Abstract | OBJECTIVE: METHODS: Two MPO oxidation products, 3-chlorotyrosine and 3-nitrotyrosine, were quantified by tandem mass spectrometry (MS/MS) in in vitro model system studies and in plasma and HDL derived from healthy controls and RA subjects. MPO levels and cholesterol efflux were determined. Site-specific nitration and chlorination of apoA-1 peptides were quantified by MS/MS. RESULTS: RA subjects demonstrated higher levels of MPO, MPO-oxidised HDL and diminished cholesterol efflux. There was marked increase in MPO-specific 3-chlorotyrosine and 3-nitrotyrosine content in HDL in RA subjects consistent with specific targeting of HDL, with increased nitration in RA subjects with CVD. Cholesterol efflux capacity was diminished in RA subjects and correlated inversely with HDL 3-chlorotyrosine suggesting a mechanistic role for MPO. Nitrated HDL was elevated in RACVD subjects compared with RA subjects without CVD. Oxidative peptide mapping revealed site-specific unique oxidation signatures on apoA-1 for RA subjects with and without CVD. CONCLUSIONS: We report an increase in MPO-mediated HDL oxidation that is regiospecific in RA and accentuated in those with CVD. Decreased cholesterol efflux capacity due to MPO-mediated chlorination is a potential mechanism for atherosclerosis in RA and raises the possibility that oxidant resistant forms of HDL may attenuate this increased risk.
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Authors | Anuradha Vivekanandan-Giri, Jessica L Slocum, Jaeman Byun, Chongren Tang, Robin L Sands, Brenda W Gillespie, Jay W Heinecke, Rajiv Saran, Mariana J Kaplan, Subramaniam Pennathur |
Journal | Annals of the rheumatic diseases
(Ann Rheum Dis)
Vol. 72
Issue 10
Pg. 1725-31
(Oct 2013)
ISSN: 1468-2060 [Electronic] England |
PMID | 23313808
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
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Chemical References |
- Apolipoprotein A-I
- Lipoproteins, HDL
- 3-nitrotyrosine
- Tyrosine
- Cholesterol
- Peroxidase
- 3-chlorotyrosine
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Topics |
- Adult
- Aged
- Apolipoprotein A-I
(blood)
- Arthritis, Rheumatoid
(blood, complications)
- Cardiovascular Diseases
(blood, etiology)
- Case-Control Studies
- Cholesterol
(blood)
- Female
- Halogenation
(physiology)
- Humans
- Lipoproteins, HDL
(blood)
- Male
- Middle Aged
- Oxidation-Reduction
- Peptide Mapping
(methods)
- Peroxidase
(blood, physiology)
- Tandem Mass Spectrometry
(methods)
- Tyrosine
(analogs & derivatives, blood)
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