflecting severe energy dysfunction. Furthermore, 3HTA-induced mitochondrial alterations were completely prevented by the classical mitochondrial permeability transition (mPT) inhibitors cyclosporin A and ADP, as well as by ruthenium red, a Ca(2+) uptake blocker, indicating that LCHFAs induced Ca(2+)-dependent mPT pore opening. Milder effects only achieved at higher doses of LCHFAs were observed in brain mitochondria, implying a higher vulnerability of heart to these fatty acids. By contrast, 3HTA and docosanoic acids did not change mitochondrial homeostasis, indicating selective effects for monocarboxylic LCHFAs. The present data indicate that the major LCHFAs accumulating in mitochondrial trifunctional protein and long-chain 3-hydroxyacyl-CoA dehydrogenase deficiencies induce mPT pore opening, compromising Ca(2+) homeostasis and oxidative phosphorylation more intensely in the heart. It is proposed that these pathomechanisms may contribute at least in part to the severe cardiac alterations characteristic of patients affected by these diseases.

  12. Sodium hydrosulfide attenuates hyperhomocysteinemia rat myocardial injury through cardiac mitochondrial protection. (United States)

    Wang, Yuwen; Shi, Sa; Dong, Shiyun; Wu, Jichao; Song, Mowei; Zhong, Xin; Liu, Yanhong


    Hydrogen sulfide (H2S) plays an important role during rat myocardial injury. However, little is known about the role of H2S in hyperhomocysteinemia (HHcy)-induced cardiac dysfunction as well as the underlying mechanisms. In this study, we investigated whether sodium hydrosulfide (NaHS, a H2S donor) influences methionine-induced HHcy rat myocardial injury in intact rat hearts and primary neonatal rat cardiomyocytes. HHcy rats were induced by methionine (2.0 g/kg) and the daily administration of 80 μmol/L NaHS in the HHcy + NaHS treatment group. At the end of 4, 8, and 12 weeks, the ultrastructural alterations and functions of the hearts were observed using transmission electron microscopy and echocardiography system. The percentage of apoptotic cardiomyocytes, the mitochondrial membrane potential, and the production of reactive oxygen species (ROS) were measured. The expressions of cystathionine-γ-lyase (CSE), Bax and Bcl-2, caspase-3, phospho-endothelial nitric oxide synthase and the mitochondrial NOX4 and cytochrome c were analyzed by Western blotting. The results showed the cardiac dysfunction, the ultrastructural changes, and the apoptotic rate increase in the HHcy rat hearts. In the primary neonatal rat cardiomyocytes of HHcy group, ROS production was increased markedly, whereas the expression of CSE was decreased. However, treatment with NaHS significantly improved the HHcy rat hearts function, the ultrastructural changes, and decreased the levels of ROS in the primary neonatal rat cardiomyocytes administrated with HHcy group. Furthermore, NaHS down-regulated the expression of mitochondrial NOX4 and caspase-3 and Bax and inhibited the release of cytochrome c from mitochondria. In conclusion, H2S is involved in the attenuation of HHcy myocardial injury through the protection of cardiac mitochondria.

  13. Cardiac mitochondrial damage and biogenesis in a chronic model of type 1 diabetes. (United States)

    Shen, Xia; Zheng, Shirong; Thongboonkerd, Visith; Xu, Ming; Pierce, William M; Klein, Jon B; Epstein, Paul N


    Diabetic cardiomyopathy is a common complication leading to heightened risk of heart failure and death. In the present report, we performed proteomic analysis on total cardiac proteins from the OVE26 mouse model of type 1 diabetes to identify protein changes that may contribute to diabetic cardiomyopathy. This analysis revealed that a surprising high proportion (12 of 20) of the altered proteins that could be identified by mass spectrometry were of mitochondrial origin. All but one of these proteins were upregulated by diabetes. Quantitative RT-PCR, performed for two of these proteins, indicated that part of the upregulation was attributed to increased messenger RNA levels. Morphological study of diabetic hearts showed significantly increased mitochondrial area and number as well as focal regions with severe damage to mitochondria. Diabetic mitochondria also showed reduced respiratory control ratio (9.63 +/- 0.20 vs. 6.13 +/- 0.41, P factor A and two mitochondrial encoded proteins. Taken together, these results show that mitochondria are a primary target in the diabetic heart, probably due to oxidative stress, and that this damage coincides with and may stimulate mitochondrial biogenesis.

  14. Inhibition of leukotriene B4 receptor 1 attenuates lipopolysaccharide-induced cardiac dysfunction: role of AMPK-regulated mitochondrial function (United States)

    Sun, Meng; Wang, Rui; Han, Qinghua


    Leukotriene B4 (LTB4)-mediated leukocyte recruitment and inflammatory cytokine production make crucial contributions to chronic inflammation and sepsis; however, the role of LTB4 in lipopolysaccharide (LPS)-induced cardiac dysfunction remains unclear. Therefore, the present study addressed this issue using an LTB4 receptor 1 (BLT1) inhibitor. Administration of LPS to mice resulted in decreased cardiovascular function. Inhibition of LTB4/BLT1 with the BLT1 inhibitor U75302 significantly improved survival and attenuated the LPS-induced acute cardiac dysfunction. During LPS challenge, the phosphorylated AMPK/ACC signaling pathway was slightly activated, and this effect was enhanced by U75302. Additionally, pNF-κB, Bax and cleaved caspase-3 were upregulated by LPS, and Bcl-2, IκB-α, mitochondrial complex I, complex II, and OPA1 were downregulated; however, these effects were reversed by U75302. The results indicated that the BLT1 antagonist suppressed cardiac apoptosis, inflammation, and mitochondrial impairment. Furthermore, the protection provided by the BLT1 inhibitor against LPS-induced cardiac dysfunction was significantly reversed by the AMPK inhibitor Compound C. In conclusion, inhibiting the LTB4/BLT1 signaling pathway via AMPK activation is a potential treatment strategy for septic cardiac dysfunction because it efficiently attenuates cardiac apoptosis, which may occur via the inhibition of inflammation and mitochondrial dysfunction. PMID:28290498

  15. The transcriptional coactivator PGC-1alpha is essential for maximal and efficient cardiac mitochondrial fatty acid oxidation and lipid homeostasis. (United States)

    Lehman, John J; Boudina, Sihem; Banke, Natasha Hausler; Sambandam, Nandakumar; Han, Xianlin; Young, Deanna M; Leone, Teresa C; Gross, Richard W; Lewandowski, E Douglas; Abel, E Dale; Kelly, Daniel P


    High-capacity mitochondrial ATP production is essential for normal function of the adult heart, and evidence is emerging that mitochondrial derangements occur in common myocardial diseases. Previous overexpression studies have shown that the inducible transcriptional coactivator peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1alpha is capable of activating postnatal cardiac myocyte mitochondrial biogenesis. Recently, we generated mice deficient in PGC-1alpha (PGC-1alpha(-/-) mice), which survive with modestly blunted postnatal cardiac growth. To determine if PGC-1alpha is essential for normal cardiac energy metabolic capacity, mitochondrial function experiments were performed on saponin-permeabilized myocardial fibers from PGC-1alpha(-/-) mice. These experiments demonstrated reduced maximal (state 3) palmitoyl-l-carnitine respiration and increased maximal (state 3) pyruvate respiration in PGC-1alpha(-/-) mice compared with PGC-1alpha(+/+) controls. ATP synthesis rates obtained during maximal (state 3) respiration in permeabilized myocardial fibers were reduced for PGC-1alpha(-/-) mice, whereas ATP produced per oxygen consumed (ATP/O), a measure of metabolic efficiency, was decreased by 58% for PGC-1alpha(-/-) fibers. Ex vivo isolated working heart experiments demonstrated that PGC-1alpha(-/-) mice exhibited lower cardiac power, reduced palmitate oxidation, and increased reliance on glucose oxidation, with the latter likely a compensatory response. (13)C NMR revealed that hearts from PGC-1alpha(-/-) mice exhibited a limited capacity to recruit triglyceride as a source for lipid oxidation during beta-adrenergic challenge. Consistent with reduced mitochondrial fatty acid oxidative enzyme gene expression, the total triglyceride content was greater in hearts of PGC-1alpha(-/-) mice relative to PGC-1alpha(+/+) following a fast. Overall, these results demonstrate that PGC-1alpha is essential for the maintenance of maximal, efficient cardiac

  16. Transcriptome-wide co-expression analysis identifies LRRC2 as a novel mediator of mitochondrial and cardiac function (United States)

    Leleu, Marion; Rowe, Glenn C.; Palygin, Oleg; Bukowy, John D.; Kuo, Judy; Rech, Monika; Hermans-Beijnsberger, Steffie; Schaefer, Sebastian; Adami, Eleonora; Creemers, Esther E.; Heinig, Matthias; Schroen, Blanche; Arany, Zoltan; Petretto, Enrico; Geurts, Aron M.


    Mitochondrial dysfunction contributes to myriad monogenic and complex pathologies. To understand the underlying mechanisms, it is essential to define the full complement of proteins that modulate mitochondrial function. To identify such proteins, we performed a meta-analysis of publicly available gene expression data. Gene co-expression analysis of a large and heterogeneous compendium of microarray data nominated a sub-population of transcripts that whilst highly correlated with known mitochondrial protein-encoding transcripts (MPETs), are not themselves recognized as generating proteins either localized to the mitochondrion or pertinent to functions therein. To focus the analysis on a medically-important condition with a strong yet incompletely understood mitochondrial component, candidates were cross-referenced with an MPET-enriched module independently generated via genome-wide co-expression network analysis of a human heart failure gene expression dataset. The strongest uncharacterized candidate in the analysis was Leucine Rich Repeat Containing 2 (LRRC2). LRRC2 was found to be localized to the mitochondria in human cells and transcriptionally-regulated by the mitochondrial master regulator Pgc-1α. We report that Lrrc2 transcript abundance correlates with that of β-MHC, a canonical marker of cardiac hypertrophy in humans and experimentally demonstrated an elevation in Lrrc2 transcript in in vitro and in vivo rodent models of cardiac hypertrophy as well as in patients with dilated cardiomyopathy. RNAi-mediated Lrrc2 knockdown in a rat-derived cardiomyocyte cell line resulted in enhanced expression of canonical hypertrophic biomarkers as well as increased mitochondrial mass in the context of increased Pgc-1α expression. In conclusion, our meta-analysis represents a simple yet powerful springboard for the nomination of putative mitochondrially-pertinent proteins relevant to cardiac function and enabled the identification of LRRC2 as a novel mitochondrially

  17. Enhanced Cardiac Akt/Protein Kinase B Signaling Contributes to Pathological Cardiac Hypertrophy in Part by Impairing Mitochondrial Function via Transcriptional Repression of Mitochondrion-Targeted Nuclear Genes (United States)

    Wende, Adam R.; O'Neill, Brian T.; Bugger, Heiko; Riehle, Christian; Tuinei, Joseph; Buchanan, Jonathan; Tsushima, Kensuke; Wang, Li; Caro, Pilar; Guo, Aili; Sloan, Crystal; Kim, Bum Jun; Wang, Xiaohui; Pereira, Renata O.; McCrory, Mark A.; Nye, Brenna G.; Benavides, Gloria A.; Darley-Usmar, Victor M.; Shioi, Tetsuo; Weimer, Bart C.


    Sustained Akt activation induces cardiac hypertrophy (LVH), which may lead to heart failure. This study tested the hypothesis that Akt activation contributes to mitochondrial dysfunction in pathological LVH. Akt activation induced LVH and progressive repression of mitochondrial fatty acid oxidation (FAO) pathways. Preventing LVH by inhibiting mTOR failed to prevent the decline in mitochondrial function, but glucose utilization was maintained. Akt activation represses expression of mitochondrial regulatory, FAO, and oxidative phosphorylation genes in vivo that correlate with the duration of Akt activation in part by reducing FOXO-mediated transcriptional activation of mitochondrion-targeted nuclear genes in concert with reduced signaling via peroxisome proliferator-activated receptor α (PPARα)/PGC-1α and other transcriptional regulators. In cultured myocytes, Akt activation disrupted mitochondrial bioenergetics, which could be partially reversed by maintaining nuclear FOXO but not by increasing PGC-1α. Thus, although short-term Akt activation may be cardioprotective during ischemia by reducing mitochondrial metabolism and increasing glycolysis, long-term Akt activation in the adult heart contributes to pathological LVH in part by reducing mitochondrial oxidative capacity. PMID:25535334

  18. Overexpression of ryanodine receptor type 1 enhances mitochondrial fragmentation and Ca2+-induced ATP production in cardiac H9c2 myoblasts. (United States)

    O-Uchi, Jin; Jhun, Bong Sook; Hurst, Stephen; Bisetto, Sara; Gross, Polina; Chen, Ming; Kettlewell, Sarah; Park, Jongsun; Oyamada, Hideto; Smith, Godfrey L; Murayama, Takashi; Sheu, Shey-Shing


    Ca(+) influx to mitochondria is an important trigger for both mitochondrial dynamics and ATP generation in various cell types, including cardiac cells. Mitochondrial Ca(2+) influx is mainly mediated by the mitochondrial Ca(2+) uniporter (MCU). Growing evidence also indicates that mitochondrial Ca(2+) influx mechanisms are regulated not solely by MCU but also by multiple channels/transporters. We have previously reported that skeletal muscle-type ryanodine receptor (RyR) type 1 (RyR1), which expressed at the mitochondrial inner membrane, serves as an additional Ca(2+) uptake pathway in cardiomyocytes. However, it is still unclear which mitochondrial Ca(2+) influx mechanism is the dominant regulator of mitochondrial morphology/dynamics and energetics in cardiomyocytes. To investigate the role of mitochondrial RyR1 in the regulation of mitochondrial morphology/function in cardiac cells, RyR1 was transiently or stably overexpressed in cardiac H9c2 myoblasts. We found that overexpressed RyR1 was partially localized in mitochondria as observed using both immunoblots of mitochondrial fractionation and confocal microscopy, whereas RyR2, the main RyR isoform in the cardiac sarcoplasmic reticulum, did not show any expression at mitochondria. Interestingly, overexpression of RyR1 but not MCU or RyR2 resulted in mitochondrial fragmentation. These fragmented mitochondria showed bigger and sustained mitochondrial Ca(2+) transients compared with basal tubular mitochondria. In addition, RyR1-overexpressing cells had a higher mitochondrial ATP concentration under basal conditions and showed more ATP production in response to cytosolic Ca(2+) elevation compared with nontransfected cells as observed by a matrix-targeted ATP biosensor. These results indicate that RyR1 possesses a mitochondrial targeting/retention signal and modulates mitochondrial morphology and Ca(2+)-induced ATP production in cardiac H9c2 myoblasts.

  19. Crosstalk between mitochondrial and sarcoplasmic reticulum Ca2+ cycling modulates cardiac pacemaker cell automaticity.

    Directory of Open Access Journals (Sweden)

    Yael Yaniv

    Full Text Available BACKGROUND: Mitochondria dynamically buffer cytosolic Ca(2+ in cardiac ventricular cells and this affects the Ca(2+ load of the sarcoplasmic reticulum (SR. In sinoatrial-node cells (SANC the SR generates periodic local, subsarcolemmal Ca(2+ releases (LCRs that depend upon the SR load and are involved in SANC automaticity: LCRs activate an inward Na(+-Ca(2+ exchange current to accelerate the diastolic depolarization, prompting the ensemble of surface membrane ion channels to generate the next action potential (AP. OBJECTIVE: To determine if mitochondrial Ca(2+ (Ca(2+ (m, cytosolic Ca(2+ (Ca(2+ (c-SR-Ca(2+ crosstalk occurs in single rabbit SANC, and how this may relate to SANC normal automaticity. RESULTS: Inhibition of mitochondrial Ca(2+ influx into (Ru360 or Ca(2+ efflux from (CGP-37157 decreased [Ca(2+](m to 80 ± 8% control or increased [Ca(2+](m to 119 ± 7% control, respectively. Concurrent with inhibition of mitochondrial Ca(2+ influx or efflux, the SR Ca(2+ load, and LCR size, duration, amplitude and period (imaged via confocal linescan significantly increased or decreased, respectively. Changes in total ensemble LCR Ca(2+ signal were highly correlated with the change in the SR Ca(2+ load (r(2 = 0.97. Changes in the spontaneous AP cycle length (Ru360, 111 ± 1% control; CGP-37157, 89 ± 2% control in response to changes in [Ca(2+](m were predicted by concurrent changes in LCR period (r(2 = 0.84. CONCLUSION: A change in SANC Ca(2+ (m flux translates into a change in the AP firing rate by effecting changes in Ca(2+ (c and SR Ca(2+ loading, which affects the characteristics of spontaneous SR Ca(2+ release.

  20. Mitochondrial DNA deletion mutations in adult mouse cardiac side population cells

    Energy Technology Data Exchange (ETDEWEB)

    Lushaj, Entela B., E-mail: [Division of Cardiothoracic Surgery, Department of Surgery, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53792 (United States); Lozonschi, Lucian; Barnes, Maria; Anstadt, Emily; Kohmoto, Takushi [Division of Cardiothoracic Surgery, Department of Surgery, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53792 (United States)


    We investigated the presence and potential role of mitochondrial DNA (mtDNA) deletion mutations in adult cardiac stem cells. Cardiac side population (SP) cells were isolated from 12-week-old mice. Standard polymerase chain reaction (PCR) was used to screen for the presence of mtDNA deletion mutations in (a) freshly isolated SP cells and (b) SP cells cultured to passage 10. When present, the abundance of mtDNA deletion mutation was analyzed in single cell colonies. The effect of different levels of deletion mutations on SP cell growth and differentiation was determined. MtDNA deletion mutations were found in both freshly isolated and cultured cells from 12-week-old mice. While there was no significant difference in the number of single cell colonies with mtDNA deletion mutations from any of the groups mentioned above, the abundance of mtDNA deletion mutations was significantly higher in the cultured cells, as determined by quantitative PCR. Within a single clonal cell population, the detectable mtDNA deletion mutations were the same in all cells and unique when compared to deletions of other colonies. We also found that cells harboring high levels of mtDNA deletion mutations (i.e. where deleted mtDNA comprised more than 60% of total mtDNA) had slower proliferation rates and decreased differentiation capacities. Screening cultured adult stem cells for mtDNA deletion mutations as a routine assessment will benefit the biomedical application of adult stem cells.


    Directory of Open Access Journals (Sweden)

    V. N. Poptsov


    Full Text Available Introduction. Acute antibody-mediated rejection (AMR is one of the severe complications of early and late period after heart transplantation (HT. Only few case reports and studies presented of mechanical circulatory support (MCS application for refractory acute rejection causing hemodynamic compromise. Aim. We report the case of a woman with cardiogenic shock caused by severe AMR that was successfully treatment by peripheral venoarterial extracorporeal membrane oxygenation (VA ECMO. Material and methods. In december 2014, a 60-year-old woman with dilated cardiomyopathy was operated for HT. The patient had a good initial cardiac allograft function and no and was discharged from ICU on the 4th day after HT. 1st endomyocardial biopsy (EMB (the 7th day after HT showed absence of acute cellular and antibody-mediated rejection. On the 11th day after HT patient aggravated and presented clinical signs of life-threatening acute cardiac allograft dysfunction: arterial blood pressure 78/49/38 mm Hg, HR 111 in min, CVP 20 mm Hg, PAP 47/34/25 mm Hg, PCWP 25 mm Hg, CI 1.5 l/min/m2, adrenalin 110 ng/kg/min, dopamine 15 mcg/kg/min. ECG showed impairment of systolic left (LVEF 25% and right (RVEF 15% ventricle function, left and right ventricle diffuse hypokinesis, thickness of IVS, LV and RV wall 1.7, 1.4 and 0.8 cm, tricuspid and mitral valve regurgitation 2–3 degrees. EMB presented AMR. In conscience peripheral VA ECMO was installed. We used peripheral transcutaneous cannulation technique via femoral vessels – arterial cannula 15 F, venous cannula – 23 F, vascular catheter 14 G for anterograde leg’s perfusion. ACT 130–150 sec. AMR therapy included: methylprednisolon pulse-therapy (10 mg/kg for 5 day, IgG, plasmapheresis (No 7, rituximab. Results. Under MCS by VA ECMO we noted quick improvement of hemodynamic, metabolic homeostasis and organ functions. On the 6th day of VA ECMO (blood flow 1.8 l/min: arterial blood pressure 133/81/54 mm Hg, CVP 5 mm

  2. Evaluation of Cardiac Mitochondrial Function by a Nuclear Imaging Technique using Technetium-99m-MIBI Uptake Kinetics

    Directory of Open Access Journals (Sweden)

    Shinro Matsuo


    Full Text Available Mitochondria play an important role in energy production for the cell. The proper function of a myocardial cell largely depends on the functional capacity of the mitochondria. Therefore it is necessary to establish a novel and reliable method for a non-invasive assessment of mitochondrial function and metabolism in humans. Although originally designed for evaluating myocardial perfusion, 99mTc-MIBI can be also used to evaluate cardiac mitochondrial function. In a clinical study on ischemic heart disease, reverse redistribution of 99mTc-MIBI was evident after direct percutaneous transluminal coronary angioplasty. The presence of increased washout of 99mTc-MIBI was associated with the infarct-related artery and preserved left ventricular function. In non-ischemic cardiomyopathy, an increased washout rate of 99mTc-MIBI, which correlated inversely with left ventricular ejection fraction, was observed in patients with congestive heart failure. Increased 99mTc-MIBI washout was also observed in mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS and in doxorubicin-induced cardiomyopathy. Noninvasive assessment of cardiac mitochondrial function could be greatly beneficial in monitoring possible cardiotoxic drug use and in the evaluation of cardiac damage in clinical medicine.

  3. Physical exercise regulates p53 activity targeting SCO2 and increases mitochondrial COX biogenesis in cardiac muscle with age.

    Directory of Open Access Journals (Sweden)

    Zhengtang Qi

    Full Text Available The purpose of this study was to outline the timelines of mitochondrial function, oxidative stress and cytochrome c oxidase complex (COX biogenesis in cardiac muscle with age, and to evaluate whether and how these age-related changes were attenuated by exercise. ICR/CD-1 mice were treated with pifithrin-μ (PFTμ, sacrificed and studied at different ages; ICR/CD-1 mice at younger or older ages were randomized to endurance treadmill running and sedentary conditions. The results showed that mRNA expression of p53 and its protein levels in mitochondria increased with age in cardiac muscle, accompanied by increased mitochondrial oxidative stress, reduced expression of COX subunits and assembly proteins, and decreased expression of most markers in mitochondrial biogenesis. Most of these age-related changes including p53 activity targeting cytochrome oxidase deficient homolog 2 (SCO2, p53 translocation to mitochondria and COX biogenesis were attenuated by exercise in older mice. PFTμ, an inhibitor blocking p53 translocation to mitochondria, increased COX biogenesis in older mice, but not in young mice. Our data suggest that physical exercise attenuates age-related changes in mitochondrial COX biogenesis and p53 activity targeting SCO2 and mitochondria, and thereby induces antisenescent and protective effects in cardiac muscle.

  4. Characterization of the Cardiac Overexpression of HSPB2 Reveals Mitochondrial and Myogenic Roles Supported by a Cardiac HspB2 Interactome.

    Directory of Open Access Journals (Sweden)

    Julianne H Grose

    Full Text Available Small Heat Shock Proteins (sHSPs are molecular chaperones that transiently interact with other proteins, thereby assisting with quality control of proper protein folding and/or degradation. They are also recruited to protect cells from a variety of stresses in response to extreme heat, heavy metals, and oxidative-reductive stress. Although ten human sHSPs have been identified, their likely diverse biological functions remain an enigma in health and disease, and much less is known about non-redundant roles in selective cells and tissues. Herein, we set out to comprehensively characterize the cardiac-restricted Heat Shock Protein B-2 (HspB2, which exhibited ischemic cardioprotection in transgenic overexpressing mice including reduced infarct size and maintenance of ATP levels. Global yeast two-hybrid analysis using HspB2 (bait and a human cardiac library (prey coupled with co-immunoprecipitation studies for mitochondrial target validation revealed the first HspB2 "cardiac interactome" to contain many myofibril and mitochondrial-binding partners consistent with the overexpression phenotype. This interactome has been submitted to the Biological General Repository for Interaction Datasets (BioGRID. A related sHSP chaperone HspB5 had only partially overlapping binding partners, supporting specificity of the interactome as well as non-redundant roles reported for these sHSPs. Evidence that the cardiac yeast two-hybrid HspB2 interactome targets resident mitochondrial client proteins is consistent with the role of HspB2 in maintaining ATP levels and suggests new chaperone-dependent functions for metabolic homeostasis. One of the HspB2 targets, glyceraldehyde 3-phosphate dehydrogenase (GAPDH, has reported roles in HspB2 associated phenotypes including cardiac ATP production, mitochondrial function, and apoptosis, and was validated as a potential client protein of HspB2 through chaperone assays. From the clientele and phenotypes identified herein, it is

  5. Chronic testosterone replacement exerts cardioprotection against cardiac ischemia-reperfusion injury by attenuating mitochondrial dysfunction in testosterone-deprived rats.

    Directory of Open Access Journals (Sweden)

    Wanpitak Pongkan

    Full Text Available Although testosterone deficiency is associated with increased risks of heart disease, the benefits of testosterone therapy are controversial. Moreover, current understanding on the cardiac effect of testosterone during cardiac ischemia-reperfusion (I/R periods is unclear. We tested the hypothesis that testosterone replacement attenuates the impairment of left ventricular (LV function and heart rate variability (HRV, and reduces the infarct size and arrhythmias caused by I/R injury in orchiectomized (ORX rats.ORX or sham-operated male Wistar rats (n = 24 were randomly divided and received either testosterone (2 mg/kg, subcutaneously administered or the vehicle for 8 weeks. The ejection fraction (EF and HRV were determined at baseline and the 4th and 8th week. I/R was performed by left anterior descending coronary artery ligation for 30 minutes, followed by a 120-minute reperfusion. LV pressure, arrhythmia scores, infarct size and cardiac mitochondrial function were determined.Prior to I/R, EF and HRV were impaired in the ORX group, but were restored in the testosterone-treated group. During I/R, arrhythmia scores and the infarct size were greater, and cardiac mitochondrial function was impaired, whereas the time to 1st VT/VF onset and the LV end-systolic pressure were decreased in the ORX group when compared to the sham group. Testosterone replacement attenuated the impairment of these parameters in ORX rats during I/R injury, but did not show any benefit or adverse effect in non-ORX rats.Testosterone replacement restores cardiac function and autonomic regulation, and exerts cardioprotective effects during the I/R period via mitochondrial protection in ORX rats.

  6. Pressure overload-induced mild cardiac hypertrophy reduces leftventricular transmural differences in mitochondrial respiratory chainactivity and increases oxidative stress

    Directory of Open Access Journals (Sweden)

    Michel eKINDO


    Full Text Available Objective: Increased mechanical stress and contractility characterizes normal left ventricular subendocardium (Endo but whether Endo mitochondrial respiratory chain complex activities is reduced as compared to subepicardium (Epi and whether pressure overload-induced left ventricular hypertrophy (LVH might modulate transmural gradients through increased reactive oxygen species (ROS production is unknown. Methods: LVH was induced by 6 weeks abdominal aortic banding and cardiac structure and function were determined with echocardiography and catheterization in sham-operated and LVH rats (n=10 for each group. Mitochondrial respiration rates, coupling, content and ROS production were measured in LV Endo and Epi, using saponin-permeabilised fibres, Amplex Red fluorescence and citrate synthase activity.Results: In sham, a transmural respiratory gradient was observed with decreases in endo maximal oxidative capacity (-36.7%, P<0.01 and complex IV activity (-57.4%, P<0.05. Mitochondrial hydrogen peroxide (H2O2 production was similar in both LV layers.Aortic banding induced mild LVH (+31.7% LV mass, associated with normal LV fractional shortening and end diastolic pressure. LVH reduced maximal oxidative capacity (-23.6 and -33.3%, increased mitochondrial H2O2 production (+86.9 and +73.1%, free radical leak (+27.2% and +36.3% and citrate synthase activity (+27.2% and +36.3% in Endo and Epi, respectively.Transmural mitochondrial respiratory chain complex IV activity was reduced in LVH (-57.4 vs –12.2%; P=0.02. Conclusions: Endo mitochondrial respiratory chain complexes activities are reduced compared to LV Epi. Mild LVH impairs mitochondrial oxidative capacity, increases oxidative stress and reduces transmural complex IV activity. Further studies will be helpful to determine whether reduced LV transmural gradient in mitochondrial respiration might be a new marker of a transition from uncomplicated toward complicated LVH.

  7. Dysfunctional cardiac mitochondrial bioenergetic, lipidomic, and signaling in a murine model of Barth syndrome. (United States)

    Kiebish, Michael A; Yang, Kui; Liu, Xinping; Mancuso, David J; Guan, Shaoping; Zhao, Zhongdan; Sims, Harold F; Cerqua, Rebekah; Cade, W Todd; Han, Xianlin; Gross, Richard W


    Barth syndrome is a complex metabolic disorder caused by mutations in the mitochondrial transacylase tafazzin. Recently, an inducible tafazzin shRNA knockdown mouse model was generated to deconvolute the complex bioenergetic phenotype of this disease. To investigate the underlying cause of hemodynamic dysfunction in Barth syndrome, we interrogated the cardiac structural and signaling lipidome of this mouse model as well as its myocardial bioenergetic phenotype. A decrease in the distribution of cardiolipin molecular species and robust increases in monolysocardiolipin and dilysocardiolipin were demonstrated. Additionally, the contents of choline and ethanolamine glycerophospholipid molecular species containing precursors for lipid signaling at the sn-2 position were altered. Lipidomic analyses revealed specific dysregulation of HETEs and prostanoids, as well as oxidized linoleic and docosahexaenoic metabolites. Bioenergetic interrogation uncovered differential substrate utilization as well as decreases in Complex III and V activities. Transgenic expression of cardiolipin synthase or iPLA2γ ablation in tafazzin-deficient mice did not rescue the observed phenotype. These results underscore the complex nature of alterations in cardiolipin metabolism mediated by tafazzin loss of function. Collectively, we identified specific lipidomic, bioenergetic, and signaling alterations in a murine model that parallel those of Barth syndrome thereby providing novel insights into the pathophysiology of this debilitating disease.

  8. Mitochondrial Myopathies (United States)

    ... which stimulates normal beating of the heart. Cardiac muscle damage also may occur. People with mitochondrial disorders may need to have regular examina- tions by a cardiologist. Other potential health issues Some people with mitochondrial disease experience ...

  9. Strained Compromises?

    DEFF Research Database (Denmark)

    Ibsen, Christian Lyhne

    The Danish version of flexicurity is not only about a balance between labour market flexibility and social security. Arguably, it is also series of more or less stable underlying compromises between social partners about the main mechanisms and aims of labour market regulation which – supposedly...... – should be focused on employment rather than jobs and competition on quality rather than on labour costs. However, most studies on Danish flexicurity have been carried out under favourable economic conditions with social partners almost naturally agreeing to the merits of the model – at least in principle...... underlines the dangers of building models based on short periods of stability....

  10. Receptor-interacting protein 140 overexpression impairs cardiac mitochondrial function and accelerates the transition to heart failure in chronically infarcted rats. (United States)

    Chen, YanFang; Chen, ShaoRui; Yue, ZhongBao; Zhang, YiQiang; Zhou, ChangHua; Cao, WeiWei; Chen, Xi; Zhang, LuanKun; Liu, PeiQing


    Heart failure (HF) is associated with myocardial energy metabolic abnormality. Receptor-interacting protein 140 (RIP140) is an important transcriptional cofactor for maintaining energy balance in high-oxygen consumption tissues. However, the role of RIP140 in the pathologic processes of HF remains to be elucidated. In this study, we investigated the role of RIP140 in mitochondrial and cardiac functions in rodent hearts under myocardial infarction (MI) stress. MI was created by a permanent ligation of left anterior descending coronary artery and exogenous expression of RIP140 by adenovirus (Ad) vector delivery. Four weeks after MI or Ad-RIP140 treatment, cardiac function was assessed by echocardiographic and hemodynamics analyses, and the mitochondrial function was determined by mitochondrial genes expression, biogenesis, and respiration rates. In Ad-RIP140 or MI group, a subset of metabolic genes changed, accompanied with slight reductions in mitochondrial biogenesis and respiration rates but no change in adenosine triphosphate (ATP) content. Cardiac malfunction was compensated. However, under MI stress, rats overexpressing RIP140 exhibited greater repressions in mitochondrial genes, state 3 respiration rates, respiration control ratio, and ATP content and had further deteriorated cardiac malfunction. In conclusion, RIP140 overexpression leads to comparable cardiac function as resulted from MI, but RIP140 aggravates metabolic repression, mitochondrial malfunction, and further accelerates the transition to HF in response to MI stress.

  11. Increased mitochondrial emission of reactive oxygen species and calpain activation are required for doxorubicin-induced cardiac and skeletal muscle myopathy. (United States)

    Min, Kisuk; Kwon, Oh-Sung; Smuder, Ashley J; Wiggs, Michael P; Sollanek, Kurt J; Christou, Demetra D; Yoo, Jeung-Ki; Hwang, Moon-Hyon; Szeto, Hazel H; Kavazis, Andreas N; Powers, Scott K


    Although doxorubicin (DOX) is a highly effective anti-tumour agent used to treat a variety of cancers, DOX administration is associated with significant side effects, including myopathy of both cardiac and skeletal muscles. The mechanisms responsible for DOX-mediated myopathy remain a topic of debate. We tested the hypothesis that both increased mitochondrial reactive oxygen species (ROS) emission and activation of the cysteine protease calpain are required for DOX-induced myopathy in rat cardiac and skeletal muscle. Cause and effect was determined by administering a novel mitochondrial-targeted anti-oxidant to prevent DOX-induced increases in mitochondrial ROS emission, whereas a highly-selective pharmacological inhibitor was exploited to inhibit calpain activity. Our findings reveal that mitochondria are a major site of DOX-mediated ROS production in both cardiac and skeletal muscle fibres and the prevention of DOX-induced increases in mitochondrial ROS emission protects against fibre atrophy and contractile dysfunction in both cardiac and skeletal muscles. Furthermore, our results indicate that DOX-induced increases in mitochondrial ROS emission are required to activate calpain in heart and skeletal muscles and, importantly, calpain activation is a major contributor to DOX-induced myopathy. Taken together, these findings show that increased mitochondrial ROS production and calpain activation are significant contributors to the development of DOX-induced myopathy in both cardiac and skeletal muscle fibres.

  12. Tissue-specific and substrate-specific mitochondrial bioenergetics in feline cardiac and skeletal muscles

    DEFF Research Database (Denmark)

    Christiansen, Liselotte Bruun; Dela, Flemming; Koch, Jørgen;


    No studies have investigated the mitochondrial function in permeabilized muscle fiber from cats. The aim of this study was to investigate tissue-specific and substrate-specific characteristics of mitochondrial oxidative phosphorylation (OXPHOS) capacity in feline permeabilized oxidative muscle...

  13. Doxorubicin-induced thiol-dependent alteration of cardiac mitochondrial permeability transition and respiration


    P. De Oliveira; Santos,M.; Wallace, K


    Abstract Doxorubicin (DOX) is a highly effective treatment for several forms of cancer. However, clinical experience shows that DOX induces a cumulative and dose-dependent cardiomyopathy that has been ascribed to redox-cycling of the drug on the mitochondrial respiratory chain generating free radicals and oxidative stress in the process. Mitochondrial dysfunction including induction of the mitochondrial permeability transition (MPT) and inhibition of mitochondrial respiration have been impli...

  14. Resveratrol Co-Treatment Attenuates the Effects of HIV Protease Inhibitors on Rat Body Weight and Enhances Cardiac Mitochondrial Respiration (United States)

    Symington, Burger; Mapanga, Rudo F.; Norton, Gavin R.


    Since the early 1990s human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) emerged as a global health pandemic, with sub-Saharan Africa the hardest hit. While the successful roll-out of antiretroviral (ARV) therapy provided significant relief to HIV-positive individuals, such treatment can also elicit damaging side-effects. Here especially HIV protease inhibitors (PIs) are implicated in the onset of cardio-metabolic complications such as type-2 diabetes and coronary heart disease. As there is a paucity of data regarding suitable co-treatments within this context, this preclinical study investigated whether resveratrol (RSV), aspirin (ASP) or vitamin C (VitC) co-treatment is able to blunt side-effects in a rat model of chronic PI exposure (Lopinavir/Ritonavir treatment for 4 months). Body weights and weight gain, blood metabolite levels (total cholesterol, HDL, LDL, triglycerides), echocardiography and cardiac mitochondrial respiration were assessed in PI-treated rats ± various co-treatments. Our data reveal that PI treatment significantly lowered body weight and cardiac respiratory function while no significant changes were found for heart function and blood metabolite levels. Moreover, all co-treatments ameliorated the PI-induced decrease in body weight after 4 months of PI treatment, while RSV co-treatment enhanced cardiac mitochondrial respiratory capacity in PI-treated rats. This pilot study therefore provides novel hypotheses regarding RSV co-treatment that should be further assessed in greater detail. PMID:28107484

  15. Dietary saturated fat and docosahexaenoic acid differentially effect cardiac mitochondrial phospholipid fatty acyl composition and Ca(2+) uptake, without altering permeability transition or left ventricular function. (United States)

    O'Connell, Kelly A; Dabkowski, Erinne R; de Fatima Galvao, Tatiana; Xu, Wenhong; Daneault, Caroline; de Rosiers, Christine; Stanley, William C


    High saturated fat diets improve cardiac function and survival in rodent models of heart failure, which may be mediated by changes in mitochondrial function. Dietary supplementation with the n3-polyunsaturated fatty acid docosahexaenoic acid (DHA, 22:6n3) is also beneficial in heart failure and can affect mitochondrial function. Saturated fatty acids and DHA likely have opposing effects on mitochondrial phospholipid fatty acyl side chain composition and mitochondrial membrane function, though a direct comparison has not been previously reported. We fed healthy adult rats a standard low-fat diet (11% of energy intake from fat), a low-fat diet supplemented with DHA (2.3% of energy intake) or a high-fat diet comprised of long chain saturated fatty acids (45% fat) for 6 weeks. There were no differences among the three diets in cardiac mass or function, mitochondrial respiration, or Ca(2+)-induced mitochondrial permeability transition. On the other hand, there were dramatic differences in mitochondrial phospholipid fatty acyl side chains. Dietary supplementation with DHA increased DHA from 7% to ∼25% of total phospholipid fatty acids in mitochondrial membranes, and caused a proportional depletion of arachidonic acid (20:4n6). The saturated fat diet increased saturated fat and DHA in mitochondria and decreased linoleate (18:2n6), which corresponded to a decrease in Ca(2+) uptake by isolated mitochondria compared to the other diet groups. In conclusion, despite dramatic changes in mitochondrial phospholipid fatty acyl side chain composition by both the DHA and high saturated fat diets, there were no effects on mitochondrial respiration, permeability transition, or cardiac function.

  16. Cardiac structure and function during ageing in energetically compromised Guanidinoacetate N-methyltransferase (GAMT-knockout mice – a one year longitudinal MRI study

    Directory of Open Access Journals (Sweden)

    Clarke Kieran


    Full Text Available Abstract Background High-resolution magnetic resonance imaging (cine-MRI is well suited for determining global cardiac function longitudinally in genetically or surgically manipulated mice, but in practice it is seldom used to its full potential. In this study, male and female guanidinoacetate N-methyltransferase (GAMT knockout, and wild type littermate mice were subjected to a longitudinal cine-MRI study at four time points over the course of one year. GAMT is an essential enzyme in creatine biosynthesis, such that GAMT deficient mice are entirely creatine-free. Since creatine plays an important role in the buffering and transfer of high-energy phosphate bonds in the heart, it was hypothesized that lack of creatine would be detrimental for resting cardiac performance during ageing. Methods Measurements of cardiac structure (left ventricular mass and volumes and function (ejection fraction, stroke volume, cardiac output were obtained using high-resolution cine-MRI at 9.4 T under isoflurane anaesthesia. Results There were no physiologically significant differences in cardiac function between wild type and GAMT knockout mice at any time point for male or female groups, or for both combined (for example ejection fraction: 6 weeks (KO vs. WT: 70 ± 6% vs. 65 ± 7%; 4 months: 70 ± 6% vs. 62 ± 8%; 8 months: 62 ± 11% vs. 62 ± 6%; 12 months: 61 ± 7% vs. 59 ± 11%, respectively. Conclusion These findings suggest the presence of comprehensive adaptations in the knockout mice that can compensate for a lack of creatine. Furthermore, this study clearly demonstrates the power of cine-MRI for accurate non-invasive, serial cardiac measurements. Cardiac growth curves could easily be defined for each group, in the same set of animals for all time points, providing improved statistical power, and substantially reducing the number of mice required to conduct such a study. This technique should be eminently useful for following changes of cardiac structure and

  17. Cardiac abnormalities in diabetic patients with mutation in the mitochondrial tRNA {sup Leu(UUR)}Gene

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, Hiroshi [Hyogo Medical Center for Adults, Akashi (Japan); Shiotani, Hideyuki


    An A-to-G transition at position 3243 of the mitochondrial DNA is known to be a pathogenic factor for mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS), diabetes and cardiomyopathy. This mutation causes dysfunction of the central nervous system in MELAS. Because the heart, as well as the brain and nervous system, is highly dependent on the energy produced by mitochondrial oxidation, these tissues are more vulnerable to mitochondrial defects. Cardiac abnormalities were assessed in 10 diabetic patients associated with this mutation using echocardiography and {sup 123}I-metaiodobenzylguanidine (MIBG) scintigraphy, and compared with 19 diabetic patients without the mutation. Duration of diabetes, therapy, control of blood glucose and diabetic complications, such as diabetic retinopathy and nephropathy, were not different between the 2 groups. Diabetic patients with the mutation had a significantly thicker interventricular septum (16.8{+-}3.7 vs 11.0{+-}1.6 mm, p<0.001) than those without the mutation. Fractional shortening was lower in diabetic patients with the mutation than those without it (30.7{+-}7.0 vs 42.5{+-}6.6, p<0.001). MIBG uptake on the delayed MIBG image was significantly lower in diabetic patients with the mutation than in those without the mutation (mean value of the heart to mediastinum ratio: 1.6{+-}0.2 vs 2.0{+-}0.4, p>0.05). In conclusion, left ventricular hypertrophy with or without abnormal wall motion and severely reduced MIBG uptake may be characteristic in diabetic patients with a mutation in the mitochondrial tRNA {sup Leu(UUR)} gene. (author)

  18. Poly(GR) in C9ORF72-Related ALS/FTD Compromises Mitochondrial Function and Increases Oxidative Stress and DNA Damage in iPSC-Derived Motor Neurons. (United States)

    Lopez-Gonzalez, Rodrigo; Lu, Yubing; Gendron, Tania F; Karydas, Anna; Tran, Helene; Yang, Dejun; Petrucelli, Leonard; Miller, Bruce L; Almeida, Sandra; Gao, Fen-Biao


    GGGGCC repeat expansions in C9ORF72 are the most common genetic cause of both ALS and FTD. To uncover underlying pathogenic mechanisms, we found that DNA damage was greater, in an age-dependent manner, in motor neurons differentiated from iPSCs of multiple C9ORF72 patients than control neurons. Ectopic expression of the dipeptide repeat (DPR) protein (GR)80 in iPSC-derived control neurons increased DNA damage, suggesting poly(GR) contributes to DNA damage in aged C9ORF72 neurons. Oxidative stress was also increased in C9ORF72 neurons in an age-dependent manner. Pharmacological or genetic reduction of oxidative stress partially rescued DNA damage in C9ORF72 neurons and control neurons expressing (GR)80 or (GR)80-induced cellular toxicity in flies. Moreover, interactome analysis revealed that (GR)80 preferentially bound to mitochondrial ribosomal proteins and caused mitochondrial dysfunction. Thus, poly(GR) in C9ORF72 neurons compromises mitochondrial function and causes DNA damage in part by increasing oxidative stress, revealing another pathogenic mechanism in C9ORF72-related ALS and FTD.

  19. Decreased hydrogen peroxide production and mitochondrial respiration in skeletal muscle but not cardiac muscle of the green-striped burrowing frog, a natural model of muscle disuse. (United States)

    Reilly, Beau D; Hickey, Anthony J R; Cramp, Rebecca L; Franklin, Craig E


    Suppression of disuse-induced muscle atrophy has been associated with altered mitochondrial reactive oxygen species (ROS) production in mammals. However, despite extended hindlimb immobility, aestivating animals exhibit little skeletal muscle atrophy compared with artificially immobilised mammalian models. Therefore, we studied mitochondrial respiration and ROS (H2O2) production in permeabilised muscle fibres of the green-striped burrowing frog, Cyclorana alboguttata. Mitochondrial respiration within saponin-permeabilised skeletal and cardiac muscle fibres was measured concurrently with ROS production using high-resolution respirometry coupled to custom-made fluorometers. After 4 months of aestivation, C. alboguttata had significantly depressed whole-body metabolism by ~70% relative to control (active) frogs, and mitochondrial respiration in saponin-permeabilised skeletal muscle fibres decreased by almost 50% both in the absence of ADP and during oxidative phosphorylation. Mitochondrial ROS production showed up to an 88% depression in aestivating skeletal muscle when malate, succinate and pyruvate were present at concentrations likely to reflect those in vivo. The percentage ROS released per O2 molecule consumed was also ~94% less at these concentrations, indicating an intrinsic difference in ROS production capacities during aestivation. We also examined mitochondrial respiration and ROS production in permeabilised cardiac muscle fibres and found that aestivating frogs maintained respiratory flux and ROS production at control levels. These results show that aestivating C. alboguttata has the capacity to independently regulate mitochondrial function in skeletal and cardiac muscles. Furthermore, this work indicates that ROS production can be suppressed in the disused skeletal muscle of aestivating frogs, which may in turn protect against potential oxidative damage and preserve skeletal muscle structure during aestivation and following arousal.

  20. Heart mitochondrial proteome study elucidates changes in cardiac energy metabolism and antioxidant PRDX3 in human dilated cardiomyopathy.

    Directory of Open Access Journals (Sweden)

    Esther Roselló-Lletí

    Full Text Available Dilated cardiomyopathy (DCM is a public health problem with no available curative treatment, and mitochondrial dysfunction plays a critical role in its development. The present study is the first to analyze the mitochondrial proteome in cardiac tissue of patients with DCM to identify potential molecular targets for its therapeutic intervention.16 left ventricular (LV samples obtained from explanted human hearts with DCM (n = 8 and control donors (n = 8 were extracted to perform a proteomic approach to investigate the variations in mitochondrial protein expression. The proteome of the samples was analyzed by quantitative differential electrophoresis and Mass Spectrometry. These changes were validated by classical techniques and by novel and precise selected reaction monitoring analysis and RNA sequencing approach increasing the total heart samples up to 25. We found significant alterations in energy metabolism, especially in molecules involved in substrate utilization (ODPA, ETFD, DLDH, energy production (ATPA, other metabolic pathways (AL4A1 and protein synthesis (EFTU, obtaining considerable and specific relationships between the alterations detected in these processes. Importantly, we observed that the antioxidant PRDX3 overexpression is associated with impaired ventricular function. PRDX3 is significantly related to LV end systolic and diastolic diameter (r = 0.73, p value<0.01; r = 0.71, p value<0.01, fractional shortening, and ejection fraction (r = -0.61, p value<0.05; and r = -0.62, p value<0.05, respectively.This work could be a pivotal study to gain more knowledge on the cellular mechanisms related to the pathophysiology of this disease and may lead to the development of etiology-specific heart failure therapies. We suggest new molecular targets for therapeutic interventions, something that up to now has been lacking.

  1. Ablation of PGC-1 beta results in defective mitochondrial activity, thermogenesis, hepatic function, and cardiac performance


    Lelliott, Christopher J.; Gema Medina-Gomez; Natasa Petrovic; Adrienn Kis; Feldmann, Helena M; Mikael Bjursell; Nadeene Parker; Keira Curtis; Mark Campbell; Ping Hu; Dongfang Zhang; Litwin, Sheldon E.; Vlad G Zaha; Fountain, Kimberly T; Sihem Boudina


    International audience; The transcriptional coactivator peroxisome proliferator-activated receptor-gamma coactivator-1beta (PGC-1beta) has been implicated in important metabolic processes. A mouse lacking PGC-1beta (PGC1betaKO) was generated and phenotyped using physiological, molecular, and bioinformatic approaches. PGC1betaKO mice are generally viable and metabolically healthy. Using systems biology, we identified a general defect in the expression of genes involved in mitochondrial functio...

  2. Ablation of PGC-1beta results in defective mitochondrial activity, thermogenesis, hepatic function, and cardiac performance.

    Directory of Open Access Journals (Sweden)

    Christopher J Lelliott


    Full Text Available The transcriptional coactivator peroxisome proliferator-activated receptor-gamma coactivator-1beta (PGC-1beta has been implicated in important metabolic processes. A mouse lacking PGC-1beta (PGC1betaKO was generated and phenotyped using physiological, molecular, and bioinformatic approaches. PGC1betaKO mice are generally viable and metabolically healthy. Using systems biology, we identified a general defect in the expression of genes involved in mitochondrial function and, specifically, the electron transport chain. This defect correlated with reduced mitochondrial volume fraction in soleus muscle and heart, but not brown adipose tissue (BAT. Under ambient temperature conditions, PGC-1beta ablation was partially compensated by up-regulation of PGC-1alpha in BAT and white adipose tissue (WAT that lead to increased thermogenesis, reduced body weight, and reduced fat mass. Despite their decreased fat mass, PGC1betaKO mice had hypertrophic adipocytes in WAT. The thermogenic role of PGC-1beta was identified in thermoneutral and cold-adapted conditions by inadequate responses to norepinephrine injection. Furthermore, PGC1betaKO hearts showed a blunted chronotropic response to dobutamine stimulation, and isolated soleus muscle fibres from PGC1betaKO mice have impaired mitochondrial function. Lack of PGC-1beta also impaired hepatic lipid metabolism in response to acute high fat dietary loads, resulting in hepatic steatosis and reduced lipoprotein-associated triglyceride and cholesterol content. Altogether, our data suggest that PGC-1beta plays a general role in controlling basal mitochondrial function and also participates in tissue-specific adaptive responses during metabolic stress.

  3. High expression of nuclear factor 90 (NF90 leads to mitochondrial degradation in skeletal and cardiac muscles.

    Directory of Open Access Journals (Sweden)

    Takuma Higuchi

    Full Text Available While NF90 has been known to participate in transcription, translation and microRNA biogenesis, physiological functions of this protein still remain unclear. To uncover this, we generated transgenic (Tg mice using NF90 cDNA under the control of β-actin promoter. The NF90 Tg mice exhibited a reduction in body weight compared with wild-type mice, and a robust expression of NF90 was detected in skeletal muscle, heart and eye of the Tg mice. To evaluate the NF90 overexpression-induced physiological changes in the tissues, we performed a number of analyses including CT-analysis and hemodynamic test, revealing that the NF90 Tg mice developed skeletal muscular atrophy and heart failure. To explore causes of the abnormalities in the NF90 Tg mice, we performed histological and biochemical analyses for the skeletal and cardiac muscles of the Tg mice. Surprisingly, these analyses demonstrated that mitochondria in those muscular tissues of the Tg mice were degenerated by autophagy. To gain further insight into the cause for the mitochondrial degeneration, we identified NF90-associated factors by peptide mass fingerprinting. Of note, approximately half of the NF90-associated complexes were ribosome-related proteins. Interestingly, protein synthesis rate was significantly suppressed by high-expression of NF90. These observations suggest that NF90 would negatively regulate the function of ribosome via its interaction with the factors involved in the ribosome function. Furthermore, we found that the translations or protein stabilities of PGC-1 and NRF-1, which are critical transcription factors for expression of mitochondrial genes, were significantly depressed in the skeletal muscles of the NF90 Tg mice. Taken together, these findings suggest that the mitochondrial degeneration engaged in the skeletal muscle atrophy and the heart failure in the NF90 Tg mice may be caused by NF90-induced posttranscriptional repression of transcription factors such as PGC-1 and

  4. Mg(2+) differentially regulates two modes of mitochondrial Ca(2+) uptake in isolated cardiac mitochondria: implications for mitochondrial Ca(2+) sequestration. (United States)

    Blomeyer, Christoph A; Bazil, Jason N; Stowe, David F; Dash, Ranjan K; Camara, Amadou K S


    The manner in which mitochondria take up and store Ca(2+) remains highly debated. Recent experimental and computational evidence has suggested the presence of at least two modes of Ca(2+) uptake and a complex Ca(2+) sequestration mechanism in mitochondria. But how Mg(2+) regulates these different modes of Ca(2+) uptake as well as mitochondrial Ca(2+) sequestration is not known. In this study, we investigated two different ways by which mitochondria take up and sequester Ca(2+) by using two different protocols. Isolated guinea pig cardiac mitochondria were exposed to varying concentrations of CaCl2 in the presence or absence of MgCl2. In the first protocol, A, CaCl2 was added to the respiration buffer containing isolated mitochondria, whereas in the second protocol, B, mitochondria were added to the respiration buffer with CaCl2 already present. Protocol A resulted first in a fast transitory uptake followed by a slow gradual uptake. In contrast, protocol B only revealed a slow and gradual Ca(2+) uptake, which was approximately 40 % of the slow uptake rate observed in protocol A. These two types of Ca(2+) uptake modes were differentially modulated by extra-matrix Mg(2+). That is, Mg(2+) markedly inhibited the slow mode of Ca(2+) uptake in both protocols in a concentration-dependent manner, but not the fast mode of uptake exhibited in protocol A. Mg(2+) also inhibited Na(+)-dependent Ca(2+) extrusion. The general Ca(2+) binding properties of the mitochondrial Ca(2+) sequestration system were reaffirmed and shown to be independent of the mode of Ca(2+) uptake, i.e. through the fast or slow mode of uptake. In addition, extra-matrix Mg(2+) hindered Ca(2+) sequestration. Our results indicate that mitochondria exhibit different modes of Ca(2+) uptake depending on the nature of exposure to extra-matrix Ca(2+), which are differentially sensitive to Mg(2+). The implications of these findings in cardiomyocytes are discussed.

  5. Ceramide transfer protein deficiency compromises organelle function and leads to senescence in primary cells.

    Directory of Open Access Journals (Sweden)

    Raghavendra Pralhada Rao

    Full Text Available Ceramide transfer protein (CERT transfers ceramide from the endoplasmic reticulum (ER to the Golgi complex. Its deficiency in mouse leads to embryonic death at E11.5. CERT deficient embryos die from cardiac failure due to defective organogenesis, but not due to ceramide induced apoptotic or necrotic cell death. In the current study we examined the effect of CERT deficiency in a primary cell line, namely, mouse embryonic fibroblasts (MEFs. We show that in MEFs, unlike in mutant embryos, lack of CERT does not lead to increased ceramide but causes an accumulation of hexosylceramides. Nevertheless, the defects due to defective sphingolipid metabolism that ensue, when ceramide fails to be trafficked from ER to the Golgi complex, compromise the viability of the cell. Therefore, MEFs display an incipient ER stress. While we observe that ceramide trafficking from ER to the Golgi complex is compromised, the forward transport of VSVG-GFP protein is unhindered from ER to Golgi complex to the plasma membrane. However, retrograde trafficking of the plasma membrane-associated cholera toxin B to the Golgi complex is reduced. The dysregulated sphingolipid metabolism also leads to increased mitochondrial hexosylceramide. The mitochondrial functions are also compromised in mutant MEFs since they have reduced ATP levels, have increased reactive oxygen species, and show increased glutathione reductase activity. Live-cell imaging shows that the mutant mitochondria exhibit reduced fission and fusion events. The mitochondrial dysfunction leads to an increased mitophagy in the CERT mutant MEFs. The compromised organelle function compromise cell viability and results in premature senescence of these MEFs.

  6. The Responses of Tissues from the Brain, Heart, Kidney, and Liver to Resuscitation following Prolonged Cardiac Arrest by Examining Mitochondrial Respiration in Rats

    Directory of Open Access Journals (Sweden)

    Junhwan Kim


    Full Text Available Cardiac arrest induces whole-body ischemia, which causes damage to multiple organs. Understanding how each organ responds to ischemia/reperfusion is important to develop better resuscitation strategies. Because direct measurement of organ function is not practicable in most animal models, we attempt to use mitochondrial respiration to test efficacy of resuscitation on the brain, heart, kidney, and liver following prolonged cardiac arrest. Male Sprague-Dawley rats are subjected to asphyxia-induced cardiac arrest for 30 min or 45 min, or 30 min cardiac arrest followed by 60 min cardiopulmonary bypass resuscitation. Mitochondria are isolated from brain, heart, kidney, and liver tissues and examined for respiration activity. Following cardiac arrest, a time-dependent decrease in state-3 respiration is observed in mitochondria from all four tissues. Following 60 min resuscitation, the respiration activity of brain mitochondria varies greatly in different animals. The activity after resuscitation remains the same in heart mitochondria and significantly increases in kidney and liver mitochondria. The result shows that inhibition of state-3 respiration is a good marker to evaluate the efficacy of resuscitation for each organ. The resulting state-3 respiration of brain and heart mitochondria following resuscitation reenforces the need for developing better strategies to resuscitate these critical organs following prolonged cardiac arrest.

  7. The Responses of Tissues from the Brain, Heart, Kidney, and Liver to Resuscitation following Prolonged Cardiac Arrest by Examining Mitochondrial Respiration in Rats. (United States)

    Kim, Junhwan; Villarroel, José Paul Perales; Zhang, Wei; Yin, Tai; Shinozaki, Koichiro; Hong, Angela; Lampe, Joshua W; Becker, Lance B


    Cardiac arrest induces whole-body ischemia, which causes damage to multiple organs. Understanding how each organ responds to ischemia/reperfusion is important to develop better resuscitation strategies. Because direct measurement of organ function is not practicable in most animal models, we attempt to use mitochondrial respiration to test efficacy of resuscitation on the brain, heart, kidney, and liver following prolonged cardiac arrest. Male Sprague-Dawley rats are subjected to asphyxia-induced cardiac arrest for 30 min or 45 min, or 30 min cardiac arrest followed by 60 min cardiopulmonary bypass resuscitation. Mitochondria are isolated from brain, heart, kidney, and liver tissues and examined for respiration activity. Following cardiac arrest, a time-dependent decrease in state-3 respiration is observed in mitochondria from all four tissues. Following 60 min resuscitation, the respiration activity of brain mitochondria varies greatly in different animals. The activity after resuscitation remains the same in heart mitochondria and significantly increases in kidney and liver mitochondria. The result shows that inhibition of state-3 respiration is a good marker to evaluate the efficacy of resuscitation for each organ. The resulting state-3 respiration of brain and heart mitochondria following resuscitation reenforces the need for developing better strategies to resuscitate these critical organs following prolonged cardiac arrest.

  8. Cardiac-Specific Knockout of ETA Receptor Mitigates Paraquat-Induced Cardiac Contractile Dysfunction. (United States)

    Wang, Jiaxing; Lu, Songhe; Zheng, Qijun; Hu, Nan; Yu, Wenjun; Li, Na; Liu, Min; Gao, Beilei; Zhang, Guoyong; Zhang, Yingmei; Wang, Haichang


    Paraquat (1,1'-dim ethyl-4-4'-bipyridinium dichloride), a highly toxic quaternary ammonium herbicide widely used in agriculture, exerts potent toxic prooxidant effects resulting in multi-organ failure including the lung and heart although the underlying mechanism remains elusive. Recent evidence suggests possible involvement of endothelin system in paraquat-induced acute lung injury. This study was designed to examine the role of endothelin receptor A (ETA) in paraquat-induced cardiac contractile and mitochondrial injury. Wild-type (WT) and cardiac-specific ETA receptor knockout mice were challenged to paraquat (45 mg/kg, i.p.) for 48 h prior to the assessment of echocardiographic, cardiomyocyte contractile and intracellular Ca(2+) properties, as well as apoptosis and mitochondrial damage. Levels of the mitochondrial proteins for biogenesis and oxidative phosphorylation including UCP2, HSP90 and PGC1α were evaluated. Our results revealed that paraquat elicited cardiac enlargement, mechanical anomalies including compromised echocardiographic parameters (elevated left ventricular end-systolic and end-diastolic diameters as well as reduced factional shortening), suppressed cardiomyocyte contractile function, intracellular Ca(2+) handling, overt apoptosis and mitochondrial damage. ETA receptor knockout itself failed to affect myocardial function, apoptosis, mitochondrial integrity and mitochondrial protein expression. However, ETA receptor knockout ablated or significantly attenuated paraquat-induced cardiac contractile and intracellular Ca(2+) defect, apoptosis and mitochondrial damage. Taken together, these findings revealed that endothelin system in particular the ETA receptor may be involved in paraquat-induced toxic myocardial contractile anomalies possibly related to apoptosis and mitochondrial damage.

  9. Compromise and Toleration

    DEFF Research Database (Denmark)

    Rostbøll, Christian F.

    Political compromise is akin to toleration, since both consist of an "agreement to disagree." Compromise and toleration also share a predicament of being regarded as ambiguous virtues that require of us to accept something we actually regard as wrong. However, we misunderstand the nature......, justification, and limits of compromise if we see it merely as a matter of toleration. While toleration is mainly a matter of accepting citizens' equal right to co-existence as subjects to law, political compromise includes the parties in making law – it makes them co-authors of law. Toleration entails...... respecting the plurality of conceptions of the good in society, whereas political compromise embodies the disagreements in coercive laws. This difference between toleration and compromise has two important consequences. First, political compromise is justified in a different manner than is toleration...

  10. Increased in vivo mitochondrial oxygenation with right ventricular failure induced by pulmonary arterial hypertension: Mitochondrial inhibition as driver of cardiac failure?

    NARCIS (Netherlands)

    G.M. Balestra (Gianmarco); E.G. Mik (Egbert); O. Eerbeek (Otto); P. Specht (Patricia); W.J. van der Laarse (Willem J.); C.J. Zuurbier (Coert J.)


    textabstractBackground: The leading cause of mortality due to pulmonary arterial hypertension (PAH) is failure of the cardiac right ventricle. It has long been hypothesized that during the development of chronic cardiac failure the heart becomes energy deprived, possibly due to shortage of oxygen at

  11. Angiotensin receptor-mediated oxidative stress is associated with impaired cardiac redox signaling and mitochondrial function in insulin-resistant rats. (United States)

    Vázquez-Medina, José Pablo; Popovich, Irina; Thorwald, Max A; Viscarra, Jose A; Rodriguez, Ruben; Sonanez-Organis, Jose G; Lam, Lisa; Peti-Peterdi, Janos; Nakano, Daisuke; Nishiyama, Akira; Ortiz, Rudy M


    Activation of angiotensin receptor type 1 (AT1) contributes to NADPH oxidase (Nox)-derived oxidative stress during metabolic syndrome. However, the specific role of AT1 in modulating redox signaling, mitochondrial function, and oxidative stress in the heart remains more elusive. To test the hypothesis that AT1 activation increases oxidative stress while impairing redox signaling and mitochondrial function in the heart during diet-induced insulin resistance in obese animals, Otsuka Long Evans Tokushima Fatty (OLETF) rats (n = 8/group) were treated with the AT1 blocker (ARB) olmesartan for 6 wk. Cardiac Nox2 protein expression increased 40% in OLETF compared with age-matched, lean, strain-control Long Evans Tokushima Otsuka (LETO) rats, while mRNA and protein expression of the H₂O₂-producing Nox4 increased 40-100%. ARB treatment prevented the increase in Nox2 without altering Nox4. ARB treatment also normalized the increased levels of protein and lipid oxidation (nitrotyrosine, 4-hydroxynonenal) and increased the redox-sensitive transcription factor Nrf2 by 30% and the activity of antioxidant enzymes (SOD, catalase, GPx) by 50-70%. Citrate synthase (CS) and succinate dehydrogenase (SDH) activities decreased 60-70%, whereas cardiac succinate levels decreased 35% in OLETF compared with LETO, suggesting that mitochondrial function in the heart is impaired during obesity-induced insulin resistance. ARB treatment normalized CS and SDH activities, as well as succinate levels, while increasing AMPK and normalizing Akt, suggesting that AT1 activation also impairs cellular metabolism in the diabetic heart. These data suggest that the cardiovascular complications associated with metabolic syndrome may result from AT1 receptor-mediated Nox2 activation leading to impaired redox signaling, mitochondrial activity, and dysregulation of cellular metabolism in the heart.

  12. A cardiac-specific robotized cellular assay identified families of human ligands as inducers of PGC-1α expression and mitochondrial biogenesis.

    Directory of Open Access Journals (Sweden)

    Matthieu Ruiz

    Full Text Available BACKGROUND: Mitochondrial function is dramatically altered in heart failure (HF. This is associated with a decrease in the expression of the transcriptional coactivator PGC-1α, which plays a key role in the coordination of energy metabolism. Identification of compounds able to activate PGC-1α transcription could be of future therapeutic significance. METHODOLOGY/PRINCIPAL FINDINGS: We thus developed a robotized cellular assay to screen molecules in order to identify new activators of PGC-1α in a cardiac-like cell line. This screening assay was based on both the assessment of activity and gene expression of a secreted luciferase under the control of the human PGC-1α promoter, stably expressed in H9c2 cells. We screened part of a library of human endogenous ligands and steroid hormones, B vitamins and fatty acids were identified as activators of PGC-1α expression. The most responsive compounds of these families were then tested for PGC-1α gene expression in adult rat cardiomyocytes. These data highly confirmed the primary screening, and the increase in PGC-1α mRNA correlated with an increase in several downstream markers of mitochondrial biogenesis. Moreover, respiration rates of H9c2 cells treated with these compounds were increased evidencing their effectiveness on mitochondrial biogenesis. CONCLUSIONS/SIGNIFICANCE: Using our cellular reporter assay we could identify three original families, able to activate mitochondrial biogenesis both in cell line and adult cardiomyocytes. This first screening can be extended to chemical libraries in order to increase our knowledge on PGC-1α regulation in the heart and to identify potential therapeutic compounds able to improve mitochondrial function in HF.

  13. Mitochondrial basis of the anti-arrhythmic action of lidocaine and modulation by the n-6 to n-3 PUFA ratio of cardiac phospholipids. (United States)

    Demaison, Luc; Moreau, Daniel; Clauw, Fabienne; Vergely, Catherine; Rochette, Luc


    The aim of this study was to evaluate the involvement of mitochondria in the mechanism of the anti-arrhythmic lidocaine. Rats were fed with a diet containing either n-6 polyunsaturated fatty acids (PUFAs, SSO group) or an equimolecular mixture of n-3 and n-6 PUFAs (FO group) for 8 weeks. The hearts were perfused according to the working mode using a medium with or without lidocaine 5 μm. They were then subjected to local ischemia (20 min) and reperfusion (30 min). Dietary n-3 PUFAs triggered the expected decrease in the n-6/n-3 PUFA ratio of cardiac phospholipids. Reperfusing the ischemic area favored the incidence of severe arrhythmias. Lidocaine treatment abolished almost completely reperfusion arrhythmias in the FO group, but did not display anti-arrhythmic properties in the SSO group. As it was indicated by measurements of the mitochondrial function, lidocaine seemed to favor mitochondrial calcium retention in the FO group, which might prevent cytosolic calcium spikes and reperfusion arrhythmias. In the SSO group, the resistance to lidocaine was associated with an aggravation of cellular damages. The mitochondrial calcium retention capacities were saturated, and lidocaine was unable to increase them, making the drug inefficient in preventing reperfusion arrhythmias.

