Tatsuji Yasuda

Kokura Memorial Hospital, Kitakyūshū, Fukuoka, Japan

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Publications (31)140.95 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Endometriosis has been proposed to be an autoimmune disease because of the presence of a variety of autoantibodies specific for endometrial or ovarian antigens. The object of the present study is to characterize binding specificity of anti-laminin-111 autoantibodies in infertile patients with endometriosis and to investigate whether these autoantibodies affect the in vitro embryo development. An ELISA analysis using overlapping synthesized peptides that covered the entire G domain of laminin-α1 chain was performed in infertile patients with endometriosis (n = 45). Mouse blastocysts were cultured in media containing the purified IgG from one antibody-positive serum on laminin-111-coated dishes. Anti-laminin-111 autoantibodies were directed to several particular biologically functional peptide sequences in laminin-α 1 chain G domain. The tested IgG significantly inhibited the extent of in vitro trophoblast outgrowth. Anti-laminin-111 autoantibodies may have major pathogenic roles on early reproductive failure including endometriosis-associated infertility.
    American Journal Of Reproductive Immunology 08/2011; 66(2):90-9. DOI:10.1111/j.1600-0897.2010.00956.x · 3.32 Impact Factor
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    ABSTRACT: 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.
    International Reviews Of Immunology 08/2009; 21(1):51-66. DOI:10.1080/08830180210414 · 5.28 Impact Factor
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    ABSTRACT: Beta(2)-glycoprotein I (beta(2)GPI) is known as a major autoantigen for antiphospholipid antibodies. Our recent data show that binding of beta(2)GPI to oxidized low-density lipoprotein (oxLDL) or to liposomes containing anionic phospholipid(s) may facilitate the presentation of beta(2)GPI's epitope by macrophages/dendritic cells to autoreactive T cells. In the present study, we investigated intracellular trafficking of beta(2)GPI and its complexes with oxLDL or liposomes containing phosphatidylserine (PS-liposomes) in mouse macrophage-like J774 cells. A relatively small amount of non-complexed beta(2)GPI was taken up and stagnated in the late endosome after incubating for 16h. In contrast, beta(2)GPI complexes with oxLDL or PS-liposomes were transported into the lysosome. In the presence of the IgG anti-beta(2)GPI autoantibody, WB-CAL-1, beta(2)GPI/oxLDL complexes were rapidly incorporated into intracellular space and were finally localized in the lysosome. Interestingly, in vitro pulses by beta(2)GPI/oxLDL complexes together with WB-CAL-1 led to the expression of membranous CD36 as well as Fcgamma type I receptors (FcgammaRI). These observations suggest that IgG immune complexes of beta(2)GPI/oxLDL provide not only FcgammaRI- but also scavenger receptor-mediated uptake of beta(2)GPI/oxLDL complexes by macrophages. Thus, beta(2)GPI/oxLDL complexes as a major atherogenic autoantigen and IgG anti-beta(2)GPI autoantibodies may facilitate antigen presentation and foam cell formation in antiphospholipid syndrome.
    Journal of Autoimmunity 09/2007; 29(2-3):164-73. DOI:10.1016/j.jaut.2007.07.003 · 7.02 Impact Factor
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    ABSTRACT: C-reactive protein (CRP) is one of the strongest independent predictors of cardiovascular disease. We have previously reported that oxidized LDL (oxLDL) interacts with beta2-glycoprotein I (beta2GPI), implicating oxLDL/beta2GPI complexes as putative autoantigens in autoimmune-mediated atherosclerotic vascular disease. In this study, we investigated the interaction of CRP with oxLDL/beta2GPI complexes and its association with atherosclerosis in patients with diabetes mellitus (DM). CRP/oxLDL/beta2GPI complexes were predominantly found in sera of DM patients with atherosclerosis. In contrast, noncomplexed CRP isoforms were present in sera of patients with acute/chronic inflammation, i.e., various pyrogenic diseases, rheumatoid arthritis (RA), and DM. Immunohistochemistry staining colocalized CRP and beta2GPI together with oxLDL in carotid artery plaques but not in synovial tissue from RA patients, strongly suggesting that complex formation occurs during the development of atherosclerosis. Serum levels of CRP correlated with soluble forms of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1, and oxLDL/beta2GPI complexes correlated with total cholesterol and hemoglobin A1c. Thus, the generation of CRP/oxLDL/beta2GPI complexes seems to be associated with arterial inflammation, hyperglycemia, and hypercholesterolemia. CRP/oxLDL/beta2GPI complexes can be distinguished from pyrogenic noncomplexed CRP isoforms and may represent a more specific and predictive marker for atherosclerosis.
