Search results for "Beta 2-Glycoprotein I"
showing 10 items of 10 documents
Liver is not the unique site of synthesis of beta 2-glycoprotein I (apolipoprotein H): evidence for an intestinal localization.
1997
Apolipoprotein H is a protein of about 50 kilodaltons, structurally related to the regulators of the complement activation family. Its physiological function is poorly understood but it has been implicated in lipid metabolism and coagulative pathways. The major site of synthesis is thought to be the liver. Several reports indicate that apolipoprotein H is the antigen of the antiphospholipid antibodies and also behaves as an acute-phase reactant. Moreover, 40% of plasma apolipoprotein H is associated with very low-density lipoprotein, high-density lipoprotein, and postprandial chylomicrons. In this study we investigated other sites of synthesis by reverse transcription/polymerase chain react…
Biosensor Analysis of β2-Glycoprotein I–Reactive Autoantibodies: Evidence for Isotype-Specific Binding and Differentiation of Pathogenic from Infecti…
2007
Abstract Background: For the laboratory diagnosis of the antiphospholipid syndrome (APS) we developed a biosensor with the ability to distinguish between disease-relevant anti-β2-glycoprotein I (β2GPI) autoantibodies (anti-β2GPI) and pathogen-specific β2GPI cross-reactive antibodies that occur transiently during infections. Methods: We used a surface plasmon resonance (SPR) biosensor device. For the detection of anti-β2GPI in serum samples, affinity-purified human β2GPI was covalently attached to a functionalized n-alkanethiol self-assembling monolayer on the biosensor chip. After verifying the specificity of the biosensor system with a panel of monoclonal antibodies to β2GPI, we analyzed s…
Interaction of inflammation, thrombosis, aspirin and enoxaparin in CNS experimental antiphospholipid syndrome
2008
Experimental antiphospholipid syndrome (eAPS) induced by immunization with beta(2)-glycoprotein I (beta(2)-GPI) causes behavioral hyperactivity. We assessed the role of thrombotic and inflammatory perivascular factors and standard APS therapies for CNS manifestations. Groups of mice (n=10 per group) were immunized once with beta(2)-GPI (eAPS) or adjuvant (controls) and treated daily from 1 month after immunization with either sham injections, aspirin (1.2 mg/kg) or enoxaparin (1 mg/kg) for 3 months. Serum antiphospholipid antibodies (aPL) and brain levels of tissue necrosis factor-alpha (TNF-alpha) and prostaglandin E (PGE) were then measured by ELISA and thrombin inhibitors by immunoblot. …
Investigations on the genetics and population genetics of the ?2 polymorphism
1970
The results of studies on 49 families with 107 children and various populations of Caucasoid, Negroid and Mongoloid origin concerning the genetics and population genetics of the β2-glycoprotein I polymorphism are reported. In general the genetical model proposed by Cleve (1968) is confirmed: two autosomal alleles BgN and BgD controlling the phenotypes Bg N-N, Bg N-D and Bg D-D. However, divergences from this model were found in two families. They indicate the assumption of non-genetic factors influencing the phenotype expression rather than more complicated genetical control mechanisms. Within Caucasoid populations phenotype and gene frequencies show almost a homogeneous distribution. This …
RT-PCR and in situ hybridization analysis of apolipoprotein H expression in rat normal tissues
2006
In this study, by using different techniques (i.e. Northern blot hybridization, RT-PCR and Southern blot hybridization) on various normal rat tissues, we were able to identify liver, kidney, heart, small intestine, brain, spleen, stomach and prostate as tissues in which the ApoH gene is transcribed. Moreover, for some of these tissues, by in situ hybridization, we found a specific localization of apoH transcripts. For instance epithelial cells of the bile ducts in liver and of the proximal tubules in kidney are the major sites of apoH synthesis. Our data suggest that some of the different physiological roles proposed for apoH could correlate with its direct expression, while others could co…
Structural and functional characterization of a human IgG monoclonal antiphospholipid antibody
2009
Antiphospholipid antibodies (aPL) are likely involved in the pathogenesis of the antiphospholipid syndrome (APS). This study analyzes the structural and functional characteristics of a human monoclonal aPL (HL7G) from the IgG2 subtype with λ light chains generated from a patient with primary APS and recurrent cerebral microemboli. DNA encoding the variable region of heavy and light chains of the antibody was sequenced, analyzed, and compared to HL5B a previously described monoclonal aPL from the same patient. Both antibodies are derived from the same germline genes. HL7G had similar but more extensive somatic mutations in the CDR1 and 2 regions than HL5B, indicating that both antibodies are…
Gene expression in mouse spermatogenesis during ontogenesis
2006
In this study, we evaluated the expression of genes probably involved in spermatogenesis in the mouse. We examined cytosolic chaperonin theta subunit (CCTtheta), Ngg1 interacting factor 3 like 1 binding protein 1 (NIF3L1 BP1) and apolipoprotein H (ApoH) expression during mouse onto-geny using RT-PCR. Testicular tissue was obtained from mice 3, 6, 8, 10, 12, 14, 18, 20 and 40 (adult) days after birth. For each mouse, one testis was used for histological examination, whereas RNA was extracted from the controlateral testis for expression analysis. RT-PCR analysis showed that CCTtheta gene expression was low until day 10, but increased drastically afterwards. At this age, spermatocytes started …
Generation and characterization of three monoclonal IgM antiphospholipid antibodies recognizing different phospholipid antigens.
2005
Antiphospholipid antibodies (APLs) might be involved in the pathogenesis of the antiphospholipid syndrome (APS). This study analyzes the structural characteristics of monoclonal APLs derived from patients with this disease. Patient-derived B cells were immortalized using Epstein-Barr virus transformation and subsequent fusion to the myeloma cell line CB-F7. APL-producing hybridomas were cloned to obtain cell lines producing monoclonal APL. DNA encoding the variable region of heavy and light chains of the antibodies was sequenced and analyzed regarding their usage within the V-gene family and the existence of somatic hypermutation. Binding patterns of APL to various phospholipids and beta-2-…
A case of Waldenstroem's disease with a monoclonal IgM antiphospholipid antibody
2002
The antiphospholipid syndrome (APS) was described in 1983 as a clinical entity characterized by venous and arterial thrombosis, thrombocytopenia, and recurrent fetal loss. The serological markers of APS are antiphospholipid antibodies (APLA) directed mainly against anionic phospholipids, usually cardiolipin but also phosphatidylserine. Some APLA exhibit lupus anticoagulant activity. Monoclonal gammopathy sometimes occurs with the presence of autoantibodies. In this paper, we describe a patient with the diagnosis of immunocytoma with an IgM, kappa paraprotein with apparent specificity against anionic phospholipids, and lupus anticoagulant activity, but no clinical signs of APS. We describe i…
Beta-2-glycoprotein I is growth regulated and plays a role as survival factor for hepatocytes
2004
Beta-2-glycoprotein I (beta(2)GPI) is mainly produced by the liver and is found in plasma partially associated to lipoproteins. Although various properties have been attributed to this protein, its physiological role remains still unclear. We investigated its expression in cultured liver cells and in regenerating liver. Expression studies in HepG2 cells demonstrate that beta(2)GPI mRNA is regulated in a cell cycle-dependent manner, with very low expression in low cycling conditions and increasing levels in proliferating cells. p21 WAF-dependent growth arrest, induced by butyrate treatment, down-regulate beta(2)GPI mRNA levels. Immunolocalization in normal rat liver shows a non-homogeneous p…