  14. Neonatal multiorgan failure due to ACAD9 mutation and complex I deficiency with mitochondrial hyperplasia in liver, cardiac myocytes, skeletal muscle, and renal tubules. (United States)

    Leslie, Nancy; Wang, Xinjian; Peng, Yanyan; Valencia, C Alexander; Khuchua, Zaza; Hata, Jessica; Witte, David; Huang, Taosheng; Bove, Kevin E


    Complex I deficiency causes Leigh syndrome, fatal infant lactic acidosis, and neonatal cardiomyopathy. Mutations in more than 100 nuclear DNA and mitochondrial DNA genes miscode for complex I subunits or assembly factors. ACAD9 is an acyl-CoA dehydrogenase with a novel function in assembly of complex I; biallelic mutations cause progressive encephalomyopathy, recurrent Reye syndrome, and fatal cardiomyopathy. We describe the first autopsy in fatal neonatal lethal lactic acidosis due to mutations in ACAD9 that reduced complex I activity. We identified mitochondrial hyperplasia in cardiac myocytes, diaphragm muscle, and liver and renal tubules in formalin-fixed, paraffin-embedded tissue using immunohistochemistry for mitochondrial antigens. Whole-exome sequencing revealed compound heterozygous variants in the ACAD9 gene: c.187G>T (p.E63*) and c.941T>C (p.L314P). The nonsense mutation causes late infantile lethality; the missense variant is novel. Autopsy-derived fibroblasts had reduced complex I activity (53% of control) with normal activity in complexes II to IV, similar to reported cases of ACAD9 deficiency.

  15. Compromises of Bali Roadmap

    Institute of Scientific and Technical Information of China (English)

    Wang Jingmin; Wei Dong


    The Bali Roadmap, as the breakthrough on intergovernmental negotiation of climate change mitigation, having brought United States on track, is still a result of compromises. The major compromises of the Bali Roadmap are centered around three issues of quantifying emission reduction targets, developing countries' obligations as well as quantifying developed countries' financial assistance in developing countries' capacity building on climate change. It is found that the rationalities behind these compromises are the national interests. Due to the fact, achieving cohesion among all nations in climate change actions is very difficult. Therefore, the Bali Roadmap may lead to a tough way with distant hope. However, technology innovation and well-designed economic instruments would be helpful and supportive for further international negotiation and cooperation.

  16. Protective Effect of Sevoflurane Postconditioning against Cardiac Ischemia/Reperfusion Injury via Ameliorating Mitochondrial Impairment, Oxidative Stress and Rescuing Autophagic Clearance.

    Directory of Open Access Journals (Sweden)

    Peng Yu

    Full Text Available Myocardial infarction leads to heart failure. Autophagy is excessively activated in myocardial ischemia/reperfusion (I/R in rats. The aim of this study is to investigate whether the protection of sevoflurane postconditioning (SPC in myocardial I/R is through restored impaired autophagic flux.Except for the sham control (SHAM group, each rat underwent 30 min occlusion of the left anterior descending coronary (LAD followed by 2 h reperfusion. Cardiac infarction was determined by 2,3,5-triphenyltetrazolium chloride triazole (TTC staining. Cardiac function was examined by hemodynamics and echocardiography. The activation of autophagy was evaluated by autophagosome accumulation, LC3 conversion and p62 degradation. Potential molecular mechanisms were investigated by immunoblotting, real-time PCR and immunofluorescence staining.SPC improved the hemodynamic parameters, cardiac dysfunction, histopathological and ultrastructural damages, and decreased myocardial infarction size after myocardial I/R injury (P < 0.05 vs. I/R group. Compared with the cases in I/R group, myocardial ATP and NAD+ content, mitochondrial function related genes and proteins, and the expressions of SOD2 and HO-1 were increased, while the expressions of ROS and Vimentin were decreased in the SPC group (P < 0.05 vs. I/R group. SPC significantly activated Akt/mTOR signaling, and inhibited the formation of Vps34/Beclin1 complex via increasing expression of Bcl2 protein (P < 0.05 vs. I/R group. SPC suppressed elevated expressions of LC3 II/I ratio, Beclin1, Atg5 and Atg7 in I/R rat, which indicated that SPC inhibited over-activation of autophagy, and promoted autophagosome clearance. Meanwhile, SPC significantly suppressed the decline of Opa1 and increases of Drp1 and Parkin induced by I/R injury (P < 0.05 vs. I/R group. Moreover, SPC maintained the contents of ATP by reducing impaired mitochondria.SPC protects rat hearts against I/R injury via ameliorating mitochondrial impairment

  17. A novel protective mechanism for mitochondrial aldehyde dehydrogenase (ALDH2) in type i diabetes-induced cardiac dysfunction: role of AMPK-regulated autophagy. (United States)

    Guo, Yuli; Yu, Wenjun; Sun, Dongdong; Wang, Jiaxing; Li, Congye; Zhang, Rongqing; Babcock, Sara A; Li, Yan; Liu, Min; Ma, Meijuan; Shen, Mingzhi; Zeng, Chao; Li, Na; He, Wei; Zou, Qian; Zhang, Yingmei; Wang, Haichang


    Mitochondrial aldehyde dehydrogenase (ALDH2) is known to offer myocardial protection against stress conditions including ischemia-reperfusion injury, alcoholism and diabetes mellitus although the precise mechanism is unclear. This study was designed to evaluate the effect of ALDH2 on diabetes-induced myocardial injury with a focus on autophagy. Wild-type FVB and ALDH2 transgenic mice were challenged with streptozotozin (STZ, 200mg/kg, i.p.) for 3months to induce experimental diabetic cardiomyopathy. Diabetes triggered cardiac remodeling and contractile dysfunction as evidenced by cardiac hypertrophy, decreased cell shortening and prolonged relengthening duration, the effects of which were mitigated by ALDH2. Lectin staining displayed that diabetes promoted cardiac hypertrophy, the effect of which was alleviated by ALDH2. Western blot analysis revealed dampened autophagy protein markers including LC3B ratio and Atg7 along with upregulated p62 following experimental diabetes, the effect of which was reconciled by ALDH2. Phosphorylation level of AMPK was decreased and its downstream signaling molecule FOXO3a was upregulated in both diabetic cardiac tissue and in H9C2 cells with high glucose exposure. All these effect were partly abolished by ALDH2 overexpression and ALDH2 agonist Alda1. High glucose challenge dampened autophagy in H9C2 cells as evidenced by enhanced p62 levels and decreased levels of Atg7 and LC3B, the effect of which was alleviated by the ALDH2 activator Alda-1. High glucose-induced cell death and apoptosis were reversed by Alda-1. The autophagy inhibitor 3-MA and the AMPK inhibitor compound C mitigated Alda-1-offered beneficial effect whereas the autophagy inducer rapamycin mimicked or exacerbated high glucose-induced cell injury. Moreover, compound C nullified Alda-1-induced protection against STZ-induced changes in autophagy and function. Our results suggested that ALDH2 protects against diabetes-induced myocardial dysfunction possibly through an

  18. Use of cardiac biomarkers in neonatology. (United States)

    Vijlbrief, Daniel C; Benders, Manon J N L; Kemperman, Hans; van Bel, Frank; de Vries, Willem B


    Cardiac biomarkers are used to identify cardiac disease in term and preterm infants. This review discusses the roles of natriuretic peptides and cardiac troponins. Natriuretic peptide levels are elevated during atrial strain (atrial natriuretic peptide (ANP)) or ventricular strain (B-type natriuretic peptide (BNP)). These markers correspond well with cardiac function and can be used to identify cardiac disease. Cardiac troponins are used to assess cardiomyocyte compromise. Affected cardiomyocytes release troponin into the bloodstream, resulting in elevated levels of cardiac troponin. Cardiac biomarkers are being increasingly incorporated into clinical trials as indicators of myocardial strain. Furthermore, cardiac biomarkers can possibly be used to guide therapy and improve outcome. Natriuretic peptides and cardiac troponins are potential tools in the diagnosis and treatment of neonatal disease that is complicated by circulatory compromise. However, clear reference ranges need to be set and validation needs to be carried out in a population of interest.

  19. Effects of nicorandil on cardiac plasma membrane and cardiac mitochondrial membrane potential of guinea-pig%尼可地尔对豚鼠心肌细胞膜及线粒体膜电位的影响

    Institute of Scientific and Technical Information of China (English)

    冯力; 刘伊丽; 刘杰; 金春华


    研究KATP通道开放剂尼可地尔(Nic)对豚鼠心肌细胞膜和线粒体膜电位的影响.用激光共聚焦显微镜和特异性荧光探针,观察不同剂量的Nic及KATP通道阻滞剂格列本脲(Gli)引起急性分离的豚鼠心肌细胞膜电位,线粒体膜电位荧光值的变化.Nic1mmol.L-1引起细胞膜电位在1min内迅速超极化〔膜电位荧光值减少(75±12)%〕,Gli3μmol.L-1可阻断其变化;0.1和1mmol.L-1Nic可使线粒体膜电位去极化和膜电位荧光值在1,2,5min分别增加(12±3)%和(32±8)%,(25±6)%和(39±9)%,(34±6)%和(45±12)%;3μmol.L-1Gli可抑制其变化.结果说明低浓度Nic只引起线粒体膜电位去极化,高浓度Nic还可使细胞膜电位发生超极化,引起KATP通道开放.%With digital imaging techniques of advanced laser confocalmicroscope, effects of KATP channel opener nicorandil(Nic) on cardiac plasma membrane(CPM) and cardiac mitochondrial membrane(CMM) potential of guinea-pig were studied. It was found that Nic 1 mmol.L-1 caused the potential of CPM more negative (hyperpolarization), fluorescence intensity(FI) decreased by (75±12)% of baseline within 1 min, but no effect at 0.1 mmol.L-1. CMM was depolarized by 0.1 mmol.L-1 Nic〔FI increased by (12±3)%, (25±6)%, (34±6)% of baseline within 1, 2, 5 min〕, and by 1 mmol.L-1 Nic〔FI remarkably increased by (32±8)%, (39±9)%, (45±12)% of baseline〕. KATP channel blocker glibenclamide 3 μmol.L-1 itself caused no effect on potential of CPM and CMM, but blocked the above effect on potential of CPM and CMM induced by Nic. The results suggest that KATP channel of CMM is activated by low dose of Nic, and the high dose of Nic activate both KATP channels of CPM and CMM.

  20. [Mitochondrial diseases and stroke]. (United States)

    Irimia, P; Oliveros-Cid, A; Martínez-Vila, E


    We review the mitochondrial diseases in which cerebrovascular changes are seen, such as the MERRF syndrome (myoclonic epilepsy and ragged red fibers) or the Kearns-Sayre syndrome (progressive external ophthalmoplegia, retinitis pigmentaria, cerebellar disorders and disorders of cardiac conduction), focusing on the syndrome involving mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS). We consider the different clinical aspects, diagnostic methods, pathophysiological mechanisms of the cerebrovascular involvement as well as therapeutic approaches.

  1. Flow-based compromise detection

    NARCIS (Netherlands)

    Hofstede, Rick


    Brute-force attacks are omnipresent and manyfold on the Internet, and aim at compromising user accounts by issuing large numbers of authentication attempts on applications and daemons. Widespread targets of such attacks are Secure SHell (SSH) and Web applications, for example. The impact of brute-fo

  2. Mitochondrial dysfunction in heart failure. (United States)

    Rosca, Mariana G; Hoppel, Charles L


    Heart failure (HF) is a complex chronic clinical syndrome. Energy deficit is considered to be a key contributor to the development of both cardiac and skeletal myopathy. In HF, several components of cardiac and skeletal muscle bioenergetics are altered, such as oxygen availability, substrate oxidation, mitochondrial ATP production, and ATP transfer to the contractile apparatus via the creatine kinase shuttle. This review focuses on alterations in mitochondrial biogenesis and respirasome organization, substrate oxidation coupled with ATP synthesis in the context of their contribution to the chronic energy deficit, and mechanical dysfunction of the cardiac and skeletal muscle in HF. We conclude that HF is associated with decreased mitochondrial biogenesis and function in both heart and skeletal muscle, supporting the concept of a systemic mitochondrial cytopathy. The sites of mitochondrial defects are located within the electron transport and phosphorylation apparatus and differ with the etiology and progression of HF in the two mitochondrial populations (subsarcolemmal and interfibrillar) of cardiac and skeletal muscle. The roles of adrenergic stimulation, the renin-angiotensin system, and cytokines are evaluated as factors responsible for the systemic energy deficit. We propose a cyclic AMP-mediated mechanism by which increased adrenergic stimulation contributes to the mitochondrial dysfunction.

  3. Loss of mitochondrial exo/endonuclease EXOG affects mitochondrial respiration and induces ROS mediated cardiomyocyte hypertrophy

    NARCIS (Netherlands)

    Tigchelaar, Wardit; Yu, Hongjuan; De Jong, Anne Margreet; van Gilst, Wiek H; van der Harst, Pim; Westenbrink, B Daan; de Boer, Rudolf A; Sillje, Herman H W


    Recently, a genetic variant in the mitochondrial exo/endo nuclease EXOG, which has been implicated in mitochondrial DNA repair, was associated with cardiac function. The function of EXOG in cardiomyocytes is still elusive. Here we investigated the role of EXOG in mitochondrial function and hypertrop

  4. Loss of the nuclear receptor corepressor SLIRP compromises male fertility.

    Directory of Open Access Journals (Sweden)

    Shane M Colley

    Full Text Available Nuclear receptors (NRs and their coregulators play fundamental roles in initiating and directing gene expression influencing mammalian reproduction, development and metabolism. SRA stem Loop Interacting RNA-binding Protein (SLIRP is a Steroid receptor RNA Activator (SRA RNA-binding protein that is a potent repressor of NR activity. SLIRP is present in complexes associated with NR target genes in the nucleus; however, it is also abundant in mitochondria where it affects mitochondrial mRNA transcription and energy turnover. In further characterisation studies, we observed SLIRP protein in the testis where its localization pattern changes from mitochondrial in diploid cells to peri-acrosomal and the tail in mature sperm. To investigate the in vivo effects of SLIRP, we generated a SLIRP knockout (KO mouse. This animal is viable, but sub-fertile. Specifically, when homozygous KO males are crossed with wild type (WT females the resultant average litter size is reduced by approximately one third compared with those produced by WT males and females. Further, SLIRP KO mice produced significantly fewer progressively motile sperm than WT animals. Electron microscopy identified disruption of the mid-piece/annulus junction in homozygous KO sperm and altered mitochondrial morphology. In sum, our data implicates SLIRP in regulating male fertility, wherein its loss results in asthenozoospermia associated with compromised sperm structure and mitochondrial morphology.

  5. Cardiac mitochondria exhibit dynamic functional clustering

    Directory of Open Access Journals (Sweden)

    Felix Tobias Kurz


    Full Text Available Multi-oscillatory behavior of mitochondrial inner membrane potential ΔΨm in self-organized cardiac mitochondrial networks can be triggered by metabolic or oxidative stress. Spatio-temporal analyses of cardiac mitochondrial networks have shown that mitochondria are heterogeneously organized in synchronously oscillating clusters in which the mean cluster frequency and size are inversely correlated, thus suggesting a modulation of cluster frequency through local inter-mitochondrial coupling. In this study, we propose a method to examine the mitochondrial network's topology through quantification of its dynamic local clustering coefficients. Individual mitochondrial ΔΨm oscillation signals were identified for each cardiac myocyte and cross-correlated with all network mitochondria using previously described methods (Kurz et al., 2010. Time-varying inter-mitochondrial connectivity, defined for mitochondria in the whole network whose signals are at least 90% correlated at any given time point, allowed considering functional local clustering coefficients. It is shown that mitochondrial clustering in isolated cardiac myocytes changes dynamically and is significantly higher than for random mitochondrial networks that are constructed using the Erdös-Rényi model based on the same sets of vertices. The network's time-averaged clustering coefficient for cardiac myocytes was found to be 0.500 ± 0.051 (N=9 versus 0.061 ± 0.020 for random networks, respectively. Our results demonstrate that cardiac mitochondria constitute a network with dynamically connected constituents whose topological organization is prone to clustering. Cluster partitioning in networks of coupled oscillators has been observed in scale-free and chaotic systems and is therefore in good agreement with previous models of cardiac mitochondrial networks (Aon et al., 2008.

  6. Mitochondrial Dynamics in Mitochondrial Diseases

    Directory of Open Access Journals (Sweden)

    Juan M. Suárez-Rivero


    Full Text Available Mitochondria are very versatile organelles in continuous fusion and fission processes in response to various cellular signals. Mitochondrial dynamics, including mitochondrial fission/fusion, movements and turnover, are essential for the mitochondrial network quality control. Alterations in mitochondrial dynamics can cause neuropathies such as Charcot-Marie-Tooth disease in which mitochondrial fusion and transport are impaired, or dominant optic atrophy which is caused by a reduced mitochondrial fusion. On the other hand, mitochondrial dysfunction in primary mitochondrial diseases promotes reactive oxygen species production that impairs its own function and dynamics, causing a continuous vicious cycle that aggravates the pathological phenotype. Mitochondrial dynamics provides a new way to understand the pathophysiology of mitochondrial disorders and other diseases related to mitochondria dysfunction such as diabetes, heart failure, or Hungtinton’s disease. The knowledge about mitochondrial dynamics also offers new therapeutics targets in mitochondrial diseases.

  7. Unchanged mitochondrial organization and compartmentation of high-energy phosphates in creatine-deficient GAMT-/- mouse hearts. (United States)

    Branovets, Jelena; Sepp, Mervi; Kotlyarova, Svetlana; Jepihhina, Natalja; Sokolova, Niina; Aksentijevic, Dunja; Lygate, Craig A; Neubauer, Stefan; Vendelin, Marko; Birkedal, Rikke


    Disruption of the creatine kinase (CK) system in hearts of CK-deficient mice leads to changes in the ultrastructure and regulation of mitochondrial respiration. We expected to see similar changes in creatine-deficient mice, which lack the enzyme guanidinoacetate methyltransferase (GAMT) to produce creatine. The aim of this study was to characterize the changes in cardiomyocyte mitochondrial organization, regulation of respiration, and intracellular compartmentation associated with GAMT deficiency. Three-dimensional mitochondrial organization was assessed by confocal microscopy. On populations of permeabilized cardiomyocytes, we recorded ADP and ATP kinetics of respiration, competition between mitochondria and pyruvate kinase for ADP produced by ATPases, ADP kinetics of endogenous pyruvate kinase, and ATP kinetics of ATPases. These data were analyzed by mathematical models to estimate intracellular compartmentation. Quantitative analysis of morphological and kinetic data as well as derived model fits showed no difference between GAMT-deficient and wild-type mice. We conclude that inactivation of the CK system by GAMT deficiency does not alter mitochondrial organization and intracellular compartmentation in relaxed cardiomyocytes. Thus, our results suggest that the healthy heart is able to preserve cardiac function at a basal level in the absence of CK-facilitated energy transfer without compromising intracellular organization and the regulation of mitochondrial energy homeostasis. This raises questions on the importance of the CK system as a spatial energy buffer in unstressed cardiomyocytes.

  8. Hsp90 inhibition decreases mitochondrial protein turnover.

    Directory of Open Access Journals (Sweden)

    Daciana H Margineantu

    Full Text Available BACKGROUND: Cells treated with hsp90 inhibitors exhibit pleiotropic changes, including an expansion of the mitochondrial compartment, accompanied by mitochondrial fragmentation and condensed mitochondrial morphology, with ultimate compromise of mitochondrial integrity and apoptosis. FINDINGS: We identified several mitochondrial oxidative phosphorylation complex subunits, including several encoded by mtDNA, that are upregulated by hsp90 inhibitors, without corresponding changes in mRNA abundance. Post-transcriptional accumulation of mitochondrial proteins observed with hsp90 inhibitors is also seen in cells treated with proteasome inhibitors. Detailed studies of the OSCP subunit of mitochondrial F1F0-ATPase revealed the presence of mono- and polyubiquitinated OSCP in mitochondrial fractions. We demonstrate that processed OSCP undergoes retrotranslocation to a trypsin-sensitive form associated with the outer mitochondrial membrane. Inhibition of proteasome or hsp90 function results in accumulation of both correctly targeted and retrotranslocated mitochondrial OSCP. CONCLUSIONS: Cytosolic turnover of mitochondrial proteins demonstrates a novel connection between mitochondrial and cytosolic compartments through the ubiquitin-proteasome system. Analogous to defective protein folding in the endoplasmic reticulum, a mitochondrial unfolded protein response may play a role in the apoptotic effects of hsp90 and proteasome inhibitors.

  9. Mitochondria-Targeted Antioxidant Prevents Cardiac Dysfunction Induced by Tafazzin Gene Knockdown in Cardiac Myocytes

    Directory of Open Access Journals (Sweden)

    Quan He


    Full Text Available Tafazzin, a mitochondrial acyltransferase, plays an important role in cardiolipin side chain remodeling. Previous studies have shown that dysfunction of tafazzin reduces cardiolipin content, impairs mitochondrial function, and causes dilated cardiomyopathy in Barth syndrome. Reactive oxygen species (ROS have been implicated in the development of cardiomyopathy and are also the obligated byproducts of mitochondria. We hypothesized that tafazzin knockdown increases ROS production from mitochondria, and a mitochondria-targeted antioxidant prevents tafazzin knockdown induced mitochondrial and cardiac dysfunction. We employed cardiac myocytes transduced with an adenovirus containing tafazzin shRNA as a model to investigate the effects of the mitochondrial antioxidant, mito-Tempo. Knocking down tafazzin decreased steady state levels of cardiolipin and increased mitochondrial ROS. Treatment of cardiac myocytes with mito-Tempo normalized tafazzin knockdown enhanced mitochondrial ROS production and cellular ATP decline. Mito-Tempo also significantly abrogated tafazzin knockdown induced cardiac hypertrophy, contractile dysfunction, and cell death. We conclude that mitochondria-targeted antioxidant prevents cardiac dysfunction induced by tafazzin gene knockdown in cardiac myocytes and suggest mito-Tempo as a potential therapeutic for Barth syndrome and other dilated cardiomyopathies resulting from mitochondrial oxidative stress.

  10. 26 CFR 301.7122-1 - Compromises. (United States)


    ... for taxes, interest, or penalties. Unless the terms of the offer and acceptance expressly provide otherwise, acceptance of an offer to compromise a civil liability does not remit a criminal liability, nor does acceptance of an offer to compromise a criminal liability remit a civil liability. (b) Grounds...

  11. Mitochondrial Diseases (United States)

    ... disorder, something goes wrong with this process. Mitochondrial diseases are a group of metabolic disorders. Mitochondria are ... cells and cause damage. The symptoms of mitochondrial disease can vary. It depends on how many mitochondria ...

  12. Mitochondrial haplogroups

    DEFF Research Database (Denmark)

    Benn, Marianne; Schwartz, Marianne; Nordestgaard, Børge G;


    Rare mutations in the mitochondrial genome may cause disease. Mitochondrial haplogroups defined by common polymorphisms have been associated with risk of disease and longevity. We tested the hypothesis that common haplogroups predict risk of ischemic cardiovascular disease, morbidity from other...

  13. Molecular Aspects of Exercise-induced Cardiac Remodeling. (United States)

    Bernardo, Bianca C; McMullen, Julie R


    Exercise-induced cardiac remodeling is typically an adaptive response associated with cardiac myocyte hypertrophy and renewal, increased cardiac myocyte contractility, sarcomeric remodeling, cell survival, metabolic and mitochondrial adaptations, electrical remodeling, and angiogenesis. Initiating stimuli/triggers of cardiac remodeling include increased hemodynamic load, increased sympathetic activity, and the release of hormones and growth factors. Prolonged and strenuous exercise may lead to maladaptive exercise-induced cardiac remodeling including cardiac dysfunction and arrhythmia. In addition, this article describes novel therapeutic approaches for the treatment of heart failure that target mechanisms responsible for adaptive exercise-induced cardiac remodeling, which are being developed and tested in preclinical models.

  14. Mitochondrial genetics


    Chinnery, Patrick Francis; Hudson, Gavin


    Introduction In the last 10 years the field of mitochondrial genetics has widened, shifting the focus from rare sporadic, metabolic disease to the effects of mitochondrial DNA (mtDNA) variation in a growing spectrum of human disease. The aim of this review is to guide the reader through some key concepts regarding mitochondria before introducing both classic and emerging mitochondrial disorders. Sources of data In this article, a review of the current mitochondrial genetics literature was con...

  15. Up-Regulation of Mitochondrial Antioxidant Superoxide Dismutase Underpins Persistent Cardiac Nutritional-Preconditioning by Long Chain n-3 Polyunsaturated Fatty Acids in the Rat

    Directory of Open Access Journals (Sweden)

    Grace G. Abdukeyum


    Full Text Available Reactive oxygen species paradoxically underpin both ischaemia/reperfusion (I/R damage and ischaemic preconditioning (IPC cardioprotection. Long-chain omega-3 polyunsaturated fatty acids (LCn-3 PUFA are highly susceptible to peroxidation, but are paradoxically cardioprotective. This study tested the hypothesis that LCn-3 PUFA cardioprotection is underpinned by peroxidation, upregulating antioxidant activity to reduce I/R-induced lipid oxidation, and the mechanisms of this nutritional preconditioning contrast to mechanisms of IPC. Rats were fed: fish oil (LCn-3 PUFA; sunflower seed oil (n-6 PUFA; or beef tallow (saturated fat, SF enriched diets for six weeks. Isolated hearts were subject to: 180 min normoxic perfusion; a 30 min coronary occlusion ischaemia protocol then 120 min normoxic reperfusion; or a 3 × 5 min global IPC protocol, 30 min ischaemia, then reperfusion. Dietary LCn-3 PUFA raised basal: membrane docosahexaenoic acid (22:6n-3 DHA; fatty acid peroxidisability index; concentrations of lipid oxidation products; and superoxide dismutase (MnSOD activity (but not CuZnSOD or glutathione peroxidase. Infarct size correlated inversely with basal MnSOD activity (r2 = 0.85 in the ischaemia protocol and positively with I/R-induced lipid oxidation (lipid hydroperoxides (LPO, r2 = 0.475; malondialdehyde (MDA, r2 = 0.583 across ischaemia and IPC protocols. While both dietary fish oil and IPC infarct-reduction were associated with reduced I/R-induced lipid oxidation, fish oil produced nutritional preconditioning by prior LCn-3 PUFA incorporation and increased peroxidisability leading to up-regulated mitochondrial SOD antioxidant activity.

  16. SIRT3 in cardiac physiology and disease

    Directory of Open Access Journals (Sweden)

    Christoph Koentges


    Full Text Available Functional defects in mitochondrial biology causally contribute to various human diseases, including cardiovascular disease. Impairment in oxidative phosphorylation, mitochondrial oxidative stress and increased opening of the mitochondrial permeability transition pore add to the underlying mechanisms of heart failure or myocardial ischemia reperfusion (IR injury. Recent evidence demonstrated that the mitochondrial NAD+-dependent deacetylase sirtuin 3 (SIRT3 may regulate these mitochondrial functions by reversible protein lysine deacetylation. Loss of function studies demonstrated a role of impaired SIRT3 activity in the pathogenesis of myocardial IR injury as well as in the development of cardiac hypertrophy and the transition into heart failure. Gain of function studies and treatment approaches increasing mitochondrial NAD+ availability that ameliorate these cardiac pathologies have led to the proposal that activation of SIRT3 may represent a promising therapeutic strategy to improve mitochondrial derangements in various cardiac pathologies. In the current review, we will present and discuss the available literature on the role of SIRT3 in cardiac physiology and disease.

  17. Cardiac manifestations of patients with mitochondrial disease%回顾性调查线粒体疾病患者的心脏病变

    Institute of Scientific and Technical Information of China (English)

    张丽华; 方理刚; 程中伟; 方全


    Objective To analyze the cardiac manifestations of mitochondriopathy patients. Methods We retrospectively analyzed the clinical (Electrocardiogram, Hoher monitoring, echocardiogram and laboratory examinations) and pathological data of 90 mitochondriopathy patients diagnosed within recent 20 years. The cardiac involvement data from these patients were summarized. Results Hypertrophic eardiomyopathy was found in 2 patients and dilated cardiomyopathy in 3 patients Mitochondriopathy diagnosis was made in 1 patient two years after heart transplantation due to heart failure resulting from previously diagnosed hypertrophic cardiomyopathy with noncompaction. The prevalence of cardiomyopathy is 5. 6% (5/90). The prevalence of various arrhythmias was 22. 2% (20/90). Four patients received permanent pacemaker because of Adams-Stokes attack or bradyarrhythmias ( mitochondriopathy diagnosis was made 1-3 years post pacemaker implantation in 3 cases). History of syncope, respiratory failure, RBBB, atrial fibrillation and episodic ventricular tachyarrhythmias were presented in 1 patient with mitochondriopathy, another mitochondriopathy patient developed atrial tachyarrhythmias. Arrhythmia were present in 14 mitochondriopathy patients including RBBB, bifascicularblock, intraventricularblock, Wolff-Parkinson-White syndrome and short PR interval syndrome. The mtDNA 3243A-G mutation was detected in 8 patients. Conclusions Incidence of cardiomyopathy, heart failure and severe arrhythmias is high in patients with mitochondriopathy. Therefore, young cardiomyopathy patients with severe conduction block disorders should undergo relevant etiologic and genetic screening for mitochondriopathy and patients with diagnosed mitochondriopathy should regularly receive electrocardiogram and echocardiography examinations for possible cardiac involvement.%目的 分析线粒体疾病心脏受累的表现,提高对该病的认识.方法 回顾北京协和医院20年来诊断的90例线粒体疾病患

  18. Obesity May Not Compromise Knee Surgery Success (United States)

    ... 164282.html Obesity May Not Compromise Knee Surgery Success Results similar after procedure to repair meniscus in ... the surgery and they would have the same success as someone who is not as heavy," he ...

  19. Mitochondrial vasculopathy

    Institute of Scientific and Technical Information of China (English)

    Josef Finsterer; Sinda Zarrouk-Mahjoub


    Mitochondrial disorders(MIDs)are usually multisystem disorders(mitochondrial multiorgan disorder syndrome)either on from onset or starting at a point during the disease course.Most frequently affected tissues are those with a high oxygen demand such as the central nervous system,the muscle,endocrine glands,or the myocardium.Recently,it has been shown that rarely alsothe arteries may be affected(mitochondrial arteriopathy).This review focuses on the type,diagnosis,and treat-ment of mitochondrial vasculopathy in MID patients.A literature search using appropriate search terms was carried out.Mitochondrial vasculopathy manifests as either microangiopathy or macroangiopathy.Clinical manifestations of mitochondrial microangiopathy include leukoencephalopathy,migraine-like headache,stroke-like episodes,or peripheral retinopathy.Mitochondrial macroangiopathy manifests as atherosclerosis,ectasia of arteries,aneurysm formation,dissection,or spontan-eous rupture of arteries.The diagnosis relies on the documentation and confirmation of the mitochondrial metabolic defect or the genetic cause after exclusion of non-MID causes.Treatment is not at variance compared to treatment of vasculopathy due to non-MID causes.Mitochondrial vasculopathy exists and manifests as micro-or macroangiopathy.Diagnosing mitochondrial vasculopathy is crucial since appropriate treatment may prevent from severe complications.

  20. Phosphodiesterase-3 inhibitor (cilostazol) attenuates oxidative stress-induced mitochondrial dysfunction in the heart

    Institute of Scientific and Technical Information of China (English)

    Siriporn C.Chattipakorn; Savitree Thummasorn; Jantira Sanit; Nipon Chattipakorn


    Background Cilostazol is a type 3 phosphodiesterase inhibitor which has been previously demonstrated to prevent the occurrence of tachyarrhythmia and improve defibrillation efficacy. However, the mechanism for this beneficial effect is still unclear. Since cardiac mito-chondria have been shown to play a crucial role in fatal cardiac arrhythmias and that oxidative stress is one of the main contributors to arr-hythmia generation, we tested the effects of cilostazol on cardiac mitochondria under severe oxidative stress. Methods Mitochondria were isolated from rat hearts and treated with H2O2 to induce oxidative stress. Cilostazol, at various concentrations, was used to study its protective effects. Pharmacological interventions, including a mitochondrial permeability transition pore (mPTP) blocker, cyclosporine A (CsA), and an inner membrane anion channel (IMAC) blocker, 4’-chlorodiazepam (CDP), were used to investigate the mechanistic role of cilostazol on cardiac mitochondria. Cardiac mitochondrial reactive oxygen species (ROS) production, mitochondrial membrane potential change and mi-tochondrial swelling were determined as indicators of cardiac mitochondrial function. Results Cilostazol preserved cardiac mitochondrial function when exposed to oxidative stress by preventing mitochondrial depolarization, mitochondrial swelling, and decreasing ROS produc-tion. Conclusions Our findings suggest that cardioprotective effects of cilostazol reported previously could be due to its prevention of car-diac mitochondrial dysfunction caused by severe oxidative stress.

  1. Mitochondrial Mechanisms in Septic Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    María Cecilia Cimolai


    Full Text Available Sepsis is the manifestation of the immune and inflammatory response to infection that may ultimately result in multi organ failure. Despite the therapeutic strategies that have been used up to now, sepsis and septic shock remain a leading cause of death in critically ill patients. Myocardial dysfunction is a well-described complication of severe sepsis, also referred to as septic cardiomyopathy, which may progress to right and left ventricular pump failure. Many substances and mechanisms seem to be involved in myocardial dysfunction in sepsis, including toxins, cytokines, nitric oxide, complement activation, apoptosis and energy metabolic derangements. Nevertheless, the precise underlying molecular mechanisms as well as their significance in the pathogenesis of septic cardiomyopathy remain incompletely understood. A well-investigated abnormality in septic cardiomyopathy is mitochondrial dysfunction, which likely contributes to cardiac dysfunction by causing myocardial energy depletion. A number of mechanisms have been proposed to cause mitochondrial dysfunction in septic cardiomyopathy, although it remains controversially discussed whether some mechanisms impair mitochondrial function or serve to restore mitochondrial function. The purpose of this review is to discuss mitochondrial mechanisms that may causally contribute to mitochondrial dysfunction and/or may represent adaptive responses to mitochondrial dysfunction in septic cardiomyopathy.

  2. Cardiac arrest (United States)

    ... Article.jsp. Accessed June 16, 2014. Myerburg RJ, Castellanos A. Approach to cardiac arrest and life-threatening ... PA: Elsevier Saunders; 2011:chap 63. Myerburg RJ, Castellanos A. Cardiac arrest and audden aardiac death. In: ...

  3. Choreographies with Secure Boxes and Compromised Principals

    CERN Document Server

    Carbone, Marco; 10.4204/EPTCS.12.1


    We equip choreography-level session descriptions with a simple abstraction of a security infrastructure. Message components may be enclosed within (possibly nested) "boxes" annotated with the intended source and destination of those components. The boxes are to be implemented with cryptography. Strand spaces provide a semantics for these choreographies, in which some roles may be played by compromised principals. A skeleton is a partially ordered structure containing local behaviors (strands) executed by regular (non-compromised) principals. A skeleton is realized if it contains enough regular strands so that it could actually occur, in combination with any possible activity of compromised principals. It is delivery guaranteed (DG) realized if, in addition, every message transmitted to a regular participant is also delivered. We define a novel transition system on skeletons, in which the steps add regular strands. These steps solve tests, i.e. parts of the skeleton that could not occur without additional regu...

  4. Choreographies with Secure Boxes and Compromised Principals

    DEFF Research Database (Denmark)

    Carbone, Marco; Guttman, Joshua


      We equip choreography-level session descriptions with a simple abstraction of a security infrastruc- ture. Message components may be enclosed within (possibly nested) ”boxes” annotated with the intended source and destination of those components. The boxes are to be implemented with cryp......- tography. Strand spaces provide a semantics for these choreographies, in which some roles may be played by compromised principals. A skeleton is a partially ordered structure containing local behaviors (strands) executed by regular (non-compromised) principals. A skeleton is realized if it contains enough...... it embeds. Second, if no step is possible from a skeleton A, then A is DG realized. Finally, if a DG realized A′ is accessible from A, then A′ is minimal. Thus, the transition system provides a systematic way to construct the possible behaviors of the choreography, in the presence of compromised principals.  ...

  5. Left Ventricular Gene Expression Profile of Healthy and Cardiovascular Compromised Rat Models Used in Air Pollution Studies (United States)

    The link between pollutant exposure and cardiovascular disease (CVD) has prompted mechanistic research with animal models of CVD. We hypothesized that the cardiac gene expression patterns of healthy and genetically compromised, CVD-prone rat models, with or without metabolic impa...

  6. Uneasy Compromise: Language and Education in Moldova (United States)

    Ciscel, Matthew


    This study reports on the uneasy compromise in language and education policies in the post-Soviet Republic of Moldova since its first moves toward independence in 1989. Taking an approach that posits language policies as needing to be anchored in both international norms and the idiosyncrasies of local conditions, the discussion explores the…

  7. Mitochondrial disorders. (United States)

    Zeviani, M; Tiranti, V; Piantadosi, C


    Mitochondrial respiration, the most efficient metabolic pathway devoted to energy production, is at the crosspoint of 2 quite different genetic systems, the nuclear genome and the mitochondrial genome (mitochondrial DNA, mtDNA). The latter encodes a few essential components of the mitochondrial respiratory chain and has unique molecular and genetic properties that account for some of the peculiar features of mitochondrial disorders. However, the perpetuation, propagation, and expression of mtDNA, the majority of the subunits of the respiratory complexes, as well as a number of genes involved in their assembly and turnover, are contained in the nuclear genome. Although mitochondrial disorders have been known for more than 30 years, a major breakthrough in their understanding has come much later, with the discovery of an impressive, ever-increasing number of mutations of mitochondrial DNA. Partial deletions or duplications of mtDNA, or maternally inherited point mutations, have been associated with well-defined clinical syndromes. However, phenotypes transmitted as mendelian traits have also been identified. These include clinical entities defined on the basis of specific biochemical defects, and also a few autosomal dominant or recessive syndromes associated with multiple deletions or tissue-specific depletion of mtDNA. Given the complexity of mitochondrial genetics and biochemistry, the clinical manifestations of mitochondrial disorders are extremely heterogenous. They range from lesions of single tissues or structures, such as the optic nerve in Leber hereditary optic neuropathy or the cochlea in maternally inherited nonsyndromic deafness, to more widespread lesions including myopathies, encephalomyopathies, cardiopathies, or complex multisystem syndromes. The recent advances in genetic studies provide both diagnostic tools and new pathogenetic insights in this rapidly expanding area of human pathology.


    Directory of Open Access Journals (Sweden)

    Enrique eBalderas


    Full Text Available Since its discovery in a glioma cell line 15 years ago, mitochondrial BKCa channel (mitoBKCa has been studied in brain cells and cardiomyocytes sharing general biophysical properties such as high K+ conductance (~300 pS, voltage-dependency and Ca2+-sensitivity. Main advances in deciphering the molecular composition of mitoBKCa have included establishing that it is encoded by the Kcnma1 gene, that a C-terminal splice insert confers mitoBKCa ability to be targeted to cardiac mitochondria, and evidence for its potential coassembly with β subunits. Notoriously, β1 subunit directly interacts with cytochrome c oxidase and mitoBKCa can be modulated by substrates of the respiratory chain. mitoBKCa channel has a central role in protecting the heart from ischemia, where pharmacological activation of the channel impacts the generation of reactive oxygen species and mitochondrial Ca2+ preventing cell death likely by impeding uncontrolled opening of the mitochondrial transition pore. Supporting this view, inhibition of mitoBKCa with Iberiotoxin, enhances cytochrome c release from glioma mitochondria. Many tantalizing questions remain. Some of them are: how is mitoBKCa coupled to the respiratory chain? Does mitoBKCa play non-conduction roles in mitochondria physiology? Which are the functional partners of mitoBKCa? What are the roles of mitoBKCa in other cell types? Answers to these questions are essential to define the impact of mitoBKCa channel in mitochondria biology and disease.

  9. 19 CFR 172.33 - Acceptance of offers in compromise. (United States)


    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Acceptance of offers in compromise. 172.33 Section... OF THE TREASURY (CONTINUED) CLAIMS FOR LIQUIDATED DAMAGES; PENALTIES SECURED BY BONDS Offers in Compromise § 172.33 Acceptance of offers in compromise. An offer in compromise will be considered...

  10. 19 CFR 171.32 - Acceptance of offers in compromise. (United States)


    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Acceptance of offers in compromise. 171.32 Section... OF THE TREASURY (CONTINUED) FINES, PENALTIES, AND FORFEITURES Offers in Compromise § 171.32 Acceptance of offers in compromise. An offer in compromise will be considered accepted only when the...

  11. Cardiac Sarcoidosis. (United States)

    Birnie, David; Ha, Andrew C T; Gula, Lorne J; Chakrabarti, Santabhanu; Beanlands, Rob S B; Nery, Pablo


    Studies suggest clinically manifest cardiac involvement occurs in 5% of patients with pulmonary/systemic sarcoidosis. The principal manifestations of cardiac sarcoidosis (CS) are conduction abnormalities, ventricular arrhythmias, and heart failure. Data indicate that an 20% to 25% of patients with pulmonary/systemic sarcoidosis have asymptomatic (clinically silent) cardiac involvement. An international guideline for the diagnosis and management of CS recommends that patients be screened for cardiac involvement. Most studies suggest a benign prognosis for patients with clinically silent CS. Immunosuppression therapy is advocated for clinically manifest CS. Device therapy, with implantable cardioverter defibrillators, is recommended for some patients.

  12. Objections to the Libertarian Stem Cell Compromise

    Directory of Open Access Journals (Sweden)

    Walter E. Block


    Full Text Available In Block (2010 I offered a compromise between the pro choice position that fervently supports stem cell research, and the pro life philosophy which bitterly opposes it. The compromise was a contest: allow would be researchers to create as many fertilized eggs as they wished. But, also, these should be offered up to would be parents to adopt all of these “children” as they wanted. If and only if there were any unadopted fetuses remaining in the laboratories of the nation would it be licit, on libertarian grounds, for research on them to take place. In the present paper I respond to several objections to this “modest proposal.”

  13. Strained Compromises? Danish Flexicurity During Crisis

    DEFF Research Database (Denmark)

    Ibsen, Christian Lyhne


    The Danish concept of flexicurity in a ‘Golden Triangle’ of low job protection, high income security and high employment security is not only about a balance between labor market flexibility and social security. Arguably, it is also a series of more or less stable underlying compromises between...... social partners about the main mechanisms and aims of labor market regulation which – supposedly – should be focused on employment rather than jobs, and competition on quality rather than on labor costs. However, the ‘Golden Triangle’ – this article argues – seems in need of complementary concepts...... Denmark in 2008, this article investigates if and how the recession challenged these compromises by comparing two rounds of casebased interviews in three metalworking companies in 2007 and 2009. It is shown that practice has indeed changed – albeit modestly – due to worsened economic circumstances...

  14. Radiosurgical planning of meningiomas: compromises with conformity. (United States)

    Rowe, Jeremy G; Walton, Lee; Vaughan, Paul; Malik, Irfan; Radatz, Matthias; Kemeny, Andras


    The radiosurgical planning of meningiomas frequently necessitates compromises between irradiating tumour and risking damage to adjacent structures. In selected cases, we resolved this by excluding part of the tumour from the prescription isodose volume. Most of these compromises or 'suboptimal' plans achieved growth control. Growth control could not be related to conformity indices or to various measures of the radiation dose received by the meningioma. Examining recurrences, 75% arose from dura outside the original treatment field. These findings are discussed in terms of dose prescription protocols and the use of conformity indices in planning. The importance of the dural origin of meningiomas is well established in surgical practice, as reflected by Simpson's grades, but may be equally significant in radiosurgical practice.

  15. When data representation compromise data security

    DEFF Research Database (Denmark)

    Simonsen, Eivind Ortind; Dahl, Mads Ronald

    on the internet over many years? A new legislation proposed in 2012 by the European Commission on protection of personal data will be implemented from 2015. The new law will impose sanction options ranging from a warning to a fine up to 100.000.000 EUR. We argue that this new law will lead to especially......WHEN DATA REPRESENTATION COMPROMISE DATA SECURITY The workflow of transforming data into informative representations makes extensive usage of computers and software. Scientists have a conventional tradition for producing publications that include tables and graphs as data representations....... These representations can be used for multiple purposes such as publications in journals, teaching and conference material. But when created, stored and distributed in a digital form there is a risk of compromising data security. Data beyond the once used specifically to create the representation can be included...

  16. Elevated mitochondrial oxidative stress impairs metabolic adaptations to exercise in skeletal muscle.

    Directory of Open Access Journals (Sweden)

    Justin D Crane

    Full Text Available Mitochondrial oxidative stress is a complex phenomenon that is inherently tied to energy provision and is implicated in many metabolic disorders. Exercise training increases mitochondrial oxidative capacity in skeletal muscle yet it remains unclear if oxidative stress plays a role in regulating these adaptations. We demonstrate that the chronic elevation in mitochondrial oxidative stress present in Sod2 (+/- mice impairs the functional and biochemical mitochondrial adaptations to exercise. Following exercise training Sod2 (+/- mice fail to increase maximal work capacity, mitochondrial enzyme activity and mtDNA copy number, despite a normal augmentation of mitochondrial proteins. Additionally, exercised Sod2 (+/- mice cannot compensate for their higher amount of basal mitochondrial oxidative damage and exhibit poor electron transport chain complex assembly that accounts for their compromised adaptation. Overall, these results demonstrate that chronic skeletal muscle mitochondrial oxidative stress does not impact exercise induced mitochondrial biogenesis, but impairs the resulting mitochondrial protein function and can limit metabolic plasticity.

  17. Cardiac Malpositions

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Shi Joon; Im, Chung Gie; Yeon, Kyung Mo; Hasn, Man Chung [Seoul National University College of Medicine, Seoul (Korea, Republic of)


    Cardiac Malposition refers to any position of the heart other than a left-sided heart in a situs solitus individual. Associated cardiac malformations are so complex that even angiocardiographic and autopsy studies may not afford an accurate information. Although the terms and classifications used to describe the internal cardiac anatomy and their arterial connections in cardiac malpositions differ and tend to be confusing, common agreement exists on the need for a segmental approach to diagnosis. Authors present 18 cases of cardiac malpositions in which cardiac catheterization and angiocardiography were done at the Department of Radiology, Seoul National University Hospital between 1971 and 1979. Authors analyzed the clinical, radiographic, operative and autopsy findings with the emphasis on the angiocardiographic findings. The results are as follows: 1. Among 18 cases with cardiac malpositions, 6 cases had dextrocardia with situs inversus, 9 cases had dextrocardia with situs solitus and 3 cases had levocardia with situs inversus. 2. There was no genuine exception to visceroatrial concordance rule. 3. Associated cardiac malpositions were variable and complex with a tendency of high association of transposition and double outlet varieties with dextrocardia in situs solitus and levocardia in situs inversus. Only one in 6 cases of dextrocardia with situs inversus had pure transposition. 4. In two cases associated pulmonary atresia was found at surgery which was not predicted by angiocardiography. 5. Because many of the associated complex lesions can be corrected surgically provided the diagnosis is accurate, the selective biplane angiocardiography with or without cineradiography is essential.

  18. Democracy as a Way to Social Compromise

    Institute of Scientific and Technical Information of China (English)

    Han Zhen


    In modem society,democracy as a symbol of social civilization and progress is cherished.Any government or organization,whether truly democratic or not,will claim that it is democratic while its opponents are not.However,as a historical notion,democracy does not possess the quality of absoluteness.In my view,democracy,in its original meaning,should be understood as a way to social compromise,whose aim is to guarantee a relatively fair political life.

  19. Mitochondrial fatty acid oxidation alterations in heart failure, ischaemic heart disease and diabetic cardiomyopathy. (United States)

    Fillmore, N; Mori, J; Lopaschuk, G D


    Heart disease is a leading cause of death worldwide. In many forms of heart disease, including heart failure, ischaemic heart disease and diabetic cardiomyopathies, changes in cardiac mitochondrial energy metabolism contribute to contractile dysfunction and to a decrease in cardiac efficiency. Specific metabolic changes include a relative increase in cardiac fatty acid oxidation rates and an uncoupling of glycolysis from glucose oxidation. In heart failure, overall mitochondrial oxidative metabolism can be impaired while, in ischaemic heart disease, energy production is impaired due to a limitation of oxygen supply. In both of these conditions, residual mitochondrial fatty acid oxidation dominates over mitochondrial glucose oxidation. In diabetes, the ratio of cardiac fatty acid oxidation to glucose oxidation also increases, although primarily due to an increase in fatty acid oxidation and an inhibition of glucose oxidation. Recent evidence suggests that therapeutically regulating cardiac energy metabolism by reducing fatty acid oxidation and/or increasing glucose oxidation can improve cardiac function of the ischaemic heart, the failing heart and in diabetic cardiomyopathies. In this article, we review the cardiac mitochondrial energy metabolic changes that occur in these forms of heart disease, what role alterations in mitochondrial fatty acid oxidation have in contributing to cardiac dysfunction and the potential for targeting fatty acid oxidation to treat these forms of heart disease.

  20. Cardiac cameras. (United States)

    Travin, Mark I


    Cardiac imaging with radiotracers plays an important role in patient evaluation, and the development of suitable imaging instruments has been crucial. While initially performed with the rectilinear scanner that slowly transmitted, in a row-by-row fashion, cardiac count distributions onto various printing media, the Anger scintillation camera allowed electronic determination of tracer energies and of the distribution of radioactive counts in 2D space. Increased sophistication of cardiac cameras and development of powerful computers to analyze, display, and quantify data has been essential to making radionuclide cardiac imaging a key component of the cardiac work-up. Newer processing algorithms and solid state cameras, fundamentally different from the Anger camera, show promise to provide higher counting efficiency and resolution, leading to better image quality, more patient comfort and potentially lower radiation exposure. While the focus has been on myocardial perfusion imaging with single-photon emission computed tomography, increased use of positron emission tomography is broadening the field to include molecular imaging of the myocardium and of the coronary vasculature. Further advances may require integrating cardiac nuclear cameras with other imaging devices, ie, hybrid imaging cameras. The goal is to image the heart and its physiological processes as accurately as possible, to prevent and cure disease processes.

  1. Mitochondrial Myopathy (United States)

    ... diseases are caused by CoQ10 deficiency, and CoQ10 supplementation is clearly beneficial in these cases. It might provide some relief from other mitochondrial diseases. Creatine, L-carnitine, and CoQ10 supplements often are combined into a “ ...

  2. Cardiac echinococcosis

    Directory of Open Access Journals (Sweden)

    Ivanović-Krstić Branislava A.


    Full Text Available Cardiac hydatid disease is rare. We report on an uncommon hydatid cyst localized in the right ventricular wall, right atrial wall tricuspid valve left atrium and pericard. A 33-year-old woman was treated for cough, fever and chest pain. Cardiac echocardiograpic examination revealed a round tumor (5.8 x 4 cm in the right ventricular free wall and two smaller cysts behind that tumor. There were cysts in right atrial wall and tricuspidal valve as well. Serologic tests for hydatidosis were positive. Computed tomography finding was consistent with diagnosis of hydatid cyst in lungs and right hylar part. Surgical treatment was rejected due to great risk of cardiac perforation. Medical treatment with albendazole was unsuccessful and the patient died due to systemic hydatid involvement of the lungs, liver and central nervous system.

  3. Mitochondrial accumulation under oxidative stress is due to defects in autophagy. (United States)

    Luo, Cheng; Li, Yan; Wang, Hui; Feng, Zhihui; Li, Yuan; Long, Jiangang; Liu, Jiankang


    Mitochondrial dynamics maintains normal mitochondrial function by degrading damaged mitochondria and generating newborn mitochondria. The accumulation of damaged mitochondria influences the intracellular environment by promoting mitochondrial dysfunction, and thus initiating a vicious cycle. Oxidative stress induces mitochondrial malfunction, which is involved in many cardiovascular diseases. However, the mechanism of mitochondrial accumulation in cardiac myoblasts remains unclear. We observed mitochondrial dysfunction and an increase in mitochondrial mass under the oxidative conditions produced by tert-butyl hydroperoxide (tBHP) in cardiac myoblast H9c2 cells. However, in contrast to the increase in mitochondrial mass, mitochondrial DNA (mtDNA) decreased, suggesting that enhanced mitochondrial biogenesis may be not the primary cause of the mitochondrial accumulation. Therefore, we investigated changes in a number of proteins involved in autophagy. Beclin1, Atg12-Atg5 conjugate, Atg7 contents decreased but LC3-II accumulated in tBHP-treated H9c2 cells. Moreover, the capacity for acid hydrolysis decreased in H9c2 cells. We also demonstrated a decrease in DJ-1 protein under the oxidative conditions that deregulate mitochondrial dynamics. These results reveal that autophagy became defective under oxidative stress. We therefore suggest that defects in autophagy mediate mitochondrial accumulation under these conditions.

  4. Orthodontic management of a periodontally compromised dentition

    Directory of Open Access Journals (Sweden)

    Prashant K Zaveri


    Full Text Available Malocclusion superimposed with severe periodontitis may present a great challenge to clinicians while providing orthodontic treatment due the episodic and site-specific nature of the disease with risk of rapid tissue breakdown. However, orthodontic treatment in such situation may contribute significantly to the overall rehabilitation both functionally and esthetically. In this article, a case report outlines a combined periodontic-orthodontic management of compromised dentition. A 37-year-old female patient with significant medical history was treated for Class II Division 1 type of malocclusion associated with spaced upper and lower anterior teeth, deep overbite, and increased overjet, superimposed with chronic generalized periodontitis and bone loss. Treatment was completed using temporary anchorage devices assisted strategically applied force and modified tandem retraction biomechanics amidst management of acute inflammatory episodes during and mucogingival complication after treatment. Affected areas healed very well after post-orthodontic periodontal treatment with minimal pocket depth, and bleeding on probing, and a healthy zone of attached gingiva at the follow up visits. The orthodontic results lead to improvement in patient's facial profile, lip posture, and correction of protrusion which addressed her main concern. One year follow-up shows good orthodontic and periodontic stability. The report highlights the importance of identifying “at risk” individuals and continuous monitoring of disease status during treatment. Despite all precautionary measures, a flare-up during the treatment can be anticipated.

  5. Dynamics of discrete opinions without compromise

    CERN Document Server

    Öztürk, M Kaan


    A new agent-based, bounded-confidence model for discrete one-dimensional opinion dynamics is presented. The agents interact if their opinions do not differ more than a tolerance parameter. In pairwise interactions, one of the pair, randomly selected, converts to the opinion of the other. The model can be used to simulate cases where no compromise is possible, such as exclusive choices or competing brands. The fully-mixed case with maximum tolerance is equivalent to the Gambler's Ruin problem. A fully-mixed system always ends up in an absorbing state, which can have one or more surviving opinions. An upper bound for the final number of opinions is given. The distribution of absorption times fits the generalized extreme value distribution. The diffusion coefficient of an opinion increases linearly with the number of opinions within the tolerance parameter. A general master equation and specific Markov matrices are given. The software code developed for this study is provided as a supplement.

  6. Conflicting perspectives compromising discussions on cardiopulmonary resuscitation.

    LENUS (Irish Health Repository)

    Groarke, J


    Healthcare professionals, patients and their relatives are expected to discuss resuscitation together. This study aims to identify the differences in the knowledge base and understanding of these parties. Questionnaires examining knowledge and opinion on resuscitation matters were completed during interviews of randomly selected doctors, nurses and the general public. 70% doctors, 24% nurses and 0% of a public group correctly estimated survival to discharge following in-hospital resuscitation attempts. Deficiencies were identified in doctor and nurse knowledge of ethics governing resuscitation decisions. Public opinion often conflicts with ethical guidelines. Public understanding of the nature of cardiopulmonary arrests and resuscitation attempts; and of the implications of a \\'Do Not Attempt Resuscitation (DNAR)\\' order is poor. Television medical dramas are the primary source of resuscitation knowledge. Deficiencies in healthcare professionals\\' knowledge of resuscitation ethics and outcomes may compromise resuscitation decisions. Educational initiatives to address deficiencies are necessary. Parties involved in discussion on resuscitation do not share the same knowledge base reducing the likelihood of meaningful discussion. Public misapprehensions surrounding resuscitation must be identified and corrected during discussion.

  7. Kif5 regulates mitochondrial movement, morphology, function and neuronal survival. (United States)

    Iworima, Diepiriye G; Pasqualotto, Bryce A; Rintoul, Gordon L


    Due to the unique architecture of neurons, trafficking of mitochondria throughout processes to regions of high energetic demand is critical to sustain neuronal health. It has been suggested that compromised mitochondrial trafficking may play a role in neurodegenerative diseases. We evaluated the consequences of disrupted kif5c-mediated mitochondrial trafficking on mitochondrial form and function in primary rat cortical neurons. Morphological changes in mitochondria appeared to be due to remodelling, a phenomenon distinct from mitochondrial fission, which resulted in punctate-shaped mitochondria. We also demonstrated that neurons displaying punctate mitochondria exhibited relatively decreased ROS and increased cellular ATP levels using ROS-sensitive GFP and ATP FRET probes, respectively. Somewhat unexpectedly, neurons overexpressing the dominant negative form of kif5c exhibited enhanced survival following excitotoxicity, suggesting that the impairment of mitochondrial trafficking conferred some form of neuroprotection. However, when neurons were exposed to H2O2, disruption of kif5c exacerbated cell death indicating that the effect on cell viability was dependent on the mode of toxicity. Our results suggest a novel role of kif5c. In addition to mediating mitochondrial transport, kif5c plays a role in the mechanism of regulating mitochondrial morphology. Our results also suggest that kif5c mediated mitochondrial dynamics may play an important role in regulating mitochondrial function and in turn cellular health. Moreover, our studies demonstrate an interesting interplay between the regulation of mitochondrial motility and morphology.

  8. Cardiac biomarkers in neonatal hypoxic ischaemia.

    LENUS (Irish Health Repository)

    Sweetman, D


    Following a perinatal hypoxic-ischaemic insult, term infants commonly develop cardiovascular dysfunction. Troponin-T, troponin-I and brain natriuretic peptide are sensitive indicators of myocardial compromise. The long-term effects of cardiovascular dysfunction on neurodevelopmental outcome following perinatal hypoxic ischaemia remain controversial. Follow-up studies are warranted to ensure optimal cardiac function in adulthood. CONCLUSION: Cardiac biomarkers may improve the diagnosis of myocardial injury, help guide management, estimate mortality risk and may also aid in longterm neurodevelopmental outcome prediction following neonatal hypoxic-ischaemia.

  9. Loss of mitochondrial exo/endonuclease EXOG affects mitochondrial respiration and induces ROS-mediated cardiomyocyte hypertrophy. (United States)

    Tigchelaar, Wardit; Yu, Hongjuan; de Jong, Anne Margreet; van Gilst, Wiek H; van der Harst, Pim; Westenbrink, B Daan; de Boer, Rudolf A; Silljé, Herman H W


    Recently, a locus at the mitochondrial exo/endonuclease EXOG gene, which has been implicated in mitochondrial DNA repair, was associated with cardiac function. The function of EXOG in cardiomyocytes is still elusive. Here we investigated the role of EXOG in mitochondrial function and hypertrophy in cardiomyocytes. Depletion of EXOG in primary neonatal rat ventricular cardiomyocytes (NRVCs) induced a marked increase in cardiomyocyte hypertrophy. Depletion of EXOG, however, did not result in loss of mitochondrial DNA integrity. Although EXOG depletion did not induce fetal gene expression and common hypertrophy pathways were not activated, a clear increase in ribosomal S6 phosphorylation was observed, which readily explains increased protein synthesis. With the use of a Seahorse flux analyzer, it was shown that the mitochondrial oxidative consumption rate (OCR) was increased 2.4-fold in EXOG-depleted NRVCs. Moreover, ATP-linked OCR was 5.2-fold higher. This increase was not explained by mitochondrial biogenesis or alterations in mitochondrial membrane potential. Western blotting confirmed normal levels of the oxidative phosphorylation (OXPHOS) complexes. The increased OCR was accompanied by a 5.4-fold increase in mitochondrial ROS levels. These increased ROS levels could be normalized with specific mitochondrial ROS scavengers (MitoTEMPO, mnSOD). Remarkably, scavenging of excess ROS strongly attenuated the hypertrophic response. In conclusion, loss of EXOG affects normal mitochondrial function resulting in increased mitochondrial respiration, excess ROS production, and cardiomyocyte hypertrophy.

  10. What Is Mitochondrial DNA? (United States)

    ... DNA What is mitochondrial DNA? What is mitochondrial DNA? Although most DNA is packaged in chromosomes within ... proteins. For more information about mitochondria and mitochondrial DNA: Molecular Expressions, a web site from the Florida ...

  11. Cardiac Rehabilitation (United States)

    ... your risk of future heart problems, and to improve your health and quality of life. Cardiac rehabilitation programs increase ... exercise routine at home or at a local gym. You may also continue to ... health concerns. Education about nutrition, lifestyle and weight loss ...

  12. Cardiolipin and mitochondrial cristae organization. (United States)

    Ikon, Nikita; Ryan, Robert O


    A fundamental question in cell biology, under investigation for over six decades, is the structural organization of mitochondrial cristae. Long known to harbor electron transport chain proteins, crista membrane integrity is key to establishment of the proton gradient that drives oxidative phosphorylation. Visualization of cristae morphology by electron microscopy/tomography has provided evidence that cristae are tube-like extensions of the mitochondrial inner membrane (IM) that project into the matrix space. Reconciling ultrastructural data with the lipid composition of the IM provides support for a continuously curved cylindrical bilayer capped by a dome-shaped tip. Strain imposed by the degree of curvature is relieved by an asymmetric distribution of phospholipids in monolayer leaflets that comprise cristae membranes. The signature mitochondrial lipid, cardiolipin (~18% of IM phospholipid mass), and phosphatidylethanolamine (34%) segregate to the negatively curved monolayer leaflet facing the crista lumen while the opposing, positively curved, matrix-facing monolayer leaflet contains predominantly phosphatidylcholine. Associated with cristae are numerous proteins that function in distinctive ways to establish and/or maintain their lipid repertoire and structural integrity. By combining unique lipid components with a set of protein modulators, crista membranes adopt and maintain their characteristic morphological and functional properties. Once established, cristae ultrastructure has a direct impact on oxidative phosphorylation, apoptosis, fusion/fission as well as diseases of compromised energy metabolism.

  13. Nutritional Status and Cardiac Autophagy

    Directory of Open Access Journals (Sweden)

    Jihyun Ahn


    Full Text Available Autophagy is necessary for the degradation of long-lasting proteins and nonfunctional organelles, and is activated to promote cellular survival. However, overactivation of autophagy may deplete essential molecules and organelles responsible for cellular survival. Lifelong calorie restriction by 40% has been shown to increase the cardiac expression of autophagic markers, which suggests that it may have a cardioprotective effect by decreasing oxidative damage brought on by aging and cardiovascular diseases. Although cardiac autophagy is critical to regulating protein quality and maintaining cellular function and survival, increased or excessive autophagy may have deleterious effects on the heart under some circumstances, including pressure overload-induced heart failure. The importance of autophagy has been shown in nutrient supply and preservation of energy in times of limitation, such as ischemia. Some studies have suggested that a transition from obesity to metabolic syndrome may involve progressive changes in myocardial inflammation, mitochondrial dysfunction, fibrosis, apoptosis, and myocardial autophagy.

  14. Roles of mitochondrial fragmentation and reactive oxygen species in mitochondrial dysfunction and myocardial insulin resistance

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Tomoyuki [Internal Medicine III, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu 431-3192 (Japan); Saotome, Masao, E-mail: [Internal Medicine III, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu 431-3192 (Japan); Nobuhara, Mamoru; Sakamoto, Atsushi; Urushida, Tsuyoshi; Katoh, Hideki; Satoh, Hiroshi [Internal Medicine III, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu 431-3192 (Japan); Funaki, Makoto [Clinical Research Center for Diabetes, Tokushima University Hospital, 2-50-1 Kuramoto-cho, Tokushima 770-8503 (Japan); Hayashi, Hideharu [Internal Medicine III, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu 431-3192 (Japan)


    Purpose: Evidence suggests an association between aberrant mitochondrial dynamics and cardiac diseases. Because myocardial metabolic deficiency caused by insulin resistance plays a crucial role in heart disease, we investigated the role of dynamin-related protein-1 (DRP1; a mitochondrial fission protein) in the pathogenesis of myocardial insulin resistance. Methods and Results: DRP1-expressing H9c2 myocytes, which had fragmented mitochondria with mitochondrial membrane potential (ΔΨ{sub m}) depolarization, exhibited attenuated insulin signaling and 2-deoxy-D-glucose (2-DG) uptake, indicating insulin resistance. Treatment of the DRP1-expressing myocytes with Mn(III)tetrakis(1-methyl-4-pyridyl)porphyrin pentachloride (TMPyP) significantly improved insulin resistance and mitochondrial dysfunction. When myocytes were exposed to hydrogen peroxide (H{sub 2}O{sub 2}), they increased DRP1 expression and mitochondrial fragmentation, resulting in ΔΨ{sub m} depolarization and insulin resistance. When DRP1 was suppressed by siRNA, H{sub 2}O{sub 2}-induced mitochondrial dysfunction and insulin resistance were restored. Our results suggest that a mutual enhancement between DRP1 and reactive oxygen species could induce mitochondrial dysfunction and myocardial insulin resistance. In palmitate-induced insulin-resistant myocytes, neither DRP1-suppression nor TMPyP restored the ΔΨ{sub m} depolarization and impaired 2-DG uptake, however they improved insulin signaling. Conclusions: A mutual enhancement between DRP1 and ROS could promote mitochondrial dysfunction and inhibition of insulin signal transduction. However, other mechanisms, including lipid metabolite-induced mitochondrial dysfunction, may be involved in palmitate-induced insulin resistance. - Highlights: • DRP1 promotes mitochondrial fragmentation and insulin-resistance. • A mutual enhancement between DRP1 and ROS ipromotes insulin-resistance. • Palmitate increases DRP1 expression and induces insulin

  15. Protection of anisodamine on the mitochondrial injury induced by oxidative stress in swine with cardiac arrest%山莨菪碱对心搏骤停猪氧化应激致心肌线粒体损伤的保护作用

    Institute of Scientific and Technical Information of China (English)

    刘亚华; 张杰; 代正; 周满红; 李玉华; 尹雪莲; 张维; 沈洪


    ).Methods Twenty-three healthy male swine were divided into three groups using random digits table:sham group (n =5),epinephrine group (n =9),and anisodamine group (n =9).The CA model was reproduced by alternating current.Blood samples were collected before CA,8 minutes after CA,and 0 minute,30 minutes,24 hours after recovery of spontaneous circulation (ROSC),and hearts were harvested at 24 hours after ROSC.The content of malondialdehyde (MDA) and the enzyme activity of superoxide dismutase (SOD) were analyzed by spectrophotography,the cardiac ATP content was assayed by high performance liquid chromatography,the generation of reactive oxygen species (ROS) was detected by laser confocal microscope,and the myocardial ultrastructures were observed with transmission electron microscope to assess mitochondrial damage score.Results At 30 minutes and 24 hours after ROSC,plasma MDA level (μmol/L) of anisodamine group was lower than that of epinephrine group (30 minutes:43.38 ± 8.12 vs.55.47 ± 10.97,24 hours:29.96 ± 6.04 vs.37.87 ± 7.85,both P<0.05).Compared with epinephrine group,the cardiac SOD activity (U/mg) and ATP content (μmol/g) of anisodamine group were elevated (SOD:1.35 ± 0.50 vs.0.54 ± 0.19,ATP:4.17 ± 1.06 vs.2.95 ±0.94,P<0.01 and P<0.05),and the mitochondrial ROS level (RFU) was lowered (88.00 ± 17.67 vs.107.00 ± 21.35,P<0.05).Although the cardiac MDA content (μmol/mg) was also reduced,but the difference between two resuscitation groups showed no statistical significance (16.66 ± 2.89 vs.19.28 ± 3.90,P>0.05).Using electron microscope,in epinephrine group disordered arrangement of cardiac myocyte arrangement was observed,and the mitochondrial alignment and morphology were significantly different from the sham group (mitochondrial damage score:0.41 ± 0.08 vs.0.12 ± 0.01,P<0.01).The level of mitochondrial injury in anisodamine group was milder than that of epinephrine group (mitochondrial damage score:0.21 ±0.05 vs.0.41 ±0.08,P<0.05).Conclusion

  16. Kinetics and specificity of paternal mitochondrial elimination in Caenorhabditis elegans. (United States)

    Wang, Yang; Zhang, Yi; Chen, Lianwan; Liang, Qian; Yin, Xiao-Ming; Miao, Long; Kang, Byung-Ho; Xue, Ding


    In most eukaryotes, mitochondria are inherited maternally. The autophagy process is critical for paternal mitochondrial elimination (PME) in Caenorhabditis elegans, but how paternal mitochondria, but not maternal mitochondria, are selectively targeted for degradation is poorly understood. Here we report that mitochondrial dynamics have a profound effect on PME. A defect in fission of paternal mitochondria delays PME, whereas a defect in fusion of paternal mitochondria accelerates PME. Surprisingly, a defect in maternal mitochondrial fusion delays PME, which is reversed by a fission defect in maternal mitochondria or by increasing maternal mitochondrial membrane potential using oligomycin. Electron microscopy and tomography analyses reveal that a proportion of maternal mitochondria are compromised when they fail to fuse normally, leading to their competition for the autophagy machinery with damaged paternal mitochondria and delayed PME. Our study indicates that mitochondrial dynamics play a critical role in regulating both the kinetics and the specificity of PME.

