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1.
J Int Med Res ; 39(5): 1917-22, 2011.
Article in English | MEDLINE | ID: mdl-22117994

ABSTRACT

Serum amyloid A low-density lipoprotein (SAA-LDL) is formed by an oxidative interaction and is considered to be a new marker related to oxidative modification of LDL. As the effect of smoking on oxidized LDL is of concern, this study investigated the association between SAA-LDL and smoking status. A total of 578 Japanese obese outpatients (mean ± SD age 50.5 ± 14.3 years) were studied. Smoking status was examined via a self-reported questionnaire. Cardio metabolic variables, including high-sensitivity Creactive protein (hsCRP), were analysed in addition to SAA-LDL. There was an increasing trend in SAA-LDL levels from non- to ex- to current smokers, and significantly higher SAA-LDL levels were observed in current smokers versus non-smokers (median SAA-LDL level 36 µg/ml versus 28 µg/ml, respectively). This significant difference was reduced after adjusting for multiple confounders, including lipid levels. Smoking may be associated with increased levels of SAA-LDL in an obese Japanese population, but further studies are needed.


Subject(s)
Lipoproteins, LDL/blood , Obesity/blood , Serum Amyloid A Protein/analogs & derivatives , Smoking/blood , Adult , Aged , Biomarkers/blood , Blood Glucose , Blood Pressure , C-Reactive Protein/metabolism , Cholesterol/blood , Cross-Sectional Studies , Female , Humans , Japan , Male , Middle Aged , Oxidation-Reduction , Surveys and Questionnaires
2.
Biochem Biophys Res Commun ; 332(2): 352-6, 2005 Jul 01.
Article in English | MEDLINE | ID: mdl-15910745

ABSTRACT

The main focus of the serum amyloid A (SAA) family has been on the acute phase isoforms. However, the constitutive isoform (SAA4) may have a strong effect on the metabolism of human serum lipoproteins. In this study, the SAA4 protein was examined in the high-density lipoprotein fraction of both healthy and diseased individuals. Novel isoforms of SAA4 were detected using ultracentrifugation combined with solid-phase extraction and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Three truncated isoforms were identified as well as two glycosylated isoforms. Patterns of isoform distribution may be significant for assessment of cardiovascular risk as well as direction of patient treatment.


Subject(s)
Coronary Artery Disease/blood , Serum Amyloid A Protein/analogs & derivatives , Serum Amyloid A Protein/analysis , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Adult , Biomarkers/blood , Blood Chemical Analysis/methods , Humans , Lipoproteins/blood , Lipoproteins/classification , Protein Isoforms/analogs & derivatives , Protein Isoforms/blood , Protein Isoforms/classification , Serum Amyloid A Protein/classification
3.
FEMS Immunol Med Microbiol ; 38(1): 81-4, 2003 Aug 18.
Article in English | MEDLINE | ID: mdl-12900059

ABSTRACT

We studied here the effect of the acute phase protein serum amyloid A (SAA) on the oxidative burst of neutrophils. Incubation of neutrophils with SAA increased the rate of oxygen uptake and the production of reactive oxygen species of neutrophils activated with opsonized zymosan (OZ). The increment in the neutrophil oxidative burst was dependent on SAA concentration in the range of 3-33 microg protein ml(-1) and was observed only in the presence of a relatively low amount of OZ (1 x 10(6) particles ml(-1)). SAA did not affect oxygen consumption and reactive oxygen production triggered by other stimuli, such as f-Met-Leu-Phe, phorbol myristate acetate or non-opsonized zymosan. Our finding points to a priming effect of SAA probably associated with mobilization of receptors for opsonized particles and strengthens the role of SAA as an effector of neutrophil functions in inflammation.


Subject(s)
Neutrophil Activation/drug effects , Neutrophils/drug effects , Serum Amyloid A Protein/pharmacology , Humans , Neutrophils/physiology , Oxygen/blood , Serum Amyloid A Protein/analogs & derivatives
4.
J Lab Clin Med ; 132(5): 414-20, 1998 Nov.
Article in English | MEDLINE | ID: mdl-9823935

ABSTRACT

Serum amyloid A (SAA) is an acute phase reactant whose levels in the blood rise as part of the body's response to stress and inflammation. Previous studies have suggested that SAA may carry an anti-inflammatory potential. We evaluated the effects of SAA on human neutrophils activated by N-formyl-methionyl-leucyl-phenylalanine (fMLP) in vitro. At concentrations higher than 10 microg/mL, SAA inhibited neutrophil myeloperoxidase (MPO) release. This effect was located in the N-terminal--that is, amino acid residues 1-14--of the SAA molecule. Directed neutrophil migration was inhibited at the same SAA concentrations. Several amino acid residues (1-14, 15-104, 83-104) contributed to this effect. Neutrophil O2- production was inhibited at low concentrations of SAA (0.1 to 1 microg/ml) and was stimulated at concentrations higher than 50 microg/mL. Neutrophil O2- production induced by phorbol myristate acetate (PMA) and O2- generated by the xanthine-xanthine oxidase reaction were not affected by SAA. These results add to previous data suggesting that SAA, at concentrations recorded in the serum during inflammation, modulates neutrophil function; thus it may play a role in the down-regulation of the inflammatory process.