    The Journal of Lipid Research 05/2007; 48(4):768-81. DOI:10.1194/jlr.M600414-JLR200 · 4.73 Impact Factor
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    ABSTRACT: Several interpretations have been made regarding the specificity of antiphospholipid antibodies and antibodies against oxidized low-density lipoprotein (oxLDL), but these are still controversial. In the present study, we delineated specificity of these two types of antibodies and analyzed their regulatory effect on oxLDL and/or beta( 2)-glycoprotein I (beta(2)GPI) binding to macrophages. Scavenger receptor-mediated binding of oxLDL (or its beta(2)GPI complexes) to macrophages was observed and the binding was partly prevented by beta( 2)GPI. The IgG monoclonal anti-beta(2)GPI antibody (WB-CAL-1), which was derived from NZW x BXSB F1 mouse (a model of antiphospholipid syndrome), significantly increased the oxLDL/beta(2)GPI binding to macrophages. In contrast, IgM anti-oxLDL natural antibody, EO6 (derived from apoe( -/-) mouse), prevented the binding. Different antigenic specificity of these antibodies to oxLDL and its beta(2)GPI complexes was also confirmed in TLC-ligand blot and ELISA. Thus, IgG anti-beta(2) GPI autoantibodies contribute to lipid metabolism (housekeeping of oxLDL by macrophages) whereas IgM natural anti-oxLDL antibodies may protect against atherogenesis. In addition, in vitro data suggest that relatively high dose of intravenous immunoglobulin preparations (mainly contain IgG anti-oxLDL antibodies) might also prevent atherogenesis by inhibiting the oxLDL binding to macrophages.
    Lupus 02/2007; 16(12):929-38. DOI:10.1177/0961203307084170 · 2.48 Impact Factor
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    ABSTRACT: Beta2-glycoprotein I (beta2-GPI) is a major antigen for anti-cardiolipin antibodies and their epitopes are cryptic. Conformation of each domain of beta2-GPI was optimized from its crystal structure by energy minimization and by molecular dynamics simulation. Three electrostatic interactions, i.e. D193-K246, D222-K317 and E228-K308, were observed between domains IV and V in the optimized structure that was constructed based on the consensus sequences obtained by the phage-displayed random peptide library. Antigenic structures determined by the epitope mapping mainly consisted of hydrophobic amino acids located on two discontinuous sequences in domain IV. These amino acid clusters, as an epitope, were covered by domain V and were of a hidden nature. A similar but incomplete counterpart to the epitopic clusters was found in domain I but was not in domains II or III. Binding of anti-beta2-GPI auto-antibodies to solid-phase beta2-GPI was significantly reduced either by L replacement for W235, a common amino acid component for the epitopes, or by V replacement for all of D193, D222 and E228. Structural analysis indicated a hypothesis that these electrostatic interactions between domains IV and V retained exposure to W235 and that epitope spreading occurred in the region surrounding W235. Thus, epitopic structures recognized by anti-beta2-GPI auto-antibodies are cryptic and inter-domain electrostatic interactions are involved in their in exposure.
    International Immunology 01/2006; 17(12):1533-42. DOI:10.1093/intimm/dxh330 · 3.18 Impact Factor
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    ABSTRACT: Laminin-1 is a structural glycoprotein that forms an integral part of the scaffolding of basement membranes, and plays an important role during embryonic development. We have recently demonstrated a significant association between anti-laminin1 antibodies (Abs) and reproductive failure, such as recurrent spontaneous abortions and infertility-associated endometriosis in both human and mouse studies. In the present study, we established an IgM (micro, kappa) monoclonal anti-laminin-1 Ab (AK8) by immunizing mice with mouse Engelbreth-Holm-Swarm sarcoma (EHS)-derived laminin-1. The AK8 monoclonal antibody (mAb) reacted with particular peptide sequences from the globular G domain of mouse laminin-alpha1 chain of using ELISA and Western blot techniques. The peptide tertiary structure of the epitope recognized by AK8 mAb was predicted using eight synthesized domain peptide sequences and three consensus sequences obtained by phage displayed random peptide library. Basement membranes of endometrium of pregnant mice and humans were immunostained with AK8 mAb. Thus, AK8 mAb recognized a common structure present in the G domain of the laminin-alpha1 chain in both mice and humans. The passive immunization of mice with AK8 mAb may represent a suitable animal model for anti-laminin-1 Ab-mediated reproductive failure.
