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Narchi H, Thachillath P, Souid AK. Forebrain cellular bioenergetics in neonatal mice. J Neonatal Perinatal Med 2018; 11:79-86. [PMID: 29689747 DOI: 10.3233/npm-181737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Hypoglycemia occurs frequently in the neonate and may result in neurologic dysfunction. Its impact on the kinetics of cellular respiration and bioenergetics in the neonatal brain remains to be explored. AIMS Develop murine model to investigate the effects of hypoglycemia on neonatal brain bioenergetics. STUDY DESIGN Forebrain fragments were excised from euthanized BALB/c pups aged <24 hours to 14 days. We measured cellular respiration (μM O2 min-1.mg-1) in phosphate-buffered saline with and without glucose, using phosphorescence oxygen analyzer, as well as cellular adenosine triphosphate (ATP, nmol.mg-1) using the luciferin-luciferase system. RESULTS In the presence of glucose, although cellular respiration was 11% lower in pups ≤3 days compared to those 3- 14 days old (0.48 vs. 0.54), that difference was not statistically significant (p = 0.14). Respiration driven by endogenous metabolic fuels (without added glucose) was 16% lower in pups ≤3 days compared to those 3- 14 days (0.35 vs. 0.42, p = 0.03), confirming their increased dependency on exogenous glucose. Although cellular ATP was similar between the two age groups (14.9 vs. 11.2, p = 0.32), the ATP content was more severely depleted without added glucose in the younger pups, especially in the presence of the cytochrome c oxidase inhibitor cyanide. The first-order rate constant of cellular ATP decay (hydrolysis) was 44% lower in 2-day-old pups compared to 14-day-old mice (0.43 vs. 0.77 min-1, p = 0.03). CONCLUSIONS Forebrain cellular respiration and ATP consumption are lower in young pups than older mice. In the absence of glucose, the support for these processes is reduced in young pups, explaining their brain hypersensitivity to hypoglycemia.
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Affiliation(s)
- Hassib Narchi
- Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, United Arab Emirates
| | - Pramathan Thachillath
- Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, United Arab Emirates
| | - Abdul-Kader Souid
- Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, United Arab Emirates
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Alsamri MT, Al-Hammadi S, Islam B, Souid AK. Zoledronic acid and bone cellular respiration. J Bone Miner Metab 2018; 36:392-398. [PMID: 28766136 DOI: 10.1007/s00774-017-0850-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 06/06/2017] [Indexed: 11/30/2022]
Abstract
Phosphorescence O2 analyzer was used to measure calvarial bone cellular respiration (cellular mitochondrial O2 consumption) in Taylor Outbred mice in the presence and absence of zoledronic acid. This potent bisphosphonate inhibits osteoclast-mediated calcium resorption, and its effects on bone respiration have not been previously investigated. The change of O2 concentration with time was measured in closed vials containing phosphate-buffered saline (PBS), 5 mM glucose and 5-25 mg calvarial bone fragments, and it was complex for t = 0-30 h. Cyanide (specific inhibitor of cytochrome oxidase) halted O2 consumption, confirming the oxidation occurred in the respiratory chain. Initial rate of respiration was estimated from the zero-order plots d[O2]/dt for t = 0-4 h. For untreated specimens, the rate (mean ± SD) was 2.0 ± 1.2 µM O2 h-1 mg-1 (n = 6). This value was 7-10 times lower than that of other murine organs, but similar to that reported for rat and Guinea pig calvaria (averaging, 2.7 nmol O2 h-1 mg-1). The corresponding rate in the presence of 10-100 µM zoledronic acid was 2.7 ± 0.7 µM O2 h-1 mg-1 (n = 11), p = 0.216. The first-order plots ln ([O2] t ÷ [O2] t=0) versus time for t = 0-30 h were also used to compare treated and untreated specimens. The rate (h-1 mg-1 103) for specimens incubated in PBS without glucose was 1.3 ± 0.6 (n = 3, p = 0.007), in PBS + glucose it was 10.7 ± 6.9 (n = 10), in PBS + glucose + 10 µM zoledronic acid it was 12.1 ± 6.7 (n = 10, p = 0.579), in PBS + glucose + 20 µM zoledronic acid it was 12.9 ± 3.3 (n = 9, p = 0.356), and in PBS + glucose + 100 µM zoledronic acid it was 13.7 ± 7.7 (n = 9, p = 0.447). Thus, exposure to high-doses of zoledronic acid over several hours imposed a statistically insignificant increase in calvarial bone cellular respiration.
