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Fromm S, Cunningham CC, Dunne MR, Veale DJ, Fearon U, Wade SM. Enhanced angiogenic function in response to fibroblasts from psoriatic arthritis synovium compared to rheumatoid arthritis. Arthritis Res Ther 2019; 21:297. [PMID: 31864394 PMCID: PMC6925847 DOI: 10.1186/s13075-019-2088-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 12/12/2019] [Indexed: 12/12/2022] Open
Abstract
Introduction Angiogenesis is an early event in the pathogenesis of both psoriatic arthritis (PsA) and rheumatoid arthritis (RA); however, there are striking differences in blood vessel morphology and activation between the two arthropathies. The aim of this study was to assess if the PsA and RA joint microenvironments differentially regulate endothelial cell function. Methods PsA and RA primary synovial fibroblasts (SFC) were isolated from synovial biopsies, grown to confluence, and supernatants harvested and termed ‘conditioned media’ (CM). Human umbilical vein endothelial cells (HUVEC) were cultured with PsA SFC or RA SFC-CM (20%). HUVEC tube formation, migration, and PBMC adhesion were assessed by matrigel tube formation, wound repair, and PBMC adhesion assays. HUVEC cell surface expression of ICAM, VCAM, and E-Selectin was assessed by flow cytometry. Transcriptome analysis of genes promoting angiogenesis was performed by real-time PCR. Finally, a MSD multiplex angiogenic assay was performed on PsA SFC and RA SFC supernatants. Results Macroscopic synovitis and vascularity were similar in PsA and RA patients; however, significant differences in vascular morphological pattern were recorded with tortuous, elongated vessels observed in PsA compared to straight regular branching vessels observed in RA. Transcriptome analysis showed strong upregulation of the pro-angiogenic signature in HUVEC primed with PsA SFC-CM compared to RA SFC-CM and basal control. In parallel, paired PsA SFC-CM significantly induced HUVEC tube formation compared to that of RA SFC-CM. Furthermore, PsA SFC-CM induced HUVEC migration was paralleled by a significant induction in VEGFA, PFKFB3, ICAM-1, and MMP3 mRNA expression. A significant increase in PBMC adhesion and cell surface expression of VCAM-1, ICAM-1, and E-Selectin expression was also demonstrated in PsA SFC-CM-primed HUVEC compared to RA SFC-CM. Finally, VEGF, TSLP, Flt-1, and Tie-2 expression was elevated in PsA SFC-CM compared to RA SFC-CM, with no significant difference in other pro-angiogenic mediators including MIP-3, bFGF, PIGF, and MCP-1. Conclusion PsA SFC and RA SFC secreted factors differentially regulate endothelial cell function, with soluble mediators in the PsA joint microenvironment inducing a more pro-angiogenic phenotype compared to the RA.
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Affiliation(s)
- S Fromm
- Department of Molecular Rheumatology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - C C Cunningham
- Department of Molecular Rheumatology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - M R Dunne
- Department of Surgery, Trinity Translational Medicine Institute, St. James's Hospital, Trinity College Dublin, Dublin, Ireland
| | - D J Veale
- Rheumatology EULAR Centre of Excellence, Centre for Arthritis & Rheumatic Diseases, University College Dublin, Dublin, Ireland
| | - U Fearon
- Department of Molecular Rheumatology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland.
| | - S M Wade
- Department of Molecular Rheumatology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland.,Rheumatology EULAR Centre of Excellence, Centre for Arthritis & Rheumatic Diseases, University College Dublin, Dublin, Ireland
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Cunningham CC, Corr EM, McCarthy GM, Dunne A. Intra-articular basic calcium phosphate and monosodium urate crystals inhibit anti-osteoclastogenic cytokine signalling. Osteoarthritis Cartilage 2016; 24:2141-2152. [PMID: 27426968 DOI: 10.1016/j.joca.2016.07.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 06/23/2016] [Accepted: 07/01/2016] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Basic calcium phosphate (BCP) and monosodium urate (MSU) crystals are particulates with potent pro-inflammatory effects, associated with osteoarthritis (OA) and gout, respectively. Bone erosion, due to increased osteoclastogenesis, is a hallmark of both arthropathies and results in severe joint destruction. The aim of this study was to investigate the effect of these endogenous particulates on anti-osteoclastogenic cytokine signalling. METHODS Human osteoclast precursors (OcP) were treated with BCP and MSU crystals prior to stimulation with Interleukin (IL-6) or Interferon (IFN-γ) and the effect on Signal Transducer and Activator of Transcription (STAT)-3 and STAT-1 activation in addition to Mitogen Activated Protein Kinase (MAPK) activation was examined by immunoblotting. Crystal-induced suppressor of cytokine signalling (SOCS) protein and SH-2 containing tyrosine phosphatase (SHP) expression was assessed by real-time polymerase chain reaction (PCR) in the presence and absence of MAPK inhibitors. RESULTS Pre-treatment with BCP or MSU crystals for 1 h inhibited IL-6-induced STAT-3 activation in human OcP, while pre-treatment for 3 h inhibited IFN-γ-induced STAT-1 activation. Both crystals activated p38 and extracellular signal-regulated (ERK) MAPKs with BCP crystals also activating c-Jun N-terminal kinase (JNK). Inhibition of p38 counteracted the inhibitory effect of BCP and MSU crystals and restored STAT-3 phosphorylation. In contrast, STAT-1 phosphorylation was not restored by MAPK inhibition. Finally, both crystals potently induced the expression of SOCS-3 in a MAPK dependent manner, while BCP crystals also induced expression of SHP-1 and SHP-2. CONCLUSION This study provides further insight into the pathogenic effects of endogenous particulates in joint arthropathies and demonstrates how they may contribute to bone erosion via the inhibition of anti-osteoclastogenic cytokine signalling. Potential targets to overcome these effects include p38 MAPK, SOCS-3 and SHP phosphatases.
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Affiliation(s)
- C C Cunningham
- School of Biochemistry & Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Ireland; School of Medicine, Trinity Biomedical Sciences Institute, Trinity College Dublin, Ireland.
| | - E M Corr
- School of Biochemistry & Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Ireland; School of Medicine, Trinity Biomedical Sciences Institute, Trinity College Dublin, Ireland.
| | - G M McCarthy
- Mater Misericordiae University Hospital, Dublin 7, Ireland.
| | - A Dunne
- School of Biochemistry & Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Ireland; School of Medicine, Trinity Biomedical Sciences Institute, Trinity College Dublin, Ireland.
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Dunne A, Mielke LA, Allen AC, Sutton CE, Higgs R, Cunningham CC, Higgins SC, Mills KHG. A novel TLR2 agonist from Bordetella pertussis is a potent adjuvant that promotes protective immunity with an acellular pertussis vaccine. Mucosal Immunol 2015; 8:607-17. [PMID: 25315966 DOI: 10.1038/mi.2014.93] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 09/09/2014] [Indexed: 02/04/2023]
Abstract
Bordetella pertussis causes whooping cough, a severe and often lethal respiratory infection in infants. A recent resurgence of pertussis has been linked with waning or suboptimal immunity induced with acellular pertussis vaccines (Pa) that were introduced to most developed countries in the 1990s because of safety concerns around the use of whole-cell pertussis vaccines (Pw). Pa are composed of individual B. pertussis antigens absorbed to alum and promote strong antibody, T helper type 2 (Th2) and Th17 responses, but are less effective at inducing cellular immunity mediated by Th1 cells. In contrast, Pw, which include endogenous Toll-like receptor (TLR) agonists, induce Th1 as well as Th17 responses. Here we report the identification and characterization of novel TLR2-activating lipoproteins from B. pertussis. These proteins contain a characteristic N-terminal signal peptide that is unique to Gram-negative bacteria and we demonstrate that one of these lipoproteins, BP1569, activates murine dendritic cells and macrophages and human mononuclear cells via TLR2. Furthermore, we demonstrated that a corresponding synthetic lipopeptide LP1569 has potent immunostimulatory and adjuvant properties, capable of enhancing Th1, Th17, and IgG2a antibody responses induced in mice with an experimental Pa that conferred superior protection against B. pertussis infection than an equivalent vaccine formulated with alum.
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Affiliation(s)
- A Dunne
- Molecular Immunology Group, School of Biochemistry and Immunology and Immunology Research Centre, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - L A Mielke
- Immune Regulation Research Group, School of Biochemistry and Immunology and Immunology Research Centre, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - A C Allen
- Immune Regulation Research Group, School of Biochemistry and Immunology and Immunology Research Centre, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - C E Sutton
- Immune Regulation Research Group, School of Biochemistry and Immunology and Immunology Research Centre, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - R Higgs
- Immune Regulation Research Group, School of Biochemistry and Immunology and Immunology Research Centre, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - C C Cunningham
- Molecular Immunology Group, School of Biochemistry and Immunology and Immunology Research Centre, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - S C Higgins
- Immune Regulation Research Group, School of Biochemistry and Immunology and Immunology Research Centre, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - K H G Mills
- Immune Regulation Research Group, School of Biochemistry and Immunology and Immunology Research Centre, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
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Smith JE, Co C, McIntosh S, Cunningham CC. Chronic binge-like moderate ethanol drinking in rats results in widespread decreases in brain serotonin, dopamine, and norepinephrine turnover rates reversed by ethanol intake. J Neurochem 2010; 105:2134-55. [PMID: 18284613 DOI: 10.1111/j.1471-4159.2008.05296.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This research was initiated to assess the turnover rates (TORs) of dopamine (DA), norepinephrine (NA), serotonin (5-HT), aspartate, glutamate, and GABA in brain regions during rodent ethanol/sucrose (EtOH) and sucrose (SUC) drinking and in animals with a history of EtOH or SUC drinking to further characterize the neuronal systems that underlie compulsive consumption. Groups of five male rats were used, with two trained to drink EtOH solutions, two to drink SUC and one to serve as a non-drinking control. When stable drinking patterns were obtained, rats were pulse labeled intravenously and killed 60 or 90 min later and the TORs of DA, norepinephrine, 5-HT, aspartate, glutamate, and GABA determined in brain regions. Changes in the TOR of 5-HT, DA, and NA were detected specific to EtOH drinking, SUC drinking or a history of EtOH or SUC drinking. An acute EtOH deprivation effect was detected that was mostly reversed with EtOH drinking. These results suggest that binge-like drinking of moderate amounts of EtOH produces a deficit in neuronal function that could set the stage for the alleviation of anhedonic stimuli with further EtOH intake that strengthen EtOH seeking behaviors which may contribute to increased EtOH use in at risk individuals.
