scholarly journals The Acute Extracellular Flux (XF) Assay to Assess Compound Effects on Mitochondrial Function

2014 ◽  
Vol 20 (3) ◽  
pp. 422-429 ◽  
Author(s):  
Ruolan Wang ◽  
Steven J. Novick ◽  
James B. Mangum ◽  
Kennedy Queen ◽  
David A. Ferrick ◽  
...  

Numerous investigations have linked mitochondrial dysfunction to adverse health outcomes and drug-induced toxicity. The pharmaceutical industry is challenged with identifying mitochondrial liabilities earlier in drug development and thereby reducing late-stage attrition. Consequently, there is a demand for reliable, higher-throughput screening methods for assessing the impact of drug candidates on mitochondrial function. The extracellular flux (XF) assay described here is a plate-based method in which galactose-conditioned HepG2 cells were acutely exposed to test compounds, then real-time changes in the oxygen consumption rate and extracellular acidification rate were simultaneously measured using a Seahorse Bioscience XF-96 analyzer. The acute XF assay was validated using marketed drugs known to modulate mitochondrial function, and data analysis was automated using a spline curve fitting model developed at GlaxoSmithKline. We demonstrate that the acute XF assay is a robust, sensitive screening platform for evaluating drug-induced effects on mitochondrial activity in whole cells.

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Bethany Muller ◽  
Niamh Lewis ◽  
Tope Adeniyi ◽  
Henry J. Leese ◽  
Daniel R. Brison ◽  
...  

AbstractMitochondria provide the major source of ATP for mammalian oocyte maturation and early embryo development. Oxygen Consumption Rate (OCR) is an established measure of mitochondrial function. OCR by mammalian oocytes and embryos has generally been restricted to overall uptake and detailed understanding of the components of OCR dedicated to specific molecular events remains lacking. Here, extracellular flux analysis (EFA) was applied to small groups of bovine, equine, mouse and human oocytes and bovine early embryos to measure OCR and its components. Using EFA, we report the changes in mitochondrial activity during the processes of oocyte maturation, fertilisation, and pre-implantation development to blastocyst stage in response to physiological demands in mammalian embryos. Crucially, we describe the real time partitioning of overall OCR to spare capacity, proton leak, non-mitochondrial and coupled respiration – showing that while activity changes over the course of development in response to physiological demand, the overall efficiency is unchanged. EFA is shown to be able to measure mitochondrial function in small groups of mammalian oocytes and embryos in a manner which is robust, rapid and easy to use. EFA is non-invasive and allows real-time determination of the impact of compounds on OCR, facilitating an assessment of the components of mitochondrial activity. This provides proof-of-concept for EFA as an accessible system with which to study mammalian oocyte and embryo metabolism.


2019 ◽  
Author(s):  
Bethany Muller ◽  
Niamh Lewis ◽  
Tope Adeniyi ◽  
Henry J Leese ◽  
Daniel Brison ◽  
...  

1.AbstractBackgroundMitochondria provide the major source of ATP for mammalian oocyte maturation and early embryo development. Oxygen Consumption Rate (OCR) is an established measure of mitochondrial function. OCR by mammalian oocytes and embryos has generally been restricted to overall uptake and detailed understanding of the components of OCR dedicated to specific molecular events remains lacking.ResultsHere, extracellular flux analysis (EFA) was applied to small groups of bovine, equine, mouse and human oocytes and bovine early embryos to measure OCR. Using EFA, we report the changes in mitochondrial activity during the processes of oocyte maturation, fertilization, and pre-implantation development to blastocyst stage in response to physiological demands in mammalian embryos. Crucially, we describe the real time partitioning of overall OCR to spare capacity, proton leak, non-mitochondrial and coupled respiration – showing that while there are alterations in activity over the course of development to respond to physiological demand, the overall efficiency is unchanged.ConclusionEFA is shown to be able to measure mitochondrial function in small groups of mammalian oocytes and embryos in a manner which is robust, rapid and easy to use. EFA is non-invasive and allows real-time determination of the impact of compounds on OCR, facilitating an assessment of the parameters of mitochondrial activity. This provides proof-of-concept for EFA as an accessible system with which to study oocyte and embryo metabolism.


Author(s):  
Amy L. Ball ◽  
Katarzyna M. Bloch ◽  
Lucille Rainbow ◽  
Xuan Liu ◽  
John Kenny ◽  
...  