    Clinical and Developmental Immunology 04/2005; 12(1):67-73. DOI:10.1080/17402520400014168 · 2.93 Impact Factor
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    ABSTRACT: Peroxidation of low-density lipoprotein (LDL) plays an important role in the development of dyslipidemias associated with the progression of chronic renal disorders. We recently reported [J Lipid Res 2001;42:697, 2002;43:1486, 2003;44:716] that oxidized LDL (oxLDL) interacts with an endogenous plasma protein, beta2-glycoprotein I (beta2GPI), via specific ligands. In the present study, the prevalence and clinical significance of oxLDL/beta2GPI complexes were evaluated in patients with chronic renal disorders. Serum levels of oxLDL/beta(2)GPI complexes were measured by ELISA in patients with chronic renal disease and their association with clinical manifestations was assessed. The serum levels of oxLDL/beta2GPI complexes were significantly higher in patients with chronic renal failure (CRF), chronic nephritis (CN) and diabetes mellitus than those in healthy individuals. The presence of complexes in patients with CN was significantly associated with high dietary protein and sodium chloride intake, but not with lipid metabolic parameters. Malondialdehyde-modified LDL was significantly associated with total cholesterol and LDL cholesterol in all patient groups, but did not correlate with renal function parameters. Serum oxLDL/beta2GPI complexes, generated by oxidative stress and associated with high dietary protein and salt intake, might be a novel risk factor and a diagnostic marker for the development of chronic renal diseases, especially IgA nephropathy.
    Nephron Clinical Practice 02/2004; 98(1):c15-24. DOI:10.1159/000079923 · 1.65 Impact Factor
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    ABSTRACT: Beta2-glycoprotein I (beta2-GPI) is a major antigen for antiphospholipid antibodies (Abs, aPL) present in patients with antiphospholipid syndrome (APS). We recently reported (J. Lipid Res., 42: 697, 2001; J. Lipid Res., 43: 1486, 2002) that beta2-GPI specifically binds to Cu2+-oxidized LDL (oxLDL) and that the beta2-GPI ligands are omega-carboxylated 7-ketocholesteryl esters. In the present study, we demonstrate that oxLDL forms stable and nondissociable complexes with beta2-GPI in serum, and that high serum levels of the complexes are associated with arterial thrombosis in APS. A conjugated ketone function at the 7-position of cholesterol as well as the omega-carboxyl function of the beta2-GPI ligands was necessary for beta2-GPI binding. The ligand-mediated noncovalent interaction of beta2-GPI and oxLDL undergoes a temperature- and time-dependent conversion to much more stable but readily dissociable complexes in vitro at neutral pH. In contrast, stable and nondissociable beta2-GPI-oxLDL complexes were frequently detected in sera from patients with APS and/or systemic lupus erythematodes. Both the presence of beta2-GPI-oxLDL complexes and IgG Abs recognizing these complexes were strongly associated with arterial thrombosis. Further, these same Abs correlated with IgG immune complexes containing beta2-GPI or LDL. Thus, the beta2-GPI-oxLDL complexes acting as an autoantigen are closely associated with autoimmune-mediated atherogenesis.