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Affiliation(s)
- James E Smith
- Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Wake Forest University, Winston-Salem, North Carolina 27157-1083, USA.
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Brown RE, Cunningham CC. Association of the bovine cardiac mitochondrial ATPase with phospholipids: reconstitution and phospholipid exchange studies. Biophys J 2010; 37:91-3. [PMID: 19431519 DOI: 10.1016/s0006-3495(82)84615-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Eager RM, Cunningham CC, Senzer N, Richards DA, Raju RN, Jones B, Uprichard M, Nemunaitis J. Phase II trial of talabostat and docetaxel in advanced non-small cell lung cancer. Clin Oncol (R Coll Radiol) 2009; 21:464-72. [PMID: 19501491 DOI: 10.1016/j.clon.2009.04.007] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 04/01/2009] [Accepted: 04/28/2009] [Indexed: 10/20/2022]
Abstract
AIMS Currently available therapies do improve survival in advanced stage non-small cell lung cancer (NSCLC), but only to a limited degree. Talabostat mesilate (PT-100) is an orally available amino boronic dipeptide that specifically inhibits dipeptidyl peptidases (including fibroblast activation protein) and enhances an immune response. The aim of this study was to determine the efficacy and safety of talabostat in NSCLC patients. MATERIALS AND METHODS A phase II trial was conducted to evaluate talabostat in combination with docetaxel in patients with advanced NSCLC after failure of previous platinum-based chemotherapy. In total, 42 patients were enrolled. RESULTS Talabostat was well tolerated. Two patients achieved a partial response and one achieved a complete response. CONCLUSION There was no evidence that talabostat enhanced the clinical activity of docetaxel in patients with NSCLC.
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Affiliation(s)
- R M Eager
- Mary Crowley Cancer Research Centers, Dallas, Texas, USA
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Patel VB, Spencer CH, Young TA, Lively MO, Cunningham CC. Effects of 4-hydroxynonenal on mitochondrial 3-hydroxy-3-methylglutaryl (HMG-CoA) synthase. Free Radic Biol Med 2007; 43:1499-507. [PMID: 17964421 PMCID: PMC2121608 DOI: 10.1016/j.freeradbiomed.2007.08.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Revised: 08/03/2007] [Accepted: 08/07/2007] [Indexed: 02/06/2023]
Abstract
Chronic ethanol consumption causes increased production of reactive oxygen species in hepatic mitochondria accompanied by elevations in products of lipid peroxidation such as 4-hydroxynonenal (4-HNE). In the current study we investigated the effects of chronic ethanol consumption on a prominent protein-4-HNE adduct in liver mitochondria. Male Sprague-Dawley rats were fed a liquid diet for 31 days in which ethanol constituted 36% of total calories. Immunoblot analyses of liver mitochondria from ethanol-fed and control animals, using an antibody to a 4-HNE-protein adduct, demonstrated elevated 4-HNE binding (+50%) to a mitochondrial protein of approximately 55 kDa due to chronic ethanol consumption. Analysis of this protein using AspN digestion and tandem mass spectrometry identified it as the mitochondrial form of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase. Activity of the activated form of this enzyme was unchanged in livers from ethanol-fed animals, but the protein level was elevated by 36%, which suggests a compensatory mechanism to maintain constant levels of synthase activity in the mitochondrion in the face of continuous inactivation by 4-HNE. Treatment of isolated mitochondria with 4-HNE demonstrated that the enzyme activity decreased as a function of 4-HNE concentration and with time of exposure. This study demonstrates that ethanol consumption increases the formation of a 4-HNE adduct with mitochondrial HMG-CoA synthase, which has the potential to inactivate the enzyme in situ.
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Affiliation(s)
- Vinood B. Patel
- Department of Biomedical Sciences, University of Westminster, 115 New Cavendish Street, London W1W 6UW UK
| | - Christina H. Spencer
- Department of Biochemistry, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina, 27157-1016
| | - Tracey A. Young
- Department of Biochemistry, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina, 27157-1016
| | - Mark O. Lively
- Department of Biochemistry, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina, 27157-1016
| | - Carol C. Cunningham
- Department of Biochemistry, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina, 27157-1016
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Weindling AM, Cunningham CC, Glenn SM, Edwards RT, Reeves DJ. Additional therapy for young children with spastic cerebral palsy: a randomised controlled trial. Health Technol Assess 2007; 11:iii-iv, ix-x, 1-71. [PMID: 17462166 DOI: 10.3310/hta11160] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVES To investigate whether, in the short and medium term, additional support by (a) a physiotherapy assistant improved physical function in young children with spastic cerebral palsy and (b) a family support worker improved family functioning. DESIGN This was a multi-centre randomised controlled trial (RCT) with blinded assessments and a cost-effectiveness analysis. The children studied had spastic cerebral palsy that was the consequence of perinatal adversity. All were less than 4 years old on entry to the study. SETTING In the child development centre and in the home. PARTICIPANTS Seventy-six families completed the intervention period. Forty-three families were reassessed 6 months after the end of the intervention and 34 of these after a further 6-month period. INTERVENTIONS Randomisation was to: (a) a group who received extra physiotherapy from a physiotherapy assistant; (b) a group who received standard physiotherapy; and (c) a group where the child received standard physiotherapy and the family was also visited by a family support worker. Children in all groups continued to receive standard physiotherapy in addition to the study interventions. MAIN OUTCOME MEASURES The child outcome measures were motor functioning, developmental status and adaptive functioning. The family outcome measures were self-reported maternal stress, level of family needs and parental satisfaction. RESULTS There was no evidence that additional physical therapy for 1 hour per week for 6 months by a physiotherapy assistant improved any child outcome measure in the short or medium term. Intervention by a family support worker did not have a clinically significant effect on parental stress or family needs. Over the 6-month period the total cost of services for each child ranged from 250 pounds to 6750 pounds, with higher costs associated with children with more severe impairments. No significant relationship was found between measures of intensity of services received by the children and families and the main outcome measures. Low-functioning children, in terms of both motor and cognitive function, were more likely to receive more services in terms of range and frequency. Parents generally reported high satisfaction ratings after all interventions and some stated that the interventions had benefited the child and/or the family. There was therefore a discrepancy between the perceptions of these parents and the objective, quantitative measurements. The family support workers identified a small number of families who were experiencing considerable family problems, but who had not been referred for appropriate support by any other agency. CONCLUSIONS The findings of this study provide support for the current literature that there was no evidence that additional intervention (in this case by a physiotherapy assistant or family support worker) helped the motor or general development of young children with spastic cerebral palsy. Nor was there any quantitative evidence that providing extra family support helped levels of parental stress and family needs. The implication was that the provision of extra physical therapy does not necessarily improve the motor function of a young child with cerebral palsy and additional family support should not automatically be assumed to be beneficial. In addition, no significant association was found between the intensity of the local services provided and any outcome measure, other than a slight association with lowered family needs. The provision of local services was related to the severity of the child's impairments and not to family difficulties. A small group of families with complex family problems needed more service input. There was a wide range in the costs of services. Research is needed to examine what 'sufficient' levels of provision or therapy might be for which children and which families. A time series of different levels of input and outcomes would provide valuable information for practitioners. It is also recommended that future assessments of therapies of this type adopt a similar multifaceted approach, which is likely to be more suitable than a simple RCT for the evaluation of clinical interventions where the effects are complex. The most appropriate measures of outcome should be used, including assessment of provision of information and emotional support for families.
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Affiliation(s)
- A M Weindling
- School of Reproductive and Developmental Medicine, University of Liverpool, UK
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Young TA, Bailey SM, Van Horn CG, Cunningham CC. Chronic ethanol consumption decreases mitochondrial and glycolytic production of ATP in liver. Alcohol Alcohol 2006; 41:254-60. [PMID: 16571619 DOI: 10.1093/alcalc/agl017] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
AIMS The synthesis of ATP in the liver of the chronic ethanol consumer is suppressed, particularly if the tissue becomes hypoxic. Moreover, the perivenous region of the liver lobule becomes even more oxygen deficient as a result of ethanol consumption. Synthesis of ATP in the perivenous region of the lobule may be depressed in the chronic ethanol consumer due to decreases in both mitochondrial and glycolytic activities. In this study the effects of hypoxia on hepatic ATP levels derived from synthesis by both oxidative phosphorylation and the glycolytic mechanisms were investigated. METHODS Rats were pair-fed liquid diets containing 36% of calories as ethanol or an isocaloric control diet. The contributions of glycolysis and mitochondria to ATP production were assessed employing oligomycin, an inhibitor of oxidative phosphorylation. In order to localize the ethanol-elicited lesion in the glycolytic pathway, the metabolism of [3-(3)H] D-glucose was followed in hepatocytes from ethanol-fed and control animals. RESULTS Under both hypoxic and normoxic conditions ATP losses were due to decreases in both glycolytic and mitochondrial ATP production. The rate of production of tritiated water from [3-(3)H] D-glucose was significantly decreased in hepatocytes from ethanol-fed animals, which indicates there is an ethanol-elicited lesion in glycolysis between glucose and glyceraldehyde-3-phosphate.
