Cookies help us deliver our services. By using our services, you agree to our use of cookies. More information

Search by property

From Bioblast

This page provides a simple browsing interface for finding entities described by a property and a named value. Other available search interfaces include the page property search, and the ask query builder.

Search by property

A list of all pages that have property "Has abstract" with value "'''Background''': Reactive oxygen species (ROS) are among the main deter". Since there have been only a few results, also nearby values are displayed.

Showing below up to 10 results starting with #1.

View (previous 20 | next 20) (20 | 50 | 100 | 250 | 500)


    

List of results

  • Wijers 2008 PLoS One  + ('''BACKGROUND:''' Mild cold exposure and o ā€¦ '''BACKGROUND:''' Mild cold exposure and overfeeding are known to elevate energy expenditure in mammals, including humans. This process is called adaptive thermogenesis. In small animals, adaptive thermogenesis is mainly caused by mitochondrial uncoupling in brown adipose tissue and regulated via the sympathetic nervous system. In humans, skeletal muscle is a candidate tissue, known to account for a large part of the epinephrine-induced increase in energy expenditure. However, mitochondrial uncoupling in skeletal muscle has not extensively been studied in relation to adaptive thermogenesis in humans. Therefore we hypothesized that cold-induced adaptive thermogenesis in humans is accompanied by an increase in mitochondrial uncoupling in skeletal muscle.</br></br>'''METHODOLOGY/PRINCIPAL FINDINGS:''' The metabolic response to mild cold exposure in 11 lean, male subjects was measured in a respiration chamber at baseline and mild cold exposure. Skeletal muscle mitochondrial uncoupling (state 4) was measured in muscle biopsies taken at the end of the respiration chamber stays. Mild cold exposure caused a significant increase in 24h energy expenditure of 2.8% (0.32 MJ/day, range of -0.21 to 1.66 MJ/day, ''p''<0.05). The individual increases in energy expenditure correlated to state 4 respiration (''p''<0.02, ''R''(2) = 0.50).</br></br>'''CONCLUSIONS/SIGNIFICANCE:''' This study for the first time shows that in humans, skeletal muscle has the intrinsic capacity for cold induced adaptive thermogenesis via mitochondrial uncoupling under physiological conditions. This opens possibilities for mitochondrial uncoupling as an alternative therapeutic target in the treatment of obesity. therapeutic target in the treatment of obesity.)
  • MiPNet27.05 Schroecken BEC tutorial-Living Communications pmP  + ('''BEC tutorial-Living Communications. Fro ā€¦ '''BEC tutorial-Living Communications. From Peter Mitchellā€™s protonmotive force to protonmotive pressure: elements of the science of bioenergetics. </br>Preceding the '''[[MiPNet27.04 IOC155 Schroecken AT |Oroboros O2k-Workshop on high-resolution respirometry]]'''. Schroecken, Austria; 2022.</br>[[File:Gnaiger 2020 BEC MitoPathways.jpg|left|100px|link=Gnaiger_2020_BEC_MitoPathways|Gnaiger 2020 BEC MitoPathways]]</br>The [[mitochondrial membrane potential]] is an element of the science of bioenergetics, linked to the control of respiratory flux and related mitochondrial functions. A [https://pubmed.ncbi.nlm.nih.gov/?term=mitochondrial+membrane+potential PubMed search] on ā€˜mitochondrial membrane potentialā€™ yields 40 000 results and 3452 for 2021 (search 2022-09-20), with a linear increase during the past 20 years. [[Gnaiger_2020_BEC_MitoPathways#Chapter_8._Protonmotive_pressure_and_respiratory_control |Chapter 8]] on ā€˜Protonmotive pressure and respiratory controlā€™ of [[Mitochondrial Pathways]] (Gnaiger 2020) introduces a novel perspective on Peter Mitchellā€™s protonmotive force, which incorporates the mitochondrial membrane potential. If you find the reading is tough, you are not alone. Join this BEC tutorial-Living Communications for a fundamental introduction into the relevant concepts of physical chemistry, which differ from [[Force#Thermodynamic_ignorance |misleading chapters in bioenergetics textbooks]]. A retreat with plenty of informal discussions and group interactions takes you on a journey to visit chemical potential differences versus potential gradients, Gibbs [[energy]] versus Gibbs [[force]], quantities of capacity versus intensity, protonmotive force and [[motive unit]]s, [[flow]]s and [[force]]s, and finally protonmotive [[pressure]]. This will introduce students (and teachers) to a new understanding of mitochondrial membrane potential and the protonmotive force, connecting the ideal gas equation, osmotic pressure, the [[Boltzmann constant]] and [[gas constant]] with [[Fick 1855 Pogg Ann |Fickā€™s]] and [[Einstein 1905 Ann Physik 549 |Einsteinā€™s diffusion equation]]. If theory gets dry and grey, join for a swim in lake Kƶrbersee, for a Walk&Talk in the colorful alpine environment of the Schrƶcken-Tannberg region, and a visit to the [https://www.alpmuseum.at/ Alpmuseum ufm Tannberg].s://www.alpmuseum.at/ Alpmuseum ufm Tannberg].)