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Affiliation(s)
- Mohammed T Alsamri
- Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain, UAE
| | - Suleiman Al-Hammadi
- Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain, UAE
| | - Barira Islam
- Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain, UAE
| | - Abdul-Kader Souid
- Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain, UAE.
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Al-Shamsi M, Shahin A, Ibrahim MF, Tareq S, Souid AK, Mensah-Brown EPK. Bioenergetics of the spinal cord in experimental autoimmune encephalitis of rats. BMC Neurosci 2015; 16:37. [PMID: 26092157 PMCID: PMC4474435 DOI: 10.1186/s12868-015-0175-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 06/10/2015] [Indexed: 12/16/2022] Open
Abstract
Background Mitochondrial dysregulation is important in axonal damage and demyelination in multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE). There is however, no evidence in the literature of any study that has examined cellular bioenergetics of the central nervous system (CNS) during the early development and clinical course of EAE. EAE, a rodent model of relapsing/remitting MS, is a CD4+ T cell-mediated disease of the CNS. We hypothesize that CNS bioenergetics might predict prognosis, and that preserved bioenergetics might underlie the remission from disease. The study aims therefore, to determine whether the clinical history of EAE is influenced by cellular respiration of the CNS in susceptible Dark Agouti (DA) and resistant Albino Oxford (AO) rats. Methods Experimental autoimmune encephalomyelitis was induced by myelin basic protein in complete Freud Adjuvant in the footpads of DA and AO rats. A phosphorescence analyzer that determines cellular respiration was used to monitor oxygen consumption and ATP concentration was measured using the Enliten ATP assay system. Disease pathology was demonstrated by H&E and Luxol fast blue staining of sections of the lumbar regions of the spinal cord. Mitochondrial size in relation to axonal size was determined by electron microscopy. Apoptosis was studied by HPLC measurement of intracellular caspase-3 activity and caspase immunohistochemistry. Role and source of caspase 1 was studied by double immunofluorescence with antibodies for caspase-1, microglia (anti-Iba1) and astrocytes (anti-GFAP). Results The cellular respiration of the CNS did not vary between diseased and normal rats. We also demonstrate here, that at the peak of disease, inflammation as shown by caspase-1, produced by activated microglia and infiltrating cells, was significant in susceptible DA rats. The mitochondrial:axonal size ratio did not vary in the different groups although mitochondria were smaller in spinal cords of diseased DA rats. Demyelination, observed only in areas of mononuclear infiltration of the spinal cord of diseased DA rats, was demonstrated by light microscopy and electron microscopy. Conclusion We conclude that EAE at this early stage does not significantly affect CNS cellular respiration and this might underlie the reason for the recovery of diseased rats.
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Affiliation(s)
- Mariam Al-Shamsi
- Department of Medical Microbiology and Immunology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE.
| | - Allen Shahin
- Department of Medical Microbiology and Immunology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE.
| | - Marwa F Ibrahim
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE.
| | - Saeed Tareq
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE.
| | - Abdul-Kader Souid
- Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE.
| | - Eric P K Mensah-Brown
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE.
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Giorello FM, Feijoo M, D’Elía G, Valdez L, Opazo JC, Varas V, Naya DE, Lessa EP. Characterization of the kidney transcriptome of the South American olive mouse Abrothrix olivacea. BMC Genomics 2014; 15:446. [PMID: 24909751 PMCID: PMC4189146 DOI: 10.1186/1471-2164-15-446] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 05/27/2014] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND The olive mouse Abrothrix olivacea is a cricetid rodent of the subfamily Sigmodontinae that inhabits a wide range of contrasting environments in southern South America, from aridlands to temperate rainforests. Along its distribution, it presents different geographic forms that make the olive mouse a good focal case for the study of geographical variation in response to environmental variation. We chose to characterize the kidney transcriptome because this organ has been shown to be associated with multiple physiological processes, including water reabsorption. RESULTS Transcriptomes of thirteen kidneys from individuals from Argentina and Chile were sequenced using Illumina technology in order to obtain a kidney reference transcriptome. After combining the reads produced for each sample, we explored three assembly strategies to obtain the best reconstruction of transcripts, TrinityNorm and DigiNorm, which include its own normalization algorithms for redundant reads removal, and Multireads, which simply consist on the assembly of the joined reads. We found that Multireads strategy produces a less fragmented assembly than normalization algorithms but recovers fewer number of genes. In general, about 15000 genes were annotated, of which almost half had at least one coding sequence reconstructed at 99% of its length. We also built a list of highly expressed genes, of which several are involved in water conservation under laboratory conditions using mouse models. CONCLUSION Based on our assembly results, Trinity's in silico normalization is the best algorithm in terms of cost-benefit returns; however, our results also indicate that normalization should be avoided if complete or nearly complete coding sequences of genes are desired. Given that this work is the first to characterize the transcriptome of any member of Sigmodontinae, a subfamily of cricetid rodents with about 400 living species, it will provide valuable resources for future ecological and evolutionary genomic analyses.