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Affiliation(s)
- Tracey A Young
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
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Davies SS, Zackert W, Luo Y, Cunningham CC, Frisard M, Roberts LJ. Quantification of dinor, dihydro metabolites of F2-isoprostanes in urine by liquid chromatography/tandem mass spectrometry. Anal Biochem 2005; 348:185-91. [PMID: 16309621 DOI: 10.1016/j.ab.2005.10.012] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2005] [Revised: 10/04/2005] [Accepted: 10/05/2005] [Indexed: 11/18/2022]
Abstract
The F2-isoprostanes (F2-IsoP) are a series of prostaglandin (PG)-F2-like compounds that are produced by free-radical-mediated oxidation of arachidonic acid. One F2-IsoP with potent biological activity is 15-F2t-IsoP and increased levels of 15-F(2t)-IsoP have been measured in several diseases. The major urinary metabolite of 15-F2t-IsoP (8-iso-PGF(2alpha)) is 2,3-dinor-5,6-dihydro-15-F2t-IsoP (15-F2t-IsoP-M). Previously, we developed a stable isotope dilution gas chromatography/negative chemical ionization/mass spectrometry (MS) assay for 15-F2t-IsoP-M, which, while highly sensitive, required time-consuming derivatization and thin-layer chromatography purification. We now report the development of a more rapid high-performance liquid chromatography method coupled to electrospray ionization-tandem mass spectrometry (LC/MS/MS) to analyze all of the dinor,dihydro metabolites of the F2-IsoP isomers (F2-IsoP-M). The precision of this assay was +/-5.0% and the accuracy 80%. The assay remained linear over a range of 1-100 ng injected onto the LC column. Levels of F2-IsoP-M determined by the LC/MS/MS assay method significantly correlated with levels of 15-F2t-IsoP-M determined by the GC/MS assay (R = 0.77y = 67.2x-0.5). The levels of F2-IsoP-M detected in spot urines from 40 normal subjects were 38.1+/-19.1 ng/mg creatinine (mean+/-SD). This method provides an accurate and rapid assay to assess oxidative status in vivo.
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Affiliation(s)
- Sean S Davies
- Department of Pharmacology, Vanderbilt University, Nashville, TN 27232, USA.
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Ivester P, Shively CA, Register TC, Grant KA, Reboussin DM, Cunningham CC. The effects of moderate ethanol consumption on the liver of the monkey, Macaca fascicularis. Alcohol Clin Exp Res 2004; 27:1831-7. [PMID: 14634501 DOI: 10.1097/01.alc.0000095633.26284.fa] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Although evidence has accumulated for the cardioprotective effects of moderate ethanol consumption, little is known about the effects on the liver of consuming the equivalent of two drinks per day. The objective of this study was to determine the effects of moderate ethanol administration on the hepatic content of enzymes involved in ethanol oxidation, on hepatic lipid accumulation, and on serum markers of liver function/damage in the monkey, Macaca fascicularis. METHODS Ovariectomized, adult monkeys were maintained for 34 months on an atherogenic diet containing cholesterol 1.21 mg/kJ. They were trained to drink ethanol plus vehicle at a dose of 0.5 g/kg body weight, which was administered 5 days a week for 2 years. Blood was collected for ethanol concentrations (1 hr after ethanol administration) and was also assayed for gamma-glutamyltransferase, alanine aminotransferase (ALT), and alkaline phosphatase (ALP) activities. Liver obtained at necropsy was analyzed for triglyceride and cholesterol contents and for alcohol dehydrogenase, cytochrome P450 2E1, and cytochrome P450 3A4 by Western blots. RESULTS The blood ethanol concentrations measured 1 hr after ethanol administration were relatively constant over the 2-year dosing period. Hepatic levels of alcohol dehydrogenase and the cytochrome P450s were not significantly different between ethanol-consuming animals and control animals. Ethanol-associated increases in liver triglyceride were not significant due to high variability in hepatic lipid content in both the controls and ethanol consumers. However, covariance analyses using pretreatment concentrations of plasma cholesterol and apolipoprotein A-I suggested that the ethanol-related increase in hepatic free cholesterol was significant. Relative to controls, alcohol consumers had higher levels of serum ALT and a transient increase in ALP at 5 months. CONCLUSIONS The observations made in this study on primates administered an atherogenic diet suggest that moderate ethanol ingestion has modest effects on the liver, including slightly increased ALT and ALP values. However, additional studies will be required to verify that this level of consumption is hepatotoxic when ingested over extended periods. This is still a concern because some human studies suggest that levels of ethanol considered to be cardioprotective cause liver injury when consumed over a lifetime.
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Affiliation(s)
- Priscilla Ivester
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157-1016, USA
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Affiliation(s)
- R Newton
- Royal Manchester Children's Hospital, Pendlebury, Manchester M27 4HA, UK.
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Cunningham CC, Van Horn CG. Energy availability and alcohol-related liver pathology. Alcohol Res Health 2003; 27:291-9. [PMID: 15540800 PMCID: PMC6668872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Alcohol consumption alters the metabolism of the most common type of cell found in the liver, the hepatocyte. The presence of alcohol in the body causes the liver to use more oxygen-for example, when breaking down the alcohol. Increased oxygen use, in turn, causes oxygen deficits in several key cells, particularly in hepatocytes located near the small hepatic veins. These veins return blood to the heart for re-oxygenation after it has passed through the liver. Hepatocytes surrounding these veins are the first to show signs of liver disease. The damage induced by oxygen deficits may be exacerbated by alcohol-induced deficits in other components that are essential for cell survival. For example, adenosine triphosphate (ATP), the cell's main source of energy, is generated primarily during the course of two sets of metabolic reactions: glycolysis and the mitochondrial oxidative phosphorylation process. Alcohol consumption may interfere with both of these pathways of ATP production through several mechanisms. An inadequate supply of ATP impairs the cell's ability to perform critical functions, including the repair of alcohol-induced cell damage, and may therefore contribute to cell death and alcoholic liver disease.
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Affiliation(s)
- Carol C Cunningham
- Department ofBiochemistry at Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
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Cahill A, Cunningham CC, Adachi M, Ishii H, Bailey SM, Fromenty B, Davies A. Effects of alcohol and oxidative stress on liver pathology: the role of the mitochondrion. Alcohol Clin Exp Res 2002. [PMID: 12068261 DOI: 10.1111/j.1530-0277.2002.tb02621.x] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This article represents the proceedings of a symposium at the 2001 Research Society on Alcoholism meeting in Montreal, Canada. The chairs were Alan Cahill and Carol C. Cunningham. The presentations were (1) Mitochondrial regulation of ethanol-induced hepatocyte apoptosis: possible involvement of proapoptotic Bcl-2 family protein Bax, by Masayuki Adachi and Hiromasa Ishii; (2) Effects of ethanol on mitochondrial reactive oxygen species production and oxidative protein modification, by Shannon M. Bailey; (3) Acute ethanol binges elicit widespread oxidative mitochondrial DNA damage and depletion: protective effects of antioxidants and inhibitors of ethanol metabolism, by Bernard Fromenty; and (4) Effects of chronic ethanol consumption upon hepatic mtDNA oxidative modification and depletion, by Alan Cahill and Adrian Davies.
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Affiliation(s)
- Alan Cahill
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
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Young TA, Cunningham CC, Bailey SM. Reactive oxygen species production by the mitochondrial respiratory chain in isolated rat hepatocytes and liver mitochondria: studies using myxothiazol. Arch Biochem Biophys 2002; 405:65-72. [PMID: 12176058 DOI: 10.1016/s0003-9861(02)00338-7] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Increased production of reactive oxygen species (ROS) by the mitochondrion has been implicated in the pathogenesis of numerous liver diseases. However, the exact sites of ROS production within liver mitochondria and the electron transport chain are still uncertain. To determine the sites of ROS generation in liver mitochondria we evaluated the ability of a variety of mitochondrial respiratory inhibitors to alter the steady state levels of ROS generated within the intact hepatocyte and in isolated mitochondria. Treatment with myxothiazol alone at concentrations that significantly inhibit respiration dramatically increased the steady-state levels of ROS in hepatocytes. Similar results were also observed in isolated mitochondria oxidizing succinate. Coincubation with antimycin or rotenone had no effect on myxothiazol-induced ROS levels. Myxothiazol stimulation of ROS was mitochondrial in origin as demonstrated by the colocalization of MitoTracker Red and dichlorofluorescein staining using confocal microscopy. Furthermore, diphenyliodonium, an inhibitor that blocks electron flow through the flavin mononucleotide of mitochondrial complex I and other flavoenzymes, significantly attenuated the myxothiazol-induced increase in hepatocyte ROS levels. Together, these data suggest that in addition to the ubiquinone-cytochrome bc(1) complex of complex III, several of the flavin-containing enzymes or iron-sulfur centers within the mitochondrial electron transport chain should also be considered sites of superoxide generation in liver mitochondria.
