scholarly journals Cell-Permeable Succinate Increases Mitochondrial Membrane Potential and Glycolysis in Leigh Syndrome Patient Fibroblasts

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2255
Author(s):  
Ajibola B. Bakare ◽  
Raj R. Rao ◽  
Shilpa Iyer
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Tricarboxylic Acid Cycle ◽  
Mitochondrial Disorder ◽  
Leigh Syndrome ◽  
High Energy ◽  
Therapeutic Effects ◽  
Organ Systems

Mitochondrial disorders represent a large group of severe genetic disorders mainly impacting organ systems with high energy requirements. Leigh syndrome (LS) is a classic example of a mitochondrial disorder resulting from pathogenic mutations that disrupt oxidative phosphorylation capacities. Currently, evidence-based therapy directed towards treating LS is sparse. Recently, the cell-permeant substrates responsible for regulating the electron transport chain have gained attention as therapeutic agents for mitochondrial diseases. We explored the therapeutic effects of introducing tricarboxylic acid cycle (TCA) intermediate substrate, succinate, as a cell-permeable prodrug NV118, to alleviate some of the mitochondrial dysfunction in LS. The results suggest that a 24-hour treatment with prodrug NV118 elicited an upregulation of glycolysis and mitochondrial membrane potential while inhibiting intracellular reactive oxygen species in LS cells. The results from this study suggest an important role for TCA intermediates for treating mitochondrial dysfunction in LS. We show, here, that NV118 could serve as a therapeutic agent for LS resulting from mutations in mtDNA in complex I and complex V dysfunctions.

scholarly journals Alpha-Tocotrienol Prevents Oxidative Stress-Mediated Post-Translational Cleavage of Bcl-xL in Primary Hippocampal Neurons

2019 ◽  
Vol 21 (1) ◽  
pp. 220 ◽  
Author(s):  
Han-A Park ◽  
Nelli Mnatsakanyan ◽  
Katheryn Broman ◽  
Abigail U. Davis ◽  
Jordan May ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Function ◽  
Hippocampal Neurons ◽  
Mitochondrial Membrane ◽  
Antioxidant Properties ◽  
B Cell Lymphoma ◽  
Atp Depletion ◽  
Primary Hippocampal Neurons

B-cell lymphoma-extra large (Bcl-xL) is an anti-apoptotic member of the Bcl2 family of proteins, which supports neurite outgrowth and neurotransmission by improving mitochondrial function. During excitotoxic stimulation, however, Bcl-xL undergoes post-translational cleavage to ∆N-Bcl-xL, and accumulation of ∆N-Bcl-xL causes mitochondrial dysfunction and neuronal death. In this study, we hypothesized that the generation of reactive oxygen species (ROS) during excitotoxicity leads to formation of ∆N-Bcl-xL. We further proposed that the application of an antioxidant with neuroprotective properties such as α-tocotrienol (TCT) will prevent ∆N-Bcl-xL-induced mitochondrial dysfunction via its antioxidant properties. Primary hippocampal neurons were treated with α-TCT, glutamate, or a combination of both. Glutamate challenge significantly increased cytosolic and mitochondrial ROS and ∆N-Bcl-xL levels. ∆N-Bcl-xL accumulation was accompanied by intracellular ATP depletion, loss of mitochondrial membrane potential, and cell death. α-TCT prevented loss of mitochondrial membrane potential in hippocampal neurons overexpressing ∆N-Bcl-xL, suggesting that ∆N-Bcl-xL caused the loss of mitochondrial function under excitotoxic conditions. Our data suggest that production of ROS is an important cause of ∆N-Bcl-xL formation and that preventing ROS production may be an effective strategy to prevent ∆N-Bcl-xL-mediated mitochondrial dysfunction and thus promote neuronal survival.

Glutamine protects mitochondrial structure and function in oxygen toxicity

2001 ◽  
Vol 280 (4) ◽  
pp. L779-L791 ◽  
Author(s):  
Shama Ahmad ◽  
Carl W. White ◽  
Ling-Yi Chang ◽  
Barbara K. Schneider ◽  
Corrie B. Allen
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Tricarboxylic Acid Cycle ◽  
A549 Cells ◽  
Oxygen Toxicity ◽  
Cycle Enzyme ◽  
Glutamine Deprivation ◽  
And Function ◽  
Dose Dependent Increase

