scholarly journals Dietary Tocotrienol/γ-Cyclodextrin Complex Increases Mitochondrial Membrane Potential and ATP Concentrations in the Brains of Aged Mice

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Anke Schloesser ◽  
Tuba Esatbeyoglu ◽  
Stefanie Piegholdt ◽  
Janina Dose ◽  
Naoko Ikuta ◽  
...  

Brain aging is accompanied by a decrease in mitochondrial function. In vitro studies suggest that tocotrienols, includingγ- andδ-tocotrienol (T3), may exhibit neuroprotective properties. However, little is known about the effect of dietary T3 on mitochondrial function in vivo. In this study, we monitored the effect of a dietary T3/γ-cyclodextrin complex (T3CD) on mitochondrial membrane potential and ATP levels in the brain of 21-month-old mice. Mice were fed either a control diet or a diet enriched with T3CD providing 100 mg T3 per kg diet for 6 months. Dietary T3CD significantly increased mitochondrial membrane potential and ATP levels compared to those of controls. The increase in MMP and ATP due to dietary T3CD was accompanied by an increase in the protein levels of the mitochondrial transcription factor A (TFAM). Furthermore, dietary T3CD slightly increased the mRNA levels of superoxide dismutase,γ-glutamyl cysteinyl synthetase, and heme oxygenase 1 in the brain. Overall, the present data suggest that T3CD increases TFAM, mitochondrial membrane potential, and ATP synthesis in the brains of aged mice.

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Pamela Harding ◽  
Timothy D Bryson ◽  
Indrani Datta ◽  
Yun Wang ◽  
Albert Levin

Hypertension is a leading cause of heart failure and both conditions are characterized by increased prostaglandin E2 (PGE2) which signals through 4 receptor subtypes (EP1-EP4) to elicit diverse physiologic effects. We previously reported that cardiomyocyte-specific deletion of the EP4 receptor results in a phenotype of dilated cardiomyopathy in male mice that is characterized by reduced ejection fraction. Subsequent gene array on left ventricles from these mice, coupled with Ingenuity Pathway Analysis (IPA) demonstrated that genes differentiating WT mice and EP4 KO mice with low ejection fraction were significantly overrepresented in mitochondrial (p=2.51x10 -28 ) and oxidative phosphorylation (p=3.16 x10 -30 ) pathways. We therefore hypothesized that PGE2 could reduce mitochondrial function. To test this hypothesis, we used isolated mouse cardiomyocytes (AVM) from 16-18 week old male C57Bl/6 mice and treated them with 1 μM PGE2 for various times. Mitochondrial gene expression was examined using a RT-profiler kit for mitochondrial energy metabolism, complex I activity with a spectrophotometric assay, ATP levels with a bioluminescence assay and mitochondrial membrane potential using JC-1 staining. Treatment of AVM with PGE2 for 4 hrs reduced expression of multiple genes from mitochondrial pathways including sub units of mitochondrial NADH dehydrogenase ubiquinone flavoprotein (Nduf), a component of complex I. In accord with the mRNA data, Complex I activity was reduced by 50% (p < 0.05) by 4 hr treatment with PGE2, from 1.32 ± 0.36 to 0.66 ± 0.08 mOD/min. Cytochrome c oxidase subunit 8 (Cox8c) mRNA was also reduced from a control value of 1.00 to -1.75 ± 0.20 (p < 0.005) after PGE2 treatment. Immuno-fluorescence showed that JC-1 aggregates were reduced after 1 or 3 hr treatment with either 1 μM PGE2 or the EP3 agonist, sulprostone, suggesting reduced mitochondrial membrane potential. Subsequent experiments also showed that ATP levels were reduced 16% from 11.18 ± 0.71 nmol to 9.39 ± 0.83 nmol after treatment with sulprostone for only 1 hr. Taken together, these results suggest that increased PGE2 in hypertension may contribute to impaired mitochondrial function and provide yet another link between inflammation and cardiac dysfunction.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Carsten Esselun ◽  
Bastian Bruns ◽  
Stephanie Hagl ◽  
Rekha Grewal ◽  
Gunter P. Eckert