    The Journal of Lipid Research 05/2003; 44(4):716-26. DOI:10.1194/jlr.M200329-JLR200 · 4.73 Impact Factor
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    ABSTRACT: Laminin-1, a multifunctional glycoprotein of the basement membrane, is thought to be important in embryogenesis, embryonic implantation, and placentation. We recently showed that serum IgG anti-laminin-1 autoantibodies (auto-Abs) are associated with recurrent first-trimester miscarriages. The present study assessed the clinical significance of anti-laminin-1 Abs with infertility, accompanied with or without endometriosis. Sixty-eight infertile patients who underwent laparoscopy or laparotomy and 39 healthy non-pregnant women were tested for IgG anti-laminin-1 Abs. The association between the Abs and endometriosis was analysed. The presence of laminin-1 mRNA was detected in endometriotic lesions. Twenty infertile patients were positive for anti-laminin-1 Abs. The Ab levels in those patients were significantly higher than those in healthy non-pregnant women (P = 0.0005). The presence of the Abs was significantly associated with endometriosis in those patients (P = 0.0096). The Abs recognized a particular domain, i.e., the laminin-alpha1 chain G domain. mRNA encoding laminin-alpha1, -beta1, and -gamma1 chains was expressed in 90% of endometriotic lesions. IgG anti-laminin-1 Abs were significantly associated with endometriosis in infertile patients. The Abs might be clinically important in the development of autoimmune-mediated reproductive failures and the assessment of the Abs may provide a novel non-invasive diagnosis of endometriosis.
    Human Reproduction 04/2003; 18(3):544-9. DOI:10.1093/humrep/deg148 · 4.59 Impact Factor
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    ABSTRACT: beta(2)-Glycoprotein I (beta(2)-GPI) is a major antigen for anticardiolipin antibodies (aCL, Abs) present in patients with antiphospholipid syndrome. We recently reported that beta(2)-GPI specifically binds to oxidized LDL (oxLDL) and that the beta(2)-GPI's major ligand, oxLig-1 is 7-ketocholesteryl-9-carboxynonanoate (Kobayashi, K., E. Matsuura, Q. P. Liu, J. Furukawa, K. Kaihara, J. Inagaki, T. Atsumi, N. Sakairi, T. Yasuda, D. R. Voelker, and T. Koike. 2001. A specific ligand for beta(2)-glycoprotein I mediates autoantibody-dependent uptake of oxidized low density lipoprotein by macrophages. J. Lipid Res. 42: 697-709). In the present study, we demonstrate that omega-carboxylated 7-ketocholesteryl esters are critical for beta(2)-GPI binding. A positive ion mass spectrum of a novel ligand, designated oxLig-2, showed fragmented ions at m/z 383 and 441 in the presence of acetone, which share features of oxLig-1 and 7-ketocholesterol. In the negative ion mode, ions at m/z 627, 625, and 243 were observed. oxLig-2 was most likely 7-ketocholesteryl-12-carboxy (keto) dodecanoate. These ligands were recognized by beta(2)-GPI. Liposome binding to macrophages was significantly increased depending on the ligand's concentration, in the presence of beta(2)-GPI and an anti-beta(2)-GPI Ab. Synthesized variant, 7-ketocholesteryl-13-carboxytridecanoate (13-COOH-7KC), also showed a significant interaction with beta(2)-GPI and a similar binding profile with macrophages. Methylation of the carboxyl function diminished all of the specific ligand interactions with beta(2)-GPI. Thus, omega-carboxyl variants of 7-ketocholesteryl esters can mediate anti-beta(2)-GPI Ab-dependent uptake of oxLDL by macrophages, and autoimmune atherogenesis linked to beta(2)-GPI interaction with oxLDL.
    The Journal of Lipid Research 10/2002; 43(9):1486-95. · 4.73 Impact Factor
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    ABSTRACT: beta(2)-Glycoprotein I (beta(2)-GPI) is a major antigen for antiphospholipid antibodies (Abs) present in patients with the antiphospholipid syndrome (APS). We previously reported that beta(2)-GPI specifically binds to oxidized low density lipoprotein (oxLDL), but not to native low density lipoprotein (LDL). In the present study, a ligand specific for beta(2)-GPI, oxLig-1, was purified from the extracted lipids of oxLDL. The structure of oxLig-1 was shown to be identical to that of synthesized 7-ketocholesteryl-9-carboxynonanoate by mass spectroscopy and nuclear magnetic resonance analyses. Both purified and synthesized oxLig-1 were recognized by beta(2)-GPI and subsequently by anti-beta(2)-GPI auto-Abs, either in enzyme-linked immunosorbent assay (ELISA) or in ligand blot analysis. Binding of liposomes containing oxLig-1 (oxLig-1-liposomes) to mouse macrophages, J774A.1 cells, was relatively low, as compared with that of phosphatidylserine (PS)-liposomes. In contrast, binding of oxLig-1-liposomes was enhanced more than 10-fold in the presence of both beta(2)-GPI and an anti-beta(2)-GPI auto-Ab (WB-CAL-1), derived from (NZW x BXSB) F1 mouse, an animal APS model. Anti-beta(2)-GPI auto-Abs derived from APS patients with episodes of arterial thrombosis were detected in ELISA, using a solid phase oxLig-1 complexed with beta(2)-GPI. We suggest that autoimmune atherogenesis linked to beta(2)-GPI interaction with oxLDL and Abs may be present in APS.
