Human Phagocytes Employ the Myeloperoxidase-Hydrogen Peroxide System to Synthesize Dityrosine, Trityrosine, Pulcherosine, and Isodityrosine by a Tyrosyl Radical-dependent Pathway

Jacob, Jason S.; Cistola, David P.; Hsu, Fong‐Fu; Muzaffar, Samar; Mueller, Dianne M.; Hazen, Stanley L.; Heinecke, Jay W.

doi:10.1074/jbc.271.33.19950

Cited by 142 publications

(125 citation statements)

References 52 publications

(73 reference statements)

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“…Exposure to myeloperoxidase/H 2 O 2 /NO 2 Ϫ , which is known to oxidize the tyrosine residues and is expected to cause the formation of o,oЈ-dityrosine (41)(42)(43), also yielded similar stable ␣-synuclein aggregates. The formation of a tyrosyl radical and its reaction with a tyrosyl radical on another ␣-synuclein molecule are the basis for o,oЈ-dityrosine covalent cross-linking (41).…”

Section: Discussionmentioning

confidence: 96%

Dityrosine Cross-linking Promotes Formation of Stable α-Synuclein Polymers

Souza¹,

Giasson²,

Chen³

et al. 2000

Journal of Biological Chemistry

533

225

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Intracellular proteinaceous aggregates are hallmarks of many common neurodegenerative disorders, and recent studies have shown that ␣-synuclein is a major component of several pathological intracellular inclusions, including Lewy bodies in Parkinson's disease (PD) and glial cell inclusions in multiple system atrophy. However, the molecular mechanisms underlying ␣-synuclein aggregation into filamentous inclusions remain unknown. Since oxidative and nitrative stresses are potential pathogenic mediators of PD and other neurodegenerative diseases, we asked if oxidative and/or nitrative events alter ␣-synuclein and induce it to aggregate. Here we show that exposure of human recombinant ␣-synuclein to nitrating agents (peroxynitrite/CO 2 or myeloperoxidase/H 2 O 2 /nitrite) induces formation of nitrated ␣-synuclein oligomers that are highly stabilized due to covalent cross-linking via the oxidation of tyrosine to form o,o-dityrosine. We also demonstrate that oxidation and nitration of pre-assembled ␣-synuclein filaments stabilize these filaments to withstand denaturing conditions and enhance formation of SDS-insoluble, heat-stable high molecular mass aggregates. Thus, these data suggest that oxidative and nitrative stresses are involved in mechanisms underlying the pathogenesis of Lewy bodies and glial cell inclusions in PD and multiple system atrophy, respectively, as well as ␣-synuclein pathologies in other synucleinopathies.Accumulations of proteinaceous fibrils are a common neuropathological feature of several different sporadic and hereditary neurodegenerative diseases (1, 2). The neuronal presynaptic protein ␣-synuclein is a conspicuous component of intraneuronal inclusions of Lewy bodies (LBs) 1 and Lewy neurites (3-11), two prominent pathological features of Parkinson's disease (PD). Mutations in ␣-synuclein have been linked to familial , and these mutations appear to cause biophysical changes in these proteins that accelerate their fibrillogenesis in vitro (15-18). However, LBs and Lewy neurites in sporadic PD and dementia with LBs (3-11) as well as glial cytoplasmic inclusions (GCIs) in multiple system atrophy (19 -23) contain filaments formed by wild-type ␣-synuclein. Moreover, high molecular mass aggregates of wild-type ␣-synuclein that are resistant to strong denaturing conditions have been recovered from purified LBs and GCIs, (4, 22-24), suggesting that covalently modified ␣-synuclein may be predisposed to form these inclusions. However, the precise molecular alterations of wild-type ␣-synuclein that lead to the formation of aggregates in these diseases are unknown.Oxidative stress has been implicated in pathogenic mechanisms of PD and many other neurodegenerative diseases (25)(26)(27). Both analytical and immunological methodologies have revealed the presence of oxidized and nitrated proteins in a number of neurodegenerative disorders (27-32), supporting a role for oxidants and nitrating agents in the development of these diseases. Moreover, ␣-synuclein inclusions in brains from patients with PD (28), ...

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Section: Discussionmentioning

confidence: 96%

Dityrosine Cross-linking Promotes Formation of Stable α-Synuclein Polymers

Souza¹,

Giasson²,

Chen³

et al. 2000

Journal of Biological Chemistry

533

225

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“…One reactive intermediate formed by MPO that may serve as a potential initiator of lipid peroxidation is tyrosyl radical (24), a resonance-stabilized intermediate capable of both initiating lipid peroxidation and forming stable phenolic cross-links on proteins (27)(28)(29). Protein-bound dityrosine, a characteristic molecular fingerprint, is enriched in human atheroma and at other sites of inflammation (29 -31), suggesting that MPO-generated tyrosyl radical may participate in lipid peroxidation in vivo.…”

mentioning

confidence: 99%

Myeloperoxidase Functions as a Major Enzymatic Catalyst for Initiation of Lipid Peroxidation at Sites of Inflammation

