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Rossmann C, Nusshold C, Paar M, Ledinski G, Tafeit E, Koestenberger M, Bernhart EM, Sattler W, Cvirn G, Hallström S. Ethyl pyruvate inhibits oxidation of LDL in vitro and attenuates oxLDL toxicity in EA.hy926 cells. PLoS One 2018; 13:e0191477. [PMID: 29370236 PMCID: PMC5784938 DOI: 10.1371/journal.pone.0191477] [Citation(s) in RCA: 7] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 01/06/2018] [Indexed: 12/29/2022] Open
Abstract
Background Ethyl pyruvate (EP) exerts anti-inflammatory and anti-oxidative properties. The aim of our study was to investigate whether EP is capable of inhibiting the oxidation of LDL, a crucial step in atherogenesis. Additionally, we examined whether EP attenuates the cytotoxic effects of highly oxidized LDL in the human vascular endothelial cell line EA.hy926. Methods Native LDL (nLDL) was oxidized using Cu2+ ions in the presence of increasing amounts of EP. The degree of LDL oxidation was quantified by measuring lipid hydroperoxide (LPO) and malondialdehyde (MDA) concentrations, relative electrophoretic mobilities (REMs), and oxidation-specific immune epitopes. The cytotoxicity of these oxLDLs on EA.hy926 cells was assessed by measuring cell viability and superoxide levels. Furthermore, the cytotoxicity of highly oxidized LDL on EA.hy926 cells under increasing concentrations of EP in the media was assessed including measurements of high energy phosphates (ATP). Results Oxidation of nLDL using Cu2+ ions was remarkably inhibited by EP in a concentration-dependent manner, reflected by decreased levels of LPO, MDA, REM, oxidation-specific epitopes, and diminished cytotoxicity of the obtained oxLDLs in EA.hy926 cells. Furthermore, the cytotoxicity of highly oxidized LDL on EA.hy926 cells was remarkably attenuated by EP added to the media in a concentration-dependent manner reflected by a decrease in superoxide and an increase in viability and ATP levels. Conclusions EP has the potential for an anti-atherosclerotic drug by attenuating both, the oxidation of LDL and the cytotoxic effect of (already formed) oxLDL in EA.hy926 cells. Chronic administration of EP might be beneficial to impede the development of atherosclerotic lesions.
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Affiliation(s)
- Christine Rossmann
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
| | - Christoph Nusshold
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
| | - Margret Paar
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
| | - Gerhard Ledinski
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
| | - Erwin Tafeit
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
| | | | - Eva Maria Bernhart
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Wolfgang Sattler
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Gerhard Cvirn
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
- * E-mail:
| | - Seth Hallström
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
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2
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Bernhart E, Kogelnik N, Prasch J, Gottschalk B, Goeritzer M, Depaoli MR, Reicher H, Nusshold C, Plastira I, Hammer A, Fauler G, Malli R, Graier WF, Malle E, Sattler W. 2-Chlorohexadecanoic acid induces ER stress and mitochondrial dysfunction in brain microvascular endothelial cells. Redox Biol 2018; 15:441-451. [PMID: 29413957 PMCID: PMC5975063 DOI: 10.1016/j.redox.2018.01.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 12/29/2017] [Accepted: 01/04/2018] [Indexed: 02/06/2023] Open
Abstract
Peripheral leukocytes induce blood-brain barrier (BBB) dysfunction through the release of cytotoxic mediators. These include hypochlorous acid (HOCl) that is formed via the myeloperoxidase-H2O2-chloride system of activated phagocytes. HOCl targets the endogenous pool of ether phospholipids (plasmalogens) generating chlorinated inflammatory mediators like e.g. 2-chlorohexadecanal and its conversion product 2-chlorohexadecanoic acid (2-ClHA). In the cerebrovasculature these compounds inflict damage to brain microvascular endothelial cells (BMVEC) that form the morphological basis of the BBB. To follow subcellular trafficking of 2-ClHA we synthesized a ‘clickable’ alkyne derivative (2-ClHyA) that phenocopied the biological activity of the parent compound. Confocal and superresolution structured illumination microscopy revealed accumulation of 2-ClHyA in the endoplasmic reticulum (ER) and mitochondria of human BMVEC (hCMEC/D3 cell line). 2-ClHA and its alkyne analogue interfered with protein palmitoylation, induced ER-stress markers, reduced the ER ATP content, and activated transcription and secretion of interleukin (IL)−6 as well as IL-8. 2-ClHA disrupted the mitochondrial membrane potential and induced procaspase-3 and PARP cleavage. The protein kinase R-like ER kinase (PERK) inhibitor GSK2606414 suppressed 2-ClHA-mediated activating transcription factor 4 synthesis and IL-6/8 secretion, but showed no effect on endothelial barrier dysfunction and cleavage of procaspase-3. Our data indicate that 2-ClHA induces potent lipotoxic responses in brain endothelial cells and could have implications in inflammation-induced BBB dysfunction.
