Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02749 (beta2-glycoprotein I)
 836 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Appreciation of the multifactorial nature of atherosclerosis requires a broad understanding of the mechanisms that underlie its pathogenesis. Autoimmune factors have recently been shown to be associated with the initiation and progression of atherosclerosis. In this context, modified lipoproteins were explored because of their de-novo occurrence within the vessel wall, and heat shock proteins are also being reported by several authors as triggers of autoimmune-like reactions that associate with atherosclerosis. Antiphospholipid antibodies in general and anti-beta2-glycoprotein I (beta2GPI) antibodies in particular have been shown to confer a procoagulant tendency in humans, either in the presence or the absence of the antiphospholipid syndrome. These findings and the ability of antibodies to beta2GPI to activate monocytes and endothelial cells led us to consider whether they are proatherogenic. In a series of studies it was shown that inducing an immune response to beta2GPI in atherosclerosis-prone mice accelerated atherosclerosis. We also demonstrated the abundance of beta2GPI in the atheroma, in conjunction with immunopotent cells. Moreover, when beta2GPI-reactive lymph node and spleen cells were transferred to LDL-receptor-deficient mice they promoted fatty streak formation, proving a direct proatherogenic role for beta2GPI-specific lymphocytes. Perhaps the most important implications of the existence of antigen-specific immune reactions within the atheroma is the ability to exploit them for the purpose of selective immunomodulation. Indeed, we have found that inducing immunological tolerance to beta2GPI by prior oral feeding with the antigen resulted in a significant reduction in the extent of atherosclerotic lesions. Thus, beta2GPI is a candidate player in the atherosclerotic plaque, and can possibly be employed as an immunomodulator of plaque progression.
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PMID:Beta2-glycoprotein I and atherosclerosis. 1156 Nov 74

Antiphospholipid antibodies (APLAs) are a group of autoantibodies directed against certain phospholipids, or their protein cofactors. Assay of APLAs is important because their interaction with anionic phospholipid-protein cofactors can generate a syndrome of hypercoagulability associated with a wide variety of thromboembolic events. This article presents the characteristics of some APLAs [anticardiolipin antibodies (aCLAs), lupus anticoagulant (LA) and anti-beta2-glycoprotein I antibodies (anti-beta2-GPIAs)], their action, and their interaction with blood and endothelial cells. The presence of APLAs has been reported in many diseases (autoimmune diseases, atherosclerosis, infections, malignancies), being related to pathogenic mechanisms and/or to a more severe evolution of the disease.
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PMID:The antiphospholipid antibodies. 1203 12

beta 2-Glycoprotein I (beta 2-GPI) is a major antigen for antiphospholipid antibodies (aPL) present in patients with antiphospholipid syndrome (APS). We previously reported that beta 2-GPI specifically binds to oxidized low-density lipoprotein (oxLDL). Further, a ligand specific for beta 2-GPI, oxLig-1, purified from the extracted lipids of oxLDL was identified as 7-ketocholesterol-9-carboxynonanoate (i.e., 9-oxo-9-(7-ketocholest-5-en-3 beta-yloxy) nonanoic acid) OxLig-1 was recognized by beta 2-GPI and subsequently by anti-beta 2-GPI autoantibodies. Binding of liposomes containing oxLig-1 to macrophages were significantly enhanced in the presence of both beta 2-GPI and an anti-beta 2-GPI autoantibody derived from (NZW x BXSB) F1 mouse, an animal APS model, or from APS patients. Anti-beta 2-GPI autoantibodies derived from APS patients with episodes of arterial thrombosis were detected in ELISA, using a solid phase beta 2-GPI complex with oxLig-1. It was also reported that LDL-receptor-deficient mice that were fed a chow diet and immunized with beta 2-GPI had an accelerated atherosclerosis and that beta 2-GPI was abundantly expressed within subendothelial regions and intimal-medial borders of human atherosclerotic plaques. All of these observations strongly suggest that autoimmune atherogenesis linked to beta 2-GPI interaction with oxLDL and autoantibodies may be present in APS.
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PMID:Anti-beta 2-glycoprotein I autoantibodies and atherosclerosis. 1218 45