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Affiliation(s)
- Tracey A Young
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
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Abstract
Chronic ethanol consumption decreases the synthesis of all 13 polypeptides encoded by the hepatic mitochondrial genome. This alteration in mitochondrial protein synthesis is due to modifications in mitochondrial ribosomes. In the current study, the nature of these alterations was investigated by determining some of the hydrodynamic properties, namely sedimentation coefficient, shape, and mass of mitochondrial ribosomes. The effect of ethanol consumption on the capacity for mitochondrial ribosomes to translate proteins was also determined using an in vitro Poly (U) assay system. Rats were fed the Lieber-DeCarli diet for 31 days with ethanol as 36% of total calories. The sedimentation coefficient, measured by sedimentation velocity analyses, was slightly, but significantly lower in ethanol mitochondrial ribosomes (53.2 +/- 0.5S) when compared with pair-fed controls (54.1 +/- 0.5S) (P = 0.04). Mitochondrial ribosomes from ethanol-fed animals also had a greater tendency to dissociate into subunits. The diffusion coefficient, determined by dynamic light scattering, was lower in mitochondrial ribosomes from ethanol-fed rats than pair-fed controls and this indicated a significantly greater diameter for ethanol ribosomes (42.1 +/- 0.2 nm) than for preparations from pair-fed controls (39.1 +/- 0.5 nm; P = 0.008). These alterations to ethanol mitochondrial ribosomes occurred despite no change in molecular mass, which suggested a significant ethanol-related shape change in the ribosomes. The translation capacity of mitochondrial ribosome preparations from ethanol-fed animals was markedly reduced due to dissociation of the monosome into light and heavy subunits. In summary, these observations demonstrate that chronic ethanol consumption causes significant structural and functional alterations to mitochondrial ribosomes. The loss in ribosome function leads to impaired mitochondrial polypeptide synthesis and is an example of a pathology giving rise to an alteration in the mitochondrial ribosome structure.
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Affiliation(s)
- Vinood B Patel
- Department of Biochemistry, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina 27157-1016, USA
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Abstract
The importance of oxidative stress in the development of alcoholic liver disease has long been appreciated. The mechanism by which ethanol triggers an increase in reactive oxygen species in the liver is complex, however, recent findings suggest that the mitochondrion may contribute significantly to the overall increase in oxidant levels in hepatocytes exposed to ethanol acutely or chronically. This review is focused on observations which indicate that the ability of ethanol to increase mitochondrial reactive oxygen species production is linked to its metabolism via oxidative processes and/or ethanol-related alterations to the mitochondrial electron transport chain. Furthermore, the capacity of ethanol-elicited increases in reactive oxygen species to oxidatively modify and inactivate mitochondrial proteins is highlighted as a mechanism by which ethanol might further disrupt the structure and function of mitochondria.
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Affiliation(s)
- Shannon M Bailey
- Department of Environmental Health Sciences, School of Public Health, University of Alabama at Birmingham, 1530 3rd Ave. South, RPHB 317, Birmingham, AL 35294, USA.
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Abstract
The rational design of therapies for treating nerve injuries requires an understanding of the mechanisms underlying neurite extension. Neurite motility is driven by actin polymerization; however, the mechanisms are not clearly understood. One actin accessory protein, gelsolin, is involved with remodeling the cytoskeleton, although its role in cell motility is unclear. We report a two-fold upregulation of gelsolin upon differentiation with nerve growth factor. Cells that were genetically modified to overexpress gelsolin have longer neurites and a greater neurite motility rate compared to controls. These data suggest that gelsolin plays an important role in neurite outgrowth.
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Affiliation(s)
- E J Furnish
- Department of Chemical Engineering, University of Texas at Austin, 78712, USA
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Cunningham CC, Vegners R, Bucki R, Funaki M, Korde N, Hartwig JH, Stossel TP, Janmey PA. Cell permeant polyphosphoinositide-binding peptides that block cell motility and actin assembly. J Biol Chem 2001; 276:43390-9. [PMID: 11533030 DOI: 10.1074/jbc.m105289200] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Polyphosphoinositides (PPIs) affect the localization and activities of many cellular constituents, including actin-modulating proteins. Several classes of polypeptide sequences, including pleckstrin homology domains, FYVE domains, and short linear sequences containing predominantly hydrophobic and cationic residues account for phosphoinositide binding by most such proteins. We report that a ten-residue peptide derived from the phosphatidylinositol 4,5-bisphosphate (PIP(2)) binding region in segment 2 of gelsolin, when coupled to rhodamine B has potent PIP(2) binding activity in vitro; crosses the cell membrane of fibroblasts, platelets, melanoma cells, and neutrophils by a process not involving endocytosis; and blocks cell motility. This peptide derivative transiently disassembles actin filament structures in GFP-actin-expressing NIH3T3 fibroblasts and prevents thrombin- or chemotactic peptide-stimulated actin assembly in platelets and neutrophils, respectively, but does not block the initial [Ca(2+)] increase caused by these agonists. The blockage of actin assembly and motility is transient, and cells recover motility within an hour after their immobilization by 5-20 microm peptide. This class of reagents confirms the critical relation between inositol lipids and cytoskeletal structure and may be useful to probe the location and function of polyphosphoinositides in vivo.
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Affiliation(s)
- C C Cunningham
- Hematology Division, Brigham & Women's Hospital, Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115, USA
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Cunningham CC, Holmlund JT, Geary RS, Kwoh TJ, Dorr A, Johnston JF, Monia B, Nemunaitis J. A Phase I trial of H-ras antisense oligonucleotide ISIS 2503 administered as a continuous intravenous infusion in patients with advanced carcinoma. Cancer 2001. [PMID: 11571742 DOI: 10.1002/1097-0142(20010901)92:5<1265::aid-cncr1447>3.0.co;2-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Abnormal expression of Ras proteins frequently is found with oncogenic transformation making ras a promising therapeutic target. ISIS 2503 is a 20-base antisense phosphorothioate oligodeoxyribonucleotide that specifically downregulates H-ras expression and inhibits tumor cell growth in preclinical studies. Here, the authors report an initial clinical study of the safety and tolerability of an intravenous infusion of ISIS 2503 in patients with advanced cancer. METHODS A continuous intravenous infusion of ISIS 2503 was administered for 14 days every 3 weeks to 23 patients with a variety of solid tumors refractory to standard therapy. The dose of ISIS 2503 was increased in sequential cohorts of patients, as toxicity allowed, until a final dose of 10.0 mg/kg/day of body weight was reached. Toxicity was scored by the National Cancer Institute's Common Toxicity Criteria, and tumor response was monitored after every two treatment cycles. Pharmacokinetic studies were performed in some of the patients up to, and including, the final dose of 10 mg/kg/day/day of body weight. Levels of H-ras mRNA expression also were determined in the circulating lymphocytes of some patients by quantitative reverse transcriptase-polymerase chain reaction. RESULTS A total of 23 patients received 63 cycles of ISIS 2503 at escalating doses to 10.0 mg/kg/day without dose-limiting toxicity and only minimal side effects. Four patients had stabilization of their disease for 6-10 cycles. No consistent decreases in H-ras mRNA levels were observed in peripheral blood lymphocytes. CONCLUSIONS ISIS 2503, an antisense oligonucleotide against H-ras, was well tolerated as a single agent at doses up to 10.0 mg/kg/day by 14-day continuous intravenous infusion. Several patients had stabilization of disease, suggesting that ISIS 2503 had some tumor growth inhibitory effects and future trials of ISIS 2503 in combination with chemotherapy should be considered.
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Cunningham CC, Holmlund JT, Geary RS, Kwoh TJ, Dorr A, Johnston JF, Monia B, Nemunaitis J. A Phase I trial of H-ras antisense oligonucleotide ISIS 2503 administered as a continuous intravenous infusion in patients with advanced carcinoma. Cancer 2001; 92:1265-71. [PMID: 11571742 DOI: 10.1002/1097-0142(20010901)92:5<1265::aid-cncr1447>3.0.co;2-5] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Abnormal expression of Ras proteins frequently is found with oncogenic transformation making ras a promising therapeutic target. ISIS 2503 is a 20-base antisense phosphorothioate oligodeoxyribonucleotide that specifically downregulates H-ras expression and inhibits tumor cell growth in preclinical studies. Here, the authors report an initial clinical study of the safety and tolerability of an intravenous infusion of ISIS 2503 in patients with advanced cancer. METHODS A continuous intravenous infusion of ISIS 2503 was administered for 14 days every 3 weeks to 23 patients with a variety of solid tumors refractory to standard therapy. The dose of ISIS 2503 was increased in sequential cohorts of patients, as toxicity allowed, until a final dose of 10.0 mg/kg/day of body weight was reached. Toxicity was scored by the National Cancer Institute's Common Toxicity Criteria, and tumor response was monitored after every two treatment cycles. Pharmacokinetic studies were performed in some of the patients up to, and including, the final dose of 10 mg/kg/day/day of body weight. Levels of H-ras mRNA expression also were determined in the circulating lymphocytes of some patients by quantitative reverse transcriptase-polymerase chain reaction. RESULTS A total of 23 patients received 63 cycles of ISIS 2503 at escalating doses to 10.0 mg/kg/day without dose-limiting toxicity and only minimal side effects. Four patients had stabilization of their disease for 6-10 cycles. No consistent decreases in H-ras mRNA levels were observed in peripheral blood lymphocytes. CONCLUSIONS ISIS 2503, an antisense oligonucleotide against H-ras, was well tolerated as a single agent at doses up to 10.0 mg/kg/day by 14-day continuous intravenous infusion. Several patients had stabilization of disease, suggesting that ISIS 2503 had some tumor growth inhibitory effects and future trials of ISIS 2503 in combination with chemotherapy should be considered.