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Affiliation(s)
- Eva Bernhart
- Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria.
| | - Nora Kogelnik
- Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria.
| | - Jürgen Prasch
- Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria.
| | - Benjamin Gottschalk
- Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria.
| | - Madeleine Goeritzer
- Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria; BioTechMed Graz, Austria.
| | - Maria Rosa Depaoli
- Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria.
| | - Helga Reicher
- Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria.
| | - Christoph Nusshold
- Institute of Physiological Chemistry, Medical University of Graz, Austria.
| | - Ioanna Plastira
- Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria.
| | - Astrid Hammer
- Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Cell Biology, Histology and Embryology, Medical University of Graz, Austria.
| | - Günter Fauler
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Austria.
| | - Roland Malli
- Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria; BioTechMed Graz, Austria.
| | - Wolfgang F Graier
- Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria; BioTechMed Graz, Austria.
| | - Ernst Malle
- Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria.
| | - Wolfgang Sattler
- Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria; BioTechMed Graz, Austria.
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3
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Paar M, Rossmann C, Nusshold C, Wagner T, Schlagenhauf A, Leschnik B, Oettl K, Koestenberger M, Cvirn G, Hallström S. Anticoagulant action of low, physiologic, and high albumin levels in whole blood. PLoS One 2017; 12:e0182997. [PMID: 28800610 PMCID: PMC5553770 DOI: 10.1371/journal.pone.0182997] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 07/27/2017] [Indexed: 01/01/2023] Open
Abstract
Albumin is the most abundant plasma protein. Critical illness is often associated with altered, predominately decreased, serum albumin levels. This hypoalbuminaemia is usually corrected by administration of exogenous albumin. This study aimed to track the concentration-dependent influence of albumin on blood coagulation in vitro. Whole blood (WB) samples from 25 volunteers were prepared to contain low (19.3 ± 7.7 g/L), physiological (45.2 ± 7.8 g/L), and high (67.5 ± 18.1 g/L) levels of albumin. Haemostatic profiling was performed using a platelet function analyzer (PFA) 200, impedance aggregometry, a Cone and Platelet analyzer (CPA), calibrated automated thrombogram, and thrombelastometry (TEM). Platelet aggregation-associated ATP release was assessed via HPLC analysis. In the low albumin group, when compared to the physiological albumin group, we found: i) shortened PFA 200-derived closure times indicating increased primary haemostasis; ii) increased impedance aggregometry-derived amplitudes, slopes, ATP release, as well as CPA-derived average size indicating improved platelet aggregation; iii) increased TEM-derived maximum clot firmness and alpha angles indicating enhanced clot formation. TEM measurements indicated impaired clot formation in the high albumin group compared with the physiological albumin group. Thus, albumin exerted significant anticoagulant action. Therefore, low albumin levels, often present in cancer or critically ill patients, might contribute to the frequently occurring venous thromboembolism.
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Affiliation(s)
- Margret Paar
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
| | - Christine Rossmann
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
| | - Christoph Nusshold
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
| | - Thomas Wagner
- Department of Blood Group Serology and Transfusion Medicine, Medical University of Graz, Graz, Austria
| | | | - Bettina Leschnik
- Department of Pediatrics, Medical University of Graz, Graz, Austria
| | - Karl Oettl
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
| | | | - Gerhard Cvirn
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
- * E-mail:
| | - Seth Hallström
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
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4
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Radulović S, Kirsch A, Schilcher I, Lechleitner M, Nusshold C, Hallström S, Frank S. The capacity of el modified serum/Apo B depleted serum to protect vascular endothelial function. Atherosclerosis 2016. [DOI: 10.1016/j.atherosclerosis.2016.07.776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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5
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Nusshold C, Üllen A, Kogelnik N, Bernhart E, Reicher H, Plastira I, Glasnov T, Zangger K, Rechberger G, Kollroser M, Fauler G, Wolinski H, Weksler BB, Romero IA, Kohlwein SD, Couraud PO, Malle E, Sattler W. Assessment of electrophile damage in a human brain endothelial cell line utilizing a clickable alkyne analog of 2-chlorohexadecanal. Free Radic Biol Med 2016; 90:59-74. [PMID: 26577177 PMCID: PMC6392177 DOI: 10.1016/j.freeradbiomed.2015.11.010] [Citation(s) in RCA: 12] [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: 08/11/2015] [Revised: 11/05/2015] [Accepted: 11/07/2015] [Indexed: 11/19/2022]
Abstract
Peripheral leukocytes aggravate brain damage by releasing cytotoxic mediators that compromise blood-brain barrier function. One of the oxidants released by activated leukocytes is hypochlorous acid (HOCl) that is formed via the myeloperoxidase-H2O2-chloride system. The reaction of HOCl with the endogenous plasmalogen pool of brain endothelial cells results in the generation of 2-chlorohexadecanal (2-ClHDA), a toxic, lipid-derived electrophile that induces blood-brain barrier dysfunction in vivo. Here, we synthesized an alkynyl-analog of 2-ClHDA, 2-chlorohexadec-15-yn-1-al (2-ClHDyA) to identify potential protein targets in the human brain endothelial cell line hCMEC/D3. Similar to 2-ClHDA, 2-ClHDyA administration reduced cell viability/metabolic activity, induced processing of pro-caspase-3 and PARP, and led to endothelial barrier dysfunction at low micromolar concentrations. Protein-2-ClHDyA adducts were fluorescently labeled with tetramethylrhodamine azide (N3-TAMRA) by 1,3-dipolar cycloaddition in situ, which unveiled a preferential accumulation of 2-ClHDyA adducts in mitochondria, the Golgi, endoplasmic reticulum, and endosomes. Thirty-three proteins that are subject to 2-ClHDyA-modification in hCMEC/D3 cells were identified by mass spectrometry. Identified proteins include cytoskeletal components that are central to tight junction patterning, metabolic enzymes, induction of the oxidative stress response, and electrophile damage to the caveolar/endosomal Rab machinery. A subset of the targets was validated by a combination of N3-TAMRA click chemistry and specific antibodies by fluorescence microscopy. This novel alkyne analog is a valuable chemical tool to identify cellular organelles and protein targets of 2-ClHDA-mediated damage in settings where myeloperoxidase-derived oxidants may play a disease-propagating role.