AbstractMitochondrial DNA (mtDNA) is highly polymorphic and encodes 13 proteins which are critical to the production of ATP via oxidative phosphorylation. As mtDNA is maternally inherited and undergoes negligible recombination, acquired mutations have subdivided the human population into several discrete haplogroups. Mitochondrial haplogroup has been found to significantly alter mitochondrial function and impact susceptibility to adverse drug reactions. Despite these findings, there are currently limited models to assess the effect of mtDNA variation upon susceptibility to adverse drug reactions. Platelets offer a potential personalised model of this variation, as their anucleate nature offers a source of mtDNA without interference from the nuclear genome. This study, therefore, aimed to determine the effect of mtDNA variation upon mitochondrial function and drug-induced mitochondrial dysfunction in a platelet model. The mtDNA haplogroup of 383 healthy volunteers was determined using next-generation mtDNA sequencing (Illumina MiSeq). Subsequently, 30 of these volunteers from mitochondrial haplogroups H, J, T and U were recalled to donate fresh, whole blood from which platelets were isolated. Platelet mitochondrial function was tested at basal state and upon treatment with compounds associated with both mitochondrial dysfunction and adverse drug reactions, flutamide, 2-hydroxyflutamide and tolcapone (10–250 μM) using extracellular flux analysis. This study has demonstrated that freshly-isolated platelets are a practical, primary cell model, which is amenable to the study of drug-induced mitochondrial dysfunction. Specifically, platelets from donors of haplogroup J have been found to have increased susceptibility to the inhibition of complex I-driven respiration by 2-hydroxyflutamide. At a time when individual susceptibility to adverse drug reactions is not fully understood, this study provides evidence that inter-individual variation in mitochondrial genotype could be a factor in determining sensitivity to mitochondrial toxicants associated with costly adverse drug reactions.


2014 ◽  
Vol 21 (10) ◽  
pp. 1262-1270 ◽  
Author(s):  
Aiden Haghikia ◽  
Simon Faissner ◽  
Derek Pappas ◽  
Bartosz Pula ◽  
Denis A Akkad ◽  
...  

Background:Whereas cellular immune function depends on energy supply and mitochondrial function, little is known on the impact of immunotherapies on cellular energy metabolism.Objective:The objective of this paper is to assess the effects of interferon-beta (IFN-β) on mitochondrial function of CD4+T cells.Methods:Intracellular adenosine triphosphate (iATP) in phytohemagglutinin (PHA)-stimulated CD4+cells of multiple sclerosis (MS) patients treated with IFN-β and controls were analyzed in a luciferase-based assay. Mitochondrial-transmembrane potential (ΔΨm) in IFN-β-treated peripheral blood mononuclear cells (PBMCs) was investigated by flow cytometry. Expression of genes involved in mitochondrial oxidative phosphorylation (OXPHOS) in CD4+cells of IFN-β-treated individuals and correlations between genetic variants in the key metabolism regulator PGC-1α and IFN-β response in MS were analyzed.Results:IFN-β-treated MS patients exhibited a dose-dependent reduction of iATP levels in CD4+T cells compared to controls ( p < 0.001). Mitochondrial effects were reflected by depolarization of ΔΨm. Expression data revealed changes in the transcription of OXPHOS-genes. iATP levels in IFN-β-responders were reduced compared to non-responders ( p < 0.05), and the major T allele of the SNP rs7665116 of PGC-1α correlated with iATP-levels.Conclusion:Reduced iATP-synthesis ex vivo and differential expression of OXPHOS-genes in CD4+T cells point to unknown IFN-β effects on mitochondrial energy metabolism, adding to potential pleiotropic mechanisms of action.


2020 ◽  
Vol 21 (23) ◽  
pp. 9153
Author(s):  
Kerry C. Ryan ◽  
Zahra Ashkavand ◽  
Kenneth R. Norman

Calcium signaling is essential for neuronal function, and its dysregulation has been implicated across neurodegenerative diseases, including Alzheimer’s disease (AD). A close reciprocal relationship exists between calcium signaling and mitochondrial function. Growing evidence in a variety of AD models indicates that calcium dyshomeostasis drastically alters mitochondrial activity which, in turn, drives neurodegeneration. This review discusses the potential pathogenic mechanisms by which calcium impairs mitochondrial function in AD, focusing on the impact of calcium in endoplasmic reticulum (ER)–mitochondrial communication, mitochondrial transport, oxidative stress, and protein homeostasis. This review also summarizes recent data that highlight the need for exploring the mechanisms underlying calcium-mediated mitochondrial dysfunction while suggesting potential targets for modulating mitochondrial calcium levels to treat neurodegenerative diseases such as AD.


Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 319
Author(s):  
Andrea Torres ◽  
Lilia G. Noriega ◽  
Claudia Delgadillo-Puga ◽  
Armando R. Tovar ◽  
Arturo Navarro-Ocaña

Owing to their antioxidant properties, caffeoylquinic acid (CQA)-derivatives could potentially improve the impaired metabolism in hepatic cells, however, their effect on mitochondrial function has not been demonstrated yet. Here, we evaluated the impact of three CQA-derivatives extracted from purple sweet potato, namely 5-CQA, 3,4- and 4,5-diCQA, on mitochondrial activity in primary hepatocytes using an extracellular flux analyzer. Notably, an increase of maximal respiration and spare respiratory capacity were observed when 5-CQA and 3,4-diCQA were added to the system indicating the improved mitochondrial function. Moreover, 3,4-diCQA was shown to considerably increase glycolytic reserve which is a measure of cell capability to respond to an energy demand through glycolysis. Conversely, 4,5-diCQA did not modify mitochondrial activity but increased glycolysis at low concentration in primary hepatocytes. All compounds tested improved cellular capacity to oxidize fatty acids. Overall, our results demonstrated the potential of test CQA-derivatives to modify mitochondrial function in hepatic cells. It is especially relevant in case of dysfunctional mitochondria in hepatocytes linked to hepatic steatosis during obesity, diabetes, and metabolic syndrome.


Author(s):  
Sarah A. Luse

In the mid-nineteenth century Virchow revolutionized pathology by introduction of the concept of “cellular pathology”. Today, a century later, this term has increasing significance in health and disease. We now are in the beginning of a new era in pathology, one which might well be termed “organelle pathology” or “subcellular pathology”. The impact of lysosomal diseases on clinical medicine exemplifies this role of pathology of organelles in elucidation of disease today.Another aspect of cell organelles of prime importance is their pathologic alteration by drugs, toxins, hormones and malnutrition. The sensitivity of cell organelles to minute alterations in their environment offers an accurate evaluation of the site of action of drugs in the study of both function and toxicity. Examples of mitochondrial lesions include the effect of DDD on the adrenal cortex, riboflavin deficiency on liver cells, elevated blood ammonia on the neuron and some 8-aminoquinolines on myocardium.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 371.1-371
Author(s):  
A. Koltakova ◽  
A. Lila ◽  
L. P. Ananyeva ◽  
A. Fedenko

Background:Pts with cancer may have MD that can be caused by neoplastic/paraneoplastic disease, rheumatic diseases or be induced by anticancer drug treatment. There is no data about MD influence on the QoL of cancer patients. The EORTC QoL questionnaire (QLQ)-C30 is a valid questionnaire designed to assess different aspects (Global health (GH), Functional (FS) and symptoms (SS) scales) that define the QoL of cancer patients [1].Objectives:The objective of the study was to assess the impact of drug induced and other types of MD on the QoL of cancer patients that received anticancer drug treatment by using of EORTC QLQ-C30 v3.0.Methods:The sampling of 123 pts (M/F – 40/83; mean age 54.4±12.8) with breast (32,5%), gastrointestinal (17%), ovary (8%), lung (7%) and other cancer was observed by rheumatologist in the oncology outpatient clinic. All pts received anticancer drug treatment: chemotherapy (104 pts), target therapy (16 pts) checkpoint-inhibitors (14 pts), hormone therapy (13 pts) in different combinations. 102(82.9%) of 123pts had MD include arthritis (12 pts), synovitis (5 pts), arthralgia (66 pts), periarthritis (34 pts), osteodynia (13 pts). There were 58 pts (group 1; M/F – 14/44; mean age 52.5±12.2) with anticancer drug treatment induced MD and 44 pts (group 2; M/F – 16/27; mean age 57.6±13.5) with other type of MD include 26 pts with skeletal metastasis. The were 21 pts (group 3; M/F – 10/11; mean age 52.9±11.1) without MD. All pts fulfilled EORTC QLQ-C30 v3.0 (tab.1).Table 1.The median [Q1;Q3] of results of GH, SS and SS of EORTC QLQ-C30ScaleSubscaleGroup1Group2Group3GH58.3[50;58]58.3[41.7;83.3]50[50;66.7]FS*Physical functioning73.3[60;86.7]73.3[66.7;86.7]86.7[80;93]Role functioning66.7[66.7;100]83.3[50;100]100[83;100]Emotional functioning83.3[66.7;100]75[66.7;91.7]91.6[83.3;100]Social functioning83.3[66.7;100]83.3[50;100]100[83.3;100]SS*Pain33.3[0;50]16.7[0;33.3]0[0;16.7]*There are only the scores that had got a statistical difference between the groups.Kruskal-Wallis H and post-hoc (Dwass-Steel-Critchlow-Fligner (DSCF) pairwise comparisons) tests for data analysis were performed.Results:A Kruskal-Wallis H test has shown a statistically significant difference in physical (χ2(2)=7.54; p=0.023), role (χ2(2)=9.87; p=0.007), emotion (χ2(2)=7.69; p=0.021) functioning and pain (χ2(2)=8.44; p=0.015) scores between the different groups. A post-hoc test with DSCF pairwise comparisons of median has shown a statistically significant difference between 1 and 3 groups (W=3.904; p=0.016) for physical functioning, between 2 and 3 groups (W=3.35; p=0.004) for role functioning, between 2 and 3 groups (W=4.03; p=0.012) for emotional functioning, between 1 and 3 groups (W=-3.97; p=0.014) for pain scale.Conclusion:The study has shown that MD associated with anticancer drug treatment adversely affected the QoL of cancer patients received anticancer drug treatment by reducing a physical functioning and by increasing pain scores. Presence of other types of MD adversely affect the QoL by reducing emotional and role functioning.References:[1]Aaronson NK,et al.The European Organization for Research and Treatment of Cancer QLQ-C30: a quality-of-life instrument for use in international clinical trials in oncology. J Natl Cancer Inst.1993;85(5):365-376. doi:10.1093/jnci/85.5.365Disclosure of Interests:None declared