    The Journal of Lipid Research 06/2001; 42(5):697-709. · 4.73 Impact Factor
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    ABSTRACT: The present study assesses the clinical significance of anti-laminin-1 auto-antibodies (auto-Abs) in recurrent miscarriages. A total of 207 recurrent aborters with a history of two or more consecutive first-trimester miscarriages were tested for the presence of anti-laminin-1 Abs, beta2-glycoprotein I-dependent anticardiolipin Abs, lupus anticoagulants, anti-DNA Abs, and anti-nuclear Abs, before they had conceived again. Recurrent aborters then were followed up during subsequent pregnancies and their outcomes were evaluated relative to their blood test results prior to pregnancy. Fifty-five (31.1%) women out of 177 recurrent aborters were positive for IgG anti-laminin-1 auto-Abs. The levels of IgG anti-laminin-1 auto-Abs in recurrent aborters were significantly higher than those in healthy pregnant women and in healthy non-pregnant women (P = 0.0043 and 0.0073, respectively). The live birth rate of subsequent pregnancies in IgG anti-laminin-1 auto-Abs-positive recurrent aborters was significantly lower than the IgG anti-laminin-1 auto-Abs-negative recurrent aborters (P = 0.0320). There were no specifically significant relationships observed between IgG anti-laminin-1 auto-Abs and other tested auto-Abs. IgG anti-laminin-1 auto-Abs are associated with recurrent miscarriages and the subsequent pregnancy outcome of recurrent aborters.
    American journal of reproductive immunology (New York, N.Y.: 1989) 05/2001; 45(4):232-8. DOI:10.1111/j.8755-8920.2001.450406.x · 2.67 Impact Factor
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    ABSTRACT: Encapsulation of doxorubicin (Adriamycin) in liposome (LipADM) augments the anti-tumor effects of the drug and reduces side effects such as cardiotoxicity. However, it does not always enhance anti-tumor effects because of entrapment by the reticuloendothelial system. In this study, we investigated the anti-tumor effect of LipADM injected directly into the tumor to augment tumor targeting. LipADM (7.5 mg/kg body weight), the same concentration as free ADM (FADM), was injected percutaneously or i.v. into 7-day-old established Meth-A tumors in mice. Mock liposome was injected percutaneously into tumors of control mice. Mean relative tumor weights of the 5 groups on day 15 were as follows: intra-tumoral injection of LipADM, 2.92 +/- 1.09; intra-tumoral injection of FADM, 6.99 +/- 2.92; i.v. injection of LipADM, 11.07 +/- 7.95; i.v. injection of FADM, 11.80 +/- 6.55; control, 23.94 +/- 9.03. Mean survival times were as follows: intra-tumoral injection of LipADM, 46.2 +/- 11.0 days; FADM, 34.6 +/- 9.6 days; mock control, 30.2 +/- 4.8 days. Histological examination showed no tissue damage at the site of s.c. injection of LipADM. ADM concentrations in tumor tissues after intra-tumoral injection were persistently high in the LipADM-treated group. Our results indicate that direct injection of LipADM into the tumor is therapeutically useful by producing persistently high concentrations of ADM in the target tissue, with few local and systemic side effects.