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Affiliation(s)
- Christoph Nusshold
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria; BioTechMed Graz, Austria
| | - Andreas Üllen
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Nora Kogelnik
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Eva Bernhart
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Helga Reicher
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Ioanna Plastira
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Toma Glasnov
- Christian Doppler Laboratory for Flow Chemistry, Institute of Chemistry, University of Graz, Austria
| | | | - Gerald Rechberger
- BioTechMed Graz, Austria; Institute of Molecular Biosciences, NAWI-Graz, University of Graz, Austria; OMICS-Center Graz, BioTechMed Graz, Austria
| | | | - Günter Fauler
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Austria
| | - Heimo Wolinski
- BioTechMed Graz, Austria; Institute of Molecular Biosciences, NAWI-Graz, University of Graz, Austria
| | - Babette B Weksler
- Weill Medical College of Cornell University, New York, NY 10065, USA
| | - Ignacio A Romero
- Department of Biological Sciences, The Open University, Walton Hall, Milton Keynes MK7 6BJ, UK
| | - Sepp D Kohlwein
- BioTechMed Graz, Austria; Institute of Molecular Biosciences, NAWI-Graz, University of Graz, Austria
| | - Pierre-Olivier Couraud
- Institut Cochin, Inserm, U1016, CNRS UMR 8104, Paris Descartes University, Sorbonne Paris Cité, Paris, France
| | - Ernst Malle
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Wolfgang Sattler
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria; BioTechMed Graz, Austria.
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6
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Bernhart E, Damm S, Wintersperger A, Nusshold C, Brunner AM, Plastira I, Rechberger G, Reicher H, Wadsack C, Zimmer A, Malle E, Sattler W. Interference with distinct steps of sphingolipid synthesis and signaling attenuates proliferation of U87MG glioma cells. Biochem Pharmacol 2015; 96:119-30. [PMID: 26002572 PMCID: PMC4490581 DOI: 10.1016/j.bcp.2015.05.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 05/12/2015] [Indexed: 12/22/2022]
Abstract
Glioblastoma is the most common malignant brain tumor, which, despite combined radio- and chemotherapy, recurs and is invariably fatal for affected patients. Members of the sphingolipid (SL) family are potent effectors of glioma cell proliferation. In particular sphingosine-1-phosphate (S1P) and the corresponding G protein-coupled S1P receptors transmit proliferative signals to glioma cells. To investigate the contribution to glioma cell proliferation we inhibited the first step of de novo SL synthesis in p53wt and p53mut glioma cells, and interfered with S1P signaling specifically in p53wt U87MG cells. Subunit silencing (RNAi) or pharmacological antagonism (using myriocin) of serine palmitoyltransferase (SPT; catalyzing the first committed step of SL biosynthesis) reduced proliferation of p53wt but not p53mut GBM cells. In U87MG cells these observations were accompanied by decreased ceramide, sphingomyelin, and S1P content. Inhibition of SPT upregulated p53 and p21 expression and induced an increase in early and late apoptotic U87MG cells. Exogenously added S1P (complexed to physiological carriers) increased U87MG proliferation. In line, silencing of individual members of the S1P receptor family decreased U87MG proliferation. Silencing and pharmacological inhibition of the ATP-dependent cassette transporter A1 (ABCA1) that facilitates S1P efflux in astrocytes attenuated U87MG growth. Glyburide-mediated inhibition of ABCA1 resulted in intracellular accumulation of S1P raising the possibility that ABCA1 promotes S1P efflux in U87MG glioma cells thereby contributing to inside-out signaling. Our findings indicate that de novo SL synthesis, S1P receptor-mediated signaling, and ABCA1-mediated S1P efflux could provide pharmacological targets to interfere with glioma cell proliferation.
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Affiliation(s)
- Eva Bernhart
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Sabine Damm
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Andrea Wintersperger
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Christoph Nusshold
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria; BioTechMed Graz, Austria
| | - Anna Martina Brunner
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Ioanna Plastira
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | | | - Helga Reicher
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Christian Wadsack
- Department of Obstetrics and Gynecology, Medical University of Graz, Austria
| | - Andreas Zimmer
- BioTechMed Graz, Austria; Institute of Pharmaceutical Sciences, Department of Pharmaceutical Technology, University of Graz, Austria
| | - Ernst Malle
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Wolfgang Sattler
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria; BioTechMed Graz, Austria.