Glutamine is an important mitochondrial substrate implicated in the protection of cells from oxidant injury, but the mechanisms of its action are incompletely understood. Human pulmonary epithelial-like (A549) cells were exposed to 95% O2 for 4 days in the absence and presence of glutamine. Cell proliferation in normoxia was dependent on glutamine, and glutamine deprivation markedly accelerated cell death in hyperoxia. Glutamine significantly increased cellular ATP levels in normoxia and prevented the loss of ATP in hyperoxia seen in glutamine-deprived cells. Mitochondrial membrane potential as assessed by flow cytometry with chloromethyltetramethylrosamine was increased by glutamine in hyperoxia-exposed A549 cells, and a glutamine dose-dependent increase in mitochondrial membrane potential was detected. Glutamine-supplemented, hyperoxia-exposed cells had a higher O2 consumption rate and GSH content. Electron and fluorescence microscopy revealed that, in hyperoxia, glutamine protected cellular structures, especially mitochondria, from damage. In hyperoxia, activity of the tricarboxylic acid cycle enzyme α-ketoglutarate dehydrogenase was partially protected by its indirect substrate, glutamine, indicating a mechanism of mitochondrial protection.

Model of β-cell mitochondrial calcium handling and electrical activity. II. Mitochondrial variables

1998 ◽  
Vol 274 (4) ◽  
pp. C1174-C1184 ◽  
Author(s):  
Gerhard Magnus ◽  
Joel Keizer
Keyword(s):  
Membrane Potential ◽  
Electrical Activity ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Adenine Nucleotide ◽  
Tricarboxylic Acid Cycle ◽  
Calcium Handling ◽  
Β Cell ◽  
Futile Cycle ◽  
Cyclic Changes

In the preceding article [ Am. J. Physiol. 274 ( Cell Physiol. 43): C1158–C1173, 1998], we describe the development of a kinetic model for the interaction of mitochondrial Ca2+ handling and electrical activity in the pancreatic β-cell. Here we describe further results of those simulations, focusing on mitochondrial variables, the rate of respiration, and fluxes of metabolic intermediates as a function of d-glucose concentration. Our simulations predict relatively smooth increases of O2consumption, adenine nucleotide transport, oxidative phosphorylation, and ATP production by the tricarboxylic acid cycle asd-glucose concentrations are increased from basal to 20 mM. On the other hand, we find that the active fraction of pyruvate dehydrogenase saturates, due to increases in matrix Ca2+, near the onset of bursting electrical activity and that the NADH/NAD+ ratio in the mitochondria increases by roughly an order of magnitude as glucose concentrations are increased. The mitochondrial ATP/ADP ratio increases by factor of <2 between thed-glucose threshold for bursting and continuous spiking. According to our simulations, relatively small changes in mitochondrial membrane potential (∼1 mV) caused by uptake of Ca2+ are sufficient to alter the cytoplasmic ATP/ADP ratio and influence ATP-sensitive K+ channels in the plasma membrane. In the simulations, these cyclic changes in the mitochondrial membrane potential are due to synchronization of futile cycle of Ca2+ from the cytoplasm through mitochondria via Ca2+ uniporters and Na+/Ca2+exchange. Our simulations predict steady mitochondrial Ca2+concentrations on the order of 0.1 μM at low glucose concentrations that become oscillatory with an amplitude on the order of 0.5 μM during bursting. Abrupt increases in mitochondrial Ca2+concentration >5 μM may occur during continuous electrical activity.

Exogenous L-carnitine a meliorated burn-induced cellular and mitochondrial injuries of hepatocytes via recovering CPT1 activity

2021 ◽  
Author(s):  
Pengtao Li ◽  
Zhengguo Xia ◽  
Weichang Kong ◽  
Qiong Wang ◽  
Ziyue Zhao ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Membrane Potential ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Membrane Potential ◽  
Differentially Expressed Genes ◽  
Liver Tissue ◽  
Mitochondrial Membrane ◽  
Cellular Fatty Acid ◽  
Burn Patients ◽  
Severe Burn