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Abstract
Chronic ethanol consumption results in a dramatic decrease in liver glycogen concentrations, which could be related to either a depressed rate of synthesis or an increased rate of breakdown. Earlier studies suggested that there is not an increase in the rate of glycogenolysis as glycogen phosphorylase activities are not elevated. In the present study it was observed that the incorporation of radiolabeled glucose into glycogen was significantly depressed in hepatocytes from ethanol-fed rats under both anaerobic and aerobic conditions. Chronic ethanol consumption decreased the total glycogen synthase (a + b) activity, which correlated closely with a loss in glycogen synthase protein. However, glycogen synthase messenger RNA levels were not depressed, which indicated posttranscriptional modifications affecting both activity and protein levels. The concentration of glucose transporter 1 was also decreased due to ethanol consumption, but glucose transporter 2 levels were not altered. This latter result suggests that glucose transport in the perivenous region of the liver lobule may be decreased in chronic ethanol consumers. The alterations in glucose transport protein and glycogen synthesis observed in this study may contribute to lowered glycogen synthesis, but do not appear to account for the magnitude of the decreases in glycogen levels and rate of synthesis. Indeed, ethanol effects on glycogen metabolism are likely to be exerted at several levels, including posttranslational modulation of enzyme activities.
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Affiliation(s)
- C G Van Horn
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157-1016, USA
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Abstract
When a dielectric object is placed between two opposed, nonfocused laser beams, the total force acting on the object is zero but the surface forces are additive, thus leading to a stretching of the object along the axis of the beams. Using this principle, we have constructed a device, called an optical stretcher, that can be used to measure the viscoelastic properties of dielectric materials, including biologic materials such as cells, with the sensitivity necessary to distinguish even between different individual cytoskeletal phenotypes. We have successfully used the optical stretcher to deform human erythrocytes and mouse fibroblasts. In the optical stretcher, no focusing is required, thus radiation damage is minimized and the surface forces are not limited by the light power. The magnitude of the deforming forces in the optical stretcher thus bridges the gap between optical tweezers and atomic force microscopy for the study of biologic materials.
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Affiliation(s)
- J Guck
- Center for Nonlinear Dynamics, Department of Physics, University of Texas at Austin, Texas 78712, USA.
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Abstract
The mitochondrion is the subcellular organelle affected earliest during the development of alcoholic liver disease. As a result of chronic ethanol consumption mitochondrial protein synthesis is decreased significantly due to a depression in the functioning of the mitochondrial ribosome. This causes a significant decrease in the concentrations of the thirteen mitochondria gene products, all of which are components of the oxidative phosphorylation system. Consequently, there is a depression in the rate at which ATP is synthesized in hepatic mitochondria. In addition to this loss in function, hepatic mitochondria either acutely or chronically exposed to ethanol generate increased levels of reactive oxygen species (ROS). This elevation in ROS has been demonstrated in both isolated mitochondria and hepatocytes. The increase in mitochondrial ROS production accompanying acute ethanol exposure is due to mitochondrial associated reoxidation of NADH produced during ethanol and acetaldehyde metabolism. The elevation in ROS generation observed in mitochondria from chronic ethanol consumers is likely due to decreases in mitochondrial-derived electron transport components, which in turn results in higher levels of the semiquinone forms of flavin mononucleotide and ubiquinone. Both these semiquinones readily donate electrons to molecular oxygen to form superoxide.
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Affiliation(s)
- C C Cunningham
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, N.C. 27157-1016, USA.
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Cunningham CC, Preedy VR, Paice AG, Hesketh JE, Peters TJ, Patel VB, Volpi E, Mawatari K, Masaki H, Mori M, Torii K. Ethanol and Protein Metabolism. Alcohol Clin Exp Res 2001. [DOI: 10.1111/j.1530-0277.2001.tb02406.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Cunningham CC, Preedy VR, Paice AG, Hesketh JE, Peters TJ, Patel VB, Volpi E, Mawatari K, Masaki H, Mori And M, Torii K. Ethanol and protein metabolism. Alcohol Clin Exp Res 2001; 25:262S-268S. [PMID: 11391081 DOI: 10.1097/00000374-200105051-00042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This article represents the proceedings of a workshop at the 2000 ISBRA Meeting in Yokohama, Japan. The chairs were Carol C. Cunningham and Victor R. Preedy. The presentations were (1) Ribosomal content, ribosomal localization and the levels of ribosomal protein mRNA and rRNA in rat skeletal muscle exposed to ethanol, by Alistair G. Paice, John E. Hesketh, Timothy J. Peters, and Victor R. Preedy; (2) Altered hepatic mitochondrial ribosome structure after chronic ethanol administration, by Vinood B. Patel and Carol C. Cunningham; (3) Clinical aspects of hepatic protein metabolism and alcohol, by Elena Volpi; and (4) Effects of oral intake of alanine plus glutamine on ethanol metabolism and ethanol-related depression in motor activity, by Kazunori Mawatari, H. Masaki, M. Mori, and Kunio Torii.
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MESH Headings
- Alanine/pharmacology
- Animals
- Central Nervous System Depressants/pharmacology
- Ethanol/pharmacology
- Glutamine/pharmacology
- Humans
- Liver/drug effects
- Liver/metabolism
- Mitochondria, Liver/drug effects
- Mitochondria, Liver/metabolism
- Motor Activity/drug effects
- Motor Activity/physiology
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- RNA, Messenger/drug effects
- RNA, Messenger/metabolism
- RNA, Ribosomal, 18S/drug effects
- RNA, Ribosomal, 18S/metabolism
- Ribosomal Proteins/drug effects
- Ribosomal Proteins/metabolism
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Affiliation(s)
- C C Cunningham
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA.
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Bailey SM, Patel VB, Young TA, Asayama K, Cunningham CC. Chronic ethanol consumption alters the glutathione/glutathione peroxidase-1 system and protein oxidation status in rat liver. Alcohol Clin Exp Res 2001; 25:726-33. [PMID: 11371722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
BACKGROUND Alcohol-induced liver damage is associated with oxidative stress, which might be linked to disturbances in liver antioxidant defense mechanisms. The effect of chronic ethanol consumption on the mitochondrial and cytosolic glutathione/glutathione peroxidase-1 (GSHPx-1) system and oxidative modification of proteins was therefore studied in the rat. METHODS Male Sprague-Dawley rats were fed liquid diets that provided 36% total calories as ethanol for at least 31 days. Pair-fed controls received isocaloric diets with ethanol calories substituted with maltose-dextrins. Mitochondrial and cytosolic fractions were prepared from livers and assayed for GSHPx-1 and glutathione reductase activities and total and oxidized concentrations of glutathione. Catalase activity was measured in the postmitochondrial supernatant. Levels of GSHPx-1, lactate dehydrogenase, and the beta subunit of the F1 portion of the ATP synthase protein were determined by western blot analysis. Concentrations of mitochondrial and cytosolic protein carbonyls were measured to assess ethanol-induced oxidation of proteins. RESULTS Chronic ethanol consumption significantly decreased cytosolic and mitochondrial GSHPx-1 activities by 40% and 30%, respectively. Levels of GSHPx-1 protein in cytosol were unaffected by ethanol feeding, whereas there was a small decrease in GSHPx-1 protein levels in mitochondria isolated from ethanol-fed rats. Glutathione reductase activities were increased in both intracellular compartments and catalase activity was increased as a consequence of ethanol exposure. Cytosolic total glutathione was mildly decreased, whereas ethanol feeding increased mitochondrial levels of total glutathione. Chronic ethanol feeding significantly increased both cytosolic and mitochondrial concentrations of protein carbonyls by 30% and 60%, respectively. CONCLUSIONS This study demonstrates that chronic ethanol-induced alterations in the glutathione/GSHPx-1 antioxidant system might promote oxidative modification of liver proteins, namely those of the mitochondrion, which could contribute to the adverse effects of ethanol on the liver.
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Affiliation(s)
- S M Bailey
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157-1016, USA.
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Sun AY, Ingelman-Sundberg M, Neve E, Matsumoto H, Nishitani Y, Minowa Y, Fukui Y, Bailey SM, Patel VB, Cunningham CC, Zima T, Fialova L, Mikulikova L, Popov P, Malbohan I, Janebova M, Nespor K, Sun GY. Ethanol and Oxidative Stress. Alcohol Clin Exp Res 2001. [DOI: 10.1111/j.1530-0277.2001.tb02402.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Bailey SM, Patel VB, Young TA, Asayama K, Cunningham CC. Chronic Ethanol Consumption Alters the Glutathione/Glutathione Peroxidase-1 System and Protein Oxidation Status in Rat Liver. Alcohol Clin Exp Res 2001. [DOI: 10.1111/j.1530-0277.2001.tb02273.x] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Sun AY, Ingelman-Sundberg M, Neve E, Matsumoto H, Nishitani Y, Minowa Y, Fukui Y, Bailey SM, Patel VB, Cunningham CC, Zima T, Fialova L, Mikulikova L, Popov P, Malbohan I, Janebova M, Nespor K, Sun GY. Ethanol and oxidative stress. Alcohol Clin Exp Res 2001; 25:237S-243S. [PMID: 11391077 DOI: 10.1097/00000374-200105051-00038] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
This article represents the proceedings of a workshop at the 2000 ISBRA Meeting in Yokohama, Japan. The chair was Albert Y. Sun. The presentations were (1) Ethanol-inducible cytochrome P-4502E1 in alcoholic liver disease, by Magnus Ingelman-Sundberg and Etienne Neve; (2) Regulation of NF-kappaB by ethanol, by H. Matsumoto, Y. Nishitani, Y. Minowa, and Y. Fukui; (3) Chronic ethanol consumption increases concentration of oxidized proteins in rat liver, by Shannon M. Bailey, Vinood B. Patel, and Carol C. Cunningham; (4) Antiphospholipids antibodies and oxidized modified low-density lipoprotein in chronic alcoholic patients, by Tomas Zima, Lenka Fialova, Ludmila Mikulikova, Ptr Popov, Ivan Malbohan, Marta Janebova, and Karel Nespor; and (5) Amelioration of ethanol-induced damage by polyphenols, by Albert Y. Sun and Grace Y. Sun.