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7
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Üllen A, Nusshold C, Glasnov T, Saf R, Cantillo D, Eibinger G, Reicher H, Fauler G, Bernhart E, Hallstrom S, Kogelnik N, Zangger K, Oliver Kappe C, Malle E, Sattler W. Covalent adduct formation between the plasmalogen-derived modification product 2-chlorohexadecanal and phloretin. Biochem Pharmacol 2015; 93:470-81. [PMID: 25576489 PMCID: PMC4321883 DOI: 10.1016/j.bcp.2014.12.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 12/23/2014] [Accepted: 12/24/2014] [Indexed: 12/02/2022]
Abstract
Hypochlorous acid added as reagent or generated by the myeloperoxidase (MPO)-H2O2-Cl− system oxidatively modifies brain ether-phospholipids (plasmalogens). This reaction generates a sn2-acyl-lysophospholipid and chlorinated fatty aldehydes. 2-Chlorohexadecanal (2-ClHDA), a prototypic member of chlorinated long-chain fatty aldehydes, has potent neurotoxic potential by inflicting blood–brain barrier (BBB) damage. During earlier studies we could show that the dihydrochalcone-type polyphenol phloretin attenuated 2-ClHDA-induced BBB dysfunction. To clarify the underlying mechanism(s) we now investigated the possibility of covalent adduct formation between 2-ClHDA and phloretin. Coincubation of 2-ClHDA and phloretin in phosphatidylcholine liposomes revealed a half-life of 2-ClHDA of approx. 120 min, decaying at a rate of 5.9 × 10−3 min−1. NMR studies and enthalpy calculations suggested that 2-ClHDA-phloretin adduct formation occurs via electrophilic aromatic substitution followed by hemiacetal formation on the A-ring of phloretin. Adduct characterization by high-resolution mass spectroscopy confirmed these results. In contrast to 2-ClHDA, the covalent 2-ClHDA-phloretin adduct was without adverse effects on MTT reduction (an indicator for metabolic activity), cellular adenine nucleotide content, and barrier function of brain microvascular endothelial cells (BMVEC). Of note, 2-ClHDA-phloretin adduct formation was also observed in BMVEC cultures. Intraperitoneal application and subsequent GC–MS analysis of brain lipid extracts revealed that phloretin is able to penetrate the BBB of C57BL/6J mice. Data of the present study indicate that phloretin scavenges 2-ClHDA, thereby attenuating 2-ClHDA-mediated brain endothelial cell dysfunction. We here identify a detoxification pathway for a prototypic chlorinated fatty aldehyde (generated via the MPO axis) that compromises BBB function in vitro and in vivo.
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Affiliation(s)
- Andreas Üllen
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Christoph Nusshold
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Toma Glasnov
- Christian Doppler Laboratory for Flow Chemistry, Institute of Chemistry, University of Graz, Graz, Austria
| | - Robert Saf
- Institute of Chemistry and Technology of Materials, Graz University of Technology, Graz, Austria
| | - David Cantillo
- Institute of Chemistry, University of Graz, Graz, Austria
| | - Gerald Eibinger
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Helga Reicher
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Günter Fauler
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
| | - Eva Bernhart
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Seth Hallstrom
- Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria
| | - Nora Kogelnik
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Klaus Zangger
- Institute of Chemistry, University of Graz, Graz, Austria
| | - C Oliver Kappe
- Institute of Chemistry, University of Graz, Graz, Austria
| | - Ernst Malle
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Wolfgang Sattler
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria.
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8
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Nusshold C, Uellen A, Bernhart E, Hammer A, Damm S, Wintersperger A, Reicher H, Hermetter A, Malle E, Sattler W. Endocytosis and intracellular processing of BODIPY-sphingomyelin by murine CATH.a neurons. Biochim Biophys Acta 2013; 1831:1665-78. [PMID: 23973266 PMCID: PMC3807659 DOI: 10.1016/j.bbalip.2013.08.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 08/01/2013] [Accepted: 08/06/2013] [Indexed: 01/24/2023]
Abstract
Neuronal sphingolipids (SL) play important roles during axonal extension, neurotrophic receptor signaling and neurotransmitter release. Many of these signaling pathways depend on the presence of specialized membrane microdomains termed lipid rafts. Sphingomyelin (SM), one of the main raft constituents, can be formed de novo or supplied from exogenous sources. The present study aimed to characterize fluorescently-labeled SL turnover in a murine neuronal cell line (CATH.a). Our results demonstrate that at 4°C exogenously added BODIPY-SM accumulates exclusively at the plasma membrane. Treatment of cells with bacterial sphingomyelinase (SMase) and back-exchange experiments revealed that 55-67% of BODIPY-SM resides in the outer leaflet of the plasma membrane. Endocytosis of BODIPY-SM occurs via caveolae with part of internalized BODIPY-fluorescence ending up in the Golgi and the ER. Following endocytosis BODIPY-SM undergoes hydrolysis, a reaction substantially faster than BODIPY-SM synthesis from BODIPY-ceramide. RNAi demonstrated that both, acid (a)SMase and neutral (n)SMases contribute to BODIPY-SM hydrolysis. Finally, high-density lipoprotein (HDL)-associated BODIPY-SM was efficiently taken up by CATH.a cells. Our findings indicate that endocytosis of exogenous SM occurs almost exclusively via caveolin-dependent pathways, that both, a- and nSMases equally contribute to neuronal SM turnover and that HDL-like particles might represent physiological SM carriers/donors in the brain.