Atherosclerosis is an autoimmune/inflammatory disease associated with infectious, inflammatory, and autoimmune factors. Both humoral and cellular immune mechanisms have been proposed to participate in the onset and/or progression of atheromatous lesions. Heat-shock protein (hsp), oxidized low-density lipoprotein (LDL), and beta2-GPI have been reported to elicit humoral and cellular immune response in both experimental animals and humans. These autoantigens are expressed within atherosclerotic lesions. Immunization with the given autoantigens elicits an immune response that influences lesion progression. Atherosclerosis susceptibility can be transferred by autoantigen-sensitized lymphocytes from immunized animals. Patients with systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) have a high risk for atherosclerotic cardiovascular events. The traditional risk factors fail to fully account for accelerated atherosclerosis in SLE and APS. Immunological alterations, such as antibodies to oxidized LDL, antiphospholipid antibodies (aPL), antibodies to beta-2 Glycoprotein (anti-beta2-GPL), anti-prothrombin antibodies, may play a role in premature atherosclerosis in SLE and APS. Paraoxonase (PON1) is an enzyme with antioxidant activity attached to the circulating high-density lipoprotein (HDL) in plasma. Its function is to prevent oxidation of LDL, thereby accounting for the antioxidant properties and the atherosclerotic protective effects of HDL. The relationship between PON1 and aPL has been recently suggested. IgG anti-HDL and IgG anti-beta2-GPI antibodies were associated with reduced PON1 activity in patients with SLE and primary APS. The determination of classic and new factors, together with specific autoantibody titers and the use of Doppler carotid ultrasound, are useful methods to detect early atherosclerosis in SLE and PAPS. Therapeutic strategies, including early control of disease and other risk factors, are essential to reduce morbidity and mortality.
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PMID:Atherosclerosis and antiphospholipid syndrome. 1279 63

Antiphospholipid antibodies are commonly found in patients with systemic lupus erythematosus or the antiphospholipid syndrome, and a subset of such antibodies is associated with prothrombotic events such as stroke and with adverse pregnancy outcomes and fetal loss. We examined sera from 411 patients who were clinically characterized as to their periodontal disease status for serum levels of beta2-glycoprotein I-dependent anti-cardiolipin autoantibodies (anti-CL). The prevalence of patients with chronic periodontitis (CP) and generalized aggressive periodontitis (GAgP) positive for anti-CL (16.2% and 19.3%, respectively) was greater than that in healthy controls (NP) and localized aggressive periodontitis (LAgP) patients (6.8% and 3.2%). Patients with these autoantibodies demonstrated increased pocket depth and attachment loss compared with patients lacking the antibodies. Analysis of the data indicates that patients with generalized periodontitis have elevated levels of autoantibodies reactive with phospholipids. These antibodies could be involved in elevated risk for stroke, atherosclerosis, or pre-term birth in periodontitis patients.
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PMID:Anti-cardiolipin antibodies in sera from patients with periodontitis. 1457 6

We recently reported [J. Lipid Res. 42 (2001), 697; 43 (2002), 1486; 44 (2003), 716] that [beta2-glycoprotein I (beta2GPI) forms complexes with oxidized LDL (oxLDL) and autoantibodies against these complexes are present in patients with SLE and antiphospholipid syndrome (APS). The relationship of beta2GPI/oxLDL complexes and IgG autoantibodies against beta2GPI complexed with oxLig-1 (an oxLDL-derived ligand) with clinical manifestations of APS was studied in 150 APS and SLE patients. The beta2GPI/oxLDL levels of APS patients were similar to those of SLE patients without APS, but they were significantly higher than healthy individuals. There was no difference in the complex levels among the patients with arterial, venous thrombosis, or pregnancy morbidity. IgG anti-beta2GPI/oxLig-1 levels of APS were significantly higher than those of SLE without APS and healthy individuals. Further, antibody levels of APS patients with arterial thrombosis were significantly higher than those patients with venous thrombosis and pregnancy morbidity. Thus, oxidation of LDL leads the complex formation with beta2GPI in SLE and APS patients. In contrast, anti-beta2GPI/oxLig-1 autoantibodies were generated only in APS and were strongly associated with arterial thrombosis. These results suggest that autoantibodies against beta2GPI/oxLDL complexes are etiologically important in the development of atherosclerosis in APS.
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PMID:IgG autoantibodies against beta2-glycoprotein I complexed with a lipid ligand derived from oxidized low-density lipoprotein are associated with arterial thrombosis in antiphospholipid syndrome. 1476 53

The oxidative modification of low-density lipoprotein (LDL) in the intima of arteries contributes to the initiation and progression of atherosclerotic lesions. We have previously reported that oxidized LDL (oxLDL) interacts with an endogenous plasma protein, beta2-glycoprotein I (beta2GPI), to form complexes and that the interaction is mediated by oxLDL specific ligands. We have also demonstrated the presence of oxLDL/beta2GPI complexes in the blood stream of patients with systemic inflammatory and autoimmune diseases. These findings implicate that oxLDL/beta2GPI complexes are possible atherogenic autoantigens. Autoantibodies to oxLDL/beta2GPI complexes have been associated with arterial thrombosis. Further, circulating IgG immune complexes containing oxLDL and beta2GPI were also detected in patients with systemic lupus erythematosus (SLE) and/or antiphospholipid syndrome (APS). Although many unanswered questions remain about the exact pathogenic mechanism(s) involved, oxLDL/beta2GPI complexes may be described as metabolic products relevant in atherogenesis and as significant participants in autoimmune-mediated atherosclerosis.
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PMID:Are oxidized LDL/beta2-glycoprotein I complexes pathogenic antigens in autoimmune-mediated atherosclerosis? 1533 Apr 45