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Affiliation(s)
- A Y Sun
- Department of Pharmacology (AYS, GYS), University of Missouri, Columbia, Missouri 65212, USA
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Abstract
In the present study, the physiochemical properties of rat liver mitochondrial ribosomes were examined and compared with Escherichia coli ribosomes. The sedimentation and translational diffusion coefficients as well as the molecular weight and buoyant density of rat mitochondrial ribosomes were determined. Sedimentation coefficients were established using the time-derivative algorithm (Philo, J. S. (2000) Anal. Biochem. 279, 151-163). The sedimentation coefficients of the intact monosome, large subunit, and small subunit were 55, 39, and 28 S, respectively. Mitochondrial ribosomes had a particle composition of 75% protein and 25% RNA. The partial specific volume was 0.688 ml/g, as determined from the protein and RNA composition. The buoyant density of formaldehyde-fixed ribosomes in cesium chloride was 1.41 g/cm(3). The molecular masses of mitochondrial and E. coli ribosomes determined by static light-scattering experiments were 3.57 +/- 0.14 MDa and 2.49 +/- 0.06 MDa, respectively. The diffusion coefficient obtained from dynamic light-scattering measurements was 1.10 +/- 0.01 x 10(-7) cm(2) s(-1) for mitochondrial ribosomes and 1.72 +/- 0.03 x 10(-7) cm(2) s(-1) for the 70 S E. coli monosome. The hydration factor determined from these hydrodynamic parameters were 4.6 g of water/g of ribosome and 1.3 g/g for mitochondrial and E. coli ribosomes, respectively. A calculated hydration factor of 3.3 g/g for mitochondrial ribosomes was also obtained utilizing a calculated molecular mass and the Svedberg equation. These measurements of solvation suggest that ribosomes are highly hydrated structures. They are also in agreement with current models depicting ribosomes as porous structures containing numerous gaps and tunnels.
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Affiliation(s)
- V B Patel
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157-1016, USA
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Abstract
Chronic ethanol feeding has been shown to decrease the number of functionally active mitochondrial ribosomes by 55%. In this work, 55S mitochondrial ribosomes were isolated from rat liver and their constitutive proteins characterized by two-dimensional polyacrylamide gel electrophoresis and quantified by densitometry. A total of 86 proteins were found to be associated with the mitochondrial ribosome. This compares with 70 isolated from cytoplasmic ribosomes. In addition, mitochondrial ribosomal proteins were found to be significantly less basic than their cytoplasmic counterparts. Chronic ethanol feeding was found to significantly decrease the levels of a number of constitutive proteins of the mitochondrial ribosome when compared to those isolated from pair-fed controls. Sucrose density gradient analyses revealed a significant decrease in the number of intact 55S ribosomes. It is suggested that ethanol-elicited alterations in specific constitutive proteins of the mitochondrial ribosome may lead to impaired assembly of the monosome and that this may result in lower levels of those displaying functional activity.
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Affiliation(s)
- A Cahill
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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Glenn SM, Cunningham CC, Dayus B. Comparison of the 1969 and 1993 standardizations of the Bayley Mental Scales of Infant Development for infants with Down's syndrome. J Intellect Disabil Res 2001; 45:56-62. [PMID: 11168777 DOI: 10.1046/j.1365-2788.2001.00294.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The Bayley Scales of Infant Development (BSID) were re-standardized in 1993 (BSID-II). The present study reports a comparison of the two versions with infants with Down's syndrome (DS). The BSID-II was used for 93 assessments of 54 children with DS (age range = 7-43 months). Comparisons were made with the 1969 standardization for 42 of these assessments, and for 45 assessments of 20 typically developing children aged between 6 and 24 months. The 1993 standardization produced significantly lower mean differences of 1.0 months mental age and 8.4 points mental development index for infants with DS, and 1.5 months mental age and 9.2 points mental development index for the typically developing group. Nineteen per cent more infants with DS had scores below two standard deviations and there was a larger decrement for lower functioning children. Both groups of children have to perform at a higher level to achieve the same relative score on BSID-II compared to BSID. This indicates that caution should be used in comparing cohorts of children tested on different versions of the Bayley scales. In addition, concerns are highlighted regarding the rules for establishing basal and ceiling levels for BSID-II for children with developmental delays.
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Affiliation(s)
- S M Glenn
- School of Health and Human Sciences, John Moores University, Liverpool, UK
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Abstract
Despite parental concerns about young people with Down syndrome talking out loud to themselves (using private speech), there is virtually no research literature on this behavior. In that which exists, investigators have largely interpreted the behavior within a pathological framework. An alternative perspective is that self-talk is developmentally appropriate for these young people. Parents of 78 young people with Down syndrome, age 17 to 24 years, were asked whether their offspring had ever used private speech. Results confirm the universality of private speech and its developmental pattern. No association was found between private speech and behavior problems, communication difficulties, or social isolation. Talking out loud to self by young people with Down syndrome should be seen as adaptive, and not an indication of pathology.
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Affiliation(s)
- S M Glenn
- School of Health and Human Sciences, John Moores University, 79 Tithebarn Street, Liverpool L2 2ER, UK.
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Abstract
Chronic ethanol feeding has been shown to decrease the number of functionally active mitochondrial ribosomes by 55%. In this work, 55S mitochondrial ribosomes were isolated from rat liver and their constitutive proteins characterized by two-dimensional polyacrylamide gel electrophoresis and quantified by densitometry. A total of 86 proteins were found to be associated with the mitochondrial ribosome. This compares with 70 isolated from cytoplasmic ribosomes. In addition, mitochondrial ribosomal proteins were found to be significantly less basic than their cytoplasmic counterparts. Chronic ethanol feeding was found to significantly decrease the levels of a number of constitutive proteins of the mitochondrial ribosome when compared to those isolated from pair-fed controls. Sucrose density gradient analyses revealed a significant decrease in the number of intact 55S ribosomes. It is suggested that ethanol-elicited alterations in specific constitutive proteins of the mitochondrial ribosome may lead to impaired assembly of the monosome and that this may result in lower levels of those displaying functional activity.
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Affiliation(s)
- A Cahill
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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Houston EC, Cunningham CC, Metcalfe E, Newton R. The information needs and understanding of 5-10-year old children with epilepsy, asthma or diabetes. Seizure 2000; 9:340-3. [PMID: 10933989 DOI: 10.1053/seiz.2000.0416] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
This exploratory study compared the information needs and understanding of 25 5-10-year olds with epilepsy with those of 10 children with asthma and 10 with diabetes (of the same age range). The children were interviewed whilst attending specialist clinics by the first author and were unaware of her professional status. All the children had access to specialist nurses and their families had received literature about their condition. The interview covered five main areas: knowledge of their condition, psychological effects, medication, restrictions on lifestyle, where they obtained their information and if they had unanswered questions. The children with epilepsy had far more unanswered questions and felt excluded from discussions with doctors. They also appeared reluctant to tell their friends their diagnosis and, at such a young age, felt stigmatized by their condition. The results highlight a contrast in the understanding of children with epilepsy when compared with those with asthma or diabetes. It is proposed that if a simple biological model were used to explain epilepsy this could aid children's understanding and reduce their reluctance to disclose their diagnosis.
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Affiliation(s)
- E C Houston
- The Royal Manchester Children's Hospital, Hospital Road, Pendlebury, Manchester M27 4HA, UK
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Abstract
Two counterpropagating laser beams were used to significantly stretch soft dielectrics such as cells. The deforming forces act on the surface between the object and the surrounding medium and are considerably higher than the trapping forces on the object. Radiation damage is avoided since a double-beam trap does not require focusing for stable trapping. Ray optics was used to describe the stress profile on the surface of the trapped object. Measuring the total forces and deformations of well-defined elastic objects validated this approach.
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Affiliation(s)
- J Guck
- Center for Nonlinear Dynamics, Department of Physics, University of Texas at Austin, Austin, Texas 78712, USA
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Cunningham CC, Holmlund JT, Schiller JH, Geary RS, Kwoh TJ, Dorr A, Nemunaitis J. A phase I trial of c-Raf kinase antisense oligonucleotide ISIS 5132 administered as a continuous intravenous infusion in patients with advanced cancer. Clin Cancer Res 2000; 6:1626-31. [PMID: 10815879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Raf proteins play a central role in the mitogen-activated protein kinase signaling pathway and hence are involved in oncogenic transformation and tumor cell proliferation. ISIS 5132 is a 20-base antisense phosphorothioate oligodeoxyribonucleotide that specifically down-regulates c-raf expression. We report here an initial study of the safety and tolerability of an i.v. infusion of ISIS 5132 in patients with advanced cancer. A continuous i.v. infusion of ISIS 5132 was administered for 21 days every 4 weeks to 34 patients with a variety of solid tumors refractory to standard therapy. The dose of ISIS 5132 was increased in sequential cohorts of patients, as toxicity allowed, until a final dose of 5.0 mg/kg body weight was reached. Toxicity was scored by common toxicity criteria, and tumor response was monitored. Pharmacokinetic studies were performed for 30 patients treated at doses of < or =4.0 mg/kg/day. The initial dose of ISIS 5132 was 0.5 mg/kg body weight and was successfully increased incrementally to 5.0 mg/kg body weight. Toxicities through the 4.0 mg/kg dose level were not dose limiting. Side effects were minimal and could not be specifically related to ISIS 5132. Two patients had prolonged stabilization of their disease, and one patient with ovarian carcinoma had a significant response with a 97% reduction in CA-125 levels. ISIS 5132, an antisense oligonucleotide against c-raf, was well tolerated at doses up to and including 4.0 mg/kg/day by 21-day continuous i.v. infusion and demonstrated antitumor activity at the doses tested.