  • MiPNet27.08 Innsbruck BEC tutorial-Living Communications pmF  + ('''BEC tutorial-Living Communications. Mit ā€¦ '''BEC tutorial-Living Communications. Mitochondrial membrane potential and Peter Mitchellā€™s protonmotive force: elements of the science of bioenergetics. </br>[[File:Gnaiger 2020 BEC MitoPathways.jpg|left|100px|link=Gnaiger_2020_BEC_MitoPathways|Gnaiger 2020 BEC MitoPathways]]</br>The [[mitochondrial membrane potential]] is an element of the science of bioenergetics, linked to the control of respiratory flux and related mitochondrial functions. A PubMed search on ā€˜mitochondrial membrane potentialā€™ yields nearly 40 000 results and 3442 for 2021 (search 2022-07-04), with a linear increase during the past 20 years. [[Gnaiger_2020_BEC_MitoPathways#Chapter_8._Protonmotive_pressure_and_respiratory_control |Chapter 8]] on ā€˜Protonmotive pressure and respiratory controlā€™ of [[Mitochondrial Pathways]] (Gnaiger 2020) introduces a novel perspective on Peter Mitchellā€™s protonmotive force, which incorporates the mitochondrial membrane potential. If you find the reading is tough, you are not alone. Join this BEC tutorial-Living Communications for an introduction into the relevant concepts of physical chemistry, which differ from [[Force#Thermodynamic_ignorance |misleading chapters in bioenergetics textbooks]] on potential gradients, Gibbs ''[[energy]]'', protonmotive [[flow]] and [[force]], and finally protonmotive [[pressure]]. This will introduce students (and teachers) to a new understanding of mitochondrial membrane potential and the protonmotive force, connecting the ideal gas equation, osmotic pressure, the [[Boltzmann constant]] and [[gas constant]] with [[Fick 1855 Pogg Ann |Fickā€™s]] and [[Einstein 1905 Ann Physik 549 |Einsteinā€™s diffusion equation]]. If theory gets tough, join for a [[MiPNet27.05 BEC tutorial-Living Communications pmF |follow-up retreat]].C tutorial-Living Communications pmF |follow-up retreat]].)