  17. Kinetics and specificity of paternal mitochondrial elimination in Caenorhabditis elegans (United States)

    Wang, Yang; Zhang, Yi; Chen, Lianwan; Liang, Qian; Yin, Xiao-Ming; Miao, Long; Kang, Byung-Ho; Xue, Ding


    In most eukaryotes, mitochondria are inherited maternally. The autophagy process is critical for paternal mitochondrial elimination (PME) in Caenorhabditis elegans, but how paternal mitochondria, but not maternal mitochondria, are selectively targeted for degradation is poorly understood. Here we report that mitochondrial dynamics have a profound effect on PME. A defect in fission of paternal mitochondria delays PME, whereas a defect in fusion of paternal mitochondria accelerates PME. Surprisingly, a defect in maternal mitochondrial fusion delays PME, which is reversed by a fission defect in maternal mitochondria or by increasing maternal mitochondrial membrane potential using oligomycin. Electron microscopy and tomography analyses reveal that a proportion of maternal mitochondria are compromised when they fail to fuse normally, leading to their competition for the autophagy machinery with damaged paternal mitochondria and delayed PME. Our study indicates that mitochondrial dynamics play a critical role in regulating both the kinetics and the specificity of PME. PMID:27581092

  18. Cardiac transplant in young female patient diagnosed with diffuse systemic sclerosis. (United States)

    Bennasar, Guillermo; Carlevaris, Leandro; Secco, Anastasia; Romanini, Felix; Mamani, Marta


    Systemic sclerosis (SS) in a multifactorial and systemic, chronic, autoimmune disease that affects the connective tissue. We present this clinical case given the low prevalence of diffuse SS with early and progressive cardiac compromise in a young patient, and treatment with cardiac transplantation.

  19. Cardiac Calcification

    Directory of Open Access Journals (Sweden)

    Morteza Joorabian


    Full Text Available There is a spectrum of different types of cardiac"ncalcifications with the importance and significance"nof each type of cardiac calcification, especially"ncoronary artery calcification. Radiologic detection of"ncalcifications within the heart is quite common. The"namount of coronary artery calcification correlates"nwith the severity of coronary artery disease (CAD."nCalcification of the aortic or mitral valve may indicate"nhemodynamically significant valvular stenosis."nMyocardial calcification is a sign of prior infarction,"nwhile pericardial calcification is strongly associated"nwith constrictive pericarditis. A spectrum of different"ntypes of cardiac calcifications (linear, annular,"ncurvilinear,... could be seen in chest radiography and"nother imaging modalities. So a carful inspection for"ndetection and reorganization of these calcifications"nshould be necessary. Numerous modalities exist for"nidentifying coronary calcification, including plain"nradiography, fluoroscopy, intravascular ultrasound,"nMRI, echocardiography, and conventional, helical and"nelectron-beam CT (EBCT. Coronary calcifications"ndetected on EBCT or helical CT can be quantifie,"nand a total calcification score (Cardiac Calcification"nScoring may be calculated. In an asymptomatic"npopulation and/or patients with concomitant risk"nfactors like diabetes mellitus, determination of the"npresence of coronary calcifications identifies the"npatients at risk for future myocardial infarction and"ncoronary artery disease. In patients without coronary"ncalcifications, future cardiovascular events could"nbe excluded. Therefore, detecting and recognizing"ncalcification related to the heart on chest radiography"nand other imaging modalities such as fluoroscopy, CT"nand echocardiography may have important clinical"nimplications.

  20. Modeling mitochondrial bioenergetics with integrated volume dynamics.

    Directory of Open Access Journals (Sweden)

    Jason N Bazil


    Full Text Available Mathematical models of mitochondrial bioenergetics provide powerful analytical tools to help interpret experimental data and facilitate experimental design for elucidating the supporting biochemical and physical processes. As a next step towards constructing a complete physiologically faithful mitochondrial bioenergetics model, a mathematical model was developed targeting the cardiac mitochondrial bioenergetic based upon previous efforts, and corroborated using both transient and steady state data. The model consists of several modified rate functions of mitochondrial bioenergetics, integrated calcium dynamics and a detailed description of the K(+-cycle and its effect on mitochondrial bioenergetics and matrix volume regulation. Model simulations were used to fit 42 adjustable parameters to four independent experimental data sets consisting of 32 data curves. During the model development, a certain network topology had to be in place and some assumptions about uncertain or unobserved experimental factors and conditions were explicitly constrained in order to faithfully reproduce all the data sets. These realizations are discussed, and their necessity helps contribute to the collective understanding of the mitochondrial bioenergetics.

  1. Modeling mitochondrial bioenergetics with integrated volume dynamics. (United States)

    Bazil, Jason N; Buzzard, Gregery T; Rundell, Ann E


    Mathematical models of mitochondrial bioenergetics provide powerful analytical tools to help interpret experimental data and facilitate experimental design for elucidating the supporting biochemical and physical processes. As a next step towards constructing a complete physiologically faithful mitochondrial bioenergetics model, a mathematical model was developed targeting the cardiac mitochondrial bioenergetic based upon previous efforts, and corroborated using both transient and steady state data. The model consists of several modified rate functions of mitochondrial bioenergetics, integrated calcium dynamics and a detailed description of the K(+)-cycle and its effect on mitochondrial bioenergetics and matrix volume regulation. Model simulations were used to fit 42 adjustable parameters to four independent experimental data sets consisting of 32 data curves. During the model development, a certain network topology had to be in place and some assumptions about uncertain or unobserved experimental factors and conditions were explicitly constrained in order to faithfully reproduce all the data sets. These realizations are discussed, and their necessity helps contribute to the collective understanding of the mitochondrial bioenergetics.

  2. Iron insufficiency compromises motor neurons and their mitochondrial function in Irp2-null mice.

    Directory of Open Access Journals (Sweden)

    Suh Young Jeong

    Full Text Available Genetic ablation of Iron Regulatory Protein 2 (Irp2, Ireb2, which post-transcriptionally regulates iron metabolism genes, causes a gait disorder in mice that progresses to hind-limb paralysis. Here we have demonstrated that misregulation of iron metabolism from loss of Irp2 causes lower motor neuronal degeneration with significant spinal cord axonopathy. Mitochondria in the lumbar spinal cord showed significantly decreased Complex I and II activities, and abnormal morphology. Lower motor neurons appeared to be the most adversely affected neurons, and we show that functional iron starvation due to misregulation of iron import and storage proteins, including transferrin receptor 1 and ferritin, may have a causal role in disease. We demonstrated that two therapeutic approaches were beneficial for motor neuron survival. First, we activated a homologous protein, IRP1, by oral Tempol treatment and found that axons were partially spared from degeneration. Secondly, we genetically decreased expression of the iron storage protein, ferritin, to diminish functional iron starvation. These data suggest that functional iron deficiency may constitute a previously unrecognized molecular basis for degeneration of motor neurons in mice.

  3. Iron insufficiency compromises motor neurons and their mitochondrial function in Irp2-null mice

    KAUST Repository

    Jeong, Suh Young


    Genetic ablation of Iron Regulatory Protein 2 (Irp2, Ireb2), which post-transcriptionally regulates iron metabolism genes, causes a gait disorder in mice that progresses to hind-limb paralysis. Here we have demonstrated that misregulation of iron metabolism from loss of Irp2 causes lower motor neuronal degeneration with significant spinal cord axonopathy. Mitochondria in the lumbar spinal cord showed significantly decreased Complex I and II activities, and abnormal morphology. Lower motor neurons appeared to be the most adversely affected neurons, and we show that functional iron starvation due to misregulation of iron import and storage proteins, including transferrin receptor 1 and ferritin, may have a causal role in disease. We demonstrated that two therapeutic approaches were beneficial for motor neuron survival. First, we activated a homologous protein, IRP1, by oral Tempol treatment and found that axons were partially spared from degeneration. Secondly, we genetically decreased expression of the iron storage protein, ferritin, to diminish functional iron starvation. These data suggest that functional iron deficiency may constitute a previously unrecognized molecular basis for degeneration of motor neurons in mice.

  4. Mitochondrial DNA Alterations and Reduced Mitochondrial Function in Aging


    Hebert, Sadie L.; Lanza, Ian R.; Nair, K. Sreekumaran


    Oxidative damage to mitochondrial DNA increases with aging. This damage has the potential to affect mitochondrial DNA replication and transcription which could alter the abundance or functionality of mitochondrial proteins. This review describes mitochondrial DNA alterations and changes in mitochondrial function that occur with aging. Age-related alterations in mitochondrial DNA as a possible contributor to the reduction in mitochondrial function are discussed.

  5. 40 CFR 13.25 - Standards for compromise. (United States)


    ... enforced collection proceedings. In evaluating the acceptability of the offer, the Administrator may... under State and Federal law in determining the Government's ability to enforce collection. (2) Municipal... proceedings. (b) EPA may compromise a claim, or recommend acceptance of a compromise to DOJ, where there...

  6. 26 CFR 300.3 - Offer to compromise fee. (United States)


    ... taxpayer if the offer is accepted, rejected, withdrawn, or returned as nonprocessable after acceptance for... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Offer to compromise fee. 300.3 Section 300.3... ADMINISTRATION USER FEES § 300.3 Offer to compromise fee. (a) Applicability. This section applies to...

  7. MELAS Syndrome with Cardiac Involvement: A Multimodality Imaging Approach

    Directory of Open Access Journals (Sweden)

    Sara Seitun


    Full Text Available A 49-year-old man presented with chest pain, dyspnea, and lactic acidosis. Left ventricular hypertrophy and myocardial fibrosis were detected. The sequencing of mitochondrial genome (mtDNA revealed the presence of A to G mtDNA point mutation at position 3243 (m.3243A>G in tRNALeu(UUR gene. Diagnosis of cardiac involvement in a patient with Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like episodes syndrome (MELAS was made. Due to increased risk of sudden cardiac death, cardioverter defibrillator was implanted.

  8. Multisite Tissue Oxygenation Monitoring Indicates Organ-Specific Flow Distribution and Oxygen Delivery Related to Low Cardiac Output in Preterm Infants With Clinical Sepsis

    NARCIS (Netherlands)

    van der Laan, Michelle E.; Roofthooft, Marcus T. R.; Fries, Marian W. A.; Schat, Trijntje E.; Bos, Arend F.; Berger, Rolf M. F.; Kooi, Elisabeth M. W.


    Objectives: Cardiac output may be compromised in preterm infants with sepsis. Whether low cardiac output is associated with low tissue oxygen supply in these patients is unclear. The aim of the current study was to assess the association between cardiac output, assessed by echocardiography, and tiss

  9. Overexpression of Catalase Diminishes Oxidative Cysteine Modifications of Cardiac Proteins.

    Directory of Open Access Journals (Sweden)

    Chunxiang Yao

    Full Text Available Reactive protein cysteine thiolates are instrumental in redox regulation. Oxidants, such as hydrogen peroxide (H2O2, react with thiolates to form oxidative post-translational modifications, enabling physiological redox signaling. Cardiac disease and aging are associated with oxidative stress which can impair redox signaling by altering essential cysteine thiolates. We previously found that cardiac-specific overexpression of catalase (Cat, an enzyme that detoxifies excess H2O2, protected from oxidative stress and delayed cardiac aging in mice. Using redox proteomics and systems biology, we sought to identify the cysteines that could play a key role in cardiac disease and aging. With a 'Tandem Mass Tag' (TMT labeling strategy and mass spectrometry, we investigated differential reversible cysteine oxidation in the cardiac proteome of wild type and Cat transgenic (Tg mice. Reversible cysteine oxidation was measured as thiol occupancy, the ratio of total available versus reversibly oxidized cysteine thiols. Catalase overexpression globally decreased thiol occupancy by ≥1.3 fold in 82 proteins, including numerous mitochondrial and contractile proteins. Systems biology analysis assigned the majority of proteins with differentially modified thiols in Cat Tg mice to pathways of aging and cardiac disease, including cellular stress response, proteostasis, and apoptosis. In addition, Cat Tg mice exhibited diminished protein glutathione adducts and decreased H2O2 production from mitochondrial complex I and II, suggesting improved function of cardiac mitochondria. In conclusion, our data suggest that catalase may alleviate cardiac disease and aging by moderating global protein cysteine thiol oxidation.

  10. Non-contact left ventricular endocardial mapping for cardiac resynchronisation therapy: a “slow conduction” towards the fast solution (United States)

    Bella, P Della; Carbucicchio, C


    Cardiac resynchronisation therapy can help to improve left ventricular function in patients with heart failure, but only if those regions of myocardium which are mostly compromised by electromechanical desynchronisation can be identified and effectively stimulated PMID:15084532

  11. Non-contact left ventricular endocardial mapping for cardiac resynchronisation therapy: a "slow conduction" towards the fast solution. (United States)

    Della Bella, P; Carbucicchio, C


    Cardiac resynchronisation therapy can help to improve left ventricular function in patients with heart failure, but only if those regions of myocardium which are mostly compromised by electromechanical desynchronisation can be identified and effectively stimulated.

  12. Erythropoietin treatment enhances muscle mitochondrial capacity in humans

    DEFF Research Database (Denmark)

    Plenge, Ulla; Belhage, Bo; Guadalupe-Grau, Amelia;


    Erythropoietin (Epo) treatment has been shown to induce mitochondrial biogenesis in cardiac muscle along with enhanced mitochondrial capacity in mice. We hypothesized that recombinant human Epo (rhEpo) treatment enhances skeletal muscle mitochondrial oxidative phosphorylation (OXPHOS) capacity...... in humans. In six healthy volunteers rhEpo was administered by sub-cutaneous injection over 8 weeks with oral iron (100 mg) supplementation taken daily. Mitochondrial OXPHOS was quantified by high-resolution respirometry in saponin-permeabilized muscle fibers obtained from biopsies of the vastus lateralis...... before and after rhEpo treatment. OXPHOS was determined with the mitochondrial complex I substrates malate, glutamate, pyruvate, and complex II substrate succinate in the presence of saturating ADP concentrations, while maximal electron transport capacity (ETS) was assessed by addition of an uncoupler...

  13. Compromised data from social media to big data

    CERN Document Server

    Redden, Joanna; Langlois, Ganaele


    There has been a data rush in the past decade brought about by online communication and, in particular, social media (Facebook, Twitter, Youtube, among others), which promises a new age of digital enlightenment. But social data is compromised: it is being seized by specific economic interests, it leads to a fundamental shift in the relationship between research and the public good, and it fosters new forms of control and surveillance. Compromised Data: From Social Media to Big Data explores how we perform critical research within a compromised social data framework. The expert, international l

  14. Characteristics of mitochondrial calpains. (United States)

    Ozaki, Taku; Tomita, Hiroshi; Tamai, Makoto; Ishiguro, Sei-Ichi


    Calpains are considered to be cytoplasmic enzymes, although several studies have shown that calpain-like protease activities also exist in mitochondria. We partially purified mitochondrial calpain from swine liver mitochondria and characterized. Only one type of mitochondrial calpain was detected by the column chromatographies. The mitochondrial calpain was stained with anti-mu-calpain and calpain small subunit antibodies. The susceptibility of mitochondrial calpain to calpain inhibitors and the optimum pH differ from those of cytosolic mu- and m-calpains. The Ca(2+)-dependency of mitochondrial calpain was similar to that of cytosolic mu-calpain. Therefore, we named the protease mitochondrial mu-like calpain. In zymogram analysis, two types of caseinolytic enzymes existed in mitochondria and showed different mobilities from cytosolic mu- and m-calpains. The upper major band was stained with anti-mu-calpain and calpain small subunit antibodies (mitochondrial calpain I, mitochondrial mu-like calpain). The lower band was stained only with anti-calpain small subunit antibody (mitochondrial calpain II, unknown mitochondrial calpain). Calpastatin was not detected in mitochondrial compartments. The mitochondrial calpain processed apoptosis-inducing factor (AIF) to truncated AIF (tAIF), releasing tAIF into the intermembrane space. These results indicate that mitochondrial calpain, which differs from mu- and m-calpains, seems to be a ubiquitous calpain and may play a role in mitochondrial apoptotic signalling.

  15. Diabetes-associated dysregulation of O-GlcNAcylation in rat cardiac mitochondria (United States)

    Banerjee, Partha S.; Ma, Junfeng; Hart, Gerald W.


    Elevated mitochondrial O-GlcNAcylation caused by hyperglycemia, as occurs in diabetes, significantly contributes to mitochondrial dysfunction and to diabetic cardiomyopathy. However, little is known about the enzymology of mitochondrial O-GlcNAcylation. Herein, we investigated the enzymes responsible for cycling O-GlcNAc on mitochondrial proteins and studied the mitochondrial transport of UDP-GlcNAc. Analyses of purified rat heart mitochondria from normal and streptozocin-treated diabetic rats show increased mitochondrial O-GlcNAc transferase (OGT) and a concomitant decrease in the mito-specific O-GlcNAcase (OGA). Strikingly, OGT is mislocalized in cardiac mitochondria from diabetic rats. Interaction of OGT and complex IV observed in normal rat heart mitochondria is visibly reduced in diabetic samples, where OGT is mislocalized to the matrix. Live cell OGA activity assays establish the presence of O-GlcNAcase within the mitochondria. Furthermore, we establish that the inner mitochondrial membrane transporter, pyrimidine nucleotide carrier, transports UDP-GlcNAc from the cytosol to the inside of the mitochondria. Knockdown of this transporter substantially lowers mitochondrial O-GlcNAcylation. Inhibition of OGT or OGA activity within neonatal rat cardiomyocytes significantly affects energy production, mitochondrial membrane potential, and mitochondrial oxygen consumption. These data suggest that cardiac mitochondria not only have robust O-GlcNAc cycling, but also that dysregulation of O-GlcNAcylation likely plays a key role in mitochondrial dysfunction associated with diabetes. PMID:25918408

  16. Mitochondrial calcium overload is a key determinant in heart failure. (United States)

    Santulli, Gaetano; Xie, Wenjun; Reiken, Steven R; Marks, Andrew R


    Calcium (Ca2+) released from the sarcoplasmic reticulum (SR) is crucial for excitation-contraction (E-C) coupling. Mitochondria, the major source of energy, in the form of ATP, required for cardiac contractility, are closely interconnected with the SR, and Ca2+ is essential for optimal function of these organelles. However, Ca2+ accumulation can impair mitochondrial function, leading to reduced ATP production and increased release of reactive oxygen species (ROS). Oxidative stress contributes to heart failure (HF), but whether mitochondrial Ca2+ plays a mechanistic role in HF remains unresolved. Here, we show for the first time, to our knowledge, that diastolic SR Ca2+ leak causes mitochondrial Ca2+ overload and dysfunction in a murine model of postmyocardial infarction HF. There are two forms of Ca2+ release channels on cardiac SR: type 2 ryanodine receptors (RyR2s) and type 2 inositol 1,4,5-trisphosphate receptors (IP3R2s). Using murine models harboring RyR2 mutations that either cause or inhibit SR Ca2+ leak, we found that leaky RyR2 channels result in mitochondrial Ca2+ overload, dysmorphology, and malfunction. In contrast, cardiac-specific deletion of IP3R2 had no major effect on mitochondrial fitness in HF. Moreover, genetic enhancement of mitochondrial antioxidant activity improved mitochondrial function and reduced posttranslational modifications of RyR2 macromolecular complex. Our data demonstrate that leaky RyR2, but not IP3R2, channels cause mitochondrial Ca2+ overload and dysfunction in HF.

  17. 45 CFR 30.22 - Bases for compromise. (United States)


    ... income; (iii) Inheritance prospects; (iv) The possibility that assets have been concealed or improperly... other property will bring at a forced sale. (ii) A compromise effected under this section should be...

  18. 41 CFR 105-55.020 - Bases for compromise. (United States)


    ... following: (1) Age and health of the debtor. (2) Present and potential income. (3) Inheritance prospects. (4... sale in determining the Government's ability to enforce collection. A compromise effected under...

  19. Early detection of myocardial dysfunction in children with mitochondrial disease: An ultrasound and two-dimensional strain echocardiography study

    NARCIS (Netherlands)

    Marcus, K.A.; Barends, M.; Morava, E.; Feuth, T.; Korte, C.L. de; Kapusta, L.


    BACKGROUND: Myocardial dysfunction in children diagnosed with mitochondrial disease is an ominous sign and has been associated with substantial increased mortality rates. Early detection of cardiac involvement would therefore be desirable. Two dimensional strain echocardiography (2DSTE) has proven t

  20. Cardiac MRI in Athletes

    NARCIS (Netherlands)

    Luijkx, T.


    Cardiac magnetic resonance imaging (CMR) is often used in athletes to image cardiac anatomy and function and is increasingly requested in the context of screening for pathology that can cause sudden cardiac death (SCD). In this thesis, patterns of cardiac adaptation to sports are investigated with C

  1. Preserved recovery of cardiac function following ischemia-reperfusion in mice lacking SIRT3. (United States)

    Koentges, Christoph; Pfeil, Katharina; Meyer-Steenbuck, Maximilian; Lother, Achim; Hoffmann, Michael M; Odening, Katja E; Hein, Lutz; Bode, Christoph; Bugger, Heiko


    Lack of the mitochondrial deacetylase sirtuin 3 (SIRT3) impairs mitochondrial function and increases the susceptibility to induction of the mitochondrial permeability transition pore. Because these alterations contribute to myocardial ischemia-reperfusion (IR) injury, we hypothesized that SIRT3 deficiency may increase cardiac injury following myocardial IR. Hearts of 10-week-old mice were perfused in the isolated working mode and subjected to 17.5 min of global no-flow ischemia, followed by 30 min of reperfusion. Measurements before ischemia revealed a decrease in cardiac power (-20%) and rate pressure product (-15%) in SIRT3(-/-) mice. Mitochondrial state 3 respiration (-15%), ATP synthesis (-39%), and ATP/O ratios (-29%) were decreased in hearts of SIRT3(-/-) mice. However, percent recovery of cardiac power (WT 94% ± 9%; SIRT3(-/-) 89% ± 9%) and rate pressure product (WT 89% ± 16%; SIRT3(-/-) 96% ± 3%) following IR was similar in both groups. Myocardial infarct size was not increased in SIRT3(-/-) mice following permanent ligation of the left anterior descending coronary artery (LAD). Left ventricular pressure and dP/dtmax, and mitochondrial respiration and ATP synthesis were not different between groups following LAD ligation. Thus, despite pre-existing defects in cardiac function and mitochondrial respiratory capacity in SIRT3(-/-) mice, SIRT3 deficiency does not additionally impair cardiac function following IR or following myocardial infarction.

  2. Mitochondrial biogenesis and turnover. (United States)

    Diaz, Francisca; Moraes, Carlos T


    Mitochondrial biogenesis is a complex process involving the coordinated expression of mitochondrial and nuclear genes, the import of the products of the latter into the organelle and turnover. The mechanisms associated with these events have been intensively studied in the last 20 years and our understanding of their details is much improved. Mitochondrial biogenesis requires the participation of calcium signaling that activates a series of calcium-dependent protein kinases that in turn activate transcription factors and coactivators such as PGC-1alpha that regulates the expression of genes coding for mitochondrial components. In addition, mitochondrial biogenesis involves the balance of mitochondrial fission-fusion. Mitochondrial malfunction or defects in any of the many pathways involved in mitochondrial biogenesis can lead to degenerative diseases and possibly play an important part in aging.

  3. Indications and contraindications of dental implants in medically compromised patients: update. (United States)

    Gómez-de Diego, Rafael; Mang-de la Rosa, María del Rocío; Romero-Pérez, María-Jesús; Cutando-Soriano, Antonio; López-Valverde-Centeno, Antonio


    The aim of this study was to review the current scientific literature in order to analyse the indications and contraindications of dental implants in medically compromised patients. A reference research was carried out on PubMed using the key words "implant" AND (oral OR dental) AND (systemic disease OR medically compromised), in articles published between 1993 and 2013. The inclusion criteria were the following: clinical studies in which, at least, 10 patients were treated, consensus articles, reviewed articles and meta-analysis performed in humans treated with dental implants, and which included the disease diagnosis. A total of 64 articles were found, from which 16 met the inclusion criteria. Cardiac systemic diseases, diabetic endocrine pathologies or controlled metabolic disorders do not seem to be a total or partial contraindication to the placement of dental implants. Tobacco addiction, and head and neck radiotherapy are correlated to a higher loss of dental implants. Patients suffering from osteoporosis undergoing biphosphonates therapy show an increased risk of developing bone necrosis after an oral surgery, especially if the drugs are administered intravenously or they are associated to certain concomitant medication.

  4. MicroRNAs regulate mitochondrial apoptotic pathway in myocardial ischemia-reperfusion-injury. (United States)

    Makhdoumi, Pouran; Roohbakhsh, Ali; Karimi, Gholamreza


    MicroRNAs (miRNAs) are small non-coding RNAs that act as post-transcriptional gene regulators. They are involved in the pathogenesis of different disorders including heart diseases. MiRNAs contribute to ischemia/reperfusion injury (I/RI) by altering numerous key signaling elements. Together with alterations in the various potential signaling pathways, modification in miRNA expression has been suggested as a part of the response network following ischemia/reperfusion (I/R). In addition, cardiac mitochondrial homeostasis is closely associated with cardiac function and impairment of mitochondrial activity occurred after ischemia/reperfusion injury. MiRNAs play a key role in the regulation of mitochondrial apoptotic pathway and signaling proteins. In this review, we summarize the knowledge currently available regarding the molecular mechanisms of miRNA-regulated mitochondrial functions during ischemia/reperfusion injury. This regulation occurs in different stages of mitochondrial apoptosis pathway.

  5. Mitochondrial genes are altered in blood early in Alzheimer's disease. (United States)

    Lunnon, Katie; Keohane, Aoife; Pidsley, Ruth; Newhouse, Stephen; Riddoch-Contreras, Joanna; Thubron, Elisabeth B; Devall, Matthew; Soininen, Hikka; Kłoszewska, Iwona; Mecocci, Patrizia; Tsolaki, Magda; Vellas, Bruno; Schalkwyk, Leonard; Dobson, Richard; Malik, Afshan N; Powell, John; Lovestone, Simon; Hodges, Angela


    Although mitochondrial dysfunction is a consistent feature of Alzheimer's disease in the brain and blood, the molecular mechanisms behind these phenomena are unknown. Here we have replicated our previous findings demonstrating reduced expression of nuclear-encoded oxidative phosphorylation (OXPHOS) subunits and subunits required for the translation of mitochondrial-encoded OXPHOS genes in blood from people with Alzheimer's disease and mild cognitive impairment. Interestingly this was accompanied by increased expression of some mitochondrial-encoded OXPHOS genes, namely those residing closest to the transcription start site of the polycistronic heavy chain mitochondrial transcript (MT-ND1, MT-ND2, MT-ATP6, MT-CO1, MT-CO2, MT-C03) and MT-ND6 transcribed from the light chain. Further we show that mitochondrial DNA copy number was unchanged suggesting no change in steady-state numbers of mitochondria. We suggest that an imbalance in nuclear and mitochondrial genome-encoded OXPHOS transcripts may drive a negative feedback loop reducing mitochondrial translation and compromising OXPHOS efficiency, which is likely to generate damaging reactive oxygen species.

  6. Impaired mitochondrial function in human placenta with increased maternal adiposity. (United States)

    Mele, James; Muralimanoharan, Sribalasubashini; Maloyan, Alina; Myatt, Leslie


    The placenta plays a key role in regulation of fetal growth and development and in mediating in utero developmental programming. Obesity, which is associated with chronic inflammation and mitochondrial dysfunction in many tissues, exerts a programming effect in pregnancy. We determined the effect of increasing maternal adiposity and of fetal sex on placental ATP generation, mitochondrial biogenesis, expression of electron transport chain subunits, and mitochondrial function in isolated trophoblasts. Placental tissue was collected from women with prepregnancy BMI ranging from 18.5 to 45 following C-section at term with no labor. Increasing maternal adiposity was associated with excessive production of reactive oxygen species and a significant reduction in placental ATP levels in placentae with male and female fetuses. To explore the potential mechanism of placental mitochondrial dysfunction, levels of transcription factors regulating the expression of genes involved in electron transport and mitochondrial biogenesis were measured. Our in vitro studies showed significant reduction in mitochondrial respiration in cultured primary trophoblasts with increasing maternal obesity along with an abnormal metabolic flexibility of these cells. This reduction in placental mitochondrial respiration in pregnancies complicated by maternal obesity could compromise placental function and potentially underlie the increased susceptibility of these pregnancies to fetal demise in late gestation and to developmental programming.

  7. Strokes in mitochondrial diseases

    Directory of Open Access Journals (Sweden)

    N V Pizova


    Full Text Available It is suggested that mitochondrial diseases might be identified in 22—33% of cryptogenic stroke cases in young subjects. The incidence of mitochondrial disorders in patients with stroke is unknown; it is 0.8 to 7.2% according to the data of some authors. The paper gives data on the prevalence, pathogenesis, and clinical manifestations of mitochondrial diseases, such as mitochondrial encephalopathy, lactic acidosis, and stroke-like syndrome (MELAS and insulin-like episodes; myoclonic epilepsy and ragged-red fibers (MERRF syndrome, and Kearns-Sayre syndrome (sporadic multisystem mitochondrial pathology.

  8. Compromising positions: emergent neo-Fordisms and embedded gender contracts. (United States)

    Gottfried, H


    This paper adopts a regulation framework to chart the emergence of neo-Fordism as a flexible accumulation regime and mode of social regulation. Neo-Fordism relies on old Fordist principles as well as incorporating new models of emergent post-Fordisms; old and new social relationships, in their particular combination, specify the trajectory of national variants. I argue that Fordist bargains institutionalized the terms of a compromise between labour, capital and the state. These bargains embedded a male-breadwinner gender contract compromising women's positions and standardizing employment contracts around the needs, interests and authority of men. A focus on compromises and contracts makes visible the differentiated gender effects of work transformation in each country.

  9. Alchemy or Science? Compromising Archaeology in the Deep Sea (United States)

    Adams, Jonathan


    In the torrid debate between archaeology and treasure hunting, compromise is often suggested as the pragmatic solution, especially for archaeology carried out either in deep water or beyond the constraints that commonly regulate such activities in territorial seas. Both the wisdom and the need for such compromise have even been advocated by some archaeologists, particularly in forums such as the internet and conferences. This paper argues that such a compromise is impossible, not in order to fuel confrontation but simply because of the nature of any academic discipline. We can define what archaeology is in terms of its aims, theories, methods and ethics, so combining it with an activity founded on opposing principles must transform it into something else. The way forward for archaeology in the deep sea does not lie in a contradictory realignment of archaeology’s goals but in collaborative research designed to mesh with emerging national and regional research and management plans.

  10. Physically Compromised and Physically Talented Children in Northeastern Slovenia

    Directory of Open Access Journals (Sweden)

    Planinšec Jurij


    Full Text Available The aim of our research was to determine the share of physically compromised and physically talented children in northeastern Slovenia. The sample comprised 621 children aged nine to eleven years, among which there were 316 girls (M=10; SD=0.8 and 305 boys (M=10; SD=0.81. In order to assess their motor skills, seven different tests were used, mostly from Eurofit test battery, which covered explosive power, repetitive power balance, eye–hand coordination, speed of simple movements, whole body coordination, and endurance. The assessment was made for each physical fitness test separately. The cut-off points for determination of physically compromised and physically talented children were set at -1SD and +1SD, respectively. The results of all physical fitness tests showed that the share of physically compromised children exceeded ten percent for both genders. The largest number of boys and girls were physically compromised with regard to endurance and balance, respectively. On the other hand, boys proved to be most physically talented with regard to endurance, and girls with regard to explosive power. Gender differences were most obvious with regard to general endurance, as 21 per cent of the boys were physically compromised as opposed to 13 per cent of the girls. As for physical talent, we observed less gender-related differences. The results indicate increasing differences in physical fitness among children from northeastern Slovenia. The implementation of curricular and extracurricular sports activities should aim at reducing the number of physically compromised children. On the other hand, it would make sense to encourage physically talented children to get involved in organized forms of exercise.

  11. Mitochondria-targeted antioxidant mitotempo protects mitochondrial function against amyloid beta toxicity in primary cultured mouse neurons. (United States)

    Hu, Hongtao; Li, Mo


    Mitochondrial defects including excess reactive oxygen species (ROS) production and compromised ATP generation are featured pathology in Alzheimer's disease (AD). Amyloid beta (Aβ)-mediated mitochondrial ROS overproduction disrupts intra-neuronal Redox balance, in turn exacerbating mitochondrial dysfunction leading to neuronal injury. Previous studies have found the beneficial effects of mitochondria-targeted antioxidants in preventing mitochondrial dysfunction and neuronal injury in AD animal and cell models, suggesting that mitochondrial ROS scavengers hold promise for the treatment of this neurological disorder. In this study, we have determined that mitotempo, a novel mitochondria-targeted antioxidant protects mitochondrial function from the toxicity of Aβ in primary cultured neurons. Our results showed that Aβ-promoted mitochondrial superoxide production and neuronal lipid oxidation were significantly suppressed by the application of mitotempo. Moreover, mitotempo also demonstrated protective effects on mitochondrial bioenergetics evidenced by preserved mitochondrial membrane potential, cytochrome c oxidase activity as well as ATP production. In addition, the Aβ-induced mitochondrial DNA (mtDNA) depletion and decreased expression levels of mtDNA replication-related DNA polymerase gamma (DNA pol γ) and Twinkle were substantially mitigated by mitotempo. Therefore, our study suggests that elimination of excess mitochondrial ROS rescues mitochondrial function in Aβ-insulted neruons; and mitotempo has the potential to be a promising therapeutic agent to protect mitochondrial and neuronal function in AD.

  12. Endothelial Dysfunction in Resuscitated Cardiac Arrest (ENDO-RCA)

    DEFF Research Database (Denmark)

    Meyer, Anna Sina P; Ostrowski, Sisse R; Kjaergaard, Jesper;


    BACKGROUND: Morbidity and mortality following initial survival of cardiac arrest remain high despite great efforts to improve resuscitation techniques and post-resuscitation care, in part due to the ischemia-reperfusion injury secondary to the restoration of the blood circulation. Patients...... resuscitated from cardiac arrest display evidence of endothelial injury and coagulopathy (hypocoagulability, hyperfibrinolysis), which in associated with poor outcome. Recent randomized controlled trials have revealed that treatment with infusion of prostacyclin reduces endothelial damage after major surgery...... and AMI. Thus, a study is pertinent to investigate if prostacyclin infusion as a therapeutic intervention reduces endothelial damage without compromising, or even improving, the hemostatic competence in resuscitated cardiac arrest patients. Post-cardiac arrest patients frequently have a need...

  13. Gene transfer strategies for augmenting cardiac function. (United States)

    Peppel, K; Koch, W J; Lefkowitz, R J


    Recent transgenic as well as gene-targeted animal models have greatly increased our understanding of the molecular mechanisms of normal and compromised heart function. These studies have raised the possibility of using somatic gene transfer as a means for improving cardiac function. DNA transfer to a significant portion of the myocardium has thus far been difficult to accomplish. This review describes current efforts to achieve myocardial gene transfer in several model systems, with particular emphasis placed on adenovirus-mediated gene delivery, its possibilities, and current limitations. (Trend Cardiovasc Med 1997;7:145-150). © 1997, Elsevier Science Inc.

  14. Myocardial mitochondrial and contractile function are preserved in mice lacking adiponectin.

    Directory of Open Access Journals (Sweden)

    Martin Braun

    Full Text Available Adiponectin deficiency leads to increased myocardial infarct size following ischemia reperfusion and to exaggerated cardiac hypertrophy following pressure overload, entities that are causally linked to mitochondrial dysfunction. In skeletal muscle, lack of adiponectin results in impaired mitochondrial function. Thus, it was our objective to investigate whether adiponectin deficiency impairs mitochondrial energetics in the heart. At 8 weeks of age, heart weight-to-body weight ratios were not different between adiponectin knockout (ADQ-/- mice and wildtypes (WT. In isolated working hearts, cardiac output, aortic developed pressure and cardiac power were preserved in ADQ-/- mice. Rates of fatty acid oxidation, glucose oxidation and glycolysis were unchanged between groups. While myocardial oxygen consumption was slightly reduced (-24% in ADQ-/- mice in isolated working hearts, rates of maximal ADP-stimulated mitochondrial oxygen consumption and ATP synthesis in saponin-permeabilized cardiac fibers were preserved in ADQ-/- mice with glutamate, pyruvate or palmitoyl-carnitine as a substrate. In addition, enzymatic activity of respiratory complexes I and II was unchanged between groups. Phosphorylation of AMP-activated protein kinase and SIRT1 activity were not decreased, expression and acetylation of PGC-1α were unchanged, and mitochondrial content of OXPHOS subunits was not decreased in ADQ-/- mice. Finally, increasing energy demands due to prolonged subcutaneous infusion of isoproterenol did not differentially affect cardiac contractility or mitochondrial function in ADQ-/- mice compared to WT. Thus, mitochondrial and contractile function are preserved in hearts of mice lacking adiponectin, suggesting that adiponectin may be expendable in the regulation of mitochondrial energetics and contractile function in the heart under non-pathological conditions.

  15. Myocardial mitochondrial and contractile function are preserved in mice lacking adiponectin. (United States)

    Braun, Martin; Hettinger, Niko; Koentges, Christoph; Pfeil, Katharina; Cimolai, Maria C; Hoffmann, Michael M; Osterholt, Moritz; Doenst, Torsten; Bode, Christoph; Bugger, Heiko


    Adiponectin deficiency leads to increased myocardial infarct size following ischemia reperfusion and to exaggerated cardiac hypertrophy following pressure overload, entities that are causally linked to mitochondrial dysfunction. In skeletal muscle, lack of adiponectin results in impaired mitochondrial function. Thus, it was our objective to investigate whether adiponectin deficiency impairs mitochondrial energetics in the heart. At 8 weeks of age, heart weight-to-body weight ratios were not different between adiponectin knockout (ADQ-/-) mice and wildtypes (WT). In isolated working hearts, cardiac output, aortic developed pressure and cardiac power were preserved in ADQ-/- mice. Rates of fatty acid oxidation, glucose oxidation and glycolysis were unchanged between groups. While myocardial oxygen consumption was slightly reduced (-24%) in ADQ-/- mice in isolated working hearts, rates of maximal ADP-stimulated mitochondrial oxygen consumption and ATP synthesis in saponin-permeabilized cardiac fibers were preserved in ADQ-/- mice with glutamate, pyruvate or palmitoyl-carnitine as a substrate. In addition, enzymatic activity of respiratory complexes I and II was unchanged between groups. Phosphorylation of AMP-activated protein kinase and SIRT1 activity were not decreased, expression and acetylation of PGC-1α were unchanged, and mitochondrial content of OXPHOS subunits was not decreased in ADQ-/- mice. Finally, increasing energy demands due to prolonged subcutaneous infusion of isoproterenol did not differentially affect cardiac contractility or mitochondrial function in ADQ-/- mice compared to WT. Thus, mitochondrial and contractile function are preserved in hearts of mice lacking adiponectin, suggesting that adiponectin may be expendable in the regulation of mitochondrial energetics and contractile function in the heart under non-pathological conditions.

  16. Loss of Dendritic Complexity Precedes Neurodegeneration in a Mouse Model with Disrupted Mitochondrial Distribution in Mature Dendrites

    Directory of Open Access Journals (Sweden)

    Guillermo López-Doménech


    Full Text Available Correct mitochondrial distribution is critical for satisfying local energy demands and calcium buffering requirements and supporting key cellular processes. The mitochondrially targeted proteins Miro1 and Miro2 are important components of the mitochondrial transport machinery, but their specific roles in neuronal development, maintenance, and survival remain poorly understood. Using mouse knockout strategies, we demonstrate that Miro1, as opposed to Miro2, is the primary regulator of mitochondrial transport in both axons and dendrites. Miro1 deletion leads to depletion of mitochondria from distal dendrites but not axons, accompanied by a marked reduction in dendritic complexity. Disrupting postnatal mitochondrial distribution in vivo by deleting Miro1 in mature neurons causes a progressive loss of distal dendrites and compromises neuronal survival. Thus, the local availability of mitochondrial mass is critical for generating and sustaining dendritic arbors, and disruption of mitochondrial distribution in mature neurons is associated with neurodegeneration.

  17. Cardiac arrhythmias induced by chloral hydrate in rhesus monkeys. (United States)

    Han, Pengfei; Song, Haibo; Yang, Pingliang; Xie, Huiqi; Kang, Y James


    Chloral hydrate has been long used as a safe sedative and hypnotic drug in humans. However, reports on its cardiovascular adverse effects have been published from time to time. The present study was undertaken to use Rhesus monkeys as a model to define the dose regiment of chloral hydrate at which cardiac arrhythmias can be induced and the consequences of the cardiac events. Male Rhesus monkeys of 2-3 years old were intravenously infused with chloral hydrate starting at 50 mg/kg with an increasing increment of 25 mg/kg until the occurrence of cardiac arrhythmias. In addition, a traditional up-and-down dosing procedure was applied to define a single dose level at which cardiac arrhythmias can be induced. The data obtained showed that when the sequentially escaladed dose reached 125 mg/kg, cardiac arrhythmias occurred in all monkeys tested. The single effective dose to cause cardiac arrhythmias calculated from the crossover analysis was 143 ± 4 mg/kg. This value would be equivalent to 68.6 ± 1.9 mg/kg for children and 46.4 ± 1.3 mg/kg for adults in humans. Under either multiple or single dose condition, cardiac arrhythmias did not occur before 40 min after the onset of anesthesia induced by chloral hydrate. Cardiac arrhythmias were recovered without help at the end of the anesthesia in most cases, but also continued after the regain of consciousness in some cases. The cardiac arrhythmias were accompanied with compromised cardiac function including suppressed fractional shortening and ejection fraction. This study thus suggests that cautions need to be taken when chloral hydrate is used above certain levels and beyond a certain period of anesthesia, and cardiac arrhythmias induced by chloral hydrate need to be closely monitored because compromised cardiac function may occur simultaneously. In addition, patients with cardiac arrhythmias induced by chloral hydrate should be monitored even after they are recovered from the anesthesia.

  18. Mitochondrial phospholipids: role in mitochondrial function. (United States)

    Mejia, Edgard M; Hatch, Grant M


    Mitochondria are essential components of eukaryotic cells and are involved in a diverse set of cellular processes that include ATP production, cellular signalling, apoptosis and cell growth. These organelles are thought to have originated from a symbiotic relationship between prokaryotic cells in an effort to provide a bioenergetic jump and thus, the greater complexity observed in eukaryotes (Lane and Martin 2010). Mitochondrial processes are required not only for the maintenance of cellular homeostasis, but also allow cell to cell and tissue to tissue communication (Nunnari and Suomalainen 2012). Mitochondrial phospholipids are important components of this system. Phospholipids make up the characteristic outer and inner membranes that give mitochondria their shape. In addition, these membranes house sterols, sphingolipids and a wide variety of proteins. It is the phospholipids that also give rise to other characteristic mitochondrial structures such as cristae (formed from the invaginations of the inner mitochondrial membrane), the matrix (area within cristae) and the intermembrane space (IMS) which separates the outer mitochondrial membrane (OMM) and inner mitochondrial membrane (IMM). Phospholipids are the building blocks that make up these structures. However, the phospholipid composition of the OMM and IMM is unique in each membrane. Mitochondria are able to synthesize some of the phospholipids it requires, but the majority of cellular lipid biosynthesis takes place in the endoplasmic reticulum (ER) in conjunction with the Golgi apparatus (Fagone and Jackowski 2009). In this review, we will focus on the role that mitochondrial phospholipids play in specific cellular functions and discuss their biosynthesis, metabolism and transport as well as the differences between the OMM and IMM phospholipid composition. Finally, we will focus on the human diseases that result from disturbances to mitochondrial phospholipids and the current research being performed to help

  19. Mitochondrial helicases and mitochondrial genome maintenance

    DEFF Research Database (Denmark)

    Aamann, Maria Diget; de Souza-Pinto, Nadja C; Kulikowicz, Tomasz;


    Helicases are essential enzymes that utilize the energy of nucleotide hydrolysis to drive unwinding of nucleic acid duplexes. Helicases play roles in all aspects of DNA metabolism including DNA repair, DNA replication and transcription. The subcellular locations and functions of several helicases...... have been studied in detail; however, the roles of specific helicases in mitochondrial biology remain poorly characterized. This review presents important recent advances in identifying and characterizing mitochondrial helicases, some of which also operate in the nucleus....

  20. 22 CFR 213.25 - Standards for compromise. (United States)


    ... proceedings. In evaluating the acceptability of the offer, the CFO may consider, among other factors, the... applicable exemptions available to the debtor under State and Federal law in determining the Government's ability to enforce collection. (b) USAID may compromise a claim, or recommend acceptance of a...

  1. 41 CFR 105-70.046 - Compromise or settlement. (United States)


    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Compromise or settlement. 105-70.046 Section 105-70.046 Public Contracts and Property Management Federal Property Management Regulations System (Continued) GENERAL SERVICES ADMINISTRATION Regional Offices-General...

  2. 14 CFR 1264.145 - Compromise or settlement. (United States)


    ... of compromise or settlement at any time, including proposals for alternative dispute resolution. (b... pendency of any judicial review under § 1264.141 or during the pendency of any civil action to collect... or settle a case under this part during the pendency of any judicial review under 31 U.S.C. 3805...

  3. Evil Searching: Compromise and Recompromise of Internet Hosts for Phishing (United States)

    Moore, Tyler; Clayton, Richard

    Attackers compromise web servers in order to host fraudulent content, such as malware and phishing websites. While the techniques used to compromise websites are widely discussed and categorized, analysis of the methods used by attackers to identify targets has remained anecdotal. In this paper, we study the use of search engines to locate potentially vulnerable hosts. We present empirical evidence from the logs of websites used for phishing to demonstrate attackers’ widespread use of search terms which seek out susceptible web servers. We establish that at least 18% of website compromises are triggered by these searches. Many websites are repeatedly compromised whenever the root cause of the vulnerability is not addressed. We find that 19% of phishing websites are recompromised within six months, and the rate of recompromise is much higher if they have been identified through web search. By contrast, other public sources of information about phishing websites are not currently raising recompromise rates; we find that phishing websites placed onto a public blacklist are recompromised no more frequently than websites only known within closed communities.

  4. Secretion of salivary statherin is compromised in uncontrolled diabetic patients

    Directory of Open Access Journals (Sweden)

    Masahiro Izumi


    Conclusions and general significance: The results show that synthesis and secretion of statherin is reduced in diabetics and this reduction is salivary gland specific. As compromised salivary statherin secretion leads to increased oral health risk, this study indicates that routine oral health assessment of these patients is warranted.

  5. Codeswitching and Compromise Strategies: Implications for Lexical Structure. (United States)

    Jake, Janice L.; Myers-Scotton, Carol


    Deals with two compromise strategies: (1) embedded language islands (EL Islands), and (2) "bare forms" in code switching (CS) within the projection of complementizer. These elements are discussed within the framework of the Matrix Language Frame Model. Shows how this model provides an explanatory account for the occurrence of both EL…

  6. Tissue response: biomaterials, dental implants, and compromised osseous tissue. (United States)

    Babu RS, Arvind; Ogle, Orrett


    Tissue response represents an important feature in biocompatibility in implant procedures. This review article highlights the fundamental characteristics of tissue response after the implant procedure. This article also highlights the tissue response in compromised osseous conditions. Understanding the histologic events after dental implants in normal and abnormal bone reinforces the concept of case selection in dental implants.

  7. Time-to-Compromise Model for Cyber Risk Reduction Estimation

    Energy Technology Data Exchange (ETDEWEB)

    Miles A. McQueen; Wayne F. Boyer; Mark A. Flynn; George A. Beitel


    We propose a new model for estimating the time to compromise a system component that is visible to an attacker. The model provides an estimate of the expected value of the time-to-compromise as a function of known and visible vulnerabilities, and attacker skill level. The time-to-compromise random process model is a composite of three subprocesses associated with attacker actions aimed at the exploitation of vulnerabilities. In a case study, the model was used to aid in a risk reduction estimate between a baseline Supervisory Control and Data Acquisition (SCADA) system and the baseline system enhanced through a specific set of control system security remedial actions. For our case study, the total number of system vulnerabilities was reduced by 86% but the dominant attack path was through a component where the number of vulnerabilities was reduced by only 42% and the time-to-compromise of that component was increased by only 13% to 30% depending on attacker skill level.

  8. Cardiac tamponade (image) (United States)

    Cardiac tamponade is a condition involving compression of the heart caused by blood or fluid accumulation in the space ... they cannot adequately fill or pump blood. Cardiac tamponade is an emergency condition that requires hospitalization.

  9. What Is Cardiac Rehabilitation? (United States)

    ANSWERS by heart Treatments + Tests What Is Cardiac Rehabilitation? A cardiac rehabilitation (rehab) program takes place in a hospital or ... special help in making lifestyle changes. During your rehabilitation program you’ll… • Have a medical evaluation to ...

  10. Protein kinase B (PKB/AKT1) formed signaling complexes with mitochondrial proteins and prevented glycolytic energy dysfunction in cultured cardiomyocytes during ischemia-reperfusion injury. (United States)

    Deng, Wu; Leu, Hsin-Bang; Chen, Yumay; Chen, Yu-Han; Epperson, Christine M; Juang, Charity; Wang, Ping H


    Our previous studies showed that insulin stimulated AKT1 translocation into mitochondria and modulated oxidative phosphorylation complex V in cardiac muscle. This raised the possibility that mitochondrial AKT1 may regulate glycolytic oxidative phosphorylation and mitochondrial function in cardiac muscle cells. The aims of this project were to study the effects of mitochondrial AKT1 signaling on cell survival in stressed cardiomyocytes, to define the effect of mitochondrial AKT1 signaling on glycolytic bioenergetics, and to identify mitochondrial targets of AKT1 signaling in cardiomyocytes. Mitochondrial AKT1 signaling played a protective role against apoptosis and necrosis during ischemia-reperfusion stress, suppressed mitochondrial calcium overload, and alleviated mitochondrial membrane depolarization. Activation of AKT1 signaling in mitochondria increased glucose uptake, enhanced respiration efficiency, reduced superoxide generation, and increased ATP production in the cardiomyocytes. Inhibition of mitochondrial AKT attenuated insulin response, indicating that insulin regulation of ATP production required mitochondrial AKT1 signaling. A proteomic approach was used to reveal 15 novel targets of AKT1 signaling in mitochondria, including pyruvate dehydrogenase complex (PDC). We have confirmed and characterized the association of AKT1 and PDC subunits and verified a stimulatory effect of mitochondrial AKT1 on the enzymatic activity of PDC. These findings suggested that AKT1 formed protein complexes with multiple mitochondrial proteins and improved mitochondrial function in stressed cardiomyocytes. The novel AKT1 signaling targets in mitochondria may become a resource for future metabolism research.

  11. Cardiac sodium channelopathies

    NARCIS (Netherlands)

    Amin, A.S.; Asghari-Roodsari, A.; Tan, H.L.


    Cardiac sodium channel are protein complexes that are expressed in the sarcolemma of cardiomyocytes to carry a large inward depolarizing current (I-Na) during phase 0 of the cardiac action potential. The importance of I-Na for normal cardiac electrical activity is reflected by the high incidence of

  12. Mitochondrial Biogenesis and Turnover


    Diaz, Francisca; Moraes, Carlos T.


    Mitochondrial biogenesis is a complex process involving the coordinated expression of mitochondrial and nuclear genes, the import of the products of the latter into the organelle and turnover. The mechanisms associated with these events have been intensively studied in the last twenty years and our understanding of their details is much improved. Mitochondrial biogenesis requires the participation of calcium signaling that activates a series of calcium dependent protein kinases that in turn a...

  13. [Mitochondrial and oocyte development]. (United States)

    Deng, Wei-Ping; Ren, Zhao-Rui


    Oocyte development and maturation is a complicated process. The nuclear maturation and cytoplasmic maturation must synchronize which can ensure normal oocyte fertilization and following development. Mitochondrial is the most important cellular organell in cytoplasm, and the variation of its distribution during oocyte maturation, the capacity of OXPHOS generating ATP as well as the content or copy number or transcription level of mitochondrial DNA play an important role in oocyte development and maturation. Therefore, the studies on the variation of mitochondrial distribution, function and mitochondrial DNA could enhance our understanding of the physiology of reproduction and provide new insight to solve the difficulties of assisted reproduction as well as cloning embryo technology.

  14. Progress in mitochondrial epigenetics. (United States)

    Manev, Hari; Dzitoyeva, Svetlana


    Mitochondria, intracellular organelles with their own genome, have been shown capable of interacting with epigenetic mechanisms in at least four different ways. First, epigenetic mechanisms that regulate the expression of nuclear genome influence mitochondria by modulating the expression of nuclear-encoded mitochondrial genes. Second, a cell-specific mitochondrial DNA content (copy number) and mitochondrial activity determine the methylation pattern of nuclear genes. Third, mitochondrial DNA variants influence the nuclear gene expression patterns and the nuclear DNA (ncDNA) methylation levels. Fourth and most recent line of evidence indicates that mitochondrial DNA similar to ncDNA also is subject to epigenetic modifications, particularly by the 5-methylcytosine and 5-hydroxymethylcytosine marks. The latter interaction of mitochondria with epigenetics has been termed 'mitochondrial epigenetics'. Here we summarize recent developments in this particular area of epigenetic research. Furthermore, we propose the term 'mitoepigenetics' to include all four above-noted types of interactions between mitochondria and epigenetics, and we suggest a more restricted usage of the term 'mitochondrial epigenetics' for molecular events dealing solely with the intra-mitochondrial epigenetics and the modifications of mitochondrial genome.

  15. Mitochondrial DNA Mutation Associated with Leber's Hereditary Optic Neuropathy (United States)

    Wallace, Douglas C.; Singh, Gurparkash; Lott, Marie T.; Hodge, Judy A.; Schurr, Theodore G.; Lezza, Angela M. S.; Elsas, Louis J.; Nikoskelainen, Eeva K.


    Leber's hereditary optic neuropathy is a maternally inherited disease resulting in optic nerve degeneration and cardiac dysrhythmia. A mitochondrial DNA replacement mutation was identified that correlated with this disease in multiple families. This mutation converted a highly conserved arginine to a histidine at codon 340 in the NADH dehydrogenase subunit 4 gene and eliminated an Sfa NI site, thus providing a simple diagnostic test. This finding demonstrated that a nucleotide change in a mitochondrial DNA energy production gene can result in a neurological disease.

  16. Do mitochondria limit hot fish hearts? Understanding the role of mitochondrial function with heat stress in Notolabrus celidotus. (United States)

    Iftikar, Fathima I; Hickey, Anthony J R


    Hearts are the first organs to fail in animals exposed to heat stress. Predictions of climate change mediated increases in ocean temperatures suggest that the ectothermic heart may place tight constraints on the diversity and distribution of marine species with cardiovascular systems. For many such species, their upper temperature limits (Tmax) and respective heart failure (HF) temperature (T(HF)) are only a few degrees from current environmental temperatures. While the ectothermic cardiovascular system acts as an "ecological thermometer," the exact mechanism that mediates HF remains unresolved. We propose that heat-stressed cardiac mitochondria drive HF. Using a common New Zealand fish, Notolabrus celidotus, we determined the THF (27.5°C). Haemoglobin oxygen saturation appeared to be unaltered in the blood surrounding and within heat stressed hearts. Using high resolution respirometry coupled to fluorimeters, we explored temperature-mediated changes in respiration, ROS and ATP production, and overlaid these changes with T(HF). Even at saturating oxygen levels several mitochondrial components were compromised before T(HF). Importantly, the capacity to efficiently produce ATP in the heart is limited at 25°C, and this is prior to the acute T(HF) for N. celidotus. Membrane leakiness increased significantly at 25°C, as did cytochrome c release and permeability to NADH. Maximal flux rates and the capacity for the electron transport system to uncouple were also altered at 25°C. These data indicate that mitochondrial membrane integrity is lost, depressing ATP synthesis capacity and promoting cytochrome c release, prior to T(HF). Mitochondria can mediate HF in heat stressed hearts in fish and play a significant role in thermal stress tolerance, and perhaps limit species distributions by contributing to HF.

  17. Mechanisms of cardiac pain. (United States)

    Foreman, Robert D; Garrett, Kennon M; Blair, Robert W


    Angina pectoris is cardiac pain that typically is manifested as referred pain to the chest and upper left arm. Atypical pain to describe localization of the perception, generally experienced more by women, is referred to the back, neck, and/or jaw. This article summarizes the neurophysiological and pharmacological mechanisms for referred cardiac pain. Spinal cardiac afferent fibers mediate typical anginal pain via pathways from the spinal cord to the thalamus and ultimately cerebral cortex. Spinal neurotransmission involves substance P, glutamate, and transient receptor potential vanilloid-1 (TRPV1) receptors; release of neurokinins such as nuclear factor kappa b (NF-kb) in the spinal cord can modulate neurotransmission. Vagal cardiac afferent fibers likely mediate atypical anginal pain and contribute to cardiac ischemia without accompanying pain via relays through the nucleus of the solitary tract and the C1-C2 spinal segments. The psychological state of an individual can modulate cardiac nociception via pathways involving the amygdala. Descending pathways originating from nucleus raphe magnus and the pons also can modulate cardiac nociception. Sensory input from other visceral organs can mimic cardiac pain due to convergence of this input with cardiac input onto spinothalamic tract neurons. Reduction of converging nociceptive input from the gallbladder and gastrointestinal tract can diminish cardiac pain. Much work remains to be performed to discern the interactions among complex neural pathways that ultimately produce or do not produce the sensations associated with cardiac pain.

  18. p53 regulates the cardiac transcriptome (United States)

    Mak, Tak W.; Hauck, Ludger; Grothe, Daniela; Billia, Filio


    The tumor suppressor Trp53 (p53) inhibits cell growth after acute stress by regulating gene transcription. The mammalian genome contains hundreds of p53-binding sites. However, whether p53 participates in the regulation of cardiac tissue homeostasis under normal conditions is not known. To examine the physiologic role of p53 in adult cardiomyocytes in vivo, Cre-loxP–mediated conditional gene targeting in adult mice was used. Genome-wide transcriptome analyses of conditional heart-specific p53 knockout mice were performed. Genome-wide annotation and pathway analyses of >5,000 differentially expressed transcripts identified many p53-regulated gene clusters. Correlative analyses identified >20 gene sets containing more than 1,000 genes relevant to cardiac architecture and function. These transcriptomic changes orchestrate cardiac architecture, excitation-contraction coupling, mitochondrial biogenesis, and oxidative phosphorylation capacity. Interestingly, the gene expression signature in p53-deficient hearts confers resistance to acute biomechanical stress. The data presented here demonstrate a role for p53, a previously unrecognized master regulator of the cardiac transcriptome. The complex contributions of p53 define a biological paradigm for the p53 regulator network in the heart under physiological conditions. PMID:28193895

  19. Pim-1 preserves mitochondrial morphology by inhibiting dynamin-related protein 1 translocation. (United States)

    Din, Shabana; Mason, Matthew; Völkers, Mirko; Johnson, Bevan; Cottage, Christopher T; Wang, Zeping; Joyo, Anya Y; Quijada, Pearl; Erhardt, Peter; Magnuson, Nancy S; Konstandin, Mathias H; Sussman, Mark A


    Mitochondrial morphological dynamics affect the outcome of ischemic heart damage and pathogenesis. Recently, mitochondrial fission protein dynamin-related protein 1 (Drp1) has been identified as a mediator of mitochondrial morphological changes and cell death during cardiac ischemic injury. In this study, we report a unique relationship between Pim-1 activity and Drp1 regulation of mitochondrial morphology in cardiomyocytes challenged by ischemic stress. Transgenic hearts overexpressing cardiac Pim-1 display reduction of total Drp1 protein levels, increased phosphorylation of Drp1-(S637), and inhibition of Drp1 localization to the mitochondria. Consistent with these findings, adenoviral-induced Pim-1 neonatal rat cardiomyocytes (NRCMs) retain a reticular mitochondrial phenotype after simulated ischemia (sI) and decreased Drp1 mitochondrial sequestration. Interestingly, adenovirus Pim-dominant negative NRCMs show increased expression of Bcl-2 homology 3 (BH3)-only protein p53 up-regulated modulator of apoptosis (PUMA), which has been previously shown to induce Drp1 accumulation at mitochondria and increase sensitivity to apoptotic stimuli. Overexpression of the p53 up-regulated modulator of apoptosis-dominant negative adenovirus attenuates localization of Drp1 to mitochondria in adenovirus Pim-dominant negative NRCMs promotes reticular mitochondrial morphology and inhibits cell death during sI. Therefore, Pim-1 activity prevents Drp1 compartmentalization to the mitochondria and preserves reticular mitochondrial morphology in response to sI.

  20. Securing Single Points of Compromise (SPoC)

    Energy Technology Data Exchange (ETDEWEB)

    Belangia, David Warren [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    Securing the Single Points of Compromise that provide central services to the institution’s environment is paramount to success when trying to protect the business. (Fisk, 2014) Time Based Security mandates protection (erecting and ensuring effective controls) that last longer than the time to detect and react to a compromise. When enterprise protections fail, providing additional layered controls for these central services provides more time to detect and react. While guidance is readily available for securing the individual critical asset, protecting these assets as a group is not often discussed. Using best business practices to protect these resources as individual assets while leveraging holistic defenses for the group increases the opportunity to maximize protection time, allowing detection and reaction time for the SPoCs that is commensurate with the inherent risk of these centralized services.

  1. Creating clones, kids & chimera: liberal democratic compromise at the crossroads. (United States)

    Adams, Nathan A


    The objective of this article is to find middle ground between the supporters and opponents of biotechnology by perpetuating the existing legal compromise pertaining to the complete range of health and welfare doctrines relevant to the biotechnological industry. The author aspires neither to add to nor detract from this liberal democratic consensus, but to preserve its constitutive balance between positivism and natural law and over-regulation and under-regulation in the hopes of stabilizing new political fault lines developing around the few biotechnological innovations already grabbing headlines. The most feasible solution is to extend the existing liberal democratic compromise with respect to equal protection, reproductive rights, the First Amendment, human subject experimentation, patent law, and parental rights. This includes banning or monopolizing certain biotechnologies and extending substantive special respect to the ex vivo living human embryo. Biotechnology must not be left to regulate itself.

  2. Roles of Melatonin in Fetal Programming in Compromised Pregnancies

    Directory of Open Access Journals (Sweden)

    Yu-Chieh Chen


    Full Text Available Compromised pregnancies such as those associated with gestational diabetes mellitus, intrauterine growth retardation, preeclampsia, maternal undernutrition, and maternal stress may negatively affect fetal development. Such pregnancies may induce oxidative stress to the fetus and alter fetal development through the epigenetic process that may affect development at a later stage. Melatonin is an oxidant scavenger that reverses oxidative stress during the prenatal period. Moreover, the role of melatonin in epigenetic modifications in the field of developmental programming has been studied extensively. Here, we describe the physiological function of melatonin in pregnancy and discuss the roles of melatonin in fetal programming in compromised pregnancies, focusing on its involvement in redox and epigenetic mechanisms.

  3. Addressing diversity in schools through dialogue and compromise

    DEFF Research Database (Denmark)

    Olsen, Tore Vincents


    This article evaluates a decentralized Danish model for dealing with cultural and religious diversity at individual schools. This evaluation is based upon normative theories of toleration, recognition and domination and examines whether the model implies compromise with the (liberal) educational...... values stipulated in the national legislation. The model, reconstructed from government publications, is based on reaching accommodation through dialogue between school staff and parents/students, with the pragmatic aim of facilitating the participation of students in everyday school activities...

  4. Sophia's Compromises and Fielding's Creation of a Patriarchal World

    Institute of Scientific and Technical Information of China (English)



    Traditionally, critics maintain that Henry Fielding has created an ideal heroine, Sophia, in his novel The History of Tom Jones.This paper argues that Sophia is not a very successful woman character since she fails to be an autonomous individual and has to make compromises with the patriarchal world created by Fielding.Relating to this, Fielding's male Chauvinism embodied in this novel will also be explored by analyzing other women characters.