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Prat AG, Cunningham CC, Jackson GR, Borkan SC, Wang Y, Ausiello DA, Cantiello HF. Actin filament organization is required for proper cAMP-dependent activation of CFTR. Am J Physiol 1999; 277:C1160-9. [PMID: 10600767 DOI: 10.1152/ajpcell.1999.277.6.c1160] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies have indicated a role of the actin cytoskeleton in the regulation of the cystic fibrosis transmembrane conductance regulator (CFTR) ion channel. However, the exact molecular nature of this regulation is still largely unknown. In this report human epithelial CFTR was expressed in human melanoma cells genetically devoid of the filamin homologue actin-cross-linking protein ABP-280 [ABP(-)]. cAMP stimulation of ABP(-) cells or cells genetically rescued with ABP-280 cDNA [ABP(+)] was without effect on whole cell Cl(-) currents. In ABP(-) cells expressing CFTR, cAMP was also without effect on Cl(-) conductance. In contrast, cAMP induced a 10-fold increase in the diphenylamine-2-carboxylate (DPC)-sensitive whole cell Cl(-) currents of ABP(+)/CFTR(+) cells. Further, in cells expressing both CFTR and a truncated form of ABP-280 unable to cross-link actin filaments, cAMP was also without effect on CFTR activation. Dialysis of ABP-280 or filamin through the patch pipette, however, resulted in a DPC-inhibitable increase in the whole cell currents of ABP(-)/CFTR(+) cells. At the single-channel level, protein kinase A plus ATP activated single Cl(-) channels only in excised patches from ABP(+)/CFTR(+) cells. Furthermore, filamin alone also induced Cl(-) channel activity in excised patches of ABP(-)/CFTR(+) cells. The present data indicate that an organized actin cytoskeleton is required for cAMP-dependent activation of CFTR.
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Affiliation(s)
- A G Prat
- Renal Unit, Massachusetts General Hospital East, Charlestown 02129, USA
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40
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Abstract
The aim of this study was to investigate the hepatocellular site of reactive oxygen species generation during acute ethanol metabolism. Reactive oxygen species production was detected using the 2',7'-dichlorofluorescein fluorescence assay and cell injury was determined by lactate dehydrogenase release. Incubation with 1 and 10 mM ethanol increased the production of reactive oxygen species by 72% and 151%, respectively, which was associated with mild decreases in cell viability. Antimycin, a mitochondrial complex III inhibitor, elicited a 17-fold increase in the levels of reactive oxygen species and markedly decreased hepatocyte viability and ATP levels. Ethanol increased reactive oxygen species production and the cytosolic NADH/NAD+ ratio in antimycin-treated cells. Rotenone, a mitochondrial complex I inhibitor that allows electron flow through the flavin mononucleotide (FMN), but prevents electron flow to complex III, significantly increased reactive oxygen species production in untreated cells, but decreased reactive oxygen species production in antimycin plus ethanol-treated cells. Diphenyliodonium, a mitochondrial complex I inhibitor that inhibits electron flow through FMN, attenuated reactive oxygen species generation in all groups. Fructose prevented cytotoxicity in all treatment groups. Though they do not eliminate the participation of other intracellular compartments, these results indicate that the NADH dehydrogenase complex, as well as complex III of mitochondria, are involved in ethanol-related production of reactive oxygen species.
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Affiliation(s)
- S M Bailey
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1016, USA
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41
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Abstract
Hepatic glycogen levels are decreased in rats as a consequence of chronic ethanol consumption. In earlier studies ethanol (36% of total calories consumed) replaced carbohydrate in the ethanol-containing diet, thus leading to the possibility that the decreases in liver glycogen were a result of limited dietary carbohydrate. In the present study, rats were administered ethanol in low-carbohydrate (LC) or high-carbohydrate (HC) diets to determine if lowered dietary carbohydrate contributes to the decrease in glycogen levels associated with ethanol consumption. The glycogen content of isolated hepatocytes was not different between rats fed LC or HC in control or ethanol-containing diets. Lactate and pyruvate were measured to determine the effects of dietary carbohydrate and ethanol on glycolytic activity, and were not significantly altered by changes in the levels of dietary carbohydrate. However, ethanol-containing diets resulted in decreased concentrations of hepatic glycogen, lactate, and pyruvate as compared with controls in both LC and HC diets. These observations demonstrate that decreases in glycogen content and lactate + pyruvate concentrations are due to chronic ethanol consumption rather than a carbohydrate deficiency, when carbohydrate is maintained above 10% of total calories.
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Affiliation(s)
- C G Van Horn
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1016, USA
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42
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Abstract
BACKGROUND Although oxidative stress and deficits in hepatic energy metabolism have been implicated as important factors in the initiation of alcoholic liver disease, their relative contribution to ethanol-induced cell death is not known. The purpose of this study was to examine the effects of chronic ethanol administration on hepatocyte reactive oxygen species (ROS) generation, energy state, and viability, as well as the effect of dietary fat on these parameters. METHODS Male Sprague-Dawley rats were fed liquid diets that provided 36% total calories as ethanol, with fat as either 12% (low fat) or 35% (high fat) of total calories. Pair-fed controls received liquid diets in which maltose-dextrin was substituted for ethanol calories. The fluorescent probe 2',7'-dichlorofluorescin diacetate was used to detect ROS, lactate dehydrogenase leakage was used to assess viability, and ATP levels were used as a measure of the energy state. The effect of chronic ethanol feeding on these parameters was determined by incubating hepatocytes under a 5% oxygen-containing atmosphere or an atmosphere < or = 1% oxygen for 60 min. RESULTS In general, chronic ethanol feeding stimulated ROS production and decreased ATP concentrations, which were associated with decreased viability in hepatocytes isolated from rats fed either high- or low-fat, ethanol-containing diets, compared to the corresponding controls. Incubation under an atmosphere < or = 1% oxygen and/or ethanol (10 mM) augmented these effects in both high- and low-fat control and ethanol-fed hepatocytes. The addition of antimycin to the incubations increased ROS production, decreased ATP concentrations, and accelerated loss of hepatocyte viability. Viability loss under all conditions used in this study was correlated with decreases in cellular ATP. CONCLUSIONS Comparisons of incubations performed under the two oxygenation conditions revealed that viability loss was inversely associated with ROS production, which indicates that ATP loss and not ROS production was a better predictor of loss in cell integrity. This study also demonstrates that the level of dietary fat has only minor effects on generation of ROS and the cellular energy state. In contrast, ethanol consumption had significant effects on generation of ROS, energy state, and hepatocyte viability.
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Affiliation(s)
- S M Bailey
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1016, USA
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Abstract
Hepatocytes from ethanol-fed animals, isolated from either whole liver or the periportal or perivenous regions of the lobule, exhibited an ethanol-related decrease in energy state only when they were oxygen deficient. This was accompanied by an ethanol-related decrease in hepatocyte viability. Both periportal and perivenous hepatocytes from ethanol-fed rats demonstrated increased respiration. The observations reported here are consistent with an ethanol-induced increase in oxygen utilization which could render the perivenous region of the lobule relatively oxygen deficient in the intact liver. This oxygen deficit may cause the decreases in energy state and cell viability associated with chronic ethanol consumption. Ethanol-associated loss in hepatocyte viability appeared to correlate better with a decrease in energy state than with an increase in the products of oxidative stress. An investigation of the association between viability and cellular malondialdehyde levels revealed no effects of chronic ethanol consumption on MDA levels in hepatocytes that demonstrated ethanol-related decreases in cell viability.
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Affiliation(s)
- C C Cunningham
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157-1016, USA.
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45
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Abstract
Although reactive oxygen species (ROS) have been implicated in the etiology of alcohol-induced liver disease, neither their relative contribution to cell death nor the cellular mechanisms mediating their formation are known. The purpose of this study was to test the hypothesis that acute and chronic ethanol exposure enhances the mitochondrial generation of ROS in fresh, isolated hepatocytes. Acute ethanol exposure stimulated ROS production, increased the cellular NADH/NAD+ ratio, and decreased hepatocyte viability slightly, which was prevented by pretreatment with 4-methylpyrazole (4-MP), an inhibitor of alcohol dehydrogenase. Similarly, xylitol, an NADH-generating compound, enhanced hepatocyte ROS production and decreased viability. Incubation with pyruvate, an NADH-oxidizing compound, and cyanamide, an inhibitor of aldehyde dehydrogenase, significantly decreased ROS levels in acute ethanol-treated hepatocytes. Chronic ethanol consumption produced a sixfold increase in hepatocyte ROS production compared with levels measured in controls. Hepatocytes from ethanol-fed rats were less viable compared with controls, e.g., viability was 68% +/- 2% (ethanol) versus 83% +/- 1% (control) after 60 minutes of incubation. Antimycin A increased ROS production and decreased cell viability; however, the toxic effect of antimycin A was more pronounced in ethanol-fed hepatocytes. These results suggest that acute and chronic ethanol exposure exacerbates mitochondrial ROS production, contributing to cell death.