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Affiliation(s)
- Christoph Nusshold
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Andreas Uellen
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Eva Bernhart
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Astrid Hammer
- Institute of Cell Biology, Histology and Embryology, Medical University of Graz, Graz, Austria
| | - Sabine Damm
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Andrea Wintersperger
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Helga Reicher
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Albin Hermetter
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
| | - Ernst Malle
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Wolfgang Sattler
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
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9
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Üllen A, Singewald E, Konya V, Fauler G, Reicher H, Nusshold C, Hammer A, Kratky D, Heinemann A, Holzer P, Malle E, Sattler W. Myeloperoxidase-derived oxidants induce blood-brain barrier dysfunction in vitro and in vivo. PLoS One 2013; 8:e64034. [PMID: 23691142 PMCID: PMC3653856 DOI: 10.1371/journal.pone.0064034] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [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: 10/31/2012] [Accepted: 04/10/2013] [Indexed: 12/24/2022] Open
Abstract
Peripheral leukocytes can exacerbate brain damage by release of cytotoxic mediators that disrupt blood-brain barrier (BBB) function. One of the oxidants released by activated leukocytes is hypochlorous acid (HOCl) formed via the myeloperoxidase (MPO)-H2O2-Cl(-) system. In the present study we examined the role of leukocyte activation, leukocyte-derived MPO and MPO-generated oxidants on BBB function in vitro and in vivo. In a mouse model of lipopolysaccharide (LPS)-induced systemic inflammation, neutrophils that had become adherent released MPO into the cerebrovasculature. In vivo, LPS-induced BBB dysfunction was significantly lower in MPO-deficient mice as compared to wild-type littermates. Both, fMLP-activated leukocytes and the MPO-H2O2-Cl(-) system inflicted barrier dysfunction of primary brain microvascular endothelial cells (BMVEC) that was partially rescued with the MPO inhibitor 4-aminobenzoic acid hydrazide. BMVEC treatment with the MPO-H2O2-Cl(-) system or activated neutrophils resulted in the formation of plasmalogen-derived chlorinated fatty aldehydes. 2-chlorohexadecanal (2-ClHDA) severely compromised BMVEC barrier function and induced morphological alterations in tight and adherens junctions. In situ perfusion of rat brain with 2-ClHDA increased BBB permeability in vivo. 2-ClHDA potently activated the MAPK cascade at physiological concentrations. An ERK1/2 and JNK antagonist (PD098059 and SP600125, respectively) protected against 2-ClHDA-induced barrier dysfunction in vitro. The current data provide evidence that interference with the MPO pathway could protect against BBB dysfunction under (neuro)inflammatory conditions.
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Affiliation(s)
- Andreas Üllen
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Evelin Singewald
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Austria
| | - Viktoria Konya
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Austria
| | - Günter Fauler
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Austria
| | - Helga Reicher
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Christoph Nusshold
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Astrid Hammer
- Institute of Cell Biology, Histology and Embryology, Medical University of Graz, Austria
| | - Dagmar Kratky
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Akos Heinemann
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Austria
| | - Peter Holzer
- Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Austria
| | - Ernst Malle
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Wolfgang Sattler
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
- * E-mail:
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10
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Doddapattar P, Radović B, Patankar JV, Obrowsky S, Jandl K, Nusshold C, Kolb D, Vujić N, Doshi L, Chandak PG, Goeritzer M, Ahammer H, Hoefler G, Sattler W, Kratky D. Xanthohumol ameliorates atherosclerotic plaque formation, hypercholesterolemia, and hepatic steatosis in ApoE-deficient mice. Mol Nutr Food Res 2013; 57:1718-28. [PMID: 23650230 DOI: 10.1002/mnfr.201200794] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 03/05/2013] [Accepted: 03/13/2013] [Indexed: 01/05/2023]
Abstract
SCOPE Xanthohumol (XN), a prenylated antioxidative and anti-inflammatory chalcone from hops, exhibits positive effects on lipid and glucose metabolism. Based on its favorable biological properties, we investigated whether XN attenuates atherosclerosis in western-type diet-fed apolipoprotein-E-deficient (ApoE⁻/⁻) mice. METHODS AND RESULTS XN supplementation markedly reduced plasma cholesterol concentrations, decreased atherosclerotic lesion area, and attenuated plasma concentrations of the proinflammatory cytokine monocyte chemoattractant protein 1. Decreased hepatic triglyceride and cholesterol content, activation of AMP-activated protein kinase, phosphorylation and inactivation of acetyl-CoA carboxylase, and reduced expression levels of mature sterol regulatory element-binding protein (SREBP)-2 and SREBP-1c mRNA indicate reduced lipogenesis in the liver of XN-fed ApoE⁻/⁻ mice. Concomitant induction of hepatic mRNA expression of carnitine palmitoyltransferase-1a in ApoE⁻/⁻ mice-administered XN suggests increased fatty acid beta-oxidation. Fecal cholesterol concentrations were also markedly increased in XN-fed ApoE⁻/⁻ mice compared with mice fed western-type diet alone. CONCLUSION The atheroprotective effects of XN might be attributed to combined beneficial effects on plasma cholesterol and monocyte chemoattractant protein 1 concentrations and hepatic lipid metabolism via activation of AMP-activated protein kinase.