Diabetes mellitus (DM) is associated with oxidative stress, elevation of inflammatory markers and other mechanisms, which may contribute to accelerated atherosclerosis. The aim of the study was to determine prominent factors of these pathogenic processes in patients with DM, to examine their relationship in serum, and to find out the differences between DM1 and DM2. Advanced oxidation protein products (AOPP), C-reactive protein (CRP), pregnancy-associated plasma protein-A (PAPP-A), anticardiolipin antibodies (ACA) and anti-beta2-glycoprotein-1 antibodies (anti-beta2-GPI) were determined in 27 patients with DM1, 27 patients with DM2 and 23 healthy subjects. AOPP, CRP and anti-beta2-GPI were significantly elevated in DM2 in comparison with healthy subjects (p<0.01, p<0.0001, p<0.0001, respectively). In DM1, anti-beta2-GPI were elevated (p<0.0001) as well, but there was no increase of either AOPP or CRP. There was no difference in PAPP-A levels in DM1 or DM2 and healthy subjects. In DM 1, AOPP correlate significantly with anti-beta2-GPI (r = 0.68, p<0.05). In DM2, there is a significant correlation between anti-beta2-GPI and PAPP-A (r=0.45, p<0.05). Oxidative stress and inflammation are more expressed in DM2 and they are partly related. In DM1, oxidative stress seems to be in closer link to autoimmune reaction than to inflammation.
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PMID:Oxidative stress, inflammation and autoimmune reaction in type 1 and type 2 diabetes mellitus. 1535 43

Atherosclerosis is a chronic inflammatory process of the arterial wall associated with systemic and local immune responses to various antigens, oxidized low-density lipoprotein (oxLDL) being the most significant. Both IgM and IgG antibodies to oxLDL are produced during atherosclerosis. Some studies have shown that elevated levels of antibody to oxLDL correlate with the degree of atherosclerosis. Other studies reported that immunization of experimental animals with oxLDL induces high levels of antibodies to oxLDL, with decreased atherosclerosis, suggesting that the immune response to oxLDL may be antiatherogenic. The accelerated development of atherosclerosis has been observed in patients with systemic autoimmune diseases. In patients with antiphospholipid syndrome (APS), beta2-glycoprotein I (beta2GPI) is a major antigenic target for anticardiolipin antibodies (aCLs). We recently reported that oxLDL interacts with beta2GPI via oxLDL-derived specific ligands, such as 7-ketocholesteryl-9-carboxynonanoate (oxLig-1) to form complexes. In vitro, anti-beta2GPI autoantibodies bind to oxLDL/beta2GPI complexes that are actively taken up by macrophages via Fcgamma receptors. Circulating oxLDL/beta2GPI complexes were detected in patients with systemic lupus erythematosus (SLE) and APS, at higher levels than in healthy individuals. Autoantibodies against these complexes were also present; however, IgG anti-oxLig-1/beta2GPI antibody levels in SLE patients with APS were significantly higher than those in SLE patients without APS and those in healthy individuals.
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PMID:The role of innate and adaptive immunity to oxidized low-density lipoprotein in the development of atherosclerosis. 1612 86

Low-density lipoprotein (LDL) size, a coronary heart disease risk factor, is influenced by both genetic and environmental factors. Results from the Quebec Family Study (QFS) revealed that the LDL peak particle diameter (LDL-PPD) aggregates in families with a heritability coefficient above 50% and is affected by a major quantitative trait locus on chromosome 17q (LOD=6.8). Complex segregation analyses have consistently demonstrated a major gene effect influencing LDL size. In the present study, we report a similar analysis in the QFS cohort, which suggests that a major gene explains 23% of the variance in age-body mass index and triglyceride-adjusted LDL-PPD. The most intuitive positional candidate gene on chromosome 17q is the apolipoprotein H gene. Direct sequencing of the promoter, coding regions, and exon-intron splicing boundaries of this gene revealed the presence of three missense mutations and two polymorphisms in the untranslated regions. Using family-based association tests, none of these variants was individually associated with LDL-PPD. However, analysis of the haplotypes constructed from the three missense mutations, suggested that one particular haplotype (frequency=20.9%) was associated with a significant increase in LDL-PPD trait values (p=0.046). Taken together, these results suggest the presence of a major gene effect influencing LDL-PPD and a positive association with a positional candidate gene located on chromosome 17q. Replication of the association between apolipoprotein H gene haplotype and LDL-PPD is required before reaching firm conclusion.
Atherosclerosis 2005 Oct
PMID:Detection of a major gene effect for LDL peak particle diameter and association with apolipoprotein H gene haplotype. 1615 95


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