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Affiliation(s)
- Facundo M Giorello
- />Departamento de Ecología y Evolución, Facultad de
Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Matias Feijoo
- />Departamento de Ecología y Evolución, Facultad de
Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Guillermo D’Elía
- />Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile
| | - Lourdes Valdez
- />Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile
| | - Juan C Opazo
- />Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile
| | - Valeria Varas
- />Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile
| | - Daniel E Naya
- />Departamento de Ecología y Evolución, Facultad de
Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Enrique P Lessa
- />Departamento de Ecología y Evolución, Facultad de
Ciencias, Universidad de la República, Montevideo, Uruguay
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Aburawi EH, Souid AK. Inhibition of murine cardiomyocyte respiration by amine local anesthetics. Eur J Drug Metab Pharmacokinet 2013; 39:293-9. [DOI: 10.1007/s13318-013-0159-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Accepted: 11/06/2013] [Indexed: 11/29/2022]
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Alsamri MT, Pramathan T, Souid AK. In vitro study on the pulmonary cytotoxicity of amiodarone. Toxicol Mech Methods 2013; 23:610-6. [PMID: 23738705 DOI: 10.3109/15376516.2013.812170] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CONTEXT Amiodarone (an iodinated benzofuran) is a Class III antiarrhythmic drug that produces significant pulmonary disease. Proposed mechanisms of this cytotoxicity include necrosis, apoptosis, mitochondrial dysfunction and glutathione depletion. OBJECTIVE This study was designed primarily to explore whether amiodarone impairs lung tissue cellular bioenergetics in BALB/c and Taylor Outbred mice. MATERIALS AND METHODS Cellular respiration (mitochondrial O2 consumption), ATP, caspase activity and glutathione were measured in lung fragments incubated in vitro with 22 µM amiodarone for several hours. RESULTS Without amiodarone, lung tissue cellular mitochondrial O2 consumption decayed exponentially with time, showing two distinct phases sharply separated at t ≥ 150 min. The rate of cellular respiration was 6-10-fold higher in the late phase compared to the early phase (p<0.0001). Lung tissue ATP also decayed exponentially with time, suggesting "uncoupling oxidative phosphorylation" was the responsible mechanism (low cellular ATP with high mitochondrial O2 consumption, resulting in rapid depletion of cellular metabolic fuels). Although intracellular caspase activity increased exponentially with time, the uncoupling was not prevented by the pancaspase inhibitor zVAD-fmk (N-benzyloxycarbonyl-val-ala-asp (O-methyl)-fluoromethylketone). The same profiles were noted in the presence of amiodarone; but cellular ATP decayed 50% faster. Cellular glutathione for untreated tissue was 560 ± 287 pmol mg(-1) (n=12) and for treated tissue was 490 ± 226 pmol mg(-1) (n=12, p=0.5106). CONCLUSION Uncoupling oxidative phosphorylation was demonstrated in untreated mouse lung tissues. Amiodarone lowered cellular ATP. Further studies are needed to explore the susceptibility of the lung to these deleterious insults and their relevance to human diseases.