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Affiliation(s)
- Prakash Doddapattar
- Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Graz, Austria
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11
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Waltl S, Patankar JV, Fauler G, Nusshold C, Ullen A, Eibinger G, Wintersperger A, Kratky D, Malle E, Sattler W. 25-Hydroxycholesterol regulates cholesterol homeostasis in the murine CATH.a neuronal cell line. Neurosci Lett 2013; 539:16-21. [PMID: 23347841 PMCID: PMC3610018 DOI: 10.1016/j.neulet.2013.01.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Revised: 01/03/2013] [Accepted: 01/08/2013] [Indexed: 12/20/2022]
Abstract
Aberrant oxysterol biosynthesis is implicated in the pathogenesis of neurodegenerative diseases. During the present study we have investigated the effects of exogenously added 25-hydroxycholesterol (25-HC) on transcription of cholesterol biosynthetic genes, sterol-regulatory element binding protein (SREBP) processing and cholesterol biosynthesis in the murine CATH.a neuronal cell line. A single i.p. injection of lipopolysaccharide resulted in robust induction of cholesterol 25-hydroxylase mRNA and protein levels in brains of treated mice. In vitro, 25-HC upregulated the transcription of ATP-binding cassette transporter A1 (ABCA1) and (to a lesser extent) apolipoprotein E (apoE) in CATH.a neurons. Cholesterol biosynthetic gene expression (squalene synthase, HMG-CoA synthase, HMG-CoA reductase, and SREBP2) was downregulated by 25-HC. 25-HC also significantly attenuated proteolytic processing of SREBP2. Finally, 25-HC downregulated cholesterol biosynthesis in CATH.a neurons. Our results demonstrate that 25-HC is a potent effector oxysterol of neuronal cholesterol homeostasis.
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Affiliation(s)
- Sabine Waltl
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
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12
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Üllen A, Fauler G, Bernhart E, Nusshold C, Reicher H, Leis HJ, Malle E, Sattler W. Phloretin ameliorates 2-chlorohexadecanal-mediated brain microvascular endothelial cell dysfunction in vitro. Free Radic Biol Med 2012; 53:1770-81. [PMID: 22982051 PMCID: PMC3485557 DOI: 10.1016/j.freeradbiomed.2012.08.575] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 06/11/2012] [Accepted: 08/18/2012] [Indexed: 11/21/2022]
Abstract
2-Chlorohexadecanal (2-ClHDA), a chlorinated fatty aldehyde, is formed via attack on ether-phospholipids by hypochlorous acid (HOCl) that is generated by the myeloperoxidase-hydrogen peroxide-chloride system of activated leukocytes. 2-ClHDA levels are elevated in atherosclerotic lesions, myocardial infarction, and neuroinflammation. Neuroinflammatory conditions are accompanied by accumulation of neutrophils (an ample source of myeloperoxidase) in the brain. Microvessel damage by inflammatory mediators and/or reactive oxidants can induce blood-brain barrier (BBB) dysfunction, a pathological condition leading to cerebral edema, brain hemorrhage, and neuronal death. In this in vitro study we investigated the impact of 2-ClHDA on brain microvascular endothelial cells (BMVEC), which constitute the morphological basis of the BBB. We show that exogenously added 2-ClHDA is subject to rapid uptake and metabolism by BMVEC. Using C16 structural analogues of 2-ClHDA we found that the cytotoxic potential decreases in the following order: 2-ClHDA>hexadecanal>palmitic acid>2-ClHDA-dimethylacetal. 2-ClHDA induces loss of barrier function, mitochondrial dysfunction, apoptosis via activation of caspase 3, and altered intracellular redox balance. Finally we investigated potential protective effects of several natural polyphenols on in vitro BBB function. Of the compounds tested, phloretin almost completely abrogated 2-ClHDA-induced BMVEC barrier dysfunction and cell death. These data suggest that 2-ClHDA has the potential to induce BBB breakdown under inflammatory conditions and that phloretin confers protection in this experimental setting.
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Affiliation(s)
- Andreas Üllen
- Institute of Molecular Biology and Biochemistry, University Children's Hospital, Medical University of Graz, Graz, Austria
| | - Günter Fauler
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, University Children's Hospital, Medical University of Graz, Graz, Austria
| | - Eva Bernhart
- Institute of Molecular Biology and Biochemistry, University Children's Hospital, Medical University of Graz, Graz, Austria
| | - Christoph Nusshold
- Institute of Molecular Biology and Biochemistry, University Children's Hospital, Medical University of Graz, Graz, Austria
| | - Helga Reicher
- Institute of Molecular Biology and Biochemistry, University Children's Hospital, Medical University of Graz, Graz, Austria
| | - Hans-Jörg Leis
- Research Unit of Osteology and Analytical Mass Spectrometry, University Children's Hospital, Medical University of Graz, 8010 Graz, Austria
| | - Ernst Malle
- Institute of Molecular Biology and Biochemistry, University Children's Hospital, Medical University of Graz, Graz, Austria
| | - Wolfgang Sattler
- Institute of Molecular Biology and Biochemistry, University Children's Hospital, Medical University of Graz, Graz, Austria
- Corresponding author. Fax: +43 316 380 9615.