  • MiPNet27.06 Prague BEC tutorial-Living Communications pmF  + ('''BEC tutorial-Living Communications. Mit ā€¦ '''BEC tutorial-Living Communications. Mitochondrial membrane potential and Peter Mitchellā€™s protonmotive force: elements of the science of bioenergetics. </br>Preceding the [[EMC2022 Prague CZ |EMC 2022 49th European Muscle Conference]], Prague, Czech Republic.</br>[[File:Gnaiger 2020 BEC MitoPathways.jpg|left|100px|link=Gnaiger_2020_BEC_MitoPathways|Gnaiger 2020 BEC MitoPathways]]</br>The [[mitochondrial membrane potential]] is an element of the science of bioenergetics, linked to the control of respiratory flux and related mitochondrial functions. A [https://pubmed.ncbi.nlm.nih.gov/?term=mitochondrial+membrane+potential PubMed search] on ā€˜mitochondrial membrane potentialā€™ yields 40 000 results and 3452 for 2021 (search 2022-09-20), with a linear increase during the past 20 years. [[Gnaiger_2020_BEC_MitoPathways#Chapter_8._Protonmotive_pressure_and_respiratory_control |Chapter 8]] on ā€˜Protonmotive pressure and respiratory controlā€™ of [[Mitochondrial Pathways]] (Gnaiger 2020) introduces a novel perspective on Peter Mitchellā€™s protonmotive force, which incorporates the mitochondrial membrane potential. If you find the reading is tough, you are not alone. Join this BEC tutorial-Living Communications for an introduction into the relevant concepts of physical chemistry, which differ from [[Force#Thermodynamic_ignorance |misleading chapters in bioenergetics textbooks]] on potential gradients, Gibbs ''[[energy]]'', protonmotive [[flow]] and [[force]], and finally protonmotive [[pressure]]. This will introduce students (and teachers) to a new understanding of mitochondrial membrane potential and the protonmotive force, connecting the ideal gas equation, osmotic pressure, the [[Boltzmann constant]] and [[gas constant]] with [[Fick 1855 Pogg Ann |Fickā€™s]] and [[Einstein 1905 Ann Physik 549 |Einsteinā€™s diffusion equation]]. If theory gets tough, join for a [[MiPNet27.05 BEC tutorial-Living Communications pmF |follow-up retreat]].C tutorial-Living Communications pmF |follow-up retreat]].)
  • Gruno 2008 J Gastroenterol  + ('''Background ''' Mitochondrial dysfuncti ā€¦ '''Background ''' </br>Mitochondrial dysfunction is one of the most characteristic properties of the cancer cell. However, it is not known whether oxidative energy metabolism has already become altered in conditions of atrophic gastritis, a precancerous state of gastric disease. The purpose of our study was to comparatively characterize oxidative phosphorylation (OXPHOS) in the atrophic and nonatrophic gastric corpus mucosa.</br></br>'''Methods''' </br>Mucosal biopsies were taken from 12 patients with corpus dominant atrophic gastritis and from 12 patients with nonatrophic mucosa (controls). One part of the tissue samples was permeabilized with saponin for analysis of the function of the respiratory chain using high-resolution respirometry, and another part was used for histopathological examination. The serum level of pepsinogen I (S-PGI) was determined with a specific enzyme immunoassay (EIA).</br></br>'''Results''' </br>Compared to the control group, the maximal capacity of OXPHOS in the atrophy group was almost twofold lower, the respiratory chain complex I-dependent respiration, normalized to complex II-dependent respiration, was reduced, and respiratory control by ADP in the presence of succinate was increased in the atrophic corpus mucosa. In the whole cohort of the patients studied, serum S-PGI level correlated positively with complex I-dependent respiration or complex Idependent to complex II-dependent respiration ratio.</br></br>'''Conclusions''' </br>Corpus dominant atrophic gastritis is characterized by decreased respiratory capacity and relative deficiency of the respiratory complex I of mitochondria in the mucosa, the latter defect probably limiting mitochondrial ATP production and energetic support of the secretory function of the zymogenic mucosal cells.y function of the zymogenic mucosal cells.)
  • Krebiehl 2010 PLoS One  + ('''Background''' Mitochondrial dysfunction ā€¦ '''Background''' Mitochondrial dysfunction and degradation takes a central role in current paradigms of neurodegeneration in Parkinson's disease (PD). Loss of DJ-1 function is a rare cause of familial PD. Although a critical role of DJ-1 in oxidative stress response and mitochondrial function has been recognized, the effects on mitochondrial dynamics and downstream consequences remain to be determined.</br></br>'''Methodology/Principal Findings''' Using DJ-1 loss of function cellular models from knockout (KO) mice and human carriers of the E64D mutation in the DJ-1 gene we define a novel role of DJ-1 in the integrity of both cellular organelles, mitochondria and lysosomes. We show that loss of DJ-1 caused impaired mitochondrial respiration, increased intramitochondrial reactive oxygen species, reduced mitochondrial membrane potential and characteristic alterations of mitochondrial shape as shown by quantitative morphology. Importantly, ultrastructural imaging and subsequent detailed lysosomal activity analyses revealed reduced basal autophagic degradation and the accumulation of defective mitochondria in DJ-1 KO cells, that was linked with decreased levels of phospho-activated ERK2.</br></br>'''Conclusions/Significance''' We show that loss of DJ-1 leads to impaired autophagy and accumulation of dysfunctional mitochondria that under physiological conditions would be compensated via lysosomal clearance. Our study provides evidence for a critical role of DJ-1 in mitochondrial homeostasis by connecting basal autophagy and mitochondrial integrity in Parkinson's disease.hondrial integrity in Parkinson's disease.)