  5. The ethics of moral compromise for stem cell research policy. (United States)

    Master, Zubin; Crozier, G K D


    In the US, stem cell research is at a moral impasse-many see this research as ethically mandated due to its potential for ameliorating major diseases, while others see this research as ethically impermissible because it typically involves the destruction of embryos and use of ova from women. Because their creation does not require embryos or ova, induced pluripotent stem cells offer the most promising path for addressing the main ethical objections to stem cell research; however, this technology is still in development. In order for scientists to advance induced pluripotent stem cell research to a point of translational readiness, they must continue to use ova and embryos in the interim. How then are we to ethically move forward with stem cell research? We argue that there is personal integrity and value in adopting a 'moral compromise' as a means for moving past the moral impasse in stem cell research. In a moral compromise, each party concedes part of their desired outcome in order to engage in a process that respects the values and desires of all parties equitably. Whereas some contend that moral compromise in stem cell research necessarily involves self-contradiction or loss of personal integrity, we argue that in the US context, stem cell research satisfies many of the key pre-conditions of an effective moral compromise. To illustrate our point, we offer a model solution wherein eggs and embryos are temporarily used until non-egg and non-embryonic sources of pluripotent stem cells are developed to a state of translational readiness.

  6. Mitochondrial Energy-Deficient Endophenotype in Autism

    Directory of Open Access Journals (Sweden)

    J. J. Gargus


    Full Text Available While evidence points to a multigenic etiology of most autism, the pathophysiology of the disorder has yet to be defined and the underlying genes and biochemical pathways they subserve remain unknown. Autism is considered to be influenced by a combination of various genetic, environmental and immunological factors; more recently, evidence has suggested that increased vulnerability to oxidative stress may be involved in the etiology of this multifactorial disorder. Furthermore, recent studies have pointed to a subset of autism associated with the biochemical endophenotype of mitochondrial energy deficiency, identified as a subtle impairment in fat and carbohydrate oxidation. This phenotype is similar, but more subtle than those seen in classic mitochondrial defects. In some cases the beginnings of the genetic underpinnings of these mitochondrial defects are emerging, such as mild mitochondrial dysfunction and secondary carnitine deficiency observed in the subset of autistic patients with an inverted duplication of chromosome 15q11-q13. In addition, rare cases of familial autism associated with sudden infant death syndrome (SIDS or associated with abnormalities in cellular calcium homeostasis, such as malignant hyperthermia or cardiac arrhythmia, are beginning to emerge. Such special cases suggest that the pathophysiology of autism may comprise pathways that are directly or indirectly involved in mitochondrial energy production and to further probe this connection three new avenues seem worthy of exploration: 1 metabolomic clinical studies provoking controlled aerobic exercise stress to expand the biochemical phenotype, 2 high-throughput expression arrays to directly survey activity of the genes underlying these biochemical pathways and 3 model systems, either based upon neuronal stem cells or model genetic organisms, to discover novel genetic and environmental inputs into these pathways.

  7. Live imaging of mitochondrial dynamics in CNS dopaminergic neurons in vivo demonstrates early reversal of mitochondrial transport following MPP(+) exposure. (United States)

    Dukes, April A; Bai, Qing; Van Laar, Victor S; Zhou, Yangzhong; Ilin, Vladimir; David, Christopher N; Agim, Zeynep S; Bonkowsky, Joshua L; Cannon, Jason R; Watkins, Simon C; Croix, Claudette M St; Burton, Edward A; Berman, Sarah B


    Extensive convergent evidence collectively suggests that mitochondrial dysfunction is central to the pathogenesis of Parkinson's disease (PD). Recently, changes in the dynamic properties of mitochondria have been increasingly implicated as a key proximate mechanism underlying neurodegeneration. However, studies have been limited by the lack of a model in which mitochondria can be imaged directly and dynamically in dopaminergic neurons of the intact vertebrate CNS. We generated transgenic zebrafish in which mitochondria of dopaminergic neurons are labeled with a fluorescent reporter, and optimized methods allowing direct intravital imaging of CNS dopaminergic axons and measurement of mitochondrial transport in vivo. The proportion of mitochondria undergoing axonal transport in dopaminergic neurons decreased overall during development between 2days post-fertilization (dpf) and 5dpf, at which point the major period of growth and synaptogenesis of the relevant axonal projections is complete. Exposure to 0.5-1.0mM MPP(+) between 4 and 5dpf did not compromise zebrafish viability or cause detectable changes in the number or morphology of dopaminergic neurons, motor function or monoaminergic neurochemistry. However, 0.5mM MPP(+) caused a 300% increase in retrograde mitochondrial transport and a 30% decrease in anterograde transport. In contrast, exposure to higher concentrations of MPP(+) caused an overall reduction in mitochondrial transport. This is the first time mitochondrial transport has been observed directly in CNS dopaminergic neurons of a living vertebrate and quantified in a PD model in vivo. Our findings are compatible with a model in which damage at presynaptic dopaminergic terminals causes an early compensatory increase in retrograde transport of compromised mitochondria for degradation in the cell body. These data are important because manipulation of early pathogenic mechanisms might be a valid therapeutic approach to PD. The novel transgenic lines and

  8. Defects of mitochondrial DNA replication. (United States)

    Copeland, William C


    Mitochondrial DNA is replicated by DNA polymerase γ in concert with accessory proteins such as the mitochondrial DNA helicase, single-stranded DNA binding protein, topoisomerase, and initiating factors. Defects in mitochondrial DNA replication or nucleotide metabolism can cause mitochondrial genetic diseases due to mitochondrial DNA deletions, point mutations, or depletion, which ultimately cause loss of oxidative phosphorylation. These genetic diseases include mitochondrial DNA depletion syndromes such as Alpers or early infantile hepatocerebral syndromes, and mitochondrial DNA deletion disorders, such as progressive external ophthalmoplegia, ataxia-neuropathy, or mitochondrial neurogastrointestinal encephalomyopathy. This review focuses on our current knowledge of genetic defects of mitochondrial DNA replication (POLG, POLG2, C10orf2, and MGME1) that cause instability of mitochondrial DNA and mitochondrial disease.

  9. Adaptive changes in renal mitochondrial redox status in diabetic nephropathy

    Energy Technology Data Exchange (ETDEWEB)

    Putt, David A.; Zhong, Qing; Lash, Lawrence H., E-mail:


    Nephropathy is a serious and common complication of diabetes. In the streptozotocin (STZ)-treated rat model of diabetes, nephropathy does not typically develop until 30 to 45 days post-injection, although hyperglycemia occurs within 24 h. We tested the hypothesis that chronic hyperglycemia results in a modest degree of oxidative stress that is accompanied by compensatory changes in certain antioxidants and mitochondrial redox status. We propose that as kidneys progress to a state of diabetic nephropathy, further adaptations occur in mitochondrial redox status. Basic parameters of renal function in vivo and several parameters of mitochondrial function and glutathione (GSH) and redox status in isolated renal cortical mitochondria from STZ-treated and age-matched control rats were examined at 30 days and 90 days post-injection. While there was no effect of diabetes on blood urea nitrogen, measurement of other, more sensitive parameters, such as urinary albumin and protein, and histopathology showed significant and progressive worsening in diabetic rats. Thus, renal function is compromised even prior to the onset of frank nephropathy. Changes in mitochondrial respiration and enzyme activities indicated existence of a hypermetabolic state. Higher mitochondrial GSH content and rates of GSH transport into mitochondria in kidneys from diabetic rats were only partially due to changes in expression of mitochondrial GSH carriers and were mostly due to higher substrate supply. Although there are few clear indicators of oxidative stress, there are several redox changes that occur early and change further as nephropathy progresses, highlighting the complexity of the disease. Highlights: ►Adaptive changes in renal mitochondrial and redox status in diabetic rats. ►Modest renal dysfunction even prior to onset of nephropathy. ►Elevated concentrations of mitochondrial GSH in diabetic kidneys. ►Change in GSH due partly to increased protein expression of transporter.

  10. Stimulating endogenous cardiac regeneration

    Directory of Open Access Journals (Sweden)

    Amanda eFinan


    Full Text Available The healthy adult heart has a low turnover of cardiac myocytes. The renewal capacity, however, is augmented after cardiac injury. Participants in cardiac regeneration include cardiac myocytes themselves, cardiac progenitor cells, and peripheral stem cells, particularly from the bone marrow compartment. Cardiac progenitor cells and bone marrow stem cells are augmented after cardiac injury, migrate to the myocardium, and support regeneration. Depletion studies of these populations have demonstrated their necessary role in cardiac repair. However, the potential of these cells to completely regenerate the heart is limited. Efforts are now being focused on ways to augment these natural pathways to improve cardiac healing, primarily after ischemic injury but in other cardiac pathologies as well. Cell and gene therapy or pharmacological interventions are proposed mechanisms. Cell therapy has demonstrated modest results and has passed into clinical trials. However, the beneficial effects of cell therapy have primarily been their ability to produce paracrine effects on the cardiac tissue and recruit endogenous stem cell populations as opposed to direct cardiac regeneration. Gene therapy efforts have focused on prolonging or reactivating natural signaling pathways. Positive results have been demonstrated to activate the endogenous stem cell populations and are currently being tested in clinical trials. A potential new avenue may be to refine pharmacological treatments that are currently in place in the clinic. Evidence is mounting that drugs such as statins or beta blockers may alter endogenous stem cell activity. Understanding the effects of these drugs on stem cell repair while keeping in mind their primary function may strike a balance in myocardial healing. To maximize endogenous cardiac regeneration,a combination of these approaches couldameliorate the overall repair process to incorporate the participation ofmultiple cell players.

  11. Cardioprotection by modulation of mitochondrial respiration during ischemia–reperfusion: Role of apoptosis-inducing factor

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Aijun [Department of Internal Medicine (Division of Cardiology), Virginia Commonwealth University, Richmond, VA 23298 (United States); Department of Anesthesiology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030 (China); Szczepanek, Karol; Hu, Ying [Department of Internal Medicine (Division of Cardiology), Virginia Commonwealth University, Richmond, VA 23298 (United States); Lesnefsky, Edward J. [Department of Internal Medicine (Division of Cardiology), Virginia Commonwealth University, Richmond, VA 23298 (United States); Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA 23298 (United States); Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, VA 23298 (United States); McGuire Department of Veterans Affairs Medical Center, Richmond, VA 23249 (United States); Chen, Qun, E-mail: [Department of Internal Medicine (Division of Cardiology), Virginia Commonwealth University, Richmond, VA 23298 (United States)


    Highlights: •Blockade of electron transport prevents the loss of AIF from mitochondria during IR. •Blockade of electron transport decreases caspase-independent cell death during IR. •Mitochondrial AIF content is down-regulated in Harlequin mice. •Blockade of electron transport protects Harlequin mouse hearts during IR. •Amobarbital protection is partially dependent on mitochondrial AIF content. -- Abstract: The transient, reversible blockade of electron transport (BET) during ischemia or at the onset of reperfusion protects mitochondria and decreases cardiac injury. Apoptosis inducing factor (AIF) is located within the mitochondrial intermembrane space. A release of AIF from mitochondria into cytosol and nucleus triggers caspase-independent cell death. We asked if BET prevents the loss of AIF from mitochondria as a mechanism of protection in the buffer perfused heart. BET during ischemia with amobarbital, a rapidly reversible inhibitor of mitochondrial complex I, attenuated a release of AIF from mitochondria into cytosol, in turn decreasing the formation of cleaved and activated PARP-1. These results suggest that BET-mediated protection may occur through prevention of the loss of AIF from mitochondria during ischemia–reperfusion. In order to further clarify the role of mitochondrial AIF in BET-mediated protection, Harlequin (Hq) mice, a genetic model with mitochondrial AIF deficiency, were used to test whether BET could still decrease cell injury in Hq mouse hearts during reperfusion. BET during ischemia protected Hq mouse hearts against ischemia–reperfusion injury and improved mitochondrial function in these hearts during reperfusion. Thus, cardiac injury can still be decreased in the presence of down-regulated mitochondrial AIF content. Taken together, BET during ischemia protects both hearts with normal mitochondrial AIF content and hearts with mitochondrial AIF deficiency. Although preservation of mitochondrial AIF content plays a key role in

  12. Full-length PGC-1α salvages the phenotype of a mouse model of human neuropathy through mitochondrial proliferation. (United States)

    Rona-Voros, Krisztina; Eschbach, Judith; Vernay, Aurélia; Wiesner, Diana; Schwalenstocker, Birgit; Geniquet, Pauline; Mousson De Camaret, Bénédicte; Echaniz-Laguna, Andoni; Loeffler, Jean-Philippe; Ludolph, Albert C; Weydt, Patrick; Dupuis, Luc


    Increased mitochondrial mass, commonly termed mitochondrial proliferation, is frequently observed in many human diseases directly or indirectly involving mitochondrial dysfunction. Mitochondrial proliferation is thought to counterbalance a compromised energy metabolism, yet it might also be detrimental through alterations of mitochondrial regulatory functions such as apoptosis, calcium metabolism or oxidative stress. Here, we show that prominent mitochondrial proliferation occurs in Cramping mice, a model of hereditary neuropathy caused by a mutation in the dynein heavy chain gene Dync1h1. The mitochondrial proliferation correlates with post-prandial induction of full-length (FL) and N-terminal truncated (NT) isoforms of the transcriptional co-activator PGC-1α. The selective knock-out of FL-PGC-1α isoform, preserving expression and function of NT-PGC-1α, led to a complete reversal of mitochondrial proliferation. Moreover, FL-PGC-1α ablation potently exacerbated the mitochondrial dysfunction and led to severe weight loss. Finally, FL-PGC-1α ablation triggered pronounced locomotor dysfunction, tremors and inability to rear in Cramping mice. In summary, endogenous FL-PGC-1α activates mitochondrial proliferation and salvages neurological and metabolic health upon disease. NT-PGC-1α cannot fulfil this protective action. Activation of this endogenous salvage pathway might thus be a valuable therapeutic target for diseases involving mitochondrial dysfunction.

  13. UCP3 Regulates Single-Channel Activity of the Cardiac mCa1. (United States)

    Motloch, Lukas J; Gebing, Tina; Reda, Sara; Schwaiger, Astrid; Wolny, Martin; Hoppe, Uta C


    Mitochondrial Ca(2+) uptake (mCa(2+) uptake) is thought to be mediated by the mitochondrial Ca(2+) uniporter (MCU). UCP2 and UCP3 belong to a superfamily of mitochondrial ion transporters. Both proteins are expressed in the inner mitochondrial membrane of the heart. Recently, UCP2 was reported to modulate the function of the cardiac MCU related channel mCa1. However, the possible role of UCP3 in modulating cardiac mCa(2+) uptake via the MCU remains inconclusive. To understand the role of UCP3, we analyzed cardiac mCa1 single-channel activity in mitoplast-attached single-channel recordings from isolated murine cardiac mitoplasts, from adult wild-type controls (WT), and from UCP3 knockout mice (UCP3(-/-)). Single-channel registrations in UCP3(-/-) confirmed a murine voltage-gated Ca(2+) channel, i.e., mCa1, which was inhibited by Ru360. Compared to WT, mCa1 in UCP3(-/-) revealed similar single-channel characteristics. However, in UCP3(-/-) the channel exhibited decreased single-channel activity, which was insensitive to adenosine triphosphate (ATP) inhibition. Our results suggest that beyond UCP2, UCP3 also exhibits regulatory effects on cardiac mCa1/MCU function. Furthermore, we speculate that UCP3 might modulate previously described inhibitory effects of ATP on mCa1/MCU activity as well.

  14. Marketing cardiac CT programs. (United States)

    Scott, Jason


    There are two components of cardiac CT discussed in this article: coronary artery calcium scoring (CACS) and coronary computed tomography angiography (CCTA).The distinctive advantages of each CT examination are outlined. In order to ensure a successful cardiac CT program, it is imperative that imaging facilities market their cardiac CT practices effectively in order to gain a competitive advantage in this valuable market share. If patients receive quality care by competent individuals, they are more likely to recommend the facility's cardiac CT program. Satisfied patients will also be more willing to come back for any further testing.

  15. Private mitochondrial DNA variants in danish patients with hypertrophic cardiomyopathy

    DEFF Research Database (Denmark)

    Hagen, Christian M; Aidt, Frederik H; Havndrup, Ole;


    Hypertrophic cardiomyopathy (HCM) is a genetic cardiac disease primarily caused by mutations in genes coding for sarcomeric proteins. A molecular-genetic etiology can be established in ~60% of cases. Evolutionarily conserved mitochondrial DNA (mtDNA) haplogroups are susceptibility factors for HCM....... Several polymorphic mtDNA variants are associated with a variety of late-onset degenerative diseases and affect mitochondrial function. We examined the role of private, non-haplogroup associated, mitochondrial variants in the etiology of HCM. In 87 Danish HCM patients, full mtDNA sequencing revealed 446......>G, and MT-CYB: m.15024G>A, p.C93Y remained. A detailed analysis of these variants indicated that none of them are likely to cause HCM. In conclusion, private mtDNA mutations are frequent, but they are rarely, if ever, associated with HCM....

  16. The mitochondrial uniporter controls fight or flight heart rate increases. (United States)

    Wu, Yuejin; Rasmussen, Tyler P; Koval, Olha M; Joiner, Mei-Ling A; Hall, Duane D; Chen, Biyi; Luczak, Elizabeth D; Wang, Qiongling; Rokita, Adam G; Wehrens, Xander H T; Song, Long-Sheng; Anderson, Mark E


    Heart rate increases are a fundamental adaptation to physiological stress, while inappropriate heart rate increases are resistant to current therapies. However, the metabolic mechanisms driving heart rate acceleration in cardiac pacemaker cells remain incompletely understood. The mitochondrial calcium uniporter (MCU) facilitates calcium entry into the mitochondrial matrix to stimulate metabolism. We developed mice with myocardial MCU inhibition by transgenic expression of a dominant-negative (DN) MCU. Here, we show that DN-MCU mice had normal resting heart rates but were incapable of physiological fight or flight heart rate acceleration. We found that MCU function was essential for rapidly increasing mitochondrial calcium in pacemaker cells and that MCU-enhanced oxidative phoshorylation was required to accelerate reloading of an intracellular calcium compartment before each heartbeat. Our findings show that MCU is necessary for complete physiological heart rate acceleration and suggest that MCU inhibition could reduce inappropriate heart rate increases without affecting resting heart rate.

  17. A role for Sp and nuclear receptor transcription factors in a cardiac hypertrophic growth program


    Sack, Michael N.; Disch, Dennis L.; Rockman, Howard A.; Kelly, Daniel P


    During cardiac hypertrophy, the chief myocardial energy source switches from fatty acid β-oxidation (FAO) to glycolysis—a reversion to fetal metabolism. The expression of genes encoding myocardial FAO enzymes was delineated in a murine ventricular pressure overload preparation to characterize the molecular regulatory events involved in the alteration of energy substrate utilization during cardiac hypertrophy. Expression of genes involved in the thioesterification, mitochondrial import, and β-...

  18. Role of mitochondrial lipids in guiding fission and fusion. (United States)

    Frohman, Michael A


    Clinically important links have been established between mitochondrial function and cardiac physiology and disease in the context of signaling mechanisms, energy production, and muscle cell development. The proteins and processes that drive mitochondrial fusion and fission are now known to have emergent functions in intracellular calcium homeostasis, apoptosis, vascular smooth muscle cell proliferation, myofibril organization, and Notch-driven cell differentiation, all key issues in cardiac disease. Moreover, decreasing fission may confer protection against ischemic heart disease, particularly in the setting of obesity, diabetes, and heart failure. The importance of lipids in controlling mitochondrial fission and fusion is increasingly becoming appreciated. Roles for the bulk and signaling lipids cardiolipin, phosphatidylethanolamine, phosphatidic acid, diacylglycerol, and lysophosphatidic acid and the enzymes that synthesize or metabolize them in the control of mitochondrial shape and function are reviewed here. A number of diseases have been linked to loss-of-function alleles for a subset of the enzymes, emphasizing the importance of the lipid environment in this context.

  19. The Swiss approach to finding compromises in nuclear waste governance

    Energy Technology Data Exchange (ETDEWEB)

    Kuppler, Sophie; Grunwald, Armin [Karlsruhe Institute of Technology (Germany). Inst. for Technology Assessment and Systems Analysis


    In Switzerland, a new site selection procedure is being implemented since 2008. This procedure, which is laid down in a 'sectoral plan', shows strong elements of public participation and transparency and can be considered a step away from the classical 'decide-announce-defend' approach in decision-making. This procedure tends towards a more governance-oriented approach based on ideas of 'civility' of decision-making. Despite this renewal, the Swiss case clearly shows that any kind of selection process has to be considered as a 'working compromise', which needs to be adapted when new challenges emerge.

  20. Arrhythmia as a cardiac manifestation in MELAS syndrome. (United States)

    Thomas, Tamara; Craigen, William J; Moore, Ryan; Czosek, Richard; Jefferies, John L


    A 44-year-old female with a diagnosis of mitochondrial myopathy, encephalopathy and stroke-like episodes (MELAS) syndrome had progressive left ventricular hypertrophy (LVH) on echocardiogram. A Holter monitor demonstrated episodes of non-sustained atrial tachycardia, a finding not been previously described in this population. This unique case of MELAS syndrome demonstrates the known associated cardiac manifestation of LVH and the new finding of atrial tachycardia which may represent the potential for subclinical arrhythmia in this population.

  1. Arrhythmia as a cardiac manifestation in MELAS syndrome

    Directory of Open Access Journals (Sweden)

    Tamara Thomas


    Full Text Available A 44-year-old female with a diagnosis of mitochondrial myopathy, encephalopathy and stroke-like episodes (MELAS syndrome had progressive left ventricular hypertrophy (LVH on echocardiogram. A Holter monitor demonstrated episodes of non-sustained atrial tachycardia, a finding not been previously described in this population. This unique case of MELAS syndrome demonstrates the known associated cardiac manifestation of LVH and the new finding of atrial tachycardia which may represent the potential for subclinical arrhythmia in this population.

  2. Region-Based 4D Tomographic Image Reconstruction: Application to Cardiac X-ray CT

    NARCIS (Netherlands)

    Eyndhoven, G. Van; Batenburg, K.J.; Sijbers, J.


    X-ray computed tomography (CT) is a powerful tool for noninvasive cardiac imaging. However, radiation dose is a major issue. In this paper, we propose an iterative reconstruction method that reduces the radiation dose without compromising image quality. This is achieved by exploiting prior knowledge

  3. Mitochondrial biogenesis: pharmacological approaches. (United States)

    Valero, Teresa


    Organelle biogenesis is concomitant to organelle inheritance during cell division. It is necessary that organelles double their size and divide to give rise to two identical daughter cells. Mitochondrial biogenesis occurs by growth and division of pre-existing organelles and is temporally coordinated with cell cycle events [1]. However, mitochondrial biogenesis is not only produced in association with cell division. It can be produced in response to an oxidative stimulus, to an increase in the energy requirements of the cells, to exercise training, to electrical stimulation, to hormones, during development, in certain mitochondrial diseases, etc. [2]. Mitochondrial biogenesis is therefore defined as the process via which cells increase their individual mitochondrial mass [3]. Recent discoveries have raised attention to mitochondrial biogenesis as a potential target to treat diseases which up to date do not have an efficient cure. Mitochondria, as the major ROS producer and the major antioxidant producer exert a crucial role within the cell mediating processes such as apoptosis, detoxification, Ca2+ buffering, etc. This pivotal role makes mitochondria a potential target to treat a great variety of diseases. Mitochondrial biogenesis can be pharmacologically manipulated. This issue tries to cover a number of approaches to treat several diseases through triggering mitochondrial biogenesis. It contains recent discoveries in this novel field, focusing on advanced mitochondrial therapies to chronic and degenerative diseases, mitochondrial diseases, lifespan extension, mitohormesis, intracellular signaling, new pharmacological targets and natural therapies. It contributes to the field by covering and gathering the scarcely reported pharmacological approaches in the novel and promising field of mitochondrial biogenesis. There are several diseases that have a mitochondrial origin such as chronic progressive external ophthalmoplegia (CPEO) and the Kearns- Sayre syndrome (KSS

  4. Measuring cardiac efficiency using PET/MRI

    Energy Technology Data Exchange (ETDEWEB)

    Gullberg, Grand [Lawrence Berkeley National Laboratory (United States); Aparici, Carina Mari; Brooks, Gabriel [University of California San Francisco (United States); Liu, Jing; Guccione, Julius; Saloner, David; Seo, Adam Youngho; Ordovas, Karen Gomes [Lawrence Berkeley National Laboratory (United States)


    Heart failure (HF) is a complex syndrome that is projected by the American Heart Association to cost $160 billion by 2030. In HF, significant metabolic changes and structural remodeling lead to reduced cardiac efficiency. A normal heart is approximately 20-25% efficient measured by the ratio of work to oxygen utilization (1 ml oxygen = 21 joules). The heart requires rapid production of ATP where there is complete turnover of ATP every 10 seconds with 90% of ATP produced by mitochondrial oxidative metabolism requiring substrates of approximately 30% glucose and 65% fatty acids. In our preclinical PET/MRI studies in normal rats, we showed a negative correlation between work and the influx rate constant for 18FDG, confirming that glucose is not the preferred substrate at rest. However, even though fatty acid provides 9 kcal/gram compared to 4 kcal/gram for glucose, in HF the preferred energy source is glucose. PET/MRI offers the potential to study this maladapted mechanism of metabolism by measuring work in a region of myocardial tissue simultaneously with the measure of oxygen utilization, glucose, and fatty acid metabolism and to study cardiac efficiency in the etiology of and therapies for HF. MRI is used to measure strain and a finite element mechanical model using pressure measurements is used to estimate myofiber stress. The integral of strain times stress provides a measure of work which divided by energy utilization, estimated by the production of 11CO2 from intravenous injection of 11C-acetate, provides a measure of cardiac efficiency. Our project involves translating our preclinical research to the clinical application of measuring cardiac efficiency in patients. Using PET/MRI to develop technologies for studying myocardial efficiency in patients, provides an opportunity to relate cardiac work of specific tissue regions to metabolic substrates, and measure the heterogeneity of LV efficiency.

  5. S100A1: A Regulator of Striated Muscle Sarcoplasmic Reticulum Ca2+ Handling, Sarcomeric, and Mitochondrial Function

    Directory of Open Access Journals (Sweden)

    Mirko Völkers


    S100A1 has further been detected at different sites within the cardiac sarcomere indicating potential roles in myofilament function. More recently, a study reported a mitochondrial location of S100A1 in cardiomyocytes. Additionally, normalizing the level of S100A1 protein by means of viral cardiac gene transfer in animal heart failure models resulted in a disrupted progression towards cardiac failure and enhanced survival. This brief review is confined to the physiological and pathophysiological relevance of S100A1 in cardiac and skeletal muscle Ca2+ handling with a particular focus on its potential as a molecular target for future therapeutic interventions.

  6. Maternal High Fat Diet Alters Skeletal Muscle Mitochondrial Catalytic Activity in Adult Male Rat Offspring (United States)

    Pileggi, Chantal A.; Hedges, Christopher P.; Segovia, Stephanie A.; Markworth, James F.; Durainayagam, Brenan R.; Gray, Clint; Zhang, Xiaoyuan D.; Barnett, Matthew P. G.; Vickers, Mark H.; Hickey, Anthony J. R.; Reynolds, Clare M.; Cameron-Smith, David


    A maternal high-fat (HF) diet during pregnancy can lead to metabolic compromise, such as insulin resistance in adult offspring. Skeletal muscle mitochondrial dysfunction is one mechanism contributing to metabolic impairments in insulin resistant states. Therefore, the present study aimed to investigate whether mitochondrial dysfunction is evident in metabolically compromised offspring born to HF-fed dams. Sprague-Dawley dams were randomly assigned to receive a purified control diet (CD; 10% kcal from fat) or a high fat diet (HFD; 45% kcal from fat) for 10 days prior to mating, throughout pregnancy and during lactation. From weaning, all male offspring received a standard chow diet and soleus muscle was collected at day 150. Expression of the mitochondrial transcription factors nuclear respiratory factor-1 (NRF1) and mitochondrial transcription factor A (mtTFA) were downregulated in HF offspring. Furthermore, genes encoding the mitochondrial electron transport system (ETS) respiratory complex subunits were suppressed in HF offspring. Moreover, protein expression of the complex I subunit, NDUFB8, was downregulated in HF offspring (36%), which was paralleled by decreased maximal catalytic linked activity of complex I and III (40%). Together, these results indicate that exposure to a maternal HF diet during development may elicit lifelong mitochondrial alterations in offspring skeletal muscle. PMID:27917127

  7. United Mitochondrial Disease Foundation (United States)

    ... to Mitochondrial Disease FAQ's MitoFirst Handbook More Information Mito 101 Symposium Archives Get Connected Find an Event Adult Advisory Council Team Ask The Mito Doc Grand Rounds Kids & Teens Medical Child Abuse ...

  8. Testosterone replacement attenuates mitochondrial damage in a rat model of myocardial infarction. (United States)

    Wang, Fengyue; Yang, Jing; Sun, Junfeng; Dong, Yanli; Zhao, Hong; Shi, Hui; Fu, Lu


    Testosterone can affect cardiovascular disease, but its effects on mitochondrial dynamics in the post-infarct myocardium remain unclear. To observe the effects of testosterone replacement, a rat model of castration-myocardial infarction (MI) was established by ligating the left anterior descending coronary artery 2 weeks after castration with or without testosterone treatment. Expression of mitochondrial fission and fusion proteins was detected by western blot and immunofluorescence 14 days after MI. Cardiac function, myocardial inflammatory infiltration and fibrosis, cardiomyocyte apoptosis, mitochondrial microstructure, and ATP levels were also assessed. Compared with MI rats, castrated rats showed aggravated mitochondrial and myocardial insults, including mitochondrial swelling and disordered arrangement; loss of cristae, reduced mitochondrial length; decreased ATP levels; cardiomyocyte apoptosis; and impaired cardiac function. Results of western blotting analyses indicated that castration downregulated peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1A) and mitofusin 2, but upregulated dynamin-related protein 1. The results were also supported by results obtained using immunofluorescence. However, these detrimental effects were reversed by testosterone supplementation, which also elevated the upstream AMP-activated protein kinase (AMPK) activation of PGC1A. Thus, testosterone can protect mitochondria in the post-infarct myocardium, partly via the AMPK-PGC1A pathway, thereby decreasing mitochondrial dysfunction and cardiomyocyte apoptosis. The effects of testosterone were confirmed by the results of ELISA analyses.

  9. Impaired Cerebral Mitochondrial Oxidative Phosphorylation Function in a Rat Model of Ventricular Fibrillation and Cardiopulmonary Resuscitation

    Directory of Open Access Journals (Sweden)

    Jun Jiang


    Full Text Available Postcardiac arrest brain injury significantly contributes to mortality and morbidity in patients suffering from cardiac arrest (CA. Evidence that shows that mitochondrial dysfunction appears to be a key factor in tissue damage after ischemia/reperfusion is accumulating. However, limited data are available regarding the cerebral mitochondrial dysfunction during CA and cardiopulmonary resuscitation (CPR and its relationship to the alterations of high-energy phosphate. Here, we sought to identify alterations of mitochondrial morphology and oxidative phosphorylation function as well as high-energy phosphates during CA and CPR in a rat model of ventricular fibrillation (VF. We found that impairment of mitochondrial respiration and partial depletion of adenosine triphosphate (ATP and phosphocreatine (PCr developed in the cerebral cortex and hippocampus following a prolonged cardiac arrest. Optimal CPR might ameliorate the deranged phosphorus metabolism and preserve mitochondrial function. No obvious ultrastructural abnormalities of mitochondria have been found during CA. We conclude that CA causes cerebral mitochondrial dysfunction along with decay of high-energy phosphates, which would be mitigated with CPR. This study may broaden our understanding of the pathogenic processes underlying global cerebral ischemic injury and provide a potential therapeutic strategy that aimed at preserving cerebral mitochondrial function during CA.

  10. The plant mitochondrial proteome

    DEFF Research Database (Denmark)

    Millar, A.H.; Heazlewood, J.L.; Kristensen, B.K.


    The plant mitochondrial proteome might contain as many as 2000-3000 different gene products, each of which might undergo post-translational modification. Recent studies using analytical methods, such as one-, two- and three-dimensional gel electrophoresis and one- and two-dimensional liquid...... context to be defined for them. There are indications that some of these proteins add novel activities to mitochondrial protein complexes in plants....

  11. Mitochondrial protection by resveratrol. (United States)

    Ungvari, Zoltan; Sonntag, William E; de Cabo, Rafael; Baur, Joseph A; Csiszar, Anna


    Mitochondrial dysfunction and oxidative stress are thought to play important roles in mammalian aging. Resveratrol is a plant-derived polyphenol that exerts diverse antiaging activities, mimicking some of the molecular and functional effects of dietary restriction. This review focuses on the molecular mechanisms underlying the mitochondrial protective effects of resveratrol, which could be exploited for the prevention or amelioration of age-related diseases in the elderly.

  12. Diffusion-reaction compromise the polymorphs of precipitated calcium carbonate

    Institute of Scientific and Technical Information of China (English)

    Han Wang; Wenlai Huang; Yongsheng Han


    Diffusion is seldom considered by chemists and materialists in the preparation of materials while it plays an important role in the field of chemical engineering.If we look at crystallization at the atomic level,crystal growth in a solution starts from the diffusion of ions to the growing surface followed by the incorporation of ions into its lattice.Diffusion can be a rate determining step for the growth of crystals.In this paper,we take the crystallization of calcium carbonate as an example to illustrate the microscopic processes of diffusion and reaction and their compromising influence on the morphology of the crystals produced.The diffusion effect is studied in a specially designed three-cell reactor.Experiments show that a decrease of diffusion leads to retardation of supersaturation and the formation of a continuous concentration gradient in the reaction cell,thus promoting the formation of cubic calcite particles.The reaction rate is regulated by temperature.Increase of reaction rate favors the formation of needle-like aragonite particles.When diffusion and reaction play joint roles in the reaction system,their compromise dominates the formation of products,leading to a mixture of cubic and needle-like particles with a controllable ratio.Since diffusion and reaction are universal factors in the preparation of materials,the finding of this paper could be helpful in the controlled synthesis of other materials.

  13. Cardiac Procedures and Surgeries (United States)

    ... Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Cardiac Procedures and Surgeries Updated:Sep 16,2016 If you've had ... degree of coronary artery disease (CAD) you have. Cardiac Procedures and Surgeries Angioplasty Also known as Percutaneous Coronary Interventions [PCI], ...

  14. [Advances in cardiac pacing]. (United States)

    de Carranza, María-José Sancho-Tello; Fidalgo-Andrés, María Luisa; Ferrer, José Martínez; Mateas, Francisco Ruiz


    This article contains a review of the current status of remote monitoring and follow-up involving cardiac pacing devices and of the latest developments in cardiac resynchronization therapy. In addition, the most important articles published in the last year are discussed.

  15. MELAS syndrome and cardiomyopathy: linking mitochondrial function to heart failure pathogenesis. (United States)

    Hsu, Ying-Han R; Yogasundaram, Haran; Parajuli, Nirmal; Valtuille, Lucas; Sergi, Consolato; Oudit, Gavin Y


    Heart failure remains an important clinical burden, and mitochondrial dysfunction plays a key role in its pathogenesis. The heart has a high metabolic demand, and mitochondrial function is a key determinant of myocardial performance. In mitochondrial disorders, hypertrophic remodeling is the early pattern of cardiomyopathy with progression to dilated cardiomyopathy, conduction defects and ventricular pre-excitation occurring in a significant proportion of patients. Cardiac dysfunction occurs in approximately a third of patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome, a stereotypical example of a mitochondrial disorder leading to a cardiomyopathy. We performed unique comparative ultrastructural and gene expression in a MELAS heart compared with non-failing controls. Our results showed a remarkable increase in mitochondrial inclusions and increased abnormal mitochondria in MELAS cardiomyopathy coupled with variable sarcomere thickening, heterogeneous distribution of affected cardiomyocytes and a greater elevation in the expression of disease markers. Investigation and management of patients with mitochondrial cardiomyopathy should follow the well-described contemporary heart failure clinical practice guidelines and include an important role of medical and device therapies. Directed metabolic therapy is lacking, but current research strategies are dedicated toward improving mitochondrial function in patients with mitochondrial disorders.

  16. Inhibition of Drp1 attenuates mitochondrial damage and myocardial injury in Coxsackievirus B3 induced myocarditis. (United States)

    Lin, Lin; Zhang, Ming; Yan, Rui; Shan, Hu; Diao, Jiayu; Wei, Jin


    Viral myocarditis (VMC) is closely related to apoptosis, oxidative stress, innate immunity, and energy metabolism, which are all linked to mitochondrial dysfunction. A close nexus between mitochondrial dynamics and cardiovascular disease with mitochondrial dysfunction has been deeply researched, but there is still no relevant report in viral myocarditis. In this study, we aimed to explore the role of Dynamin-related protein 1 (Drp1)-linked mitochondrial fission in VMC. Mice were inoculated with the Coxsackievirus B3 (CVB3) and treated with mdivi1 (a Drp1 inhibitor). Protein expression of Drp1 was increased in mitochondria while decreased in cytoplasm and accompanied by excessive mitochondrial fission in VMC mice. In addition, midivi1 treatment attenuate inflammatory cells infiltration in myocardium of the mice, serum Cardiac troponin I (CTnI) and Creatine kinase-MB (CK-MB) level. Mdivi1 also could improved the survival rate of mice and mitochondrial dysfunction reflected as the up-regulated mitochondrial marker enzymatic activities of succinate dehydrogenase (SDH), cytochrome c oxidase (COX) and mitochondrial membrane potential (MMP). At the same time, mdivi1 rescued the body weight loss, myocardial injury and apoptosis of cardiomyocyte. Furthermore, decease in LVEDs and increase in EF and FS were detected by echocardiogram, which indicated the improved myocardial function. Thus, Drp1-linked excessive mitochondrial fission contributed to VMC and midivi1 may be a potential therapeutic approach.

  17. Biomaterials for cardiac regeneration

    CERN Document Server

    Ruel, Marc


    This book offers readers a comprehensive biomaterials-based approach to achieving clinically successful, functionally integrated vasculogenesis and myogenesis in the heart. Coverage is multidisciplinary, including the role of extracellular matrices in cardiac development, whole-heart tissue engineering, imaging the mechanisms and effects of biomaterial-based cardiac regeneration, and autologous bioengineered heart valves. Bringing current knowledge together into a single volume, this book provides a compendium to students and new researchers in the field and constitutes a platform to allow for future developments and collaborative approaches in biomaterials-based regenerative medicine, even beyond cardiac applications. This book also: Provides a valuable overview of the engineering of biomaterials for cardiac regeneration, including coverage of combined biomaterials and stem cells, as well as extracellular matrices Presents readers with multidisciplinary coverage of biomaterials for cardiac repair, including ...

  18. Mathematical cardiac electrophysiology

    CERN Document Server

    Colli Franzone, Piero; Scacchi, Simone


    This book covers the main mathematical and numerical models in computational electrocardiology, ranging from microscopic membrane models of cardiac ionic channels to macroscopic bidomain, monodomain, eikonal models and cardiac source representations. These advanced multiscale and nonlinear models describe the cardiac bioelectrical activity from the cell level to the body surface and are employed in both the direct and inverse problems of electrocardiology. The book also covers advanced numerical techniques needed to efficiently carry out large-scale cardiac simulations, including time and space discretizations, decoupling and operator splitting techniques, parallel finite element solvers. These techniques are employed in 3D cardiac simulations illustrating the excitation mechanisms, the anisotropic effects on excitation and repolarization wavefronts, the morphology of electrograms in normal and pathological tissue and some reentry phenomena. The overall aim of the book is to present rigorously the mathematica...

  19. Peripheral neuropathy in mitochondrial disorders. (United States)

    Pareyson, Davide; Piscosquito, Giuseppe; Moroni, Isabella; Salsano, Ettore; Zeviani, Massimo


    Why is peripheral neuropathy common but mild in many mitochondrial disorders, and why is it, in some cases, the predominant or only manifestation? Although this question remains largely unanswered, recent advances in cellular and molecular biology have begun to clarify the importance of mitochondrial functioning and distribution in the peripheral nerve. Mutations in proteins involved in mitochondrial dynamics (ie, fusion and fission) frequently result in a Charcot-Marie-Tooth phenotype. Peripheral neuropathies with different phenotypic presentations occur in mitochondrial diseases associated with abnormalities in mitochondrial DNA replication and maintenance, or associated with defects in mitochondrial respiratory chain complex V. Our knowledge of mitochondrial disorders is rapidly growing as new nuclear genes are identified and new phenotypes described. Early diagnosis of mitochondrial disorders, essential to provide appropriate genetic counselling, has become crucial in a few treatable conditions. Recognising and diagnosing an underlying mitochondrial defect in patients presenting with peripheral neuropathy is therefore of paramount importance.

  20. Ocular manifestations of mitochondrial disease

    Directory of Open Access Journals (Sweden)

    S. D. Mathebula


    Full Text Available Mitochondrial disease caused by mutations in mitochondrial DNA is recognized as one of the most common causes of inherited neurological disease. Neuro-ophthalmic manifestations are a common feature of mitochondrial disease.  Optic atrophy causing central visual loss is the dominant feature of mitochondrial DNA diseases. Nystagmus is also encountered in mitochondrial disease.Although optometrists are not involved with the management of mitochondrial disease, they are likely to see more patients with this disease. Oph-thalmic examination forms part of the clinical assessment of mitochondrial disease. Mitochondrial disease should be suspected in any patient with unexplained optic neuropathy, ophthalmoplegia, pigmentary retinopathy or retrochiasmal visual loss. Despite considerable advances in the under-standing of mitochondrial genetics and the patho-genesis of mtDNA diseases, no effective treatment options are currently available for patients withmitochondrial dysfunction. (S Afr Optom 201271(1 46-50

  1. The Role of Mitochondrial Non-Enzymatic Protein Acylation in Ageing (United States)

    Hong, Shin Yee; Ng, Li Theng; Ng, Li Fang; Inoue, Takao; Tolwinski, Nicholas S.; Hagen, Thilo; Gruber, Jan


    In recent years, various large-scale proteomic studies have demonstrated that mitochondrial proteins are highly acylated, most commonly by addition of acetyl and succinyl groups. These acyl modifications may be enzyme catalysed but can also be driven non-enzymatically. The latter mechanism is promoted in mitochondria due to the nature of the mitochondrial microenvironment, which is alkaline and contains high concentrations of acyl-CoA species. Protein acylation may modify enzyme activity, typically inhibiting it. We posited that organismal ageing might be accompanied by an accumulation of acylated proteins, especially in mitochondria, and that this might compromise mitochondrial function and contribute to ageing. In this study, we used R. norvegicus, C. elegans and D. melanogaster to compare the acylation status of mitochondrial proteins between young and old animals. We observed a specific age-dependent increase in protein succinylation in worms and flies but not in rat. Rats have two substrate-specific mitochondrial deacylases, SIRT3 and SIRT5 while both flies and worms lack these enzymes. We propose that accumulation of mitochondrial protein acylation contributes to age-dependent mitochondrial functional decline and that SIRT3 and SIRT5 enzymes may promote longevity through regulation of mitochondrial protein acylation during ageing. PMID:28033361

  2. Mitochondrial diseases: therapeutic approaches. (United States)

    DiMauro, Salvatore; Mancuso, Michelangelo


    Therapy of mitochondrial encephalomyopathies (defined restrictively as defects of the mitochondrial respiratory chain) is woefully inadequate, despite great progress in our understanding of the molecular bases of these disorders. In this review, we consider sequentially several different therapeutic approaches. Palliative therapy is dictated by good medical practice and includes anticonvulsant medication, control of endocrine dysfunction, and surgical procedures. Removal of noxious metabolites is centered on combating lactic acidosis, but extends to other metabolites. Attempts to bypass blocks in the respiratory chain by administration of electron acceptors have not been successful, but this may be amenable to genetic engineering. Administration of metabolites and cofactors is the mainstay of real-life therapy and is especially important in disorders due to primary deficiencies of specific compounds, such as carnitine or coenzyme Q10. There is increasing interest in the administration of reactive oxygen species scavengers both in primary mitochondrial diseases and in neurodegenerative diseases directly or indirectly related to mitochondrial dysfunction. Aerobic exercise and physical therapy prevent or correct deconditioning and improve exercise tolerance in patients with mitochondrial myopathies due to mitochondrial DNA (mtDNA) mutations. Gene therapy is a challenge because of polyplasmy and heteroplasmy, but interesting experimental approaches are being pursued and include, for example, decreasing the ratio of mutant to wild-type mitochondrial genomes (gene shifting), converting mutated mtDNA genes into normal nuclear DNA genes (allotopic expression), importing cognate genes from other species, or correcting mtDNA mutations with specific restriction endonucleases. Germline therapy raises ethical problems but is being considered for prevention of maternal transmission of mtDNA mutations. Preventive therapy through genetic counseling and prenatal diagnosis is

  3. Cardiac Paraganglioma Arising From the Right Atrioventricular Groove in a Paraganglioma-Pheochromocytoma Family Syndrome With Evidence of SDHB Gene Mutation: An Unusual Presentation. (United States)

    Del Forno, Benedetto; Zingaro, Carlo; Di Palma, Enza; Capestro, Filippo; Rescigno, Giuseppe; Torracca, Lucia


    Primary cardiac paragangliomas are extremely rare. Recently this neoplasm has been associated with a familiar syndrome as a result of mutation of genes that encode proteins in the mitochondrial complex II. We report a case of a 46-year-old woman having cases of vertebral paraganglioma in her family showing an unusual anatomic and clinical presentation of cardiac paraganglioma and expressing a genetic mutation never associated before with cardiac localization of this neoplasm.

  4. [Amputation or reconstruction of a circulatory compromised severely injured extremity?]. (United States)

    Høiness, P; Røise, O


    18 patients treated with primary or secondary amputations after severe lower limb open fractures were studied. All limbs had clinical signs of a compromised circulation at the primary evaluation. The various injuries are described and discussed with respect to the general guidelines for primary amputation. The Mangled Extremity Severity Score (MESS) and Nerve, Ischemia, Soft tissues, Skeletal, Shock, Age (NISSSA) scores were calculated. In view of the described injuries, primary amputation was indicated in ten patients according to the general recommendations, 11 patients according to NISSSA and 15 patients according to MESS. Delayed amputation leads t a significantly (p = 0.005) higher number of operative procedures than early amputation (9.2 vs. 2.9 treatments). The decision of whether to amputate or not should be based on sound clinical judgement, but injury scores such as MESS and NISSSA may be helpful.

  5. Glutathione synthesis is compromised in erythrocytes from individuals with HIV. (United States)

    Morris, Devin; Ly, Judy; Chi, Po-Ting; Daliva, John; Nguyen, Truongson; Soofer, Charleen; Chen, Yung C; Lagman, Minette; Venketaraman, Vishwanath


    We demonstrated that the levels of enzymes responsible for the synthesis of glutathione (GSH) such as glutathione synthase (GSS), glutamate-cysteine ligase-catalytic subunit (GCLC), and glutathione reductase (GSR) were significantly reduced in the red blood cells (RBCs) isolated from individuals with human immunodeficiency virus (HIV) infection and this reduction correlated with decreased levels of intracellular GSH. GSH content in RBCs can be used as a marker for increased overall oxidative stress and immune dysfunctions caused by HIV infection. Our data supports our hypothesis that compromised levels of GSH in HIV infected individuals' is due to decreased levels of GSH-synthetic enzymes. The role of GSH in combating oxidative stress and improving the functions of immune cells in HIV patients' indicates the benefit of an antioxidant supplement which can reduce the cellular damage and promote the functions of immune cells.

  6. Compromising Tor Anonymity Exploiting P2P Information Leakage

    CERN Document Server

    Manils, Pere; Blond, Stevens Le; Kaafar, Mohamed Ali; Castelluccia, Claude; Legout, Arnaud; Dabbous, Walid


    Privacy of users in P2P networks goes far beyond their current usage and is a fundamental requirement to the adoption of P2P protocols for legal usage. In a climate of cold war between these users and anti-piracy groups, more and more users are moving to anonymizing networks in an attempt to hide their identity. However, when not designed to protect users information, a P2P protocol would leak information that may compromise the identity of its users. In this paper, we first present three attacks targeting BitTorrent users on top of Tor that reveal their real IP addresses. In a second step, we analyze the Tor usage by BitTorrent users and compare it to its usage outside of Tor. Finally, we depict the risks induced by this de-anonymization and show that users' privacy violation goes beyond BitTorrent traffic and contaminates other protocols such as HTTP.

  7. Sarcoidosis with Major Airway, Vascular and Nerve Compromise

    Directory of Open Access Journals (Sweden)

    Hiroshi Sekiguchi


    Full Text Available The present report describes a 60-year-old Caucasian woman who presented with progressive dyspnea, cough and wheeze. A computed tomography scan of the chest showed innumerable bilateral inflammatory pulmonary nodules with bronchovascular distribution and a mediastinal and hilar infiltrative process with calcified lymphadenopathy leading to narrowing of lobar bronchi and pulmonary arteries. An echocardiogram revealed pulmonary hypertension. Bronchoscopy showed left vocal cord paralysis and significant narrowing of the bilateral bronchi with mucosal thickening and multiple nodules. Transbronchial biopsy was compatible with sarcoidosis. Despite balloon angioplasty of the left lower lobe and pulmonary artery, and medical therapy with oral corticosteroids, her symptoms did not significantly improve. To the authors’ knowledge, the present report describes the first case of pulmonary sarcoidosis resulting in major airway, vascular and nerve compromise due to compressive lymphadenopathy and suspected concurrent granulomatous infiltration. Its presentation mimicked idiopathic mediastinal fibrosis.

  8. Enhanced susceptibility to predation in corals of compromised condition

    Directory of Open Access Journals (Sweden)

    Allan J. Bright


    Full Text Available The marine gastropod, Coralliophila abbreviata, is an obligate corallivore that causes substantial mortality in Caribbean Acropora spp. Considering the imperiled status of Acropora cervicornis and A. palmata, a better understanding of ecological interactions resulting in tissue loss may enable more effective conservation strategies. We examined differences in susceptibility of A. cervicornis to C. abbreviata predation based on coral tissue condition. Coral tissue condition was a strong determinant of snail prey choice, with snails preferring A. cervicornis fragments that were diseased or mechanically damaged over healthy fragments. In addition, snails always chose fragments undergoing active predation by another snail, while showing no preference for a non-feeding snail when compared with an undisturbed prey fragment. These results indicate that the condition of A. cervicornis prey influenced foraging behavior of C. abbreviata, creating a potential feedback that may exacerbate damage from predation in coral populations compromised by other types of disturbance.

  9. Enhanced susceptibility to predation in corals of compromised condition. (United States)

    Bright, Allan J; Cameron, Caitlin M; Miller, Margaret W


    The marine gastropod, Coralliophila abbreviata, is an obligate corallivore that causes substantial mortality in Caribbean Acropora spp. Considering the imperiled status of Acropora cervicornis and A. palmata, a better understanding of ecological interactions resulting in tissue loss may enable more effective conservation strategies. We examined differences in susceptibility of A. cervicornis to C. abbreviata predation based on coral tissue condition. Coral tissue condition was a strong determinant of snail prey choice, with snails preferring A. cervicornis fragments that were diseased or mechanically damaged over healthy fragments. In addition, snails always chose fragments undergoing active predation by another snail, while showing no preference for a non-feeding snail when compared with an undisturbed prey fragment. These results indicate that the condition of A. cervicornis prey influenced foraging behavior of C. abbreviata, creating a potential feedback that may exacerbate damage from predation in coral populations compromised by other types of disturbance.

  10. Food irradiation: Special solutions for the immuno-compromised (United States)

    Mohácsi-Farkas, Csilla


    Safety of food is particularly important for immuno-compromised patients, because these people are vulnerable to all sorts of infectious complications and foodborne pathogens as well, and even organisms normally considered non-pathogenic may cause problems. According to the guidelines published by the FDA, immunocompromised patients have to avoid high-risk foods, and advised to consume only pasteurized juice, milk or cheese, and well-cooked eggs, poultry, meat and fish. In the frame of an IAEA CRP the objective was to develop, in collaborations with the healthcare community, the use of irradiation to increase the variety, availability and acceptability of foods for immunocompromised, for example irradiated fresh produce (fruits, vegetables, salads) and ready-to-eat meals. Further aim was to widen the acceptance of irradiated foods by the healthcare and regulatory communities.

  11. Protecting Privacy of Shared Epidemiologic Data without Compromising Analysis Potential

    Directory of Open Access Journals (Sweden)

    John Cologne


    Full Text Available Objective. Ensuring privacy of research subjects when epidemiologic data are shared with outside collaborators involves masking (modifying the data, but overmasking can compromise utility (analysis potential. Methods of statistical disclosure control for protecting privacy may be impractical for individual researchers involved in small-scale collaborations. Methods. We investigated a simple approach based on measures of disclosure risk and analytical utility that are straightforward for epidemiologic researchers to derive. The method is illustrated using data from the Japanese Atomic-bomb Survivor population. Results. Masking by modest rounding did not adequately enhance security but rounding to remove several digits of relative accuracy effectively reduced the risk of identification without substantially reducing utility. Grouping or adding random noise led to noticeable bias. Conclusions. When sharing epidemiologic data, it is recommended that masking be performed using rounding. Specific treatment should be determined separately in individual situations after consideration of the disclosure risks and analysis needs.

  12. Glutathione synthesis is compromised in erythrocytes from individuals with HIV

    Directory of Open Access Journals (Sweden)

    Vishwanath eVenketaraman


    Full Text Available We demonstrated that the levels of enzymes responsible for the synthesis of glutathione (GSH such as glutathione synthase (GSS, glutamate-cysteine ligase-catalytic subunit (GCLC and glutathione reductase (GSR were significantly reduced in the red blood cells (RBCs isolated from individuals with human immunodeficiency virus (HIV infection and this reduction correlated with decreased levels of intracellular GSH. GSH content in RBCs can be used as a marker for increased overall oxidative stress and immune dysfunctions caused by HIV infection. Our data supports our hypothesis that compromised levels of GSH in HIV infected individuals’ is due to decreased levels of GSH-synthetic enzymes. The role of GSH in combating oxidative stress and improving the functions of immune cells in HIV patients’ indicates the benefit of an antioxidant supplement which can reduce the cellular damage and promote the functions of immune cells.

  13. Mitigating reptile road mortality: fence failures compromise ecopassage effectiveness.

    Directory of Open Access Journals (Sweden)

    James H Baxter-Gilbert

    Full Text Available Roadways pose serious threats to animal populations. The installation of roadway mitigation measures is becoming increasingly common, yet studies that rigorously evaluate the effectiveness of these conservation tools remain rare. A highway expansion project in Ontario, Canada included exclusion fencing and ecopassages as mitigation measures designed to offset detrimental effects to one of the most imperial groups of vertebrates, reptiles. Taking a multispecies approach, we used a Before-After-Control-Impact study design to compare reptile abundance on the highway before and after mitigation at an Impact site and a Control site from 1 May to 31 August in 2012 and 2013. During this time, radio telemetry, wildlife cameras, and an automated PIT-tag reading system were used to monitor reptile movements and use of ecopassages. Additionally, a willingness to utilize experiment was conducted to quantify turtle behavioral responses to ecopassages. We found no difference in abundance of turtles on the road between the un-mitigated and mitigated highways, and an increase in the percentage of both snakes and turtles detected dead on the road post-mitigation, suggesting that the fencing was not effective. Although ecopassages were used by reptiles, the number of crossings through ecopassages was lower than road-surface crossings. Furthermore, turtle willingness to use ecopassages was lower than that reported in previous arena studies, suggesting that effectiveness of ecopassages may be compromised when alternative crossing options are available (e.g., through holes in exclusion structures. Our rigorous evaluation of reptile roadway mitigation demonstrated that when exclusion structures fail, the effectiveness of population connectivity structures is compromised. Our project emphasizes the need to design mitigation measures with the biology and behavior of the target species in mind, to implement mitigation designs in a rigorous fashion, and quantitatively

  14. Methamphetamine compromises gap junctional communication in astrocytes and neurons. (United States)

    Castellano, Paul; Nwagbo, Chisom; Martinez, Luis R; Eugenin, Eliseo A


    Methamphetamine (meth) is a central nervous system (CNS) stimulant that results in psychological and physical dependency. The long-term effects of meth within the CNS include neuronal plasticity changes, blood-brain barrier compromise, inflammation, electrical dysfunction, neuronal/glial toxicity, and an increased risk to infectious diseases including HIV. Most of the reported meth effects in the CNS are related to dysregulation of chemical synapses by altering the release and uptake of neurotransmitters, especially dopamine, norepinephrine, and epinephrine. However, little is known about the effects of meth on connexin (Cx) containing channels, such as gap junctions (GJ) and hemichannels (HC). We examined the effects of meth on Cx expression, function, and its role in NeuroAIDS. We found that meth altered Cx expression and localization, decreased GJ communication between neurons and astrocytes, and induced the opening of Cx43/Cx36 HC. Furthermore, we found that these changes in GJ and HC induced by meth treatment were mediated by activation of dopamine receptors, suggesting that dysregulation of dopamine signaling induced by meth is essential for GJ and HC compromise. Meth-induced changes in GJ and HC contributed to amplified CNS toxicity by dysregulating glutamate metabolism and increasing the susceptibility of neurons and astrocytes to bystander apoptosis induced by HIV. Together, our results indicate that connexin containing channels, GJ and HC, are essential in the pathogenesis of meth and increase the sensitivity of the CNS to HIV CNS disease. Methamphetamine (meth) is an extremely addictive central nervous system stimulant. Meth reduced gap junctional (GJ) communication by inducing internalization of connexin-43 (Cx43) in astrocytes and reducing expression of Cx36 in neurons by a mechanism involving activation of dopamine receptors (see cartoon). Meth-induced changes in Cx containing channels increased extracellular levels of glutamate and resulted in higher

  15. Treatment of Lung Cancer in Medically Compromised Patients. (United States)

    Crawford, Jeffrey; Wheatley-Price, Paul; Feliciano, Josephine Louella


    Outcomes for patients with lung cancer have been improved substantially through the integration of surgery, radiation, and systemic therapy for patients with early-stage disease. Meanwhile, advances in our understanding of molecular mechanisms have substantially advanced our treatment of patients with advanced lung cancer through the introduction of targeted therapies, immune approaches, improvements in chemotherapy, and better supportive care. However, the majority of these advances have occurred among patients with good functional status, normal organ function, and with the social and economic support systems to be able to benefit most from these treatments. The aim of this article is to bring greater attention to management of lung cancer in patients who are medically compromised, which remains a major barrier to care delivery. Impaired performance status is associated with poor outcomes and correlates with the high prevalence of cachexia among patients with advanced lung cancer. CT imaging is emerging as a research tool to quantify muscle loss in patients with cancer, and new therapeutics are on the horizon that may provide important adjunctive therapy in the future. The benefits of cancer therapy for patients with organ failure are poorly understood because of their exclusion from clinical trials. The availability of targeted therapy and immunotherapy may provide alternatives that may be easier to deliver in this population, but clinical trials of these new agents in this population are vital. Patients with lower socioeconomic status are disproportionately affected by lung cancer because of higher rates of tobacco addiction and the impact of socioeconomic status on delay in diagnosis, treatment, and outcomes. For all patients who are medically compromised with lung cancer, multidisciplinary approaches are particularly needed to evaluate these patients and to incorporate rapidly changing therapeutics to improve outcomes.

  16. Erythropoietin treatment enhances mitochondrial function in human skeletal muscle

    Directory of Open Access Journals (Sweden)

    Ulla ePlenge


    Full Text Available Abstract Erythropoietin (Epo treatment has been shown to induce mitochondrial biogenesis in cardiac muscle along with enhanced mitochondrial capacity in mice. We hypothesized that recombinant human Epo (rhEpo treatment enhances skeletal muscle mitochondrial oxidative phosphorylation (OXPHOS capacity in humans. In six healthy volunteers rhEpo was administered by sub-cutaneous injection over eight weeks with oral iron (100 mg supplementation taken daily. Mitochondrial OXPHOS was quantified by high-resolution respirometry in saponin-permeabilized muscle fibers obtained from biopsies of the vastus lateralis before and after rhEpo treatment. OXPHOS was determined with the mitochondrial complex I substrates malate, glutamate, pyruvate and complex II substrate succinate in the presence of saturating ADP concentrations, while maximal electron transport capacity (ETS was assessed by addition of an uncoupler. rhEpo treatment increased OXPHOS (from 92±5 to 113±7 and ETS (107±4 to 143±14, P<0.05, demonstrating that Epo treatment induces an upregulation of OXPHOS and ETS in human skeletal muscle.

  17. Cardiac tumors: echo assessment. (United States)

    Mankad, Rekha; Herrmann, Joerg


    Cardiac tumors are exceedingly rare (0.001-0.03% in most autopsy series). They can be present anywhere within the heart and can be attached to any surface or be embedded in the myocardium or pericardial space. Signs and symptoms are nonspecific and highly variable related to the localization, size and composition of the cardiac mass. Echocardiography, typically performed for another indication, may be the first imaging modality alerting the clinician to the presence of a cardiac mass. Although echocardiography cannot give the histopathology, certain imaging features and adjunctive tools such as contrast imaging may aid in the differential diagnosis as do the adjunctive clinical data and the following principles: (1) thrombus or vegetations are the most likely etiology, (2) cardiac tumors are mostly secondary and (3) primary cardiac tumors are mostly benign. Although the finding of a cardiac mass on echocardiography may generate confusion, a stepwise approach may serve well practically. Herein, we will review such an approach and the role of echocardiography in the assessment of cardiac masses.

  18. Neurological mitochondrial cytopathies.

    Directory of Open Access Journals (Sweden)

    Mehndiratta M


    Full Text Available The mitochondrial cytopathies are genetically and phenotypically heterogeneous group of disorders caused by structural and functional abnormalities in mitochondria. To the best of our knowledge, there are very few studies published from India till date. Selected and confirmed fourteen cases of neurological mitochondrial cytopathies with different clinical syndromes admitted between 1997 and 2000 are being reported. There were 8 male and 6 female patients. The mean age was 24.42+/-11.18 years (range 4-40 years. Twelve patients could be categorized into well-defined syndromes, while two belonged to undefined group. In the defined syndrome categories, three patients had MELAS (mitochondrial encephalopathy, lactic acidosis and stroke like episodes, three had MERRF (myoclonic epilepsy and ragged red fibre myopathy, three cases had KSS (Kearns-Sayre Syndrome and three were diagnosed to be suffering from mitochondrial myopathy. In the uncategorized group, one case presented with paroxysmal kinesogenic dystonia and the other manifested with generalized chorea alone. Serum lactic acid level was significantly increased in all the patients (fasting 28.96+/-4.59 mg%, post exercise 41.02+/-4.93 mg%. Muscle biopsy was done in all cases. Succinic dehydrogenase staining of muscle tissue showed subsarcolemmal accumulation of mitochondria in 12 cases. Mitochondrial DNA study could be performed in one case only and it did not reveal any mutation at nucleotides 3243 and 8344. MRI brain showed multiple infarcts in MELAS, hyperintensities in putaminal areas in chorea and bilateral cerebellar atrophy in MERRF.

  19. Hyperglycemia-Induced Inhibition of DJ-1 Expression Compromised the Effectiveness of Ischemic Postconditioning Cardioprotection in Rats

    Directory of Open Access Journals (Sweden)

    Min Liu


    Full Text Available Ischemia postconditioning (IpostC is an effective way to alleviate ischemia and reperfusion injury; however, the protective effects seem to be impaired in candidates with diabetes mellitus. To gain deep insight into this phenomenon, we explored the role of DJ-1, a novel oncogene, that may exhibit powerful antioxidant capacity in postconditioning cardioprotection in a rat model of myocardial ischemia reperfusion injury. Compared with normal group, cardiac DJ-1 was downregulated in diabetes. Larger postischemic infarct size as well as exaggeration of oxidative stress was observed, while IpostC reversed the above changes in normal but not in diabetic rats. DJ-1 was increased after ischemia and postconditioning contributed to a further elevation; however, no alteration of DJ-1 was documented in all subgroups of diabetic rats. Alteration of the cardioprotective PI3K/Akt signaling proteins may be responsible for the ineffectiveness of postconditioning in diabetes. There is a positive correlation relationship between p-Akt and DJ-1 but a negative correlation between infarct size and DJ-1, which may partially explain the interaction of DJ-1 and IpostC cardioprotection. Our result indicates a beneficial role of DJ-1 in myocardial ischemia reperfusion. Downregulation of cardiac DJ-1 may be responsible for the compromised diabetic heart responsiveness to IpostC cardioprotection.

  20. Biochemical indications of cerebral ischaemia and mitochondrial dysfunction in severe brain trauma analysed with regard to type of lesion

    DEFF Research Database (Denmark)

    Nordström, Carl-Henrik; Nielsen, Troels Halfeld; Schalén, Wilhelm


    ), cerebral haemorrhagic contusion (CHC) and no mass lesion (NML). Altogether about 150,000 biochemical analyses were performed during the initial 96 h after trauma. Compromised aerobic metabolism occurred during 38 % of the study period. The biochemical pattern indicating mitochondrial dysfunction was more...

  1. Increased intrinsic mitochondrial function in humans with mitochondrial haplogroup H

    DEFF Research Database (Denmark)

    Larsen, Steen; Díez-Sánchez, Carmen; Rabøl, Rasmus


    It has been suggested that human mitochondrial variants influence maximal oxygen uptake (VO2max). Whether mitochondrial respiratory capacity per mitochondrion (intrinsic activity) in human skeletal muscle is affected by differences in mitochondrial variants is not known. We recruited 54 males and...

  2. Mitochondrial fusion and inheritance of the mitochondrial genome. (United States)

    Takano, Hiroyoshi; Onoue, Kenta; Kawano, Shigeyuki


    Although maternal or uniparental inheritance of mitochondrial genomes is a general rule, biparental inheritance is sometimes observed in protists and fungi,including yeasts. In yeast, recombination occurs between the mitochondrial genomes inherited from both parents.Mitochondrial fusion observed in yeast zygotes is thought to set up a space for DNA recombination. In the last decade,a universal mitochondrial fusion mechanism has been uncovered, using yeast as a model. On the other hand, an alternative mitochondrial fusion mechanism has been identified in the true slime mold Physarum polycephalum.A specific mitochondrial plasmid, mF, has been detected as the genetic material that causes mitochondrial fusion in P. polycephalum. Without mF, fusion of the mitochondria is not observed throughout the life cycle, suggesting that Physarum has no constitutive mitochondrial fusion mechanism.Conversely, mitochondria fuse in zygotes and during sporulation with mF. The complete mF sequence suggests that one gene, ORF640, encodes a fusogen for Physarum mitochondria. Although in general, mitochondria are inherited uniparentally, biparental inheritance occurs with specific sexual crossing in P. polycephalum.An analysis of the transmission of mitochondrial genomes has shown that recombinations between two parental mitochondrial genomes require mitochondrial fusion,mediated by mF. Physarum is a unique organism for studying mitochondrial fusion.

  3. Guidelines for specialized nutritional and metabolic support in the critically-ill patient: Update. Consensus SEMICYUC-SENPE: Cardiac patient Recomendaciones para el soporte nutricional y metabólico especializado del paciente crítico: Actualización. Consenso SEMICYUC-SENPE: Paciente cardíaco


    F. J. Jiménez Jiménez; M. Cervera Montes; A. L. Blesa Malpica


    Patients with cardiac disease can develop two types of malnutrition: cardiac cachexia, which appears in chronic congestive heart failure, and malnutrition due to the complications of cardiac surgery or any other type of surgery in patients with heart disease. Early enteral nutrition should be attempted if the oral route cannot be used. When cardiac function is severely compromised, enteral nutrition is feasible, but supplementation with parenteral nutrition is sometimes required. Sustained hy...