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13
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Damm M, Nusshold C, Cantillo D, Rechberger GN, Gruber K, Sattler W, Kappe CO. Can electromagnetic fields influence the structure and enzymatic digest of proteins? A critical evaluation of microwave-assisted proteomics protocols. J Proteomics 2012; 75:5533-43. [PMID: 22889711 PMCID: PMC3484400 DOI: 10.1016/j.jprot.2012.07.043] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 07/27/2012] [Accepted: 07/27/2012] [Indexed: 10/31/2022]
Abstract
This study reevaluates the putative advantages of microwave-assisted tryptic digests compared to conventionally heated protocols performed at the same temperature. An initial investigation of enzyme stability in a temperature range of 37-80 °C demonstrated that trypsin activity declines sharply at temperatures above 60 °C, regardless if microwave dielectric heating or conventional heating is employed. Tryptic digests of three proteins of different size (bovine serum albumin, cytochrome c and β-casein) were thus performed at 37 °C and 50 °C using both microwave and conventional heating applying accurate internal fiber-optic probe reaction temperature measurements. The impact of the heating method on protein degradation and peptide fragment generation was analyzed by SDS-PAGE and MALDI-TOF-MS. Time-dependent tryptic digestion of the three proteins and subsequent analysis of the corresponding cleavage products by MALDI-TOF provided virtually identical results for both microwave and conventional heating. In addition, the impact of electromagnetic field strength on the tertiary structure of trypsin and BSA was evaluated by molecular mechanics calculations. These simulations revealed that the applied field in a typical laboratory microwave reactor is 3-4 orders of magnitude too low to induce conformational changes in proteins or enzymes.
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Affiliation(s)
- Markus Damm
- Christian Doppler Laboratory for Microwave Chemistry (CDLMC) and Institute of Chemistry, Karl-Franzens-University Graz, Heinrichstrasse 28/I, A-8010 Graz, Austria
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14
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Üllen A, Fauler G, Köfeler H, Waltl S, Nusshold C, Bernhart E, Reicher H, Leis HJ, Wintersperger A, Malle E, Sattler W. Mouse brain plasmalogens are targets for hypochlorous acid-mediated modification in vitro and in vivo. Free Radic Biol Med 2010; 49:1655-65. [PMID: 20807565 PMCID: PMC4061399 DOI: 10.1016/j.freeradbiomed.2010.08.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [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: 06/18/2010] [Revised: 08/02/2010] [Accepted: 08/23/2010] [Indexed: 11/18/2022]
Abstract
Plasmalogens, 1-O-alk-1'-enyl-2-acyl-sn-glycerophospholipids, are significant constituents of cellular membranes and are essential for normal brain development. Plasmalogens, which contain a vinyl ether bond at the sn-1 position, are preferential targets for hypochlorous acid (HOCl), generated by myeloperoxidase (MPO) from H(2)O(2) and chloride ions. Because MPO is implicated in neurodegeneration, this study pursued two aims: (i) to investigate the reactivity of mouse brain plasmalogens toward HOCl in vitro and (ii) to obtain in vivo evidence for MPO-mediated brain plasmalogen modification. Liquid chromatography coupled to hybrid linear ion trap-Fourier transform-ion cyclotron resonance mass spectrometry revealed plasmalogen modification in mouse brain lipid extracts at lower HOCl concentrations as observed for diacylphospholipids, resulting in the generation of 2-chloro fatty aldehydes and lysophospholipids. Lysophosphatidylethanolamine accumulation was transient, whereas lysophosphatidylcholine species containing saturated acyl residues remained stable. In vivo, a single, systemic endotoxin injection resulted in upregulation of cerebral MPO mRNA levels to a range comparable to that observed for tumor necrosis factor-α and cyclooxygenase-2. This inflammatory response was accompanied by a significant decrease in several brain plasmalogen species and concomitant in vivo generation of 2-chlorohexadecanal. The present findings demonstrate that activation of the MPO-H(2)O(2)-chloride system under neuroinflammatory conditions results in oxidative attack of the total cerebral plasmalogen pool. As this lipid class is indispensable for normal neuronal function, HOCl-mediated plasmalogen modification is likely to compromise normal synaptic transmission.
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Affiliation(s)
- Andreas Üllen
- Institute of Molecular Biology and Biochemistry, Center for Molecular Medicine, Medical University of Graz, 8010 Graz, Austria
| | - Günter Fauler
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, 8010 Graz, Austria
| | - Harald Köfeler
- Center of Medical Research, Medical University of Graz, 8010 Graz, Austria
| | - Sabine Waltl
- Institute of Molecular Biology and Biochemistry, Center for Molecular Medicine, Medical University of Graz, 8010 Graz, Austria
| | - Christoph Nusshold
- Institute of Molecular Biology and Biochemistry, Center for Molecular Medicine, Medical University of Graz, 8010 Graz, Austria
| | - Eva Bernhart
- Institute of Molecular Biology and Biochemistry, Center for Molecular Medicine, Medical University of Graz, 8010 Graz, Austria
| | - Helga Reicher
- Institute of Molecular Biology and Biochemistry, Center for Molecular Medicine, Medical University of Graz, 8010 Graz, Austria
| | - Hans-Jörg Leis
- Research Unit of Osteology and Analytical Mass Spectrometry, University Children’s Hospital, Medical University of Graz, 8010 Graz, Austria
| | - Andrea Wintersperger
- Institute of Molecular Biology and Biochemistry, Center for Molecular Medicine, Medical University of Graz, 8010 Graz, Austria
| | - Ernst Malle
- Institute of Molecular Biology and Biochemistry, Center for Molecular Medicine, Medical University of Graz, 8010 Graz, Austria
| | - Wolfgang Sattler
- Institute of Molecular Biology and Biochemistry, Center for Molecular Medicine, Medical University of Graz, 8010 Graz, Austria
- Corresponding author. Fax: +43 316 380 9615.