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Affiliation(s)
- Mohammed T Alsamri
- Department of Pediatrics, United Arab Emirates University , Al Ain , UAE
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Alsuwaidi AR, Almarzooqi S, Albawardi A, Benedict S, Kochiyil J, Mustafa F, Hartwig SM, Varga SM, Souid AK. Cellular bioenergetics, caspase activity and glutathione in murine lungs infected with influenza A virus. Virology 2013; 446:180-8. [PMID: 24074580 DOI: 10.1016/j.virol.2013.07.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 06/27/2013] [Accepted: 07/25/2013] [Indexed: 01/30/2023]
Abstract
Inhibition of cellular respiration, oxidation of glutathione and induction of apoptosis have been reported in epithelial cells infected in vitro with influenza A virus (IAV). Here, the same biomarkers were investigated in vivo by assessing the lungs of BALB/c mice infected with IAV. Cellular respiration declined on day 3 and recovered on day 7 post-infection. For days 3-5, the rate (mean±SD) of respiration (µMO2min(-1)mg(-1)) in uninfected lungs was 0.103±0.021 (n=4) and in infected lungs was 0.076±0.025 (n=4, p=0.026). Relative cellular ATP (infected/uninfected) was 4.7 on day 2 and 1.07 on day 7. Intracellular caspase activity peaked on day 7. Cellular glutathione decreased by ≥10% on days 3-7. Lung pathology was prominent on day 3 and caspase-3 labeling was prominent on day 5. IAV infection was associated with suppression of cellular respiration, diminished glutathione, and induction of apoptosis. These functional biomarkers were associated with structural changes noted in infected mice.
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Affiliation(s)
- Ahmed R Alsuwaidi
- Departments of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain, United Arab Emirates.
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Al Samri MT, Silva R, Almarzooqi S, Albawardi A, Othman ARD, Al Hanjeri RSMS, Al Dawaar SK, Tariq S, Souid AK, Asefa T. Lung toxicities of core-shell nanoparticles composed of carbon, cobalt, and silica. Int J Nanomedicine 2013; 8:1223-44. [PMID: 23658487 PMCID: PMC3610446 DOI: 10.2147/ijn.s39649] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
We present here comparative assessments of murine lung toxicity (biocompatibility) after in vitro and in vivo exposures to carbon (C–SiO2-etched), carbon–silica (C–SiO2), carbon–cobalt–silica (C–Co–SiO2), and carbon–cobalt oxide–silica (C–Co3O4–SiO2) nanoparticles. These nanoparticles have potential applications in clinical medicine and bioimaging, and thus their possible adverse events require thorough investigation. The primary aim of this work was to explore whether the nanoparticles are biocompatible with pneumatocyte bioenergetics (cellular respiration and adenosine triphosphate content). Other objectives included assessments of caspase activity, lung structure, and cellular organelles. Pneumatocyte bioenergetics of murine lung remained preserved after treatment with C–SiO2-etched or C–SiO2 nanoparticles. C–SiO2-etched nanoparticles, however, increased caspase activity and altered lung structure more than C–SiO2 did. Consistent with the known mitochondrial toxicity of cobalt, both C–Co–SiO2 and C–Co3O4–SiO2 impaired lung tissue bioenergetics. C–Co–SiO2, however, increased caspase activity and altered lung structure more than C–Co3O4–SiO2. The results indicate that silica shell is essential for biocompatibility. Furthermore, cobalt oxide is the preferred phase over the zerovalent Co(0) phase to impart biocompatibility to cobalt-based nanoparticles.