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Affiliation(s)
- S M Bailey
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC, USA
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Procópio DO, da Silva S, Cunningham CC, Mortara RA. Trypanosoma cruzi: effect of protein kinase inhibitors and cytoskeletal protein organization and expression on host cell invasion by amastigotes and metacyclic trypomastigotes. Exp Parasitol 1998; 90:1-13. [PMID: 9709024 DOI: 10.1006/expr.1998.4314] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although trypomastigotes are regarded as the classic infective forms of T. cruzi, amastigotes generated extracellularly or released from infected cells during lysis may circulate and infect other cells. We have compared the infectivity of metacyclic trypomastigotes and extracellular amastigotes toward HeLa and Vero cells and observed that amastigotes were capable of invading both HeLa and Vero cells to a much higher degree than the corresponding metacyclic forms. Second, cell microfilament or microtubule disruption inhibited amastigote but not trypomastigote entry. Third, cells with altered expression in cytoskeletal components (ABP or gelsolin) internalize amastigotes and trypomastigotes with highly contrasting fashion. Fourth, protein kinase inhibitors such as genistein and staurosporine affect the internalization of amastigotes and trypomastigotes in a host-cell-dependent manner. Our results suggest that extracellular amastigotes and metacyclic trypomastigotes utilize mechanisms to invade host cells with particular features for each T. cruzi form and for each host cell. When internalized, both forms associate to lysosomes of HeLa cells.
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Affiliation(s)
- D O Procópio
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, Rua Botucatu, 862, 6th floor, São Paulo, SP, 04023-062, Brazil
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47
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Laine RO, Phaneuf KL, Cunningham CC, Kwiatkowski D, Azuma T, Southwick FS. Gelsolin, a protein that caps the barbed ends and severs actin filaments, enhances the actin-based motility of Listeria monocytogenes in host cells. Infect Immun 1998; 66:3775-82. [PMID: 9673261 PMCID: PMC108414 DOI: 10.1128/iai.66.8.3775-3782.1998] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The actin-based motility of Listeria monocytogenes requires the addition of actin monomers to the barbed or plus ends of actin filaments. Immunofluorescence micrographs have demonstrated that gelsolin, a protein that both caps barbed ends and severs actin filaments, is concentrated directly behind motile bacteria at the junction between the actin filament rocket tail and the bacterium. In contrast, CapG, a protein that strictly caps actin filaments, fails to localize near intracellular Listeria. To explore the effect of increasing concentrations of gelsolin on bacterial motility, NIH 3T3 fibroblasts stably transfected with gelsolin cDNA were infected with Listeria. The C5 cell line containing 2.25 times control levels of gelsolin supported significantly higher velocities of bacterial movement than did control fibroblasts (mean +/- standard error of the mean, 0.09 +/- 0.003 micro(m)/s [n = 176] versus 0.05 +/- 0.003 micro(m)/s [n = 65]). The rate of disassembly of the Listeria-induced actin filament rocket tail was found to be independent of gelsolin content. Therefore, if increases in gelsolin content result in increases in Listeria-induced rocket tail assembly rates, a positive correlation between gelsolin content and tail length would be expected. BODIPY-phalloidin staining of four different stably transfected NIH 3T3 fibroblast cell lines confirmed this expectation (r = 0.92). Rocket tails were significantly longer in cells with a high gelsolin content. Microinjection of gelsolin 1/2 (consisting of the amino-terminal half of native gelsolin) also increased bacterial velocity by more than 2.2 times. Microinjection of CapG had no effect on bacterial movement. Cultured skin fibroblasts derived from gelsolin-null mice were capable of supporting intracellular Listeria motility at velocities comparable to those supported by wild-type skin fibroblasts. These experiments demonstrated that the surface of Listeria contains a polymerization zone that can block the barbed-end-capping activity of both gelsolin and CapG. The ability of Listeria to uncap actin filaments combined with the severing activity of gelsolin can accelerate actin-based motility. However, gelsolin is not absolutely required for the actin-based intracellular movement of Listeria because its function can be replaced by other actin regulatory proteins in gelsolin-null cells, demonstrating the functional redundancy of the actin system.
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Affiliation(s)
- R O Laine
- Division of Infectious Diseases, Department of Medicine, University of Florida College of Medicine, Gainesville, Florida 32610, USA
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Baio DL, Czyz CN, Van Horn CG, Ivester P, Cunningham CC. Effect of chronic ethanol consumption on respiratory and glycolytic activities of rat periportal and perivenous hepatocytes. Arch Biochem Biophys 1998; 350:193-200. [PMID: 9473292 DOI: 10.1006/abbi.1997.0514] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Previous studies (Ivester et al., Arch. Biochem. Biophys. 322, 14-21, 1995) have established that periportal and perivenous hepatocytes isolated from ethanol-fed rats demonstrate lower ATP concentrations than those in control preparations when the cells are maintained at very low oxygen tension. In the present investigation, experiments were implemented with periportal and perivenous hepatocytes to determine the effects of chronic ethanol consumption on cellular respiratory and glycolytic activities, since both contribute to maintenance of the energy state of the liver cell. Both periportal and perivenous hepatocytes from ethanol-fed rats demonstrated significantly increased, rather than decreased, respiratory activity when monitored with oxygen concentrations ranging from 16 to 140 microM. Whole liver hepatocytes from control and ethanol-fed animals demonstrated equivalent oxygen utilization, however. Glycolytic activity, monitored by lactate + pyruvate concentrations obtained after both anaerobic and aerobic incubation protocols, was decreased in both cell types from ethanol-fed animals. The glycogen concentrations in freshly isolated periportal and perivenous hepatocytes were also decreased eight- and sevenfold, respectively, as compared with control preparations. Incubation under anaerobic conditions resulted in almost complete depletion of glycogen in both cell types. These observations suggest the possibility that the decreased energy state observed in hepatocytes from ethanol-fed animals is related to a depression in anaerobic glycolysis due to depletion of the endogenous substrate, glycogen.
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Affiliation(s)
- D L Baio
- Department of Biochemistry, Wake Forest University Medical Center, Winston-Salem, North Carolina 27157-1016, USA
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Liu G, Thomas L, Warren RA, Enns CA, Cunningham CC, Hartwig JH, Thomas G. Cytoskeletal protein ABP-280 directs the intracellular trafficking of furin and modulates proprotein processing in the endocytic pathway. J Cell Biol 1997; 139:1719-33. [PMID: 9412467 PMCID: PMC1424222 DOI: 10.1083/jcb.139.7.1719] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/1997] [Revised: 10/23/1997] [Indexed: 02/05/2023] Open
Abstract
Furin catalyzes the proteolytic maturation of many proproteins within the trans-Golgi network (TGN)/endosomal system. Furin's cytosolic domain (cd) directs both the compartmentalization to and transit between its manifold processing compartments (i.e., TGN/biosynthetic pathway, cell surface, and endosomes). Here we report the identification of the first furin cd sorting protein, ABP-280 (nonmuscle filamin), an actin gelation protein. The furin cd was used as bait in a yeast two-hybrid screen to identify ABP-280 as a furin-binding protein. Binding analyses in vitro and coimmunoprecipitation studies in vivo showed that furin and ABP-280 interact directly and that ABP-280 tethers furin molecules to the cell surface. Quantitative analysis of both ABP-280-deficient and genetically replete cells showed that ABP-280 modulates the rate of internalization of furin but not of the transferrin receptor, a cycling receptor. However, although ABP-280 directs the rate of furin internalization, the efficiency of sorting of the endoprotease from the cell surface to early endosomes is independent of expression of ABP-280. By contrast, efficient sorting of furin from early endosomes to the TGN requires expression of ABP-280. In addition, ABP-280 is also required for the correct localization of late endosomes (dextran bead uptake) and lysosomes (LAMP-1 staining), demonstrating a pleiotropic role for this actin binding protein in the organization of cellular compartments and directing protein traffic. Finally, and consistent with the trafficking studies on furin, we showed that ABP-280 modulates the processing of furin substrates in the endocytic but not the biosynthetic pathways. The novel roles of ABP-280 and the cytoskeleton in the sorting of furin in the TGN/ endosomal system and the formation of proprotein processing compartments are discussed.
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Affiliation(s)
- G Liu
- Vollum Institute, Oregon Health Sciences University, Portland, Oregon 97201, USA
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50
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Flanagan LA, Cunningham CC, Chen J, Prestwich GD, Kosik KS, Janmey PA. The structure of divalent cation-induced aggregates of PIP2 and their alteration by gelsolin and tau. Biophys J 1997; 73:1440-7. [PMID: 9284311 PMCID: PMC1181043 DOI: 10.1016/s0006-3495(97)78176-1] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Phosphatidylinositol bisphosphate (PIP2) serves as a precursor for diacylglycerol and inositol trisphosphate in signal transduction cascades and regulates the activities of several actin binding proteins that influence the organization of the actin cytoskeleton. Molecules of PIP2 form 6-nm diameter micelles in water, but aggregate into larger, multilamellar structures in physiological concentrations of divalent cations. Electron microscopic analysis of these aggregates reveals that they are clusters of striated filaments, suggesting that PIP2 aggregates form stacks of discoid micelles rather than multilamellar vesicles or inverted hexagonal arrays as previously inferred from indirect observations. The distance between striations within the filaments varies from 4.2 to 5.4 nm and the diameter of the filaments depends on the dehydrated ionic radius of the divalent cation, with average diameters of 19, 12, and 10 nm for filaments formed by Mg2+, Ca2+, and Ba2+, respectively. The structure of the divalent cation-induced aggregates can be altered by PIP2 binding proteins. Gelsolin and the microtubule associated protein tau both affect the formation of aggregates, indicating that tau acts as a PIP2 binding protein in a manner similar to gelsolin. In contrast, another PIP2 binding protein, profilin, does not modify the aggregates.
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Affiliation(s)
- L A Flanagan
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
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