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Syed M, Skonberg C, Hansen SH. Mitochondrial toxicity of selective COX-2 inhibitors via inhibition of oxidative phosphorylation (ATP synthesis) in rat liver mitochondria. Toxicol In Vitro 2015; 32:26-40. [PMID: 26689325 DOI: 10.1016/j.tiv.2015.12.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 10/14/2015] [Accepted: 12/08/2015] [Indexed: 10/22/2022]
Abstract
Cyclooxygenase-2 (COX-2) inhibitors (coxibs) are non-steroidal anti-inflammatory drugs (NSAIDs) designed to selectively inhibit COX-2. However, drugs of this therapeutic class are associated with drug induced liver injury (DILI) and mitochondrial injury is likely to play a role. The effects of selective COX-2 inhibitors on inhibition of oxidative phosphorylation (ATP synthesis) in rat liver mitochondria were investigated. The order of potency of inhibition of ATP synthesis was: lumiracoxib (IC50: 6.48 ± 2.74 μM)>celecoxib (IC50: 14.92 ± 6.40 μM)>valdecoxib (IC50: 161.4 ± 28.6 μM)>rofecoxib (IC50: 238.4 ± 79.2 μM)>etoricoxib (IC50: 405.1 ± 116.3 μM). Mechanism based inhibition of ATP synthesis (Kinact 0.078 min(-1) and KI 21.46 μM and Kinact/KI ratio 0.0036 min(-1)μM(-1)) was shown by lumiracoxib and data suggest that the opening of the MPT pore may not be the mechanism of toxicity. A positive correlation (with r(2)=0.921) was observed between the potency of inhibition of ATP synthesis and the log P values. The in vitro metabolism of coxibs in rat liver mitochondria yielded for each drug substance a major single metabolite and identified a hydroxy metabolite with each of the coxibs and these metabolites did not alter the inhibition profile of ATP synthesis of the parent compound. The results suggest that coxibs themselves could be involved in the hepatotoxic action through inhibition of ATP synthesis.
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Affiliation(s)
- Muzeeb Syed
- Section of Analytical Biosciences, Department of Pharmacy, School of Pharmaceutical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| | - Christian Skonberg
- Discovery ADME Department, Diabetes Pharmacology and Bioanalysis, Novo Nordisk A/S, Måløv, Copenhagen, Denmark
| | - Steen Honoré Hansen
- Section of Analytical Biosciences, Department of Pharmacy, School of Pharmaceutical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Transcriptional profiling suggests that Nevirapine and Ritonavir cause drug induced liver injury through distinct mechanisms in primary human hepatocytes. Chem Biol Interact 2015; 255:31-44. [PMID: 26626330 DOI: 10.1016/j.cbi.2015.11.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 10/28/2015] [Accepted: 11/20/2015] [Indexed: 12/25/2022]
Abstract
Drug induced liver injury (DILI), a major cause of pre- and post-approval failure, is challenging to predict pre-clinically due to varied underlying direct and indirect mechanisms. Nevirapine, a non-nucleoside reverse transcriptase inhibitor (NNRTI) and Ritonavir, a protease inhibitor, are antiviral drugs that cause clinical DILI with different phenotypes via different mechanisms. Assessing DILI in vitro in hepatocyte cultures typically requires drug exposures significantly higher than clinical plasma Cmax concentrations, making clinical interpretations of mechanistic pathway changes challenging. We previously described a system that uses liver-derived hemodynamic blood flow and transport parameters to restore primary human hepatocyte biology, and drug responses at concentrations relevant to in vivo or clinical exposure levels. Using this system, primary hepatocytes from 5 human donors were exposed to concentrations approximating clinical therapeutic and supra-therapeutic levels of Nevirapine (11.3 and 175.0 μM) and Ritonavir (3.5 and 62.4 μM) for 48 h. Whole genome transcriptomics was performed by RNAseq along with functional assays for metabolic activity and function. We observed effects at both doses, but a greater number of genes were differentially expressed with higher probability at the toxic concentrations. At the toxic doses, both drugs showed direct cholestatic potential with Nevirapine increasing bile synthesis and Ritonavir inhibiting bile acid transport. Clear differences in antigen presentation were noted, with marked activation of MHC Class I by Nevirapine and suppression by Ritonavir. This suggests CD8+ T cell involvement for Nevirapine and possibly NK Killer cells for Ritonavir. Both compounds induced several drug metabolizing genes (including CYP2B6, CYP3A4 and UGT1A1), mediated by CAR activation in Nevirapine and PXR in Ritonavir. Unlike Ritonavir, Nevirapine did not increase fatty acid synthesis or activate the respiratory electron chain with simultaneous mitochondrial uncoupling supporting clinical reports of a lower propensity for steatosis. This in vitro study offers insights into the disparate direct and immune-mediated toxicity mechanisms underlying Nevirapine and Ritonavir toxicity in the clinic.
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Inhibition of ATP synthesis by fenbufen and its conjugated metabolites in rat liver mitochondria. Toxicol In Vitro 2015; 31:23-9. [PMID: 26612354 DOI: 10.1016/j.tiv.2015.11.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 11/11/2015] [Accepted: 11/19/2015] [Indexed: 11/21/2022]
Abstract
Fenbufen is an arylpropionic acid derivative belonging to the group of non-steroidal anti-inflammatory drugs (NSAIDs). Even though fenbufen is considered a safe drug, some adverse reactions including hepatic events have been reported. To investigate whether mitochondrial damage could be involved in the drug induced liver injury (DILI) by fenbufen, the inhibitory effect of fenbufen and its conjugated metabolites on oxidative phosphorylation (ATP synthesis) in rat liver mitochondria was investigated. Fenbufen glucuronide (F-GlcA), fenbufen-N-acetyl cysteine-thioester (F-NAC) and fenbufen-S-glutathione thioester (F-SG) were found to be more potent inhibitors compared to parent fenbufen (F), whereas fenbufen-O-carnitine (F-carn), fenbufen-glycine (F-gly) and fenbufen-N-acetyl lysine amide (F-NAL) were less potent compared to fenbufen. Fenbufen-CoA thioester (F-CoA) was equally potent as fenbufen in inhibiting ATP synthesis. Fenbufen showed time and concentration dependent inhibition of ATP synthesis with Kinact of 4.4 min(-1) and KI of 0.88 μM and Kinact/KI ratio of 5.01 min(-1) μM(-1). Data show that fenbufen did not act through opening MPT pore, nor did incubation of mitochondria with reduced GSH and fenbufen show any protective effect on fenbufen mediated inhibition of oxidative phosphorylation. Inclusion of NADPH in mitochondrial preparations with fenbufen did not modulate the inhibitory effects, suggesting no role of CYP mediated oxidative metabolites on the ATP synthesis in isolated mitochondria. The results from the present experiments provide evidence that fenbufen and its metabolites could be involved in mitochondrial toxicity through inhibition of ATP synthesis.
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Won JH, Park S, Hong S, Son S, Yu JW. Rotenone-induced Impairment of Mitochondrial Electron Transport Chain Confers a Selective Priming Signal for NLRP3 Inflammasome Activation. J Biol Chem 2015; 290:27425-27437. [PMID: 26416893 DOI: 10.1074/jbc.m115.667063] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Indexed: 11/06/2022] Open
Abstract
Mitochondrial dysfunction is considered crucial for NLRP3 inflammasome activation partly through its release of mitochondrial toxic products, such as mitochondrial reactive oxygen species (mROS)(2) and mitochondrial DNA (mtDNA). Although previous studies have shown that classical NLRP3-activating stimulations lead to mROS generation and mtDNA release, it remains poorly understood whether and how mitochondrial damage-derived factors may contribute to NLRP3 inflammasome activation. Here, we demonstrate that impairment of the mitochondrial electron transport chain by rotenone primes NLRP3 inflammasome activation only upon costimulation with ATP and not with nigericin or alum. Rotenone-induced priming of NLRP3 in the presence of ATP triggered the formation of specklike NLRP3 or ASC aggregates and the association of NLRP3 with ASC, resulting in NLRP3-dependent caspase-1 activation. Mechanistically, rotenone confers a priming signal for NLRP3 inflammasome activation only in the context of aberrant high-grade, but not low-grade, mROS production and mitochondrial hyperpolarization. By contrast, rotenone/ATP-mediated mtDNA release and mitochondrial depolarization are likely to be merely an indication of mitochondrial damage rather than triggering factors for NLRP3 inflammasome activation. Our results provide a molecular insight into the selective contribution made by mitochondrial dysfunction to the NLRP3 inflammasome pathway.
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Affiliation(s)
- Ji-Hee Won
- Department of Microbiology, Institute for Immunology and Immunological Diseases, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea
| | - Sangjun Park
- Department of Microbiology, Institute for Immunology and Immunological Diseases, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea
| | - Sujeong Hong
- Department of Microbiology, Institute for Immunology and Immunological Diseases, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea
| | - Seunghwan Son
- Department of Microbiology, Institute for Immunology and Immunological Diseases, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea
| | - Je-Wook Yu
- Department of Microbiology, Institute for Immunology and Immunological Diseases, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea.
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Nelms MD, Mellor CL, Cronin MTD, Madden JC, Enoch SJ. Development of an in Silico Profiler for Mitochondrial Toxicity. Chem Res Toxicol 2015; 28:1891-902. [PMID: 26375963 DOI: 10.1021/acs.chemrestox.5b00275] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
This study outlines the analysis of mitochondrial toxicity for a variety of pharmaceutical drugs extracted from Zhang et al. ((2009) Toxicol. In Vitro, 23, 134-140). These chemicals were grouped into categories based upon structural similarity. Subsequently, mechanistic analysis was undertaken for each category to identify the molecular initiating event driving mitochondrial toxicity. The mechanistic information elucidated during the analysis enabled mechanism-based structural alerts to be developed and combined together to form an in silico profiler. This profiler is envisaged to be used to develop chemical categories based upon similar mechanisms as part of the adverse outcome pathway paradigm. Additionally, the profiler could be utilized in screening large data sets in order to identify chemicals with the potential to induce mitochondrial toxicity.
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Affiliation(s)
- Mark D Nelms
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University , Byrom Street, Liverpool L3 3AF, United Kingdom
| | - Claire L Mellor
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University , Byrom Street, Liverpool L3 3AF, United Kingdom
| | - Mark T D Cronin
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University , Byrom Street, Liverpool L3 3AF, United Kingdom
| | - Judith C Madden
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University , Byrom Street, Liverpool L3 3AF, United Kingdom
| | - Steven J Enoch
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University , Byrom Street, Liverpool L3 3AF, United Kingdom
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Broom AJ, Ambroso J, Brunori G, Burns AK, Armitage JR, Francis I, Gandhi M, Peterson RA, Gant TW, Boobis AR, Lyon JJ. Effects of mid-respiratory chain inhibition on mitochondrial function in vitro and in vivo. Toxicol Res (Camb) 2015; 5:136-150. [PMID: 29780577 PMCID: PMC5941817 DOI: 10.1039/c5tx00197h] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 09/07/2015] [Indexed: 01/15/2023] Open
Abstract
Schematic showing the toxicological and adaptive effects of drug-induced respiratory chain inhibition in vivo; also highlighting unanticipated differences from observations made in vitro (in red).