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Affiliation(s)
- Mohammed T Al Samri
- Department of Pediatrics, United Arab Emirates University, Abu Dhabi, United Arab Emirates
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Alfazari AS, Al-Dabbagh B, Almarzooqi S, Albawardi A, Souid AK. Bioenergetic study of murine hepatic tissue treated in vitro with atorvastatin. BMC Pharmacol Toxicol 2013; 14:15. [PMID: 23448291 PMCID: PMC3602108 DOI: 10.1186/2050-6511-14-15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Accepted: 02/22/2013] [Indexed: 12/15/2022] Open
Abstract
Atorvastatin (a 3-hydroxy-3-methylglutaryl coenzyme-A reductase inhibitor) is a widely used cholesterol-lowering drug, which is recognized for its potential hepatotoxicity. This study investigated in vitro effects of this agent on hepatic tissue respiration, ATP content, caspase activity, urea synthesis and histology. Liver fragments from Taylor Outbred and C57Bl/6 mice were incubated at 37°C in Krebs-Henseleit buffer continuously gassed with 95% O2: 5% CO2 in the presence and absence of atorvastatin. Phosphorescence O2 analyzer that measured dissolved [O2] as a function of time was used to monitor cellular mitochondrial O2 consumption. The caspase-3 substrate N-acetyl-asp-glu-val-asp-7-amino-4-methylcoumarin was used to monitor caspase activity. The rates of hepatocyte respiration (μM O2 min-1 mg-1) in untreated samples were 0.15 ± 0.07 (n = 31). The corresponding rates for samples treated with 50 nM (therapeutic concentration), 150 nM or 1.0 μM atorvastatin for ≤13 h were 0.13 ± 0.05 (n = 19), p = 0.521. The contents of hepatocyte ATP (pmol-1 mg-1) in untreated samples were 40.3 ± 14.0 and in samples treated with 1.0 μM atorvastatin for ≤4.5 h were 48.7 ± 23.9 (p = 0.7754). The concentrations of urea (mg/dL mg-1, produced over 50 min) for untreated samples were 0.061 ± 0.020 (n = 6) and for samples treated with 1.0 μM atorvastatin for ≤6 h were 0.072 ± 0.022 (n = 6), p = 0.3866. Steadily, hepatocyte caspase activity and histology were unaffected by treatments with up to 1.0 μM atorvastatin for ≤6 h. Thus, the studied murine model showed preserved hepatocyte function and structure in the presence of high concentrations of atorvastatin.
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Affiliation(s)
- Ali S Alfazari
- Department of Internal Medicine, United Arab Emirates University, Al Ain, Abu Dhabi, United Arab Emirates.
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Alfazari AS, Al-Dabbagh B, Almarzooqi S, Albawardi A, Souid AK. A preparation of murine liver fragments for in vitro studies: liver preparation for toxicological studies. BMC Res Notes 2013; 6:70. [PMID: 23442607 PMCID: PMC3598918 DOI: 10.1186/1756-0500-6-70] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2012] [Accepted: 02/23/2013] [Indexed: 12/20/2022] Open
Abstract
Background The aim of this study was to develop liver tissue preparation suitable for investigating toxins. Hepatocyte respiration, ATP content, urea synthesis, caspase activity and morphology were measured as a function of in vitro incubation time. Mice were anesthetized by sevoflurane inhalation. Small liver fragments were then rapidly excised and incubated at 37°C in Krebs-Henseleit buffer (continuously gassed with 95% O2: 5% CO2) for up to 6 h. Phosphorescence O2 analyzer was used to determine the rate of cellular mitochondrial O2 consumption (kc, μM O2 min-1 mg-1). Cellular ATP was measured using the luciferin/luciferase system. The caspase-3 substrate N-acetyl-asp-glu-val-asp-7-amino-4-methylcoumarin (Ac-DEVD-AMC) was used to monitor intracellular caspase activity; cleaved AMC moieties (reflecting caspase activity) were separated on HPLC and detected by fluorescence. Findings Respiration was inhibited by cyanide, confirming the oxidation occurred in the respiratory chain. The values of kc (mean ± SD) for 0≤ t ≤6 h were 0.15 ± 0.02 μM O2 min-1 mg-1 (n = 18, coefficient of variation, CV = 13%), ATP content 131 ± 69 pmol mg-1 (1≤ t ≤6 h, n = 16, CV = 53%), synthesized urea 0.134 ± 0.017 mg/dL mg-1 in 50 min (0≤ t ≤6 h, n = 14, CV = 13%), and AMC peak area 62,540 ± 26,227 arbitrary units mg-1 (1≤ t ≤6 h, n = 3, CV = 42%). Hepatocyte morphology and organelles were reasonably persevered. Conclusions The described liver tissue preparation demonstrates stable hepatocyte structure, ultrastructure and biomarkers for up to 6 h, permitting in vitro studies.