Subject(s)
Neutrophils/physiology , Serum Amyloid A Protein/pharmacology , Adult , Cell Degranulation/drug effects , Chemotaxis, Leukocyte/drug effects , Dose-Response Relationship, Drug , Female , Humans , In Vitro Techniques , Male , N-Formylmethionine Leucyl-Phenylalanine/pharmacology , Neutrophil Activation/drug effects , Peptide Fragments/chemistry , Peptide Fragments/pharmacology , Peroxidase/metabolism , Recombinant Proteins/pharmacology , Serum Amyloid A Protein/analogs & derivatives , Superoxides/metabolism
5.
Lab Invest ; 75(3): 371-5, 1996 Sep.
Article in English | MEDLINE | ID: mdl-8804360

ABSTRACT

Secondary amyloidosis, a serious complication of chronic inflammatory diseases, is caused by the deposition of amyloid fibrils in various organs. The major component of amyloid fibrils is derived from serum amyloid A protein (SAA) by proteolysis. To explore the mechanisms of amyloidogenesis, we measured SAA concentrations in the sera of 38 patients with rheumatoid arthritis (RA) without secondary amyloidosis and in the sera of 18 RA patients with secondary amyloidosis, using the latex agglutination immunoassay. We also determined whether SAA was present as a full-length protein in the sera of RA patients by immunoblotting. Although SAA concentrations were elevated in the sera, there were no significant differences in these concentrations between RA patients without amyloidosis (128.2 +/- 145.4 micrograms/ml) and RA patients with amyloidosis (165.0 +/- 162.9 micrograms/ml). To test for qualitative abnormalities of SAA, the isolated SAA proteins from individual RA patients were analyzed by anti-SAA immunoblot. In addition to full-length SAA protein, 6-kd and 4.5-kd SAA-derived fragments were detected in the sera of RA patients, and the ratio of these fragments to total SAA proteins was significantly higher in RA patients with amyloidosis (37.0% +/- 0.7%) compared with that of RA patients without amyloidosis (15.0% +/- 5.5%). Although a high serum level of SAA is a predisposing condition for amyloid formation in RA patients, our data suggest that the increased circulating proteolytic cleavage of SAA may potentially contribute to the development of AA-amyloid deposition.


Subject(s)
Amyloidosis/blood , Amyloidosis/etiology , Arthritis, Rheumatoid/blood , Arthritis, Rheumatoid/complications , Serum Amyloid A Protein , Adult , Aged , Chromatography, Affinity , Female , Humans , Latex Fixation Tests , Male , Middle Aged , Osmolar Concentration , Serum Amyloid A Protein/analogs & derivatives
6.
Am J Pathol ; 143(5): 1480-5, 1993 Nov.
Article in English | MEDLINE | ID: mdl-7901995

ABSTRACT

Inbred CE/J mice have been identified as extremely resistant to azocasein-induced amyloidosis relative to five commonly used inbred strains, A/J, CBA/J, C57BL/6J, C3H/HeN, and SJL/J. The enhanced amyloid resistance in CE/J mice seems to derive from the novel structure of the SAA gene family in CE/J mice, as determined by Southern blot hybridization analysis of SAA gene structure and isoelectric focusing analysis of acute phase SAA proteins in the six inbred strains. In CE/J mice, a single, novel SAA isoform of pI 6.15 is present, whereas in the other strains the amyloidogenic SAA2 isoform (pI 6.3) is codominantly expressed with SAA1 (pI 6.45). Two other inbred strains, PERU and IS/CAM, share common SAA specific HindIII DNA fragments with CE/J mice. Wild-derived Mus musculus mice differ from all of the inbred strains studied, both in SAA gene structure and in the pattern of SAA isoform production; two isoforms, one pI 6.15 and the other pI 6.3 (corresponding to SAA2), were codominantly expressed. Only the pI 6.15 isoform, not SAA1 and 2, was produced by CE/J mice in response to lipopolysaccharide, casein, silver nitrate, interleukin-1, or tumor necrosis factor; tumor necrosis factor was a weaker stimulus than interleukin-1 for the pI 6.15 isoform as it is for SAA1 and 2 production in the other inbred strains. This study provides a new line of evidence supporting the role of precursor structure as a determining factor in murine amyloid A amyloidosis and provides a valuable model for studies of amyloidogenesis.


Subject(s)
Amyloidosis/immunology , Mice, Inbred Strains , Serum Amyloid A Protein/genetics , Acute-Phase Reaction/blood , Amyloidosis/chemically induced , Amyloidosis/genetics , Animals , Caseins , Disease Models, Animal , Female , Immunity, Innate , Isoelectric Focusing , Male , Mice , Polymorphism, Restriction Fragment Length , Serum Amyloid A Protein/analogs & derivatives , Serum Amyloid A Protein/analysis , Species Specificity
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