Relating the in vitro mitochondrial effects of drug candidates to likely in vivo outcomes remains challenging. Better understanding of this relationship, alongside improved methods to assess mitochondrial dysfunction in vivo, would both guide safer drug candidate selection and better support discovery programmes targeting mitochondria for pharmacological intervention. The aim of this study was to profile the in vivo effects of a compound with suspected complex III electron transport chain (ETC) inhibitory activity (GSK932121A) at doses associated with clinical signs, and relate findings back to in vitro data with the same compound. Control liver mitochondria or HepG2 cells were treated in vitro with GSK932121A to assess mitochondrial effects on both calcium retention capacity (CRC) and oxygen consumption rate (OCR) respectively. The same assessments were then performed on liver mitochondria isolated from Crl:CD(SD) rats, 5 hours following intraperitoneal (IP) administration of GSK932121A. Lactate/pyruvate assessment, hepatic microscopy, blood gas analysis, glutathione profiling and transcriptomics were used to characterise the acute toxicity. In vivo, GSK932121A caused hypothermia, increased levels of hepatocellular oxidative stress and a metabolic shift in energy production, resulting in an increased lactate/pyruvate ratio, liver steatosis and glycogen depletion, together with gene expression changes indicative of a fasted state. As would be expected of an ETC inhibitor, GSK932121A reduced the CRC of liver mitochondria isolated from naive control animals and the OCR of HepG2 cells when treated directly in vitro. In contrast, mitochondria isolated from animals treated with GSK932121A in vivo unexpectedly showed an increase in CRC and basal OCR. Whilst seemingly contradictory, these differences likely reflect an adapted state in vivo resulting from the initial insult in combination with compensatory changes made by the tissue to maintain energy production. Only the initial, unconfounded, response is observable in vitro. These findings improve current understanding of the toxicological and molecular consequences of ETC inhibition. Furthermore, this work highlights key differences in the way that mitochondrial perturbation is manifest in vivo versus in vitro in terms of functional endpoints and helps guide endpoint selection for future studies with potential mitochondrial toxicants or drugs designed to modulate mitochondrial function for therapeutic benefit.
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Affiliation(s)
- Ashley J Broom
- GlaxoSmithKline , Safety Assessment , Ware , SG12 0DP , UK . ; Tel: +44 (0) 1992502345.,Imperial College London , Hammersmith Campus , London , W12 0NN , UK
| | - Jeffrey Ambroso
- GlaxoSmithKline , Safety Assessment , Research Triangle Park , North Carolina , USA
| | - Gino Brunori
- GlaxoSmithKline , Safety Assessment , Ware , SG12 0DP , UK . ; Tel: +44 (0) 1992502345
| | - Angie K Burns
- GlaxoSmithKline , Safety Assessment , Ware , SG12 0DP , UK . ; Tel: +44 (0) 1992502345
| | - James R Armitage
- GlaxoSmithKline , Safety Assessment , Ware , SG12 0DP , UK . ; Tel: +44 (0) 1992502345
| | - Ian Francis
- GlaxoSmithKline , Safety Assessment , Ware , SG12 0DP , UK . ; Tel: +44 (0) 1992502345
| | - Mitul Gandhi
- GlaxoSmithKline , Safety Assessment , Ware , SG12 0DP , UK . ; Tel: +44 (0) 1992502345
| | - Richard A Peterson
- GlaxoSmithKline , Safety Assessment , Research Triangle Park , North Carolina , USA
| | - Timothy W Gant
- Public Health England , Harwell Science and Innovation Campus , Oxfordshire , OX11 0RQ , UK
| | - Alan R Boobis
- Imperial College London , Hammersmith Campus , London , W12 0NN , UK
| | - Jonathan J Lyon
- GlaxoSmithKline , Safety Assessment , Ware , SG12 0DP , UK . ; Tel: +44 (0) 1992502345
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Mieiro CL, Pardal M, Duarte A, Pereira E, Palmeira CM. Impairment of mitochondrial energy metabolism of two marine fish by in vitro mercuric chloride exposure. MARINE POLLUTION BULLETIN 2015; 97:488-493. [PMID: 26026249 DOI: 10.1016/j.marpolbul.2015.05.054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 05/19/2015] [Accepted: 05/21/2015] [Indexed: 06/04/2023]
Abstract
The goal of this work was to understand the extent of mercury toxic effects in liver metabolism under an episode of acute contamination. Hence, the effects of in vitro mercuric chloride in liver mitochondria were assessed in two commercial marine fish: Senegalese sole (Solea senegalensis) and gilthead seabream (Sparus aurata). Liver mitochondria were exposed to 0.2mgL(-1) of mercury, the average concentration found in fish inhabiting contaminated areas. Mercuric chloride depressed mitochondrial respiration state 3 and the maximal oxygen consumption in the presence of FCCP indicating inhibitory effects on the oxidative phosphorylation and on the electron transport chain, respectively. The inhibition of F1Fo-ATPase and succinate-dehydrogenase activities also corroborated the ability of mercury to inhibit ADP phosphorylation and the electron transport chain. This study brings new understanding on the mercury levels able to impair fish mitochondrial function, reinforcing the need for further assessing bioenergetics as a proxy for fish health status.
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Affiliation(s)
- C L Mieiro
- CESAM, Department of Chemistry, University of Aveiro, Campus de Santiago, 8005-135 Aveiro, Portugal.
| | - M Pardal
- CFE, Department of Life Sciences, University of Coimbra, Apartado 3046, 3001-401 Coimbra, Portugal
| | - A Duarte
- CESAM, Department of Chemistry, University of Aveiro, Campus de Santiago, 8005-135 Aveiro, Portugal
| | - E Pereira
- CESAM, Department of Chemistry, University of Aveiro, Campus de Santiago, 8005-135 Aveiro, Portugal
| | - C M Palmeira
- CNC, Department of Life Sciences, University of Coimbra, Apartado 3046, 3001-401 Coimbra, Portugal
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Agil A, El-Hammadi M, Jiménez-Aranda A, Tassi M, Abdo W, Fernández-Vázquez G, Reiter RJ. Melatonin reduces hepatic mitochondrial dysfunction in diabetic obese rats. J Pineal Res 2015; 59:70-9. [PMID: 25904243 DOI: 10.1111/jpi.12241] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 04/20/2015] [Indexed: 12/20/2022]
Abstract
Hepatic mitochondrial dysfunction is thought to play a role in the development of liver steatosis and insulin resistance, which are both common characteristics of obesity and type 2 diabetes mellitus (T2DM). It was hypothesized that the antioxidant properties of melatonin could potentially improve the impaired functions of hepatic mitochondria in diabetic obese animals. Male Zucker diabetic fatty (ZDF) rats and lean littermates (ZL) were given either melatonin (10 mg/kg BW/day) orally for 6 wk (M-ZDF and M-ZL) or vehicle as control groups (C-ZDF and C-ZL). Hepatic function was evaluated by measurement of serum alanine transaminase and aspartate transaminase levels, liver histopathology and electron microscopy, and hepatic mitochondrial functions. Several impaired functions of hepatic mitochondria were observed in C-ZDF in comparison with C-ZL rats. Melatonin treatment to ZDF rats decreases serum levels of ALT (P < 0.001), alleviates liver steatosis and vacuolation, and also mitigates diabetic-induced mitochondrial abnormalities, glycogen, and lipid accumulation. Melatonin improves mitochondrial dysfunction in M-ZDF rats by increasing activities of mitochondrial citrate synthase (P < 0.001) and complex IV of electron transfer chain (P < 0.05) and enhances state 3 respiration (P < 0.001), respiratory control index (RCR) (P < 0.01), and phosphorylation coefficient (ADP/O ratio) (P < 0.05). Also melatonin augments ATP production (P < 0.05) and diminishes uncoupling protein 2 levels (P < 0.001). These results demonstrate that chronic oral melatonin reduces liver steatosis and mitochondria dysfunction in ZDF rats. Therefore, it may be beneficial in the treatment of diabesity.
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Affiliation(s)
- Ahmad Agil
- Department of Pharmacology and Neurosciences Institute, School of Medicine, University of Granada, Granada, Spain
| | - Mazen El-Hammadi
- Department of Pharmacology and Neurosciences Institute, School of Medicine, University of Granada, Granada, Spain
- Department of Pharmaceutics, Faculty of Pharmacy, Damascus University, Damascus, Syria
| | - Aroa Jiménez-Aranda
- Department of Pharmacology and Neurosciences Institute, School of Medicine, University of Granada, Granada, Spain
| | - Mohamed Tassi
- Service of Microscopy, CIBM, University of Granada, Granada, Spain
| | - Walied Abdo
- Department of Pharmacology and Neurosciences Institute, School of Medicine, University of Granada, Granada, Spain
- Department of pathology, Faculty of Veterinary medicine, Kafrelsheikh University, Kafrelsheikh, Egypt
| | | | - Russel J Reiter
- Department of cellular and Structural Biology, University of Texas Health Science at San Antonio, San Antonio, TX, USA
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Janssen S, Hermans S, Knap M, Moekotte A, Rossatanga EG, Adegnika AA, Bélard S, Hänscheid T, Grobusch MP. Impact of Anti-Retroviral Treatment and Cotrimoxazole Prophylaxis on Helminth Infections in HIV-Infected Patients in Lambaréné, Gabon. PLoS Negl Trop Dis 2015; 9:e0003769. [PMID: 25993501 PMCID: PMC4439024 DOI: 10.1371/journal.pntd.0003769] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 04/17/2015] [Indexed: 12/31/2022] Open
Abstract
Background Foci of the HIV epidemic and helminthic infections largely overlap geographically. Treatment options for helminth infections are limited, and there is a paucity of drug-development research in this area. Limited evidence suggests that antiretroviral therapy (ART) reduces prevalence of helminth infections in HIV-infected individuals. We investigated whether ART exposure and cotrimoxazole preventive therapy (CTX-P) is associated with a reduced prevalence of helminth infections. Methodology and Principal Findings This cross-sectional study was conducted at a primary HIV-clinic in Lambaréné, Gabon. HIV-infected adults who were ART-naïve or exposed to ART for at least 3 months submitted one blood sample and stool and urine samples on 3 consecutive days. Outcome was helminth infection with intestinal helminths, Schistosoma haematobium, Loa loa or Mansonella perstans. Multivariable logistic regression was used to assess associations between ART or CTX-P and helminth infection. In total, 408 patients were enrolled. Helminth infection was common (77/252 [30.5%]). Filarial infections were most prevalent (55/310 [17.7%]), followed by infection with intestinal helminths (35/296 [11.8%]) and S. haematobium (19/323 [5.9%]). Patients on CTX-P had a reduced risk of Loa loa microfilaremia (adjusted odds ratio (aOR) 0.47, 95% CI 0.23-0.97, P = 0.04), also in the subgroup of patients on ART (aOR 0.36, 95% CI 0.13-0.96, P = 0.04). There was no effect of ART exposure on helminth infection prevalence. Conclusions/Significance CTX-P use was associated with a decreased risk of Loa loa infection, suggesting an anthelminthic effect of antifolate drugs. No relation between ART use and helminth infections was established. The geographical distribution of helminth infections, which are highly prevalent in many areas, overlaps considerably with regions of high HIV sero-prevalence. The highest burden of infection is found in resource-poor settings, making it unattractive for the pharmaceutical industry to invest. Limited available treatment options and drug-resistance are increasing problems for soil-transmitted helminths, whereas for some other helminth infections, such as for the blood-dwelling microfilariae, effective and safe treatment options are still far from being optimal. Limited evidence suggests antihelminthic effects of antiretroviral therapy (ART) in HIV-infected individuals. We aimed to investigate whether ART or cotrimoxazole preventive treatment (CTX-P) reduces prevalence of helminth infection in HIV-infected individuals attending a primary HIV clinic in a semi-rural area in Gabon. The most important finding of our study was that the use of CTX-P was associated with a reduced prevalence of Loa loa microfilaremia. ART use was not associated with a reduced prevalence of helminth infections. Additional studies are needed to assess the effects of CTX on helminth infections, as this might be a promising safe and effective drug adding to the limited repertoire of anthelminthic drugs.
