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Slone EA, Pope MR, Fleming SD. Phospholipid scramblase 1 is required for β2-glycoprotein I binding in hypoxia and reoxygenation-induced endothelial inflammation. J Leukoc Biol 2015. [PMID: 26216936 DOI: 10.1189/jlb.3a1014-480r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Multiple pathologic conditions, including hemorrhage, tumor angiogenesis, and ischemia-reperfusion events, will result in hypoxia and subsequent reperfusion. Previous studies have analyzed the lipid changes within whole tissues and indicated that ischemia-reperfusion altered tissue and cellular phospholipids. Using an in vitro cell culture model of hypoxia and reoxygenation, we examined the endothelial lipid changes. We hypothesized that phospholipid scramblase 1, a protein that regulates bilayer asymmetry, is involved in altering the phospholipids of endothelial cells during hypoxia, a component of ischemia, leading to β2-glycoprotein I and IgM binding and subsequent lipid-mediated, inflammatory responses. We have completed the first comprehensive study of steady-state phospholipid scramblase 1 mRNA levels, protein expression, and activity under conditions of hypoxia and reoxygenation. Phospholipid scramblase 1 regulates phosphatidylserine exposure in response to oxygen stress, leading to β2-glycoprotein I and IgM binding and lipid-mediated, inflammatory responses.
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Affiliation(s)
| | - Michael R Pope
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - Sherry D Fleming
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
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2
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Schwer CI, Lehane C, Guelzow T, Zenker S, Strosing KM, Spassov S, Erxleben A, Heimrich B, Buerkle H, Humar M. Thiopental inhibits global protein synthesis by repression of eukaryotic elongation factor 2 and protects from hypoxic neuronal cell death. PLoS One 2013; 8:e77258. [PMID: 24167567 PMCID: PMC3805597 DOI: 10.1371/journal.pone.0077258] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 08/30/2013] [Indexed: 12/27/2022] Open
Abstract
Ischemic and traumatic brain injury is associated with increased risk for death and disability. The inhibition of penumbral tissue damage has been recognized as a target for therapeutic intervention, because cellular injury evolves progressively upon ATP-depletion and loss of ion homeostasis. In patients, thiopental is used to treat refractory intracranial hypertension by reducing intracranial pressure and cerebral metabolic demands; however, therapeutic benefits of thiopental-treatment are controversially discussed. In the present study we identified fundamental neuroprotective molecular mechanisms mediated by thiopental. Here we show that thiopental inhibits global protein synthesis, which preserves the intracellular energy metabolite content in oxygen-deprived human neuronal SK-N-SH cells or primary mouse cortical neurons and thus ameliorates hypoxic cell damage. Sensitivity to hypoxic damage was restored by pharmacologic repression of eukaryotic elongation factor 2 kinase. Translational inhibition was mediated by calcium influx, activation of the AMP-activated protein kinase, and inhibitory phosphorylation of eukaryotic elongation factor 2. Our results explain the reduction of cerebral metabolic demands during thiopental treatment. Cycloheximide also protected neurons from hypoxic cell death, indicating that translational inhibitors may generally reduce secondary brain injury. In conclusion our study demonstrates that therapeutic inhibition of global protein synthesis protects neurons from hypoxic damage by preserving energy balance in oxygen-deprived cells. Molecular evidence for thiopental-mediated neuroprotection favours a positive clinical evaluation of barbiturate treatment. The chemical structure of thiopental could represent a pharmacologically relevant scaffold for the development of new organ-protective compounds to ameliorate tissue damage when oxygen availability is limited.