Zhang

Brennan

Shen³

et al. 2002

Journal of Biological Chemistry

Self Cite

393

289

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Initiation of lipid peroxidation and the formation of bioactive eicosanoids are pivotal processes in inflammation and atherosclerosis. Currently, lipoxygenases, cyclooxygenases, and cytochrome P450 monooxygenases are considered the primary enzymatic participants in these events. Myeloperoxidase (MPO), a heme protein secreted by activated leukocytes, generates reactive intermediates that promote lipid peroxidation in vitro. For example, MPO catalyzes oxidation of tyrosine and nitrite to form tyrosyl radical and nitrogen dioxide ( ⅐ NO 2 ), respectively, reactive intermediates capable of initiating oxidation of lipids in plasma. Neither the ability of MPO to initiate lipid peroxidation in vivo nor its role in generating bioactive eicosanoids during inflammation has been reported. Using a model of inflammation (peritonitis) with MPO knockout mice (MPO ؊/؊ ), we examined the role for MPO in the formation of bioactive lipid oxidation products and promoting oxidant stress in vivo. Electrospray ionization tandem mass spectrometry was used to simultaneously quantify individual molecular species of hydroxy-and hydroperoxy-eicosatetraenoic acids (H(P)ETEs), F 2 -isoprostanes, hydroxy-and hydroperoxy-octadecadienoic acids (H(P)ODEs), and their precursors, arachidonic acid and linoleic acid. Peritonitis-triggered formation of F 2 -isoprostanes, a marker of oxidant stress in vivo, was reduced by 85% in the MPO ؊/؊ mice. Similarly, formation of all molecular species of H(P)ETEs and H(P)ODEs monitored were significantly reduced (by at least 50%) in the MPO ؊/؊ group during inflammation. Parallel analyses of peritoneal lavage proteins for protein dityrosine and nitrotyrosine, molecular markers for oxidative modification by tyrosyl radical and ⅐ NO 2 , respectively, revealed marked reductions in the content of nitrotyrosine, but not dityrosine, in MPO ؊/؊ samples. Thus, MPO serves as a major enzymatic catalyst of lipid peroxidation at sites of inflammation. Moreover, MPO-dependent formation of ⅐ NO-derived oxidants, and not tyrosyl radical, appears to serve as a preferred pathway for initiating lipid peroxidation and promoting oxidant stress in vivo.

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“…This enzyme is commonly used to abolish the formation of tyrosyl radicals [10]. It is known that catalase in the process of decomposing H 2 O 2 forms endogenous tyrosyl radicals [43].…”

Section: Discussionmentioning

confidence: 99%

“…Neutrophil activation was induced by the addition of 1 mg/mL PMA (Sigma, St. Louis, MO, USA), 0.6 ng/mL TNF-a (BioSource, Camarrilo, CA, USA), 0.6 ng/mL IFN-g (BioSource) or 1 mM N-formyl-methionylleucyl-phenylalanine (fMLP) (Sigma) to the cell suspension in the cuvette. Dityrosine (dityramine) formation in the medium was measured continuously up to 20-40 min at excitation and emission wavelenghts of 325 nm and 405 nm, respectively [10]. Data were collected and analyzed using Microsoft Excel software.…”

Section: Fluorimetric Detection Of Extracellular Dityrosine Formationmentioning

confidence: 99%

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Identification of proteins in activated human neutrophils susceptible to tyrosyl radical attack. A proteomic study using a tyrosylating fluorophore

et al. 2004

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Tyrosyl radicals cross-linked to protein tyrosine residues (tyrosylated proteins) represent hallmarks of neutrophil-mediated injury at the inflammatory locus. Yet the proteins targeted by tyrosyl radicals in an intact cellular system remain to be elucidated. Here, we show that tyrosyl radicals generated by human neutrophils after activation by phorbol 12-myristate 13-acetate (PMA), interferon-g (IFN-g) or TNF-a could act in an autocrine manner by cross-linking to endogenous proteins. We have identified the tyrosylated proteins by using a membraneimpermeable tyrosine analogue, tyramine coupled to fluorescein (TyrFluo), in combination with proteomics techniques. Confocal microscopy images indicated that initially the tyrosylated proteins were localized in patches at the cell surface to become internalized subsequently. In the neutrophil membrane-associated proteome, lactoferrin was the prime target of tyrosylation. Out of three isoforms identified, an 80 kDa neutral isoform was tyrosylated more extensively than the 85 kD basic isoform, particularly after PMA activation. Although all three stimuli induced tyrosylation of the filamentous component vimentin, additional tyrosylated vimentin fragments were detected after IFN-g-and TNF-a-stimulation. Moreover, upon activation the bulk of vimentin behaved as a dimer (M r 120 kDa) being slightly tyrosylated, yet phosphorylated at Thr-425 possibly as a requirement for its externalization. Unexpectedly, bovine catalase added to end tyrosyl radicals formation was detected as a highly tyrosylated neutrophil-associated protein. A moderate stimulus-dependent tyrosylation of ATP synthaseb, a-enolase, glyceraldehyde 3-phosphate dehydrogenase, cytokeratin-10, filamin-A, and annexin-I was also observed. When the membrane-permeable probe (acetylTyrFluo) was used, protein tyrosylation was not observed indicating that the intracellular proteins were well protected against oxidative attack. This study shows that human neutrophils can modulate their proteome via a tyrosine oxidation pathway induced by pro-inflammatory mediators.

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Human Phagocytes Employ the Myeloperoxidase-Hydrogen Peroxide System to Synthesize Dityrosine, Trityrosine, Pulcherosine, and Isodityrosine by a Tyrosyl Radical-dependent Pathway

Cited by 142 publications

References 52 publications

Dityrosine Cross-linking Promotes Formation of Stable α-Synuclein Polymers

Dityrosine Cross-linking Promotes Formation of Stable α-Synuclein Polymers

Myeloperoxidase Functions as a Major Enzymatic Catalyst for Initiation of Lipid Peroxidation at Sites of Inflammation

Identification of proteins in activated human neutrophils susceptible to tyrosyl radical attack. A proteomic study using a tyrosylating fluorophore

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