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Affiliation(s)
- Saskia Janssen
- Center for Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Centre de Traitement Ambulatoire (CTA), Lambaréné, Gabon
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
- Clinical Infectious Diseases Research Initiative, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- * E-mail:
| | - Sabine Hermans
- Desmond Tutu HIV Centre, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- Department of Global Health, Amsterdam Institute for Global Health and Development, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Department of Internal Medicine, School of Medicine, Makerere University College of Health Sciences, Kampala, Uganda
| | - Martijn Knap
- Center for Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
| | - Alma Moekotte
- Center for Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
| | | | - Akim A. Adegnika
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Sabine Bélard
- Center for Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
- Department of Pediatric Pneumology and Immunology, Charité-Universitätsmedizin, Berlin, Germany
| | - Thomas Hänscheid
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Instituto de Microbiologia, Faculdade de Medicina de Lisboa, Lisbon, Portugal
| | - Martin P. Grobusch
- Center for Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
- Clinical Infectious Diseases Research Initiative, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- Department of Global Health, Amsterdam Institute for Global Health and Development, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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Wills LP, Beeson GC, Hoover DB, Schnellmann RG, Beeson CC. Assessment of ToxCast Phase II for Mitochondrial Liabilities Using a High-Throughput Respirometric Assay. Toxicol Sci 2015; 146:226-34. [PMID: 25926417 DOI: 10.1093/toxsci/kfv085] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Previous high-throughput screens to identify mitochondrial toxicants used immortalized cell lines and focused on changes in mitochondrial membrane potential, which may not be sufficient and do not identify different types of mitochondrial dysfunction. Primary cultures of renal proximal tubule cells (RPTC) were examined with the Seahorse Extracellular Flux Analyzer to screen 676 compounds (5 μM; 1 h) from the ToxCast Phase II library for mitochondrial toxicants. Of the 676 compounds, 19 were classified as cytotoxicants, 376 were electron transport chain (ETC) inhibitors, and 5 were uncouplers. The remaining 276 compounds were examined after a 5-h exposure to identify slower acting mitochondrial toxicants. This experiment identified 3 cytotoxicants, 110 ETC inhibitors, and 163 compounds with no effect. A subset of the ToxCast Phase II library was also examined in immortalized human renal cells (HK2) to determine differences in susceptibility to mitochondrial toxicity. Of the 131 RPTC ETC inhibitors tested, only 14 were ETC inhibitors in HK2 cells. Of the 5 RPTC uncouplers, 1 compound was an uncoupler in HK2 cells. These results demonstrate that 73% (491/676) of the compounds in the ToxCast Phase II library compounds exhibit RPTC mitochondrial toxicity, overwhelmingly ETC inhibition. In contrast, renal HK2 cells are markedly less sensitive and only identified 6% of the compounds as mitochondrial toxicants. We suggest caution is needed when studying mitochondrial toxicity in immortalized cell lines. This information will provide mechanisms and chemical-based criteria for assessing and predicting mitochondrial liabilities of new drugs, consumer products, and environmental agents.
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Affiliation(s)
| | - Gyda C Beeson
- *MitoHealth Inc., Charleston, South Carolina, Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina 29425 and
| | - Douglas B Hoover
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina 29425 and
| | - Rick G Schnellmann
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina 29425 and Ralph H. Johnson Veterans Administration Medical Center, Charleston, South Carolina
| | - Craig C Beeson
- *MitoHealth Inc., Charleston, South Carolina, Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina 29425 and
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Liu R, Yu X, Wallqvist A. Data-driven identification of structural alerts for mitigating the risk of drug-induced human liver injuries. J Cheminform 2015; 7:4. [PMID: 25717346 PMCID: PMC4339691 DOI: 10.1186/s13321-015-0053-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 01/27/2015] [Indexed: 12/12/2022] Open
Abstract
Background The use of structural alerts to de-prioritize compounds with undesirable features as drug candidates has been gaining in popularity. Hundreds of molecular structural moieties have been proposed as structural alerts. An emerging issue is that strict application of these alerts will result in a significant reduction of the chemistry space for new drug discovery, as more than half of the oral drugs on the market match at least one of the alerts. To mitigate this issue, we propose to apply a rigorous statistical analysis to derive/validate structural alerts before use. Method To derive human liver toxicity structural alerts, we retrieved all small-molecule entries from LiverTox, a U.S. National Institutes of Health online resource for information on human liver injuries induced by prescription and over-the-counter drugs and dietary supplements. We classified the compounds into hepatotoxic, nonhepatotoxic, and possible hepatotoxic classes, and performed detailed statistical analyses to identify molecular structural fragments highly enriched in the hepatotoxic class beyond random distribution as structural alerts for human liver injuries. Results We identified 12 molecular fragments present in multiple marketed drugs that one can consider as common “drug-like” fragments, yet they are strongly associated with drug-induced human liver injuries. Thus, these fragments may be considered as robust hepatotoxicity structural alerts suitable for use in drug discovery screening programs. Conclusions The use of structural alerts has contributed to the identification of many compounds with potential toxicity issues in modern drug discovery. However, with a large number of structural alerts published to date without proper validation, application of these alerts may restrict the chemistry space and prevent discovery of valuable drugs. To mitigate this issue, we showed how to use statistical analyses to develop a small, robust, and broadly applicable set of structural alerts. Hepatotoxic-specific filters for flagging high risk compounds. ![]()
Electronic supplementary material The online version of this article (doi:10.1186/s13321-015-0053-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ruifeng Liu
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, 2405 Whittier Drive, Frederick, MD 21702 USA
| | - Xueping Yu
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, 2405 Whittier Drive, Frederick, MD 21702 USA
| | - Anders Wallqvist
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, 2405 Whittier Drive, Frederick, MD 21702 USA
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62
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The protective effect of Moringa oleifera leaves against cyclophosphamide-induced urinary bladder toxicity in rats. Tissue Cell 2015; 47:94-104. [DOI: 10.1016/j.tice.2014.12.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Revised: 12/07/2014] [Accepted: 12/09/2014] [Indexed: 11/21/2022]
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63
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Imaizumi N, Kwang Lee K, Zhang C, Boelsterli UA. Mechanisms of cell death pathway activation following drug-induced inhibition of mitochondrial complex I. Redox Biol 2015; 4:279-88. [PMID: 25625582 PMCID: PMC4315936 DOI: 10.1016/j.redox.2015.01.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 01/03/2015] [Accepted: 01/07/2015] [Indexed: 11/02/2022] Open
Abstract
Respiratory complex I inhibition by drugs and other chemicals has been implicated as a frequent mode of mitochondria-mediated cell injury. However, the exact mechanisms leading to the activation of cell death pathways are incompletely understood. This study was designed to explore the relative contributions to cell injury of three distinct consequences of complex I inhibition, i.e., impairment of ATP biosynthesis, increased formation of superoxide and, hence, peroxynitrite, and inhibition of the mitochondrial protein deacetylase, Sirt3, due to imbalance of the NADH/NAD(+) ratio. We used the antiviral drug efavirenz (EFV) to model drug-induced complex I inhibition. Exposure of cultured mouse hepatocytes to EFV resulted in a rapid onset of cell injury, featuring a no-effect level at 30µM EFV and submaximal effects at 50µM EFV. EFV caused a concentration-dependent decrease in cellular ATP levels. Furthermore, EFV resulted in increased formation of peroxynitrite and oxidation of mitochondrial protein thiols, including cyclophilin D (CypD). This was prevented by the superoxide scavenger, Fe-TCP, or the peroxynitrite decomposition catalyst, Fe-TMPyP. Both ferroporphyrins completely protected from EFV-induced cell injury, suggesting that peroxynitrite contributed to the cell injury. Finally, EFV increased the NADH/NAD(+) ratio, inhibited Sirt3 activity, and led to hyperacetylated lysine residues, including those in CypD. However, hepatocytes isolated from Sirt3-null mice were protected against 40µM EFV as compared to their wild-type controls. In conclusion, these data are compatible with the concept that chemical inhibition of complex I activates multiple pathways leading to cell injury; among these, peroxynitrite formation may be the most critical.
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Affiliation(s)
- Naoki Imaizumi
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269, USA; Laboratory of Molecular Genetics, School of Health Sciences, Faculty of Medicine, University of the Ryukyus, Okinawa 903-0215, Japan.
| | - Kang Kwang Lee
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269, USA
| | - Carmen Zhang
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269, USA
| | - Urs A Boelsterli
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269, USA
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64
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González-Durruthy M, Monserrat JM, Alberici LC, Naal Z, Curti C, González-Díaz H. Mitoprotective activity of oxidized carbon nanotubes against mitochondrial swelling induced in multiple experimental conditions and predictions with new expected-value perturbation theory. RSC Adv 2015. [DOI: 10.1039/c5ra14435c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Mitochondrial Permeability Transition Pore (MPTP) is involved in neurodegeneration, hepatotoxicity, cardiac necrosis, nervous and muscular dystrophies.