Abstract Background : Impaired liver fatty acid metabolism and persistent mitochondrial dysfunction are common phenomena and associated with liver failure. Decreased serum L-carnitine, a vitamin involved in fatty-acid and energy metabolisms, has been reported in severe burn patients. The current research aimed to study the effects and mechanism of L-carnitine on mitochondrial damage and other hepatocytic injuries. Methods : Serum carnitine and indicators for hepatocytic injuries including AST, ALT, LDH, TG and OCT in severe burn patients and healthy controls were analyzed. The burn model in rats was established by skin scalding, and the carnitine was administered to the rats. The indicators mentioned above in the serum, and oil red staining, TUNEL staining and TEM observation, mitochondrial membrane potential, and CPT1 activity as well as CPT1 expression of the liver tissue were examined. HepG2 cells, treated with the CPT1 inhibitor etomoxir, were supplied with/without carnitine for 24h. The indicators mentioned above were examined, and apoptotic cells were analyzed by flow cytometry. Transcriptom high throughput sequencing of the rat liver tissues was performed, and differentially expressed genes Fabp4, Acacb, Acsm5 and Pnpla3 were further determined by RT-qPCR. Results : Significantly decreased carnitine and increased AST, ALT, LDH and OCT in the serum were detected in the severe burn patients and the scalded rats. Accumulation of TG, obvious mitochondrial shrinking, altered mitochondrial membrane potential, decreased ketogenesis and declined CPT1 activity were found in the liver tissue of the scalded rats. Administration of carnitine recovered CPT1 activity and improved all the parameters for cellular, fatty acid metabolic and mitochondrial injuries. Inhibition of CPT1 activity with etomoxir in vitro induced similar hepatocytic injuries found in the burn patients and the scalded rats, and supplementation of carnitine restored CPT1 activity and ameliorated these injuries. Differentially expressed genes Fabp4, Acacb, Acsm5 and Pnpla3 in the liver tissue and in the etomoxir-treated hepatocytes were also restored by exogenous carnitine. Conclusion : Exogenous carnitine exerts its protective effect on severe burn-induced cellular, fatty-acid metabolic and mitochondrial dysfunction of the hepatocytes via restore of CPT1 activity.

NAD+ deficiency and mitochondrial dysfunction in granulosa cells of women with polycystic ovary syndrome‡

2021 ◽  
Author(s):  
Yujiao Wang ◽  
Qingling Yang ◽  
Huan Wang ◽  
Jing Zhu ◽  
Luping Cong ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Polycystic Ovary Syndrome ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Membrane Potential ◽  
Granulosa Cells ◽  
Mitochondrial Membrane ◽  
Polycystic Ovary ◽  
Tumor Cell Line ◽  
Ovary Syndrome ◽  
Atp Generation

Abstract Polycystic ovary syndrome (PCOS) is a prevalent heterogeneous endocrine disorder characterized by ovulation dysfunction, androgen excess, ovarian polycystic changes, insulin resistance, and infertility. Although underlying mechanisms for PCOS are still unknown, inflammation and mitochondrial dysfunction in granulosa cells (GCs) of PCOS patients have been reported. Here, we found that Nicotinamide Adenine Dinucleotide (NAD+) levels in GCs of PCOS patients was significantly decreased when compared with controls. Also, we found that higher expression of inflammation factors, increased reactive oxygen species (ROS) accumulation, lower adenosine triphosphate (ATP) generation, and decreased mitochondrial membrane potential, as well as abnormal mitochondrial dynamics in GCs of PCOS patients. In addition, the NAD+ levels were decreased after activation of inflammation in human granulosa-like tumor cell line (KGN) treated by Lipopolysaccharide (LPS). However, supplementation of nicotinamide riboside (NR), a NAD+ precursor, could largely restore the NAD+ content, reduce ROS levels and improve mitochondrial function demonstrated by increased mitochondrial membrane potential and ATP generation in LPS-treated KGN cells. Our data suggested that inflammation decreased NAD+ levels in GCs of PCOS patients, while supplementation of NR could restore NAD+ levels and alleviated mitochondrial dysfunction in GCs of PCOS patients.

scholarly journals Mitochondrial dysfunction in antiphospholipid syndrome: implications in the pathogenesis of the disease and effects of coenzyme Q10 treatment

Blood ◽  
2012 ◽  
Vol 119 (24) ◽  
pp. 5859-5870 ◽  
Author(s):  
Carlos Perez-Sanchez ◽  
Patricia Ruiz-Limon ◽  
Maria Angeles Aguirre ◽  
Maria Laura Bertolaccini ◽  
Munther A. Khamashta ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Membrane Potential ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Membrane Potential ◽  
Antiphospholipid Syndrome ◽  
Coenzyme Q10 ◽  
Mitochondrial Membrane ◽  
Antiphospholipid Antibody ◽  
Antibody Treatment