The Mediterranean plant Silybum marianum L., commonly known as milk thistle, has been used for centuries to treat liver disorders. The flavonolignan silibinin represents a natural antioxidant and the main bioactive ingredient of silymarin (silybin), a standard extract of its seeds. Mitochondrial dysfunction and the associated generation of reactive oxygen/nitrogen species (ROS/RNS) are involved in the development of chronic liver and age-related neurodegenerative diseases. Silibinin A (SIL A) is one of two diastereomers found in silymarin and was used to evaluate the effects of silymarin on mitochondrial parameters including mitochondrial membrane potential and ATP production with and without sodium nitroprusside- (SNP-) induced nitrosative stress, oxidative phosphorylation, and citrate synthase activity in HepG2 and PC12 cells. Both cell lines were influenced by SIL A, but at different concentrations. SIL A significantly weakened nitrosative stress in both cell lines. Low concentrations not only maintained protective properties but also increased basal mitochondrial membrane potential (MMP) and adenosine triphosphate (ATP) levels. However, these effects could not be associated with oxidative phosphorylation. On the other side, high concentrations of SIL A significantly decreased MMP and ATP levels. Although SIL A did not provide a general improvement of the mitochondrial function, our findings show that SIL A protects against SNP-induced nitrosative stress at the level of mitochondria making it potentially beneficial against neurological disorders.


Author(s):  
Carsten Esselun ◽  
Benjamin Dilberger ◽  
Carmina V. Silaidos ◽  
Elisabeth Koch ◽  
Nils Helge Schebb ◽  
...  

AbstractThis in vivo study aimed to test if a diet enriched with 6% walnuts alone or in combination with physical activity supports healthy ageing by changing the oxylipin profile in brain and liver, improving motor function, cognition, and cerebral mitochondrial function. Female NMRI mice were fed a 6% walnut diet starting at an age of 12 months for 24 weeks. One group was additionally maintained in an enriched environment, one group without intervention served as control. After three months, one additional control group of young mice (3 weeks old) was introduced. Motor and cognitive functions were measured using Open Field, Y-Maze, Rotarod and Passive Avoidance tests. Lipid metabolite profiles were determined using RP-LC-ESI(-)-MS/MS in brain and liver tissues of mice. Cerebral mitochondrial function was characterized by the determination of ATP levels, mitochondrial membrane potential and mitochondrial respiration. Expression of genes involved with mito- and neurogenesis, inflammation, and synaptic plasticity were determined using qRT-PCR. A 6% walnut-enriched diet alone improved spatial memory in a Y-Maze alternation test (p < 0.05) in mice. Additional physical enrichment enhanced the significance, although the overall benefit was virtually identical. Instead, physical enrichment improved motor performance in a Rotarod experiment (p* < 0.05) which was unaffected by walnuts alone. Bioactive oxylipins like hydroxy-polyunsaturated fatty acids (OH-PUFA) derived from linoleic acid (LA) were significantly increased in brain (p** < 0.01) and liver (p*** < 0.0001) compared to control mice, while OH-PUFA of α-linolenic acid (ALA) could only be detected in the brains of mice fed with walnuts. In the brain, walnuts combined with physical activity reduced arachidonic acid (ARA)-based oxylipin levels (p < 0.05). Effects of walnut lipids were not linked to mitochondrial function, as ATP production, mitochondrial membrane potential and mitochondrial respiration were unaffected. Furthermore, common markers for synaptic plasticity and neuronal growth, key genes in the regulation of cytoprotective response to oxidative stress and neuronal growth were unaffected. Taken together, walnuts change the oxylipin profile in liver and brain, which could have beneficial effects for healthy ageing, an effect that can be further enhanced with an active lifestyle. Further studies may focus on specific nutrient lipids that potentially provide preventive effects in the brain.


2019 ◽  
Vol 18 (4) ◽  
pp. 334-341 ◽  
Author(s):  
Kun Fu ◽  
Liqiang Chen ◽  
Lifeng Miao ◽  
Yan Guo ◽  
Wei Zhang ◽  
...  

Background/Objective: Grape seed proanthocyanidins (GSPs) are a group of polyphenolic bioflavonoids, which possess a variety of biological functions and pharmacological properties. We studied the neuroprotective effects of GSP against oxygen-glucose deprivation/reoxygenation (OGD/R) injury and the potential mechanisms in mouse neuroblastoma N2a cells. Methods: OGD/R was conducted in N2a cells. Cell viability was evaluated by CCK-8 and LDH release assay. Apoptosis was assessed by TUNEL staining and flow cytometry. Protein levels of cleaved caspase-3, Bax and Bcl-2 were detected by Western blotting. CHOP, GRP78 and caspase-12 mRNA levels were assessed by real-time PCR. JC-1 dying was used to detect mitochondrial membrane potential. ROS levels, activities of endogenous antioxidant enzymes and ATP production were examined to evaluate mitochondrial function. Results: GSP increased cell viability after OGD/R injury in a dose-dependent manner. Furthermore, GSP inhibited cell apoptosis, reduced the mRNA levels of CHOP, GRP78 and caspase-12 (ER stressassociated genes), restored mitochondrial membrane potential and ATP generation, improved activities of endogenous anti-oxidant ability (T-AOC, GXH-Px, and SOD), and decreased ROS level. Conclusion: Our findings suggest that GSP can protect N2a cells from OGD/R insult. The mechanism of anti-apoptotic effects of GSP may involve attenuating ER stress and mitochondrial dysfunction.


Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 153
Author(s):  
Nikita G. Nikiforov ◽  
Anastasia Ryabova ◽  
Marina V. Kubekina ◽  
Igor D. Romanishkin ◽  
Kirill A. Trofimov ◽  
...  

Atherosclerosis is associated with a chronic local inflammatory process in the arterial wall. Our previous studies have demonstrated the altered proinflammatory activity of circulating monocytes in patients with atherosclerosis. Moreover, atherosclerosis progression and monocyte proinflammatory activity were associated with mitochondrial DNA (mtDNA) mutations in circulating monocytes. The role of mitochondria in the immune system cells is currently well recognized. They can act as immunomodulators by releasing molecules associated with bacterial infection. We hypothesized that atherosclerosis can be associated with changes in the mitochondrial function of circulating monocytes. To test this hypothesis, we performed live staining of the mitochondria of CD14+ monocytes from healthy donors and atherosclerosis patients with MitoTracker Orange CMTMRos dye, which is sensitive to mitochondrial membrane potential. The intensity of such staining reflects mitochondrial functional activity. We found that parts of monocytes in the primary culture were characterized by low MitoTracker staining (MitoTracker-low monocytes). Such cells were morphologically similar to cells with normal staining and able to metabolize 5-aminolevulinic acid and accumulate the heme precursor protoporphyrin IX (PplX), indicative of partially preserved mitochondrial function. We assessed the proportion of MitoTracker-low monocytes in the primary culture for each study subject and compared the results with other parameters, such as monocyte ability to lipopolysaccharide (LPS)-induced proinflammatory activation and the intima-media thickness of carotid arteries. We found that the proportion of MitoTracker-low monocytes was associated with the presence of atherosclerotic plaques. An increased number of such monocytes in the primary culture was associated with a reduced proinflammatory activation ability of cells. The obtained results indicate the presence of circulating monocytes with mitochondrial dysfunction and the association of such cells with chronic inflammation and atherosclerosis development.


Author(s):  
Luukkonen Jukka ◽  
Höytö Anne ◽  
Sokka Miiko ◽  
Syväoja Juhani ◽  
Juutilainen Jukka ◽  
...  

AbstractIonizing radiation has been shown to cause induced genomic instability (IGI), which is defined as a persistently increased rate of genomic damage in the progeny of the exposed cells. In this study, IGI was investigated by exposing human SH-SY5Y neuroblastoma cells to hydroxyurea and zeocin, two chemicals mimicking different DNA-damaging effects of ionizing radiation. The aim was to explore whether IGI was associated with persistent mitochondrial dysfunction. Changes to mitochondrial function were assessed by analyzing mitochondrial superoxide production, mitochondrial membrane potential, and mitochondrial activity. The formation of micronuclei was used to determine immediate genetic damage and IGI. Measurements were performed either immediately, 8 days, or 15 days following exposure. Both hydroxyurea and zeocin increased mitochondrial superoxide production and affected mitochondrial activity immediately after exposure, and mitochondrial membrane potential was affected by zeocin, but no persistent changes in mitochondrial function were observed. IGI became manifested 15 days after exposure in hydroxyurea-exposed cells. In conclusion, immediate responses in mitochondrial function did not cause persistent dysfunction of mitochondria, and this dysfunction was not required for IGI in human neuroblastoma cells.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Martina Reutzel ◽  
Rekha Grewal ◽  
Carmina Silaidos ◽  
Jens Zotzel ◽  
Stefan Marx ◽  
...  