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Affiliation(s)
- Michael González-Durruthy
- Institute of Biological Science (ICB)
- Universidade Federal do Rio Grande (FURG)
- Porto Alegre
- Brazil
- ICB-FURG Post-graduate Program Physiological Sciences – Comparative Animal Physiology, Brazil
| | - Jose Maria Monserrat
- Institute of Biological Science (ICB)
- Universidade Federal do Rio Grande (FURG)
- Porto Alegre
- Brazil
- ICB-FURG Post-graduate Program Physiological Sciences – Comparative Animal Physiology, Brazil
| | - Luciane C. Alberici
- Department of Physic-Chemistry
- Faculty of Pharmacy of Ribeirão Preto
- University of São Paulo (USP)
- 14040-903 Ribeirão Preto
- Brazil
| | - Zeki Naal
- Department of Physic-Chemistry
- Faculty of Pharmacy of Ribeirão Preto
- University of São Paulo (USP)
- 14040-903 Ribeirão Preto
- Brazil
| | - Carlos Curti
- Department of Physic-Chemistry
- Faculty of Pharmacy of Ribeirão Preto
- University of São Paulo (USP)
- 14040-903 Ribeirão Preto
- Brazil
| | - Humberto González-Díaz
- Department of Organic Chemistry II
- Faculty of Science and Technology
- University of the Basque Country UPV/EHU
- Leioa
- Spain
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65
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Piel S, Ehinger JK, Elmér E, Hansson MJ. Metformin induces lactate production in peripheral blood mononuclear cells and platelets through specific mitochondrial complex I inhibition. Acta Physiol (Oxf) 2015; 213:171-80. [PMID: 24801139 DOI: 10.1111/apha.12311] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 11/21/2013] [Accepted: 04/26/2014] [Indexed: 12/25/2022]
Abstract
AIM Metformin is a widely used antidiabetic drug associated with the rare side effect of lactic acidosis which has been proposed to be linked to drug-induced mitochondrial dysfunction. Using respirometry, the aim of this study was to evaluate mitochondrial toxicity of metformin to human blood cells in relation to that of phenformin, a biguanide analogue withdrawn in most countries due to a high incidence of lactic acidosis. METHODS Peripheral blood mononuclear cells and platelets were isolated from healthy volunteers, and integrated mitochondrial function was studied in permeabilized and intact cells using high-resolution respirometry. A wide concentration range of metformin (0.1-100 mm) and phenformin (25-500 μm) was investigated for dose- and time-dependent effects on respiratory capacities, lactate production and pH. RESULTS Metformin induced respiratory inhibition at complex I in peripheral blood mononuclear cells and platelets (IC50 0.45 mm and 1.2 mm respectively). Phenformin was about 20-fold more potent in complex I inhibition of platelets than metformin. Metformin further demonstrated a dose- and time-dependent respiratory inhibition and augmented lactate release at a concentration of 1 mm and higher. CONCLUSION Respirometry of human peripheral blood cells readily detected respiratory inhibition by metformin and phenformin specific to complex I, providing a suitable model for probing drug toxicity. Lactate production was increased at concentrations relevant for clinical metformin intoxication, indicating mitochondrial inhibition as a direct causative pathophysiological mechanism. Relative to clinical dosing, phenformin displayed a more potent respiratory inhibition than metformin, possibly explaining the higher incidence of lactic acidosis in phenformin-treated patients.
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Affiliation(s)
- S. Piel
- Mitochondrial Medicine; Department of Clinical Sciences; Lund University; Lund Sweden
- NeuroVive Pharmaceutical AB; Lund Sweden
| | - J. K. Ehinger
- Mitochondrial Medicine; Department of Clinical Sciences; Lund University; Lund Sweden
- NeuroVive Pharmaceutical AB; Lund Sweden
- Department of Otorhinolaryngology; Head and Neck Surgery; Skåne University Hospital; Lund Sweden
| | - E. Elmér
- Mitochondrial Medicine; Department of Clinical Sciences; Lund University; Lund Sweden
- NeuroVive Pharmaceutical AB; Lund Sweden
- Department of Clinical Neurophysiology; Skåne University Hospital & Lund University; Lund Sweden
| | - M. J. Hansson
- Mitochondrial Medicine; Department of Clinical Sciences; Lund University; Lund Sweden
- NeuroVive Pharmaceutical AB; Lund Sweden
- Department of Clinical Physiology; Skåne University Hospital & Lund University; Lund Sweden
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66
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How to mechanistically explain the CONDOR study data. Med Hypotheses 2014; 84:14-9. [PMID: 25433956 DOI: 10.1016/j.mehy.2014.11.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 11/04/2014] [Accepted: 11/09/2014] [Indexed: 02/02/2023]
Abstract
Results of the CONDOR study suggest that in osteoarthritis and rheumatoid arthritis patients at elevated risk of gastrointestinal (GI) events, treatment with celecoxib, a cyclooxygenase (COX)-2 selective non-steroidal anti-inflammatory drug (NSAID), demonstrated significantly lower toxicity in the upper and lower (GI) tract when compared to the non-selective NSAID diclofenac plus a proton-pump-inhibitor (PPI), omeprazole. According to current knowledge, traditional NSAIDs (tNSAIDs) as non-selective COX-inhibitors exert their damaging effects on the upper GI tract, largely by reduction of the COX-1 related synthesis of gastro-protective prostaglandins. Thus, the question arises, how NSAIDs do exert their damaging effects especially in the lower GI tract and how to explain the reduced risk of a COX-2 selective inhibitor, celecoxib. Here we hypothesize, that the toxicity of celecoxib on enteral mucosa cells is lower than observed with other NSAIDs, and can be explained COX-independently by typical physicochemical properties of the NSAID substances (e.g., acidic, lipophilic, amphiphilic, surfactant properties). As a consequence these features account for differences in (1) uncoupling effects on mitochondria, (2) effects on cell membrane integrity, and/or (3) formation of "toxic micelles" with bile salts. The evidence for these differences is mainly based on experimental findings. However, several phenomena show differences in extent (e.g., uncoupling effects). The reduced toxicity appears to be rather a substance-specific characteristic. This is an unconditional reason to carry on investigating these phenomena in experimental and large-scale clinical trials.
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67
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Esteves AR, G-Fernandes M, Santos D, Januário C, Cardoso SM. The Upshot of LRRK2 Inhibition to Parkinson’s Disease Paradigm. Mol Neurobiol 2014; 52:1804-1820. [DOI: 10.1007/s12035-014-8980-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 10/31/2014] [Indexed: 12/13/2022]
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Wang R, Novick SJ, Mangum JB, Queen K, Ferrick DA, Rogers GW, Stimmel JB. The acute extracellular flux (XF) assay to assess compound effects on mitochondrial function. ACTA ACUST UNITED AC 2014; 20:422-9. [PMID: 25381255 DOI: 10.1177/1087057114557621] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
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.
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Affiliation(s)
- Ruolan Wang
- GlaxoSmithKline, Research Triangle Park, NC, USA
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69
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Li N, Oquendo E, Capaldi RA, Robinson JP, He YD, Hamadeh HK, Afshari CA, Lightfoot-Dunn R, Narayanan PK. A systematic assessment of mitochondrial function identified novel signatures for drug-induced mitochondrial disruption in cells. Toxicol Sci 2014; 142:261-73. [PMID: 25163676 DOI: 10.1093/toxsci/kfu176] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Mitochondrial perturbation has been recognized as a contributing factor to various drug-induced organ toxicities. To address this issue, we developed a high-throughput flow cytometry-based mitochondrial signaling assay to systematically investigate mitochondrial/cellular parameters known to be directly impacted by mitochondrial dysfunction: mitochondrial membrane potential (MMP), mitochondrial reactive oxygen species (ROS), intracellular reduced glutathione (GSH) level, and cell viability. Modulation of these parameters by a training set of compounds, comprised of established mitochondrial poisons and 60 marketed drugs (30 nM to 1mM), was tested in HL-60 cells (a human pro-myelocytic leukemia cell line) cultured in either glucose-supplemented (GSM) or glucose-free (containing galactose/glutamine; GFM) RPMI-1640 media. Post-hoc bio-informatic analyses of IC50 or EC50 values for all parameters tested revealed that MMP depolarization in HL-60 cells cultured in GSM was the most reliable parameter for determining mitochondrial dysfunction in these cells. Disruptors of mitochondrial function depolarized MMP at concentrations lower than those that caused loss of cell viability, especially in cells cultured in GSM; cellular GSH levels correlated more closely to loss of viability in vitro. Some mitochondrial respiratory chain inhibitors increased mitochondrial ROS generation; however, measuring an increase in ROS alone was not sufficient to identify mitochondrial disruptors. Furthermore, hierarchical cluster analysis of all measured parameters provided confirmation that MMP depletion, without loss of cell viability, was the key signature for identifying mitochondrial disruptors. Subsequent classification of compounds based on ratios of IC50s of cell viability:MMP determined that this parameter is the most critical indicator of mitochondrial health in cells and provides a powerful tool to predict whether novel small molecule entities possess this liability.
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Affiliation(s)
- Nianyu Li
- Department of Comparative Biology and Safety Sciences, Amgen, Amgen Court West 1201, Seattle, Washington 98119
| | | | | | - J Paul Robinson
- Purdue University Cytometry Laboratories, Department of Basic Medical Sciences, Purdue University, West Lafayette, Indiana 47907
| | - Yudong D He
- Department of Comparative Biology and Safety Sciences, Amgen, Amgen Court West 1201, Seattle, Washington 98119
| | - Hisham K Hamadeh
- Department of Comparative Biology and Safety Sciences, Amgen, 1 Amgen Center Dr, Thousand Oaks, California 91320-1799
| | - Cynthia A Afshari
- Department of Comparative Biology and Safety Sciences, Amgen, 1 Amgen Center Dr, Thousand Oaks, California 91320-1799
| | - Ruth Lightfoot-Dunn
- Department of Comparative Biology and Safety Sciences, Amgen, 1 Amgen Center Dr, Thousand Oaks, California 91320-1799
| | - Padma Kumar Narayanan
- Department of Comparative Biology and Safety Sciences, Amgen, Amgen Court West 1201, Seattle, Washington 98119
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Nelms MD, Ates G, Madden JC, Vinken M, Cronin MTD, Rogiers V, Enoch SJ. Proposal of an in silico profiler for categorisation of repeat dose toxicity data of hair dyes. Arch Toxicol 2014; 89:733-41. [PMID: 24888375 DOI: 10.1007/s00204-014-1277-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 05/19/2014] [Indexed: 12/20/2022]
Abstract
This study outlines the analysis of 94 chemicals with repeat dose toxicity data taken from Scientific Committee on Consumer Safety opinions for commonly used hair dyes in the European Union. Structural similarity was applied to group these chemicals into categories. Subsequent mechanistic analysis suggested that toxicity to mitochondria is potentially a key driver of repeat dose toxicity for chemicals within each of the categories. The mechanistic hypothesis allowed for an in silico profiler consisting of four mechanism-based structural alerts to be proposed. These structural alerts related to a number of important chemical classes such as quinones, anthraquinones, substituted nitrobenzenes and aromatic azos. This in silico profiler is intended for grouping chemicals into mechanism-based categories within the adverse outcome pathway paradigm.
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Affiliation(s)
- M D Nelms
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK
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71
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Zlatković J, Todorović N, Tomanović N, Bošković M, Djordjević S, Lazarević-Pašti T, Bernardi RE, Djurdjević A, Filipović D. Chronic administration of fluoxetine or clozapine induces oxidative stress in rat liver: a histopathological study. Eur J Pharm Sci 2014; 59:20-30. [PMID: 24768740 DOI: 10.1016/j.ejps.2014.04.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 02/28/2014] [Accepted: 04/13/2014] [Indexed: 12/16/2022]
Abstract
Chronic exposure to stress contributes to the etiology of mood disorders, and the liver as a target organ of antidepressant and antipsychotic drug metabolism is vulnerable to drug-induced toxicity. We investigated the effects of chronic administration of fluoxetine (15mg/kg/day) or clozapine (20mg/kg/day) on liver injury via the measurement of liver enzymes, oxidative stress and histopathology in rats exposed to chronic social isolation (21days), an animal model of depression, and controls. The activity of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), the liver content of carbonyl groups, malonyldialdehyde (MDA), reduced glutathione (GSH), cytosolic glutathione S-transferase (GST) and nitric oxide (NO) metabolites were determined. We also characterized nuclear factor-κB (NF-κB), cyclooxygenase-2 (COX-2) and CuZn-superoxide dismutase (CuZnSOD) protein expression as well as histopathological changes. Increased serum ALT activity in chronically-isolated and control animals treated with both drugs was found while increased AST activity was observed only in fluoxetine-treated rats (chronically-isolated and controls). Increased carbonyl content, MDA, GST activity and decreased GSH levels in drug-treated controls/chronically-isolated animals suggest a link between drugs and hepatic oxidative stress. Increased NO levels associated with NF-κB activation and the concomitant increased COX-2 expression together with compromised CuZnSOD expression in clozapine-treated chronically-isolated rats likely reinforce oxidative stress, observed by increased lipid peroxidation and GSH depletion. In contrast, fluoxetine reduced NO levels in chronically-isolated rats. Isolation induced oxidative stress but histological changes were similar to those observed in vehicle-treated controls. Chronic administration of fluoxetine in both chronically-isolated and control animals resulted in more or less normal hepatic architecture, while clozapine in both groups resulted in liver injury. These data suggest that clozapine appears to have a higher potential to induce liver toxicity than fluoxetine.