Abstract The exact mechanisms underlying the role of oxidative stress in the pathogenesis and the prothrombotic or proinflammatory status of antiphospholipid syndrome (APS) remain unknown. Here, we investigate the role of oxidative stress and mitochondrial dysfunction in the proatherothrombotic status of APS patients induced by IgG-antiphospholipid antibodies and the beneficial effects of supplementing cells with coenzyme Q10 (CoQ10). A significant increase in relevant prothrombotic and inflammatory parameters in 43 APS patients was found compared with 38 healthy donors. Increased peroxide production, nuclear abundance of Nrf2, antioxidant enzymatic activity, decreased intracellular glutathione, and altered mitochondrial membrane potential were found in monocytes and neutrophils from APS patients. Accelerated atherosclerosis in APS patients was found associated with their inflammatory or oxidative status. CoQ10 preincubation of healthy monocytes before IgG-antiphospholipid antibody treatment decreased oxidative stress, the percentage of cells with altered mitochondrial membrane potential, and the induced expression of tissue factor, VEGF, and Flt1. In addition, CoQ10 significantly improved the ultrastructural preservation of mitochondria and prevented IgG-APS–induced fission mediated by Drp-1 and Fis-1 proteins. In conclusion, the oxidative perturbation in APS patient leukocytes, which is directly related to an inflammatory and pro-atherothrombotic status, relies on alterations in mitochondrial dynamics and metabolism that may be prevented, reverted, or both by treatment with CoQ10.

scholarly journals Structurally optimised BODIPY derivatives for imaging of mitochondrial dysfunction in cancer and heart cells

2016 ◽  
Vol 52 (44) ◽  
pp. 7114-7117 ◽  
Author(s):  
Shubhanchi Nigam ◽  
Benjamin P. Burke ◽  
Laura H. Davies ◽  
Juozas Domarkas ◽  
Jennifer F. Wallis ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Dysfunction ◽  
Optical Imaging ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Imaging Agents ◽  
Heart Cells

BODIPY based optical imaging agents with mitochondrial membrane potential dependent uptake are described.

scholarly journals Development of a No-Wash Assay for Mitochondrial Membrane Potential Using the Styryl Dye DASPEI

2010 ◽  
Vol 15 (9) ◽  
pp. 1071-1081 ◽  
Author(s):  
Kristian H. R. Jensen ◽  
Jens C. Rekling
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Membrane Potential ◽  
Cho Cells ◽  
Mitochondrial Membrane ◽  
Large Scale ◽  
Chinese Hamster ◽  
Amyloid Β ◽  
Drug Target Discovery ◽  
Cellular Models

Mitochondrial dysfunction is a hallmark of several diseases and may also result from drugs with unwanted side effects on mitochondrial biochemistry. The mitochondrial membrane potential is a good indicator of mitochondrial function. Here, the authors have developed a no-wash mitochondrial membrane potential assay using 2-(4-(dimethylamino)styryl)-N-ethylpyridinium iodide (DASPEI), a rarely used mitochondrial potentiometric probe, in a 96-well format using a fluorescent plate reader. The assay was validated using 2 protonophores (CCCP, DNP), which are known uncouplers, and the neuroleptic thioridazine, which is a suspected mitochondrial toxicant. CCCP and DNP have short-term depolarizing effects, and thioridazine has long-term hyperpolarizing effects on the mitochondrial membrane potential of Chinese hamster ovary (CHO) cells. The assay also detected changes of the mitochondrial membrane potential in CHO cells exposed to cobalt (mimicking hypoxia) and in PC12 cells exposed to amyloid β, demonstrating that the assay can be used in cellular models of hypoxia and Alzheimer’s disease. The assay needs no washing steps, has a Z′ value >0.5, can be used on standard fluorometers, has good post liquid-handling stability, and thus is suitable for large-scale screening efforts. In summary, the DASPEI assay is simple and rapid and may be of use in toxicological testing, drug target discovery, and mechanistic models of diseases involving mitochondrial dysfunction.

scholarly journals Exposure to Plasma From Non-alcoholic Fatty Liver Disease Patients Affects Hepatocyte Viability, Generates Mitochondrial Dysfunction, and Modulates Pathways Involved in Fat Accumulation and Inflammation

2021 ◽  
Vol 8 ◽  
Author(s):  
Elena Grossini ◽  
Divya Praveen Garhwal ◽  
Giuseppe Calamita ◽  
Raffaele Romito ◽  
Cristina Rigamonti ◽  
...  
Keyword(s):  
Liver Disease ◽  
Membrane Potential ◽  
Fatty Liver ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Membrane Potential ◽  
Nlrp3 Inflammasome ◽  
Fatty Liver Disease ◽  
Mitochondrial Membrane ◽  
Alcoholic Fatty Liver ◽  
Alcoholic Fatty Liver Disease