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Affiliation(s)
- Ali S Alfazari
- Departments of Medicine, United Arab Emirates University, P.O. Box 15551, Al Ain, UAE
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Alsuwaidi AR, Benedict S, Kochiyil J, Mustafa F, Hartwig SM, Almarzooqi S, Albawardi A, Rizvi TA, Varga SM, Souid AK. Bioenergetics of murine lungs infected with respiratory syncytial virus. Virol J 2013; 10:22. [PMID: 23320837 PMCID: PMC3616819 DOI: 10.1186/1743-422x-10-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Accepted: 01/11/2013] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Cellular bioenergetics (cellular respiration and accompanying ATP synthesis) is a highly sensitive biomarker of tissue injury and may be altered following infection. The status of cellular mitochondrial O(2) consumption of the lung in pulmonary RSV infection is unknown. METHODS In this study, lung fragments from RSV-infected BALB/c mice were evaluated for cellular O(2) consumption, ATP content and caspase activity. The disease was induced by intranasal inoculation with the RSV strain A2 and lung specimens were analyzed on days 2-15 after inoculation. A phosphorescence O(2) analyzer that measured dissolved O(2) concentration as a function of time was used to monitor respiration. The caspase-3 substrate analogue N-acetyl-asp-glu-val-asp-7-amino-4-methylcoumarin (Ac-DEVD-AMC) was used to monitor intracellular caspases. RESULTS O(2) concentration declined linearly with time when measured in a sealed vial containing lung fragment and glucose as a respiratory substrate, revealing its zero-order kinetics. O(2) consumption was inhibited by cyanide, confirming the oxidation occurred in the respiratory chain. Cellular respiration increased by 1.6-fold (p<0.010) and ATP content increased by 3-fold in the first week of RSV infection. Both parameters returned to levels found in uninfected lungs in the second week of RSV infection. Intracellular caspase activity in infected lungs was similar to uninfected lungs throughout the course of disease. CONCLUSIONS Lung tissue bioenergetics is transiently enhanced in RSV infection. This energy burst, triggered by the virus or virus-induced inflammation, is an early biomarker of the disease and may be targeted for therapy.
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Affiliation(s)
- Ahmed R Alsuwaidi
- Departments of Pediatrics, College of Medicine and Health Sciences, UAE University, P,O, Box 17666, Al Ain, United Arab Emirates
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Al-Shamsi M, Shahin A, Mensah-Brown EPK, Souid AK. Derangements of liver tissue bioenergetics in concanavalin A-induced hepatitis. BMC Gastroenterol 2013; 13:6. [PMID: 23311450 PMCID: PMC3571906 DOI: 10.1186/1471-230x-13-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 12/13/2012] [Indexed: 12/27/2022] Open
Abstract
Background A novel in vitro system was employed to investigate liver tissue respiration (mitochondrial O2 consumption) in mice treated with concanavalin A (Con A). This study aimed to investigate hepatocyte bioenergetics in this well-studied hepatitis model. Methods C57Bl/6 and C57Bl/6 IFN-γ−/− mice were injected intravenously with 12 mg ConA/kg. Liver specimens were collected at various timepoints after injection and analyzed for cellular respiration and caspase activation. Serum was analyzed for interferon-gamma (IFN-γ) and aminotransferases. Fluorescence activated cell sorting analysis was used to determine the phenotype of infiltrating cells, and light and electron microscopy were used to monitor morphological changes. Phosphorescence analyzer that measured dissolved O2 as function of time was used to evaluate respiration. Results In sealed vials, O2 concentrations in solutions containing liver specimen and glucose declined linearly with time, confirming zero-order kinetics of hepatocyte respiration. O2 consumption was inhibited by cyanide, confirming the oxidation occurred in the respiratory chain. Enhanced liver respiration (by ≈68%, p<0.02) was noted 3 hr after ConA treatment, and occurred in conjunction with limited cellular infiltrations around the blood vessels. Diminished respiration (by ≈30%, p=0.005) was noted 12 hr after ConA treatment, and occurred in conjunction with deranged mitochondria, areas of necrosis, and prominent infiltrations with immune cells, most significantly, CD3+NKT+ cells. Increases in intracellular caspase activity and serum IFN-γ and aminotransferase levels were noted 3 hr after ConA treatment and progressed with time. The above-noted changes were less pronounced in C57Bl/6 IFN-γ−/− mice treated with ConA. Conclusions Based on these results, liver tissue bioenergetics is increased 3 hr after ConA exposure. This effect is driven by the pathogenesis of the disease, in which IFN-γ and other cytokines contribute to. Subsequent declines in liver bioenergetics appear to be a result of necrosis and active caspases targeting the mitochondria within hepatocytes.