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Affiliation(s)
- Jelena Zlatković
- Laboratory of Molecular Biology and Endocrinology, Institute of Nuclear Sciences "Vinča", University of Belgrade, Serbia
| | - Nevena Todorović
- Laboratory of Molecular Biology and Endocrinology, Institute of Nuclear Sciences "Vinča", University of Belgrade, Serbia
| | - Nada Tomanović
- Institute of Pathology, School of Medicine, University of Belgrade, Serbia
| | - Maja Bošković
- Laboratory of Molecular Biology and Endocrinology, Institute of Nuclear Sciences "Vinča", University of Belgrade, Serbia
| | | | - Tamara Lazarević-Pašti
- Department of Physical Chemistry, Institute of Nuclear Sciences "Vinča", University of Belgrade, Serbia
| | - Rick E Bernardi
- Central Institute of Mental Health, Institute of Psychopharmacology, Mannheim, Germany
| | | | - Dragana Filipović
- Laboratory of Molecular Biology and Endocrinology, Institute of Nuclear Sciences "Vinča", University of Belgrade, Serbia.
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Lee KK, Boelsterli UA. Bypassing the compromised mitochondrial electron transport with methylene blue alleviates efavirenz/isoniazid-induced oxidant stress and mitochondria-mediated cell death in mouse hepatocytes. Redox Biol 2014; 2:599-609. [PMID: 25460728 PMCID: PMC4297936 DOI: 10.1016/j.redox.2014.03.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 03/11/2014] [Indexed: 11/03/2022] Open
Abstract
Efavirenz (EFV) is an anti-retroviral drug frequently combined with isoniazid (INH) to treat HIV-1/tuberculosis co-infected patients. Both drugs have been associated with idiosyncratic liver injury (DILI), but combined anti-retroviral and anti-tubercular therapy can increase the risk for DILI as compared to either drug class alone. Because both EFV and INH have been implicated in targeting mitochondria, we aimed at exploring whether the two drugs might cause synergistic effects on the electron transport chain. We found that EFV inhibited complex I activity in isolated mouse liver mitochondria (IC50 ˜30 μM), whereas hydrazine, a major metabolite of INH generated by acylamidase-mediated hydrolytic cleavage, inhibited complex II activity (IC50 ˜30 μM). Neither INH alone (≤1000 μM) nor EFV alone (≤30 μM) was able to induce cell injury in cultured mouse hepatocytes. However, combined EFV/INH exposure resulted in increased superoxide formation and peroxynitrite stress, leading to the opening of the cyclosporine A-insensitive mode of the mitochondrial permeability transition (mPT), and necrotic cell death. The peroxynitrite scavengers, CBA or Fe-TMPyP, protected against mPT induction and alleviated cell injury. The acylamidase inhibitor bis-p-nitrophenyl phosphate prevented cell injury, suggesting that hydrazine greatly contributed to the toxicity. Methylene blue, a redox-active alternative electron acceptor/donor that bypasses complex I/II, effectively protected against EFV/INH-induced toxicity. These data demonstrate that, in murine hepatocytes, the mitochondrial electron transport chain is a critical target of combined EFV/INH exposure, and that this drug combination can lead to peroxynitrite stress-induced mPT and hepatocellular necrosis. These results are compatible with the concept that underlying silent mitochondrial dysfunction may be a key susceptibility factor contributing to idiosyncratic drug-induced liver injury.
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Affiliation(s)
- Kang Kwang Lee
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269, United States of America
| | - Urs A Boelsterli
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269, United States of America.
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Datta S, Mahdi F, Ali Z, Jekabsons MB, Khan IA, Nagle DG, Zhou YD. Toxins in botanical dietary supplements: blue cohosh components disrupt cellular respiration and mitochondrial membrane potential. JOURNAL OF NATURAL PRODUCTS 2014; 77:111-117. [PMID: 24328138 PMCID: PMC3932489 DOI: 10.1021/np400758t] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Certain botanical dietary supplements have been associated with idiosyncratic organ-specific toxicity. Similar toxicological events, caused by drug-induced mitochondrial dysfunction, have forced the withdrawal or U.S. FDA "black box" warnings of major pharmaceuticals. To assess the potential mitochondrial liability of botanical dietary supplements, extracts from 352 authenticated plant samples used in traditional Chinese, Ayurvedic, and Western herbal medicine were evaluated for the ability to disrupt cellular respiration. Blue cohosh (Caulophyllum thalictroides) methanol extract exhibited mitochondriotoxic activity. Used by some U.S. midwives to help induce labor, blue cohosh has been associated with perinatal stroke, acute myocardial infarction, congestive heart failure, multiple organ injury, and neonatal shock. The potential link between mitochondrial disruption and idiosyncratic herbal intoxication prompted further examination. The C. thalictroides methanol extract and three saponins, cauloside A (1), saponin PE (2), and cauloside C (3), exhibited concentration- and time-dependent mitochondriotoxic activities. Upon treatment, cell respiration rate rapidly increased and then dramatically decreased within minutes. Mechanistic studies revealed that C. thalictroides constituents impair mitochondrial function by disrupting membrane integrity. These studies provide a potential etiological link between this mitochondria-sensitive form of cytotoxicity and idiosyncratic organ damage.
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Affiliation(s)
- Sandipan Datta
- Department of Pharmacognosy, University of Mississippi, University, Mississippi 38677, United States
| | - Fakhri Mahdi
- Department of Pharmacognosy, University of Mississippi, University, Mississippi 38677, United States
| | - Zulfiqar Ali
- National Center for Natural Products Research, University of Mississippi, University, Mississippi 38677, United States
| | - Mika B. Jekabsons
- Department of Biology, University of Mississippi, University, Mississippi 38677, United States
| | - Ikhlas A. Khan
- Department of Pharmacognosy, University of Mississippi, University, Mississippi 38677, United States
- National Center for Natural Products Research, University of Mississippi, University, Mississippi 38677, United States
- Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi, University, Mississippi 38677, United States
| | - Dale G. Nagle
- Department of Pharmacognosy, University of Mississippi, University, Mississippi 38677, United States
- Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi, University, Mississippi 38677, United States
| | - Yu-Dong Zhou
- Department of Pharmacognosy, University of Mississippi, University, Mississippi 38677, United States
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Modulation of mitochondrial bioenergetics in a skeletal muscle cell line model of mitochondrial toxicity. Redox Biol 2014; 2:224-33. [PMID: 24494197 PMCID: PMC3909783 DOI: 10.1016/j.redox.2013.12.028] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 12/24/2013] [Accepted: 12/24/2013] [Indexed: 12/03/2022] Open
Abstract
Mitochondrial toxicity is increasingly being implicated as a contributing factor to many xenobiotic-induced organ toxicities, including skeletal muscle toxicity. This has necessitated the need for predictive in vitro models that are able to sensitively detect mitochondrial toxicity of chemical entities early in the research and development process. One such cell model involves substituting galactose for glucose in the culture media. Since cells cultured in galactose are unable to generate sufficient ATP from glycolysis they are forced to rely on mitochondrial oxidative phosphorylation for ATP generation and consequently are more sensitive to mitochondrial perturbation than cells grown in glucose. The aim of this study was to characterise cellular growth, bioenergetics and mitochondrial toxicity of the L6 rat skeletal muscle cell line cultured in either high glucose or galactose media. L6 myoblasts proliferated more slowly when cultured in galactose media, although they maintained similar levels of ATP. Galactose cultured L6 cells were significantly more sensitive to classical mitochondrial toxicants than glucose-cultured cells, confirming the cells had adapted to galactose media. Analysis of bioenergetic function with the XF Seahorse extracellular flux analyser demonstrated that oxygen consumption rate (OCR) was significantly increased whereas extracellular acidification rate (ECAR), a measure of glycolysis, was decreased in cells grown in galactose. Mitochondria operated closer to state 3 respiration and had a lower mitochondrial membrane potential and basal mitochondrial O2•– level compared to cells in the glucose model. An antimycin A (AA) dose response revealed that there was no difference in the sensitivity of OCR to AA inhibition between glucose and galactose cells. Importantly, cells in glucose were able to up-regulate glycolysis, while galactose cells were not. These results confirm that L6 cells are able to adapt to growth in a galactose media model and are consequently more susceptible to mitochondrial toxicants. L6 cells grown in glucose and galactose as model to detect skeletal muscle mitochondrial toxicity. L6 cells grown in galactose rely on mitochondrial oxidative phosphorylation for ATP production. Galactose cells are unable to use glycolysis to produce ATP following mitochondrial inhibition.
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Key Words
- AA, antimycin A
- ANT, adenine nucleotide translocase
- CPD, cumulative population doublings
- ECAR, extracellular acidification rate
- ETC, electron transport chain
- Extracellular flux analysis
- FCCP, Carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone
- FSC, forward scatter
- Galactose
- Mitochondria
- O2•–, superoxide
- OCR, oxygen consumption rate
- OXPHOS, oxidative phosphorylation
- Oligo, oligomycin
- PD, population doublings
- PPP, pentose phosphate pathway
- RCR, respiratory control ratio
- SSC, side scatter
- Skeletal muscle toxicity
- TCA, tricarboxylic acid cycle
- UCPs, uncoupling proteins
- XF, extracellular flux
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75
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Persson M, Løye AF, Mow T, Hornberg JJ. A high content screening assay to predict human drug-induced liver injury during drug discovery. J Pharmacol Toxicol Methods 2013; 68:302-13. [DOI: 10.1016/j.vascn.2013.08.001] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 07/03/2013] [Accepted: 08/01/2013] [Indexed: 12/11/2022]
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76
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Ahuja V, Sharma S. Drug safety testing paradigm, current progress and future challenges: an overview. J Appl Toxicol 2013; 34:576-94. [PMID: 24777877 DOI: 10.1002/jat.2935] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 08/08/2013] [Accepted: 08/22/2013] [Indexed: 12/29/2022]
Abstract
Early assessment of the toxicity potential of new molecules in pharmaceutical industry is a multi-dimensional task involving predictive systems and screening approaches to aid in the optimization of lead compounds prior to their entry into development phase. Due to the high attrition rate in the pharma industry in last few years, it has become imperative for the nonclinical toxicologist to focus on novel approaches which could be helpful for early screening of drug candidates. The need is that the toxicologists should change their classical approach to a more investigative approach. This review discusses the developments that allow toxicologists to anticipate safety problems and plan ways to address them earlier than ever before. This includes progress in the field of in vitro models, surrogate models, molecular toxicology, 'omics' technologies, translational safety biomarkers, stem-cell based assays and preclinical imaging. The traditional boundaries between teams focusing on efficacy/ safety and preclinical/ clinical aspects in the pharma industry are disappearing, and translational research-centric organizations with a focused vision of bringing drugs forward safely and rapidly are emerging. Today's toxicologist should collaborate with medicinal chemists, pharmacologists, and clinicians and these value-adding contributions will change traditional toxicologists from side-effect identifiers to drug development enablers.