  4. Mitochondrial Myopathy with DNA Deletions


    J Gordon Millichap


    Deletions of mitochondrial DNA (mtDNA) are reported in 19 of 56 patients with mitochondrial myopathy examined in the Department of Neurology and Neuromuscular Research Laboratory, Mayo Clinic, Rochester, MN.

  5. Adult-onset mitochondrial myopathy. (United States)

    Fernandez-Sola, J.; Casademont, J.; Grau, J. M.; Graus, F.; Cardellach, F.; Pedrol, E.; Urbano-Marquez, A.


    Mitochondrial diseases are polymorphic entities which may affect many organs and systems. Skeletal muscle involvement is frequent in the context of systemic mitochondrial disease, but adult-onset pure mitochondrial myopathy appears to be rare. We report 3 patients with progressive skeletal mitochondrial myopathy starting in adult age. In all cases, the proximal myopathy was the only clinical feature. Mitochondrial pathology was confirmed by evidence of ragged-red fibres in muscle histochemistry, an abnormal mitochondrial morphology in electron microscopy and by exclusion of other underlying diseases. No deletions of mitochondrial DNA were found. We emphasize the need to look for a mitochondrial disorder in some non-specific myopathies starting in adult life. Images Figure 1 Figure 2 PMID:1589382

  6. Sustainable Development Compromise[d] in the Planning of Metro Vancouver’s Agricultural Lands—the Jackson Farm Case

    Directory of Open Access Journals (Sweden)

    Meg Holden


    Full Text Available This research provides analysis of the case of the Jackson Farm development application, embedded within the particular dynamics of the municipal, regional, and provincial sustainability land use policy culture of the Metro Vancouver region, in Canada. Within a culture of appreciation of the increasing need for sustainability in land use policy, including the protection of agricultural lands at the provincial level through the Agricultural Land Reserve (ALR, to urban intensification and protection of the green zone at the regional scale, lies a political conflict that comes into focus in individual land use decisions, within municipalities struggling for autonomy. This case is neither driven strictly by “the politics of the highest bidder” nor by policy failure; the case of the Jackson Farm is instead a case of the challenges of implementing inter-governmental coordination and collaborative governance in a context of both significant sustainability policy and urban growth. The process can be seen to follow an ecological modernization agenda, seeking “win–win” alternatives rather than recognizing that typical compromises, over time, may tip the direction of development away from sustainability policy goals. Understanding the twists, turns, and eventual compromise reached in the case of the Jackson Farm brings to light the implications of the shift in the regional planning culture which may necessitate a less flexible, more structured prioritization of competing goals within plans and policies in order to meet sustainability goals. We highlight this, and present an alternative implementation process within the existing policy regime with potential to aid the specific goal of agricultural land protection.

  7. Molecular Basis of Cardiac Myxomas

    Directory of Open Access Journals (Sweden)

    Pooja Singhal


    Full Text Available Cardiac tumors are rare, and of these, primary cardiac tumors are even rarer. Metastatic cardiac tumors are about 100 times more common than the primary tumors. About 90% of primary cardiac tumors are benign, and of these the most common are cardiac myxomas. Approximately 12% of primary cardiac tumors are completely asymptomatic while others present with one or more signs and symptoms of the classical triad of hemodynamic changes due to intracardiac obstruction, embolism and nonspecific constitutional symptoms. Echocardiography is highly sensitive and specific in detecting cardiac tumors. Other helpful investigations are chest X-rays, magnetic resonance imaging and computerized tomography scan. Surgical excision is the treatment of choice for primary cardiac tumors and is usually associated with a good prognosis. This review article will focus on the general features of benign cardiac tumors with an emphasis on cardiac myxomas and their molecular basis.

  8. Mitochondrial calcium uptake. (United States)

    Williams, George S B; Boyman, Liron; Chikando, Aristide C; Khairallah, Ramzi J; Lederer, W J


    Calcium (Ca(2+)) uptake into the mitochondrial matrix is critically important to cellular function. As a regulator of matrix Ca(2+) levels, this flux influences energy production and can initiate cell death. If large, this flux could potentially alter intracellular Ca(2+) ([Ca(2+)]i) signals. Despite years of study, fundamental disagreements on the extent and speed of mitochondrial Ca(2+) uptake still exist. Here, we review and quantitatively analyze mitochondrial Ca(2+) uptake fluxes from different tissues and interpret the results with respect to the recently proposed mitochondrial Ca(2+) uniporter (MCU) candidate. This quantitative analysis yields four clear results: (i) under physiological conditions, Ca(2+) influx into the mitochondria via the MCU is small relative to other cytosolic Ca(2+) extrusion pathways; (ii) single MCU conductance is ∼6-7 pS (105 mM [Ca(2+)]), and MCU flux appears to be modulated by [Ca(2+)]i, suggesting Ca(2+) regulation of MCU open probability (P(O)); (iii) in the heart, two features are clear: the number of MCU channels per mitochondrion can be calculated, and MCU probability is low under normal conditions; and (iv) in skeletal muscle and liver cells, uptake per mitochondrion varies in magnitude but total uptake per cell still appears to be modest. Based on our analysis of available quantitative data, we conclude that although Ca(2+) critically regulates mitochondrial function, the mitochondria do not act as a significant dynamic buffer of cytosolic Ca(2+) under physiological conditions. Nevertheless, with prolonged (superphysiological) elevations of [Ca(2+)]i, mitochondrial Ca(2+) uptake can increase 10- to 1,000-fold and begin to shape [Ca(2+)]i dynamics.

  9. Cardiac Tumors; Tumeurs cardiaques

    Energy Technology Data Exchange (ETDEWEB)

    Laissy, J.P.; Fernandez, P. [Centre Hospitalier Universitaire Bichat Claude Bernard, Service d' Imagerie, 76 - Rouen (France); Mousseaux, E. [Hopital Europeen Georges Pompidou (HEGP), Service de Radiologie Cardio Vasculaire et Interventionnelle, 75 - Paris (France); Dacher, J.N. [Centre Hospitalier Universitaire Charles Nicolle, 75 - Rouen (France); Crochet, D. [Centre Hospitalier Universitaire, Hopital Laennec, Centre Hemodynamique, Radiologie Thoracique et Vasculaire, 44 - Nantes (France)


    Metastases are the most frequent tumors of the heart even though they seldom are recognized. Most primary cardiac tumors are benign. The main role of imaging is to differentiate a cardiac tumor from thrombus and rare pseudo-tumors: tuberculoma, hydatid cyst. Echocardiography is the fist line imaging technique to detect cardiac tumors, but CT and MRl arc useful for further characterization and differential diagnosis. Myxoma of the left atrium is the most frequent benign cardiac tumor. It usually is pedunculated and sometimes calcified. Sarcoma is the most frequent primary malignant tumor and usually presents as a sessile infiltrative tumor. Lymphoma and metastases are usually recognized by the presence of known tumor elsewhere of by characteristic direct contiguous involvement. Diagnosing primary and secondary pericardial tumors often is difficult. Imaging is valuable for diagnosis, characterization, pre-surgical evaluation and follow-up. (author)

  10. Socially differentiated cardiac rehabilitation

    DEFF Research Database (Denmark)

    Meillier, Lucette Kirsten; Nielsen, Kirsten Melgaard; Larsen, Finn Breinholt;


    to a standard rehabilitation programme (SRP). If patients were identified as socially vulnerable, they were offered an extended version of the rehabilitation programme (ERP). Excluded patients were offered home visits by a cardiac nurse. Concordance principles were used in the individualised programme elements......%. Patients were equally distributed to the SRP and the ERP. No inequality was found in attendance and adherence among referred patients. Conclusions: It seems possible to overcome unequal referral, attendance, and adherence in cardiac rehabilitation by organisation of systematic screening and social......Aim: The comprehensive cardiac rehabilitation (CR) programme after myocardial infarction (MI) improves quality of life and results in reduced cardiac mortality and recurrence of MI. Hospitals worldwide face problems with low participation rates in rehabilitation programmes. Inequality...

  11. Mitochondrial aldehyde dehydrogenase (ALDH2 protects against streptozotocin-induced diabetic cardiomyopathy: role of GSK3β and mitochondrial function

    Directory of Open Access Journals (Sweden)

    Zhang Yingmei


    acted against diabetes-induced cardiac contractile and intracellular Ca2+ dysregulation, possibly through regulation of apoptosis, glycogen synthase kinase-3β activation and mitochondrial function independent of the global metabolic profile.

  12. Cardiac arrest - cardiopulmonary resuscitation

    Institute of Scientific and Technical Information of China (English)

    Basri Lenjani; Besnik Elshani; Nehat Baftiu; Kelmend Pallaska; Kadir Hyseni; Njazi Gashi; Nexhbedin Karemani; Ilaz Bunjaku; Taxhidin Zaimi; Arianit Jakupi


    Objective:To investigate application of cardiopulmonary resuscitation(CPR) measures within the golden minutes inEurope.Methods:The material was taken from theUniversityClinical Center ofKosovo -EmergencyCentre inPristina, during the two(2) year period(2010-2011).The collected date belong to the patients with cardiac arrest have been recorded in the patients' log book protocol at the emergency clinic.Results:During the2010 to2011 in the emergency center of theCUCK inPristina have been treated a total of269 patients with cardiac arrest, of whom159 or59.1% have been treated in2010, and110 patients or40.9% in2011.Of the269 patients treated in the emergency centre,93 or34.6% have exited lethally in the emergency centre, and176 or 65.4% have been transferred to other clinics.In the total number of patients with cardiac arrest, males have dominated with186 cases, or69.1%.The average age of patients included in the survey was56.7 year oldSD±16.0 years.Of the269 patients with cardiac arrest, defibrillation has been applied for93 or34.6% of patients.In the outpatient settings defibrillation has been applied for3 or3.2% of patients.Patients were defibrillated with application of one to four shocks. Of27 cases with who have survived cardiac arrest, none of them have suffered cardiac arrest at home,3 or11.1% of them have suffered cardiac arrest on the street, and24 or88.9% of them have suffered cardiac arrest in the hospital.5 out of27 patients survived have ended with neurological impairment.Cardiac arrest cases were present during all days of the week, but frequently most reported cases have been onMonday with32.0% of cases, and onFriday with24.5% of cases. Conclusions:All survivors from cardiac arrest have received appropriate medical assistance within10 min from attack, which implies that if cardiac arrest occurs near an institution health care(with an opportunity to provide the emergent health care) the rate of survival is higher.

  13. Mitochondrial fusion dynamics is robust in the heart and depends on calcium oscillations and contractile activity. (United States)

    Eisner, Verónica; Cupo, Ryan R; Gao, Erhe; Csordás, György; Slovinsky, William S; Paillard, Melanie; Cheng, Lan; Ibetti, Jessica; Chen, S R Wayne; Chuprun, J Kurt; Hoek, Jan B; Koch, Walter J; Hajnóczky, György


    Mitochondrial fusion is thought to be important for supporting cardiac contractility, but is hardly detectable in cultured cardiomyocytes and is difficult to directly evaluate in the heart. We overcame this obstacle through in vivo adenoviral transduction with matrix-targeted photoactivatable GFP and confocal microscopy. Imaging in whole rat hearts indicated mitochondrial network formation and fusion activity in ventricular cardiomyocytes. Promptly after isolation, cardiomyocytes showed extensive mitochondrial connectivity and fusion, which decayed in culture (at 24-48 h). Fusion manifested both as rapid content mixing events between adjacent organelles and slower events between both neighboring and distant mitochondria. Loss of fusion in culture likely results from the decline in calcium oscillations/contractile activity and mitofusin 1 (Mfn1), because (i) verapamil suppressed both contraction and mitochondrial fusion, (ii) after spontaneous contraction or short-term field stimulation fusion activity increased in cardiomyocytes, and (iii) ryanodine receptor-2-mediated calcium oscillations increased fusion activity in HEK293 cells and complementing changes occurred in Mfn1. Weakened cardiac contractility in vivo in alcoholic animals is also associated with depressed mitochondrial fusion. Thus, attenuated mitochondrial fusion might contribute to the pathogenesis of cardiomyopathy.

  14. Cardiac imaging in adults

    Energy Technology Data Exchange (ETDEWEB)

    Jaffe, C.C.


    This book approaches adult cardiac disease from the correlative imaging perspective. It includes chest X-rays and angiographs, 2-dimensional echocardiograms with explanatory diagrams for clarity, plus details on digital radiology, nuclear medicine techniques, CT and MRI. It also covers the normal heart, valvular heart disease, myocardial disease, pericardial disease, bacterial endocarditis, aortic aneurysm, cardiac tumors, and congenital heart disease of the adult. It points out those aspects where one imaging technique has significant superiority.

  15. Port Access Cardiac Surgery. (United States)

    Viganó, Mario; Minzioni, Gaetano; Spreafico, Patrizio; Rinaldi, Mauro; Pasquino, Stefano; Ceriana, Piero; Locatelli, Alessandro


    The port-access technique for cardiac surgery was recently developed at Stanford University in California as a less invasive method to perform some cardiac operations. The port-access system has been described in detail elsewhere. It is based on femoral arterial and venous access for cardiopulmonary bypass (CPB) and on the adoption of a specially designed triple-lumen catheter described originally by Peters, and subsequently modified and developed in the definitive configuration called the endoaortic clamp.

  16. Awareness in cardiac anesthesia.

    LENUS (Irish Health Repository)

    Serfontein, Leon


    Cardiac surgery represents a sub-group of patients at significantly increased risk of intraoperative awareness. Relatively few recent publications have targeted the topic of awareness in this group. The aim of this review is to identify areas of awareness research that may equally be extrapolated to cardiac anesthesia in the attempt to increase understanding of the nature and significance of this scenario and how to reduce it.

  17. Post cardiac injury syndrome

    DEFF Research Database (Denmark)

    Nielsen, S L; Nielsen, F E


    The post-pericardiotomy syndrome is a symptom complex which is similar in many respects to the post-myocardial infarction syndrome and these are summarized under the diagnosis of the Post Cardiac Injury Syndrome (PCIS). This condition, which is observed most frequently after open heart surgery, i...... on the coronary vessels, with cardiac tamponade and chronic pericardial exudate. In the lighter cases, PCIS may be treated with NSAID and, in the more severe cases, with systemic glucocorticoid which has a prompt effect....

  18. Autonomic cardiac innervation


    Hasan, Wohaib


    Autonomic cardiac neurons have a common origin in the neural crest but undergo distinct developmental differentiation as they mature toward their adult phenotype. Progenitor cells respond to repulsive cues during migration, followed by differentiation cues from paracrine sources that promote neurochemistry and differentiation. When autonomic axons start to innervate cardiac tissue, neurotrophic factors from vascular tissue are essential for maintenance of neurons before they reach their targe...

  19. Infected cardiac hydatid cyst


    Ceviz, M; Becit, N; Kocak, H.


    A 24 year old woman presented with chest pain and palpitation. The presence of a semisolid mass—an echinococcal cyst or tumour—in the left ventricular apex was diagnosed by echocardiography, computed tomography, and magnetic resonance imaging. The infected cyst was seen at surgery. The cyst was removed successfully by using cardiopulmonary bypass with cross clamp.

Keywords: cardiac hydatid cyst; infected cardiac hydatid cyst

  20. Pharmacologic Effects on Mitochondrial Function (United States)

    Cohen, Bruce H.


    The vast majority of energy necessary for cellular function is produced in mitochondria. Free-radical production and apoptosis are other critical mitochondrial functions. The complex structure, electrochemical properties of the inner mitochondrial membrane (IMM), and genetic control from both mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) are…

  1. Implications of mitochondrial DNA mutations and mitochondrial dysfunction in tumorigenesis

    Institute of Scientific and Technical Information of China (English)

    Jianxin Lu; Lokendra Kumar Sharma; Yidong Bai


    Alterations in oxidative phosphorylation resulting from mitochondrial dysfunction have long been hypothesized to be involved in tumorigenesis. Mitochondria have recently been shown to play an important role in regulating both programmed cell death and cell proliferation. Furthermore, mitochondrial DNA (mtDNA) mutations have been found in various cancer cells. However, the role of these mtDNA mutations in tumorigenesis remains largely unknown. This review focuses on basic mitochondrial genetics, mtDNA mutations and consequential mitochondrial dysfunction associated with cancer. The potential molecular mechanisms, mediating the pathogenesis from mtDNA mutations and mitochondrial dysfunction to tumorigenesis are also discussed.

  2. Cardiac applications of optogenetics. (United States)

    Ambrosi, Christina M; Klimas, Aleksandra; Yu, Jinzhu; Entcheva, Emilia


    In complex multicellular systems, such as the brain or the heart, the ability to selectively perturb and observe the response of individual components at the cellular level and with millisecond resolution in time, is essential for mechanistic understanding of function. Optogenetics uses genetic encoding of light sensitivity (by the expression of microbial opsins) to provide such capabilities for manipulation, recording, and control by light with cell specificity and high spatiotemporal resolution. As an optical approach, it is inherently scalable for remote and parallel interrogation of biological function at the tissue level; with implantable miniaturized devices, the technique is uniquely suitable for in vivo tracking of function, as illustrated by numerous applications in the brain. Its expansion into the cardiac area has been slow. Here, using examples from published research and original data, we focus on optogenetics applications to cardiac electrophysiology, specifically dealing with the ability to manipulate membrane voltage by light with implications for cardiac pacing, cardioversion, cell communication, and arrhythmia research, in general. We discuss gene and cell delivery methods of inscribing light sensitivity in cardiac tissue, functionality of the light-sensitive ion channels within different types of cardiac cells, utility in probing electrical coupling between different cell types, approaches and design solutions to all-optical electrophysiology by the combination of optogenetic sensors and actuators, and specific challenges in moving towards in vivo cardiac optogenetics.

  3. A dual role for integrin-linked kinase and β1-integrin in modulating cardiac aging. (United States)

    Nishimura, Mayuko; Kumsta, Caroline; Kaushik, Gaurav; Diop, Soda B; Ding, Yun; Bisharat-Kernizan, Jumana; Catan, Hannah; Cammarato, Anthony; Ross, Robert S; Engler, Adam J; Bodmer, Rolf; Hansen, Malene; Ocorr, Karen


    Cardiac performance decreases with age, which is a major risk factor for cardiovascular disease and mortality in the aging human population, but the molecular mechanisms underlying cardiac aging are still poorly understood. Investigating the role of integrin-linked kinase (ilk) and β1-integrin (myospheroid, mys) in Drosophila, which colocalize near cardiomyocyte contacts and Z-bands, we find that reduced ilk or mys function prevents the typical changes of cardiac aging seen in wildtype, such as arrhythmias. In particular, the characteristic increase in cardiac arrhythmias with age is prevented in ilk and mys heterozygous flies with nearly identical genetic background, and they live longer, in line with previous findings in Caenorhabditis elegans for ilk and in Drosophila for mys. Consistent with these findings, we observed elevated β1-integrin protein levels in old compared with young wild-type flies, and cardiac-specific overexpression of mys in young flies causes aging-like heart dysfunction. Moreover, moderate cardiac-specific knockdown of integrin-linked kinase (ILK)/integrin pathway-associated genes also prevented the decline in cardiac performance with age. In contrast, strong cardiac knockdown of ilk or ILK-associated genes can severely compromise cardiac integrity, including cardiomyocyte adhesion and overall heart function. These data suggest that ilk/mys function is necessary for establishing and maintaining normal heart structure and function, and appropriate fine-tuning of this pathway can retard the age-dependent decline in cardiac performance and extend lifespan. Thus, ILK/integrin-associated signaling emerges as an important and conserved genetic mechanism in longevity, and as a new means to improve age-dependent cardiac performance, in addition to its vital role in maintaining cardiac integrity.

  4. Preventing Mitochondrial Fission Impairs Mitochondrial Function and Leads to Loss of Mitochondrial DNA


    Parone, Philippe A.; Sandrine Da Cruz; Daniel Tondera; Yves Mattenberger; James, Dominic I.; Pierre Maechler; François Barja; Jean-Claude Martinou


    Mitochondria form a highly dynamic tubular network, the morphology of which is regulated by frequent fission and fusion events. However, the role of mitochondrial fission in homeostasis of the organelle is still unknown. Here we report that preventing mitochondrial fission, by down-regulating expression of Drp1 in mammalian cells leads to a loss of mitochondrial DNA and a decrease of mitochondrial respiration coupled to an increase in the levels of cellular reactive oxygen species (ROS). At t...

  5. Metabolic Stress and Compromised Identity of Pancreatic Beta Cells (United States)

    Swisa, Avital; Glaser, Benjamin; Dor, Yuval


    Beta cell failure is a central feature of type 2 diabetes (T2D), but the molecular underpinnings of the process remain only partly understood. It has been suggested that beta cell failure in T2D involves massive cell death. Other studies ascribe beta cell failure to cell exhaustion, due to chronic oxidative or endoplasmic reticulum stress leading to cellular dysfunction. More recently it was proposed that beta cells in T2D may lose their differentiated identity, possibly even gaining features of other islet cell types. The loss of beta cell identity appears to be driven by glucotoxicity inhibiting the activity of key beta cell transcription factors including Pdx1, Nkx6.1, MafA and Pax6, thereby silencing beta cell genes and derepressing alternative islet cell genes. The loss of beta cell identity is at least partly reversible upon normalization of glycemia, with implications for the reversibility of T2D, although it is not known if beta cell failure reaches eventually a point of no return. In this review we discuss current evidence for metabolism-driven compromised beta cell identity, key knowledge gaps and opportunities for utility in the treatment of T2D.

  6. Compromised Rat Testicular Antioxidant Defence System by Hypothyroidism before Puberty

    Directory of Open Access Journals (Sweden)

    Dipak K. Sahoo


    Full Text Available Altered thyroid function during early stages of development is known to affect adversely testicular growth, physiology, and antioxidant defence status at adulthood. The objective of the present study is to investigate the modulation of antioxidant defence status in neonatal persistent hypothyroid rats before their sexual maturation and also to identify the specific testicular cell populations vulnerable to degeneration during neonatal hypothyroidism in immature rats. Hypothyroidism was induced in neonates by feeding the lactating mother with 0.05% 6-n-propyl-2-thiouracil (PTU through the drinking water. From the day of parturition till weaning (25 day postpartum, the pups received PTU through mother's milk (or drinking water and then directly from drinking water containing PTU for the remaining period of experimentation. On the 31st day postpartum, the animals were sacrificed for the study. An altered antioxidant defence system marked by elevated SOD, CAT, and GR activities, with decreased GPx and GST activities were observed along with increased protein carbonylation, disturbed redox status in hypothyroid immature rat testis. This compromised testicular antioxidant status might have contributed to poor growth and development by affecting the spermatogenesis and steroidogenesis in rats before puberty as indicated by reduced germ cell number, complete absence of round spermatids, decreased seminiferous tubule diameter, and decreased testosterone level.

  7. Protection characteristics of a Faraday cage compromised by lightning burnthrough.

    Energy Technology Data Exchange (ETDEWEB)

    Warne, Larry Kevin; Bystrom, Edward; Jorgenson, Roy Eberhardt; Montoya, Sandra L.; Merewether, Kimball O.; Coats, Rebecca Sue; Martinez, Leonard E.; Jojola, John M.


    A lightning flash consists of multiple, high-amplitude but short duration return strokes. Between the return strokes is a lower amplitude, continuing current which flows for longer duration. If the walls of a Faraday cage are made of thin enough metal, the continuing current can melt a hole through the metal in a process called burnthrough. A subsequent return stroke can couple energy through this newly-formed hole. This LDRD is a study of the protection provided by a Faraday cage when it has been compromised by burnthrough. We initially repeated some previous experiments and expanded on them in terms of scope and diagnostics to form a knowledge baseline of the coupling phenomena. We then used a combination of experiment, analysis and numerical modeling to study four coupling mechanisms: indirect electric field coupling, indirect magnetic field coupling, conduction through plasma and breakdown through the hole. We discovered voltages higher than those encountered in the previous set of experiments (on the order of several hundreds of volts).

  8. Daniel Deronda: George Eliot’s Victorian Compromise

    Directory of Open Access Journals (Sweden)

    Ahmed Kahky


    Full Text Available Eventually, it seems Mrs. Lewes thought of re-emigrating the surplus of Jewish denizens in England to some exotic land in the East as a measure of freeing the English people from the inconvenience they complain of, the same way she and her illegal spouse thought of sending his sons to Natal in South Africa to free themselves from the any inconvenience at home. In other words, this was the Victorian compromise of the Jewish surplus at a time of extreme chauvinism and expanding imperialism.  Thus, the ideological background of Daniel Deronda represents the confluence—and compromise—between the ideological trends of imperialism and Zionism according to which the first creates, supports, and maintains the latter for its colonialist purposes. In fact, George Eliot’s indifference to the “rights and dignities” of the native, historical, and generational inhabitants of the land of Palestine resulted in the world’s gravest crime against humanity.

  9. Towards mesoscience the principle of compromise in competition

    CERN Document Server

    Li, Jinghai


    This brief is devoted to providing a complete outline of meso-science by briefing the relevant contents from the published book and by updating evidences and concepts of meso-science. The importance of meso-science in solving various problems in energy, resource, and the environment is introduced.  The whole evolutionary development of the EMMS principle is reviewed to show how a simple idea on the customized modeling of particle clustering in gas-solid systems was developed, verified, extended, and finally generalized into the common principle of compromise in competition between dominant mechanisms for all mesoscale phenomena in science and engineering, leading to the proposition of meso-science. More importantly, updates on the concept of meso-science and perspectives are presented, along with new insights and findings from after the publication of the original book. In this way, we hope to help readers more easily familiarize themselves with meso-science, and to trigger interest and attention to this int...

  10. Auditing Litigation and Claims: Conflicts and the Compromise of Privilege

    Directory of Open Access Journals (Sweden)

    Harleen Kaur


    Full Text Available Auditing standards require an auditor to make various enquiries about liabilities in general this may entail consideration of potential litigations and claims that the audited entity may be facing. To perform this part of audit, the auditors will generally seek representation letters from lawyers of the company detailing an estimate prepared by management, confirmed by their lawyers through a representation letter, and then sent directly to the auditors. This paper reviews the implications for the auditing profession of a case that involved auditors seeking such representation letters. The case involves litigation between theWestpac Banking Corporation and 789TEN Pty Ltd. While theWestpac case confirmed the legal position of the auditor in their task of collecting evidence in order to form an opinion in Australia, it highlights a significant anomaly under the law and should place the issue of solicitor’s representation letters as audit evidence firmly on the agenda of policymakers. This issue of the compromise of legal privilege during the conduct of an audit is also not confined to Australia: other common law jurisdictions, such as the UK and the US, have also sought to clarify the position of auditors when issues of the integrity of legal privacy privilege arise.

  11. Physiologic assessment of fetal compromise: biomarkers of toxic exposure

    Energy Technology Data Exchange (ETDEWEB)

    Longo, L.D.


    Understanding the physiologic and endocrinologic basis of fetal development is a major goal of perinatal biology. During the past decade a number of technological developments have allowed more precise evaluation of the fetus in utero and diagnosis of abnormalities. Despite these methodological achievements, however, there are no specific biological markers currently available to indicate that exposure to a given xenobiotic is associated with a cellular, subcellular, or pharmacodynamic event. This paper evaluates the following issues: what are some of the unique physiologic and endocrinologic features of the fetal milieu interieur. What problems are peculiar to fetal assessment. What are some examples of validated biomarkers and their applicability. What promising biomarkers are on the horizon. How may molecular probes be of value as biological markers of fetal compromise. What are some of the major research gaps and needs, and how should research priorities be set. Some of these topics are addressed. Moreover, the more general role(s) that various diagnostic methods and biological markers can have in an understanding of the regulation of fetal growth and differentiation and the role of xenobiotics in affecting the normal course of events are discussed.

  12. Oviposition site selection in Cactoblastis cactorum (Lepidoptera): constraints and compromises. (United States)

    Robertson, H G


    Oviposition by Cactoblastis cactorum on Opuntia ficus-indica and O. aurantiaca was assessed from the positioning of egg sticks on plants in the field. The number of egg sticks laid on O. ficus-indica plants was affected by: (1) plant size; (2) moth emergence near the plant; (3) cladode condition; and (4) plant conspicuousness. These factors contributed towards the clumping of egg sticks on plants. There was no apparent oviposition preference for one of the two host plant species despite the fact that egg predation was higher and fecundity lower on O. aurantiaca. The selection of a site for oviposition on the host plants was influenced by: (1) cladode condition; (2) height above ground; and (3) shelter from wind during oviposition. Succulent cladodes were the favoured sites for oviposition. The evidence suggests that in C. cactorum, oviposition site selection is largely the net result of a compromise between oviposition behaviour selected for increasing the probability of juvenile survival and oviposition behaviour selected for increasing the probability of laying the full complement of eggs. In addition, environmental and physiological factors such as wind and wing-loading, are thought to place constraints on the range of sites available for oviposition.

  13. Melatonin mitigates mitochondrial malfunction. (United States)

    León, Josefa; Acuña-Castroviejo, Darío; Escames, Germane; Tan, Dun-Xian; Reiter, Russel J


    Melatonin, or N-acetyl-5-methoxytryptamine, is a compound derived from tryptophan that is found in all organisms from unicells to vertebrates. This indoleamine may act as a protective agent in disease conditions such as Parkinson's, Alzheimer's, aging, sepsis and other disorders including ischemia/reperfusion. In addition, melatonin has been proposed as a drug for the treatment of cancer. These disorders have in common a dysfunction of the apoptotic program. Thus, while defects which reduce apoptotic processes can exaggerate cancer, neurodegenerative disorders and ischemic conditions are made worse by enhanced apoptosis. The mechanism by which melatonin controls cell death is not entirely known. Recently, mitochondria, which are implicated in the intrinsic pathway of apoptosis, have been identified as a target for melatonin actions. It is known that melatonin scavenges oxygen and nitrogen-based reactants generated in mitochondria. This limits the loss of the intramitochondrial glutathione and lowers mitochondrial protein damage, improving electron transport chain (ETC) activity and reducing mtDNA damage. Melatonin also increases the activity of the complex I and complex IV of the ETC, thereby improving mitochondrial respiration and increasing ATP synthesis under normal and stressful conditions. These effects reflect the ability of melatonin to reduce the harmful reduction in the mitochondrial membrane potential that may trigger mitochondrial transition pore (MTP) opening and the apoptotic cascade. In addition, a reported direct action of melatonin in the control of currents through the MTP opens a new perspective in the understanding of the regulation of apoptotic cell death by the indoleamine.

  14. Mitochondrial Dysfunction in Cancer

    Directory of Open Access Journals (Sweden)

    Michelle L Boland


    Full Text Available A mechanistic understanding of how mitochondrial dysfunction contributes to cell growth and tumorigenesis is emerging beyond Warburg as an area of research that is under-explored in terms of its significance for clinical management of cancer. Work discussed in this review focuses less on the Warburg effect and more on mitochondria and how dysfunctional mitochondria modulate cell cycle, gene expression, metabolism, cell viability and other more conventional aspects of cell growth and stress responses. There is increasing evidence that key oncogenes and tumor suppressors modulate mitochondrial dynamics through important signaling pathways and that mitochondrial mass and function vary between tumors and individuals but the sigificance of these events for cancer are not fully appreciated. We explore the interplay between key molecules involved in mitochondrial fission and fusion and in apoptosis, as well as in mitophagy, biogenesis and spatial dynamics and consider how these distinct mechanisms are coordinated in response to physiological stresses such as hypoxia and nutrient deprivation. Importantly, we examine how deregulation of these processes in cancer has knockon effects for cell proliferation and growth. Scientifically, there is also scope for defining what mitochondria dysfunction is and here we address the extent to which the functional consequences of such dysfunction can be determined and exploited for cancer diagnosis and treatment.

  15. Estrogen regulation of mitochondrial bioenergetics: implications for prevention of Alzheimer's disease. (United States)

    Yao, Jia; Brinton, Roberta Diaz


    Alzheimer's disease (AD) is a neurodegenerative disease with a complex and progressive pathological phenotype characterized first by hypometabolism and impaired mitochondrial bioenergetics followed by pathological burden. Increasing evidence indicates an antecedent and potentially causal role of mitochondrial bioenergetic deficits and brain hypometabolism coupled with increased mitochondrial oxidative stress in AD pathogenesis. Compromised aerobic glycolysis pathway coupled with oxidative stress is first accompanied by a shift toward a ketogenic pathway that eventually progresses into fatty acid oxidation (FAO) pathways and leads to white matter degeneration and overproduction and mitochondrial accumulation of β-amyloid. Estrogen-induced signaling pathways converge upon the mitochondria to enhance mitochondrial function and to sustain aerobic glycolysis coupled with citric acid cycle-driven oxidative phosphorylation to potentiate ATP (Adenosine triphosphate) generation. In addition to potentiated mitochondrial bioenergetics, estrogen also enhances neural survival and health through maintenance of calcium homeostasis, promotion of antioxidant defense against free radicals, efficient cholesterol trafficking, and beta amyloid clearance. Significantly, the convergence of E2 mechanisms of action onto mitochondria is also a potential point of vulnerability when activated in diseased neurons that exacerbates degeneration through increased load on dysregulated calcium homeostasis. The "healthy cell bias of estrogen action" hypothesis examines the role that regulating mitochondrial function and bioenergetics play in promoting neural health and the mechanistic crossroads that lead to divergent outcomes following estrogen exposure. As the continuum of neurological health progresses from healthy to unhealthy, so too do the benefits of estrogen or hormone therapy.

  16. Peroxynitrite induced mitochondrial biogenesis following MnSOD knockdown in normal rat kidney (NRK cells

    Directory of Open Access Journals (Sweden)

    Akira Marine


    Full Text Available Superoxide is widely regarded as the primary reactive oxygen species (ROS which initiates downstream oxidative stress. Increased oxidative stress contributes, in part, to many disease conditions such as cancer, atherosclerosis, ischemia/reperfusion, diabetes, aging, and neurodegeneration. Manganese superoxide dismutase (MnSOD catalyzes the dismutation of superoxide into hydrogen peroxide which can then be further detoxified by other antioxidant enzymes. MnSOD is critical in maintaining the normal function of mitochondria, thus its inactivation is thought to lead to compromised mitochondria. Previously, our laboratory observed increased mitochondrial biogenesis in a novel kidney-specific MnSOD knockout mouse. The current study used transient siRNA mediated MnSOD knockdown of normal rat kidney (NRK cells as the in vitro model, and confirmed functional mitochondrial biogenesis evidenced by increased PGC1α expression, mitochondrial DNA copy numbers and integrity, electron transport chain protein CORE II, mitochondrial mass, oxygen consumption rate, and overall ATP production. Further mechanistic studies using mitoquinone (MitoQ, a mitochondria-targeted antioxidant and L-NAME, a nitric oxide synthase (NOS inhibitor demonstrated that peroxynitrite (at low micromolar levels induced mitochondrial biogenesis. These findings provide the first evidence that low levels of peroxynitrite can initiate a protective signaling cascade involving mitochondrial biogenesis which may help to restore mitochondrial function following transient MnSOD inactivation.

  17. Mitochondrial dysfunction accounts for the stochastic heterogeneity in telomere-dependent senescence.

    Directory of Open Access Journals (Sweden)

    João F Passos


    Full Text Available Aging is an inherently stochastic process, and its hallmark is heterogeneity between organisms, cell types, and clonal populations, even in identical environments. The replicative lifespan of primary human cells is telomere dependent; however, its heterogeneity is not understood. We show that mitochondrial superoxide production increases with replicative age in human fibroblasts despite an adaptive UCP-2-dependent mitochondrial uncoupling. This mitochondrial dysfunction is accompanied by compromised [Ca(2+]i homeostasis and other indicators of a retrograde response in senescent cells. Replicative senescence of human fibroblasts is delayed by mild mitochondrial uncoupling. Uncoupling reduces mitochondrial superoxide generation, slows down telomere shortening, and delays formation of telomeric gamma-H2A.X foci. This indicates mitochondrial production of reactive oxygen species (ROS as one of the causes of replicative senescence. By sorting early senescent (SES cells from young proliferating fibroblast cultures, we show that SES cells have higher ROS levels, dysfunctional mitochondria, shorter telomeres, and telomeric gamma-H2A.X foci. We propose that mitochondrial ROS is a major determinant of telomere-dependent senescence at the single-cell level that is responsible for cell-to-cell variation in replicative lifespan.

  18. Effect of fast-track cardiac anesthesia on myocardial oxidative damage, inflammation and nerve related peptides of patients undergoing cardiac operation

    Institute of Scientific and Technical Information of China (English)

    Xing-Tao Cai; Zhong-Jun Zhang; Wen-Bo Diao


    Objective:To study the effect of fast-track cardiac anesthesia on myocardial oxidative damage, inflammation and nerve related peptides of patients undergoing cardiac operation.Methods:Sixty patients with rheumatic heart disease undergoing heart valve surgery were randomly divided into the fast track group (n=30) and conventional group (n=30). Then myocardial injury indicators, mitochondrial oxidative stress indicators, inflammation indicators and nerve-related peptides of both groups were analyzed.Results: cTnI contents at T2-T4 points in time of both groups showed an increasing trend and the increasing trend of fast track group was weaker than that of conventional group; SOD contents as well as mitochondrial tristate respiratory function, respiratory control ratios and phosphorus oxygen ratios in myocardial tissue of fast track group were higher than those of conventional group, and MDA contents was lower than those of conventional group; plasma TNF-α, IL-6, IL-8, NSE, S100β and Aβcontents of fast track group were lower than those of conventional group.Conclusions:Fast-track cardiac anesthesia can protect myocardial cells, reduce mitochondrial oxidative stress, relieve inflammation and improve nerve function; it is an ideal anesthesia method for cardiac operation.

  19. Inflammation and cardiac dysfunction during sepsis, muscular dystrophy, and myocarditis

    Directory of Open Access Journals (Sweden)

    Ying Li


    Full Text Available Inflammation plays an important role in cardiac dysfunction under different situations. Acute systemic inflammation occurring in patients with severe burns, trauma, and inflammatory diseases causes cardiac dysfunction, which is one of the leading causes of mortality in these patients. Acute sepsis decreases cardiac contractility and impairs myocardial compliance. Chronic inflammation such as that occurring in Duchenne muscular dystropshy and myocarditis may cause adverse cardiac remodeling including myocyte hypertrophy and death, fibrosis, and altered myocyte function. However, the underlying cellular and molecular mechanisms for inflammatory cardiomyopathy are still controversial probably due to multiple factors involved. Potential mechanisms include the change in circulating blood volume; a direct inhibition of myocyte contractility by cytokines (tumor necrosis factor (TNF-a, interleukin (IL-1b; abnormal nitric oxide and reactive oxygen species (ROS signaling; mitochondrial dysfunction; abnormal excitation-contraction coupling; and reduced calcium sensitivity at the myofibrillar level and blunted b-adrenergic signaling. This review will summarize recent advances in diagnostic technology, mechanisms, and potential therapeutic strategies for inflammation-induced cardiac dysfunction.

  20. [Psychosomatic aspects of cardiac arrhythmias]. (United States)

    Siepmann, Martin; Kirch, Wilhelm


    Emotional stress facilitates the occurrence of cardiac arrhythmias including sudden cardiac death. The prevalence of anxiety and depression is increased in cardiac patients as compared to the normal population. The risk of cardiovascular mortality is enhanced in patients suffering from depression. Comorbid anxiety disorders worsen the course of cardiac arrhythmias. Disturbance of neurocardiac regulation with predominance of the sympathetic tone is hypothesized to be causative for this. The emotional reaction to cardiac arrhythmias is differing to a large extent between individuals. Emotional stress may result from coping with treatment of cardiac arrhythmias. Emotional stress and cardiac arrhythmias may influence each other in the sense of a vicious circle. Somatoform cardiac arrhythmias are predominantly of psychogenic origin. Instrumental measures and frequent contacts between physicians and patients may facilitate disease chronification. The present review is dealing with the multifaceted relationships between cardiac arrhythmias and emotional stress. The underlying mechanisms and corresponding treatment modalities are discussed.

  1. Cystein cathepsin and Hsp90 activities determine the balance between apoptotic and necrotic cell death pathways in caspase-compromised U937 cells. (United States)

    Imre, Gergely; Dunai, Zsuzsanna; Petak, Istvan; Mihalik, Rudolf


    Caspase-inhibited cells induced to die may exhibit the traits of either apoptosis or necrosis or both, simultaneously. However, mechanisms regulating the commitment to these distinct forms of cell death are barely identified. We found that staurosporine induced both apoptotic and necrotic traits in U937 cells exposed to the caspase inhibitor benzyloxycarbonyl-Val-Ala-DL-Asp(OMe)-fluoromethylketone. Morphology and flow cytometry revealed that individual cells exhibited either apoptotic or necrotic traits, but not the mixed phenotype. Inhibition of cathepsin activity by benzyloxycarbonyl-Phe-Ala-fluoromethylketone rendered caspase-compromised cells resistant to staurosporine-induced apoptosis, but switched the cell death form to necrosis. Inhibition of heat shock protein 90 kDa (Hsp90) chaperon activity by geldanamycin conferred resistance to necrosis in caspase-compromised cells but switched the cell death form to apoptosis. Combination of benzyloxycarbonyl-Phe-Ala-fluoromethylketone and geldanamycin halted the onset of both forms of cell death by saving mitochondrial trans-membrane potential and preventing acidic volume (lysosomes) loss. These effects of benzyloxycarbonyl-Phe-Ala-fluoromethylketone and/or geldanamycin on cell death were restricted to caspase-inhibited cells exposed to staurosporine but influenced neither only the staurosporine-provoked apoptosis nor hydrogen peroxide (H2O2)-generated necrosis. Our results demonstrate that the staurosporine-induced death pathway bifurcates in caspase-compromised cells and commitment to apoptotic or necrotic phenotypes depends on cathepsin protease or Hsp90 chaperon activities.

  2. Cardiac energy metabolic alterations in pressure overload–induced left and right heart failure (2013 Grover Conference Series)


    Sankaralingam, Sowndramalingam; Gary D Lopaschuk


    Pressure overload of the heart, such as seen with pulmonary hypertension and/or systemic hypertension, can result in cardiac hypertrophy and the eventual development of heart failure. The development of hypertrophy and heart failure is accompanied by numerous molecular changes in the heart, including alterations in cardiac energy metabolism. Under normal conditions, the high energy (adenosine triphosphate [ATP]) demands of the heart are primarily provided by the mitochondrial oxidation of fat...

  3. Protective effects of piperine against copper-ascorbate induced toxic injury to goat cardiac mitochondria in vitro. (United States)

    Dutta, Mousumi; Ghosh, Arnab Kumar; Mishra, Prachi; Jain, Garima; Rangari, Vinod; Chattopadhyay, Aindrila; Das, Tridib; Bhowmick, Debajit; Bandyopadhyay, Debasish


    Piperine, the main alkaloid of black pepper, Piper nigrum Linn., is an important Indian spice used in traditional food and medicine in India. In the present study, we investigated the antioxidant activities of piperine against copper-ascorbate induced toxic injury to mitochondria obtained from a goat heart, in vitro. Incubation of isolated cardiac mitochondria with copper-ascorbate resulted in elevated levels of lipid peroxidation and protein carbonylation of the mitochondrial membrane, a reduced level of mitochondrial GSH and altered status of antioxidant enzymes as well as decreased activities of pyruvate dehydrogenase and the Kreb's cycle enzymes, altered mitochondrial morphology, mitochondrial swelling, di-tyrosine level and mitochondrial DNA damage. All these changes were found to be ameliorated when the cardiac mitochondria were co-incubated with copper-ascorbate and piperine, in vitro. Piperine, in our in vitro experiments, was found to scavenge hydrogen peroxide, superoxide anion free radicals, hydroxyl radicals and DPPH radicals, in a chemically defined system, indicating that this compound may provide protection to cardiac mitochondria against copper-ascorbate induced toxic injury through its antioxidant activities. The results of this study suggest that piperine may be considered as a future therapeutic antioxidant and may be used singly or as a co-therapeutic in the treatment of diseases associated with mitochondrial oxidative stress.

  4. Protective and biogenesis effects of sodium hydrosulfide on brain mitochondria after cardiac arrest and resuscitation. (United States)

    Pan, Hao; Xie, Xuemeng; Chen, Di; Zhang, Jincheng; Zhou, Yaguang; Yang, Guangtian


    Mitochondrial dysfunction plays a critical role in brain injury after cardiac arrest and cardiopulmonary resuscitation (CPR). Recent studies demonstrated that hydrogen sulfide (H2S) donor compounds preserve mitochondrial morphology and function during ischemia-reperfusion injury. In this study, we sought to explore the effects of sodium hydrosulfide (NaHS) on brain mitochondria 24h after cardiac arrest and resuscitation. Male Sprague-Dawley rats were subjected to 6min cardiac arrest and then resuscitated successfully. Rats received NaHS (0.5mg/kg) or vehicle (0.9% NaCl, 1.67ml/kg) 1min before the start of CPR intravenously, followed by a continuous infusion of NaHS (1.5mg/kg/h) or vehicle (5ml/kg/h) for 3h. Neurological deficit was evaluated 24h after resuscitation and then cortex was collected for assessments. As a result, we found that rats treated with NaHS revealed an improved neurological outcome and cortex mitochondrial morphology 24h after resuscitation. We also observed that NaHS therapy reduced intracellular reactive oxygen species generation and calcium overload, inhibited mitochondrial permeability transition pores, preserved mitochondrial membrane potential, elevated ATP level and ameliorated the cytochrome c abnormal distribution. Further studies indicated that NaHS administration increased mitochondrial biogenesis in cortex at the same time. Our findings suggested that administration of NaHS 1min prior CPR and followed by a continuous infusion ameliorated neurological dysfunction 24h after resuscitation, possibly through mitochondria preservation as well as by promoting mitochondrial biogenesis.

  5. Cardiac radiology: centenary review. (United States)

    de Roos, Albert; Higgins, Charles B


    During the past century, cardiac imaging technologies have revolutionized the diagnosis and treatment of acquired and congenital heart disease. Many important contributions to the field of cardiac imaging were initially reported in Radiology. The field developed from the early stages of cardiac imaging, including the use of coronary x-ray angiography and roentgen kymography, to nowadays the widely used echocardiographic, nuclear medicine, cardiac computed tomographic (CT), and magnetic resonance (MR) applications. It is surprising how many of these techniques were not recognized for their potential during their early inception. Some techniques were described in the literature but required many years to enter the clinical arena and presently continue to expand in terms of clinical application. The application of various CT and MR contrast agents for the diagnosis of myocardial ischemia is a case in point, as the utility of contrast agents continues to expand the noninvasive characterization of myocardium. The history of cardiac imaging has included a continuous process of advances in our understanding of the anatomy and physiology of the cardiovascular system, along with advances in imaging technology that continue to the present day.

  6. Double-valve Libman-Sacks endocarditis causing ventricular fibrillation cardiac arrest. (United States)

    Tanawuttiwat, Tanyanan; Dia, Muhyaldeen; Hanif, Tabassum; Mihailescu, Mihaela


    Libman-Sacks endocarditis is a well-known and rather common cardiac manifestation of systemic lupus erythematosus. Transesophageal and transthoracic echocardiography are the definitive imaging methods used to evaluate cardiac valvular involvement in this disease. Valvular masses (vegetations) and valvular thickening are 2 common morphologic echocardiographic patterns. Libman-Sacks lesions are typically characterized by single-valve involvement and their small size of 1 to 4 mm.Herein, we present the unusual case of a 22-year-old woman with newly diagnosed systemic lupus erythematosus who had large, sterile vegetations of Libman-Sacks endocarditis that involved the mitral and aortic valves. This compromised coronary blood flow and resulted in ventricular fibrillation cardiac arrest. The vegetations were surgically excised, and the patient's cardiac function recovered. We discuss the treatment of the patient and that of Libman-Sacks endocarditis.

  7. The muscle-mechanical compromise framework: Implications for the scaling of gait and posture

    Directory of Open Access Journals (Sweden)

    Usherwood James Richard (Jim


    Full Text Available Many aspects of animal and human gait and posture cannot be predicted from purely mechanical work minimization or entirely based on optimizing muscle efficiency. Here, the Muscle-Mechanical Compromise Framework is introduced as a conceptual paradigm for considering the interactions and compromises between these two objectives. Current assumptions in implementing the Framework are presented. Implications of the compromise are discussed and related to the scaling of running mechanics and animal posture.

  8. Preventing mitochondrial fission impairs mitochondrial function and leads to loss of mitochondrial DNA.

    Directory of Open Access Journals (Sweden)

    Philippe A Parone

    Full Text Available Mitochondria form a highly dynamic tubular network, the morphology of which is regulated by frequent fission and fusion events. However, the role of mitochondrial fission in homeostasis of the organelle is still unknown. Here we report that preventing mitochondrial fission, by down-regulating expression of Drp1 in mammalian cells leads to a loss of mitochondrial DNA and a decrease of mitochondrial respiration coupled to an increase in the levels of cellular reactive oxygen species (ROS. At the cellular level, mitochondrial dysfunction resulting from the lack of fission leads to a drop in the levels of cellular ATP, an inhibition of cell proliferation and an increase in autophagy. In conclusion, we propose that mitochondrial fission is required for preservation of mitochondrial function and thereby for maintenance of cellular homeostasis.

  9. Mutations in calmodulin cause ventricular tachycardia and sudden cardiac death

    DEFF Research Database (Denmark)

    Nyegaard, Mette; Overgaard, Michael Toft; Søndergaard, Mads


    a substantial part of sudden cardiac deaths in young individuals. Mutations in RYR2, encoding the cardiac sarcoplasmic calcium channel, have been identified as causative in approximately half of all dominantly inherited CPVT cases. Applying a genome-wide linkage analysis in a large Swedish family with a severe...... dominantly inherited form of CPVT-like arrhythmias, we mapped the disease locus to chromosome 14q31-32. Sequencing CALM1 encoding calmodulin revealed a heterozygous missense mutation (c.161A>T [p.Asn53Ile]) segregating with the disease. A second, de novo, missense mutation (c.293A>G [p.Asn97Ser......]) was subsequently identified in an individual of Iraqi origin; this individual was diagnosed with CPVT from a screening of 61 arrhythmia samples with no identified RYR2 mutations. Both CALM1 substitutions demonstrated compromised calcium binding, and p.Asn97Ser displayed an aberrant interaction with the RYR2...

  10. Cardiac tamponade as initial presentation in systemic lupus erythematosus. (United States)

    Jawaid, Ambreen; Almas, Aysha


    Systemic Lupus Erythematosus (SLE) is one of the many diseases known as 'the great imitators' because it can have diverse presentations and so is misunderstood for other illnesses. This case illustrates a 19 years old girl with SLE who presented as cardiac tamponade which is a rare feature of lupus pericarditis requiring medical and surgical treatment. Even after pericardiocentesis and steroid therapy there was a re-accumulation of the pericardial fluid resulting in cardiac tamponade which led to pericardial window formation. This case draws attention to the need to consider the diagnosis of tamponade in patients with connective tissue disease and dyspnea or hemodynamic compromise. It also outlines the treatment options available so that surgical referral, if needed, can be done timely for this rare but life threatening manifestation of SLE.

  11. The acute phase of experimental cardiogenic shock is counteracted by microcirculatory and mitochondrial adaptations. (United States)

    Stenberg, Thor Allan; Kildal, Anders Benjamin; Sanden, Espen; How, Ole-Jakob; Hagve, Martin; Ytrehus, Kirsti; Larsen, Terje S; Myrmel, Truls


    The mechanisms contributing to multiorgan dysfunction during cardiogenic shock are poorly understood. Our goal was to characterize the microcirculatory and mitochondrial responses following ≥ 10 hours of severe left ventricular failure and cardiogenic shock. We employed a closed-chest porcine model of cardiogenic shock induced by left coronary microembolization (n = 12) and a time-matched control group (n = 6). Hemodynamics and metabolism were measured hourly by intravascular pressure catheters, thermodilution, arterial and organ specific blood gases. Echocardiography and assessment of the sublingual microcirculation by sidestream darkfield imaging were performed at baseline, 2 ± 1 and 13 ± 3 (mean ± SD) hours after coronary microembolization. Upon hemodynamic decompensation, cardiac, renal and hepatic mitochondria were isolated and evaluated by high-resolution respirometry. Low cardiac output, hypotension, oliguria and severe reductions in mixed-venous and hepatic O2 saturations were evident in cardiogenic shock. The sublingual total and perfused vessel densities were fully preserved throughout the experiments. Cardiac mitochondrial respiration was unaltered, whereas state 2, 3 and 4 respiration of renal and hepatic mitochondria were increased in cardiogenic shock. Mitochondrial viability (RCR; state 3/state 4) and efficiency (ADP/O ratio) were unaffected. Our study demonstrates that the microcirculation is preserved in a porcine model of untreated cardiogenic shock despite vital organ hypoperfusion. Renal and hepatic mitochondrial respiration is upregulated, possibly through demand-related adaptations, and the endogenous shock response is thus compensatory and protective, even after several hours of global hypoperfusion.

  12. Pediatric cardiac postoperative care

    Directory of Open Access Journals (Sweden)

    Auler Jr. José Otávio Costa


    Full Text Available The Heart Institute of the University of São Paulo, Medical School is a referral center for the treatment of congenital heart diseases of neonates and infants. In the recent years, the excellent surgical results obtained in our institution may be in part due to modern anesthetic care and to postoperative care based on well-structured protocols. The purpose of this article is to review unique aspects of neonate cardiovascular physiology, the impact of extracorporeal circulation on postoperative evolution, and the prescription for pharmacological support of acute cardiac dysfunction based on our cardiac unit protocols. The main causes of low cardiac output after surgical correction of heart congenital disease are reviewed, and methods of treatment and support are proposed as derived from the relevant literature and our protocols.

  13. Comprehensive cardiac rehabilitation

    DEFF Research Database (Denmark)

    Kruse, Marie; Hochstrasser, Stefan; Zwisler, Ann-Dorthe O;


    OBJECTIVES: The costs of comprehensive cardiac rehabilitation are established and compared to the corresponding costs of usual care. The effect on health-related quality of life is analyzed. METHODS: An unprecedented and very detailed cost assessment was carried out, as no guidelines existed...... for the situation at hand. Due to challenging circumstances, the cost assessment turned out to be ex-post and top-down. RESULTS: Cost per treatment sequence is estimated to be approximately euro 976, whereas the incremental cost (compared with usual care) is approximately euro 682. The cost estimate is uncertain...... and may be as high as euro 1.877. CONCLUSIONS: Comprehensive cardiac rehabilitation is more costly than usual care, and the higher costs are not outweighed by a quality of life gain. Comprehensive cardiac rehabilitation is, therefore, not cost-effective....

  14. Toothache of cardiac origin. (United States)

    Kreiner, M; Okeson, J P


    Pain referred to the orofacial structures can sometimes be a diagnostic challenge for the clinician. In some instances, a patient may complain of tooth pain that is completely unrelated to any dental source. This poses a diagnostic and therapeutic problem for the dentist. Cardiac pain most commonly radiates to the left arm, shoulder, neck, and face. In rare instances, angina pectoris may present as dental pain. When this occurs, an improper diagnosis frequently leads to unnecessary dental treatment or, more significantly, a delay of proper treatment. This delay may result in the patient experiencing an acute myocardial infarction. It is the dentist's responsibility to establish a proper diagnosis so that the treatment will be directed toward the source of pain and not to the site of pain. This article reviews the literature concerning referred pain of cardiac origin and presents a case report of toothache of cardiac origin.

  15. The cardiac anxiety questionnaire: cross-validation among cardiac inpatients

    NARCIS (Netherlands)

    Beek, M.H. van; Oude Voshaar, R.C.; Deelen, F.M. van; Balkom, A.J. van; Pop, G.A.; Speckens, A.E.


    OBJECTIVE: General anxiety symptoms are common in patients with cardiac disease and considered to have an adverse effect on cardiac prognosis. The role of specific cardiac anxiety, however, is still unknown. The aim of this study is to examine the factor structure, reliability, and validity of the D


    NARCIS (Netherlands)

    van Beek, M. H. C. T.; Voshaar, R. C. Oude; van Deelen, F. M.; van Balkom, A. J. L. M.; Pop, G.; Speckens, A. E. M.


    Objective: General anxiety symptoms are common in patients with cardiac disease and considered to have an adverse effect on cardiac prognosis. The role of specific cardiac anxiety, however, is still unknown. The aim of this study is to examine the factor structure, reliability, and validity of the D

  17. Mitochondrial nucleoid interacting proteins support mitochondrial protein synthesis. (United States)

    He, J; Cooper, H M; Reyes, A; Di Re, M; Sembongi, H; Litwin, T R; Gao, J; Neuman, K C; Fearnley, I M; Spinazzola, A; Walker, J E; Holt, I J


    Mitochondrial ribosomes and translation factors co-purify with mitochondrial nucleoids of human cells, based on affinity protein purification of tagged mitochondrial DNA binding proteins. Among the most frequently identified proteins were ATAD3 and prohibitin, which have been identified previously as nucleoid components, using a variety of methods. Both proteins are demonstrated to be required for mitochondrial protein synthesis in human cultured cells, and the major binding partner of ATAD3 is the mitochondrial ribosome. Altered ATAD3 expression also perturbs mtDNA maintenance and replication. These findings suggest an intimate association between nucleoids and the machinery of protein synthesis in mitochondria. ATAD3 and prohibitin are tightly associated with the mitochondrial membranes and so we propose that they support nucleic acid complexes at the inner membrane of the mitochondrion.


    Directory of Open Access Journals (Sweden)

    P. Ayatollahi


    Full Text Available Mitochondrial neurogastrointestinal encephalo-myopathy (MNGIE is a rare autosomal recessive disease caused by thymidine phosphorylase (TP gene mutation. Here we report a patient with MNGIE in whom sensorimotor polyneuropathy was the first presenting symptom and had a fluctuating course. This 26-year-old female patient developed acute-onset demyelinating polyneuropathy from the age of 6 with two relapses later on. In addition, she had gastrointestinal symptoms (diarrhea, recurrent abdominal pain, progressive weight loss and ophthalmoparesis. Brain magnetic resonance imaging showed white matter abnormalities, and muscle biopsy showed ragged red fibers. This constellation of clinical and laboratory findings raised the diagnosis of mitochondrial neurogastrointestinal encephalomyopathy (MNGIE. This report highlights the uncommon clinical characteristics of this rare disease.

  19. Impact of the renin-angiotensin system on cardiac energy metabolism in heart failure. (United States)

    Mori, Jun; Zhang, Liyan; Oudit, Gavin Y; Lopaschuk, Gary D


    The renin-angiotensin system (RAS) plays a key pathogenic role in heart failure. The adverse effects of angiotensin II (Ang II), a major player of the RAS, contributes to the development of heart failure. Heart failure is accompanied by significant perturbations in cardiac energy metabolism that can both decrease cardiac energy supply and decrease cardiac efficiency. Recent evidence suggests that Ang II might be involved in these perturbations in cardiac energy metabolism. Furthermore, new components of the RAS, such as angiotensin converting enzyme 2 and Ang1-7, have been reported to exert beneficial effects on cardiac energy metabolism. As a result, a further understanding of the relationship between the RAS and cardiac energy metabolism has the potential to improve the control of heart failure, and may lead to the development of new therapies to treat heart failure. This review summarizes what effects the RAS has on cardiac energy metabolism, highlighting how Ang II can induce cardiac insulin resistance and mitochondrial damage, and what role reactive oxygen species and sirtuins have on these processes.

  20. Mitochondrial cholesterol: mechanisms of import and effects on mitochondrial function. (United States)

    Martin, Laura A; Kennedy, Barry E; Karten, Barbara


    Mitochondria require cholesterol for biogenesis and membrane maintenance, and for the synthesis of steroids, oxysterols and hepatic bile acids. Multiple pathways mediate the transport of cholesterol from different subcellular pools to mitochondria. In steroidogenic cells, the steroidogenic acute regulatory protein (StAR) interacts with a mitochondrial protein complex to mediate cholesterol delivery to the inner mitochondrial membrane for conversion to pregnenolone. In non-steroidogenic cells, several members of a protein family defined by the presence of a StAR-related lipid transfer (START) domain play key roles in the delivery of cholesterol to mitochondrial membranes. Subdomains of the endoplasmic reticulum (ER), termed mitochondria-associated ER membranes (MAM), form membrane contact sites with mitochondria and may contribute to the transport of ER cholesterol to mitochondria, either independently or in conjunction with lipid-transfer proteins. Model systems of mitochondria enriched with cholesterol in vitro and mitochondria isolated from cells with (patho)physiological mitochondrial cholesterol accumulation clearly demonstrate that mitochondrial cholesterol levels affect mitochondrial function. Increased mitochondrial cholesterol levels have been observed in several diseases, including cancer, ischemia, steatohepatitis and neurodegenerative diseases, and influence disease pathology. Hence, a deeper understanding of the mechanisms maintaining mitochondrial cholesterol homeostasis may reveal additional targets for therapeutic intervention. Here we give a brief overview of mitochondrial cholesterol import in steroidogenic cells, and then focus on cholesterol trafficking pathways that deliver cholesterol to mitochondrial membranes in non-steroidogenic cells. We also briefly discuss the consequences of increased mitochondrial cholesterol levels on mitochondrial function and their potential role in disease pathology.

  1. Mitochondrial Energetics and Therapeutics



    Mitochondrial dysfunction has been linked to a wide range of degenerative and metabolic diseases, cancer, and aging. All these clinical manifestations arise from the central role of bioenergetics in cell biology. Although genetic therapies are maturing as the rules of bioenergetic genetics are clarified, metabolic therapies have been ineffectual. This failure results from our limited appreciation of the role of bioenergetics as the interface between the environment and the cell. A systems app...

  2. Sealing the Mitochondrial Respirasome


    Winge, Dennis R.


    The mitochondrial respiratory chain is organized within an array of supercomplexes that function to minimize the generation of reactive oxygen species (ROS) during electron transfer reactions. Structural models of supercomplexes are now known. Another recent advance is the discovery of non-OXPHOS complex proteins that appear to adhere to and seal the individual respiratory complexes to form stable assemblages that prevent electron leakage. This review highlights recent advances in our underst...

  3. Acetylation control of cardiac fatty acid β-oxidation and energy metabolism in obesity, diabetes, and heart failure. (United States)

    Fukushima, Arata; Lopaschuk, Gary D


    Alterations in cardiac energy metabolism are an important contributor to the cardiac pathology associated with obesity, diabetes, and heart failure. High rates of fatty acid β-oxidation with cardiac insulin resistance represent a cardiac metabolic hallmark of diabetes and obesity, while a marginal decrease in fatty acid oxidation and a prominent decrease in insulin-stimulated glucose oxidation are commonly seen in the early stages of heart failure. Alterations in post-translational control of energy metabolic processes have recently been identified as an important contributor to these metabolic changes. In particular, lysine acetylation of non-histone proteins, which controls a diverse family of mitochondrial metabolic pathways, contributes to the cardiac energy derangements seen in obesity, diabetes, and heart failure. Lysine acetylation is controlled both via acetyltransferases and deacetylases (sirtuins), as well as by non-enzymatic lysine acetylation due to increased acetyl CoA pool size or dysregulated nicotinamide adenine dinucleotide (NAD(+)) metabolism (which stimulates sirtuin activity). One of the important mitochondrial acetylation targets are the fatty acid β-oxidation enzymes, which contributes to alterations in cardiac substrate preference during the course of obesity, diabetes, and heart failure, and can ultimately lead to cardiac dysfunction in these disease states. This review will summarize the role of lysine acetylation and its regulatory control in the context of mitochondrial fatty acid β-oxidation. The functional contribution of cardiac protein lysine acetylation to the shift in cardiac energy substrate preference that occurs in obesity, diabetes, and especially in the early stages of heart failure will also be reviewed. This article is part of a Special Issue entitled: The role of post-translational protein modifications on heart and vascular metabolism edited by Jason R.B. Dyck & Jan F.C. Glatz.

  4. Brachydactylia As A Phenotypic Feature of Mitochondrial Disorder

    Directory of Open Access Journals (Sweden)

    Walter Strobl


    Full Text Available Mitochondrial disorders (MIDs may occasionaly go along with dysmorphism but hand deformities, as in the following case, have been only rarely reported. A 72 year old female with ptosis, hypoacusis, tremor, myopathy, diabetes mellitus, arterial hypertension, severe cardiac disease, pulmonary hypertension, gastric carcinoid, hepatopathy, generalised atherosclerosis, anemia, polyarthrosis, and hyperlipidemia, additionally presented with brachydactylia. Upon neurological work-up a MID was suspected. The family history was positive for diabetes but negative for brachydactylia or other features of a MID. MIDs may be associated with brachydactylia. Skeletal deformities may be a phenotypic manifestation of MIDs

  5. Mitochondrial Peroxiredoxin-3 protects against hyperglycemia induced myocardial damage in Diabetic cardiomyopathy. (United States)

    Arkat, Silpa; Umbarkar, Prachi; Singh, Sarojini; Sitasawad, Sandhya L


    Mitochondrial oxidative stress has emerged as a key contributor towards the development of diabetic cardiomyopathy. Peroxiredoxin-3 (Prx-3), a mitochondrial antioxidant, scavenges H2O2 and offers protection against ROS related pathologies. We observed a decrease in the expression of Prx-3 in the hearts of streptozotocin (STZ) induced diabetic rats, and also high glucose treated H9c2 cardiac cells, which may augment oxidative stress mediated damage. Hence we hypothesized that overexpression of Prx-3 could prevent the cardiac damage associated with diabetes. In this study we used quercetin (QUE) to achieve Prx-3 induction in vivo, while a Prx-3 overexpressing H9c2 cell line was employed for carrying out in vitro studies. Diabetes was induced in Wistar rats by a single intraperitoneal injection of STZ. Quercetin (50mg/kg body weight) was delivered orally to hyperglycemic and age matched control rats for 2 months. Quercetin treatment induced the myocardial expression of Prx-3 but not Prx-5 both in control and STZ rats. Prx-3 induction by quercetin prevented diabetes induced oxidative stress as confirmed by decrease in expression of markers such as 4-HNE and mitochondrial uncoupling protein, UCP-3. It was also successful in reducing cardiac cell apoptosis, hypertrophy and fibrosis leading to amelioration of cardiac contractility defects. Overexpression of Prx-3 in cultured H9c2 cardiac cells could significantly diminish high glucose inflicted mitochondrial oxidative damage and apoptosis, thus strengthening our hypothesis. These results suggest that diabetes induced cardiomyopathy can be prevented by elevating Prx-3 levels thereby providing extensive protection to the diabetic heart.