    International Journal of Cancer 12/2000; 88(4):645-51. · 5.01 Impact Factor
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    ABSTRACT: Encapsulation of doxorubicin (Adriamycin) in liposome (LipADM) augments the anti-tumor effects of the drug and reduces side effects such as cardiotoxicity. However, it does not always enhance anti-tumor effects because of entrapment by the reticuloendothelial system. In this study, we investigated the anti-tumor effect of LipADM injected directly into the tumor to augment tumor targeting. LipADM (7.5 mg/kg body weight), the same concentration as free ADM (FADM), was injected percutaneously or i.v. into 7-day-old established Meth-A tumors in mice. Mock liposome was injected percutaneously into tumors of control mice. Mean relative tumor weights of the 5 groups on day 15 were as follows: intra-tumoral injection of LipADM, 2.92 ± 1.09; intra-tumoral injection of FADM, 6.99 ± 2.92; i.v. injection of LipADM, 11.07 ± 7.95; i.v. injection of FADM, 11.80 ± 6.55; control, 23.94 ± 9.03. Mean survival times were as follows: intra-tumoral injection of LipADM, 46.2 ± 11.0 days; FADM, 34.6 ± 9.6 days; mock control, 30.2 ± 4.8 days. Histological examination showed no tissue damage at the site of s.c. injection of LipADM. ADM concentrations in tumor tissues after intra-tumoral injection were persistently high in the LipADM-treated group. Our results indicate that direct injection of LipADM into the tumor is therapeutically useful by producing persistently high concentrations of ADM in the target tissue, with few local and systemic side effects. Int. J. Cancer 88:645–651, 2000. © 2000 Wiley-Liss, Inc.
    International Journal of Cancer 11/2000; 88(4):645 - 651. DOI:10.1002/1097-0215(20001115)88:4<645::AID-IJC20>3.0.CO;2-4 · 5.01 Impact Factor
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    ABSTRACT: Binding of beta(2)-glycoprotein I (beta(2)-GPI)-dependent anticardiolipin antibodies (aCL) derived from antiphospholipid syndrome (APS) is significantly reduced in aCL ELISA due to loss of the phospholipid (PL) binding property of beta(2)-GPI by plasmin treatment. In the present study, the treatment generated a nicked form of beta(2)-GPI and resulted in loss of antigenicity for the autoantibodies detected in ELISA, using an beta(2)-GPI directly adsorbed polyoxygenated carboxylated plate, the assay system of which was not related to PL binding. The nicked form bound to neither Cu(2+)-oxidized low-density lipoprotein (oxLDL) nor to beta(2)-GPI-specific lipid ligands isolated from oxLDL, the result being a complete loss of subsequent binding of anti-beta(2)-GPI autoantibodies. The conformational change in the nicked domain V was predicted from its intact structure determined by an X-ray analysis (implemented in Protein Data Bank: 1C1Z), molecular modeling and epitope mapping of a monoclonal anti-beta(2)-GPI antibody, i.e. Cof-18, which recognizes the related structure. The analysis revealed that novel hydrophobic and electrostatic interactions appeared in domain V after the cleavage, thereby affecting the PL binding of beta(2)-GPI. Such a conformational change may have important implications for exposure of cryptic epitopes located in the domains such as domain IV.
    International Immunology 09/2000; 12(8):1183-92. DOI:10.1093/intimm/12.8.1183 · 3.18 Impact Factor
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    ABSTRACT: When keratinocytes withdraw from the cell cycle, they migrate from the basal to the superficial layers of the epidermis and undergo morphological and biochemical changes during the process of terminal differentiation. These differentiation features of keratinocytes are known to be altered or reduced in esophageal cancer cells. Therefore, we examined the effects of transferring the cyclin-dependent kinase inhibitor p21sdi1 gene into human esophageal cancer cell lines as well as normal keratinocytes using an adenovirus vector system. Ectopic expression of p21sdi1 protein resulted in cell cycle arrest at the G1 phase and produced morphological changes, such as enlarged nuclei and a flattened cellular shape, changes specific to the differentiated phenotype. The human involucrin protein is a specific product of keratinocyte differentiation, which is selectively expressed in the suprabasal epidermal layers. Western blot analysis and immunohistochemical staining demonstrated that involucrin expression was 3- to 5-fold enhanced by the forced expression of p21sdi1 in esophageal cancer cells, whereas only a mild up-regulation up to 1.2-fold occurred in normal keratinocytes. We also found that exogenous introduction of the p2sdi1 gene transcriptionally activated the upstream promoter function of the involucrin gene. These stimulatory effects on involucrin expression were not observed when another cyclin-dependent kinase inhibitor gene, p16(INK4a), was transduced. Moreover, p21sdi1 expression in esophageal cancer cells transduced with p21sdi1 led to a rapid apoptotic cell death after a transient dormant phase, although keratinocytes transduced with p21sdi1 survived longer by terminally withdrawing from the cell cycle. These results may have an important implication for understanding the biology of differentiation-dependent apoptosis in human esophageal squamous cell carcinoma.