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Affiliation(s)
- Varun Ahuja
- Drug Safety Assessment, Novel Drug Discovery and Development, Lupin Limited (Research Park), 46A/47A, Nande Village, MulshiTaluka, Pune, 412 115, India
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77
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Monteiro JP, Silva AM, Jurado AS, Oliveira PJ. Rapeseed oil-rich diet alters in vitro menadione and nimesulide hepatic mitochondrial toxicity. Food Chem Toxicol 2013; 60:479-87. [DOI: 10.1016/j.fct.2013.07.073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 07/25/2013] [Accepted: 07/27/2013] [Indexed: 11/16/2022]
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78
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Swiss R, Niles A, Cali JJ, Nadanaciva S, Will Y. Validation of a HTS-amenable assay to detect drug-induced mitochondrial toxicity in the absence and presence of cell death. Toxicol In Vitro 2013; 27:1789-97. [DOI: 10.1016/j.tiv.2013.05.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 05/20/2013] [Accepted: 05/21/2013] [Indexed: 02/08/2023]
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79
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Hewitt M, Enoch SJ, Madden JC, Przybylak KR, Cronin MTD. Hepatotoxicity: A scheme for generating chemical categories for read-across, structural alerts and insights into mechanism(s) of action. Crit Rev Toxicol 2013; 43:537-58. [DOI: 10.3109/10408444.2013.811215] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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80
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Wills LP, Beeson GC, Trager RE, Lindsey CC, Beeson CC, Peterson YK, Schnellmann RG. High-throughput respirometric assay identifies predictive toxicophore of mitochondrial injury. Toxicol Appl Pharmacol 2013; 272:490-502. [PMID: 23811330 DOI: 10.1016/j.taap.2013.06.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 06/14/2013] [Accepted: 06/18/2013] [Indexed: 11/29/2022]
Abstract
Many environmental chemicals and drugs negatively affect human health through deleterious effects on mitochondrial function. Currently there is no chemical library of mitochondrial toxicants, and no reliable methods for predicting mitochondrial toxicity. We hypothesized that discrete toxicophores defined by distinct chemical entities can identify previously unidentified mitochondrial toxicants. We used a respirometric assay to screen 1760 compounds (5 μM) from the LOPAC and ChemBridge DIVERSet libraries. Thirty-one of the assayed compounds decreased uncoupled respiration, a stress test for mitochondrial dysfunction, prior to a decrease in cell viability and reduced the oxygen consumption rate in isolated mitochondria. The mitochondrial toxicants were grouped by chemical similarity and two clusters containing four compounds each were identified. Cheminformatic analysis of one of the clusters identified previously uncharacterized mitochondrial toxicants from the ChemBridge DIVERSet. This approach will enable the identification of mitochondrial toxicants and advance the prediction of mitochondrial toxicity for both drug discovery and risk assessment.
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81
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Adipogenic/lipid, inflammatory, and mitochondrial parameters in subcutaneous adipose tissue of untreated HIV-1-infected long-term nonprogressors: significant alterations despite low viral burden. J Acquir Immune Defic Syndr 2012; 61:131-7. [PMID: 22580565 DOI: 10.1097/qai.0b013e31825c3a68] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND HIV-1 can induce disturbances in adipose tissue in infected subjects through the effects of some of its proteins or inflammation. It is not known whether this also takes place in HIV-1-infected long-term nonprogressors (LTNPs). Our objectives were to determine whether adipocyte differentiation/lipid, inflammatory, and mitochondrial parameters are perturbed in abdominal wall subcutaneous adipose tissue of untreated HIV-1-infected patients LTNPs. METHODS Cross-sectional study involving 10 LTNPs, 10 typical progressors (TPs), and 10 uninfected controls (UCs). The parameters assessed were peroxisome proliferator-activated receptor-gamma (PPARγ), lipoprotein lipase, and fatty acid-binding protein 4 mRNA (adipogenic/lipid); tumor necrosis factor-alpha, interleukin 18 (IL-18), β2-MCG, monocyte chemoattractant protein 1, CD1A, and C3 mRNA (inflammation); and cytochrome c oxidase subunit II (COII), COIV, CYCA, nuclear respiratory factor 1, PPARγ coactivator 1α mRNA, and mtDNA content (mitochondrial). RESULTS Regarding adipogenic/lipid parameters, LTNPs had PPARγ, lipoprotein lipase, and fatty acid-binding protein 4 mRNA significantly decreased compared with UCs (P ≤ 0.001 for all comparisons). PPARγ mRNA was significantly greater in LTNP than in TP (P = 0.006). With respect to inflammatory parameters, tumor necrosis factor-alpha, IL-18, and β2-MCG mRNA were significantly higher in LTNPs compared with UCs (P < 0.005 for all comparisons), whereas IL-18 mRNA was greater in TPs compared with LTNPs (P = 0.01). As mitochondrial parameters are concerned, mtDNA was significantly reduced in LTNPs compared with TPs (P = 0.04) and UCs (P = 0.03). COII and COIV were also significantly reduced in LTNPs compared with UCs and TPs. CONCLUSIONS Adipose tissue from untreated LTNPs may have limited but significant derangements in some adipogenic/lipid and may have inflammatory processes at a lower degree than that observed in untreated TPs. LTNPs may have mitochondrial-related alterations in adipose tissue which are greater than that observed in TPs.
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82
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Vickers AEM, Fisher RL. Evaluation of drug-induced injury and human response in precision-cut tissue slices. Xenobiotica 2012; 43:29-40. [PMID: 23094640 DOI: 10.3109/00498254.2012.732714] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
1.Drug induced organ injury is multifaceted, encompassing a spectrum of cell types and numerous networks reflecting cell-cell and cell-matrix interactions. Characterization of drug induced side effects and human response can be addressed in organ slice models. 2.The application of human tissue to various organ slice models including liver, intestine, kidney, liver-blood co-cultures and thyroid enhances our ability to focus on the clinical relevance of side effects identified in animal studies for human, and to evaluate potential biomarkers of the side effects. Dose-response relationships can help discern drug concentrations which alter organ function or affect morphology, to identify drug concentrationswhich could pose a risk for humans. 3.Insight into pathways of organ injury, by incorporating gene and protein expression profiling, with functional measurements and morphology, aid to define species differences and sensitivity. 4.Human organ slice studies are valuable for bridging the extrapolation of animal derived data and for identifying mechanisms relevant for humans, thereby expanding the scope of translational research for drug safety assessment.
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83
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Swart C, Olivier A, Dithebe K, Pohl C, van Wyk P, Swart H, Coetsee E, Kock L. Yeast sensors for novel drugs: chloroquine and others revealed. SENSORS 2012. [PMID: 23201985 PMCID: PMC3545556 DOI: 10.3390/s121013058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In this study the mitochondrion is regarded as a target to reveal compounds that may be used to combat various diseases. Consequently, the sexual structures of yeasts (with high mitochondrial activity) were identified as sensors to screen for various anti-mitochondrial drugs that may be toxic to humans and that are directed, amongst others, against fungal diseases and cancer. Strikingly, these sensors indicated that chloroquine is a potent pro-mitochondrial drug which stimulated yeast sexual reproduction. In addition, these sensors also showed that some Non-Steroidal Anti-Inflammatory drugs (NSAIDs), anti-malarial drugs, antifungal and anticancer drugs are anti-mitochondrial. These yeast sensor bio-assays may fast track studies aimed at discovering new drugs as well as their mechanisms and should now be further evaluated for selectivity towards anti-/ pro-mitochondrials, fertility drugs and contraceptives, using in vitro, in vivo, in silico and omics research.
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Affiliation(s)
- Chantel Swart
- UNESCO MIRCEN: Microbial, Biochemical and Food Biotechnology, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa; E-Mails: (C.S.); (A.O.); (K.D.); (C.P.)
| | - Andries Olivier
- UNESCO MIRCEN: Microbial, Biochemical and Food Biotechnology, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa; E-Mails: (C.S.); (A.O.); (K.D.); (C.P.)
| | - Khumisho Dithebe
- UNESCO MIRCEN: Microbial, Biochemical and Food Biotechnology, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa; E-Mails: (C.S.); (A.O.); (K.D.); (C.P.)
| | - Carolina Pohl
- UNESCO MIRCEN: Microbial, Biochemical and Food Biotechnology, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa; E-Mails: (C.S.); (A.O.); (K.D.); (C.P.)
| | - Pieter van Wyk
- Centre for Microscopy, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa; E-Mail:
| | - Hendrik Swart
- Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa; E-Mails: (H.S.); (E.C.)
| | - Elizabeth Coetsee
- Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa; E-Mails: (H.S.); (E.C.)
| | - Lodewyk Kock
- UNESCO MIRCEN: Microbial, Biochemical and Food Biotechnology, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa; E-Mails: (C.S.); (A.O.); (K.D.); (C.P.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +27-51-401-2249; Fax: +27-51-401-9376
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84
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Jennings P, Limonciel A, Felice L, Leonard MO. An overview of transcriptional regulation in response to toxicological insult. Arch Toxicol 2012; 87:49-72. [DOI: 10.1007/s00204-012-0919-y] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Accepted: 07/30/2012] [Indexed: 12/30/2022]
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85
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Raoux M, Azorin N, Colomban C, Rivoire S, Merrot T, Delmas P, Crest M. Chemicals inducing acute irritant contact dermatitis mobilize intracellular calcium in human keratinocytes. Toxicol In Vitro 2012; 27:402-8. [PMID: 22906572 DOI: 10.1016/j.tiv.2012.08.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Revised: 04/16/2012] [Accepted: 08/02/2012] [Indexed: 01/30/2023]
Abstract
Intracellular Ca(2+) increase is a common feature of multiple cellular pathways associated with receptor and channel activation, mediator secretion and gene regulation. We investigated the possibility of using this Ca(2+) signal as a biomarker for a reaction to chemical irritants of normal human keratinocytes (NHK) in submerged primary cell culture. We tested 14 referenced chemical compounds classified as strong (seven), weak (four) or non- (three) irritants in acute irritant contact dermatitis. We found that the strong irritant compounds tested at 20-40 mM induced an intracellular Ca(2+) increase measurable by spectrofluorimetry in an automated test. Weak and non-irritant compounds however did not increase intracellular Ca(2+) concentration. We further investigated the mechanisms by which the amine heptylamine, classified as a R34 corrosive compound, increases intracellular Ca(2+). Heptylamine (20mM) induced an ATP release that persisted in the absence of intra- and extra-cellular Ca(2+). In addition, we found that this ATP activates NHK purinergic receptors that subsequently cause the increase in intracellular Ca(2+) from sarcoplasmic reticular stores. We conclude that measuring the intracellular Ca(2+) concentration in NHK is a suitable and easy way of determining any potential reaction to soluble chemical compounds.