  6. Sphingolipids and mitochondrial apoptosis. (United States)

    Patwardhan, Gauri A; Beverly, Levi J; Siskind, Leah J


    The sphingolipid family of lipids modulate several cellular processes, including proliferation, cell cycle regulation, inflammatory signaling pathways, and cell death. Several members of the sphingolipid pathway have opposing functions and thus imbalances in sphingolipid metabolism result in deregulated cellular processes, which cause or contribute to diseases and disorders in humans. A key cellular process regulated by sphingolipids is apoptosis, or programmed cell death. Sphingolipids play an important role in both extrinsic and intrinsic apoptotic pathways depending on the stimuli, cell type and cellular response to the stress. During mitochondrial-mediated apoptosis, multiple pathways converge on mitochondria and induce mitochondrial outer membrane permeabilization (MOMP). MOMP results in the release of intermembrane space proteins such as cytochrome c and Apaf1 into the cytosol where they activate the caspases and DNases that execute cell death. The precise molecular components of the pore(s) responsible for MOMP are unknown, but sphingolipids are thought to play a role. Here, we review evidence for a role of sphingolipids in the induction of mitochondrial-mediated apoptosis with a focus on potential underlying molecular mechanisms by which altered sphingolipid metabolism indirectly or directly induce MOMP. Data available on these mechanisms is reviewed, and the focus and limitations of previous and current studies are discussed to present important unanswered questions and potential future directions.

  7. Mitochondrial ABC transporters. (United States)

    Lill, R; Kispal, G


    In contrast to bacteria, mitochondria contain only a few ATP binding cassette (ABC) transporters in their inner membrane. The known mitochondrial ABC proteins fall into two major classes that, in the yeast Saccharomyces cerevisiae, are represented by the half-transporter Atm1p and the two closely homologous proteins Mdl1p and Mdl2p. In humans two Atm1p orthologues (ABC7 and MTABC3) and two proteins homologous to Mdll/2p have been localized to mitochondria. The Atm1p-like proteins perform an important function in mitochondrial iron homeostasis and in the maturation of Fe/S proteins in the cytosol. Mutations in ABC7 are causative of hereditary X-linked sideroblastic anemia and cerebellar ataxia (XLSA/A). MTABC3 may be a candidate gene for the lethal neonatal syndrome. The function of the mitochondrial Mdl1/2p-like proteins is not clear at present with the notable exception of murine ABC-me that may transport intermediates of heme biosynthesis from the matrix to the cytosol in erythroid tissues.

  8. Replicating animal mitochondrial DNA

    Directory of Open Access Journals (Sweden)

    Emily A. McKinney


    Full Text Available The field of mitochondrial DNA (mtDNA replication has been experiencing incredible progress in recent years, and yet little is certain about the mechanism(s used by animal cells to replicate this plasmid-like genome. The long-standing strand-displacement model of mammalian mtDNA replication (for which single-stranded DNA intermediates are a hallmark has been intensively challenged by a new set of data, which suggests that replication proceeds via coupled leading-and lagging-strand synthesis (resembling bacterial genome replication and/or via long stretches of RNA intermediates laid on the mtDNA lagging-strand (the so called RITOLS. The set of proteins required for mtDNA replication is small and includes the catalytic and accessory subunits of DNA polymerase y, the mtDNA helicase Twinkle, the mitochondrial single-stranded DNA-binding protein, and the mitochondrial RNA polymerase (which most likely functions as the mtDNA primase. Mutations in the genes coding for the first three proteins are associated with human diseases and premature aging, justifying the research interest in the genetic, biochemical and structural properties of the mtDNA replication machinery. Here we summarize these properties and discuss the current models of mtDNA replication in animal cells.

  9. Perioperative management of cardiac disease. (United States)

    Aresti, N A; Malik, A A; Ihsan, K M; Aftab, S M E; Khan, W S


    Pre-existing cardiac disease contributes significantly to morbidity and mortality amongst patients undergoing non cardiac surgery. Patients with pre-existing cardiac disease or with risk factors for it, have as much as a 3.9% risk of suffering a major perioperative cardiac event (Lee et al 1999, Devereaux 2005). Furthermore, the incidence of perioperative myocardial infarction (MI) is increased 10 to 50 fold in patients with previous coronary events (Jassal 2008).

  10. Reductive stress impairs myoblasts mitochondrial function and triggers mitochondrial hormesis. (United States)

    Singh, François; Charles, Anne-Laure; Schlagowski, Anna-Isabel; Bouitbir, Jamal; Bonifacio, Annalisa; Piquard, François; Krähenbühl, Stephan; Geny, Bernard; Zoll, Joffrey


    Even though oxidative stress damage from excessive production of ROS is a well known phenomenon, the impact of reductive stress remains poorly understood. This study tested the hypothesis that cellular reductive stress could lead to mitochondrial malfunction, triggering a mitochondrial hormesis (mitohormesis) phenomenon able to protect mitochondria from the deleterious effects of statins. We performed several in vitro experiments on L6 myoblasts and studied the effects of N-acetylcysteine (NAC) at different exposure times. Direct NAC exposure (1mM) led to reductive stress, impairing mitochondrial function by decreasing maximal mitochondrial respiration and increasing H₂O₂production. After 24h of incubation, the reactive oxygen species (ROS) production was increased. The resulting mitochondrial oxidation activated mitochondrial biogenesis pathways at the mRNA level. After one week of exposure, mitochondria were well-adapted as shown by the decrease of cellular ROS, the increase of mitochondrial content, as well as of the antioxidant capacities. Atorvastatin (ATO) exposure (100μM) for 24h increased ROS levels, reduced the percentage of live cells, and increased the total percentage of apoptotic cells. NAC exposure during 3days failed to protect cells from the deleterious effects of statins. On the other hand, NAC pretreatment during one week triggered mitochondrial hormesis and reduced the deleterious effect of statins. These results contribute to a better understanding of the redox-dependant pathways linked to mitochondria, showing that reductive stress could trigger mitochondrial hormesis phenomenon.

  11. 27 CFR 70.482 - Offers in compromise of liabilities (other than forfeiture) under 26 U.S.C. (United States)


    ... 26 U.S.C. (a) In general. The appropriate TTB officer may compromise any civil or criminal liability... liability. (b) Scope of compromise agreement. A compromise agreement may relate to civil or criminal.... However, acceptance of an offer in compromise of a civil liability does not remit a criminal...

  12. Desmin common mutation is associated with multi-systemic disease manifestations and depletion of mitochondria and mitochondrial DNA

    Directory of Open Access Journals (Sweden)

    Elizabeth eMcCormick


    Full Text Available Desmin (DES is a major muscle scaffolding protein that also functions to anchor mitochondria. Pathogenic DES mutations, however, have not previously been recognized as a cause of multi-systemic mitochondrial disease. Here, we describe a 45-year-old man who presented to The Children’s Hospital of Philadelphia Mitochondrial-Genetics Diagnostic Clinic for evaluation of progressive cardiac, neuromuscular, gastrointestinal, and mood disorders. Muscle biopsy at age 45 was remarkable for cytoplasmic bodies, as well as ragged red fibers and SDH positive/COX negative fibers that were suggestive of a mitochondrial myopathy. Muscle also showed significant reductions in mitochondrial content (16% of control mean for citrate synthase activity and mitochondrial DNA (35% of control mean. His family history was significant for cardiac conduction defects and myopathy in multiple maternal relatives. Multiple single gene and panel-based sequencing studies were unrevealing. Whole exome sequencing identified a known pathogenic p.S13F mutation in DES that had previously been associated with desmin-related myopathy. Desmin-related myopathy is an autosomal dominant disorder characterized by right ventricular hypertrophic cardiomyopathy, myopathy, and arrhythmias. However, neuropathy, gastrointestinal dysfunction, and depletion of both mitochondria and mitochondrial DNA have not previously been widely recognized in this disorder. Recognition that mitochondrial dysfunction occurs in desmin-related myopathy clarifies the basis for the multi-systemic manifestations, as are typical of primary mitochondrial disorders. Understanding the mitochondrial pathophysiology of desmin-related myopathy highlights the possibility of new therapies for the otherwise untreatable and often fatal class of disease. We postulate that drug treatments aimed at improving mitochondrial biogenesis or reducing oxidative stress may be effective therapies to ameliorate the effects of desmin

  13. Desmin common mutation is associated with multi-systemic disease manifestations and depletion of mitochondria and mitochondrial DNA. (United States)

    McCormick, Elizabeth M; Kenyon, Lawrence; Falk, Marni J


    Desmin (DES) is a major muscle scaffolding protein that also functions to anchor mitochondria. Pathogenic DES mutations, however, have not previously been recognized as a cause of multi-systemic mitochondrial disease. Here, we describe a 45-year-old man who presented to The Children's Hospital of Philadelphia Mitochondrial-Genetics Diagnostic Clinic for evaluation of progressive cardiac, neuromuscular, gastrointestinal, and mood disorders. Muscle biopsy at age 45 was remarkable for cytoplasmic bodies, as well as ragged red fibers and SDH positive/COX negative fibers that were suggestive of a mitochondrial myopathy. Muscle also showed significant reductions in mitochondrial content (16% of control mean for citrate synthase activity) and mitochondrial DNA (35% of control mean). His family history was significant for cardiac conduction defects and myopathy in multiple maternal relatives. Multiple single gene and panel-based sequencing studies were unrevealing. Whole exome sequencing identified a known pathogenic p.S13F mutation in DES that had previously been associated with desmin-related myopathy. Desmin-related myopathy is an autosomal dominant disorder characterized by right ventricular hypertrophic cardiomyopathy, myopathy, and arrhythmias. However, neuropathy, gastrointestinal dysfunction, and depletion of both mitochondria and mitochondrial DNA have not previously been widely recognized in this disorder. Recognition that mitochondrial dysfunction occurs in desmin-related myopathy clarifies the basis for the multi-systemic manifestations, as are typical of primary mitochondrial disorders. Understanding the mitochondrial pathophysiology of desmin-related myopathy highlights the possibility of new therapies for this otherwise untreatable and often fatal class of disease. We postulate that drug treatments aimed at improving mitochondrial biogenesis or reducing oxidative stress may be effective therapies to ameliorate the effects of desmin-related disease.

  14. Galnt1 is required for normal heart valve development and cardiac function.

    Directory of Open Access Journals (Sweden)

    E Tian

    Full Text Available Congenital heart valve defects in humans occur in approximately 2% of live births and are a major source of compromised cardiac function. In this study we demonstrate that normal heart valve development and cardiac function are dependent upon Galnt1, the gene that encodes a member of the family of glycosyltransferases (GalNAc-Ts responsible for the initiation of mucin-type O-glycosylation. In the adult mouse, compromised cardiac function that mimics human congenital heart disease, including aortic and pulmonary valve stenosis and regurgitation; altered ejection fraction; and cardiac dilation, was observed in Galnt1 null animals. The underlying phenotype is aberrant valve formation caused by increased cell proliferation within the outflow tract cushion of developing hearts, which is first detected at developmental stage E11.5. Developing valves from Galnt1 deficient animals displayed reduced levels of the proteases ADAMTS1 and ADAMTS5, decreased cleavage of the proteoglycan versican and increased levels of other extracellular matrix proteins. We also observed increased BMP and MAPK signaling. Taken together, the ablation of Galnt1 appears to disrupt the formation/remodeling of the extracellular matrix and alters conserved signaling pathways that regulate cell proliferation. Our study provides insight into the role of this conserved protein modification in cardiac valve development and may represent a new model for idiopathic valve disease.

  15. Mitochondrial alterations, oxidative stress and neuroinflammation in Alzheimer's disease. (United States)

    Verri, M; Pastoris, O; Dossena, M; Aquilani, R; Guerriero, F; Cuzzoni, G; Venturini, L; Ricevuti, G; Bongiorno, A I


    Alzheimer's disease (AD) is a multifactorial disorder characterized by the progressive deterioration of neuronal networks. The primary cause and sequence of its progression are only partially understood but abnormalities in folding and accumulation of insoluble proteins such as beta-amyloid and Tau-protein are both associated with the pathogenesis of AD. Mitochondria play a crucial role in cell survival and death, and changes in mitochondrial structure and/or function are related to many human diseases. Increasing evidence suggests that compromised mitochondrial function contributes to the aging process and thus may increase the risk of AD. Dysfunctional mitochondria contribute to reactive oxygen species which can lead to extensive macromolecule oxidative damage and the progression of amyloid pathology. Oxidative stress and amyloid toxicity leave neurons chemically vulnerable. The mitochondrial toxicity induced by beta-amyloid is still not clear but may include numerous mechanisms, such as the increased permeability of mitochondrial membranes, the disruption of calcium homeostasis, the alteration of oxidative phosphorylation with a consequent overproduction of reactive oxygen species. Other mechanisms have been associated with the pathophysiology of AD. Inflammatory changes are observed in AD brain overall, particularly at the amyloid deposits, which are rich in activated microglia. Once stimulated, the microglia release a wide variety of pro-inflammatory mediators including cytokines, complement components and free radicals, all of which potentially contribute to further neuronal dysfunction and eventually death. Clinically, novel approaches to visualize early neuroinflammation in the human brain are needed to improve the monitoring and control of therapeutic strategies that target inflammatory and other pathological mechanisms. Similarly, there is growing interest in developing agents that modulate mitochondrial function.

  16. Early effects of the antineoplastic agent salinomycin on mitochondrial function. (United States)

    Managò, A; Leanza, L; Carraretto, L; Sassi, N; Grancara, S; Quintana-Cabrera, R; Trimarco, V; Toninello, A; Scorrano, L; Trentin, L; Semenzato, G; Gulbins, E; Zoratti, M; Szabò, I


    fibroblasts. The results indicate that salinomycin, when used above μM concentrations, exerts direct, mitochondrial effects, thus compromising cell survival.

  17. Fully automated software for quantitative measurements of mitochondrial morphology. (United States)

    McClatchey, P Mason; Keller, Amy C; Bouchard, Ron; Knaub, Leslie A; Reusch, Jane E B


    Mitochondria undergo dynamic changes in morphology in order to adapt to changes in nutrient and oxygen availability, communicate with the nucleus, and modulate intracellular calcium dynamics. Many recent papers have been published assessing mitochondrial morphology endpoints. Although these studies have yielded valuable insights, contemporary assessment of mitochondrial morphology is typically subjective and qualitative, precluding direct comparison of outcomes between different studies and likely missing many subtle effects. In this paper, we describe a novel software technique for measuring the average length, average width, spatial density, and intracellular localization of mitochondria from a fluorescent microscope image. This method was applied to distinguish baseline characteristics of Human Umbilical Vein Endothelial Cells (HUVECs), primary Goto-Kakizaki rat aortic smooth muscle cells (GK SMCs), primary Wistar rat aortic smooth muscle cells (Wistar SMCs), and SH-SY5Ys (human neuroblastoma cell line). Consistent with direct observation, our algorithms found SH-SY5Ys to have the greatest mitochondrial density, while HUVECs were found to have the longest mitochondria. Mitochondrial morphology responses to temperature, nutrient, and oxidative stressors were characterized to test algorithm performance. Large morphology changes recorded by the software agreed with direct observation, and subtle but consistent morphology changes were found that would not otherwise have been detected. Endpoints were consistent between experimental repetitions (R=0.93 for length, R=0.93 for width, R=0.89 for spatial density, and R=0.74 for localization), and maintained reasonable agreement even when compared to images taken with compromised microscope resolution or in an alternate imaging plane. These results indicate that the automated software described herein allows quantitative and objective characterization of mitochondrial morphology from fluorescent microscope images.

  18. The Mitochondrial Calcium Uniporter Selectively Matches Metabolic Output to Acute Contractile Stress in the Heart

    Directory of Open Access Journals (Sweden)

    Jennifer Q. Kwong


    Full Text Available In the heart, augmented Ca2+ fluxing drives contractility and ATP generation through mitochondrial Ca2+ loading. Pathologic mitochondrial Ca2+ overload with ischemic injury triggers mitochondrial permeability transition pore (MPTP opening and cardiomyocyte death. Mitochondrial Ca2+ uptake is primarily mediated by the mitochondrial Ca2+ uniporter (MCU. Here, we generated mice with adult and cardiomyocyte-specific deletion of Mcu, which produced mitochondria refractory to acute Ca2+ uptake, with impaired ATP production, and inhibited MPTP opening upon acute Ca2+ challenge. Mice lacking Mcu in the adult heart were also protected from acute ischemia-reperfusion injury. However, resting/basal mitochondrial Ca2+ levels were normal in hearts of Mcu-deleted mice, and mitochondria lacking MCU eventually loaded with Ca2+ after stress stimulation. Indeed, Mcu-deleted mice were unable to immediately sprint on a treadmill unless warmed up for 30 min. Hence, MCU is a dedicated regulator of short-term mitochondrial Ca2+ loading underlying a “fight-or-flight” response that acutely matches cardiac workload with ATP production.

  19. Mitochondrial complex I dysfunction induced by cocaine and cocaine plus morphine in brain and liver mitochondria. (United States)

    Cunha-Oliveira, Teresa; Silva, Lisbeth; Silva, Ana Maria; Moreno, António J; Oliveira, Catarina R; Santos, Maria S


    Mitochondrial function and energy metabolism are affected in brains of human cocaine abusers. Cocaine is known to induce mitochondrial dysfunction in cardiac and hepatic tissues, but its effects on brain bioenergetics are less documented. Furthermore, the combination of cocaine and opioids (speedball) was also shown to induce mitochondrial dysfunction. In this work, we compared the effects of cocaine and/or morphine on the bioenergetics of isolated brain and liver mitochondria, to understand their specific effects in each tissue. Upon energization with complex I substrates, cocaine decreased state-3 respiration in brain (but not in liver) mitochondria and decreased uncoupled respiration and mitochondrial potential in both tissues, through a direct effect on complex I. Morphine presented only slight effects on brain and liver mitochondria, and the combination cocaine+morphine had similar effects to cocaine alone, except for a greater decrease in state-3 respiration. Brain and liver mitochondrial respirations were differentially affected, and liver mitochondria were more prone to proton leak caused by the drugs or their combination. This was possibly related with a different dependence on complex I in mitochondrial populations from these tissues. In summary, cocaine and cocaine+morphine induce mitochondrial complex I dysfunction in isolated brain and liver mitochondria, with specific effects in each tissue.

  20. Mechanisms of disease: Mitochondrial dysfunction in sensory neuropathy and other complications in diabetes. (United States)

    Fernyhough, Paul; McGavock, Jonathan


    Diabetic neuropathy is a major complication of diabetes that involves the sensory and autonomic nervous systems and leads to significant morbidity and impact on quality of life of patients. Mitochondrial stress has been proposed as a major mediator of insulin sensitivity in skeletal muscle in type 2 diabetes and a trigger of diabetic complications such as nephropathy and cardiomyopathy in humans and animal models. Recent studies in the peripheral nervous system in type 1 and type 2 diabetic animal models suggest a role for mitochondrial dysfunction in neurodegeneration in diabetes. This chapter focuses on the nature of sensory nerve dysfunction in diabetes and presents these findings in the context of diabetes-induced nerve degeneration mediated by alterations in mitochondrial physiology. Diabetes-induced dysfunction in calcium homeostasis is discussed and causative associations with suboptimal mitochondrial physiology are developed. Comparisons are made with mitochondrial-dependent dysfunction in muscle and cardiac tissue in diabetes. It is clear that across a range of complications of diabetes mitochondrial physiology is impaired; in general, a reduction in respiratory chain capability is apparent. Where appropriate, we provide clinical evidence for mitochondrial dysfunction in the pathogenesis of complications in patients with diabetes. This abnormal activity may predispose mitochondria to generate elevated reactive oxygen species (ROS), although experimental proof remains lacking, but more importantly will deleteriously alter the bioenergetic status of neurons.

  1. Mitochondrial integrity in a neonatal bovine model of right ventricular dysfunction. (United States)

    Bruns, Danielle R; Brown, R Dale; Stenmark, Kurt R; Buttrick, Peter M; Walker, Lori A


    Right ventricular (RV) function is a key determinant of survival in patients with both RV and left ventricular (LV) failure, yet the mechanisms of RV failure are poorly understood. Recent studies suggest cardiac metabolism is altered in RV failure in pulmonary hypertension (PH). Accordingly, we assessed mitochondrial content, dynamics, and function in hearts from neonatal calves exposed to hypobaric hypoxia (HH). This model develops severe PH with concomitant RV hypertrophy, dilation, and dysfunction. After 2 wk of HH, pieces of RV and LV were obtained along with samples from age-matched controls. Comparison with control assesses the effect of hypoxia, whereas comparison between the LV and RV in HH assesses the additional impact of RV overload. Mitochondrial DNA was unchanged in HH, as was mitochondrial content as assessed by electron microscopy. Immunoblotting for electron transport chain subunits revealed a small increase in mitochondrial content in HH in both ventricles. Mitochondrial dynamics were largely unchanged. Activity of individual respiratory chain complexes was reduced (complex I) or unchanged (complex V) in HH. Key enzymes in the glycolysis pathway were upregulated in both HH ventricles, alongside upregulation of hypoxia-inducible factor-1α protein. Importantly, none of the changes in expression or activity were different between ventricles, suggesting the changes are in response to HH and not RV overload. Upregulation of glycolytic modulators without chamber-specific mitochondrial dysfunction suggests that mitochondrial capacity and activity are maintained at the onset of PH, and the early RV dysfunction in this model results from mechanisms independent of the mitochondria.

  2. The Mitochondrial Calcium Uniporter Selectively Matches Metabolic Output to Acute Contractile Stress in the Heart. (United States)

    Kwong, Jennifer Q; Lu, Xiyuan; Correll, Robert N; Schwanekamp, Jennifer A; Vagnozzi, Ronald J; Sargent, Michelle A; York, Allen J; Zhang, Jianyi; Bers, Donald M; Molkentin, Jeffery D


    In the heart, augmented Ca(2+) fluxing drives contractility and ATP generation through mitochondrial Ca(2+) loading. Pathologic mitochondrial Ca(2+) overload with ischemic injury triggers mitochondrial permeability transition pore (MPTP) opening and cardiomyocyte death. Mitochondrial Ca(2+) uptake is primarily mediated by the mitochondrial Ca(2+) uniporter (MCU). Here, we generated mice with adult and cardiomyocyte-specific deletion of Mcu, which produced mitochondria refractory to acute Ca(2+) uptake, with impaired ATP production, and inhibited MPTP opening upon acute Ca(2+) challenge. Mice lacking Mcu in the adult heart were also protected from acute ischemia-reperfusion injury. However, resting/basal mitochondrial Ca(2+) levels were normal in hearts of Mcu-deleted mice, and mitochondria lacking MCU eventually loaded with Ca(2+) after stress stimulation. Indeed, Mcu-deleted mice were unable to immediately sprint on a treadmill unless warmed up for 30 min. Hence, MCU is a dedicated regulator of short-term mitochondrial Ca(2+) loading underlying a "fight-or-flight" response that acutely matches cardiac workload with ATP production.

  3. Data analysis in cardiac arrhythmias. (United States)

    Rodrigo, Miguel; Pedrón-Torecilla, Jorge; Hernández, Ismael; Liberos, Alejandro; Climent, Andreu M; Guillem, María S


    Cardiac arrhythmias are an increasingly present in developed countries and represent a major health and economic burden. The occurrence of cardiac arrhythmias is closely linked to the electrical function of the heart. Consequently, the analysis of the electrical signal generated by the heart tissue, either recorded invasively or noninvasively, provides valuable information for the study of cardiac arrhythmias. In this chapter, novel cardiac signal analysis techniques that allow the study and diagnosis of cardiac arrhythmias are described, with emphasis on cardiac mapping which allows for spatiotemporal analysis of cardiac signals.Cardiac mapping can serve as a diagnostic tool by recording cardiac signals either in close contact to the heart tissue or noninvasively from the body surface, and allows the identification of cardiac sites responsible of the development or maintenance of arrhythmias. Cardiac mapping can also be used for research in cardiac arrhythmias in order to understand their mechanisms. For this purpose, both synthetic signals generated by computer simulations and animal experimental models allow for more controlled physiological conditions and complete access to the organ.

  4. Biosynthesis of cardiac natriuretic peptides

    DEFF Research Database (Denmark)

    Goetze, Jens Peter


    Cardiac-derived peptide hormones were identified more than 25 years ago. An astonishing amount of clinical studies have established cardiac natriuretic peptides and their molecular precursors as useful markers of heart disease. In contrast to the clinical applications, the biogenesis of cardiac...

  5. Cardiac arrest in intensive care unit: Case report and future recommendations

    Directory of Open Access Journals (Sweden)

    Mohammad A


    Full Text Available Initiation of hemofiltration in a patient in septic shock can cause hemodynamic compromise potentially leading to cardiac arrest. We propose that the standard ′4Hs and 4Ts′ approach to the differential diagnosis of a cardiac arrest should be supplemented in critically ill patients with anaphylaxis and human and technical errors involving drug administration (the 5 th H and T. To illustrate the point, we report a case where norepinephrine infused through a central venous catheter (CVC was being removed by the central venovenous hemofiltration (CVVH catheter causing the hemodynamic instability. CVVH has this potential of interfering with the systemic availability of drugs infused via a closely located CVC.

  6. Effects of a single terlipressin administration on cardiac function and perfusion in cirrhosis

    DEFF Research Database (Denmark)

    Krag, Aleksander; Bendtsen, Flemming; Mortensen, Christian


    BACKGROUND: The vasoconstrictor terlipressin is widely used in the treatment of the hepatorenal syndrome and variceal bleeding. However, terlipressin may compromise cardiac function and induce ischemia. AIM: Therefore, we aimed to assess the effects of terlipressin on cardiac function and perfusion...... with nonrefractory ascites, both at baseline and after terlipressin treatment. The decrease in the left ventricular wall thickening and wall motion correlated with the Child--Pugh score, r=-0.59, P=0.005 and r=-0.48, P=0.03. CONCLUSION: In advanced cirrhosis, the increase in afterload and EDV after terlipressin...

  7. Cardiac troponins and high-sensitivity cardiac troponin assays. (United States)

    Conrad, Michael J; Jarolim, Petr


    Measurement of circulating cardiac troponins I and T has become integral to the diagnosis of myocardial infarction. This article discusses the structure and function of the troponin complex and the release of cardiac troponin molecules from the injured cardiomyocyte into the circulation. An overview of current cardiac troponin assays and their classification according to sensitivity is presented. The diagnostic criteria, role, and usefulness of cardiac troponin for myocardial infarction are discussed. In addition, several examples are given of the usefulness of high-sensitivity cardiac troponin assays for short-term and long-term prediction of adverse events.

  8. Effect of heat stress on cardiac output and systemic vascular conductance during simulated hemorrhage to presyncope in young men

    DEFF Research Database (Denmark)

    Ganio, Matthew S; Overgaard, Morten; Seifert, Thomas;


    During moderate actual or simulated hemorrhage, as cardiac output decreases, reductions in systemic vascular conductance (SVC) maintain mean arterial pressure (MAP). Heat stress, however, compromises the control of MAP during simulated hemorrhage, and it remains unknown whether this response is due...... to a persistently high SVC and/or a low cardiac output. This study tested the hypothesis that an inadequate decrease in SVC is the primary contributing mechanism by which heat stress compromises blood pressure control during simulated hemorrhage. Simulated hemorrhage was imposed via lower body negative pressure...... (LBNP) to presyncope in 11 passively heat-stressed subjects (increase core temperature: 1.2 ± 0.2°C; means ± SD). Cardiac output was measured via thermodilution, and SVC was calculated while subjects were normothermic, heat stressed, and throughout subsequent LBNP. MAP was not changed by heat stress...

  9. Cannabidiol Protects against Doxorubicin-Induced Cardiomyopathy by Modulating Mitochondrial Function and Biogenesis. (United States)

    Hao, Enkui; Mukhopadhyay, Partha; Cao, Zongxian; Erdélyi, Katalin; Holovac, Eileen; Liaudet, Lucas; Lee, Wen-Shin; Haskó, György; Mechoulam, Raphael; Pacher, Pál


    Doxorubicin (DOX) is a widely used, potent chemotherapeutic agent; however, its clinical application is limited because of its dose-dependent cardiotoxicity. DOX's cardiotoxicity involves increased oxidative/nitrative stress, impaired mitochondrial function in cardiomyocytes/endothelial cells and cell death. Cannabidiol (CBD) is a nonpsychotropic constituent of marijuana, which is well tolerated in humans, with antioxidant, antiinflammatory and recently discovered antitumor properties. We aimed to explore the effects of CBD in a well-established mouse model of DOX-induced cardiomyopathy. DOX-induced cardiomyopathy was characterized by increased myocardial injury (elevated serum creatine kinase and lactate dehydrogenase levels), myocardial oxidative and nitrative stress (decreased total glutathione content and glutathione peroxidase 1 activity, increased lipid peroxidation, 3-nitrotyrosine formation and expression of inducible nitric oxide synthase mRNA), myocardial cell death (apoptotic and poly[ADP]-ribose polymerase 1 [PARP]-dependent) and cardiac dysfunction (decline in ejection fraction and left ventricular fractional shortening). DOX also impaired myocardial mitochondrial biogenesis (decreased mitochondrial copy number, mRNA expression of peroxisome proliferator-activated receptor γ coactivator 1-alpha, peroxisome proliferator-activated receptor alpha, estrogen-related receptor alpha), reduced mitochondrial function (attenuated complex I and II activities) and decreased myocardial expression of uncoupling protein 2 and 3 and medium-chain acyl-CoA dehydrogenase mRNA. Treatment with CBD markedly improved DOX-induced cardiac dysfunction, oxidative/nitrative stress and cell death. CBD also enhanced the DOX-induced impaired cardiac mitochondrial function and biogenesis. These data suggest that CBD may represent a novel cardioprotective strategy against DOX-induced cardiotoxicity, and the above-described effects on mitochondrial function and biogenesis may

  10. Therapeutic inhibition of mitochondrial reactive oxygen species with mito-TEMPO reduces diabetic cardiomyopathy (United States)

    Ni, Rui; Cao, Ting; Xiong, Sidong; Ma, Jian; Fan, Guo-Chang; Lacefield, James C.; Lu, Yanrong; Le Tissier, Sydney; Peng, Tianqing


    Aims The mitochondria are important sources of reactive oxygen species (ROS) in the heart. Mitochondrial ROS production has been implicated in the pathogenesis of diabetic cardiomyopathy, suggesting that therapeutic strategies specifically targeting mitochondrial ROS may have benefit in this disease. We investigated the therapeutic effects of mitochondria-targeted antioxidant mito-TEMPO on diabetic cardiomyopathy. Methods The mitochondria-targeted antioxidant mito-TEMPO was administrated after diabetes onset in a mouse model of streptozotocin-induced type-1 diabetes and type-2 diabetic db/db mice. Cardiac adverse changes were analyzed and myocardial function assessed. Cultured adult cardiomyocytes were stimulated with high glucose, and mitochondrial superoxide generation and cell death were measured. Results Incubation with high glucose increased mitochondria superoxide generation in cultured cardiomyocytes, which was prevented by mito-TEMPO. Co-incubation with mito-TEMPO abrogated high glucose-induced cell death. Mitochondrial ROS generation, and intracellular oxidative stress levels were induced in both type-1 and type-2 diabetic mouse hearts. Daily injection of mito-TEMPO for 30 days inhibited mitochondrial ROS generation, prevented intracellular oxidative stress levels, decreased apoptosis and reduced myocardial hypertrophy in diabetic hearts, leading to improvement of myocardial function in both type-1 and type-2 diabetic mice. Incubation with mito-TEMPO or inhibition of Nox2-containing NADPH oxidase prevented oxidative stress levels and cell death in high glucose-stimulated cardiomyocytes. Mechanistic study revealed that the protective effects of mito-TEMPO were associated with down-regulation of ERK1/2 phosphorylation. Conclusions Therapeutic inhibition of mitochondrial ROS by mito-TEMPO reduced adverse cardiac changes and mitigated myocardial dysfunction in diabetic mice. Thus, mitochondria-targeted antioxidants may be an effective therapy for diabetic

  11. The mitochondrial ryanodine receptor in rat heart: a pharmaco-kinetic profile. (United States)

    Altschafl, Beth A; Beutner, Gisela; Sharma, Virendra K; Sheu, Shey-Shing; Valdivia, Héctor H


    A protein discovered within inner mitochondrial membranes (IMM), designated as the mitochondrial ryanodine receptor (mRyR), has been recognized recently as a modulator of Ca(2+) fluxes in mitochondria. The present study provides fundamental pharmacological and electrophysiological properties of this mRyR. Rat cardiac IMM fused to lipid bilayers revealed the presence of a mitochondrial channel with gating characteristics similar to those of classical sarcoplasmic reticulum RyR (SR-RyR), but a variety of other mitochondrial channels obstructed clean recordings. Mitochondrial vesicles were thus solubilized and subjected to sucrose sedimentation to obtain mRyR-enriched fractions. Reconstitution of sucrose-purified fractions into lipid bilayers yielded Cs(+)-conducting, Ca(2+)-sensitive, large conductance (500-800 pS) channels with signature properties of SR-RyRs. Cytosolic Ca(2+) increased the bursting frequency and mean open time of the channel. Micromolar concentrations of ryanodine induced the appearance of subconductance states or inhibited channel activity altogether, while Imperatoxin A (IpTx(a)), a specific activator of RyRs, reversibly induced the appearance of distinct subconductance states. Remarkably, the cardiac mRyR displayed a Ca(2+) dependence of [(3)H]ryanodine binding curve similar to skeletal RyR (RyR1), not cardiac RyR (RyR2). Overall, the mRyR displayed elemental attributes that are present in single channel lipid bilayer recordings of SR-RyRs, although some exquisite differences were also noted. These results therefore provide the first direct evidence that a unique RyR occurs in mitochondrial membranes.

  12. [Cyclosporin A causes oxidative stress and mitochondrial dysfunction in renal tubular cells]. (United States)

    Pérez de Hornedo, J; de Arriba, G; Calvino, M; Benito, S; Parra, T


    Reactive oxygen species (ROS) have been implicated in cyclosporin A (CsA) nephrotoxicity. As mitochondria are one of the main sources of ROS in cells, we evaluated the role of CsA in mitochondrial structure and function in LLC-PK1 cells. We incubated cells with CsA 1 microM for 24 hours and studies were performed with flow citometry and confocal microscopy. We studied mitochondrial NAD(P)H content, superoxide anion (O2.-) production (MitoSOX Red), oxidation of cardiolipin of inner mitochondrial membrane (NAO) and mitochondrial membrane potential (DIOC2(3)). Also we analyzed the intracellular ROS synthesis (H2DCF-DA) and reduced glutation (GSH) of cells. Our results showed that CsA decreased NAD(P)H and membrane potential, and increased O2.- in mitochondria. CsA also provoked oxidation of cardiolipin. Furthermore, CsA increased intracellular ROS production and decreased GSH content. These results suggest that CsA has crucial effects in mitochondria. CsA modified mitochondrial physiology through the decrease of antioxidant mitochondrial compounds as NAD(P)H and the dissipation of mitochondrial membrane potential and increase of oxidants as O2.-. Also, CsA alters lipidic structure of inner mitochondrial membrane through the oxidation of cardiolipin. These effects trigger a chain of events that favour intracellular synthesis of ROS and depletion of GSH that can compromise cellular viability. Nephrotoxic cellular effects of CsA can be explained, at least in part, through its influence on mitochondrial functionalism.

  13. α-MHC MitoTimer mouse: In vivo mitochondrial turnover model reveals remarkable mitochondrial heterogeneity in the heart. (United States)

    Stotland, Aleksandr; Gottlieb, Roberta A


    In order to maintain an efficient, energy-producing network in the heart, dysfunctional mitochondria are cleared through the mechanism of autophagy, which is closely linked with mitochondrial biogenesis; these, together with fusion and fission comprise a crucial process known as mitochondrial turnover. Until recently, the lack of molecular tools and methods available to researchers has impeded in vivo investigations of turnover. To investigate the process at the level of a single mitochondrion, our laboratory has developed the MitoTimer protein. Timer is a mutant of DsRed fluorescent protein characterized by transition from green fluorescence to a more stable red conformation over 48 h, and its rate of maturation is stable under physiological conditions. We fused the Timer cDNA with the inner mitochondrial membrane signal sequence and placed it under the control of a cardiac-restricted promoter. This construct was used to create the alpha-MHC-MitoTimer mice. Surprisingly, initial analysis of the hearts from these mice demonstrated a high degree of heterogeneity in the ratio of red-to-green fluorescence of MitoTimer in cardiac tissue. Further, scattered solitary mitochondria within cardiomyocytes display a much higher red-to-green fluorescence (red-shifted) relative to other mitochondria in the cell, implying a block in import of newly synthesized MitoTimer likely due to lower membrane potential. These red-shifted mitochondria may represent older, senescent mitochondria. Concurrently, the cardiomyocytes also contain a subpopulation of mitochondria that display a lower red-to-green fluorescence (green-shifted) relative to other mitochondria, indicative of germinal mitochondria that are actively engaged in import of newly-synthesized mito-targeted proteins. These mitochondria can be isolated and sorted from the heart by flow cytometry for further analysis. Initial studies suggest that these mice represent an elegant tool for the investigation of mitochondrial turnover

  14. Cardiac and Skeletal Muscle Defects in a Mouse Model of Human Barth Syndrome* (United States)

    Acehan, Devrim; Vaz, Frederic; Houtkooper, Riekelt H.; James, Jeanne; Moore, Vicky; Tokunaga, Chonan; Kulik, Willem; Wansapura, Janaka; Toth, Matthew J.; Strauss, Arnold; Khuchua, Zaza


    Barth syndrome is an X-linked genetic disorder caused by mutations in the tafazzin (taz) gene and characterized by dilated cardiomyopathy, exercise intolerance, chronic fatigue, delayed growth, and neutropenia. Tafazzin is a mitochondrial transacylase required for cardiolipin remodeling. Although tafazzin function has been studied in non-mammalian model organisms, mammalian genetic loss of function approaches have not been used. We examined the consequences of tafazzin knockdown on sarcomeric mitochondria and cardiac function in mice. Tafazzin knockdown resulted in a dramatic decrease of tetralinoleoyl cardiolipin in cardiac and skeletal muscles and accumulation of monolysocardiolipins and cardiolipin molecular species with aberrant acyl groups. Electron microscopy revealed pathological changes in mitochondria, myofibrils, and mitochondrion-associated membranes in skeletal and cardiac muscles. Echocardiography and magnetic resonance imaging revealed severe cardiac abnormalities, including left ventricular dilation, left ventricular mass reduction, and depression of fractional shortening and ejection fraction in tafazzin-deficient mice. Tafazzin knockdown mice provide the first mammalian model system for Barth syndrome in which the pathophysiological relationships between altered content of mitochondrial phospholipids, ultrastructural abnormalities, myocardial and mitochondrial dysfunction, and clinical outcome can be completely investigated. PMID:21068380

  15. Perspectives on the Role and Relevance of Copper in Cardiac Disease. (United States)

    Medeiros, Denis M


    Cardiac hypertrophy as a result of dietary copper deficiency has been studied for 40 plus years and is the subject of this review. While connective tissue anomalies occur, a hallmark pathology is cardiac hypertrophy, increased mitochondrial biogenesis, with disruptive cristae, vacuolization of mitochondria, and deposition of lipid droplets. Electrocardiogram abnormalities have been demonstrated along with biochemical changes especially as it relates to the copper-containing enzyme cytochrome c oxidase. The master controller of mitochondrial biogenesis, PGC1-α expression and protein, along with other proteins and transcriptional factors that play a role are upregulated. Nitric oxide, vascular endothelial growth factor, and cytochrome c oxidase all may enhance the upregulation of mitochondrial biogenesis. Marginal copper intakes reveal similar pathologies in the absence of cardiac hypertrophy. Reversibility of the copper-deficient rat heart with a copper-replete diet has resulted in mixed results, depending on both the animal model used and temporal relationships. New information has revealed that copper supplementation may rescue cardiac hypertrophy induced by pressure overload.

  16. Cardiac potassium channel subtypes

    DEFF Research Database (Denmark)

    Schmitt, Nicole; Grunnet, Morten; Olesen, Søren-Peter


    About 10 distinct potassium channels in the heart are involved in shaping the action potential. Some of the K(+) channels are primarily responsible for early repolarization, whereas others drive late repolarization and still others are open throughout the cardiac cycle. Three main K(+) channels...

  17. Cardiac Risk Assessment (United States)

    ... Risk Assessment Related tests: Lipid Profile , VLDL Cholesterol , hs-CRP , Lp(a) Overview | Common Questions | Related Pages What ... cardiac risk include: High-sensitivity C-reactive protein (hs-CRP) : Studies have shown that measuring CRP with a ...

  18. The cardiac malpositions. (United States)

    Perloff, Joseph K


    Dextrocardia was known in the 17th century and was 1 of the first congenital malformations of the heart to be recognized. Fifty years elapsed before Matthew Baillie published his account of complete transposition in a human of the thoracic and abdominal viscera to the opposite side from what is natural. In 1858, Thomas Peacock stated that "the heart may be congenitally misplaced in various ways, occupying either an unusual position within the thorax, or being situated external to that cavity." In 1915, Maude Abbott described ectopia cordis, and Richard Paltauf's remarkable illustrations distinguished the various types of dextrocardia. In 1928, the first useful classification of the cardiac malpositions was proposed, and in 1966, Elliott et al's radiologic classification set the stage for clinical recognition. The first section of this review deals with the 3 basic cardiac malpositions in the presence of bilateral asymmetry. The second section deals with cardiac malpositions in the presence of bilateral left-sidedness or right-sidedness. Previous publications on cardiac malpositions are replete with an arcane vocabulary that confounds rather than clarifies. Even if the terms themselves are understood, inherent complexity weighs against clarity. This review was designed as a guided tour of an unfamiliar subject.

  19. Hepato-cardiac disorders

    Institute of Scientific and Technical Information of China (English)

    Yasser; Mahrous; Fouad; Reem; Yehia


    Understanding the mutual relationship between the liver and the heart is important for both hepatologists and cardiologists. Hepato-cardiac diseases can be classified into heart diseases affecting the liver, liver diseases affecting the heart, and conditions affecting the heart and the liver at the same time. Differential diagnoses of liver injury are extremely important in a cardiologist’s clinical practice calling for collaboration between cardiologists and hepatologists due to the many other diseases that can affect the liver and mimic haemodynamic injury. Acute and chronic heart failure may lead to acute ischemic hepatitis or chronic congestive hepatopathy. Treatment in these cases should be directed to the primary heart disease. In patients with advanced liver disease, cirrhotic cardiomyopathy may develop including hemodynamic changes, diastolic and systolic dysfunctions, reduced cardiac performance and electrophysiological abnormalities. Cardiac evaluation is important for patients with liver diseases especially before and after liver transplantation. Liver transplantation may lead to the improvement of all cardiac changes and the reversal of cirrhotic cardiomyopathy. There are systemic diseases that may affect both the liver and the heart concomitantly including congenital, metabolic and inflammatory diseases as well as alcoholism. This review highlights these hepatocardiac diseases

  20. 10 CFR 15.41 - When a claim may be compromised. (United States)


    ... it has not been referred to DOJ for litigation. (b) Unless otherwise provided by law, when the... with the DOJ. The NRC will evaluate the compromise offer, using the factors set forth in this part. If an offer to compromise any debt in excess of $100,000 is acceptable to the NRC, the NRC shall...

  1. 13 CFR 108.1710 - SBA authority to collect or compromise its claims. (United States)


    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false SBA authority to collect or compromise its claims. 108.1710 Section 108.1710 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION...) Miscellaneous § 108.1710 SBA authority to collect or compromise its claims. SBA may, upon such conditions...

  2. Compromised motor control in children with DCD: A deficit in the internal model - a systematic review

    NARCIS (Netherlands)

    Adams, I.L.J.; Lust, J.M.; Wilson, P.H.; Steenbergen, B.


    A viable hypothesis to explain the compromised motor ability of children with Developmental Coordination Disorder (DCD) suggests a fundamental deficit in their ability to utilize internal models for motor control. Dysfunction in this mode of control is thought to compromise their motor learning capa

  3. Cross-cultural compromises, multiculturalism and the actuality of unzipped Hofstede

    NARCIS (Netherlands)

    S.J. Magala (Slawomir)


    textabstractCultural background of identities calls for upholding of values, but realities of multicultural interactions require cross-cultural compromises. Compromises begin already with the introduction of the term multiculturalism, which served both as a platform for cross-cultural urban policies

  4. 7 CFR 1956.68 - Compromise or adjustment without debtor's signature. (United States)


    ... 7 Agriculture 14 2010-01-01 2009-01-01 true Compromise or adjustment without debtor's signature... Loan Programs and Multi-Family Housing § 1956.68 Compromise or adjustment without debtor's signature... made to obtain the debtor's signature and the date(s) of such effort. (c) The specific reasons why...

  5. The Potato Tuber Mitochondrial Proteome

    DEFF Research Database (Denmark)

    Salvato, Fernanda; Havelund, Jesper F; Chen, Mingjie;


    manner using normalized spectral counts including as many as 5-fold more “extreme” proteins (low mass, high isoelectric point, hydrophobic) than previous mitochondrial proteome studies. We estimate that this compendium of proteins represents a high coverage of the potato tuber mitochondrial proteome...... that more than 50% of the identified proteins harbor at least one modification. The most prominently observed class of posttranslational modifications was oxidative modifications. This study reveals approximately 500 new or previously unconfirmed plant mitochondrial proteins and outlines a facile strategy...... for unbiased, near-comprehensive identification of mitochondrial proteins and their modified forms....

  6. Maternal diet-induced obesity alters mitochondrial activity and redox status in mouse oocytes and zygotes.

    Directory of Open Access Journals (Sweden)

    Natalia Igosheva

    Full Text Available The negative impact of obesity on reproductive success is well documented but the stages at which development of the conceptus is compromised and the mechanisms responsible for the developmental failure still remain unclear. Recent findings suggest that mitochondria may be a contributing factor. However to date no studies have directly addressed the consequences of maternal obesity on mitochondria in early embryogenesis.Using an established murine model of maternal diet induced obesity and a live cell dynamic fluorescence imaging techniques coupled with molecular biology we have investigated the underlying mechanisms of obesity-induced reduced fertility. Our study is the first to show that maternal obesity prior to conception is associated with altered mitochondria in mouse oocytes and zygotes. Specifically, maternal diet-induced obesity in mice led to an increase in mitochondrial potential, mitochondrial DNA content and biogenesis. Generation of reactive oxygen species (ROS was raised while glutathione was depleted and the redox state became more oxidised, suggestive of oxidative stress. These altered mitochondrial properties were associated with significant developmental impairment as shown by the increased number of obese mothers who failed to support blastocyst formation compared to lean dams. We propose that compromised oocyte and early embryo mitochondrial metabolism, resulting from excessive nutrient exposure prior to and during conception, may underlie poor reproductive outcomes frequently reported in obese women.

  7. Mitochondrial cholesterol accumulation in alcoholic liver disease: Role of ASMase and endoplasmic reticulum stress. (United States)

    Marí, Montserrat; Morales, Albert; Colell, Anna; García-Ruiz, Carmen; Fernández-Checa, Jose C


    Alcoholic liver disease (ALD) is a major cause of chronic liver disease and a growing health concern in theworld. While the pathogenesis of ALD is poorly characterized key players identified in experimental models and patients, such as perturbations in mitochondrial structure and function, selective loss of antioxidant defense and susceptibility to inflammatory cytokines, contribute to ALD progression. Both oxidative stress and mitochondrial dysfunction compromise essential cellular functions and energy generation and hence are important pathogenic mechanisms of ALD. An important process mediating the mitochondrial disruption induced by alcohol intake is the trafficking of cholesterol to mitochondria, mediated by acid sphingomyelinase-induced endoplasmic reticulum stress, which contributes to increased cholesterol synthesis and StARD1upregulation. Mitochondrial cholesterol accumulation not only sensitizes to oxidative stress but it can contribute to the metabolic reprogramming in ALD, manifested by activation of the hypoxia inducible transcription factor 1 and stimulation of glycolysis and lactate secretion. Thus, a better understanding of the mechanisms underlying alcohol-mediated mitochondrial impairment and oxidative stress may lead to the identification of novel treatments for ALD. The present review briefly summarizes current knowledge on the cellular and molecular mechanisms contributing to alcohol-induced mitochondrial dysfunction and cholesterol accumulation and provides insights for potential therapeutic targets in ALD.

  8. Hydroxytyrosol ameliorates oxidative stress and mitochondrial dysfunction in doxorubicin-induced cardiotoxicity in rats with breast cancer. (United States)

    Granados-Principal, Sergio; El-Azem, Nuri; Pamplona, Reinald; Ramirez-Tortosa, Cesar; Pulido-Moran, Mario; Vera-Ramirez, Laura; Quiles, Jose L; Sanchez-Rovira, Pedro; Naudí, Alba; Portero-Otin, Manuel; Perez-Lopez, Patricia; Ramirez-Tortosa, Mcarmen


    Oxidative stress is involved in several processes including cancer, aging and cardiovascular disease, and has been shown to potentiate the therapeutic effect of drugs such as doxorubicin. Doxorubicin causes significant cardiotoxicity characterized by marked increases in oxidative stress and mitochondrial dysfunction. Herein, we investigate whether doxorubicin-associated chronic cardiac toxicity can be ameliorated with the antioxidant hydroxytyrosol in rats with breast cancer. Thirty-six rats bearing breast tumors induced chemically were divided into 4 groups: control, hydroxytyrosol (0.5mg/kg, 5days/week), doxorubicin (1mg/kg/week), and doxorubicin plus hydroxytyrosol. Cardiac disturbances at the cellular and mitochondrial level, mitochondrial electron transport chain complexes I-IV and apoptosis-inducing factor, and oxidative stress markers have been analyzed. Hydroxytyrosol improved the cardiac disturbances enhanced by doxorubicin by significantly reducing the percentage of altered mitochondria and oxidative damage. These results suggest that hydroxytyrosol improve the mitochondrial electron transport chain. This study demonstrates that hydroxytyrosol protect rat heart damage provoked by doxorubicin decreasing oxidative damage and mitochondrial alterations.

  9. Cardiomyopathy induced by artificial cardiac pacing: myth or reality sustained by evidence?

    Directory of Open Access Journals (Sweden)

    Andrés Di Leoni Ferrari


    Full Text Available Implantable cardiac pacing systems are a safe and effective treatment for symptomatic irreversible bradycardia. Under the proper indications, cardiac pacing might bring significant clinical benefit. Evidences from literature state that the action of the artificial pacing system, mainly when the ventricular lead is located at the apex of the right ventricle, produces negative effects to cardiac structure (remodeling, dilatation and function (dissinchrony. Patients with previously compromised left ventricular function would benefit the least with conventional right ventricle apical pacing, and are exposed to the risk of developing higher incidence of morbidity and mortality for heart failure. However, after almost 6 decades of cardiac pacing, just a reduced portion of patients in general would develop these alterations. In this context, there are not completely clear some issues related to cardiac pacing and the development of this cardiomyopathy. Causality relationships among QRS widening with a left bundle branch block morphology, contractility alterations within the left ventricle, and certain substrates or clinical (previous systolic dysfunction, structural heart disease, time from implant or electrical conditions (QRS duration, percentage of ventricular stimulation are still subjecte of debate. This review analyses contemporary data regarding this new entity, and discusses alternatives of how to use cardiac pacing in this context, emphasizing cardiac resynchronization therapy.

  10. Recent advances in understanding cardiac contractility in health and disease. (United States)

    MacLeod, Ken T


    The aim of this review is to provide the reader with a synopsis of some of the emerging ideas and experimental findings in cardiac physiology and pathophysiology that were published in 2015. To provide context for the non-specialist, a brief summary of cardiac contraction and calcium (Ca) regulation in the heart in health and disease is provided. Thereafter, some recently published articles are introduced that indicate the current thinking on (1) the Ca regulatory pathways modulated by Ca/calmodulin-dependent protein kinase II, (2) the potential influences of nitrosylation by nitric oxide or S-nitrosated proteins, (3) newly observed effects of reactive oxygen species (ROS) on contraction and Ca regulation following myocardial infarction and a possible link with changes in mitochondrial Ca, and (4) the effects of some of these signaling pathways on late Na current and pro-arrhythmic afterdepolarizations as well as the effects of transverse tubule disturbances.

  11. Results of treatment of congenital coronary artery fistulae in combination with cardiac arrhythmias

    Directory of Open Access Journals (Sweden)

    Bockeria L.A.


    and quality of life. Coronary angiography and computed tomography are the main diagnostic methods allowing to examine CAF. Hemodynamically non-compromised CAF coincided with CA require a follow-up and, if necessary, surgical and/or medical therapy of CA. Main indications for embolization are proximal location and single CAF. Indications for surgical on-pump repair are concomitant cardiac pathology and relatively large and wide CAF.

  12. Carnitine palmitoyl transferase-I inhibition is not associated with cardiac hypertrophy in rats fed a high fat diet (United States)

    Cardiac lipotoxicity is characterized by hypertrophy and contractile dysfunction and can be triggered by impaired mitochondrial fatty acid oxidation and lipid accumulation. The present study investigated the effect of dietary fatty acid intake alone and in combination with inhibition of mitochondria...

  13. Nebivolol Ameliorates Cardiac NLRP3 Inflammasome Activation in a Juvenile-Adolescent Animal Model of Diet-Induced Obesity (United States)

    Xie, Qihai; Wei, Tong; Huang, Chenglin; Liu, Penghao; Sun, Mengwei; Shen, Weili; Gao, Pingjin


    NLRP3 is involved in obesity-induced cardiac remodeling and dysfunction. In this study, we evaluated whether the cardiac protective effects of nebivolol relied on attenuating NLRP3 activation in a juvenile-adolescent animal model of diet-induced obesity. Weaning male Sprague-Dawley rats were fed with either a standard chow diet (ND) or a high-fat diet (HFD) for 8 weeks. The obese rats were subsequently subdivided into three groups: 1) HFD control group; 2) HFD with low-dose nebivolol (5 mg/kg/d); 3) HFD with high-dose nebivolol (10 mg/kg/d). Treatment with nebivolol prevented HFD-induced obesity associated excess cardiac lipid accumulation as well as myocardial mitochondrial dysfunction. Nebivolol attenuated pro-inflammatory cytokines secretion and NLRP3 inflammasome activation in myocardium of obese rats. In parallel, nebivolol treatment of obese animals increased cardiac β3-AR expression, reversing the reduction of endothelial nitric oxide synthase (eNOS). In vitro, nebivolol treatment of palmitate-incubated H9C2 cells suppressed autophagy, restored mitochondrial biogenesis, leading to decreased mitochondrial reactive oxygen species (mtROS) generation, and suppressed NLRP3 inflammasome activation. Meanwhile the presence of shRNA against β3-AR or against eNOS deteriorated the protective effects of nebivolol. These data suggest the beneficial effect of nebivolol on myocardial lipotoxicity contributing to inhibiting NLRP3 inflammasome activation possibly via improved mitochondrial dysfunction. PMID:27686325

  14. Ozone protects rat heart against ischemia-reperfusion injury: A role for oxidative preconditioning in attenuating mitochondrial injury. (United States)

    Meng, Weixin; Xu, Ying; Li, Dandan; Zhu, Erjun; Deng, Li; Liu, Zonghong; Zhang, Guowei; Liu, Hongyu


    Ischemia-reperfusion injury (IRI) is a major cause of cardiac dysfunction during cardiovascular surgery, heart transplantation and cardiopulmonary bypass procedures. The purpose of the present study was to explore, firstly, whether ozone induces oxidative preconditioning by activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and, secondly, whether ozone oxidative preconditioning (OzoneOP) can protect the heart against IRI by attenuating mitochondrial damage. Rats were subjected to 30min of cardiac ischemia followed by 2h of reperfusion, with or without prior OzoneOP (100μg/kg/day) for 5 days. Antioxidant capacity, myocardial apoptosis and mitochondrial damage were evaluated and compared at the end of reperfusion. OzoneOP was found to increase antioxidant capacity and to protect the myocardium against IRI by attenuating mitochondrial damage and myocardial apoptosis. The study suggests a potential role for OzoneOP in protecting the heart against IRI during cardiovascular surgery, cardiopulmonary bypass procedures or transplantation.

  15. Inheritance of the yeast mitochondrial genome

    DEFF Research Database (Denmark)

    Piskur, Jure


    Mitochondrion, extrachromosomal genetics, intergenic sequences, genome size, mitochondrial DNA, petite mutation, yeast......Mitochondrion, extrachromosomal genetics, intergenic sequences, genome size, mitochondrial DNA, petite mutation, yeast...

  16. Sealing the mitochondrial respirasome. (United States)

    Winge, Dennis R


    The mitochondrial respiratory chain is organized within an array of supercomplexes that function to minimize the generation of reactive oxygen species (ROS) during electron transfer reactions. Structural models of supercomplexes are now known. Another recent advance is the discovery of non-OXPHOS complex proteins that appear to adhere to and seal the individual respiratory complexes to form stable assemblages that prevent electron leakage. This review highlights recent advances in our understanding of the structures of supercomplexes and the factors that mediate their stability.

  17. Cardiac fusion and complex congenital cardiac defects in thoracopagus twins: diagnostic value of cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of); Park, Jeong-Jun [University of Ulsan College of Medicine, Asan Medical Center, Department of Pediatric Cardiac Surgery, Seoul (Korea, Republic of); Kim, Ellen Ai-Rhan [University of Ulsan College of Medicine, Asan Medical Center, Division of Neonatology, Department of Pediatrics, Seoul (Korea, Republic of); Won, Hye-Sung [University of Ulsan College of Medicine, Asan Medical Center, Department of Obstetrics and Gynecology, Seoul (Korea, Republic of)


    Most thoracopagus twins present with cardiac fusion and associated congenital cardiac defects, and assessment of this anatomy is of critical importance in determining patient care and outcome. Cardiac CT with electrocardiographic triggering provides an accurate and quick morphological assessment of both intracardiac and extracardiac structures in newborns, making it the best imaging modality to assess thoracopagus twins during the neonatal period. In this case report, we highlight the diagnostic value of cardiac CT in thoracopagus twins with an interatrial channel and complex congenital cardiac defects. (orig.)

  18. The marine toxin, Yessotoxin, induces apoptosis and increases mitochondrial activity

    Directory of Open Access Journals (Sweden)

    Andrea Fernandez-Araujo


    Discussion: Colorimetric MTT assay is widely used as a viability measurement method (McHale and L., 1988;Chiba et al., 1998. But after YTX treatment, MTT assay had shown problems to detect a cell viability decrease. In this sense, in primary cardiac cell cultures, a false increment of the proliferation rate opposite to Sulforhodamine B assay (SRB results was reported after YTX treatment (Dell'Ovo et al., 2008. Also the same effect was obtained in different cancer cell lines after assaying anticancer therapies (Ulukaya et al., 2004. In our study, an increase in cell viability using MTT was observed when the number of cells was high, while by using the LDH assay a significant viability decrease was measured. In these conditions, YTX is activating extrinsic apoptosis cell death by increasing caspase 8 activity and caspase 3 levels. The explanation for this increase was found when the mitochondrial activity was quantified cell by cell in a cytometer. In these conditions a significant increment of mitochondrial activity was detected. Since the cell population is too high, the increase in mitochondrial activity that detects the MTT test disguised the decrease of signal due to the cell death and point to a false proliferation increase. In this sense, a mitochondrial activity decrease was observed after 48 hours YTX treatment in BE(2-M17 neuroblastoma cell line (Leira et al., 2002. However, this study was done in a microplate reader with a small number of cells (Leira et al., 2002. Therefore, to measure the viability by MTT assay is very important to take into account the number of cells per condition when the experiment is designed. Alternative assays, such as LDH test, independently of the direct mitochondrial activity, can be used.

  19. Molecular Genetics of Mitochondrial Disorders (United States)

    Wong, Lee-Jun C.


    Mitochondrial respiratory chain (RC) disorders (RCDs) are a group of genetically and clinically heterogeneous diseases because of the fact that protein components of the RC are encoded by both mitochondrial and nuclear genomes and are essential in all cells. In addition, the biogenesis, structure, and function of mitochondria, including DNA…

  20. Redox Homeostasis and Mitochondrial Dynamics

    NARCIS (Netherlands)

    Willems, P.H.G.M.; Rossignol, R.; Dieteren, C.E.J.; Murphy, M.P.; Koopman, W.J.H.


    Within living cells, mitochondria are considered relevant sources of reactive oxygen species (ROS) and are exposed to reactive nitrogen species (RNS). During the last decade, accumulating evidence suggests that mitochondrial (dys)function, ROS/RNS levels, and aberrations in mitochondrial morphology

  1. Mitochondrial disorders and the eye

    Directory of Open Access Journals (Sweden)

    O’Neill EC


    Full Text Available Nicole J Van Bergen, Rahul Chakrabarti, Evelyn C O'Neill, Jonathan G Crowston, Ian A TrounceCentre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Victoria, AustraliaAbstract: The clinical significance of disturbed mitochondrial function in the eye has emerged since mitochondrial DNA (mtDNA mutation was described in Leber's hereditary optic neuropathy. The spectrum of mitochondrial dysfunction has become apparent through increased understanding of the contribution of nuclear and somatic mtDNA mutations to mitochondrial dynamics and function. Common ophthalmic manifestations of mitochondrial dysfunction include optic atrophy, pigmentary retinopathy, and ophthalmoplegia. The majority of patients with ocular manifestations of mitochondrial disease also have variable central and peripheral nervous system involvement. Mitochondrial dysfunction has recently been associated with age-related retinal disease including macular degeneration and glaucoma. Therefore, therapeutic targets directed at promoting mitochondrial biogenesis and function offer a potential to both preserve retinal function and attenuate neurodegenerative processes.Keywords: mitochondria, disease, retina, eye, aging, neuroprotection

  2. Cardiac nuclear medicine

    Energy Technology Data Exchange (ETDEWEB)

    Gerson, M.C.


    The book begins with a review of the radionuclide methods available for evaluating cardiac perfusion and function. The authors discuss planar and tomographic thallium myocardial imaging, first-pass and equilibrium radionuclide angiography, and imaging with infarct-avid tracers. Several common but more specialized procedures are then reviewed: nonogemetric measurement of left ventricular volume, phase (Fourier) analysis, stroke volume ratio, right ventricular function, and diastolic function. A separate chapter is devoted to drug interventions and in particular the use of radionuclide ventriculography to monitor doxorubicin toxicity and therapy of congestive heart failure. The subsequent chapters provide a comprehensive guide to test selection, accuracy, and results in acute myocardial infarction, in postmyocardial infarction, in chronic coronary artery disease, before and after medical or surgical revascularization, in valvular heart disease, in cardiomyopathies, and in cardiac trauma.

  3. Sudden Cardiac Death

    Directory of Open Access Journals (Sweden)

    Yipsy María Gutiérrez Báez


    Full Text Available Since the second half of the twentieth century, dying suddenly due to heart-related problems has become the main health issue in all countries where infectious diseases are not prevalent. Sudden death from cardiac causes is an important global health problem. Major databases were searched for the leading causes of sudden cardiac death. It has been demonstrated that there is a group of hereditary diseases with structural alterations or without apparent organic cause that explains many cases of sudden death in young people, whether related or not to physical exertion. Certain population groups are at higher risk for this disease. They are relatively easy to identify and can be the target of primary prevention measures.

  4. Cardiac arrhythmias in pregnancy. (United States)

    Knotts, Robert J; Garan, Hasan


    As more women with repaired congenital heart disease survive to their reproductive years and many other women are delaying pregnancy until later in life, a rising concern is the risk of cardiac arrhythmias during pregnancy. Naturally occurring cardiovascular changes during pregnancy increase the likelihood that a recurrence of a previously experienced cardiac arrhythmia or a de novo arrhythmia will occur. Arrhythmias should be thoroughly investigated to determine if there is a reversible etiology, and risks/benefits of treatment options should be fully explored. We discuss the approach to working up and treating various arrhythmias during pregnancy with attention to fetal and maternal risks as well as treatment of fetal arrhythmias. Acute management in stable patients includes close monitoring and intravenous pharmacologic therapy, while DC cardioversion should be used to terminate arrhythmias in hemodynamically unstable patients. Long-term management may require continued oral antiarrhythmic therapy, with particular attention to fetal safety, to prevent complications associated with arrhythmias.

  5. Mitochondrial Dysfunction in Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    P. C. Keane


    Full Text Available Parkinson's disease (PD is a progressive, neurodegenerative condition that has increasingly been linked with mitochondrial dysfunction and inhibition of the electron transport chain. This inhibition leads to the generation of reactive oxygen species and depletion of cellular energy levels, which can consequently cause cellular damage and death mediated by oxidative stress and excitotoxicity. A number of genes that have been shown to have links with inherited forms of PD encode mitochondrial proteins or proteins implicated in mitochondrial dysfunction, supporting the central involvement of mitochondria in PD. This involvement is corroborated by reports that environmental toxins that inhibit the mitochondrial respiratory chain have been shown to be associated with PD. This paper aims to illustrate the considerable body of evidence linking mitochondrial dysfunction with neuronal cell death in the substantia nigra pars compacta (SNpc of PD patients and to highlight the important need for further research in this area.

  6. Muscle regeneration in mitochondrial myopathies

    DEFF Research Database (Denmark)

    Krag, T O; Hauerslev, S; Jeppesen, T D;


    Mitochondrial myopathies cover a diverse group of disorders in which ragged red and COX-negative fibers are common findings on muscle morphology. In contrast, muscle degeneration and regeneration, typically found in muscular dystrophies, are not considered characteristic features of mitochondrial...... myopathies. We investigated regeneration in muscle biopsies from 61 genetically well-defined patients affected by mitochondrial myopathy. Our results show that the perturbed energy metabolism in mitochondrial myopathies causes ongoing muscle regeneration in a majority of patients, and some were even affected...... by a dystrophic morphology. The results add to the complexity of the pathogenesis underlying mitochondrial myopathies, and expand the knowledge about the impact of energy deficiency on another aspect of muscle structure and function....

  7. Mitochondrial dynamics and peripheral neuropathy. (United States)

    Baloh, Robert H


    Peripheral neuropathy is perhaps the archetypal disease of axonal degeneration, characteristically involving degeneration of the longest axons in the body. Evidence from both inherited and acquired forms of peripheral neuropathy strongly supports that the primary pathology is in the axons themselves and points to disruption of axonal transport as an important disease mechanism. Recent studies in human genetics have further identified abnormalities in mitochondrial dynamics--the fusion, fission, and movement of mitochondria--as a player in the pathogenesis of inherited peripheral neuropathy. This review provides an update on the mechanisms of mitochondrial trafficking in axons and the emerging relationship between the disruption of mitochondrial dynamics and axonal degeneration. Evidence suggests mitochondria are a "critical cargo" whose transport is necessary for proper axonal and synaptic function. Importantly, understanding the regulation of mitochondrial movement and the consequences of decreased axonal mitochondrial function may define new paths for therapeutic agents in peripheral neuropathy and other neurodegenerative diseases.

  8. Endocrine disorders in mitochondrial disease. (United States)

    Schaefer, Andrew M; Walker, Mark; Turnbull, Douglass M; Taylor, Robert W


    Endocrine dysfunction in mitochondrial disease is commonplace, but predominantly restricted to disease of the endocrine pancreas resulting in diabetes mellitus. Other endocrine manifestations occur, but are relatively rare by comparison. In mitochondrial disease, neuromuscular symptoms often dominate the clinical phenotype, but it is of paramount importance to appreciate the multi-system nature of the disease, of which endocrine dysfunction may be a part. The numerous phenotypes attributable to pathogenic mutations in both the mitochondrial (mtDNA) and nuclear DNA creates a complex and heterogeneous catalogue of disease which can be difficult to navigate for novices and experts alike. In this article we provide an overview of the endocrine disorders associated with mitochondrial disease, the way in which the underlying mitochondrial disorder influences the clinical presentation, and how these factors influence subsequent management.