  • Ross-Hellauer 2017 F1000Res  + ('''Background''': "Open peer review" (OPR) ā€¦ '''Background''': "Open peer review" (OPR), despite being a major pillar of Open Science, has neither a standardized definition nor an agreed schema of its features and implementations. The literature reflects this, with numerous overlapping and contradictory definitions. While for some the term refers to peer review where the identities of both author and reviewer are disclosed to each other, for others it signifies systems where reviewer reports are published alongside articles. For others it signifies both of these conditions, and for yet others it describes systems where not only "invited experts" are able to comment. For still others, it includes a variety of combinations of these and other novel methods. '''Methods''': Recognising the absence of a consensus view on what open peer review is, this article undertakes a systematic review of definitions of "open peer review" or "open review", to create a corpus of 122 definitions. These definitions are systematically analysed to build a coherent typology of the various innovations in peer review signified by the term, and hence provide the precise technical definition currently lacking. '''Results''': This quantifiable data yields rich information on the range and extent of differing definitions over time and by broad subject area. Quantifying definitions in this way allows us to accurately portray exactly how ambiguously the phrase "open peer review" has been used thus far, for the literature offers 22 distinct configurations of seven traits, effectively meaning that there are 22 different definitions of OPR in the literature reviewed. '''Conclusions''': I propose a pragmatic definition of open peer review as an umbrella term for a number of overlapping ways that peer review models can be adapted in line with the aims of Open Science, including making reviewer and author identities open, publishing review reports and enabling greater participation in the peer review process. participation in the peer review process.)
  • Ahn 2010 Biochim Biophys Acta  + ('''Background''': Atherosclerosis is one o ā€¦ '''Background''': Atherosclerosis is one of the major complications of diabetes, which may result from insulin resistance via mitochondrial dysfunction. Although a strong association between insulin resistance and cardiovascular disease has been suggested, it is not clear yet whether stress-inducing factors damage mitochondria and insulin signaling pathway in cardiovascular tissues.</br></br>'''Methods''': We investigated whether stress-induced mitochondrial dysfunction might alter the insulin/Akt signaling pathway in A10 rat vascular smooth muscle cells (VSMC).</br></br>'''Results''': The treatment of oxidized low density lipoprotein (oxLDL) decreased ATP contents, mitochondrial respiration activity, mRNA expressions of OXPHOS subunits and IRS-1/2 and insulin-mediated phosphorylations of Akt and AMP-activated protein kinase (AMPK). Similarly, dideoxycytidine (ddC), the mtDNA replication inhibitor, or rotenone, OXPHOS complex I inhibitor, inhibited the insulin-mediated pAkt while increased pAMPK regardless of insulin. Reciprocally, an inhibitor of Akt, triciribine (TCN), decreased cellular ATP contents. Overexpression of Akt dominant positive reversed the oxLDL- or ddC-mediated ATP decrease but AMPK activator did not. Akt activation also normalized the aberrant VSMC migration induced by ddC.</br></br>'''Conclusions''': Defective insulin signaling and mitochondrial function may collectively contribute to developing cardiovascular disease.</br></br>'''General significance''': Akt may be a possible therapeutic target for treating insulin resistance-associated atherosclerosis.lin resistance-associated atherosclerosis.)