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Affiliation(s)
- Matthieu Raoux
- Université de la Méditerranée, Centre National de la Recherche Scientifique UMR 6231, Marseille, France
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86
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Hroudová J, Fišar Z. In vitro inhibition of mitochondrial respiratory rate by antidepressants. Toxicol Lett 2012; 213:345-52. [PMID: 22842584 DOI: 10.1016/j.toxlet.2012.07.017] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 07/04/2012] [Accepted: 07/19/2012] [Indexed: 12/11/2022]
Abstract
Mitochondria represent a possible drug target with unexplored therapeutic and toxicological potential. The possibility was suggested that antidepressants, mood stabilizers and other drugs may show some therapeutic and/or toxic effects through their action on mitochondrial functions. There are no sufficient data about the effect of these drugs on mitochondrial respiration in the brain. We investigated the in vitro effects of amitriptyline, fluoxetine, tianeptine, ketamine, lithium, valproate, olanzapine, chlorpromazine and propranolol on mitochondrial respiration in crude mitochondrial fractions of pig brains. Respiration was energized using substrates of complex I or complex II and dose dependent drug-induced changes in mitochondrial respiratory rate were measured by high-resolution respirometry. Antidepressants, but not mood stabilizers, ketamine and propranolol were found to inhibit mitochondrial respiratory rate. The effective dose of antidepressants reaching half the maximal respiratory rate was in the range of 0.07-0.46 mmol/L. Partial inhibition was found for all inhibitors. Differences between individual drugs with similar physicochemical properties indicate selectivity of drug-induced changes in mitochondrial respiratory rate. Our findings suggest that mood stabilizers do not interfere with brain mitochondrial respiration, whereas direct mitochondrial targeting is involved in mechanisms of action of pharmacologically different antidepressants.
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Affiliation(s)
- Jana Hroudová
- Department of Psychiatry, Charles University in Prague and General University Hospital in Prague, Ke Karlovu 11, 120 00 Prague, Czech Republic
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87
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Bourdineaud JP, Rossignol R, Brèthes D. Zebrafish: a model animal for analyzing the impact of environmental pollutants on muscle and brain mitochondrial bioenergetics. Int J Biochem Cell Biol 2012; 45:16-22. [PMID: 22842533 DOI: 10.1016/j.biocel.2012.07.021] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2012] [Accepted: 07/18/2012] [Indexed: 12/26/2022]
Abstract
Mercury, anthropogenic release of uranium (U), and nanoparticles constitute hazardous environmental pollutants able to accumulate along the aquatic food chain with severe risk for animal and human health. The impact of such pollutants on living organisms has been up to now approached by classical toxicology in which huge doses of toxic compounds, environmentally irrelevant, are displayed through routes that never occur in the lifespan of organisms (for instance injecting a bolus of mercury to an animal although the main route is through prey and fish eating). We wanted to address the effect of such pollutants on the muscle and brain mitochondrial bioenergetics under realistic conditions, at unprecedented low doses, using an aquatic model animal, the zebrafish Danio rerio. We developed an original method to measure brain mitochondrial respiration: a single brain was put in 1.5 mL conical tube containing a respiratory buffer. Brains were gently homogenized by 13 strokes with a conical plastic pestle, and the homogenates were immediately used for respiration measurements. Skinned muscle fibers were prepared by saponin permeabilization. Zebrafish were contaminated with food containing 13 μg of methylmercury (MeHg)/g, an environmentally relevant dose. In permeabilized muscle fibers, we observed a strong inhibition of both state 3 mitochondrial respiration and cytochrome c oxidase activity after 49 days of MeHg exposure. We measured a dramatic decrease in the rate of ATP release by skinned muscle fibers. Contrarily to muscles, brain mitochondrial respiration was not modified by MeHg exposure although brain accumulated twice as much MeHg than muscles. When zebrafish were exposed to 30 μg/L of waterborne U, the basal mitochondrial respiratory control ratio was decreased in muscles after 28 days of exposure. This was due to an increase of the inner mitochondrial membrane permeability. The impact of a daily ration of food containing gold nanoparticles of two sizes (12 and 50 nm) was investigated at a very low dose for 60 days (40 ng gold/fish/day). Mitochondrial dysfunctions appeared in brain and muscle for both tested sizes. In conclusion, at low environmental doses, dietary or waterborne heavy metals impinged on zebrafish tissue mitochondrial respiration. Due to its incredible simplicity avoiding tedious and time-consuming mitochondria isolation, our one-pot method allowing brain respiratory analysis should give colleagues the incentive to use zebrafish brain as a model in bioenergetics. This article is part of a Directed Issue entitled: Bioenergetic dysfunction, adaptation and therapy.
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Affiliation(s)
- Jean-Paul Bourdineaud
- University of Bordeaux, CNRS, UMR 5805, Station marine d'Arcachon, Place du Dr Peyneau, 33120 Arcachon, France.
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88
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Bantel H, Schulze-Osthoff K. Mechanisms of cell death in acute liver failure. Front Physiol 2012; 3:79. [PMID: 22485095 PMCID: PMC3317271 DOI: 10.3389/fphys.2012.00079] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Accepted: 03/16/2012] [Indexed: 12/27/2022] Open
Abstract
Acute liver failure (ALF) can be the consequence of various etiologies, that might vary between different geographic regions. Most frequent are intoxications with acetaminophen, viral hepatitis, or liver damage of unknown origin. ALF occurs when the extent of hepatocyte death exceeds the regenerative capacity of the liver. The mode of liver cell death that is predominantly induced in ALF, i.e., apoptosis or necrosis, is still controversial and presumably determined by the etiology, duration, and magnitude of liver injury. Severe liver damage involves oxidative stress and depletion of ATP resulting in necrosis. In contrast, maintenance of ATP stores is required for the execution of apoptosis. Recent data suggest that necrosis resulting from severe liver damage is associated with poor outcome of ALF patients. Discrimination between apoptosis and necrosis might be therefore useful for the identification of ALF patients requiring liver transplantation. Identification of the molecular cell death mechanisms remains an important issue not only for early prediction of ALF outcome, but also for therapeutic interventions. In view of the pleiotropic functions of critical mediators of cell death and tissue regeneration, a particular challenge will be to reduce hepatocellular death without inhibiting the regenerative capacity of the liver. Here, we review the molecular mechanisms of hepatocyte injury and the pathways leading to apoptosis and necrosis, which might represent potential diagnostic and therapeutic targets in ALF.
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Affiliation(s)
- Heike Bantel
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School Hannover, Germany
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89
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Sakamuru S, Li X, Attene-Ramos MS, Huang R, Lu J, Shou L, Shen M, Tice RR, Austin CP, Xia M. Application of a homogenous membrane potential assay to assess mitochondrial function. Physiol Genomics 2012; 44:495-503. [PMID: 22433785 DOI: 10.1152/physiolgenomics.00161.2011] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Decreases in mitochondrial membrane potential (MMP) have been associated with mitochondrial dysfunction that could lead to cell death. The MMP is generated by an electrochemical gradient via the mitochondrial electron transport chain coupled to a series of redox reactions. Measuring the MMP in living cells is commonly used to assess the effect of chemicals on mitochondrial function; decreases in MMP can be detected using lipophilic cationic fluorescent dyes. To identify an optimal dye for use in a high-throughput screening (HTS) format, we compared the ability of mitochondrial membrane potential sensor (Mito-MPS), 5,5',6,6'-tetrachloro-1,1',3,3' tetraethylbenzimidazolylcarbocyanine iodide, rhodamine 123, and tetramethylrhodamine to quantify a decrease in MMP in chemically exposed HepG2 cells cultured in 1,536-well plates. Under the conditions used, the optimal dye for this purpose is Mito-MPS. Next, we developed and optimized a homogenous cell-based Mito-MPS assay for use in 1,536-well plate format and demonstrated the utility of this assay by screening 1,280 compounds in the library of pharmacologically active compounds in HepG2 cells using a quantitative high-throughput screening platform. From the screening, we identified 14 compounds that disrupted the MMP, with half-maximal potencies ranging from 0.15 to 18 μM; among these, compound clusters that contained tyrphostin and 3'-substituted indolone analogs exhibited a structure-activity relationship. Our results demonstrate that this homogenous cell-based Mito-MPS assay can be used to evaluate the ability of large numbers of chemicals to decrease mitochondrial function.
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Affiliation(s)
- Srilatha Sakamuru
- NIH Chemical Genomics Center, National Institutes of Health, Bethesda, Maryland 20892-3370, USA
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90
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Miles MV, Miles L, Horn PS, DeGrauw TJ. Enzyme inducing antiepileptic drugs are associated with mitochondrial proliferation and increased cytochrome c oxidase activity in muscle of children with epilepsy. Epilepsy Res 2012; 98:76-87. [DOI: 10.1016/j.eplepsyres.2011.08.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 08/19/2011] [Accepted: 08/27/2011] [Indexed: 10/17/2022]
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91
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Braun FK, Al-Yacoub N, Plötz M, Möbs M, Sterry W, Eberle J. Nonsteroidal anti-inflammatory drugs induce apoptosis in cutaneous T-cell lymphoma cells and enhance their sensitivity for TNF-related apoptosis-inducing ligand. J Invest Dermatol 2011; 132:429-39. [PMID: 22011910 DOI: 10.1038/jid.2011.316] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Cutaneous T-cell lymphomas (CTCL) form a heterogeneous group of non-Hodgkin's lymphomas of the skin. In previous studies, we had characterized CTCL cells as resistant to the death ligand tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which correlated to pronounced expression of the caspase-8/-10 inhibitor c-FLIP. For identification of proapoptotic strategies in CTCL cells and for overcoming their death ligand resistance, we investigated the effects of nonsteroidal anti-inflammatory drugs (NSAIDs) such as acetylsalicylic acid, sodium salicylate, and diclofenac (DF). These drugs strongly enhanced apoptosis, as well as decreased CTCL cell proliferation and vitality, and DF furthermore sensitized for TRAIL-induced apoptosis. Full activation of the caspase cascade (caspase-3, -8, -9) and decreased mitochondrial membrane potential were characteristic for NSAID treatment, whereas cytochrome c release was seen only for DF. Downregulation of Mcl-1 and enhanced surface expression of TRAIL were seen in response to NSAIDs. Most characteristic for apoptosis induction was the downregulation of c-FLIP. In agreement with the critical role of c-FLIP for apoptosis deficiency of CTCL cells, its overexpression decreased NSAID-mediated apoptosis and its downregulation by small hairpin RNA-enhanced apoptosis. The study provides a rationale for the use of NSAIDs as a new therapeutic option for CTCL patients. Supporting this concept, ex vivo lymphoma cells of CTCL patients also revealed significant sensitivity for NSAID treatment.