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Affiliation(s)
- Mariam Al-Shamsi
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, United Arab Emirates
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Alsuwaidi AR, Alsamri MT, Alfazari AS, Almarzooqi S, Albawardi A, Othman AR, Pramathan T, Hartwig SM, Varga SM, Souid AK. Lung tissue bioenergetics and caspase activity in rodents. BMC Res Notes 2013; 6:12. [PMID: 23311890 PMCID: PMC3557141 DOI: 10.1186/1756-0500-6-12] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 01/10/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND This study aimed to establish a suitable in vitro system for investigating effects of respiratory pathogens and toxins on lung tissue bioenergetics (cellular respiration and ATP content) and caspase activity. Wistar rats and C57Bl/6 mice were anesthetized by sevoflurane inhalation. Lung fragments were then collected and incubated at 37°C in a continuously gassed (with 95% O2:5% CO2) Minimal Essential Medium (MEM) or Krebs-Henseleit buffer. Phosphorescence O2 analyzer that measured dissolved O2 concentration as a function of time was used to monitor the rate of cellular mitochondrial O2 consumption. Cellular ATP content was measured using the luciferin/luciferase system. The caspase-3 substrate N-acetyl-asp-glu-val-asp-7-amino-4-methylcoumarin (Ac-DEVD-AMC) was used to monitor intracellular caspase activity; cleaved AMC moieties (reflecting caspase activity) were separated on HPLC and detected by fluorescence. Lung histology and immunostaining with anti-cleaved caspase-3 antibody were also performed. RESULTS For Wistar rats, the values of kc and ATP for 0 < t ≤ 7 h (mean ± SD) were 0.15 ± 0.02 μM O2 min-1 mg-1 (n = 18, coefficient of variation, Cv = 13%) and 131 ± 69 pmol mg-1 (n = 16, Cv = 53%), respectively. The AMC peak areas remained relatively small despite a ~5-fold rise over 6 h. Good tissue preservation was evident despite time-dependent increases in apoptotic cells. Lung tissue bioenergetics, caspase activity and structure were deleterious in unoxygenated or intermittently oxygenated solutions. Incubating lung tissue in O2 depleted MEM for 30 min or anesthesia by urethane had no effect on lung bioenergetics, but produced higher caspase activity. CONCLUSIONS Lung tissue bioenergetics and structure could be maintained in vitro in oxygenated buffer for several hours and, thus, used as biomarkers for investigating respiratory pathogens or toxins.
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Affiliation(s)
- Ahmed R Alsuwaidi
- Department of Pediatrics, United Arab Emirates University, Al Ain, UAE
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Al Samri MT, Biradar AV, Alsuwaidi AR, Balhaj G, Al-Hammadi S, Shehab S, Al-Salam S, Tariq S, Pramathan T, Benedict S, Asefa T, Souid AK. In vitro biocompatibility of calcined mesoporous silica particles and fetal blood cells. Int J Nanomedicine 2012; 7:3111-21. [PMID: 22904619 PMCID: PMC3418074 DOI: 10.2147/ijn.s32711] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Indexed: 11/30/2022] Open
Abstract
Background: The biocompatibility of two forms of calcined mesoporous silica particles, labeled as MCM41-cal and SBA15-cal, with fetal blood mononuclear cells was assessed in vitro. Methods and results: Fetal mononuclear cells were isolated from umbilical cord blood and exposed to 0.5 mg/mL of MCM41-cal or SBA15-cal for several hours. Transmission electron micrographs confirmed the presence of particles in the cytosol of macrophages, neutrophils, and lymphocytes without noticeable damage to the cellular organelles. The particles (especially MCM41-cal) were in close proximity to plasma, and nuclear and mitochondrial membranes. Biocompatibility was assessed by a functional assay that measured cellular respiration, ie, mitochondrial O2 consumption. The rate of respiration (kc, in μM O2 per minute per 107 cells) for untreated cells was 0.42 ± 0.16 (n = 10), for cells treated with MCM41-cal was 0.39 ± 0.22 (n = 5, P > 0.966) and for cells treated with SBA15-cal was 0.44 ± 0.13 (n = 5, P > 0.981). Conclusion: The results show reasonable biocompatibility of MCM41-cal and SBA15-cal in fetal blood mononuclear cells. Future studies are needed to determine the potential of collecting fetal cells from a fetus or neonate, loading the cells in vitro with therapeutic MCM41-cal or SBA15-cal, and reinfusing them into the fetus or neonate.
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