  • Trimmer 2009 Mol Neurodegener  + ('''Background''': It has been hypothesized ā€¦ '''Background''': It has been hypothesized that reduced axonal transport contributes to the degeneration of neuronal processes in Parkinson's disease (PD). Mitochondria supply the adenosine triphosphate (ATP) needed to support axonal transport and contribute to many other cellular functions essential for the survival of neuronal cells. Furthermore, mitochondria in PD tissues are metabolically and functionally compromised. To address this hypothesis, we measured the velocity of mitochondrial movement in human transmitochondrial cybrid "cytoplasmic hybrid" neuronal cells bearing mitochondrial DNA from patients with sporadic PD and disease-free age-matched volunteer controls (CNT). The absorption of low level, near-infrared laser light by components of the mitochondrial electron transport chain (mtETC) enhances</br>mitochondrial metabolism, stimulates oxidative phosphorylation and improves redox capacity. PD and CNT cybrid neuronal cells were exposed to near-infrared laser light to determine if the velocity of mitochondrial movement can be restored by low level light therapy (LLLT). Axonal transport of labeled mitochondria was documented by time lapse microscopy in dopaminergic PD and CNT cybrid neuronal cells before and after illumination with an 810 nm diode laser (50 mW/cm<sup>2</sup>) for 40 s. Oxygen utilization and assembly of mtETS complexes were also determined.</br></br>'''Results''': The velocity of mitochondrial movement in PD cybrid neuronal cells (0.175 +/- 0.005 SEM) was significantly reduced (p < 0.02) compared to mitochondrial movement in disease free CNT cybrid neuronal cells (0.232 +/- 0.017 SEM). For two hours after LLLT, the average velocity of mitochondrial movement in PD cybrid neurites was significantly (p < 0.003) increased (to 0.224 +/- 0.02 SEM) and restored to levels comparable to CNT. Mitochondrial movement in CNT cybrid neurites was unaltered by LLLT (0.232 +/- 0.017 SEM). Assembly of complexes in the mtETC was reduced and oxygen utilization was altered in PD cybrid neuronal cells. PD cybrid neuronal cell lines with the most dysfunctional mtETC assembly and oxygen utilization profiles were least responsive to LLLT.</br></br>'''Conclusion''': The results from this study support our proposal that axonal transport is reduced in sporadic PD and that a single, brief treatment with near-infrared light can restore axonal transport to control levels. These results are the first demonstration that LLLT can increase axonal transport in model human dopaminergic neuronal cells and they suggest that LLLT could be developed as a novel treatment</br>to improve neuronal function in patients with PD. treatment to improve neuronal function in patients with PD.)
  • Droese 2009 Biochim Biophys Acta  + ('''Background''': Reactive oxygen species ā€¦ '''Background''': Reactive oxygen species (ROS) are among the main determinants of cellular damage during ischemia and reperfusion. There is also ample evidence that mitochondrial ROS production is involved in signaling during ischemic and pharmacological preconditioning. In a previous study we analyzed the mitochondrial effects of the efficient preconditioning drug diazoxide and found that it increased the mitochondrial oxidation of the ROS-sensitive fluorescent dye 2ā€²,7ā€²-dichlorodihydrofluorescein (H<sub>2</sub>DCF) but had no direct impact on the H<sub>2</sub>O<sub>2</sub> production of submitochondrial particles (SMP) or intact rat heart mitochondria (RHM).</br></br>'''Methods''': H<sub>2</sub>O<sub>2</sub> generation of bovine SMP and tightly coupled RHM was monitored under different conditions using the amplex red/horseradish peroxidase assay in response to diazoxide and a number of inhibitors.</br></br>'''Results''': We show that diazoxide reduces ROS production by mitochondrial Complex I under conditions of reverse electron transfer in tightly coupled RHM, but stimulates mitochondrial ROS production at the Qo site of Complex III under conditions of oxidant-induced reduction; this stimulation is greatly enhanced by uncoupling. These opposing effects can both be explained by inhibition of Complex II by diazoxide. 5-Hydroxydecanoate had no effect, and the results were essentially identical in the presence of Na<sup>+</sup> or K<sup>+</sup> excluding a role for putative mitochondrial KATP-channels.</br></br>'''General significance''': A straightforward rationale is presented to mechanistically explain the ambivalent effects of diazoxide reported in the literature. Depending on the metabolic state and the membrane potential of mitochondria, diazoxide-mediated inhibition of Complex II promotes transient generation of signaling ROS at Complex III (during preconditioning) or attenuates the production of deleterious ROS at Complex I (during ischemia and reperfusion).x III (during preconditioning) or attenuates the production of deleterious ROS at Complex I (during ischemia and reperfusion).)