    Clinical Cancer Research 01/2000; 5(12):4233-41. · 8.19 Impact Factor
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    ABSTRACT: The transcription factor E2F coordinately activates several cell cycle-regulatory genes. We attempted to inhibit the proliferation of mesangial cells in vitro and in vivo by inhibiting E2F activity using a 25-bp decoy oligodeoxynucleotide that contained consensus E2F binding site sequence (E2F-decoy) as a competitive inhibitor. The decoy's effect on human mesangial cell proliferation was evaluated by [3H]thymidine incorporation. The E2F decoy inhibited proliferation in a concentration-dependent manner, whereas a mismatch control oligodeoxynucleotide had little effect. Electrophoretic mobility shift assays demonstrated that the decoy's inhibitory effect was due to the binding of the decoy oligodeoxynucleotide to E2F. The effect of the E2F decoy was then tested in a rat anti-Thy 1.1 glomerulonephritis model. The E2F decoy oligodeoxynucleotide was introduced into the left kidney 36 h after the induction of glomerulonephritis. The administration of E2F decoy suppressed the proliferation of mesangial cells by 71%. Furthermore, treatment with the E2F decoy inhibited the glomerular expression of proliferating cell nuclear antigen at the protein level as well as the mRNA level. These findings indicate that decoy oligonucleotides can suppress the activity of the transcription factor E2F, and may thus have a potential in treating glomerulonephritis.
    Journal of Clinical Investigation 07/1998; 101(11):2589-97. DOI:10.1172/JCI429 · 13.77 Impact Factor
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    ABSTRACT: Beta2-Glycoprotein I (beta2-GPI) is a major antigen for anticardiolipin antibodies (aCL) induced in patients with antiphospholipid syndrome and their antigenic epitopes are cryptic. The epitopes appear on the surface of beta2-GPI molecule only when beta2-GPI interacts with lipid membranes containing negatively charged phospholipids or polyoxygenated polystyrene surface. Our data also indicated that CuSO4-oxidized low density lipoproteins (oxLDL) are subsequently targeted by beta2-GPI and aCL; however, malonedialdehyde (MDA)-modified LDL were recognized neither by beta2-GPI nor aCL. Beta2-GPI binding to LDL was rapidly increased by incubation with CuSO4. Oxidation of lipoproteins was accompanied with the increment of thiobarbituric acid-reactive substances (TBARS) and denature of apolipoprotein. Ligands on LDL for beta2-GPI seemed to be intermediate oxidative derivatives which were extractable into the chloroform phase by Bligh and Dyer's extraction, but not MDA. Further, immune responses against beta2-GPI, as an anti-atherogenic protein, were demonstrated to induce atherogenic effect in in vitro oxLDL uptake by macrophages.
    Lupus 02/1998; 7 Suppl 2:S135-9. · 2.48 Impact Factor
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    ABSTRACT: β2-Glycoprotein I (β2-GPI) is a major antigen for anticardiolipin antibodies (aCL) induced in patients with antiphospholipid syndrome and their antigenic epitopes are cryptic. The epitopes appear on the surface of β2-GPI molecule only when β2-GPI interacts with lipid membranes containing negatively charged phospholipids or polyoxygenated polystyrene surface. Our data also indicated that CuSO4-oxidized low density lipoproteins (oxLDL) are subsequently targeted by β2- GPI and aCL; however, malonedialdehyde (MDA)-modified LDL were recognized neither by β2- GPI nor aCL. β2-GPI binding to LDL was rapidly increased by incubation with CuSO4. Oxidation of lipoproteins was accompanied with the increment of thiobarbituric acid-reactive substances (TBARS) and denature of apolipoprotein. Ligands on LDL for β2-GPI seemed to be intermediate oxidative derivatives which were extractable into the chloroform phase by Bligh and Dyer's extraction, but not MDA. Further, immune responses against β2-GPI, as an anti-atherogenic protein, were demonstrated to induce atherogenic effect in in vitro oxLDL uptake by macrophages.
    Lupus 01/1998; 7. DOI:10.1177/096120339800700230 · 2.48 Impact Factor