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Affiliation(s)
- Christian I. Schwer
- Department of Anesthesiology and Critical Care Medicine, University Medical Center Freiburg, Freiburg, Germany
| | - Cornelius Lehane
- Department of Anesthesiology and Critical Care Medicine, University Medical Center Freiburg, Freiburg, Germany
| | - Timo Guelzow
- Department of General Neurosurgery, Cellular Neurophysiology, University Medical Center Freiburg, Freiburg, Germany
| | - Simone Zenker
- Department of Anatomy and Cell Biology, University of Freiburg, Freiburg, Germany
| | - Karl M. Strosing
- Department of Anesthesiology and Critical Care Medicine, University Medical Center Freiburg, Freiburg, Germany
| | - Sashko Spassov
- Department of Anesthesiology and Critical Care Medicine, University Medical Center Freiburg, Freiburg, Germany
| | - Anika Erxleben
- Pharmaceutical Bioinformatics, Institute of Pharmaceutical Sciences, University of Freiburg, Freiburg, Germany
| | - Bernd Heimrich
- Department of Anatomy and Cell Biology, University of Freiburg, Freiburg, Germany
| | - Hartmut Buerkle
- Department of Anesthesiology and Critical Care Medicine, University Medical Center Freiburg, Freiburg, Germany
| | - Matjaz Humar
- Department of Anesthesiology and Critical Care Medicine, University Medical Center Freiburg, Freiburg, Germany
- * E-mail:
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Lehane C, Guelzow T, Zenker S, Erxleben A, Schwer CI, Heimrich B, Buerkle H, Humar M. Carbimazole is an inhibitor of protein synthesis and protects from neuronal hypoxic damage in vitro. J Pharmacol Exp Ther 2013; 347:781-93. [PMID: 24049063 DOI: 10.1124/jpet.113.205989] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Oxygen deprivation during ischemic or hemorrhagic stroke results in ATP depletion, loss of ion homeostasis, membrane depolarization, and excitotoxicity. Pharmacologic restoration of cellular energy supply may offer a promising concept to reduce hypoxic cell injury. In this study, we investigated whether carbimazole, a thionamide used to treat hyperthyroidism, reduces neuronal cell damage in oxygen-deprived human SK-N-SH cells or primary cortical neurons. Our results revealed that carbimazole induces an inhibitory phosphorylation of eukaryotic elongation factor 2 (eEF2) that was associated with a marked inhibition of global protein synthesis. Translational inhibition resulted in significant bioenergetic savings, preserving intracellular ATP content in oxygen-deprived neuronal cells and diminishing hypoxic cellular damage. Phosphorylation of eEF2 was mediated by AMP-activated protein kinase and eEF2 kinase. Carbimazole also induced a moderate calcium influx and a transient cAMP increase. To test whether translational inhibition generally diminishes hypoxic cell damage when ATP availability is limiting, the translational repressors cycloheximide and anisomycin were used. Cycloheximide and anisomycin also preserved ATP content in hypoxic SK-N-SH cells and significantly reduced hypoxic neuronal cell damage. Taken together, these data support a causal relation between the pharmacologic inhibition of global protein synthesis and efficient protection of neurons from ischemic damage by preservation of high-energy metabolites in oxygen-deprived cells. Furthermore, our results indicate that carbimazole or other translational inhibitors may be interesting candidates for the development of new organ-protective compounds. Their chemical structure may be used for computer-assisted drug design or screening of compounds to find new agents with the potential to diminish neuronal damage under ATP-limited conditions.
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Affiliation(s)
- Cornelius Lehane
- Department of Anesthesiology and Critical Care Medicine (C.L., C.I.S., H.B., M.H.) and Department of General Neurosurgery, Cellular Neurophysiology (T.G.), University Medical Center Freiburg, Freiburg, Germany; and Department of Anatomy and Cell Biology (S.Z., B.H.) and Pharmaceutical Bioinformatics, Institute of Pharmaceutical Sciences (A.E.), Albert-Ludwigs-University of Freiburg, Freiburg, Germany
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4
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Mechanism of inhibition of mitochondrial ATP synthase by 17β−Estradiol. J Bioenerg Biomembr 2012; 45:261-70. [DOI: 10.1007/s10863-012-9497-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 12/09/2012] [Indexed: 01/11/2023]
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5
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Mukhopadhyay P, Rajesh M, Horváth B, Bátkai S, Park O, Tanashian G, Gao RY, Patel V, Wink DA, Liaudet L, Haskó G, Mechoulam R, Pacher P. Cannabidiol protects against hepatic ischemia/reperfusion injury by attenuating inflammatory signaling and response, oxidative/nitrative stress, and cell death. Free Radic Biol Med 2011; 50:1368-81. [PMID: 21362471 PMCID: PMC3081988 DOI: 10.1016/j.freeradbiomed.2011.02.021] [Citation(s) in RCA: 144] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Revised: 02/07/2011] [Accepted: 02/19/2011] [Indexed: 02/06/2023]
Abstract