  9. Mitochondrial dysfunction bridges negative affective disorders and cardiomyopathy in socially isolated rats: Pros and cons of fluoxetine. (United States)

    Sonei, Nazanin; Amiri, Shayan; Jafarian, Iman; Anoush, Mahdieh; Rahimi-Balaei, Maryam; Bergen, Hugo; Haj-Mirzaian, Arya; Hosseini, Mir-Jamal


    Objectives Depression is tightly associated with cardiovascular comorbidity and accounts for high financial and social burden worldwide. Mitochondrial dysfunction contributes to the pathophysiology of depression and cardiovascular disorders; its contribution to depression-cardiovascular comorbidity has not yet been investigated. Methods Adolescent rats were subjected to 4 weeks of isolation (social isolation stress or SIS) or social conditions (control), and then they were divided into treatment (fluoxetine, 7.5 mg/kg/day for 21 days) and non-treatment groups. After different housing conditions and treatment, animals were evaluated by behavioural tests (n = 6-8) and mitochondrial assessments (n = 3) of brain and cardiac tissues. Results We found that juvenile SIS induced behavioural abnormalities and mitochondrial dysfunction in adulthood. We showed that juvenile SIS was associated with impaired respiratory chain complex, which leads to reactive oxygen species formation, oxidative damage and ATP abatement in both brain and heart. Administration of FLX (7.5 mg/kg/day) during the isolation period attenuated the effects of SIS on the brain mitochondria and behavioural abnormalities, but had little or no effect on SIS-induced mitochondrial dysfunction in cardiac tissue. Conclusions This suggests that juvenile SIS predisposes the co-occurrence of depression and cardiovascular disease through mitochondrial dysfunction and that therapeutic effect of fluoxetine is partly mediated by its effect on mitochondrial function.

  10. New Insights into the Role of Mitochondrial Dynamics and Autophagy during Oxidative Stress and Aging in the Heart

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Ikeda


    Full Text Available The heart is highly sensitive to the aging process. In the elderly, the heart tends to become hypertrophic and fibrotic. Stiffness increases with ensuing systolic and diastolic dysfunction. Aging also affects the cardiac response to stress. At the molecular level, the aging process is associated with accumulation of damaged proteins and organelles, partially due to defects in protein quality control systems. The accumulation of dysfunctional and abnormal mitochondria is an important pathophysiological feature of the aging process, which is associated with excessive production of reactive oxygen species. Mitochondrial fusion and fission and mitochondrial autophagy are crucial mechanisms for maintaining mitochondrial function and preserving energy production. In particular, mitochondrial fission allows for selective segregation of damaged mitochondria, which are afterward eliminated by autophagy. Unfortunately, recent evidence indicates that mitochondrial dynamics and autophagy are progressively impaired over time, contributing to the aging process. This suggests that restoration of these mechanisms could delay organ senescence and prevent age-associated cardiac diseases. Here, we discuss the current understanding of the close relationship between mitochondrial dynamics, mitophagy, oxidative stress, and aging, with a particular focus on the heart.

  11. Inhibition of JNK aggravates the recovery of rat hearts after global ischemia: the role of mitochondrial JNK.

    Directory of Open Access Journals (Sweden)

    Sehwan Jang

    Full Text Available c-Jun N-terminal kinase (JNK, a stress-activated MAPK, is activated during cardiac ischemia-reperfusion (IR. The role of JNK inhibitors in cardioprotection against IR still remains controversial, in part, due to spill-over effects of non-specific inhibitors. In the present study, we sought to examine whether inhibition of JNK by SU3327, a specific JNK inhibitor that inhibits upstream JNK signaling rather than the kinase activity of JNK, improves cardiac function and reduces heart damage during IR. Hearts of male Sprague-Dawley rats perfused by Langendorff were subjected to 25 min of global ischemia followed by 30 min reperfusion in the presence or absence of SU3327. Cardiac function was monitored throughout the perfusion period. Myocardial damage was extrapolated from LDH activity in the coronary effluent. At the end of reperfusion, mitochondria were isolated and used to measure respiration rates and mitochondrial permeability transition pore opening. Protein analysis of mitochondria predictably revealed that SU3327 inhibited JNK phosphorylation. Although SU3327 significantly reduced cell damage during the first minutes of reperfusion, it did not improve cardiac function and, furthermore, reduced the mitochondrial respiratory control index. Interestingly, SU3327 activated the other stress-related MAPK, p38, and greatly increased its translocation to mitochondria. Mitochondrial P-JNK and P-p38 were co-immunoprecipitated with complex III of the electron transfer chain. Thus, JNK plays an essential role in cardiac signaling under both physiological and pathological conditions. Its inhibition by SU3327 during IR aggravates cardiac function. The detrimental effects of JNK inhibition are associated with reciprocal p38 activation and mitochondrial dysfunction.

  12. Cardiac surgery 2015 reviewed. (United States)

    Doenst, Torsten; Strüning, Constanze; Moschovas, Alexandros; Gonzalez-Lopez, David; Essa, Yasin; Kirov, Hristo; Diab, Mahmoud; Faerber, Gloria


    For the year 2015, almost 19,000 published references can be found in PubMed when entering the search term "cardiac surgery". The last year has been again characterized by lively discussions in the fields where classic cardiac surgery and modern interventional techniques overlap. Lacking evidence in the field of coronary revascularization with either percutaneous coronary intervention or bypass surgery has been added. As in the years before, CABG remains the gold standard for the revascularization of complex stable triple-vessel disease. Plenty of new information has been presented comparing the conventional to transcatheter aortic valve implantation (TAVI) demonstrating similar short- and mid-term outcomes at high and low risk, but even a survival advantage with transfemoral TAVI at intermediate risk. In addition, there were many relevant and interesting other contributions from the purely operative arena. This review article will summarize the most pertinent publications in the fields of coronary revascularization, surgical treatment of valve disease, heart failure (i.e., transplantation and ventricular assist devices), and aortic surgery. While the article does not have the expectation of being complete and cannot be free of individual interpretation, it provides a condensed summary that is intended to give the reader "solid ground" for up-to-date decision-making in cardiac surgery.

  13. Cardiac hybrid imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gaemperli, Oliver [University Hospital Zurich, Cardiac Imaging, Zurich (Switzerland); University Hospital Zurich, Nuclear Cardiology, Cardiovascular Center, Zurich (Switzerland); Kaufmann, Philipp A. [University Hospital Zurich, Cardiac Imaging, Zurich (Switzerland); Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland)


    Hybrid cardiac single photon emission computed tomography (SPECT)/CT imaging allows combined assessment of anatomical and functional aspects of cardiac disease. In coronary artery disease (CAD), hybrid SPECT/CT imaging allows detection of coronary artery stenosis and myocardial perfusion abnormalities. The clinical value of hybrid imaging has been documented in several subsets of patients. In selected groups of patients, hybrid imaging improves the diagnostic accuracy to detect CAD compared to the single imaging techniques. Additionally, this approach facilitates functional interrogation of coronary stenoses and guidance with regard to revascularization procedures. Moreover, the anatomical information obtained from CT coronary angiography or coronary artery calcium scores (CACS) adds prognostic information over perfusion data from SPECT. The use of cardiac hybrid imaging has been favoured by the dissemination of dedicated hybrid systems and the release of dedicated image fusion software, which allow simple patient throughput for hybrid SPECT/CT studies. Further technological improvements such as more efficient detector technology to allow for low-radiation protocols, ultra-fast image acquisition and improved low-noise image reconstruction algorithms will be instrumental to further promote hybrid SPECT/CT in research and clinical practice. (orig.)

  14. Cardiac tissue engineering

    Directory of Open Access Journals (Sweden)



    Full Text Available We hypothesized that clinically sized (1-5 mm thick,compact cardiac constructs containing physiologically high density of viable cells (~108 cells/cm3 can be engineered in vitro by using biomimetic culture systems capable of providing oxygen transport and electrical stimulation, designed to mimic those in native heart. This hypothesis was tested by culturing rat heart cells on polymer scaffolds, either with perfusion of culture medium (physiologic interstitial velocity, supplementation of perfluorocarbons, or with electrical stimulation (continuous application of biphasic pulses, 2 ms, 5 V, 1 Hz. Tissue constructs cultured without perfusion or electrical stimulation served as controls. Medium perfusion and addition of perfluorocarbons resulted in compact, thick constructs containing physiologic density of viable, electromechanically coupled cells, in contrast to control constructs which had only a ~100 mm thick peripheral region with functionally connected cells. Electrical stimulation of cultured constructs resulted in markedly improved contractile properties, increased amounts of cardiac proteins, and remarkably well developed ultrastructure (similar to that of native heart as compared to non-stimulated controls. We discuss here the state of the art of cardiac tissue engineering, in light of the biomimetic approach that reproduces in vitro some of the conditions present during normal tissue development.

  15. Mitochondrial translocation of Nur77 induced by ROS contributed to cardiomyocyte apoptosis in metabolic syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Aibin; Liu, Jingyi [Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi’an (China); Institute of Cardiovascular Disease, General Hospital of Beijing Command, PLA, Beijing (China); Liu, Peilin; Jia, Min; Wang, Han [Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi’an (China); Tao, Ling, E-mail: [Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi’an (China)


    Highlights: • Metabolic syndrome exacerbated MI/R induced injury accompanied by decreased Nur77. • ROS led to Nur77 translocation in metabolic syndrome. • Inhibiting relocation of Nur77 to mitochondria reduced ROS-induced cardiomyocyte injury in metabolic syndrome. - Abstract: Metabolic syndrome is a major risk factor for cardiovascular diseases, and increased cardiomyocyte apoptosis which contributes to cardiac dysfunction after myocardial ischemia/reperfusion (MI/R) injury. Nur77, a nuclear orphan receptor, is involved in such various cellular events as apoptosis, proliferation, and glucose and lipid metabolism in several cell types. Apoptosis is positively correlated with mitochondrial translocation of Nur77 in the cancer cells. However, the roles of Nur77 on cardiac myocytes in patients with metabolic syndrome remain unclear. The objective of this study was to determine whether Nur77 may contribute to cardiac apoptosis in patients with metabolic syndrome after I/R injury, and, if so, to identify the underlying molecular mechanisms responsible. We used leptin-deficient (ob/ob) mice to make metabolic syndrome models. In this report, we observed that, accompanied by the substantial decline in apoptosis inducer Nur77, MI/R induced cardiac dysfunction was manifested as cardiomyopathy and increased ROS. Using the neonatal rat cardiac myocytes cultured in a high-glucose and high-fat medium, we found that excessive H{sub 2}O{sub 2} led to the significant alteration in mitochondrial membrane potential and translocation of Nur77 from the nucleus to the mitochondria. However, inhibition of the relocation of Nur77 to mitochondria via Cyclosporin A reversed the changes in membrane potential mediated by H{sub 2}O{sub 2} and reduced myocardial cell injury. Therefore, these data provide a potential underlying mechanism for cardiac dysfunction in metabolic syndrome and the suppression of Nur77 translocation may provide an effective approach to reduce cardiac injury in the

  16. Mesenchymal stem cells transfer mitochondria to the cells with virtually no mitochondrial function but not with pathogenic mtDNA mutations. (United States)

    Cho, Young Min; Kim, Ju Han; Kim, Mingoo; Park, Su Jin; Koh, Sang Hyeok; Ahn, Hyo Seop; Kang, Gyeong Hoon; Lee, Jung-Bin; Park, Kyong Soo; Lee, Hong Kyu


    It has been reported that human mesenchymal stem cells (MSCs) can transfer mitochondria to the cells with severely compromised mitochondrial function. We tested whether the reported intercellular mitochondrial transfer could be replicated in different types of cells or under different experimental conditions, and tried to elucidate possible mechanism. Using biochemical selection methods, we found exponentially growing cells in restrictive media (uridine(-) and bromodeoxyuridine [BrdU](+)) during the coculture of MSCs (uridine-independent and BrdU-sensitive) and 143B-derived cells with severe mitochondrial dysfunction induced by either long-term ethidium bromide treatment or short-term rhodamine 6G (R6G) treatment (uridine-dependent but BrdU-resistant). The exponentially growing cells had nuclear DNA fingerprint patterns identical to 143B, and a sequence of mitochondrial DNA (mtDNA) identical to the MSCs. Since R6G causes rapid and irreversible damage to mitochondria without the removal of mtDNA, the mitochondrial function appears to be restored through a direct transfer of mitochondria rather than mtDNA alone. Conditioned media, which were prepared by treating mtDNA-less 143B ρ(0) cells under uridine-free condition, induced increased chemotaxis in MSC, which was also supported by transcriptome analysis. Cytochalasin B, an inhibitor of chemotaxis and cytoskeletal assembly, blocked mitochondrial transfer phenomenon in the above condition. However, we could not find any evidence of mitochondrial transfer to the cells harboring human pathogenic mtDNA mutations (A3243G mutation or 4,977 bp deletion). Thus, the mitochondrial transfer is limited to the condition of a near total absence of mitochondrial function. Elucidation of the mechanism of mitochondrial transfer will help us create a potential cell therapy-based mitochondrial restoration or mitochondrial gene therapy for human diseases caused by mitochondrial dysfunction.

  17. Mesenchymal stem cells transfer mitochondria to the cells with virtually no mitochondrial function but not with pathogenic mtDNA mutations.

    Directory of Open Access Journals (Sweden)

    Young Min Cho

    Full Text Available It has been reported that human mesenchymal stem cells (MSCs can transfer mitochondria to the cells with severely compromised mitochondrial function. We tested whether the reported intercellular mitochondrial transfer could be replicated in different types of cells or under different experimental conditions, and tried to elucidate possible mechanism. Using biochemical selection methods, we found exponentially growing cells in restrictive media (uridine(- and bromodeoxyuridine [BrdU](+ during the coculture of MSCs (uridine-independent and BrdU-sensitive and 143B-derived cells with severe mitochondrial dysfunction induced by either long-term ethidium bromide treatment or short-term rhodamine 6G (R6G treatment (uridine-dependent but BrdU-resistant. The exponentially growing cells had nuclear DNA fingerprint patterns identical to 143B, and a sequence of mitochondrial DNA (mtDNA identical to the MSCs. Since R6G causes rapid and irreversible damage to mitochondria without the removal of mtDNA, the mitochondrial function appears to be restored through a direct transfer of mitochondria rather than mtDNA alone. Conditioned media, which were prepared by treating mtDNA-less 143B ρ(0 cells under uridine-free condition, induced increased chemotaxis in MSC, which was also supported by transcriptome analysis. Cytochalasin B, an inhibitor of chemotaxis and cytoskeletal assembly, blocked mitochondrial transfer phenomenon in the above condition. However, we could not find any evidence of mitochondrial transfer to the cells harboring human pathogenic mtDNA mutations (A3243G mutation or 4,977 bp deletion. Thus, the mitochondrial transfer is limited to the condition of a near total absence of mitochondrial function. Elucidation of the mechanism of mitochondrial transfer will help us create a potential cell therapy-based mitochondrial restoration or mitochondrial gene therapy for human diseases caused by mitochondrial dysfunction.

  18. Co segregation of the m.1555A>G mutation in the MT-RNR1 gene and mutations in MT-ATP6 gene in a family with dilated mitochondrial cardiomyopathy and hearing loss: A whole mitochondrial genome screening. (United States)

    Alila-Fersi, Olfa; Chamkha, Imen; Majdoub, Imen; Gargouri, Lamia; Mkaouar-Rebai, Emna; Tabebi, Mouna; Tlili, Abdelaziz; Keskes, Leila; Mahfoudh, Abdelmajid; Fakhfakh, Faiza


    Mitochondrial disease refers to a heterogeneous group of disorders resulting in defective cellular energy production due to dysfunction of the mitochondrial respiratory chain, which is responsible for the generation of most cellular energy. Because cardiac muscles are one of the high energy demanding tissues, mitochondrial cardiomyopathies is one of the most frequent mitochondria disorders. Mitochondrial cardiomyopathy has been associated with several point mutations of mtDNA in both genes encoded mitochondrial proteins and mitochondrial tRNA and rRNA. We reported here the first description of mutations in MT-ATP6 gene in two patients with clinical features of dilated mitochondrial cardiomyopathy. The mutational analysis of the whole mitochondrial DNA revealed the presence of m.1555A>G mutation in MT-RNR1 gene associated to the m.8527A>G (p.M>V) and the m.8392C>T (p.136P>S) variations in the mitochondrial MT-ATP6 gene in patient1 and his family members with variable phenotype including hearing impairment. The second patient with isolated mitochondrial cardiomyopathy presented the m.8605C>T (p.27P>S) mutation in the MT-ATP6 gene. The three mutations p.M1V, p.P27S and p.P136S detected in MT-ATP6 affected well conserved residues of the mitochondrial protein ATPase 6. In addition, the substitution of proline residue at position 27 and 136 effect hydrophobicity and structure flexibility conformation of the protein.

  19. Yeast Mitochondrial Interactosome Model: Metabolon Membrane Proteins Complex Involved in the Channeling of ADP/ATP

    Directory of Open Access Journals (Sweden)

    Benjamin Clémençon


    Full Text Available The existence of a mitochondrial interactosome (MI has been currently well established in mammalian cells but the exact composition of this super-complex is not precisely known, and its organization seems to be different from that in yeast. One major difference is the absence of mitochondrial creatine kinase (MtCK in yeast, unlike that described in the organization model of MI, especially in cardiac, skeletal muscle and brain cells. The aim of this review is to provide a detailed description of different partner proteins involved in the synergistic ADP/ATP transport across the mitochondrial membranes in the yeast Saccharomyces cerevisiae and to propose a new mitochondrial interactosome model. The ADP/ATP (Aacp and inorganic phosphate (PiC carriers as well as the VDAC (or mitochondrial porin catalyze the import and export of ADP, ATP and Pi across the mitochondrial membranes. Aacp and PiC, which appear to be associated with the ATP synthase, consist of two nanomotors (F0, F1 under specific conditions and form ATP synthasome. Identification and characterization of such a complex were described for the first time by Pedersen and co-workers in 2003.

  20. Mitochondrial uncoupling does not decrease reactive oxygen species production after ischemia-reperfusion. (United States)

    Quarrie, Ricardo; Lee, Daniel S; Reyes, Levy; Erdahl, Warren; Pfeiffer, Douglas R; Zweier, Jay L; Crestanello, Juan A


    Cardiac ischemia-reperfusion (IR) leads to myocardial dysfunction by increasing production of reactive oxygen species (ROS). Mitochondrial H(+) leak decreases ROS formation; it has been postulated that increasing H(+) leak may be a mechanism of decreasing ROS production after IR. Ischemic preconditioning (IPC) decreases ROS formation after IR, but the mechanism is unknown. We hypothesize that pharmacologically increasing mitochondrial H(+) leak would decrease ROS production after IR. We further hypothesize that IPC would be associated with an increase in the rate of H(+) leak. Isolated male Sprague-Dawley rat hearts were subjected to either control or IPC. Mitochondria were isolated at end equilibration, end ischemia, and end reperfusion. Mitochondrial membrane potential (mΔΨ) was measured using a tetraphenylphosphonium electrode. Mitochondrial uncoupling was achieved by adding increasing concentrations of FCCP. Mitochondrial ROS production was measured by fluorometry using Amplex-Red. Pyridine dinucleotide levels were measured using HPLC. Before IR, increasing H(+) leak decreased mitochondrial ROS production. After IR, ROS production was not affected by increasing H(+) leak. H(+) leak increased at end ischemia in control mitochondria. IPC mitochondria showed no change in the rate of H(+) leak throughout IR. NADPH levels decreased after IR in both IPC and control mitochondria while NADH increased. Pharmacologically, increasing H(+) leak is not a method of decreasing ROS production after IR. Replenishing the NADPH pool may be a means of scavenging the excess ROS thereby attenuating oxidative damage after IR.

  1. Indeterminacy of Spatiotemporal Cardiac Alternans

    CERN Document Server

    Zhao, Xiaopeng


    Cardiac alternans, a beat-to-beat alternation in action potential duration (at the cellular level) or in ECG morphology (at the whole heart level), is a marker of ventricular fibrillation, a fatal heart rhythm that kills hundreds of thousands of people in the US each year. Investigating cardiac alternans may lead to a better understanding of the mechanisms of cardiac arrhythmias and eventually better algorithms for the prediction and prevention of such dreadful diseases. In paced cardiac tissue, alternans develops under increasingly shorter pacing period. Existing experimental and theoretical studies adopt the assumption that alternans in homogeneous cardiac tissue is exclusively determined by the pacing period. In contrast, we find that, when calcium-driven alternans develops in cardiac fibers, it may take different spatiotemporal patterns depending on the pacing history. Because there coexist multiple alternans solutions for a given pacing period, the alternans pattern on a fiber becomes unpredictable. Usin...

  2. Protective effect of Boerhaavia diffusa L. against mitochondrial dysfunction in angiotensin II induced hypertrophy in H9c2 cardiomyoblast cells.

    Directory of Open Access Journals (Sweden)

    Ayyappan Prathapan

    Full Text Available Mitochondrial dysfunction plays a critical role in the development of cardiac hypertrophy and heart failure. So mitochondria are emerging as one of the important druggable targets in the management of cardiac hypertrophy and other associated complications. In the present study, effects of ethanolic extract of Boerhaavia diffusa (BDE, a green leafy vegetable against mitochondrial dysfunction in angiotensin II (Ang II induced hypertrophy in H9c2 cardiomyoblasts was evaluated. H9c2 cells challenged with Ang II exhibited pathological hypertrophic responses and mitochondrial dysfunction which was evident from increment in cell volume (49.09±1.13%, protein content (55.17±1.19%, LDH leakage (58.74±1.87%, increased intracellular ROS production (26.25±0.91%, mitochondrial superoxide generation (65.06±2.27%, alteration in mitochondrial transmembrane potential (ΔΨm, opening of mitochondrial permeability transition pore (mPTP and mitochondrial swelling. In addition, activities of mitochondrial respiratory chain complexes (I-IV, aconitase, NADPH oxidase, thioredoxin reductase, oxygen consumption rate and calcium homeostasis were evaluated. Treatment with BDE significantly prevented the generation of intracellular ROS and mitochondrial superoxide radicals and protected the mitochondria by preventing dissipation of ΔΨm, opening of mPTP, mitochondrial swelling and enhanced the activities of respiratory chain complexes and oxygen consumption rate in H9c2 cells. Activities of aconitase and thioredoxin reductase which was lowered (33.77±0.68% & 45.81±0.71% respectively due to hypertrophy, were increased in BDE treated cells (P≤0.05. Moreover, BDE also reduced the intracellular calcium overload in Ang II treated cells. Overall results revealed the protective effects of B. diffusa against mitochondrial dysfunction in hypertrophy in H9c2 cells and the present findings may shed new light on the therapeutic potential of B. diffusa in addition to its

  3. Are mitochondrial reactive oxygen species required for autophagy?

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Jianfei, E-mail: [Center for Free Radical and Antioxidant Health, Department of Environmental and Occupational Health, University of Pittsburgh (United States); Maeda, Akihiro; Ji, Jing [Center for Free Radical and Antioxidant Health, Department of Environmental and Occupational Health, University of Pittsburgh (United States); Baty, Catherine J.; Watkins, Simon C. [Center for Biologic Imaging, Department of Cell Biology and Physiology, University of Pittsburgh (United States); Greenberger, Joel S. [Department of Radiation Oncology, University of Pittsburgh (United States); Kagan, Valerian E., E-mail: [Center for Free Radical and Antioxidant Health, Department of Environmental and Occupational Health, University of Pittsburgh (United States)


    Highlights: {yields} Autophageal and apoptotic pathways were dissected in cytochrome c deficient cells. {yields} Staurosporine (STS)-induced autophagy was not accompanied by ROS generation. {yields} Autophagy was detectable in mitochondrial DNA deficient {rho}{sup 0} cells. {yields} Mitochondrial ROS are not required for the STS-induced autophagy in HeLa cells. -- Abstract: Reactive oxygen species (ROS) are said to participate in the autophagy signaling. Supporting evidence is obscured by interference of autophagy and apoptosis, whereby the latter heavily relies on ROS signaling. To dissect autophagy from apoptosis we knocked down expression of cytochrome c, the key component of mitochondria-dependent apoptosis, in HeLa cells using shRNA. In cytochrome c deficient HeLa1.2 cells, electron transport was compromised due to the lack of electron shuttle between mitochondrial respiratory complexes III and IV. A rapid and robust LC3-I/II conversion and mitochondria degradation were observed in HeLa1.2 cells treated with staurosporine (STS). Neither generation of superoxide nor accumulation of H{sub 2}O{sub 2} was detected in STS-treated HeLa1.2 cells. A membrane permeable antioxidant, PEG-SOD, plus catalase exerted no effect on STS-induced LC3-I/II conversion and mitochondria degradation. Further, STS caused autophagy in mitochondria DNA-deficient {rho}{sup o} HeLa1.2 cells in which both electron transport and ROS generation were completely disrupted. Counter to the widespread view, we conclude that mitochondrial ROS are not required for the induction of autophagy.

  4. Decreased Bioenergetic Health Index in monocytes isolated from the pericardial fluid and blood of post-operative cardiac surgery patients. (United States)

    Kramer, Philip A; Chacko, Balu K; George, David J; Zhi, Degui; Wei, Chih-Cheng; Dell'Italia, Louis J; Melby, Spencer J; George, James F; Darley-Usmar, Victor M


    Monitoring the bioenergetics of leucocytes is now emerging as an important approach in translational research to detect mitochondrial dysfunction in blood or other patient samples. Using the mitochondrial stress test, which involves the sequential addition of mitochondrial inhibitors to adherent leucocytes, we have calculated a single value, the Bioenergetic Health Index (BHI), which represents the mitochondrial function in cells isolated from patients. In the present report, we assess the BHI of monocytes isolated from the post-operative blood and post-operative pericardial fluid (PO-PCF) from patients undergoing cardiac surgery. Analysis of the bioenergetics of monocytes isolated from patients' PO-PCF revealed a profound decrease in mitochondrial function compared with monocytes isolated from their blood or from healthy controls. Further, patient blood monocytes showed no significant difference in the individual energetic parameters from the mitochondrial stress test but, when integrated into the BHI evaluation, there was a significant decrease in BHI compared with healthy control monocytes. These data support the utility of BHI measurements in integrating the individual parameters from the mitochondrial stress test into a single value. Supporting our previous finding that the PO-PCF is pro-oxidant, we found that exposure of rat cardiomyocytes to PO-PCF caused a significant loss of mitochondrial membrane potential and increased reactive oxygen species (ROS). These findings support the hypothesis that integrated measures of bioenergetic health could have prognostic and diagnostic value in translational bioenergetics.

  5. Redox regulation of mitochondrial biogenesis. (United States)

    Piantadosi, Claude A; Suliman, Hagir B


    The cell renews, adapts, or expands its mitochondrial population during episodes of cell damage or periods of intensified energy demand by the induction of mitochondrial biogenesis. This bigenomic program is modulated by redox-sensitive signals that respond to physiological nitric oxide (NO), carbon monoxide (CO), and mitochondrial reactive oxygen species production. This review summarizes our current ideas about the pathways involved in the activation of mitochondrial biogenesis by the physiological gases leading to changes in the redox milieu of the cell, with an emphasis on the responses to oxidative stress and inflammation. The cell's energy supply is protected from conditions that damage mitochondria by an inducible transcriptional program of mitochondrial biogenesis that operates in large part through redox signals involving the nitric oxide synthase and the heme oxygenase-1/CO systems. These redox events stimulate the coordinated activities of several multifunctional transcription factors and coactivators also involved in the elimination of defective mitochondria and the expression of counterinflammatory and antioxidant genes, such as IL10 and SOD2, as part of a unified damage-control network. The redox-regulated mechanisms of mitochondrial biogenesis schematically outlined in the graphical abstract link mitochondrial quality control to an enhanced capacity to support the cell's metabolic needs while improving its resistance to metabolic failure and avoidance of cell death during periods of oxidative stress.

  6. Role and Treatment of Mitochondrial DNA-Related Mitochondrial Dysfunction in Sporadic Neurodegenerative Diseases


    Swerdlow, Russell H.


    Several sporadic neurodegenerative diseases display phenomena that directly or indirectly relate to mitochondrial function. Data suggesting altered mitochondrial function in these diseases could arise from mitochondrial DNA (mtDNA) are reviewed. Approaches for manipulating mitochondrial function and minimizing the downstream consequences of mitochondrial dysfunction are discussed.

  7. Case Report: Penetrating Cardiac Injury

    Directory of Open Access Journals (Sweden)

    Adem Grbolar


    Full Text Available Summary: Penetrating cardiac injurys caused by gunshots and penetrating tools have high mortality rates. The way of injury, how the cardiac area is effected and the presence of cardiac tamponadecauses mortality in different rates. However the better treatment quality of hospitals, increasingoperative techniques, and internel care unit quality has not been change during the years. Searching the literature, we want to present a 42 years old male patient whowas injured by knife and had a 1 cm skin wound on chest with cardiac tamponade. After sternotomy a 7 cm laseration was observed in heart. Cardioraphy was performed.

  8. Cardiac surgery for Kartagener syndrome. (United States)

    Tkebuchava, T; von Segesser, L K; Niederhäuser, U; Bauersfeld, U; Turina, M


    Two patients (one girl, one boy) with Kartagener syndrome (situs inversus, bronchiectasis, sinusitis), despite pulmonary problems and associated congenital cardiac anomalies, were operated on at the ages of 4 years and 7 years, respectively. They had had previous palliative treatment at the age of 3 months and 1.3 years, respectively. Both postoperative periods after total correction were without significant complications. Long-term follow-up was available for 9 and 19 years, respectively, with no manifestations of heart insufficiency. Both patients are physically active, and neither requires cardiac medication. Patients with Kartagener syndrome and associated congenital cardiac anomalies can successfully undergo multiple cardiac operations with good long-term outcome.

  9. Mitochondrial dysfunction in myofibrillar myopathy. (United States)

    Vincent, Amy E; Grady, John P; Rocha, Mariana C; Alston, Charlotte L; Rygiel, Karolina A; Barresi, Rita; Taylor, Robert W; Turnbull, Doug M


    Myofibrillar myopathies (MFM) are characterised by focal myofibrillar destruction and accumulation of myofibrillar elements as protein aggregates. They are caused by mutations in the DES, MYOT, CRYAB, FLNC, BAG3, DNAJB6 and ZASP genes as well as other as yet unidentified genes. Previous studies have reported changes in mitochondrial morphology and cellular positioning, as well as clonally-expanded, large-scale mitochondrial DNA (mtDNA) deletions and focal respiratory chain deficiency in muscle of MFM patients. Here we examine skeletal muscle from patients with desmin (n = 6), ZASP (n = 1) and myotilin (n = 2) mutations and MFM protein aggregates, to understand how mitochondrial dysfunction may contribute to the underlying mechanisms causing disease pathology. We have used a validated quantitative immunofluorescent assay to study respiratory chain protein levels, together with oxidative enzyme histochemistry and single cell mitochondrial DNA analysis, to examine mitochondrial changes. Results demonstrate a small number of clonally-expanded mitochondrial DNA deletions, which we conclude are due to both ageing and disease pathology. Further to this we report higher levels of respiratory chain complex I and IV deficiency compared to age matched controls, although overall levels of respiratory deficient muscle fibres in patient biopsies are low. More strikingly, a significantly higher percentage of myofibrillar myopathy patient muscle fibres have a low mitochondrial mass compared to controls. We concluded this is mechanistically unrelated to desmin and myotilin protein aggregates; however, correlation between mitochondrial mass and muscle fibre area is found. We suggest this may be due to reduced mitochondrial biogenesis in combination with muscle fibre hypertrophy.

  10. Private mitochondrial DNA variants in danish patients with hypertrophic cardiomyopathy.

    Directory of Open Access Journals (Sweden)

    Christian M Hagen

    Full Text Available Hypertrophic cardiomyopathy (HCM is a genetic cardiac disease primarily caused by mutations in genes coding for sarcomeric proteins. A molecular-genetic etiology can be established in ~60% of cases. Evolutionarily conserved mitochondrial DNA (mtDNA haplogroups are susceptibility factors for HCM. Several polymorphic mtDNA variants are associated with a variety of late-onset degenerative diseases and affect mitochondrial function. We examined the role of private, non-haplogroup associated, mitochondrial variants in the etiology of HCM. In 87 Danish HCM patients, full mtDNA sequencing revealed 446 variants. After elimination of 312 (69.9% non-coding and synonymous variants, a further 109 (24.4% with a global prevalence > 0.1%, three (0.7% haplogroup associated and 19 (2.0% variants with a low predicted in silico likelihood of pathogenicity, three variants: MT-TC: m.5772G>A, MT-TF: m.644A>G, and MT-CYB: m.15024G>A, p.C93Y remained. A detailed analysis of these variants indicated that none of them are likely to cause HCM. In conclusion, private mtDNA mutations are frequent, but they are rarely, if ever, associated with HCM.

  11. Combating QR-Code-Based Compromised Accounts in Mobile Social Networks

    Directory of Open Access Journals (Sweden)

    Dong Guo


    Full Text Available Cyber Physical Social Sensing makes mobile social networks (MSNs popular with users. However, such attacks are rampant as malicious URLs are spread covertly through quick response (QR codes to control compromised accounts in MSNs to propagate malicious messages. Currently, there are generally two types of methods to identify compromised accounts in MSNs: one type is to analyze the potential threats on wireless access points and the potential threats on handheld devices’ operation systems so as to stop compromised accounts from spreading malicious messages; the other type is to apply the method of detecting compromised accounts in online social networks to MSNs. The above types of methods above focus neither on the problems of MSNs themselves nor on the interaction of sensors’ messages, which leads to the restrictiveness of platforms and the simplification of methods. In order to stop the spreading of compromised accounts in MSNs effectively, the attacks have to be traced to their sources first. Through sensors, users exchange information in MSNs and acquire information by scanning QR codes. Therefore, analyzing the traces of sensor-related information helps to identify the compromised accounts in MSNs. This paper analyzes the diversity of information sending modes of compromised accounts and normal accounts, analyzes the regularity of GPS (Global Positioning System-based location information, and introduces the concepts of entropy and conditional entropy so as to construct an entropy-based model based on machine learning strategies. To achieve the goal, about 500,000 accounts of Sina Weibo and about 100 million corresponding messages are collected. Through the validation, the accuracy rate of the model is proved to be as high as 87.6%, and the false positive rate is only 3.7%. Meanwhile, the comparative experiments of the feature sets prove that sensor-based location information can be applied to detect the compromised accounts in MSNs.

  12. Combating QR-Code-Based Compromised Accounts in Mobile Social Networks. (United States)

    Guo, Dong; Cao, Jian; Wang, Xiaoqi; Fu, Qiang; Li, Qiang


    Cyber Physical Social Sensing makes mobile social networks (MSNs) popular with users. However, such attacks are rampant as malicious URLs are spread covertly through quick response (QR) codes to control compromised accounts in MSNs to propagate malicious messages. Currently, there are generally two types of methods to identify compromised accounts in MSNs: one type is to analyze the potential threats on wireless access points and the potential threats on handheld devices' operation systems so as to stop compromised accounts from spreading malicious messages; the other type is to apply the method of detecting compromised accounts in online social networks to MSNs. The above types of methods above focus neither on the problems of MSNs themselves nor on the interaction of sensors' messages, which leads to the restrictiveness of platforms and the simplification of methods. In order to stop the spreading of compromised accounts in MSNs effectively, the attacks have to be traced to their sources first. Through sensors, users exchange information in MSNs and acquire information by scanning QR codes. Therefore, analyzing the traces of sensor-related information helps to identify the compromised accounts in MSNs. This paper analyzes the diversity of information sending modes of compromised accounts and normal accounts, analyzes the regularity of GPS (Global Positioning System)-based location information, and introduces the concepts of entropy and conditional entropy so as to construct an entropy-based model based on machine learning strategies. To achieve the goal, about 500,000 accounts of Sina Weibo and about 100 million corresponding messages are collected. Through the validation, the accuracy rate of the model is proved to be as high as 87.6%, and the false positive rate is only 3.7%. Meanwhile, the comparative experiments of the feature sets prove that sensor-based location information can be applied to detect the compromised accounts in MSNs.

  13. Combating QR-Code-Based Compromised Accounts in Mobile Social Networks (United States)

    Guo, Dong; Cao, Jian; Wang, Xiaoqi; Fu, Qiang; Li, Qiang


    Cyber Physical Social Sensing makes mobile social networks (MSNs) popular with users. However, such attacks are rampant as malicious URLs are spread covertly through quick response (QR) codes to control compromised accounts in MSNs to propagate malicious messages. Currently, there are generally two types of methods to identify compromised accounts in MSNs: one type is to analyze the potential threats on wireless access points and the potential threats on handheld devices’ operation systems so as to stop compromised accounts from spreading malicious messages; the other type is to apply the method of detecting compromised accounts in online social networks to MSNs. The above types of methods above focus neither on the problems of MSNs themselves nor on the interaction of sensors’ messages, which leads to the restrictiveness of platforms and the simplification of methods. In order to stop the spreading of compromised accounts in MSNs effectively, the attacks have to be traced to their sources first. Through sensors, users exchange information in MSNs and acquire information by scanning QR codes. Therefore, analyzing the traces of sensor-related information helps to identify the compromised accounts in MSNs. This paper analyzes the diversity of information sending modes of compromised accounts and normal accounts, analyzes the regularity of GPS (Global Positioning System)-based location information, and introduces the concepts of entropy and conditional entropy so as to construct an entropy-based model based on machine learning strategies. To achieve the goal, about 500,000 accounts of Sina Weibo and about 100 million corresponding messages are collected. Through the validation, the accuracy rate of the model is proved to be as high as 87.6%, and the false positive rate is only 3.7%. Meanwhile, the comparative experiments of the feature sets prove that sensor-based location information can be applied to detect the compromised accounts in MSNs. PMID:27657071

  14. Lophotrochozoan mitochondrial genomes

    Energy Technology Data Exchange (ETDEWEB)

    Valles, Yvonne; Boore, Jeffrey L.


    Progress in both molecular techniques and phylogeneticmethods has challenged many of the interpretations of traditionaltaxonomy. One example is in the recognition of the animal superphylumLophotrochozoa (annelids, mollusks, echiurans, platyhelminthes,brachiopods, and other phyla), although the relationships within thisgroup and the inclusion of some phyla remain uncertain. While much ofthis progress in phylogenetic reconstruction has been based on comparingsingle gene sequences, we are beginning to see the potential of comparinglarge-scale features of genomes, such as the relative order of genes.Even though tremendous progress is being made on the sequencedetermination of whole nuclear genomes, the dataset of choice forgenome-level characters for many animals across a broad taxonomic rangeremains mitochondrial genomes. We review here what is known aboutmitochondrial genomes of the lophotrochozoans and discuss the promisethat this dataset will enable insight into theirrelationships.

  15. Respiratory active mitochondrial supercomplexes. (United States)

    Acín-Pérez, Rebeca; Fernández-Silva, Patricio; Peleato, Maria Luisa; Pérez-Martos, Acisclo; Enriquez, Jose Antonio


    The structural organization of the mitochondrial respiratory complexes as four big independently moving entities connected by the mobile carriers CoQ and cytochrome c has been challenged recently. Blue native gel electrophoresis reveals the presence of high-molecular-weight bands containing several respiratory complexes and suggesting an in vivo assembly status of these structures (respirasomes). However, no functional evidence of the activity of supercomplexes as true respirasomes has been provided yet. We have observed that (1) supercomplexes are not formed when one of their component complexes is absent; (2) there is a temporal gap between the formation of the individual complexes and that of the supercomplexes; (3) some putative respirasomes contain CoQ and cytochrome c; (4) isolated respirasomes can transfer electrons from NADH to O(2), that is, they respire. Therefore, we have demonstrated the existence of a functional respirasome and propose a structural organization model that accommodates these findings.

  16. More Than Tiny Sacks: Stem Cell Exosomes as Cell-Free Modality for Cardiac Repair. (United States)

    Kishore, Raj; Khan, Mohsin


    Stem cell therapy provides immense hope for regenerating the pathological heart, yet has been marred by issues surrounding the effectiveness, unclear mechanisms, and survival of the donated cell population in the ischemic myocardial milieu. Poor survival and engraftment coupled to inadequate cardiac commitment of the adoptively transferred stem cells compromises the improvement in cardiac function. Various alternative approaches to enhance the efficacy of stem cell therapies and to overcome issues with cell therapy have been used with varied success. Cell-free components, such as exosomes enriched in proteins, messenger RNAs, and miRs characteristic of parental stem cells, represent a potential approach for treating cardiovascular diseases. Recently, exosomes from different kinds of stem cells have been effectively used to promote cardiac function in the pathological heart. The aim of this review is to summarize current research efforts on stem cell exosomes, including their potential benefits and limitations to develop a potentially viable therapy for cardiovascular problems.

  17. Sigmoid volvulus in a patient with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS): a rare occurrence. (United States)

    Hallac, Alexander; Keshava, Hari B; Morris-Stiff, Gareth; Ibrahim, Samuel


    Mitochondrial diseases are rare and devastating, with a wide spectrum of clinical presentations and systemic symptoms. The majority of the published literature focuses on the neuromuscular manifestations and genetic components of this mitochondrial cytopathy, however, cardiac, renal, endocrine and gastrointestinal manifestations may also be present. The authors report a case detailing a 56-year-old woman's final hospitalisation from the gastrointestinal sequelae of mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) (Co Q10 deficiency variant). She presented with abdominal pain and distension associated with lactic acidosis, and was shown on imaging to have a colon perforation. This resulted in emergent surgery at which a necrotic colon secondary to a sigmoid colon was identified. Following four subsequent operations, and the development of multiorgan failure, care was eventually withdrawn. Practitioners of patients with MELAS should be cognisant of the rare but devastating gastrointestinal consequences of mitochondrial diseases.


    Directory of Open Access Journals (Sweden)

    Victor eSamokhvalov


    Full Text Available Hypoxia-reoxygenation (H/R injury is known to cause extensive injury to cardiac myocardium promoting development of cardiac dysfunction. Despite the vast number of studies dedicated to studying H/R injury, the molecular mechanisms behind it are multiple, complex and remain very poorly understood, which makes development of novel pharmacological agents challenging. Docosahexaenoic acid (DHA, 22:6n3 is an n-3 polyunsaturated fatty acid (PUFA obtained from dietary sources, which produces numerous effects including regulation of cell survival and death mechanisms. The beneficial effects of DHA toward the cardiovascular system are well documented but the relative role of DHA or one of its more potent metabolites is unresolved. Emerging evidence indicates that cytochrome P450 (CYP epoxygenase metabolites of DHA, epoxydocosapentaenoic acids (EDPs, have more potent biological activity than DHA in cardiac cells. In this study we examined whether EDPs protect HL-1 cardiac cells from H/R injury. Our observations demonstrate that treatment with 19,20-EDP protected HL-1 cardiac cells from H/R damage through a mechanism(s protecting and enhancing mitochondrial quality. EDP treatment increased the relative rates of mitobiogenesis and mitochondrial respiration in control and H/R exposed cardiac cells. The observed EDP protective response toward H/R injury involved SIRT1-dependent pathways.

  19. SIRT Is Required for EDP-Mediated Protective Responses toward Hypoxia-Reoxygenation Injury in Cardiac Cells. (United States)

    Samokhvalov, Victor; Jamieson, Kristi L; Fedotov, Ilia; Endo, Tomoko; Seubert, John M


    Hypoxia-reoxygenation (H/R) injury is known to cause extensive injury to cardiac myocardium promoting development of cardiac dysfunction. Despite the vast number of studies dedicated to studying H/R injury, the molecular mechanisms behind it are multiple, complex, and remain very poorly understood, which makes development of novel pharmacological agents challenging. Docosahexaenoic acid (DHA, 22:6n3) is an n - 3 polyunsaturated fatty acid obtained from dietary sources, which produces numerous effects including regulation of cell survival and death mechanisms. The beneficial effects of DHA toward the cardiovascular system are well documented but the relative role of DHA or one of its more potent metabolites is unresolved. Emerging evidence indicates that cytochrome P450 (CYP) epoxygenase metabolites of DHA, epoxydocosapentaenoic acids (EDPs), have more potent biological activity than DHA in cardiac cells. In this study we examined whether EDPs protect HL-1 cardiac cells from H/R injury. Our observations demonstrate that treatment with 19,20-EDP protected HL-1 cardiac cells from H/R damage through a mechanism(s) protecting and enhancing mitochondrial quality. EDP treatment increased the relative rates of mitobiogenesis and mitochondrial respiration in control and H/R exposed cardiac cells. The observed EDP protective response toward H/R injury involved SIRT1-dependent pathways.

  20. Cardiac myocyte exosomes: stability, HSP60, and proteomics. (United States)

    Malik, Z A; Kott, K S; Poe, A J; Kuo, T; Chen, L; Ferrara, K W; Knowlton, A A


    Exosomes, which are 50- to 100-nm-diameter lipid vesicles, have been implicated in intercellular communication, including transmitting malignancy, and as a way for viral particles to evade detection while spreading to new cells. Previously, we demonstrated that adult cardiac myocytes release heat shock protein (HSP)60 in exosomes. Extracellular HSP60, when not in exosomes, causes cardiac myocyte apoptosis via the activation of Toll-like receptor 4. Thus, release of HSP60 from exosomes would be damaging to the surrounding cardiac myocytes. We hypothesized that 1) pathological changes in the environment, such as fever, change in pH, or ethanol consumption, would increase exosome permeability; 2) different exosome inducers would result in different exosomal protein content; 3) ethanol at "physiological" concentrations would cause exosome release; and 4) ROS production is an underlying mechanism of increased exosome production. We found the following: first, exosomes retained their protein cargo under different physiological/pathological conditions, based on Western blot analyses. Second, mass spectrometry demonstrated that the protein content of cardiac exosomes differed significantly from other types of exosomes in the literature and contained cytosolic, sarcomeric, and mitochondrial proteins. Third, ethanol did not affect exosome stability but greatly increased the production of exosomes by cardiac myocytes. Fourth, ethanol- and hypoxia/reoxygenation-derived exosomes had different protein content. Finally, ROS inhibition reduced exosome production but did not completely inhibit it. In conclusion, exosomal protein content is influenced by the cell source and stimulus for exosome formation. ROS stimulate exosome production. The functions of exosomes remain to be fully elucidated.

  1. Moxonidine modulates cytokine signalling and effects on cardiac cell viability. (United States)

    Aceros, Henry; Farah, Georges; Noiseux, Nicolas; Mukaddam-Daher, Suhayla


    Regression of left ventricular hypertrophy and improved cardiac function in SHR by the centrally acting imidazoline I1-receptor agonist, moxonidine, are associated with differential actions on circulating and cardiac cytokines. Herein, we investigated cell-type specific I1-receptor (also known as nischarin) signalling and the mechanisms through which moxonidine may interfere with cytokines to affect cardiac cell viability. Studies were performed on neonatal rat cardiomyocytes and fibroblasts incubated with interleukin (IL)-1β (5 ng/ml), tumor necrosis factor (TNF)-α (10 ng/ml), and moxonidine (10(-7) and 10(-5) M), separately and in combination, for 15 min, and 24 and 48 h for the measurement of MAPKs (ERK1/2, JNK, and p38) and Akt activation and inducible NOS (iNOS) expression, by Western blotting, and cardiac cell viability/proliferation and apoptosis by flow cytometry, MTT assay, and Live/Dead assay. Participation of imidazoline I1-receptors and the signalling proteins in the detected effects was identified using imidazoline I1-receptor antagonist and signalling protein inhibitors. The results show that IL-1β, and to a lower extent, TNF-α, causes cell death and that moxonidine protects against starvation- as well as IL-1β -induced mortality, mainly by maintaining membrane integrity, and in part, by improving mitochondrial activity. The protection involves activation of Akt, ERK1/2, p38, JNK, and iNOS. In contrast, moxonidine stimulates basal and IL-1β-induced fibroblast mortality by mechanisms that include inhibition of JNK and iNOS. Thus, apart from their actions on the central nervous system, imidazoline I1-receptors are directly involved in cardiac cell growth and death, and may play an important role in cardiovascular diseases associated with inflammation.

  2. Modulation of intracellular calcium waves and triggered activities by mitochondrial ca flux in mouse cardiomyocytes.

    Directory of Open Access Journals (Sweden)

    Zhenghang Zhao

    Full Text Available Recent studies have suggested that mitochondria may play important roles in the Ca(2+ homeostasis of cardiac myocytes. However, it is still unclear if mitochondrial Ca(2+ flux can regulate the generation of Ca(2+ waves (CaWs and triggered activities in cardiac myocytes. In the present study, intracellular/cytosolic Ca(2+ (Cai (2+ was imaged in Fluo-4-AM loaded mouse ventricular myocytes. Spontaneous sarcoplasmic reticulum (SR Ca(2+ release and CaWs were induced in the presence of high (4 mM external Ca(2+ (Cao (2+. The protonophore carbonyl cyanide p-(trifluoromethoxyphenylhydrazone (FCCP reversibly raised basal Cai (2+ levels even after depletion of SR Ca(2+ in the absence of Cao (2+ , suggesting Ca(2+ release from mitochondria. FCCP at 0.01 - 0.1 µM partially depolarized the mitochondrial membrane potential (Δψ m and increased the frequency and amplitude of CaWs in a dose-dependent manner. Simultaneous recording of cell membrane potentials showed the augmentation of delayed afterdepolarization amplitudes and frequencies, and induction of triggered action potentials. The effect of FCCP on CaWs was mimicked by antimycin A (an electron transport chain inhibitor disrupting Δψ m or Ru360 (a mitochondrial Ca(2+ uniporter inhibitor, but not by oligomycin (an ATP synthase inhibitor or iodoacetic acid (a glycolytic inhibitor, excluding the contribution of intracellular ATP levels. The effects of FCCP on CaWs were counteracted by the mitochondrial permeability transition pore blocker cyclosporine A, or the mitochondrial Ca(2+ uniporter activator kaempferol. Our results suggest that mitochondrial Ca(2+ release and uptake exquisitely control the local Ca(2+ level in the micro-domain near SR ryanodine receptors and play an important role in regulation of intracellular CaWs and arrhythmogenesis.

  3. Diagnosing Mitochondrial Disorder without Sophisticated Means

    Directory of Open Access Journals (Sweden)

    Josef Finsterer


    Full Text Available Mitochondrial disorders (MIDs require biochemical or genetic investigations for being diagnosed. In some cases, however, the diagnosis can be suspected upon the syndromic phenotype or upon clinical presentation and family history, as in the following case. The patient was a 74-year-old male admitted for worsening of pre-existing left-sided ptosis and ophthalmoparesis after a birthday party. The history was positive for arterial hypertension, hypertrophic cardiomyopathy with systolic dysfunction, diabetes-type 2, mild renal insufficiency, thyroiditis, and polyneuropathy. Instrumental investigations additionally revealed hepatopathy, hyperlipidemia, hyperuricemia, bifascicular block, white matter lesions, and subacute stroke. Systolic dysfunction resolved upon adequate cardiac treatment. On hospital day 11 the patient suddenly developed asystole. He was successfully resuscitated but died a few hours later from acute myocardial infarction. Surprisingly, a more extensive family history was positive for myopathy (patient, brother, daughter, neuropathy (patient, hypoacusis (patient, Parkinson syndrome (mother, spasticity (son, diabetes (patient, son, renal failure (patient, and generalized atherosclerosis (patient. The individual and family history was strongly suggestive of an MID. In conclusion, individual and family history may strongly suggest MID. Phenotypic variability may be high between family members affected by an MID. MID may be associated with an increasing atherosclerotic risk lastly resulting in coronary heart disease and death.

  4. Cardiac mitochondria in heart failure: normal cardiolipin profile and increased threonine phosphorylation of complex IV. (United States)

    Rosca, Mariana; Minkler, Paul; Hoppel, Charles L


    Mitochondrial dysfunction is a major contributor in heart failure (HF). We investigated whether the decrease in respirasome organization reported by us previously in cardiac mitochondria in HF is due to changes in the phospholipids of the mitochondrial inner membrane or modifications of the subunits of the electron transport chain (ETC) complexes. The contents of the main phospholipid species, including cardiolipin, as well as the molecular species of cardiolipin were unchanged in cardiac mitochondria in HF. Oxidized cardiolipin molecular species were not observed. In heart mitochondria isolated from HF, complex IV not incorporated into respirasomes exhibits increased threonine phosphorylation. Since HF is associated with increased adrenergic drive to cardiomyocytes, this increased protein phosphorylation might be explained by the involvement of cAMP-activated protein kinase. Does the preservation of cAMP-induced phosphorylation changes of mitochondrial proteins or the addition of exogenous cAMP have similar effects on oxidative phosphorylation? The usage of phosphatase inhibitors revealed a specific decrease in complex I-supported respiration with glutamate. In saponin-permeabilized cardiac fibers, pre-incubation with cAMP decreases oxidative phosphorylation due to a defect localized at complex IV of the ETC inter alia. We propose that phosphorylation of specific complex IV subunits decreases oxidative phosphorylation either by limiting the incorporation of complex IV in supercomplexes or by decreasing supercomplex stability.

  5. Genetic counseling in mitochondrial disease. (United States)

    Vento, Jodie M; Pappa, Belen


    Mitochondrial diseases are a genetically and clinically diverse group of disorders that arise as a result of dysfunction of the mitochondria. Mitochondrial disorders can be caused by alterations in nuclear DNA and/or mitochondrial DNA. Although some mitochondrial syndromes have been described clearly in the literature many others present as challenging clinical cases with multisystemic involvement at variable ages of onset. Given the clinical variability and genetic heterogeneity of these conditions, patients and their families often experience a lengthy and complicated diagnostic process. The diagnostic journey may be characterized by heightened levels of uncertainty due to the delayed diagnosis and the absence of a clear prognosis, among other factors. Uncertainty surrounding issues of family planning and genetic testing may also affect the patient. The role of the genetic counselor is particularly important to help explain these complexities and support the patient and family's ability to achieve effective coping strategies in dealing with increased levels of uncertainty.

  6. The presence of multiple cellular defects associated with a novel G50E iron-sulfur cluster scaffold protein (ISCU) mutation leads to development of mitochondrial myopathy. (United States)

    Saha, Prasenjit Prasad; Kumar, S K Praveen; Srivastava, Shubhi; Sinha, Devanjan; Pareek, Gautam; D'Silva, Patrick


    Iron-sulfur (Fe-S) clusters are versatile cofactors involved in regulating multiple physiological activities, including energy generation through cellular respiration. Initially, the Fe-S clusters are assembled on a conserved scaffold protein, iron-sulfur cluster scaffold protein (ISCU), in coordination with iron and sulfur donor proteins in human mitochondria. Loss of ISCU function leads to myopathy, characterized by muscle wasting and cardiac hypertrophy. In addition to the homozygous ISCU mutation (g.7044G→C), compound heterozygous patients with severe myopathy have been identified to carry the c.149G→A missense mutation converting the glycine 50 residue to glutamate. However, the physiological defects and molecular mechanism associated with G50E mutation have not been elucidated. In this report, we uncover mechanistic insights concerning how the G50E ISCU mutation in humans leads to the development of severe ISCU myopathy, using a human cell line and yeast as the model systems. The biochemical results highlight that the G50E mutation results in compromised interaction with the sulfur donor NFS1 and the J-protein HSCB, thus impairing the rate of Fe-S cluster synthesis. As a result, electron transport chain complexes show significant reduction in their redox properties, leading to loss of cellular respiration. Furthermore, the G50E mutant mitochondria display enhancement in iron level and reactive oxygen species, thereby causing oxidative stress leading to impairment in the mitochondrial functions. Thus, our findings provide compelling evidence that the respiration defect due to impaired biogenesis of Fe-S clusters in myopathy patients leads to manifestation of complex clinical symptoms.

  7. Cardiac fatty acid oxidation in heart failure associated with obesity and diabetes. (United States)

    Fukushima, Arata; Lopaschuk, Gary D


    Obesity and diabetes are major public health problems, and are linked to the development of heart failure. Emerging data highlight the importance of alterations in cardiac energy metabolism as a major contributor to cardiac dysfunction related to obesity and diabetes. Increased rates of fatty acid oxidation and decreased rates of glucose utilization are two prominent changes in cardiac energy metabolism that occur in obesity and diabetes. This metabolic profile is probably both a cause and consequence of a prominent cardiac insulin resistance, which is accompanied by a decrease in both cardiac function and efficiency, and by the accumulation of potentially toxic lipid metabolites in the heart that can further exaggerate insulin resistance and cardiac dysfunction. The high cardiac fatty acid oxidation rates seen in obesity and diabetes are attributable to several factors, including: 1) increased fatty acid supply and uptake into the cardiomyocyte, 2) increased transcription of fatty acid metabolic enzymes, 3) decreased allosteric control of mitochondrial fatty acid uptake and fatty acid oxidation, and 4) increased post-translational acetylation control of various fatty acid oxidative enzymes. Emerging evidence suggests that therapeutic approaches aimed at switching the balance of cardiac energy substrate preference from fatty acid oxidation to glucose use can prevent cardiac dysfunction associated with obesity and diabetes. Modulating acetylation control of fatty acid oxidative enzymes is also a potentially attractive strategy, although presently this is limited to precursors of nicotinamide adenine or nonspecific activators of deacetylation such as resveratrol. This review will focus on the metabolic alterations in the heart that occur in obesity and diabetes, as well as on the molecular mechanisms controlling these metabolic changes. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk.

  8. Mitochondrial Replacement: Ethics And Identity


    Wrigley, Anthony; Wilkinson, Stephen; Appleby, John B


    Mitochondrial replacement techniques (MRTs) have the potential to allow prospective parents who are at risk of passing on debilitating or even life-threatening mitochondrial disorders to have healthy children to whom they are genetically related. Ethical concerns have however been raised about these techniques. This article focuses on one aspect of the ethical debate, the question of whether there is any moral difference between the two types of MRT proposed: Pronuclear Transfer (PNT) and Mat...

  9. Mitochondrial dysfunction and organophosphorus compounds

    Energy Technology Data Exchange (ETDEWEB)

    Karami-Mohajeri, Somayyeh [Department of Toxicology and Pharmacology, Faculty of Pharmacy, and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Toxicology and Pharmacology, Faculty of Pharmacy, and Pharmaceutical Sciences Research Center, Kerman University of Medical Sciences, Kerman (Iran, Islamic Republic of); Abdollahi, Mohammad, E-mail: Mohammad.Abdollahi@UToronto.Ca [Department of Toxicology and Pharmacology, Faculty of Pharmacy, and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)


    Organophosphorous (OPs) pesticides are the most widely used pesticides in the agriculture and home. However, many acute or chronic poisoning reports about OPs have been published in the recent years. Mitochondria as a site of cellular oxygen consumption and energy production can be a target for OPs poisoning as a non-cholinergic mechanism of toxicity of OPs. In the present review, we have reviewed and criticized all the evidences about the mitochondrial dysfunctions as a mechanism of toxicity of OPs. For this purpose, all biochemical, molecular, and morphological data were retrieved from various studies. Some toxicities of OPs are arisen from dysfunction of mitochondrial oxidative phosphorylation through alteration of complexes I, II, III, IV and V activities and disruption of mitochondrial membrane. Reductions of adenosine triphosphate (ATP) synthesis or induction of its hydrolysis can impair the cellular energy. The OPs disrupt cellular and mitochondrial antioxidant defense, reactive oxygen species generation, and calcium uptake and promote oxidative and genotoxic damage triggering cell death via cytochrome C released from mitochondria and consequent activation of caspases. The mitochondrial dysfunction induced by OPs can be restored by use of antioxidants such as vitamin E and C, alpha-tocopherol, electron donors, and through increasing the cytosolic ATP level. However, to elucidate many aspect of mitochondrial toxicity of Ops, further studies should be performed. - Highlights: • As a non-cholinergic mechanism of toxicity, mitochondria is a target for OPs. • OPs affect action of complexes I, II, III, IV and V in the mitochondria. • OPs reduce mitochondrial ATP. • OPs promote oxidative and genotoxic damage via release of cytochrome C from mitochondria. • OP-induced mitochondrial dysfunction can be restored by increasing the cytosolic ATP.

  10. Computed tomography in mitochondrial cytopathy

    Energy Technology Data Exchange (ETDEWEB)

    Egger, J.; Kendall, B.E.


    The clinical and computed tomographic (CT) findings in 11 proven cases of mitochondrial cytopathy (mitochondrial myopathy, Kearns Sayre syndrome, ophthalmoplegia plus) were studied. The CT changes included focal low density lesions in the basal ganglia and white matter and atrophy which could be slight or diffuse and severe. Calcification has been described in the basal ganglia, but did not occur in our series. Serial CT showed progression of the abnormalities. The differential diagnosis is discussed.

  11. Combination of angiotensin II and l-NG-nitroarginine methyl ester exacerbates mitochondrial dysfunction and oxidative stress to cause heart failure. (United States)

    Hamilton, Dale J; Zhang, Aijun; Li, Shumin; Cao, Tram N; Smith, Jessie A; Vedula, Indira; Cordero-Reyes, Andrea M; Youker, Keith A; Torre-Amione, Guillermo; Gupte, Anisha A


    Mitochondrial dysfunction has been implicated as a cause of energy deprivation in heart failure (HF). Herein, we tested individual and combined effects of two pathogenic factors of nonischemic HF, inhibition of nitric oxide synthesis [with l-N(G)-nitroarginine methyl ester (l-NAME)] and hypertension [with angiotensin II (AngII)], on myocardial mitochondrial function, oxidative stress, and metabolic gene expression. l-NAME and AngII were administered individually and in combination to mice for 5 wk. Although all treatments increased blood pressure and reduced cardiac contractile function, the l-NAME + AngII group was associated with the most severe HF, as characterized by edema, hypertrophy, oxidative stress, increased expression of Nppa and Nppb, and decreased expression of Atp2a2 and Camk2b. l-NAME + AngII-treated mice exhibited robust deterioration of cardiac mitochondrial function, as observed by reduced respiratory control ratios in subsarcolemmal mitochondria and reduced state 3 levels in interfibrillar mitochondria for complex I but not for complex II substrates. Cardiac myofibrils showed reduced ADP-supported and oligomycin-inhibited oxygen consumption. Mitochondrial functional impairment was accompanied by reduced mitochondrial DNA content and activities of pyruvate dehydrogenase and complex I but increased H2O2 production and tissue protein carbonyls in hearts from AngII and l-NAME + AngII groups. Microarray analyses revealed the majority of the gene changes attributed to the l-NAME + AngII group. Pathway analyses indicated significant changes in metabolic pathways, such as oxidative phosphorylation, mitochondrial function, cardiac hypertrophy, and fatty acid metabolism in l-NAME + AngII hearts. We conclude that l-NAME + AngII is associated with impaired mitochondrial respiratory function and increased oxidative stress compared with either l-NAME or AngII alone, resulting in nonischemic HF.

  12. Hypokalemia and sudden cardiac death

    DEFF Research Database (Denmark)

    Kjeldsen, Keld


    Worldwide, approximately three million people suffer sudden cardiac death annually. These deaths often emerge from a complex interplay of substrates and triggers. Disturbed potassium homeostasis among heart cells is an example of such a trigger. Thus, hypokalemia and, also, more transient...... of fatal arrhythmia and sudden cardiac death a patient is, the more attention should be given to the potassium homeostasis....

  13. The Danish Cardiac Rehabilitation Database

    DEFF Research Database (Denmark)

    Zwisler, Ann-Dorthe; Rossau, Henriette Knold; Nakano, Anne


    AIM OF DATABASE: The Danish Cardiac Rehabilitation Database (DHRD) aims to improve the quality of cardiac rehabilitation (CR) to the benefit of patients with coronary heart disease (CHD). STUDY POPULATION: Hospitalized patients with CHD with stenosis on coronary angiography treated with percutane...

  14. Biosynthesis of cardiac natriuretic peptides

    DEFF Research Database (Denmark)

    Goetze, Jens Peter


    . An inefficient post-translational prohormone maturation will also affect the biology of the cardiac natriuretic peptide system. This review aims at summarizing the myocardial synthesis of natriuretic peptides focusing on B-type natriuretic peptide, where new data has disclosed cardiac myocytes as highly...

  15. [Cardiac myxoma with cerebral metastases]. (United States)

    Bazin, A; Peruzzi, P; Baudrillard, J C; Pluot, M; Rousseaux, P


    A 56 year old woman developed multiple metastases in the cerebrum and cerebellum, four years after cardiac intervention on a left atrial myxoma. The absence of stroke is noteworthy. Multiple high density lesions with contrast enhancement were seen by CT scan, suggesting metastatic neoplasms. Histological examination confirmed the diagnosis of metastases of cardiac myxoma. Only four cases were recorded in the literature.

  16. Health Instruction Packages: Cardiac Anatomy. (United States)

    Phillips, Gwen; And Others

    Text, illustrations, and exercises are utilized in these five learning modules to instruct nurses, students, and other health care professionals in cardiac anatomy and functions and in fundamental electrocardiographic techniques. The first module, "Cardiac Anatomy and Physiology: A Review" by Gwen Phillips, teaches the learner to draw…

  17. Pneumothorax in cardiac pacing

    DEFF Research Database (Denmark)

    Kirkfeldt, Rikke Esberg; Johansen, Jens Brock; Nohr, Ellen Aagaard;


    AIM: To identify risk factors for pneumothorax treated with a chest tube after cardiac pacing device implantation in a population-based cohort.METHODS AND RESULTS: A nationwide cohort study was performed based on data on 28 860 patients from the Danish Pacemaker Register, which included all Danish...... patients who received their first pacemaker (PM) or cardiac resynchronization device from 1997 to 2008. Multiple logistic regression was used to estimate adjusted odds ratios (aOR) with 95% confidence intervals for the association between risk factors and pneumothorax treated with a chest tube. The median...... age was 77 years (25th and 75th percentile: 69-84) and 55% were male (n = 15 785). A total of 190 patients (0.66%) were treated for pneumothorax, which was more often in women [aOR 1.9 (1.4-2.6)], and in patients with age >80 years [aOR 1.4 (1.0-1.9)], a prior history of chronic obstructive pulmonary...

  18. Leadership in cardiac surgery. (United States)

    Rao, Christopher; Patel, Vanash; Ibrahim, Michael; Ahmed, Kamran; Wong, Kathie A; Darzi, Ara; von Segesser, Ludwig K; Athanasiou, Thanos


    Despite the efficacy of cardiac surgery, less invasive interventions with more uncertain long-term outcomes are increasingly challenging surgery as first-line treatment for several congenital, degenerative and ischemic cardiac diseases. The specialty must evolve if it is to ensure its future relevance. More importantly, it must evolve to ensure that future patients have access to treatments with proven long-term effectiveness. This cannot be achieved without dynamic leadership; however, our contention is that this is not enough. The demands of a modern surgical career and the importance of the task at hand are such that the serendipitous emergence of traditional charismatic leadership cannot be relied upon to deliver necessary change. We advocate systematic analysis and strategic leadership at a local, national and international level in four key areas: Clinical Care, Research, Education and Training, and Stakeholder Engagement. While we anticipate that exceptional individuals will continue to shape the future of our specialty, the creation of robust structures to deliver collective leadership in these key areas is of paramount importance.