Changes of lipidic storage, oxidative stress and mitochondrial dysfunction may be involved in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Although the knowledge of intracellular pathways has vastly expanded in recent years, the role and mechanisms of circulating triggering factor(s) are debated. Thus, we tested the hypothesis that factors circulating in the blood of NAFLD patients may influence processes underlying the disease. Huh7.5 cells/primary human hepatocytes were exposed to plasma from 12 NAFLD patients and 12 healthy subjects and specific assays were performed to examine viability, H2O2 and mitochondrial reactive oxygen species (ROS) release, mitochondrial membrane potential and triglycerides content. The involvement of NLRP3 inflammasome and of signaling related to peroxisome-proliferator-activating-ligand-receptor-γ (PPARγ), sterol-regulatory-element-binding-protein-1c (SREBP-1c), nuclear-factor-kappa-light-chain-enhancer of activated B cells (NF-kB), and NADPH oxidase 2 (NOX2) was evaluated by repeating the experiments in the presence of NLRP3 inflammasome blocker, MCC950, and through Western blot. The results obtained shown that plasma of NAFLD patients was able to reduce cell viability and mitochondrial membrane potential by about 48 and 24% (p &lt; 0.05), and to increase H2O2, mitochondrial ROS, and triglycerides content by about 42, 19, and 16% (p &lt; 0.05), respectively. An increased expression of SREBP-1c, PPARγ, NF-kB and NOX2 of about 51, 121, 63, and 46%, respectively, was observed (p &lt; 0.05), as well. Those effects were reduced by the use of MCC950. Thus, in hepatocytes, exposure to plasma from NAFLD patients induces a NAFLD-like phenotype by interference with NLRP3-inflammasome pathways and the activation of intracellular signaling related to SREBP-1c, PPARγ, NF-kB and NOX2.

scholarly journals Egr2 upregulation induced mitochondrial iron overload implicating in sevoflurane-induced cognitive deficits in developing mice

2020 ◽  
Author(s):  
Piao Zhang ◽  
Yeru Chen ◽  
Shuxia Zhang ◽  
Man Fang ◽  
Xianyi Lin ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Cognitive Function ◽  
Mitochondrial Dysfunction ◽  
Prussian Blue ◽  
Mitochondrial Membrane Potential ◽  
Cognitive Deficits ◽  
Mitochondrial Membrane ◽  
Bioinformatics Analysis ◽  
Blue Staining ◽  
Behavioral Tests

Abstract Background Sevoflurane inhalation initiated cognitive deficits implicated in mitochondrial dysfunction and synaptogenesis impairment. Bioinformatics analysis indicated that Egr2 may play a crucial role in maintaining cognitive function. Therefore, we attempted to clarify the potential mechanism regarding Egr2 expression and cognitive deficits induced by sevoflurane administration.Methods Animals received sevoflurane anesthesia, and the behavioral tests including Morris water maze, novel object recognition test and trace fear conditioning were performed. Then, the immunofluorescent staining was employed to detect the effect of sevoflurane inhalation in hippocampal neurons. Meanwhile, bioinformatics analysis was implemented, and the level of lipid peroxidation, mitochondrial membrane potential, morphology and membrane permeability, and cytoplasm calcium levels were investigated after Egr2 interference by using JC-1 probe, MitoTracker staining, Mitochondrial permeability transition pore (mPTP) assay, and Fluo calcium indicators, respectively. Additionally, Prussian blue staining was used to evaluate the iron content.Results The behavioral tests indicated that the cognitive function was significantly attenuated after sevoflurane administration. The Golgi-Cox staining displayed that the dendritic length, density and nodes were significantly reduced following sevoflurane inhalation. The bioinformatics analysis showed that sevoflurane administration results in the Egr2 expression upregulation. Additionally, the results suggested that sevoflurane administration elevated the cytoplasm calcium levels, reduced the mitochondrial membrane potential and triggered the opening of mPTP. Prussian blue staining showed that the iron deposition was apparently increased. However, Egr2 level downregulation partly reversed these above changes. Moreover, the behavioral performance was effectively improved after deferiprone (DFP) administration.Conclusion These findings demonstrated that sevoflurane administration elicited mitochondrial dysfunction and iron dyshomeostasis, and eventually resulted in cognitive impairments, whereas suppressing Egr2 expression partly improved this pathological process.

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