Ischemia/reperfusion (I/R) is a pivotal mechanism of liver damage after liver transplantation or hepatic surgery. We have investigated the effects of cannabidiol (CBD), the nonpsychotropic constituent of marijuana, in a mouse model of hepatic I/R injury. I/R triggered time-dependent increases/changes in markers of liver injury (serum transaminases), hepatic oxidative/nitrative stress (4-hydroxy-2-nonenal, nitrotyrosine content/staining, and gp91phox and inducible nitric oxide synthase mRNA), mitochondrial dysfunction (decreased complex I activity), inflammation (tumor necrosis factor α (TNF-α), cyclooxygenase 2, macrophage inflammatory protein-1α/2, intercellular adhesion molecule 1 mRNA levels; tissue neutrophil infiltration; nuclear factor κB (NF-κB) activation), stress signaling (p38MAPK and JNK), and cell death (DNA fragmentation, PARP activity, and TUNEL). CBD significantly reduced the extent of liver inflammation, oxidative/nitrative stress, and cell death and also attenuated the bacterial endotoxin-triggered NF-κB activation and TNF-α production in isolated Kupffer cells, likewise the adhesion molecule expression in primary human liver sinusoidal endothelial cells stimulated with TNF-α and attachment of human neutrophils to the activated endothelium. These protective effects were preserved in CB2 knockout mice and were not prevented by CB1/2 antagonists in vitro. Thus, CBD may represent a novel, protective strategy against I/R injury by attenuating key inflammatory pathways and oxidative/nitrative tissue injury, independent of classical CB1/2 receptors.
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Affiliation(s)
- Partha Mukhopadhyay
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
| | - Mohanraj Rajesh
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
| | - Béla Horváth
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
| | - Sándor Bátkai
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
| | - Ogyi Park
- Laboratory of Liver Diseases, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
| | - Galin Tanashian
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
| | - Rachel Y Gao
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
| | - Vivek Patel
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
| | - David A. Wink
- Radiation Biology Branch, NCI, National Institutes of Health, Bethesda, Maryland, USA
| | - Lucas Liaudet
- Department of Intensive Care Medicine, University Hospital, Lausanne, Switzerland
| | - György Haskó
- Department of Surgery, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark, New Jersey 07103, USA
| | - Raphael Mechoulam
- Department for Medicinal Chemistry and Natural Products, Faculty of Medicine, Hebrew University of Jerusalem, Ein Kerem, Jerusalem, Israel
| | - Pál Pacher
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, USA
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6
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Wu PY, Lai B, Dong Y, Wang ZM, Li ZC, Zheng P. Different oxidants and PKC isozymes mediate the opposite effect of inhibition of Qi and Qo site of mitochondrial complex III on calcium currents in rat cortical neurons. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1803:1072-82. [DOI: 10.1016/j.bbamcr.2010.05.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 04/29/2010] [Accepted: 05/03/2010] [Indexed: 10/19/2022]
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7
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Gao X, Campian JL, Qian M, Sun XF, Eaton JW. Mitochondrial DNA damage in iron overload. J Biol Chem 2008; 284:4767-75. [PMID: 19095657 DOI: 10.1074/jbc.m806235200] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Chronic iron overload has slow and insidious effects on heart, liver, and other organs. Because iron-driven oxidation of most biologic materials (such as lipids and proteins) is readily repaired, this slow progression of organ damage implies some kind of biological "memory." We hypothesized that cumulative iron-catalyzed oxidant damage to mtDNA might occur in iron overload, perhaps explaining the often lethal cardiac dysfunction. Real time PCR was used to examine the "intactness" of mttDNA in cultured H9c2 rat cardiac myocytes. After 3-5 days exposure to high iron, these cells exhibited damage to mtDNA reflected by diminished amounts of near full-length 15.9-kb PCR product with no change in the amounts of a 16.1-kb product from a nuclear gene. With the loss of intact mtDNA, cellular respiration declined and mRNAs for three electron transport chain subunits and 16 S rRNA encoded by mtDNA decreased, whereas no decrements were found in four subunits encoded by nuclear DNA. To examine the importance of the interactions of iron with metabolically generated reactive oxygen species, we compared the toxic effects of iron in wild-type and rho(o) cells. In wild-type cells, elevated iron caused increased production of reactive oxygen species, cytostasis, and cell death, whereas the rho(o) cells were unaffected. We conclude that long-term damage to cells and organs in iron-overload disorders involves interactions between iron and mitochondrial reactive oxygen species resulting in cumulative damage to mtDNA, impaired synthesis of respiratory chain subunits, and respiratory dysfunction.