  19. Cardiac system bioenergetics: metabolic basis of the Frank-Starling law. (United States)

    Saks, Valdur; Dzeja, Petras; Schlattner, Uwe; Vendelin, Marko; Terzic, Andre; Wallimann, Theo


    The fundamental principle of cardiac behaviour is described by the Frank-Starling law relating force of contraction during systole with end-diastolic volume. While both work and respiration rates increase linearly with imposed load, the basis of mechano-energetic coupling in heart muscle has remained a long-standing enigma. Here, we highlight advances made in understanding of complex cellular and molecular mechanisms that orchestrate coupling of mitochondrial oxidative phosphorylation with ATP utilization for muscle contraction. Cardiac system bioenergetics critically depends on an interrelated metabolic infrastructure regulating mitochondrial respiration and energy fluxes throughout cellular compartments. The data reviewed indicate the significance of two interrelated systems regulating mitochondrial respiration and energy fluxes in cells: (1) the creatine kinase, adenylate kinase and glycolytic pathways that communicate flux changes generated by cellular ATPases within structurally organized enzymatic modules and networks; and (2) a secondary system based on mitochondrial participation in cellular calcium cycle, which adjusts substrate oxidation and energy-transducing processes to meet increasing cellular energy demands. By conveying energetic signals to metabolic sensors, coupled phosphotransfer reactions provide a high-fidelity regulation of the excitation-contraction cycle. Such integration of energetics with calcium signalling systems provides the basis for 'metabolic pacing', synchronizing the cellular electrical and mechanical activities with energy supply processes.

  20. CFTR activity and mitochondrial function

    Directory of Open Access Journals (Sweden)

    Angel Gabriel Valdivieso


    Full Text Available Cystic Fibrosis (CF is a frequent and lethal autosomal recessive disease, caused by mutations in the gene encoding the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR. Before the discovery of the CFTR gene, several hypotheses attempted to explain the etiology of this disease, including the possible role of a chloride channel, diverse alterations in mitochondrial functions, the overexpression of the lysosomal enzyme α-glucosidase and a deficiency in the cytosolic enzyme glucose 6-phosphate dehydrogenase. Because of the diverse mitochondrial changes found, some authors proposed that the affected gene should codify for a mitochondrial protein. Later, the CFTR cloning and the demonstration of its chloride channel activity turned the mitochondrial, lysosomal and cytosolic hypotheses obsolete. However, in recent years, using new approaches, several investigators reported similar or new alterations of mitochondrial functions in Cystic Fibrosis, thus rediscovering a possible role of mitochondria in this disease. Here, we review these CFTR-driven mitochondrial defects, including differential gene expression, alterations in oxidative phosphorylation, calcium homeostasis, oxidative stress, apoptosis and innate immune response, which might explain some characteristics of the complex CF phenotype and reveals potential new targets for therapy.

  1. Mitochondrial diseases: advances and issues (United States)

    Scarpelli, Mauro; Todeschini, Alice; Volonghi, Irene; Padovani, Alessandro; Filosto, Massimiliano


    Mitochondrial diseases (MDs) are a clinically heterogeneous group of disorders caused by a dysfunction of the mitochondrial respiratory chain. They can be related to mutation of genes encoded using either nuclear DNA or mitochondrial DNA. The advent of next generation sequencing and whole exome sequencing in studying the molecular bases of MDs will bring about a revolution in the field of mitochondrial medicine, also opening the possibility of better defining pathogenic mechanisms and developing novel therapeutic approaches for these devastating disorders. The canonical rules of mitochondrial medicine remain milestones, but novel issues have been raised following the use of advanced diagnostic technologies. Rigorous validation of the novel mutations detected using deep sequencing in patients with suspected MD, and a clear definition of the natural history, outcome measures, and biomarkers that could be usefully adopted in clinical trials, are mandatory goals for the scientific community. Today, therapy is often inadequate and mostly palliative. However, important advances have been made in treating some clinical entities, eg, mitochondrial neuro-gastrointestinal encephalomyopathy, for which approaches using allogeneic hematopoietic stem cell transplantation, orthotopic liver transplantation, and carrier erythrocyte entrapped thymidine phosphorylase enzyme therapy have recently been developed. Promising new treatment methods are being identified so that researchers, clinicians, and patients can join forces to change the history of these untreatable disorders. PMID:28243136

  2. Pemphigus vulgaris antibodies target the mitochondrial nicotinic acetylcholine receptors that protect keratinocytes from apoptolysis. (United States)

    Chernyavsky, Alex; Chen, Yumay; Wang, Ping H; Grando, Sergei A


    The mechanism of detachment and death of keratinocytes in pemphigus vulgaris (PV) involves pro-apoptotic action of constellations of autoantibodies determining disease severity and response to treatment. The presence of antibodies to nicotinic acetylcholine receptors (nAChRs) and the therapeutic efficacy of cholinomimetics in PV is well-established. Recently, adsorption of anti-mitochondrial antibodies abolished the ability of PVIgGs to cause acantholysis, demonstrating their pathophysiological significance. Since, in addition to cell membrane, nAChRs are also present on the mitochondrial outer membrane, wherein they act to prevent activation of intrinsic (mitochondrial apoptosis), we hypothesized that mitochondrial (mt)-nAChRs might be targeted by PVIgGs. To test this hypothesis, we employed the immunoprecipitation-western blot assay of keratinocyte mitochondrial proteins that visualized the α3, α5, α7, α9, α10, β2 and β4 mt-nAChR subunits precipitated by PV IgGs, suggesting that functions of mt-nAChRs are compromised in PV. To pharmacologically counteract the pro-apoptotic action of anti-mitochondrial antibodies in PV, we exposed naked keratinocyte mitochondria to PVIgGs in the presence of the nicotinic agonist nicotine ± antagonists, and measured cytochrome c (CytC) release. Nicotine abolished PVIgG-dependent CytC release, showing a dose-dependent effect, suggesting that protection of mitochondria can be a novel mechanism of therapeutic action of nicotinic agonists in PV. The obtained results indicated that the mt-nAChRs targeted by anti-mitochondrial antibodies produced by PV patients are coupled to inhibition of CytC release, and that nicotinergic stimulation can abolish PVIgG-dependent activation of intrinsic apoptosis in KCs. Future studies should determine if and how the distinct anti-mt-nAChR antibodies penetrate KCs and correlate with disease severity.

  3. Mitochondrial structure and function are not different between nonfailing donor and end-stage failing human hearts. (United States)

    Holzem, Katherine M; Vinnakota, Kalyan C; Ravikumar, Vinod K; Madden, Eli J; Ewald, Gregory A; Dikranian, Krikor; Beard, Daniel A; Efimov, Igor R


    During human heart failure, the balance of cardiac energy use switches from predominantly fatty acids (FAs) to glucose. We hypothesized that this substrate shift was the result of mitochondrial degeneration; therefore, we examined mitochondrial oxidation and ultrastructure in the failing human heart by using respirometry, transmission electron microscopy, and gene expression studies of demographically matched donor and failing human heart left ventricular (LV) tissues. Surprisingly, respiratory capacities for failing LV isolated mitochondria (n = 9) were not significantly diminished compared with donor LV isolated mitochondria (n = 7) for glycolysis (pyruvate + malate)- or FA (palmitoylcarnitine)-derived substrates, and mitochondrial densities, assessed via citrate synthase activity, were consistent between groups. Transmission electron microscopy images also showed no ultrastructural remodeling for failing vs. donor mitochondria; however, the fraction of lipid droplets (LDs) in direct contact with a mitochondrion was reduced, and the average distance between an LD and its nearest neighboring mitochondrion was increased. Analysis of FA processing gene expression between donor and failing LVs revealed 0.64-fold reduced transcript levels for the mitochondrial-LD tether, perilipin 5, in the failing myocardium (P = 0.003). Thus, reduced FA use in heart failure may result from improper delivery, potentially via decreased perilipin 5 expression and mitochondrial-LD tethering, and not from intrinsic mitochondrial dysfunction.-Holzem, K. M., Vinnakota, K. C., Ravikumar, V. K., Madden, E. J., Ewald, G. A., Dikranian, K., Beard, D. A., Efimov, I. R. Mitochondrial structure and function are not different between nonfailing donor and end-stage failing human hearts.

  4. Cardiac remodeling and physical training post myocardial infarction

    Institute of Scientific and Technical Information of China (English)

    Michael; A; Garza; Emily; A; Wason; John; Q; Zhang


    After myocardial infarction(MI), the heart undergoes extensive myocardial remodeling through the accumulation of fibrous tissue in both the infarcted and noninfarcted myocardium, which distorts tissue structure, increases tissue stiffness, and accounts for ventricular dysfunction. There is growing clinical consensus that exercise training may beneficially alter the course of post-MI myocardial remodeling and improve cardiac function. This review summarizes the present state of knowledge regarding the effect of post-MI exercise training on infarcted hearts. Due to the degree of difficulty to study a viable human heart at both protein and molecular levels, most of the detailed studies have been performed by using animal models. Although there are some negative reports indicating that post-MI exercise may further cause deterioration of the wounded hearts, a growing body of research from both human and animal experiments demonstrates that post-MI exercise may beneficially alter the course of wound healing and improve cardiac function. Furthermore, the improved function is likely due to exercise training-induced mitigation of reninangiotensin-aldosterone system, improved balance between matrix metalloproteinase-1 and tissue inhibitor of matrix metalloproteinase-1, favorable myosin heavy chain isoform switch, diminished oxidative stress, enhanced antioxidant capacity, improved mitochondrial calcium handling, and boosted myocardial angiogenesis. Additionally, meta-analyses revealed that exercise-based cardiac rehabilitation has proven to be effective, and remains one of the least expensive therapies for both the prevention and treatment of cardiovascular disease, and prevents re-infarction.

  5. Accelerated cardiovascular magnetic resonance of the mouse heart using self-gated parallel imaging strategies does not compromise accuracy of structural and functional measures

    Directory of Open Access Journals (Sweden)

    Dörries Carola


    Full Text Available Abstract Background Self-gated dynamic cardiovascular magnetic resonance (CMR enables non-invasive visualization of the heart and accurate assessment of cardiac function in mouse models of human disease. However, self-gated CMR requires the acquisition of large datasets to ensure accurate and artifact-free reconstruction of cardiac cines and is therefore hampered by long acquisition times putting high demands on the physiological stability of the animal. For this reason, we evaluated the feasibility of accelerating the data collection using the parallel imaging technique SENSE with respect to both anatomical definition and cardiac function quantification. Results Findings obtained from accelerated data sets were compared to fully sampled reference data. Our results revealed only minor differences in image quality of short- and long-axis cardiac cines: small anatomical structures (papillary muscles and the aortic valve and left-ventricular (LV remodeling after myocardial infarction (MI were accurately detected even for 3-fold accelerated data acquisition using a four-element phased array coil. Quantitative analysis of LV cardiac function (end-diastolic volume (EDV, end-systolic volume (ESV, stroke volume (SV, ejection fraction (EF and LV mass in healthy and infarcted animals revealed no substantial deviations from reference (fully sampled data for all investigated acceleration factors with deviations ranging from 2% to 6% in healthy animals and from 2% to 8% in infarcted mice for the highest acceleration factor of 3.0. CNR calculations performed between LV myocardial wall and LV cavity revealed a maximum CNR decrease of 50% for the 3-fold accelerated data acquisition when compared to the fully-sampled acquisition. Conclusions We have demonstrated the feasibility of accelerated self-gated retrospective CMR in mice using the parallel imaging technique SENSE. The proposed method led to considerably reduced acquisition times, while preserving high

  6. Thymol, a dietary monoterpene phenol abrogates mitochondrial dysfunction in β-adrenergic agonist induced myocardial infarcted rats by inhibiting oxidative stress. (United States)

    Nagoor Meeran, M F; Jagadeesh, G S; Selvaraj, P


    Mitochondrial dysfunction has been suggested to be one of the important pathological events in isoproterenol (ISO), a synthetic catecholamine and β-adrenergic agonist induced myocardial infarction (MI). In this context, we have evaluated the impact of thymol against ISO induced oxidative stress and calcium uniporter malfunction involved in the pathology of mitochondrial dysfunction in rats. Male albino Wistar rats were pre and co-treated with thymol (7.5 mg/kg body weight) daily for 7 days. Isoproterenol (100 mg/kg body weight) was subcutaneously injected into rats on 6th and 7th day to induce MI. To explore the extent of cardiac mitochondrial damage, the activities/levels of cardiac marker enzymes, mitochondrial lipid peroxidation products, antioxidants, lipids, calcium, adenosine triphosphate and multi marker enzymes were evaluated. Isoproterenol induced myocardial infarcted rats showed a significant increase in the activities of cardiac diagnostic markers, heart mitochondrial lipid peroxidation, lipids, calcium, and a significant decrease in the activities/levels of heart mitochondrial superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, isocitrate, malate, α-ketoglutarate and NADH-dehydrogenases, cytochrome-C-oxidase, and adenosine triphosphate. Thymol pre and co-treatment showed near normalized effects on all the biochemical parameters studied. Transmission electron microscopic findings and mitochondrial swelling studies confirmed our biochemical findings. The in vitro study also revealed the potent free-radical scavenging activity of thymol. Thus, thymol attenuates the involvement of ISO against oxidative stress and calcium uniporter malfunction associated with mitochondrial dysfunction in rats.

  7. Sirtuin-3 (SIRT3) protein attenuates doxorubicin-induced oxidative stress and improves mitochondrial respiration in H9c2 cardiomyocytes (United States)

    Doxorubicin (DOX) is a chemotherapeutic agent effective in the treatment of many cancers. However, cardiac dysfunction caused by DOX limits its clinical use. DOX is believed to be harmful to cardiomyocytes by interfering with the mitochondrial phospholipid cardiolipin and causing inefficient electro...

  8. Mitochondrial diseases: advances and issues

    Directory of Open Access Journals (Sweden)

    Scarpelli M


    Full Text Available Mauro Scarpelli,1 Alice Todeschini,2 Irene Volonghi,2 Alessandro Padovani,2 Massimiliano Filosto2 1Department of Neuroscience, Unit of Neurology, Azienda Ospedaliera Universitaria Integrata Verona, Verona, Italy; 2Center for Neuromuscular Diseases and Neuropathies, Unit of Neurology, ASST “Spedali Civili”, University of Brescia, Brescia, Italy Abstract: Mitochondrial diseases (MDs are a clinically heterogeneous group of disorders caused by a dysfunction of the mitochondrial respiratory chain. They can be related to mutation of genes encoded using either nuclear DNA or mitochondrial DNA. The advent of next generation sequencing and whole exome sequencing in studying the molecular bases of MDs will bring about a revolution in the field of mitochondrial medicine, also opening the possibility of better defining pathogenic mechanisms and developing novel therapeutic approaches for these devastating disorders. The canonical rules of mitochondrial medicine remain milestones, but novel issues have been raised following the use of advanced diagnostic technologies. Rigorous validation of the novel mutations detected using deep sequencing in patients with suspected MD, and a clear definition of the natural history, outcome measures, and biomarkers that could be usefully adopted in clinical trials, are mandatory goals for the scientific community. Today, therapy is often inadequate and mostly palliative. However, important advances have been made in treating some clinical entities, eg, mitochondrial neuro-gastrointestinal encephalomyopathy, for which approaches using allogeneic hematopoietic stem cell transplantation, orthotopic liver transplantation, and carrier erythrocyte entrapped thymidine phosphorylase enzyme therapy have recently been developed. Promising new treatment methods are being identified so that researchers, clinicians, and patients can join forces to change the history of these untreatable disorders. Keywords: mitochondrial diseases

  9. Mitochondrial drug targets in neurodegenerative diseases. (United States)

    Lee, Jiyoun


    Growing evidence suggests that mitochondrial dysfunction is the main culprit in neurodegenerative diseases. Given the fact that mitochondria participate in diverse cellular processes, including energetics, metabolism, and death, the consequences of mitochondrial dysfunction in neuronal cells are inevitable. In fact, new strategies targeting mitochondrial dysfunction are emerging as potential alternatives to current treatment options for neurodegenerative diseases. In this review, we focus on mitochondrial proteins that are directly associated with mitochondrial dysfunction. We also examine recently identified small molecule modulators of these mitochondrial targets and assess their potential in research and therapeutic applications.

  10. Formation and Regulation of Mitochondrial Membranes

    Directory of Open Access Journals (Sweden)

    Laila Cigana Schenkel


    Full Text Available Mitochondrial membrane phospholipids are essential for the mitochondrial architecture, the activity of respiratory proteins, and the transport of proteins into the mitochondria. The accumulation of phospholipids within mitochondria depends on a coordinate synthesis, degradation, and trafficking of phospholipids between the endoplasmic reticulum (ER and mitochondria as well as intramitochondrial lipid trafficking. Several studies highlight the contribution of dietary fatty acids to the remodeling of phospholipids and mitochondrial membrane homeostasis. Understanding the role of phospholipids in the mitochondrial membrane and their metabolism will shed light on the molecular mechanisms involved in the regulation of mitochondrial function and in the mitochondrial-related diseases.

  11. Physics of Cardiac Arrhythmogenesis (United States)

    Karma, Alain


    A normal heartbeat is orchestrated by the stable propagation of an excitation wave that produces an orderly contraction. In contrast, wave turbulence in the ventricles, clinically known as ventricular fibrillation (VF), stops the heart from pumping and is lethal without prompt defibrillation. I review experimental, computational, and theoretical studies that have shed light on complex dynamical phenomena linked to the initiation, maintenance, and control of wave turbulence. I first discuss advances made to understand the precursor state to a reentrant arrhythmia where the refractory period of cardiac tissue becomes spatiotemporally disordered; this is known as an arrhythmogenic tissue substrate. I describe observed patterns of transmembrane voltage and intracellular calcium signaling that can contribute to this substrate, and symmetry breaking instabilities to explain their formation. I then survey mechanisms of wave turbulence and discuss novel methods that exploit electrical pacing stimuli to control precursor patterns and low-energy pulsed electric fields to control turbulence.

  12. Cancun Compromise

    Institute of Scientific and Technical Information of China (English)


    Countries take small steps toward addressing global climate change Participants at the UN Climate Change Confe-rence in Cancun from November 29 to December 11 didn’t reach an agreement until the last minute. The agreement was a small yet meaningful step in the international climate change negotiation process.

  13. Cancun Compromise

    Institute of Scientific and Technical Information of China (English)



    @@ Participants at the UN Climate Change Conference in Cancun from November 29 to December 11 didn't reach an agreement until the last minute. The agreement was a small yet meaningful step in the international climate change negotiation process.

  14. Platelets and cardiac arrhythmia

    Directory of Open Access Journals (Sweden)

    Jonas S De Jong


    Full Text Available Sudden cardiac death remains one of the most prevalent modes of death in industrialized countries, and myocardial ischemia due to thrombotic coronary occlusion is its primary cause. The role of platelets in the occurrence of SCD extends beyond coronary flow impairment by clot formation. Here we review the substances released by platelets during clot formation and their arrhythmic properties. Platelet products are released from three types of platelet granules: dense core granules, alpha-granules, and platelet lysosomes. The physiologic properties of dense granule products are of special interest as a potential source of arrhythmic substances. They are released readily upon activation and contain high concentrations of serotonin, histamine, purines, pyrimidines, and ions such as calcium and magnesium. Potential arrhythmic mechanisms of these substances, e.g. serotonin and high energy phosphates, include induction of coronary constriction, calcium overloading, and induction of delayed after-depolarizations. Alpha-granules produce thromboxanes and other arachidonic acid products with many potential arrhythmic effects mediated by interference with cardiac sodium, calcium and potassium channels. Alpha-granules also contain hundreds of proteins that could potentially serve as ligands to receptors on cardiomyocytes. Lysosomal products probably do not have an important arrhythmic effect. Platelet products and ischemia can induce coronary permeability, thereby enhancing interaction with surrounding cardiomyocytes. Antiplatelet therapy is known to improve survival after myocardial infarction. Although an important part of this effect results from prevention of coronary clot formation, there is evidence to suggest that antiplatelet therapy also induces anti-arrhythmic effects during ischemia by preventing the release of platelet activation products.

  15. Mediastinitis after cardiac transplantation

    Directory of Open Access Journals (Sweden)

    Noedir A. G. Stolf


    Full Text Available OBJECTIVE: Assessment of incidence and behavior of mediastinitis after cardiac transplantation. METHODS: From 1985 to 1999, 214 cardiac transplantations were performed, 12 (5.6% of the transplanted patients developed confirmed mediastinitis. Patient's ages ranged from 42 to 66 years (mean of 52.3±10.0 years and 10 (83.3% patients were males. Seven (58.3% patients showed sternal stability on palpation, 4 (33.3% patients had pleural empyema, and 2 (16.7% patients did not show purulent secretion draining through the wound. RESULTS: Staphylococcus aureus was the infectious agent identified in the wound secretion or in the mediastinum, or both, in 8 (66.7% patients. Staphylococcus epidermidis was identified in 2 (16.7% patients, Enterococcus faecalis in 1 (8.3% patient, and the cause of mediastinitis could not be determined in 1 (8.3% patient. Surgical treatment was performed on an emergency basis, and the extension of the débridement varied with local conditions. In 2 (16.7% patients, we chose to leave the surgical wound open and performed daily dressings with granulated sugar. Total sternal resection was performed in only 1 (8.3% patient. Out of this series, 5 (41.7% patients died, and the causes of death were related to the infection. Autopsy revealed persistence of mediastinitis in 1 (8.3% patient. CONCLUSION: Promptness in diagnosing mediastinitis and precocious surgical drainage have changed the natural evolution of this disease. Nevertheless, observance of the basic precepts of prophylaxis of infection is still the best way to treat mediastinitis.

  16. Metoclopramide-induced cardiac arrest

    Directory of Open Access Journals (Sweden)

    Martha M. Rumore


    Full Text Available The authors report a case of cardiac arrest in a patient receiving intravenous (IV metoclopramide and review the pertinent literature. A 62-year-old morbidly obese female admitted for a gastric sleeve procedure, developed cardiac arrest within one minute of receiving metoclopramide 10 mg via slow intravenous (IV injection. Bradycardia at 4 beats/min immediately appeared, progressing rapidly to asystole. Chest compressions restored vital function. Electrocardiogram (ECG revealed ST depression indicative of myocardial injury. Following intubation, the patient was transferred to the intensive care unit. Various cardiac dysrrhythmias including supraventricular tachycardia (SVT associated with hypertension and atrial fibrillation occurred. Following IV esmolol and metoprolol, the patient reverted to normal sinus rhythm. Repeat ECGs revealed ST depression resolution without pre-admission changes. Metoclopramide is a non-specific dopamine receptor antagonist. Seven cases of cardiac arrest and one of sinus arrest with metoclopramide were found in the literature. The metoclopramide prescribing information does not list precautions or adverse drug reactions (ADRs related to cardiac arrest. The reaction is not dose related but may relate to the IV administration route. Coronary artery disease was the sole risk factor identified. According to Naranjo, the association was possible. Other reports of cardiac arrest, severe bradycardia, and SVT were reviewed. In one case, five separate IV doses of 10 mg metoclopramide were immediately followed by asystole repeatedly. The mechanism(s underlying metoclopramide’s cardiac arrest-inducing effects is unknown. Structural similarities to procainamide may play a role. In view of eight previous cases of cardiac arrest from metoclopramide having been reported, further elucidation of this ADR and patient monitoring is needed. Our report should alert clinicians to monitor patients and remain diligent in surveillance and

  17. Fetal cardiac rhabdomyoma: case report

    Directory of Open Access Journals (Sweden)

    Seyed Mostafa Ghavami


    Full Text Available Background: The primary manifestation of cardiac tumors in embryonic period is a very rare condition. Cardiac rhabdomyomas most frequently arise in the ventricular myocardium, they may also occur in the atria and the epicardial surface. In spite of its benign nature, the critical location of the tumor inside the heart can lead to lethal arrhythmias and chamber obstruction. Multiple rhabdomyomas are strongly associated with tuberous sclerosis which is associated with mental retardation and epilepsy of variable severity. Ultrasonography as a part of routine prenatal screening, is the best method for the diagnosis of cardiac rhabdomyomas. In the review of articles published in Iran, fetal cardiac rhabdomyoma was not reported. Case presentation: We report a case of cardiac rhabdomyoma on a 24-year-old gravid 1, referred to Day Medical Imaging Center for routine evaluation of fetal abnormalities at 31 weeks of her gestational age. Ultrasonographic examination displayed a homogenous echogenic mass (13×9mm, originating from the left ventricle of the fetal heart. It was a normal pregnancy without any specific complications. Other organs of the fetus were found normal and no cardiac abnormalities were appeared. No Pericardial fluid effusion was found. The parents did not have consanguineous marriage. They did not also have any specific disease such as tuberous sclerosis. Conclusion: The clinical features of cardiac rhabdomyomas vary widely, depending on the location, size, and number of tumors in the heart. Although cardiac rhabdomyoma is a benign tumor in many affected fetuses, an early prenatal diagnosis of the tumor is of great significance in making efficient planning and providing adequate follow up visits of the patients and the complications such as, heart failure and outlet obstruction of cardiac chambers.

  18. Stress distribution among periodontally compromised abutments: A comparative study using three-dimensional finite element analysis

    Directory of Open Access Journals (Sweden)

    Rajkiran Chitumalla


    Full Text Available Aims: The aim of the study was to evaluate the stress distribution patterns in teeth and supporting structures of fixed prosthesis and design modifications in a fixed prosthesis with either normal or reduced bone support of an additional abutment. Study was also undertaken to disprove Ante′s law. Materials and Methods: Main models and variations of main models (modification 1, 2, 3, 4, 5, 6, 7, 8 were subjected to 200 N at angulations of 90° and 15° on functional cusps. Results for each loading were obtained as stress distribution color images and numerical values were recorded. A three-dimensional finite element analysis study of variations of normal models was performed using two finite element softwares, namely PRO-Engineer wildfire version 1.0 manufacturer: Parametric technology corporation, Needham, MA 02494 U.S.A. Results: When periodontal compromised abutment teeth was splinted with an additional abutment an increase of stress was observed in periodontally compromised abutments so an additional abutment is not required. Eventhough the pericemental area of compromised abutments with an additional abutment (canine was more than the combined pericemental area of pontics to be replaced, stress generated was more on abutments. This disproves Ante′s law. Hence, it may be a reference, but should not be the ultimate criterion in determining the number of multiple abutments. Conclusions: When periodontal compromised abutment teeth was splinted with an additional abutment an increase of stress was observed in periodontally compromised abutments so an additional abutment is not required. Even though the pericemental area of compromised abutments with an additional abutment (canine was more than combined pericemental area of pontics to be replaced, stress generated was more on abutments. This disproves Ante′s law. Hence, it may be a reference, but should not be the ultimate criterion in determining the number of multiple abutments.

  19. Clinicopathologic subtypes and compromise of lymph nodes in patients with breast cancer (United States)

    Jaime Jans, B; Nicolás Escudero, M; Dahiana Pulgar, B; Francisco Acevedo, C; César Sánchez, R; Camus, A Mauricio


    Breast cancer (BC) is currently a heterogeneous disease with variations in clinical behaviour. Classification according to subtypes has allowed progress in the individualisation of treatment. The objective of this study is to evaluate the risk of axillary node compromise in patients with BC, according to clinicopathologic subtypes. Materials and methods are a retrospective, descriptive-analytical study. All patients that had undergone surgery for invasive BC were included, with the study of sentinel lymph nodes (SLNs) at Hospital Clínico de la Pontificia Universidad Católica, between May 1999 and December 2012. The results showed 632 patients fulfilled the inclusion criteria, with the median age being 55 years (range: 28–95), and 559 (88.4%) patients presented with estrogen receptor and/or progesterone receptor positive tumours. Luminal A: 246 patients (38.9%), luminal B: 243 (38.4%), luminal not otherwise specified: 70 (11.1%) triple negative (TN): 60 (9.5%) and over expression of epidermal growth factor type 2 receptor (HER2 positive): 13 (2.1%). Luminal tumours displayed a greater risk of metastasis in the SLNs, but this difference was not statistically significant (p = 0.67). TN and HER2 positive tumours presented the greatest proportion of metastatic compromise in non-sentinel lymph nodes (non-SLNs) (57.1% and 50%, respectively). The presence of macrometastasis (MAM) in the SLN was associated with a greater risk of compromise of the non-SLN. Conclusions: Luminal tumours are the most frequent and present a greater proportion of axillary lymph node compromise, without being statistically significant. TN and HER2 positive tumours tend to have a higher axillary compromise; however, this was not statistically significant in either. Only the presence of MAM in SLNs displayed a statistically significantly association in the compromise of non-SLNs. PMID:25114720

  20. Epigenetic regulation in cardiac fibrosis

    Institute of Scientific and Technical Information of China (English)

    Li-Ming; Yu; Yong; Xu


    Cardiac fibrosis represents an adoptive response in the heart exposed to various stress cues. While resolution of the fibrogenic response heralds normalization of heart function, persistent fibrogenesis is usually associated with progressive loss of heart function and eventually heart failure. Cardiac fibrosis is regulated by a myriad of factors that converge on the transcription of genes encoding extracellular matrix proteins, a process the epigenetic machinery plays a pivotal role. In this minireview, we summarize recent advances regarding the epigenetic regulation of cardiac fibrosis focusing on the role of histone and DNA modifications and non-coding RNAs.

  1. Cardiac Involvement in Ankylosing Spondylitis (United States)

    Ozkan, Yasemin


    Ankylosing spondylitis is one of the subgroup of diseases called “seronegative spondyloarthropathy”. Frequently, it affects the vertebral colon and sacroiliac joint primarily and affects the peripheral joints less often. This chronic, inflammatory and rheumatic disease can also affect the extraarticular regions of the body. The extraarticular affections can be ophthalmologic, cardiac, pulmonary or neurologic. The cardiac affection can be 2-10% in all patients. Cardiac complications such as left ventricular dysfunction, aortitis, aortic regurgitation, pericarditis and cardiomegaly are reviewed. PMID:27222669

  2. Acupuncture therapy related cardiac injury. (United States)

    Li, Xue-feng; Wang, Xian


    Cardiac injury is the most serious adverse event in acupuncture therapy. The causes include needling chest points near the heart, the cardiac enlargement and pericardial effusion that will enlarge the projected area on the body surface and make the proper depth of needling shorter, and the incorrect needling method of the points. Therefore, acupuncture practitioners must be familiar with the points of the heart projected area on the chest and the correct needling methods in order to reduce the risk of acupuncture therapy related cardiac injury.

  3. Overview of mitochondrial bioenergetics. (United States)

    Madeira, Vitor M C


    Bioenergetic Science started in seventh century with the pioneer works by Joseph Priestley and Antoine Lavoisier on photosynthesis and respiration, respectively. New developments were implemented by Pasteur in 1860s with the description of fermentations associated to microorganisms, further documented by Buchner brothers who discovered that fermentations also occurred in cell extracts in the absence of living cells. In the beginning of twentieth century, Harden and Young demonstrated that orthophosphate and other heat-resistant compounds (cozymase), later identified as NAD, ADP, and metal ions, were mandatory in the fermentation of glucose. The full glycolysis pathway has been detailed in 1940s with the contributions of Embden, Meyeroff, Parnas, Warburg, among others. Studies on the citric acid cycle started in 1910 (Thunberg) and were elucidated by Krebs et al. in the 1940s. Mitochondrial bioenergetics gained emphasis in the late 1940s and 1950s with the works of Lenhinger, Racker, Chance, Boyer, Ernster, and Slater, among others. The prevalent "chemical coupling hypothesis" of energy conservation in oxidative phosphorylation was challenged and replaced by the "chemiosmotic hypothesis" originally formulated in 1960s by Mitchell and later substantiated and extended to energy conservation in bacteria and chloroplasts, besides mitochondria, with clear-cut identification of molecular proton pumps. After identification of most reactive mechanisms, emphasis has been directed to structure resolution of molecular complex clusters, e.g., cytochrome c oxidase, complex III, complex II, ATP synthase, photosystem I, photosynthetic water splitting center, and energy collecting antennæ of several photosynthetic systems. Modern trends concern to the reactivity of radical and other active species in association with bioenergetic activities. A promising trend concentrates on the cell redox status quantified in terms of redox potentials. In spite of significant development and

  4. Hypoxamirs and Mitochondrial Metabolism (United States)

    Cottrill, Katherine A.; Chan, Stephen Y.


    Abstract Significance: Chronic hypoxia can drive maladaptive responses in numerous organ systems, leading to a multitude of chronic mammalian diseases. Oxygen homeostasis is intimately linked with mitochondrial metabolism, and dysfunction in these systems can combine to form the backbone of hypoxic-ischemic injury in multiple tissue beds. Increased appreciation of the crucial roles of hypoxia-associated miRNA (hypoxamirs) in metabolism adds a new dimension to our understanding of the regulation of hypoxia-induced disease. Recent Advances: Myriad factors related to glycolysis (e.g., aldolase A and hexokinase II), tricarboxylic acid cycle function (e.g., glutaminase and iron-sulfur cluster assembly protein 1/2), and apoptosis (e.g., p53) have been recently implicated as targets of hypoxamirs. In addition, several hypoxamirs have been implicated in the regulation of the master transcription factor of hypoxia, hypoxia-inducible factor-1α, clarifying how the cellular program of hypoxia is sustained and resolved. Critical Issues: Central to the discussion of metabolic change in hypoxia is the Warburg effect, a shift toward anaerobic metabolism that persists after normal oxygen levels have been restored. Many newly discovered targets of hypoxia-driven microRNA converge on pathways known to be involved in this pathological phenomenon and the apoptosis-resistant phenotype associated with it. Future Directions: The often synergistic functions of miRNA may make them ideal therapeutic targets. The use of antisense inhibitors is currently being considered in diseases in which hypoxia and metabolic dysregulation predominate. In addition, exploration of pleiotripic miRNA functions will likely continue to offer unique insights into the mechanistic relationships of their downstream target pathways and associated hypoxic phenotypes. Antioxid. Redox Signal. 21, 1189–1201. PMID:24111795

  5. Cardiac Cytochrome c Oxidase Activity and Contents of Submits 1 and 4 are Altered in Offspring by Low Prenatal Intake by Rat Dams (United States)

    It has been reported previously that the offspring of rat dams consuming low dietary copper (Cu) during pregnancy and lactation experience a deficiency in cardiac cytochrome c oxidase (CCO) characterized by reduced catalytic activity and mitochondrial- and nuclear-subunit content after postnatal day...

  6. Normal cardiac function in mice with supraphysiological cardiac creatine levels. (United States)

    Santacruz, Lucia; Hernandez, Alejandro; Nienaber, Jeffrey; Mishra, Rajashree; Pinilla, Miguel; Burchette, James; Mao, Lan; Rockman, Howard A; Jacobs, Danny O


    Creatine and phosphocreatine levels are decreased in heart failure, and reductions in myocellular phosphocreatine levels predict the severity of the disease and portend adverse outcomes. Previous studies of transgenic mouse models with increased creatine content higher than two times baseline showed the development of heart failure and shortened lifespan. Given phosphocreatine's role in buffering ATP content, we tested the hypothesis whether elevated cardiac creatine content would alter cardiac function under normal physiological conditions. Here, we report the creation of transgenic mice that overexpress the human creatine transporter (CrT) in cardiac muscle under the control of the α-myosin heavy chain promoter. Cardiac transgene expression was quantified by qRT-PCR, and human CrT protein expression was documented on Western blots and immunohistochemistry using a specific anti-CrT antibody. High-energy phosphate metabolites and cardiac function were measured in transgenic animals and compared with age-matched, wild-type controls. Adult transgenic animals showed increases of 5.7- and 4.7-fold in the content of creatine and free ADP, respectively. Phosphocreatine and ATP levels were two times as high in young transgenic animals but declined to control levels by the time the animals reached 8 wk of age. Transgenic mice appeared to be healthy and had normal life spans. Cardiac morphometry, conscious echocardiography, and pressure-volume loop studies demonstrated mild hypertrophy but normal function. Based on our characterization of the human CrT protein expression, creatine and phosphocreatine content, and cardiac morphometry and function, these transgenic mice provide an in vivo model for examining the therapeutic value of elevated creatine content for cardiac pathologies.

  7. Recombinant Mitochondrial Transcription Factor A with N-terminal Mitochondrial Transduction Domain Increases Respiration and Mitochondrial Gene Expression


    Iyer, Shilpa; Thomas, Ravindar R.; Portell, Francisco R.; Dunham, Lisa D.; Quigley, Caitlin K.; Bennett, James P


    We developed a scalable procedure to produce human mitochondrial transcription factor A (TFAM) modified with an N-terminal protein transduction domain (PTD) and mitochondrial localization signal (MLS) that allow it to cross membranes and enter mitochondria through its “mitochondrial transduction domain” (MTD=PTD+MLS). Alexa488-labeled MTD-TFAM rapidly entered the mitochondrial compartment of cybrid cells carrying the G11778A LHON mutation. MTD-TFAM reversibly increased respiration and levels ...

  8. Rcan1-1L overexpression induces mitochondrial autophagy and improves cell survival in angiotensin II-exposed cardiomyocytes

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Hongyan; Li, Yongqiang; Yan, Lijie; Yang, Haitao; Wu, Jintao; Qian, Peng; Li, Bing; Wang, Shanling, E-mail:


    Mitochondrial autophagy is an important adaptive stress response and can be modulated by various key molecules. A previous study found that the regulator of calcineurin 1-1L (Rcan1-1L) may regulate mitochondrial autophagy and cause mitochondria degradation in neurocytes. However, the effect of Rcan1-1L on cardiomyocytes has not been determined. In the present study, we aimed to investigate the role of Rcan1-1L in angiotensin II (Ang II)-exposed human cardiomyocytes. Above all, Human adult cardiac myocytes (HACMs) were exposed to 200 nmol/L Ang II for 4 days. Enhanced H{sub 2}O{sub 2} production, cytochrome C release and mitochondrial permeability were observed in these cells, which were blocked by valsartan. Consistently, Ang II exposure significantly reduced cardiomyocyte viability. However, transfection of Rcan1-1L vector promoted cell viability and ameliorated the apoptosis caused by Ang II. Rcan1-1L clearly promoted mitochondrial autophagy in HACMs, with elevated autophagy protein (ATG) 5 and light chain 3 (LC3) expression. Transient mitochondrial biogenesis and reduced cytochrome C release was also induced by Rcan1-1L. Additionally, Rcan1-1L significantly inhibited calcineurin/nuclear factor of activated T cells (NFAT) signaling. We thus conclude that Rcan1-1L may play a protective role in Ang II-treated cardiomyocytes through the induction of mitochondrial autophagy, and may be an alternative method of cardiac protection. - Highlights: • Transfection of Rcan1-1L into HACMs promoted cell viability and reduced apoptosis. • Transfection of Rcan1-1L promoted mitochondrial autophagy in HACMs. • Rcan1-1L inhibited the calcineurin/nuclear factor of activated T cells signaling.

  9. The Leptin Paradox-A Treacherous Art in cardiac sequelae of obesity

    Institute of Scientific and Technical Information of China (English)



    Leptin is the first identified obese gene product which participates in the regulation of food intake, energy expenditure, glucose and lipid metabolism. Leptin initiates both hypertrophic and antihypertrophic effects on hearts in addition to its cardiac depressant effect. Circulating leptin levels correlate with the body mass index (BMI) and total amount of body fat, which may be associated with changes of cardiac morphology and function. It has been shown that cardiac function is present in both hyperleptinemic (db/db) and hypoleptinemic (ob/ob) mouse models. Leptin replenishment reconciles the compromised myocardial function in ob/ob mice, indicating the premises of leptin on heart function. Interestingly, elevated plasma leptin levels may trigger leptin resistance and serve as an independent risk factor for cardiovascular diseases. Therefore, physiological range of leptin is essential tor normal cardiac geometry and function whereas disrupted leptin signaling (hyper-and hypoleptinemia) results in functional and morphological aberrations leading to heart problem. Given that human obesity is a syndrome of leptin resistance, which is unlikely amenable to leptin treatment, the identification of novel parallel signal transduction pathways is of particular therapeutic value for obesity-associated cardiac dysfunction.

  10. New redox-related arrows in the arsenal of cardiac disease treatment. (United States)

    Kirk, Jonathan A; Paolocci, Nazareno


    While great strides have been made to improve the poor prognosis with cardiac disease, heart failure in particular, cardiac affections still remain the most prevalent, difficult-to-treat, and costly human pathologies in the western world. At rest, the heart produces a significant oxidative environment inside diverse cell compartments, due to its high-energy demand. Cardiac cells have an exquisite control system to deal with this constant redox stress. However, persistent hemodynamic alterations can compromise these mechanisms, fueling further myocardial redox imbalance and dysfunction. Still, this would be a one-sided and incomplete view, because the physiological role of reactive oxygen species (ROS) should be considered as well. Indeed, ROS are multipurpose agents, serving signaling and cell defense tasks too, and, similar to antioxidants, these functions can be highly compartmentalized within the cell. The present Forum was designed to collect cutting-edge research concerning when and how to effectively counter excessive oxidative burden to preserve cardiac structure and/or to improve function, under conditions of ordinary or extraordinary stress. Another major objective was to unravel old and new intersections between different myocardial processes by which ROS may act as "on" or "off" switches, and in doing so, dictating function, always with an eye on possible, immediate therapeutic applications, as suggested by the title of the Forum itself, that is, Cardiac Therapeutics.

  11. The Impact of Age-Related Dysregulation of the Angiotensin System on Mitochondrial Redox Balance

    Directory of Open Access Journals (Sweden)

    Ramya eVajapey


    Full Text Available Aging is associated with the accumulation of various deleterious changes in cells. According to the free radical and mitochondrial theory of aging, mitochondria initiate most of the deleterious changes in aging and govern life span. The failure of mitochondrial reduction-oxidation (redox homeostasis and the formation of excessive free radicals are tightly linked to dysregulation in the Renin Angiotensin System (RAS. A main rate-controlling step in RAS is renin, an enzyme that hydrolyzes angiotensinogen to generate angiotensin I. Angiotensin I is further converted to Angiotensin II (Ang II by angiotensin-converting enzyme (ACE. Ang II binds with equal affinity to two main angiotensin receptors—type 1 (AT1R and type 2 (AT2R. The binding of Ang II to AT1R activates NADPH oxidase, which leads to increased generation of cytoplasmic reactive oxygen species (ROS. This Ang II-AT1R–NADPH-ROS signal triggers the opening of mitochondrial KATP channels and mitochondrial ROS production in a positive feedback loop. Furthermore, RAS has been implicated in the decrease of many of ROS scavenging enzymes, thereby leading to detrimental levels of free radicals in the cell.AT2R is less understood, but evidence supports an anti-oxidative and mitochondria-protective function for AT2R. The overlap between age related changes in RAS and mitochondria, and the consequences of this overlap on age-related diseases are quite complex. RAS dysregulation has been implicated in many pathological conditions due to its contribution to mitochondrial dysfunction. Decreased age-related, renal and cardiac mitochondrial dysfunction was seen in patients treated with angiotensin receptor blockers. The aim of this review is to: (a report the most recent information elucidating the role of RAS in mitochondrial redox hemostasis and (b discuss the effect of age-related activation of RAS on generation of free radicals.

  12. Autism Spectrum Disorder and Mitochondrial Disease (United States)

    ... Is there a relationship between mitochondrial disease and autism? A: A child with a mitochondrial disease: may ... something else. Q: Is there a relationship between autism and encephalopathy? A: Most children with an autism ...

  13. Mitochondrial DNA and Cancer Epidemiology Workshop (United States)

    A workshop to review the state-of-the science in the mitochondrial DNA field and its use in cancer epidemiology, and to develop a concept for a research initiative on mitochondrial DNA and cancer epidemiology.

  14. Vitelliform macular degeneration associated with mitochondrial myopathy.


    Modi, G; Heckman, J M; Saffer, D


    A patient with mitochondrial myopathy is described. Examination of his fundus revealed bilateral vitelliform degeneration of the maculae. This lesion is a focal abnormality of the retinal pigment epithelium and may be a manifestation of the underlying mitochondrial disease.

  15. Mitochondrial maintenance failure in aging and role of sexual dimorphism


    Tower, John


    Gene expression changes during aging are partly conserved across species, and suggest that oxidative stress, inflammation and proteotoxicity result from mitochondrial malfunction and abnormal mitochondrial-nuclear signaling. Mitochondrial maintenance failure may result from trade-offs between mitochondrial turnover versus growth and reproduction, sexual antagonistic pleiotropy and genetic conflicts resulting from uni-parental mitochondrial transmission, as well as mitochondrial and nuclear mu...

  16. Macroautophagy and Cell Responses Related to Mitochondrial Dysfunction, Lipid Metabolism and Unconventional Secretion of Proteins (United States)

    Demine, Stéphane; Michel, Sébastien; Vannuvel, Kayleen; Wanet, Anaïs; Renard, Patricia; Arnould, Thierry


    Macroautophagy has important physiological roles and its cytoprotective or detrimental function is compromised in various diseases such as many cancers and metabolic diseases. However, the importance of autophagy for cell responses has also been demonstrated in many other physiological and pathological situations. In this review, we discuss some of the recently discovered mechanisms involved in specific and unspecific autophagy related to mitochondrial dysfunction and organelle degradation, lipid metabolism and lipophagy as well as recent findings and evidence that link autophagy to unconventional protein secretion. PMID:24710422

  17. Macroautophagy and Cell Responses Related to Mitochondrial Dysfunction, Lipid Metabolism and Unconventional Secretion of Proteins

    Directory of Open Access Journals (Sweden)

    Thierry Arnould


    Full Text Available Macroautophagy has important physiological roles and its cytoprotective or detrimental function is compromised in various diseases such as many cancers and metabolic diseases. However, the importance of autophagy for cell responses has also been demonstrated in many other physiological and pathological situations. In this review, we discuss some of the recently discovered mechanisms involved in specific and unspecific autophagy related to mitochondrial dysfunction and organelle degradation, lipid metabolism and lipophagy as well as recent findings and evidence that link autophagy to unconventional protein secretion.

  18. Mitochondrial and performance adaptations to exercise training in mice lacking skeletal muscle LKB1. (United States)

    Tanner, Colby B; Madsen, Steven R; Hallowell, David M; Goring, Darren M J; Moore, Timothy M; Hardman, Shalene E; Heninger, Megan R; Atwood, Daniel R; Thomson, David M


    LKB1 and its downstream targets of the AMP-activated protein kinase family are important regulators of many aspects of skeletal muscle cell function, including control of mitochondrial content and capillarity. LKB1 deficiency in skeletal and cardiac muscle (mLKB1-KO) greatly impairs exercise capacity. However, cardiac dysfunction in that genetic model prevents a clear assessment of the role of skeletal muscle LKB1 in the observed effects. Our purposes here were to determine whether skeletal muscle-specific knockout of LKB1 (skmLKB1-KO) decreases exercise capacity and mitochondrial protein content, impairs accretion of mitochondrial proteins after exercise training, and attenuates improvement in running performance after exercise training. We found that treadmill and voluntary wheel running capacity was reduced in skmLKB1-KO vs. control (CON) mice. Citrate synthase activity, succinate dehydrogenase activity, and pyruvate dehydrogenase kinase content were lower in KO vs. CON muscles. Three weeks of treadmill training resulted in significantly increased treadmill running performance in both CON and skmLKB1-KO mice. Citrate synthase activity increased significantly with training in both genotypes, but protein content and activity for components of the mitochondrial electron transport chain increased only in CON mice. Capillarity and VEGF protein was lower in skmLKB1-KO vs. CON muscles, but VEGF increased with training only in skmLKB1-KO. Three hours after an acute bout of muscle contractions, PGC-1α, cytochrome c, and VEGF gene expression all increased in CON but not skmLKB1-KO muscles. Our findings indicate that skeletal muscle LKB1 is required for accretion of some mitochondrial proteins but not for early exercise capacity improvements with exercise training.

  19. Recent developments in cardiac pacing. (United States)

    Rodak, D J


    Indications for cardiac pacing continue to expand. Pacing to improve functional capacity, which is now common, relies on careful patient selection and technical improvements, such as complex software algorithms and diagnostic capabilities.

  20. Robotic Applications in Cardiac Surgery

    Directory of Open Access Journals (Sweden)

    Alan P. Kypson


    Full Text Available Traditionally, cardiac surgery has been performed through a median sternotomy, which allows the surgeon generous access to the heart and surrounding great vessels. As a paradigm shift in the size and location of incisions occurs in cardiac surgery, new methods have been developed to allow the surgeon the same amount of dexterity and accessibility to the heart in confined spaces and in a less invasive manner. Initially, long instruments without pivot points were used, however, more recent robotic telemanipulation systems have been applied that allow for improved dexterity, enabling the surgeon to perform cardiac surgery from a distance not previously possible. In this rapidly evolving field, we review the recent history and clinical results of using robotics in cardiac surgery.

  1. Polyunsaturated fatty acids incorporation into cardiolipin in H9c2 cardiac myoblast. (United States)

    Ting, Hsiu-Chi; Chao, Yu-Jen; Hsu, Yuan-Hao Howard


    Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), known as ω-3 polyunsaturated fatty acid (PUFA), are common nutrients in daily food intake and have been shown to prevent cardiovascular disease and improve cardiac functions. Cardiolipin is a mitochondrial phospholipid necessary for maintaining physiological function of mitochondria. Several studies have indicated that the cardiolipin acyl chain compositions affect the function of cardiolipin and mitochondria. Here, we investigated the structural changes of cardiolipin after DHA and EPA supplementation and compared them to arachidonic acid (AA) treatment. H9c2 cardiac myoblast was used as a cell model, and cardiolipin species was monitored and identified via LC-MS and MS/MS. Our results showed distinct mass envelopes of cardiolipin with the same carbon number but different double bonds in mass spectrum. There were 116 cardiolipin species with 36 distinct mass in 6 mass envelopes identified by MS/MS. Three days of PUFA treatment resulted in decreases of low-molecular-weight cardiolipin and increases of high-molecular-weight cardiolipin, suggesting the incorporation of exogenous DHA, EPA and AA into mitochondrial cardiolipin. PUFA incorporation was further verified by MS/MS analysis. More importantly, we found that DHA supplementation elevated the percent content of less unsaturated cardiolipin species and highly unsaturated cardiolipin species, containing ω-3 fatty acyl chains, indicating a ω-3 fatty acid incorporation mechanism with peroxidation protection. Our results indicate that PUFA supplementation differentially perturbed the fatty acyl chain compositions in the mitochondrial cardiolipin in the H9c2 cardiac myoblast, suggesting that mitochondrial membrane and the function of mitochondria are susceptible to exogenous lipid species.

  2. Ethics of mitochondrial therapy for deafness. (United States)

    Legge, Michael; Fitzgerald, Ruth P


    Mitochondrial therapy may provide the relief to many families with inherited mitochondrial diseases. However, it also has the potential for use in non-fatal disorders such as inherited mitochondrial deafness, providing an option for correction of the deafness using assisted reproductive technology. In this paper we discuss the potential for use in correcting mitochondrial deafness and consider some of the issues for the deaf community.

  3. Cardiac manifestations in systemic sclerosis

    Institute of Scientific and Technical Information of China (English)

    Sevdalina; Lambova


    Primary cardiac involvement, which develops as a direct consequence of systemic sclerosis(SSc), may manifest as myocardial damage, fibrosis of the conduction system, pericardial and, less frequently, as valvular disease. In addition, cardiac complications in SSc may develop as a secondary phenomenon due to pulmonary arterial hypertension and kidney pathology. The prevalence of primary cardiac involvement in SSc is variable and difficult to determine because of the diversity of cardiac manifestations, the presence of subclinical periods, the type of diagnostic tools applied, and the diversity of patient populations. When clinically manifested, cardiac involvement is thought to be an important prognostic factor. Profound microvascular disease is a pathognomonic feature of SSc, as both vasospasm and structural alterations are present. Such alterations are thought to predict macrovascular atherosclerosis over time. There are contradictory reports regarding the prevalence of atherosclerosis in SSc. According to some authors, the prevalence of atherosclerosis of the large epicardial coronary arteries is similar to that of the general population, in contrast with other rheumatic diseases such as rheumatoid arthritis and systemic lupus erythematosus. However, the level of inflammation in SSc is inferior. Thus, the atherosclerotic process may not be as aggressive and not easily detectable in smaller studies. Echocardiography(especially tissue Doppler imaging), single-photon emission computed tomography, magnetic resonance imaging and cardiac computed tomography are sensitive techniques for earlier detection of both structural and functional scleroderma-related cardiac pathologies. Screening for subclinical cardiac involvement via modern, sensitive tools provides an opportunity for early diagnosis and treatment, which is of crucial importance for a positive outcome.

  4. Cardiac transplantation in Friedreich ataxia. (United States)

    Yoon, Grace; Soman, Teesta; Wilson, Judith; George, Kristen; Mital, Seema; Dipchand, Anne I; McCabe, Jane; Logan, William; Kantor, Paul


    In this article, we describe a 14-year-old boy with a confirmed diagnosis of Friedreich ataxia who underwent cardiac transplantation for left ventricular failure secondary to dilated cardiomyopathy with restrictive physiology. His neurological status prior to transplantation reflected early signs of neurological disease, with evidence of dysarthria, weakness, mild gait impairment, and limb ataxia. We review the ethical issues considered during the process leading to the decision to offer cardiac transplantation.

  5. Cardiac Transplantation in Friedreich Ataxia


    Yoon, Grace; Soman, Teesta; Wilson, Judith; George, Kristen; Mital, Seema; Dipchand, Anne I; McCabe, Jane; Logan, William; Kantor, Paul


    In this paper, we describe a 14-year-old boy with a confirmed diagnosis of Friedreich ataxia who underwent cardiac transplantation for left ventricular failure secondary to dilated cardiomyopathy with restrictive physiology. His neurological status prior to transplantation reflected early signs of neurologic disease, with evidence of dysarthria, weakness, mild gait impairment, and limb ataxia. We review the ethical issues considered during the process leading to the decision to offer cardiac ...

  6. Mitochondrial myopathy and myoclonic epilepsy

    Directory of Open Access Journals (Sweden)

    Walter O. Arruda


    Full Text Available The authors describe a family (mother, son and two daughters with mitochondrial myopathy. The mother was asymptomatic. Two daughters had lactic acidosis and myoclonic epilepsy, mild dementia, ataxia, weakness and sensory neuropathy. The son suffered one acute hemiplegic episode due to an ischemic infarct in the right temporal region. All the patients studied had hypertension. EEG disclosed photomyoclonic response in the proband patient. Muscle biopsy disclosed ragged-red fibers and abnormal mitochondria by electron microscopy. Biochemical analysis showed a defect of cytochrome C oxidase in mitochondria isolated from skeletal muscle. Several clinical and genetic aspects of the mitochondrial encephalomyopathies are discussed.

  7. Hypoxic regulation of hand1 controls the fetal-neonatal switch in cardiac metabolism.

    Directory of Open Access Journals (Sweden)

    Ross A Breckenridge


    Full Text Available Cardiomyocytes are vulnerable to hypoxia in the adult, but adapted to hypoxia in utero. Current understanding of endogenous cardiac oxygen sensing pathways is limited. Myocardial oxygen consumption is determined by regulation of energy metabolism, which shifts from glycolysis to lipid oxidation soon after birth, and is reversed in failing adult hearts, accompanying re-expression of several "fetal" genes whose role in disease phenotypes remains unknown. Here we show that hypoxia-controlled expression of the transcription factor Hand1 determines oxygen consumption by inhibition of lipid metabolism in the fetal and adult cardiomyocyte, leading to downregulation of mitochondrial energy generation. Hand1 is under direct transcriptional control by HIF1α. Transgenic mice prolonging cardiac Hand1 expression die immediately following birth, failing to activate the neonatal lipid metabolising gene expression programme. Deletion of Hand1 in embryonic cardiomyocytes results in premature expression of these genes. Using metabolic flux analysis, we show that Hand1 expression controls cardiomyocyte oxygen consumption by direct transcriptional repression of lipid metabolising genes. This leads, in turn, to increased production of lactate from glucose, decreased lipid oxidation, reduced inner mitochondrial membrane potential, and mitochondrial ATP generation. We found that this pathway is active in adult cardiomyocytes. Up-regulation of Hand1 is protective in a mouse model of myocardial ischaemia. We propose that Hand1 is part of a novel regulatory pathway linking cardiac oxygen levels with oxygen consumption. Understanding hypoxia adaptation in the fetal heart may allow development of strategies to protect cardiomyocytes vulnerable to ischaemia, for example during cardiac ischaemia or surgery.

  8. Mitochondrial dysfunction in autism. (United States)

    Legido, Agustín; Jethva, Reena; Goldenthal, Michael J


    Using data of the current prevalence of autism as 200:10,000 and a 1:2000 incidence of definite mitochondrial (mt) disease, if there was no linkage of autism spectrum disorder (ASD) and mt disease, it would be expected that 1 in 110 subjects with mt disease would have ASD and 1 in 2000 individuals with ASD would have mt disease. The co-occurrence of autism and mt disease is much higher than these figures, suggesting a possible pathogenetic relationship. Such hypothesis was initially suggested by the presence of biochemical markers of abnormal mt metabolic function in patients with ASD, including elevation of lactate, pyruvate, or alanine levels in blood, cerebrospinal fluid, or brain; carnitine level in plasma; and level of organic acids in urine, and by demonstrating impaired mt fatty acid β-oxidation. More recently, mtDNA genetic mutations or deletions or mutations of nuclear genes regulating mt function have been associated with ASD in patients or in neuropathologic studies on the brains of patients with autism. In addition, the presence of dysfunction of the complexes of the mt respiratory chain or electron transport chain, indicating abnormal oxidative phosphorylation, has been reported in patients with ASD and in the autopsy samples of brains. Possible pathogenetic mechanisms linking mt dysfunction and ASD include mt activation of the immune system, abnormal mt Ca(2+) handling, and mt-induced oxidative stress. Genetic and epigenetic regulation of brain development may also be disrupted by mt dysfunction, including mt-induced oxidative stress. The role of the purinergic system linking mt dysfunction and ASD is currently under investigation. In summary, there is genetic and biochemical evidence for a mitochondria (mt) role in the pathogenesis of ASD in a subset of children. To determine the prevalence and type of genetic and biochemical mt defects in ASD, there is a need for further research using the latest genetic technology such as next

  9. Efficiency of mitochondrially targeted gallic acid in reducing brain mitochondrial oxidative damage. (United States)

    Parihar, P; Jat, D; Ghafourifar, P; Parihar, M S


    Oxidative stress is associated with mitochondrial impairments. Supplying mitochondria with potent antioxidants can reduce oxidative stress—induced mitochondrial impairment. Gallic acid can be used to reduce oxidative burden in mitochondria. In order to increase the bioavailability of gallic acid inside the mitochondria we synthesized mitochondrially targeted gallic acid and explored its preventive effects against sodium nitroprusside induced oxidative stress in isolated mitochondria. Our observations revealed an increase in oxidative stress,decrease in reduced glutathione in mitochondria and increase in the mitochondrial permeability pore transition due to sodium nitroprusside treatment. Pre—treatment of gallic acid and mitochondrially targeted gallic acid to sodium nitroprusside treated mitochondria not only significantly reduced the oxidative stress but also prevented mitochondrial permeability pore transition to a significant difference. Mitochondrially targeted gallic acid was found more effective in reducing oxidative stress and mitochondrial permeability pore transition than gallic acid. We conclude that mitochondrially targeted gallic acid can be used for preventing mitochondrial impairment caused by oxidative stress.

  10. [Stem cells and cardiac regeneration]. (United States)

    Perez Millan, Maria Ines; Lorenti, Alicia


    Stem cells are defined by virtue of their functional attributes: absence of tissue specific differentitated markers, capable of proliferation, able to self-maintain the population, able to produce a large number of differentiated, functional progeny, able to regenerate the tissue after injury. Cell therapy is an alternative for the treatment of several diseases, like cardiac diseases (cell cardiomyoplasty). A variety of stem cells could be used for cardiac repair: from cardiac and extracardiac sources. Each cell type has its own profile of advantages, limitations, and practicability issues in specific clinical settings. Differentiation of bone marrow stem cells to cardiomyocyte-like cells have been observed under different culture conditions. The presence of resident cardiac stem cell population capable of differentiation into cardiomyocyte or vascular lineage suggests that these cells could be used for cardiac tissue repair, and represent a great promise for clinical application. Stem cells mobilization by cytokines may also offer a strategy for cardiac regeneration. The use of stem cells (embryonic and adult) may hold the key to replacing cells lost in many devastating diseases. This potential benefit is a major focus for stem cell research.

  11. Cardiac Regeneration and Stem Cells. (United States)

    Zhang, Yiqiang; Mignone, John; MacLellan, W Robb


    After decades of believing the heart loses the ability to regenerate soon after birth, numerous studies are now reporting that the adult heart may indeed be capable of regeneration, although the magnitude of new cardiac myocyte formation varies greatly. While this debate has energized the field of cardiac regeneration and led to a dramatic increase in our understanding of cardiac growth and repair, it has left much confusion in the field as to the prospects of regenerating the heart. Studies applying modern techniques of genetic lineage tracing and carbon-14 dating have begun to establish limits on the amount of endogenous regeneration after cardiac injury, but the underlying cellular mechanisms of this regeneration remained unclear. These same studies have also revealed an astonishing capacity for cardiac repair early in life that is largely lost with adult differentiation and maturation. Regardless, this renewed focus on cardiac regeneration as a therapeutic goal holds great promise as a novel strategy to address the leading cause of death in the developed world.

  12. Cardiac imaging. A multimodality approach

    Energy Technology Data Exchange (ETDEWEB)

    Thelen, Manfred [Johannes Gutenberg University Hospital, Mainz (Germany); Erbel, Raimund [University Hospital Essen (Germany). Dept. of Cardiology; Kreitner, Karl-Friedrich [Johannes Gutenberg University Hospital, Mainz (Germany). Clinic and Polyclinic for Diagnostic and Interventional Radiology; Barkhausen, Joerg (eds.) [University Hospital Schleswig-Holstein, Luebeck (Germany). Dept. of Radiology and Nuclear Medicine


    An excellent atlas on modern diagnostic imaging of the heart Written by an interdisciplinary team of experts, Cardiac Imaging: A Multimodality Approach features an in-depth introduction to all current imaging modalities for the diagnostic assessment of the heart as well as a clinical overview of cardiac diseases and main indications for cardiac imaging. With a particular emphasis on CT and MRI, the first part of the atlas also covers conventional radiography, echocardiography, angiography and nuclear medicine imaging. Leading specialists demonstrate the latest advances in the field, and compare the strengths and weaknesses of each modality. The book's second part features clinical chapters on heart defects, endocarditis, coronary heart disease, cardiomyopathies, myocarditis, cardiac tumors, pericardial diseases, pulmonary vascular diseases, and diseases of the thoracic aorta. The authors address anatomy, pathophysiology, and clinical features, and evaluate the various diagnostic options. Key features: - Highly regarded experts in cardiology and radiology off er image-based teaching of the latest techniques - Readers learn how to decide which modality to use for which indication - Visually highlighted tables and essential points allow for easy navigation through the text - More than 600 outstanding images show up-to-date technology and current imaging protocols Cardiac Imaging: A Multimodality Approach is a must-have desk reference for cardiologists and radiologists in practice, as well as a study guide for residents in both fields. It will also appeal to cardiac surgeons, general practitioners, and medical physicists with a special interest in imaging of the heart. (orig.)

  13. 38 CFR 1.955 - Regional office Committees on Waivers and Compromises. (United States)


    ... OF VETERANS AFFAIRS GENERAL PROVISIONS Referrals to Gao, Department of Justice, Or Irs § 1.955... and Compromises is the responsibility of the station's Fiscal Officer. However, the station Director... than the Fiscal Officer, whenever the Director determines that such reassignment is appropriate....

  14. 76 FR 15212 - Redelegation of Authority to Compromise and Close Civil Claims (United States)


    ..., Tax Division, Department of Justice, Washington, DC 20530, (202) 307-6567. SUPPLEMENTARY INFORMATION... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF JUSTICE 28 CFR Part 0 Redelegation of Authority to Compromise and Close Civil Claims AGENCY: Department of...

  15. Effects of Warmth of Interaction, Accuracy of Understanding, and the Proposal of Compromises on Listener's Behavior (United States)

    Johnson, David W.


    The results of this experiment demonstrate a causal relationship (a) between the expressed accuracy of understanding and the proposal of compromises and the induction of cooperation in a negotiation situation and (b) between the expressed warmth and degree of favorableness of interpersonal attitudes, thus giving support to the efficacy of Rogerian…

  16. 15 CFR 19.7 - When will Commerce entities compromise a Commerce debt? (United States)


    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false When will Commerce entities compromise a Commerce debt? 19.7 Section 19.7 Commerce and Foreign Trade Office of the Secretary of Commerce COMMERCE DEBT COLLECTION Procedures To Collect Commerce Debts § 19.7 When will Commerce entities...

  17. Acute abdomen in a patient with paraesophageal hernia, resulting in acute compromised respiratory function

    DEFF Research Database (Denmark)

    Mekhael, Mira Rober; El-Hussuna, Alaa


    INTRODUCTION: We present a case of acute abdomen, causing increased intra-abdominal pressure, leading to further herniation of an existing paraesophageal hernia, and consequently acute compromised respiratory function. This acute respiratory complication to a paraesophageal hernia has not previou......INTRODUCTION: We present a case of acute abdomen, causing increased intra-abdominal pressure, leading to further herniation of an existing paraesophageal hernia, and consequently acute compromised respiratory function. This acute respiratory complication to a paraesophageal hernia has...... if complicated by acute abdomen. These patients could benefit from elective hernia repair, rather than watchful waiting, as it would eliminate pulmonary symptoms and prevent similar cases. Patients monitored using watchful waiting should be informed that acute abdomen could cause acute compromised respiratory...... function. CONCLUSION: Any case of acute abdomen causing high intra-abdominal pressure could potentially cause further herniation of an existing paraesophageal hernia, resulting in acute compromised respiratory function. In patients known to have a paraesophageal hernia, similar cases should be suspected...

  18. Advanced medical life support procedures in vitally compromised children by a helicopter emergency medical service.

    NARCIS (Netherlands)

    Gerritse, B.M.; Schalkwijk, A.; Pelzer, B.J.; Scheffer, G.J.; Draaisma, J.M.T.


    BACKGROUND: To determine the advanced life support procedures provided by an Emergency Medical Service (EMS) and a Helicopter Emergency Medical Service (HEMS) for vitally compromised children. Incidence and success rate of several procedures were studied, with a distinction made between procedures r

  19. 7 CFR 1956.66 - Compromise and adjustment of nonjudgment debts. (United States)


    ...'s essential family living expenses, and farm or business operation expenses necessary to continue... SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE AGENCY, DEPARTMENT... Programs and Multi-Family Housing § 1956.66 Compromise and adjustment of nonjudgment debts....

  20. 13 CFR 107.1710 - SBA authority to collect or compromise its claims. (United States)


    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false SBA authority to collect or compromise its claims. 107.1710 Section 107.1710 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION SMALL BUSINESS INVESTMENT COMPANIES SBA Financial Assistance for Licensees (Leverage)...