 ('''Background''': Reactive oxygen species (ROS) are among the main deter)
  • Sokolova 2009 BMC Cell Biol  + ('''Background''': Restriction of intracell ā€¦ '''Background''': Restriction of intracellular diffusion of adenine nucleotides has been studied intensively on adult rat cardiomyocytes. However, their cause and role ''in vivo'' is still uncertain. Intracellular membrane structures have been suggested to play a role. We therefore chose to study cardiomyocytes from rainbow trout (''Oncorhynchus mykiss''), which are thinner and have fewer intracellular membrane structures than adult rat cardiomyocytes. Previous studies suggest that trout permeabilized cardiac fibers also have diffusion restrictions. However, results from fibers may be affected by incomplete separation of the cells. This is avoided when studying permeabilized, isolated cardiomyocytes. The aim of this study was to verify the existence of diffusion restrictions in trout cardiomyocytes by comparing ADP-kinetics of mitochondrial respiration in permeabilized fibers, permeabilized cardiomyocytes and isolated mitochondria from rainbow trout heart. Experiments were performed at 10, 15 and 20Ā°C in the absence and presence of creatine.</br></br>'''Results''': Trout cardiomyocytes hypercontracted in the solutions used for mammalian cardiomyocytes. We developed a new solution in which they retained their shape and showed stable steady state respiration rates throughout an experiment. The apparent ADP-affinity of permeabilized cardiomyocytes was different from that of fibers. It was higher, independent of temperature and not increased by creatine. However, it was still about ten times lower than in isolated mitochondria.</br></br>'''Conclusions''': The differences between fibers and cardiomyocytes suggest that results from trout heart fibers were affected by incomplete separation of the cells. However, the lower ADP-affinity of cardiomyocytes compared to isolated mitochondria indicate that intracellular diffusion restrictions are still present in trout cardiomyocytes despite their lower density of intracellular membrane structures. The lack of a creatine effect indicates that trout heart lacks mitochondrial creatine kinase tightly coupled to respiration. This argues against diffusion restriction by the outer mitochondrial membrane. These results from rainbow trout cardiomyocytes resemble those from other low-performance hearts such as neonatal rat and rabbit hearts. Thus, it seems that metabolic regulation is related to cardiac performance, and it is likely that rainbow trout can be used as a model animal for further studies of the localization and role of diffusion restrictions in lowperformance hearts.ion restrictions in lowperformance hearts.)
  • Amoedo 2011 PLoS One  + ('''Background''': Tumor cells are characte ā€¦ '''Background''': Tumor cells are characterized by accelerated growth usually accompanied by up-regulated pathways that ultimately increase the rate of ATP production. These cells can suffer metabolic reprogramming, resulting in distinct bioenergetic phenotypes, generally enhancing glycolysis channeled to lactate production. In the present work we showed metabolic reprogramming by means of inhibitors of histone deacetylase (HDACis), sodium butyrate and trichostatin. This treatment was able to shift energy metabolism by activating mitochondrial systems such as the respiratory chain and oxidative phosphorylation that were largely repressed in the untreated controls.</br></br>'''Methodology/Principal Findings''': Various cellular and biochemical parameters were evaluated in lung cancer H460 cells treated with the histone deacetylase inhibitors (HDACis), sodium butyrate (NaB) and trichostatin A (TSA). NaB and TSA reduced glycolytic flux, assayed by lactate release by H460 cells in a concentration dependent manner. NaB inhibited the expression of glucose transporter type 1 (GLUT 1), but substantially increased mitochondria bound hexokinase (HK) activity. NaB induced increase in HK activity was associated to isoform HK I and was accompanied by 1.5 fold increase in HK I mRNA expression and cognate protein biosynthesis. Lactate dehydrogenase (LDH) and pyruvate kinase (PYK) activities were unchanged by HDACis suggesting that the increase in the HK activity was not coupled to glycolytic flux. High resolution respirometry of H460 cells revealed NaB-dependent increased rates of oxygen consumption coupled to ATP synthesis. Metabolomic analysis showed that</br>NaB altered the glycolytic metabolite profile of intact H460 cells. Concomitantly we detected an activation of the pentose phosphate pathway (PPP). The high O2 consumption in NaB-treated cells was shown to be unrelated to mitochondrial biogenesis since citrate synthase (CS) activity and the amount of mitochondrial DNA remained unchanged.</br></br>'''Conclusion''': NaB and TSA induced an increase in mitochondrial function and oxidative metabolism in H460 lung tumor cells concomitant with a less proliferative cellular phenotype.h a less proliferative cellular phenotype.)