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Affiliation(s)
- Xueshan Gao
- Department of Oncology, University of Linköping, Linköping 58185, Sweden
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8
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Li LY, Zhao XL, Fei XF, Gu ZL, Qin ZH, Liang ZQ. Bilobalide inhibits 6-OHDA-induced activation of NF-kappaB and loss of dopaminergic neurons in rat substantia nigra. Acta Pharmacol Sin 2008; 29:539-47. [PMID: 18430361 DOI: 10.1111/j.1745-7254.2008.00787.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
AIM To investigate the effects of bilobalide on the activation of NF-kappaB, and apoptosis of dopaminergic neurons induced by 6-hydroxydopamine (6-OHDA). METHODS A rat model of Parkinson's disease was produced with a unilateral infusion of 6-OHDA (8 mug) into the substantia nigra par compact. Bilobalide was administered 5, 10, and 20 mg/kg (ip) once a day for 7 d, starting 6 d prior to the 6- OHDA infusion. The rats were subjected to locomotor activity and rotational behavior testing 2 or 3 weeks after the 6-OHDA infusion. The expressions of tyrosine hydroxylase (TH) and NF-kappaB p65 were examined by immunofluorescence. The loss of dopaminergic neurons was detected by Nissl's staining. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling was used to identify apoptosis. RESULTS The behavioral changes due to 6-OHDA were significantly restored by bilobalide pretreatment. Bilobalide inhibited the 6-OHDA-induced loss of TH-positive neurons, decreased the activation of NF-kappaB, and protected dopaminergic neurons from apoptosis remarkably. CONCLUSION NF-kappaB activation contributes to the 6-OHDA-induced loss of dopaminergic neurons, and the inhibition of the NF-kappaB pathway is likely to be involved in the neuroprotective effect of bilobalide.
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Affiliation(s)
- Ling-Yun Li
- Department of Pharmacology, Soochow University School of Medicine, Laboratory of Aging and Nervous Diseases, Soochow University School of Medicine, Suzhou 215123, China
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9
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Cario-Toumaniantz C, Boularan C, Schurgers LJ, Heymann MF, Le Cunff M, Léger J, Loirand G, Pacaud P. Identification of differentially expressed genes in human varicose veins: involvement of matrix gla protein in extracellular matrix remodeling. J Vasc Res 2007; 44:444-59. [PMID: 17643059 DOI: 10.1159/000106189] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2007] [Accepted: 05/07/2007] [Indexed: 01/07/2023] Open
Abstract
This study was designed to identify the global pattern of differentially expressed genes in human varicose veins. Using suppressive subtractive hybridization, we identified overexpression of genes known to be associated with extracellular matrix remodeling, including collagen III, tissue inhibitor of metalloproteinases I, dermatopontin, matrix Gla protein (MGP) and tenascin C. Real-time polymerase chain reaction analysis confirmed the differential expression of these genes. The overexpression of MGP transcript was associated with increased MGP level in varicose veins, in particular the undercarboxylated form of the protein. Smooth muscle cells from varicose veins showed increased proliferation rate and enhanced matrix mineralization. This observation correlated with the presence of ectopic mineralization areas in the varicose vein walls. The use of warfarin, to inhibit MGP activity, or siRNA targeting MGP transcript induced a reduction in the exacerbated proliferation of varicose vein smooth muscle cells. Our results suggest that high expression of MGP in varicose veins may contribute to venous wall remodeling by affecting proliferation and mineralization processes probably through impaired carboxylation of MGP. In addition, suppressive subtractive hybridization results also produce a profile of differentially expressed genes in varicose veins, in particular extracellular matrix components. Further study of these genes will provide insights into their specific roles in the etiology of venous disease.