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15
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Nusshold C, Kollroser M, Köfeler H, Rechberger G, Reicher H, Üllen A, Bernhart E, Waltl S, Kratzer I, Hermetter A, Hackl H, Trajanoski Z, Hrzenjak A, Malle E, Sattler W. Hypochlorite modification of sphingomyelin generates chlorinated lipid species that induce apoptosis and proteome alterations in dopaminergic PC12 neurons in vitro. Free Radic Biol Med 2010; 48:1588-600. [PMID: 20226853 PMCID: PMC4061462 DOI: 10.1016/j.freeradbiomed.2010.02.037] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [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: 09/28/2009] [Revised: 01/12/2010] [Accepted: 02/27/2010] [Indexed: 11/15/2022]
Abstract
Recent observations link myeloperoxidase (MPO) activation to neurodegeneration. In multiple sclerosis MPO is present in areas of active demyelination where the potent oxidant hypochlorous acid (HOCl), formed by MPO from H(2)O(2) and chloride ions, could oxidatively damage myelin-associated lipids. The purpose of this study was (i) to characterize reaction products of sphingomyelin (SM) formed in response to modification by HOCl, (ii) to define the impact of exogenously added SM and HOCl-modified SM (HOCl-SM) on viability parameters of a neuronal cell line (PC12), and (iii) to study alterations in the PC12 cell proteome in response to SM and HOCl-SM. MALDI-TOF-MS analyses revealed that HOCl, added as reagent or generated enzymatically, transforms SM into chlorinated species. On the cellular level HOCl-SM but not SM induced the formation of reactive oxygen species. HOCl-SM induced severely impaired cell viability, dissipation of the mitochondrial membrane potential, and activation of caspase-3 and DNA damage. Proteome analyses identified differential expression of specific subsets of proteins in response to SM and HOCl-SM. Our results demonstrate that HOCl modification of SM results in the generation of chlorinated lipid species with potent neurotoxic properties. Given the emerging connections between the MPO-H(2)O(2)-chloride axis and neurodegeneration, this chlorinating pathway might be implicated in neuropathogenesis.
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Affiliation(s)
- Christoph Nusshold
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Manfred Kollroser
- Institute of Forensic Medicine, Medical University of Graz, Graz, Austria
| | - Harald Köfeler
- Center of Medical Research, Medical University of Graz, Graz, Austria
| | - Gerald Rechberger
- Institute of Molecular Biosciences, Karl-Franzens University, Graz, Austria
| | - Helga Reicher
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Andreas Üllen
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Eva Bernhart
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Sabine Waltl
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Ingrid Kratzer
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Albin Hermetter
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
| | - Hubert Hackl
- Institute for Genomics and Bioinformatics, Graz University of Technology, Graz, Austria
| | - Zlatko Trajanoski
- Institute for Genomics and Bioinformatics, Graz University of Technology, Graz, Austria
| | - Andelko Hrzenjak
- Department of Pulmonology, Medical University of Graz, Graz, Austria
| | - Ernst Malle
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Wolfgang Sattler
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
- Corresponding author. Fax: +43 316 380 9615.
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16
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Bernhart E, Kollroser M, Rechberger G, Reicher H, Heinemann A, Schratl P, Hallström S, Wintersperger A, Nusshold C, DeVaney T, Zorn-Pauly K, Malli R, Graier W, Malle E, Sattler W. Lysophosphatidic acid receptor activation affects the C13NJ microglia cell line proteome leading to alterations in glycolysis, motility, and cytoskeletal architecture. Proteomics 2010; 10:141-58. [PMID: 19899077 DOI: 10.1002/pmic.200900195] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Microglia, the immunocompetent cells of the CNS, are rapidly activated in response to injury and microglia migration towards and homing at damaged tissue plays a key role in CNS regeneration. Lysophosphatidic acid (LPA) is involved in signaling events evoking microglia responses through cognate G protein-coupled receptors. Here we show that human immortalized C13NJ microglia express LPA receptor subtypes LPA(1), LPA(2), and LPA(3) on mRNA and protein level. LPA activation of C13NJ cells induced Rho and extracellular signal-regulated kinase activation and enhanced cellular ATP production. In addition, LPA induced process retraction, cell spreading, led to pronounced changes of the actin cytoskeleton and reduced cell motility, which could be reversed by inhibition of Rho activity. To get an indication about LPA-induced global alterations in protein expression patterns a 2-D DIGE/LC-ESI-MS proteomic approach was applied. On the proteome level the most prominent changes in response to LPA were observed for glycolytic enzymes and proteins regulating cell motility and/or cytoskeletal dynamics. The present findings suggest that naturally occurring LPA is a potent regulator of microglia biology. This might be of particular relevance in the pathophysiological context of neurodegenerative disorders where LPA concentrations can be significantly elevated in the CNS.
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Affiliation(s)
- Eva Bernhart
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Austria
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