Aging represents a major risk factor for developing neurodegenerative diseases such as Alzheimer’s disease (AD). As components of the Mediterranean diet, olive polyphenols may play a crucial role in the prevention of AD. Since mitochondrial dysfunction acts as a final pathway in both brain aging and AD, respectively, the effects of a mixture of highly purified olive secoiridoids were tested on cognition and ATP levels in a commonly used mouse model for brain aging. Over 6 months, female NMRI mice (12 months of age) were fed with a blend containing highly purified olive secoiridoids (POS) including oleuropein, hydroxytyrosol and oleurosid standardized for 50 mg oleuropein/kg diet (equivalent to 13.75 mg POS/kg b.w.) or the study diet without POS as control. Mice aged 3 months served as young controls. Behavioral tests showed deficits in cognition in aged mice. Levels of ATP and mRNA levels of NADH-reductase, cytochrome-c-oxidase, and citrate synthase were significantly reduced in the brains of aged mice indicating mitochondrial dysfunction. Moreover, gene expression of Sirt1, CREB, Gap43, and GPx-1 was significantly reduced in the brain tissue of aged mice. POS-fed mice showed improved spatial working memory. Furthermore, POS restored brain ATP levels in aged mice which were significantly increased. Our results show that a diet rich in purified olive polyphenols has positive long-term effects on cognition and energy metabolism in the brain of aged mice.


2019 ◽  
Vol 21 (1) ◽  
pp. 220 ◽  
Author(s):  
Han-A Park ◽  
Nelli Mnatsakanyan ◽  
Katheryn Broman ◽  
Abigail U. Davis ◽  
Jordan May ◽  
...  

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.


2019 ◽  
Vol 25 (3) ◽  
pp. 240-250 ◽  
Author(s):  
Leila Hosseini ◽  
Manouchehr S. Vafaee ◽  
Reza Badalzadeh

Ischemic heart diseases are the major reasons for disability and mortality in elderly individuals. In this study, we tried to examine the combined effects of nicotinamide mononucleotide (NMN) preconditioning and melatonin postconditioning on cardioprotection and mitochondrial function in ischemia/reperfusion (I/R) injury of aged male rats. Sixty aged Wistar rats were randomly allocated to 5 groups, including sham, control, NMN-receiving, melatonin-receiving, and combined therapy (NMN+melatonin). Isolated hearts were mounted on Langendorff apparatus and then underwent 30-minue ligation of left anterior descending coronary artery to induce regional ischemic insult, followed by 60 minutes of reperfusion. Nicotinamide mononucleotide (100 mg/kg/d intraperitoneally) was administered for every other day for 28 days before I/R. Melatonin added to perfusion solution, 5 minutes prior to the reperfusion up to 15 minutes early reperfusion. Myocardial hemodynamic and infarct size (IS) were measured, and the left ventricles samples were obtained to evaluate cardiac mitochondrial function and oxidative stress markers. Melatonin postconditioning and NMN had significant cardioprotective effects in aged rats; they could improve hemodynamic parameters and reduce IS and lactate dehydrogenase release compared to those of control group. Moreover, pretreatment with NMN increased the cardioprotection by melatonin. All treatments reduced oxidative stress and mitochondrial reactive oxygen species (ROS) levels and improved mitochondrial membrane potential and restored NAD+/NADH ratio. The effects of combined therapy on reduction of mitochondrial ROS and oxidative status and improvement of mitochondrial membrane potential were greater than those of alone treatments. Combination of melatonin and NMN can be a promising strategy to attenuate myocardial I/R damages in aged hearts. Restoration of mitochondrial function may substantially contribute to this cardioprotection.


2019 ◽  
Vol 25 (11) ◽  
pp. 695-705 ◽  
Author(s):  
Usama AL-Zubaidi ◽  
Jun Liu ◽  
Ozgur Cinar ◽  
Rebecca L Robker ◽  
Deepak Adhikari ◽  
...  

Abstract Mitochondria are highly dynamic organelles and their distribution, structure and activity affect a wide range of cellular functions. Mitochondrial membrane potential (∆Ψm) is an indicator of mitochondrial activity and plays a major role in ATP production, redox balance, signaling and metabolism. Despite the absolute reliance of oocyte and early embryo development on mitochondrial function, there is little known about the spatial and temporal aspects of ΔΨm during oocyte maturation. The one exception is that previous findings using a ΔΨm indicator, JC-1, report that mitochondria in the cortex show a preferentially increased ΔΨm, relative to the rest of the cytoplasm. Using live-cell imaging and a new ratiometric approach for measuring ΔΨm in mouse oocytes, we find that ΔΨm increases through the time course of oocyte maturation and that mitochondria in the vicinity of the first meiotic spindle show an increase in ΔΨm, compared to other regions of the cytoplasm. We find no evidence for an elevated ΔΨm in the oocyte cortex. These findings suggest that mitochondrial activity is adaptive and responsive to the events of oocyte maturation at both a global and local level. In conclusion, we have provided a new approach to reliably measure ΔΨm that has shed new light onto the spatio-temporal regulation of mitochondrial function in oocytes and early embryos.


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