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Calcinosis/genetics
- Calcinosis/metabolism
- Calcinosis/pathology
- Calcium-Binding Proteins/antagonists & inhibitors
- Calcium-Binding Proteins/genetics
- Calcium-Binding Proteins/metabolism
- Case-Control Studies
- Cell Proliferation
- Cells, Cultured
- Dose-Response Relationship, Drug
- Extracellular Matrix/metabolism
- Extracellular Matrix Proteins/antagonists & inhibitors
- Extracellular Matrix Proteins/genetics
- Extracellular Matrix Proteins/metabolism
- Gene Expression Profiling/methods
- Gene Expression Regulation
- Glycerophosphates/metabolism
- Humans
- Male
- Middle Aged
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Oligonucleotide Array Sequence Analysis
- Protein Processing, Post-Translational
- RNA Interference
- RNA, Messenger/metabolism
- RNA, Small Interfering/metabolism
- Reproducibility of Results
- Reverse Transcriptase Polymerase Chain Reaction
- Saphenous Vein/metabolism
- Up-Regulation
- Varicose Veins/genetics
- Varicose Veins/metabolism
- Varicose Veins/pathology
- Warfarin/pharmacology
- Matrix Gla Protein
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10
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Chen JQ, Yager JD, Russo J. Regulation of mitochondrial respiratory chain structure and function by estrogens/estrogen receptors and potential physiological/pathophysiological implications. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2005; 1746:1-17. [PMID: 16169101 DOI: 10.1016/j.bbamcr.2005.08.001] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2005] [Revised: 08/03/2005] [Accepted: 08/03/2005] [Indexed: 01/11/2023]
Abstract
It is well known that the biological and carcinogenic effects of 17beta-estradiol (E2) are mediated via nuclear estrogen receptors (ERs) by regulating nuclear gene expression. Several rapid, non-nuclear genomic effects of E2 are mediated via plasma membrane-bound ERs. In addition, there is accumulating evidence suggesting that mitochondria are also important targets for the action of estrogens and ERs. This review summarized the studies on the effects of estrogens via ERs on mitochondrial structure and function. The potential physiological and pathophysiological implications of deficiency and/or overabundance of these E2/ER-mediated mitochondrial effects in stimulation of cell proliferation, inhibition of apoptosis, E2-mediated cardiovascular and neuroprotective effects in target cells are also discussed.
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Affiliation(s)
- Jin-Qiang Chen
- Breast Cancer Research Laboratory, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111, USA.
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11
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Billottet L, Martel S, Culcasi M, Drieu K, Carrupt PA, Pietri S. Influence of lipophilicity and stereochemistry at the C7 position on the cardioprotective and antioxidant effect of ginkgolides during rat heart ischemia and reperfusion. Drug Dev Res 2005. [DOI: 10.1002/ddr.10424] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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12
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Siqueira IR, Cimarosti H, Fochesatto C, Nunes DS, Salbego C, Elisabetsky E, Netto CA. Neuroprotective effects of Ptychopetalum olacoides Bentham (Olacaceae) on oxygen and glucose deprivation induced damage in rat hippocampal slices. Life Sci 2004; 75:1897-906. [PMID: 15302233 DOI: 10.1016/j.lfs.2004.06.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2004] [Accepted: 06/03/2004] [Indexed: 11/24/2022]
Abstract
Alcoholic infusions of Ptychopetalum olacoides Bentham (PO, Olacaceae) are used in traditional medicine by patients presenting age associated symptoms and those recovering from stroke. The aim of this study is to evaluate the neuroprotective properties of PO ethanol extract (POEE) using hippocampal slices from Wistar rats exposed to oxygen and glucose deprivation (OGD, followed by reoxygenation). Mitochondrial activity, an index of cell viability, was assessed by the MTT assay; in addition, the free radicals content was estimated by the use of dichlorofluorescein diacetate as probe. The OGD ischemic condition significantly impaired cellular viability, and increased free radicals generation. In non-OGD slices, incubation with POEE (0.6 microg/ml) increased (approximately 40%) mitochondrial activity, without affecting free radicals levels. In comparison to OGD controls, slices incubated with POEE (0.6 microg/ml) during and after OGD exposure had significantly increased cellular viability. In addition, at this same concentration, POEE prevented the increase of free radicals content induced by OGD. In view of the fact that respiratory chain inhibition and increased generation of free radicals are major consequences of the ischemic injury, this study suggests that Ptychopetalum olacoides contains useful neuroprotective compounds and, therefore, deserves further scrutiny.