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Affiliation(s)
- Frank K Braun
- Department of Dermatology and Allergy, Skin Cancer Center Charité (HTCC), Charité-University Medical Center Berlin, Berlin, Germany
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92
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Predicting in vivo safety characteristics using physiochemical properties and in vitro assays. Future Med Chem 2011; 3:1503-11. [DOI: 10.4155/fmc.11.89] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
There is increasing pressure on the pharmaceutical industry to deliver safer and more effective medicines while constraining research and development costs. In order to meet these demands, the industry is looking for basic design principles in terms of physicochemical properties as well as the use of higher throughput in vitro assays to select and evaluate new molecular entities for further development. Recent advances in understanding the relationships between a chemical’s properties and its propensity for adverse events, as well as the development of new in vitro screening technologies, have enhanced our ability to potentially select molecules more likely to succeed in becoming drugs. However, these approaches are still limited by the availability of data and our lack of understanding of the mechanisms by which compounds can cause toxicity.
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Kock JLF, Swart CW, Pohl CH. The anti-mitochondrial antifungal assay for the discovery and development of new drugs. Expert Opin Drug Discov 2011; 6:671-81. [PMID: 22646155 DOI: 10.1517/17460441.2011.575358] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
INTRODUCTION New targets and drugs are constantly searched for to effectively combat fungal infections and diseases such as cancer. Mitochondria, as the main powerhouses of eukaryotic cells, must be regarded as important targets for the development of new therapies. This has lead to the development of a fungal assay that shows potential in the selection of new antifungal and anticancer drugs as well as the identification of compounds that are toxic to human mitochondria. AREAS COVERED In this review the authors discuss the development of a potential method of drug discovery that targets mitochondrial function. The authors cover the application of new nanotechnology as well as fungal systematic research where the link between fungal fruiting structures, cell growth, increased mitochondrial activity and susceptibility to a variety of anti-mitochondrial drugs is assessed. EXPERT OPINION This assay shows potential to select anti-mitochondrial drugs as a first screen. This should be followed up by more specific in vitro and in vivo tests to pinpoint the type of anti-mitochondrial activity exerted by these drugs, if any. This is because the possibility exists that compounds regarded as anti-mitochondrial may not inhibit mitochondrial function but other fruiting structure developmental stages and therefore yield false positives. To enhance our knowledge on how these drugs act at the structural level, the authors recommend Nano Scanning Auger Microscopy as the tool of choice.
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Affiliation(s)
- J Lodewyk F Kock
- University of the Free State, Department of Microbial , Biochemical and Food Biotechnology, Bloemfontein , South Africa +27514012249 ; +27514019376 ;
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94
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Nadanaciva S, Will Y. Current concepts in drug-induced mitochondrial toxicity. ACTA ACUST UNITED AC 2011; Chapter 2:Unit 2.15. [PMID: 20941696 DOI: 10.1002/0471140856.tx0215s40] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mitochondria generate most of the cell's ATP and play key roles in fatty acid oxidation, steroid synthesis, heme synthesis, thermogenesis, calcium homeostasis, and apoptosis. With the development of new methods to study mitochondrial function, it is becoming clear that drug-induced mitochondrial dysfunction is one of the causes of drug toxicity. Mitochondria can be impaired by drugs in a variety of ways. These include inhibition of oxidative phosphorylation, uncoupling of electron transport from ATP synthesis, irreversible opening of the mitochondrial permeability transition pore, inhibition of transporters within the mitochondrial inner membrane, increased oxidative stress, inhibition of the citric acid cycle, inhibition of fatty acid oxidation, and impairment of either mtDNA replication or mtDNA-encoded protein synthesis. This unit provides an overview on the physiological roles of mitochondria and the mechanisms by which they can be adversely affected by drugs.
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95
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Dykens JA, Will Y. Biomarkers of in Vitro Drug‐Induced Mitochondrial Dysfunction. Biomarkers 2010. [DOI: 10.1002/9780470918562.ch16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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96
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McKim JM. Building a tiered approach to in vitro predictive toxicity screening: a focus on assays with in vivo relevance. Comb Chem High Throughput Screen 2010; 13:188-206. [PMID: 20053163 PMCID: PMC2908937 DOI: 10.2174/138620710790596736] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Accepted: 05/05/2009] [Indexed: 12/23/2022]
Abstract
One of the greatest challenges facing the pharmaceutical industry today is the failure of promising new drug candidates due to unanticipated adverse effects discovered during preclinical animal safety studies and clinical trials. Late stage attrition increases the time required to bring a new drug to market, inflates development costs, and represents a major source of inefficiency in the drug discovery/development process. It is generally recognized that early evaluation of new drug candidates is necessary to improve the process. Building in vitro data sets that can accurately predict adverse effects in vivo would allow compounds with high risk profiles to be deprioritized, while those that possess the requisite drug attributes and a lower risk profile are brought forward. In vitro cytotoxicity assays have been used for decades as a tool to understand hypotheses driven questions regarding mechanisms of toxicity. However, when used in a prospective manner, they have not been highly predictive of in vivo toxicity. Therefore, the issue may not be how to collect in vitro toxicity data, but rather how to translate in vitro toxicity data into meaningful in vivo effects. This review will focus on the development of an in vitro toxicity screening strategy that is based on a tiered approach to data collection combined with data interpretation.
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Affiliation(s)
- James M McKim
- CeeTox Inc., 4717 Campus Dr., Kalamazoo, MI 49008, USA.
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97
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Berger I, Segal I, Shmueli D, Saada A. The effect of antiepileptic drugs on mitochondrial activity: a pilot study. J Child Neurol 2010; 25:541-5. [PMID: 20413803 DOI: 10.1177/0883073809352888] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Mitochondria are probably a target in antiepileptic drug-induced hepatotoxicity accompanied by oxidative stress. Most studies discuss valproic acid. The information regarding other antiepileptic drugs is scarce. Most studies used in vitro methods and animal models. In this study, the authors have investigated the effect of antiepileptic drugs, other than valproic acid, on the oxidative phosphorylation process in children, by measuring mitochondrial adenosine triphosphate (ATP) production and the enzymatic activities of respiratory chain complexes II-IV in peripheral white blood cells. The results demonstrate that several antiepileptic drugs can affect the mitochondrial oxidative phosphorylation. The authors have concluded that the effect of antiepileptic drugs on the mitochondria is not limited only to valproic acid, but can affect different mitochondrial pathways and can be performed in humans by relatively simple methods, using small samples of peripheral white blood cells.
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Affiliation(s)
- Itai Berger
- The Neuro-Pediatric Unit, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
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98
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Sivitz WI, Yorek MA. Mitochondrial dysfunction in diabetes: from molecular mechanisms to functional significance and therapeutic opportunities. Antioxid Redox Signal 2010; 12:537-77. [PMID: 19650713 PMCID: PMC2824521 DOI: 10.1089/ars.2009.2531] [Citation(s) in RCA: 507] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Given their essential function in aerobic metabolism, mitochondria are intuitively of interest in regard to the pathophysiology of diabetes. Qualitative, quantitative, and functional perturbations in mitochondria have been identified and affect the cause and complications of diabetes. Moreover, as a consequence of fuel oxidation, mitochondria generate considerable reactive oxygen species (ROS). Evidence is accumulating that these radicals per se are important in the pathophysiology of diabetes and its complications. In this review, we first present basic concepts underlying mitochondrial physiology. We then address mitochondrial function and ROS as related to diabetes. We consider different forms of diabetes and address both insulin secretion and insulin sensitivity. We also address the role of mitochondrial uncoupling and coenzyme Q. Finally, we address the potential for targeting mitochondria in the therapy of diabetes.
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Affiliation(s)
- William I Sivitz
- Department of Internal Medicine, Division of Endocrinology and Metabolism, Iowa City Veterans Affairs Medical Center and University of Iowa, Iowa City, Iowa, USA.
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Marusich MF, Murray J, Xie J, Capaldi RA. Novel antibody-based strategies for the rapid diagnosis of mitochondrial disease and dysfunction. Int J Biochem Cell Biol 2009; 41:2081-8. [PMID: 19460456 DOI: 10.1016/j.biocel.2009.05.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2009] [Revised: 05/10/2009] [Accepted: 05/11/2009] [Indexed: 12/23/2022]
Abstract
We are developing rapid immunoassays to measure the protein levels, enzymatic activities and post-translational modifications of mitochondrial proteins. These assays can be arrayed in multi-analyte panels for biomarker discovery and they can also be used individually at point of care where the level or activity of a small number proteins or even a single protein is highly informative. For example, we have characterized OXPHOS deficits associated with lipoatrophy, an adverse metabolic side-effect of anti-retroviral therapy, and have shown that OXPHOS deficits observed in vitro are also exhibited not only in clinically affected tissue (peripheral fat) but also in more easily accessible tissue (peripheral blood mononucleated cells). Similarly, we have shown that a small set of assays can be used to identify almost all patients with genetic deficits in OXPHOS complexes I or IV, the most common cause of inherited mitochondrial disease. Finally, we recently reported that Friedreich's Ataxia (FA) patients and carriers can be identified on the basis of a simple dipstick test to measure levels of a single protein, frataxin, an iron regulatory protein whose disrupted expression is the proximal cause of neurodegeneration in FA. Because each of these tests can be performed in an extremely simple, rapid dipstick format using non-invasive samples such as cheek swabs and fingerprick blood, they have potential for use as point of care diagnostics for mitochondrial disease and as front-line screening tools to help guide drug therapies and minimize adverse off-target drug effects.
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Pereira SP, Pereira GC, Moreno AJ, Oliveira PJ. Can Drug Safety be Predicted and Animal Experiments Reduced by Using Isolated Mitochondrial Fractions? Altern Lab Anim 2009; 37:355-65. [DOI: 10.1177/026119290903700406] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Mitochondrial toxicity has resulted in the withdrawal of several drugs from the market. One particular example is nefazodone, an anti-depressant withdrawn in the USA due to hepatoxicity caused by drug-induced mitochondrial dysfunction. Drug development and safety testing can involve the use of large numbers of laboratory animals, which, without a decisive pre-screening for mitochondrial toxicity, are often unable to pre-empt higher mortality rates in some patient groups. The use of isolated mitochondria as a screening tool for drug safety can decrease the number of laboratory animals used in pre-clinical studies, thus improving animal welfare and healthcare outcomes and costs. Novel techniques involving high-throughput methods can be used to investigate whether a molecule is a mitochondrial toxicant. Moreover, these screens are mechanistically-based, since the effects of the drug on oxidative phosphorylation, calcium homeostasis and mitochondrial genetics can be assessed. This review is intended to demonstrate that isolated mitochondrial fractions are suitable for predicting drug and general chemical safety in toxicological screenings, thus contributing to the refinement and reduction of animal use in laboratory research.
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Affiliation(s)
- Susana P. Pereira
- Center for Neuroscience and Cell Biology, Department of Zoology, University of Coimbra, Portugal
| | - Gonçalo C. Pereira
- Center for Neuroscience and Cell Biology, Department of Zoology, University of Coimbra, Portugal
| | - António J. Moreno
- Institute of Marine Research (IMAR), Department of Zoology, University of Coimbra, Portugal
| | - Paulo J. Oliveira
- Center for Neuroscience and Cell Biology, Department of Zoology, University of Coimbra, Portugal
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