  • Gomez 2008 Circulation  + ('''Background'''ā€”Opening of the mitochondr ā€¦ '''Background'''ā€”Opening of the mitochondrial permeability transition pore (mPTP) is a crucial event in lethal reperfusion injury. Phosphorylation (inhibition) of glycogen synthase kinase-3Ī² (GSK3Ī²) has been involved in cardioprotection. We investigated whether phosphorylated GSK3Ī² may protect the heart via the inhibition of mPTP opening during postconditioning.</br></br>'''Methods and Results'''ā€”Wild-type and transgenic GSK3Ī²-S9A mice (the cardiac GSK3Ī² activity of which cannot be inactivated) underwent 60 minutes of ischemia and 24 hours of reperfusion. At reperfusion, wild-type and GSK3Ī²-S9A mice received no intervention (control), postconditioning (3 cycles of 1 minute ischemia and 1 minute of reperfusion), the mPTP inhibitor cyclosporine A (CsA; 10 mg/kg IV), or the GSK3Ī² inhibitor SB216763 (SB21; 70 Āµg/kg IV). Infarct size was assessed by triphenyltetrazolium chloride staining. The resistance of the mPTP to opening after Ca<sup>2+</sup> loading was assessed by spectrofluorometry on mitochondria isolated from the area at risk. In wild-type mice, infarct size was significantly reduced by postconditioning, CsA, and SB21, averaging 39Ā±2%, 35Ā±5%, and 37Ā±4%, respectively, versus 58Ā±5% of the area at risk in control mice (P<0.05). In GSK3Ī²-S9A mice, only CsA, but not postconditioning or SB21, reduced infarct size. Postconditioning, CsA, and SB21 all improved the resistance of the mPTP in wild-type mice, but only CsA did so in GSK3Ī²-S9A mice.</br></br>'''Conclusion'''ā€”These results suggest that S9-phosphorylation of GSK3Ī² is required for postconditioning and likely acts by inhibiting the opening of the mitochondrial permeability transition pore.pening of the mitochondrial permeability transition pore.)
  • Leadsham 2010 BMC Cell Biol  + ('''Background:''' Appropriate control of m ā€¦ '''Background:''' Appropriate control of mitochondrial function, morphology and biogenesis are crucial determinants of the general health of eukaryotic cells. It is therefore imperative that we understand the mechanisms that coordinate</br>mitochondrial function with environmental signaling systems. The regulation of yeast mitochondrial function in response to nutritional change can be modulated by PKA activity. Unregulated PKA activity can lead to the production of mitochondria that are prone to the production of ROS, and an apoptotic form of cell death.</br></br>'''Results:''' We present evidence that mitochondria are sensitive to the level of cAMP/PKA signaling and can respond by modulating levels of respiratory activity or committing to self execution. The inappropriate activation of one of</br>the yeast PKA catalytic subunits, Tpk3p, is sufficient to commit cells to an apoptotic death through transcriptional changes that promote the production of dysfunctional, ROS producing mitochondria. Our data implies that cAMP/</br>PKA regulation of mitochondrial function that promotes apoptosis engages the function of multiple transcription factors, including HAP4, SOK2 and SCO1.</br></br>'''Conclusions:''' We propose that in yeast, as is the case in mammalian cells, mitochondrial function and biogenesis are controlled in response to environmental change by the concerted regulation of multiple transcription factors. The visualization of cAMP/TPK3 induced cell death within yeast colonies supports a model that PKA regulation plays a physiological role in coordinating respiratory function and cell death with nutritional status in budding yeast. with nutritional status in budding yeast.)