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Affiliation(s)
- Ionara R Siqueira
- Departamento de Bioquímica Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
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13
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Abstract
Obstructive sleep apnoea syndrome (OSA) is associated with increased cardiovascular morbidity and mortality. However, the underlying mechanisms are not entirely understood. This review will summarize the evidence that substantiates the notion that the repeated apnoea-related hypoxic events in OSA, similarly to hypoxia/reperfusion injury, initiate oxidative stress. Thus, affecting energy metabolism, redox-sensitive gene expression, and expression of adhesion molecules. A limited number of studies substantiate this hypothesis directly by demonstrating increased free radical production in OSA leukocytes and increased plasma-lipid peroxidation. A great number of studies, however, support this hypothesis indirectly. Increase in circulating levels of adenosine and urinary uric acid in OSA are implicated with increased production of reactive oxygen species (ROS). Activation of redox-sensitive gene expression is suggested by the increase in some protein products of these genes, including VEGF, erythropoietin, endothelin-1, inflammatory cytokines and adhesion molecules. These implicate the participation of redox-sensitive transcription factors as HIF-1 AP-1 and NFkappaB. Finally, adhesion molecule-dependent increased avidity of OSA monocytes to endothelial cells, combined with diminished NO bioavailability, lead to exaggerated endothelial cell damage and dysfunction. Cumulatively, these processes may exacerbate atherogenic sequelae in OSA.
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Affiliation(s)
- Lena Lavie
- Anatomy and Cell Biology, Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
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14
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Endothelium and venotropic drugs in chronic venous insufficiency: A review. Phlebology 2002. [DOI: 10.1007/bf02638610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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15
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Michiels C, Remacle J, Bouaziz N. Endothelium and Venotropic Drugs in Chronic Venous Insufficiency: A Review. Phlebology 2002. [DOI: 10.1177/026835550201700314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Objective: To review the literature concerning chronic venous disease of the leg and the mechanisms of action of venotropic drugs. Methods: The authors identified relevant papers from their own collection and from medical literature databases. Synthesis: Endothelial cell activation caused by ex-posure to the hypoxic conditions that develop during blood stasis in chronic venous insufficiency patients is proposed to be one factor initiating a pro-inflammatory process in the leg veins. Recruited and activated neutrophils would then be responsible for alterations of the venous wall, typical of what is observed in varicose veins. Venotropic drugs used in the treatment of chronic venous insufficiency patients have long been known to decrease vascular permeability and increase venous tone. Recently, it has been shown that they are also able to prevent endothelial cell activation by hypoxia and a precise biochemical target common to all of them has been identified: the mitochondrial respiratory chain. Conclusion: The influence of venotropic drugs on the mitochondrial respiratory chain provides a rational explanation for the therapeutic benefit to patients of this class of drugs.
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Affiliation(s)
- C. Michiels
- Laboratoire de Biochimie et Biologie cellulaire, University of Namur, Namur, Belgium
| | - J. Remacle
- Laboratoire de Biochimie et Biologie cellulaire, University of Namur, Namur, Belgium
| | - N. Bouaziz
- Laboratoire de Biochimie et Biologie cellulaire, University of Namur, Namur, Belgium
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16
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Abstract
In vivo studies have indicated that systemically administered bilobalide, a sesquiterpene trilactone constituent of Ginkgo biloba leaf extracts, can reduce cerebral edema produced by triethyltin, decrease cortical infarct volume in certain stroke models, and reduce cerebral ischemia. In vitro and ex vivo studies indicate that bilobalide has multiple mechanisms of action that may be associated with neuroprotection, including its preservation of mitochondrial ATP synthesis, its inhibition of apoptotic damage induced by staurosporine or by serum-free medium, its suppression of hypoxia-induced membrane deterioration in the brain, and its actions of increasing the expression of the mitochondrial DNA-encoded COX III subunit of cytochrome c oxidase and the ND1 subunit of NADH dehydrogenase. As multiple modes of action may apply to bilobalide, it could be useful in developing therapy for disorders involving cerebral ischemia and neurodegeneration.
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Affiliation(s)
- Francis V Defeudis
- Institute for BioScience, 153 West Main Street, Westboro, MA 01581, USA.
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