2021 ◽  
Vol 22 (9) ◽  
pp. 4753
Author(s):  
Elisa Piscianz ◽  
Alessandra Tesser ◽  
Erika Rimondi ◽  
Elisabetta Melloni ◽  
Claudio Celeghini ◽  
...  

Mitoquinone (MitoQ) is a mitochondrial reactive oxygen species scavenger that is characterized by high bioavailability. Prior studies have demonstrated its neuroprotective potential. Indeed, the release of reactive oxygen species due to damage to mitochondrial components plays a pivotal role in the pathogenesis of several neurodegenerative diseases. The present study aimed to examine the impact of the inflammation platform activation on the neuronal cell line (DAOY) treated with specific inflammatory stimuli and whether MitoQ addition can modulate these deregulations. DAOY cells were pre-treated with MitoQ and then stimulated by a blockade of the cholesterol pathway, also called mevalonate pathway, using a statin, mimicking cholesterol deregulation, a common parameter present in some neurodegenerative and autoinflammatory diseases. To verify the role played by MitoQ, we examined the expression of genes involved in the inflammation mechanism and the mitochondrial activity at different time points. In this experimental design, MitoQ showed a protective effect against the blockade of the mevalonate pathway in a short period (12 h) but did not persist for a long time (24 and 48 h). The results obtained highlight the anti-inflammatory properties of MitoQ and open the question about its application as an effective adjuvant for the treatment of the autoinflammatory disease characterized by a cholesterol deregulation pathway that involves mitochondrial homeostasis.


Author(s):  
Yue Wu ◽  
Jieqiang Zhu ◽  
Peter Fu ◽  
Weida Tong ◽  
Huixiao Hong ◽  
...  

An effective approach for assessing a drug’s potential to induce autoimmune diseases (ADs) is needed in drug development. Here, we aim to develop a workflow to examine the association between structural alerts and drugs-induced ADs to improve toxicological prescreening tools. Considering reactive metabolite (RM) formation as a well-documented mechanism for drug-induced ADs, we investigated whether the presence of certain RM-related structural alerts was predictive for the risk of drug-induced AD. We constructed a database containing 171 RM-related structural alerts, generated a dataset of 407 AD- and non-AD-associated drugs, and performed statistical analysis. The nitrogen-containing benzene substituent alerts were found to be significantly associated with the risk of drug-induced ADs (odds ratio = 2.95, p = 0.0036). Furthermore, we developed a machine-learning-based predictive model by using daily dose and nitrogen-containing benzene substituent alerts as the top inputs and achieved the predictive performance of area under curve (AUC) of 70%. Additionally, we confirmed the reactivity of the nitrogen-containing benzene substituent aniline and related metabolites using quantum chemistry analysis and explored the underlying mechanisms. These identified structural alerts could be helpful in identifying drug candidates that carry a potential risk of drug-induced ADs to improve their safety profiles.


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