  • Kalbacova 2003 Cytometry  + ('''Background:''' Determination of mitocho ā€¦ '''Background:''' Determination of mitochondrial membrane potential ((m) is widely used to characterize cellular metabolism, viability, and apoptosis. Changes of Ī”ĪØm induced by inhibitors of oxidative phosphorylation characterize</br>respective contributions of mitochondria and glycolysis to adenosine triphosphate (ATP) synthesis.</br>'''Methods:''' Ī”ĪØm in BSC-40 and HeLa G cell lines was determined by flow cytometry and spectrofluorometry. Its changes induced by specific mitochondrial inhibitors were evaluated using 3,3 Ī”ĪØ-dihexyloxacarbocyanine iodide</br>(DiOC6(3)), tetramethylrhodamine ethyl ester, and Mito-Tracker Red. Mitochondrial function was further characterized by oxygen consumption.</br>'''Results:''' Inhibition of respiration by antimycin A or uncoupling</br>of mitochondria by FCCP decreased Ī”ĪØm in both cell lines. Inhibition of ATP production by oligomycin or atractyloside induced a moderate decrease of Ī”ĪØm</br>in HeLa G cells and an increase of Ī”ĪØm in BSC-40 cells. Statistically significant differences in Ī”ĪØm between the two cell lines were found with both flow cytometry and spectrofluorometry. Respirometry showed higher basal</br>and FCCP-stimulated respiration in BSC-40 cells.</br>'''Conclusion:''' Changes of Ī”ĪØm and oxygen consumption showed that BSC-40 cells are more sensitive than HeLa G cells to inhibitors of mitochondrial function, suggesting that BSC-40 cells are more dependent than HeLa G cells on</br>aerobic ATP production. Determination of Ī”ĪØm changes by flow cytometry exhibited greater sensitivity than the ones by spectrofluorometry.ivity than the ones by spectrofluorometry.)
  • Hecker 2014 JPEN  + ('''Background:''' Sepsis is a severe infla ā€¦ '''Background:''' Sepsis is a severe inflammatory disorder with a high mortality in intensive care units mostly due to multiorgan failure. Mitochondrial dysfunction is regarded as a key factor involved in the pathogenesis of septic disorders, leading to a decline in energy supply. The aim of the present study was to evaluate whether application of short-chain fatty acids (SCFAs) and medium-chain fatty acids (MCFAs) could improve mitochondrial function and thus might serve as a potential energy source under inflammatory conditions. </br></br>'''Materials and Methods:''' As an experimental approach, starved human endothelial cells and monocytes were incubated with hexanoic acid, heptanoic acid, octanoic acid, or glucose and subsequently subjected to high-resolution respirometry to assess mitochondrial function under baseline conditions. In a second set of experiments, cells were pretreated with tumor necrosis factor-Ī± to mimic inflammation and sepsis. Results: We demonstrated that addition of SCFAs and MCFAs increases mitochondrial respiratory capacity at baseline and inflammatory conditions in both cell types. None of the fatty acids induced changes in mitochondrial DNA content or the generation of proinflammatory cytokines, indicating a beneficial safety profile. </br></br>'''Conclusion:''' We deduce that SCFAs and MCFAs are suitable and safe sources of energy under inflammatory conditions with the capability to partly restore mitochondrial respiration. partly restore mitochondrial respiration.)
  • Basal respiration  + ('''Basal respiration''' is well defined in physiology. Terminology in mitochondrial physiology gains quality by reference to established concepts.)
  • Bioblast 2022  + ('''Bioblast 2022: Inaugural Conference of ''Bioenergetics Communications''''')
  • Wiethuechter MiP2010  + ('''Bioblast''' was launched as a glossary ā€¦ '''Bioblast''' was launched as a glossary and index for high-resolution respirometry (Oroboros Instruments: OroboPedia) and Mitochondrial Physiology (MitoPedia), to find topics quickly, as a dynamic tool for summarizing definitions of terms, symbols and abbreviations. However, itĀ“s potential benefits as an innovative, self-developing database make the '''Bioblast Wiki''' much more than a service by Oroboros.i''' much more than a service by Oroboros.)
  • Bioenergetics Vienna  + ('''Bioenergetics Vienna''', 1st Bioenergetics DE-CH-AT Meeting)