Publications (20)77.14 Total impact
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Article: Inhibition of connective tissue growth factor ameliorates rheumatoid arthritis in a murine model.
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ABSTRACT: (Objective): We have shown that connective tissue growth factor (CTGF) plays an important role in the pathogenesis of RA. Herein, we evaluated the effects of blockade of CTGF pathway on the development of arthritis in collagen-induced arthritis (CIA) mice. (Methods): Arthritis was induced in DBA/1J mice by immunization with a combination of type II collagen and complete Freund's adjuvant (CFA). We evaluated the efficacy of prevention of development of arthritis in the CIA mice treated with or without neutralizing anti-CTGF monoclonal antibody (mAb). (Results): Inhibition of the CTGF functions in mice treated with neutralizing anti-CTGF mAb significantly ameliorated arthritis compared to that in the non-treated CIA mice. Serum levels of matrix metalloproteinase 3 (MMP-3) were reduced by anti-CTGF mAb treatment. Moreover, blockade of the CTGF decreased interleukin 17 (IL-17) expression on purified CD4+ T lymphocytes. Although the expression of retinoic-acid-receptor-related orphan receptors γt (RORγt) gene was not suppressed by anti-CTGF mAb treatment, those of interferon regulatory factor 4 (IRF4) and IkappaBzeta (Nfkbiz), which are other important molecules for differentiation of Th-17 cells, were suppressed. In addition, blockade of CTGF inhibited pathological proliferation of T lymphocytes against type II collagen restimulation in vitro. Moreover, aberrant osteoclastogenesis in CIA mice was restored by anti-CTGF mAb treatment. (Conclusions): The present study showed that blockade of CTGF prevented progression of arthritis in CIA mice. Anti-CTGF mAb treatment suppressed the pathological T cells function and restored aberrant osteoclastogenesis in CIA mice. CTGF may become a new therapeutic target for treatment of RA. © 2013 American College of Rheumatology.Arthritis & Rheumatism 02/2013; · 7.87 Impact Factor -
Article: Serum proteome analysis in patients with rheumatoid arthritis receiving therapy with etanercept, a chimeric tumor necrosis factor-alpha receptor.
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ABSTRACT: Rheumatoid arthritis (RA) is a chronic inflammatory disorder of the synovium resulting in the destruction of affected joint cartilage and bone structures. Etanercept is a biological agent that blocks the tumor necrosis factor-α (TNF-α)-mediated inflammatory processes in RA patients, and has a regenerative effect on cartilage. In order to identify novel disease-related proteins and candidate biomarkers, we performed proteomic profiling of the serum in patients with RA who were treated with etanercept. Serum samples were obtained from eight RA patients before and after etanercept treatment. The low molecular weight proteins in the serum were concentrated and analyzed by liquid chromatography-tandem mass spectrometry. The results before and after etanercept treatment were compared by the spectrum count method. Among a total of 477 proteins identified, 12 were found to be decreased and five were increased by etanercept treatment. Some of the changed proteins were known to be related to RA, and most of the other changed proteins may play possible roles in the TNF-α signaling pathway or the state of cartilage and extracellular matrix. The present proteomic study identified several proteins that could be involved in the pathogenesis of RA. These findings could thus lead to the identification of novel candidate disease-related protein biomarkers for RA, or indicate new targets for therapy.International Journal of Rheumatic Diseases 10/2012; 15(5):486-95. · 0.81 Impact Factor -
Article: Anti-proteasome activator 28α is a novel anti-cytoplasmic antibody in patients with systemic lupus erythematosus and Sjögren’s syndrome
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ABSTRACT: We evaluated the extent to which anti-proteasome activator (PA) 28α antibodies act as anti-cytoplasmic antibodies in systemic lupus erythematosus (SLE) and Sjögren’s syndrome (SS). Sera from 46 SLE patients without SS, 11 SLE patients with SS, and 45 primary SS patients were tested. Using anti-PA28α and anti-PA28γ (Ki) antibodies purified from nitrocellulose membranes onto which recombinant PA28α and Ki had been transferred, the cellular distributions of the targeted antigens were analyzed immunohistochemically. In addition, the incidence of anti-PA28α antibodies was compared with those of other anti-cytoplasmic antibodies. Immunofluorescent staining showed that purified anti-PA28α antibodies reacted with the cytoplasm of HEp-2 cells, whereas purified anti-Ki antibodies reacted with nucleoplasm. Among the 15 SLE patients without SS, the six SLE patients with SS, and the 30 primary SS patients who were anti-cytoplasmic-antibody positive, anti-SS-A/Ro antibodies were the most frequently detected (53, 67, and 70%, respectively); anti-PA28α antibodies were, respectively, detected in 33, 50, and 40% of those patient groups, incidences that were higher than those of anti-ribosomal P, anti-smooth muscle and anti-mitochondrial M2 antibodies. These results show that anti-PA28α antibodies are major anti-cytoplasmic antibodies in patients with SLE and SS, and the distinct cellular distributions of PA28α and Ki suggest these proteins are associated with different cellular functions.Modern Rheumatology 04/2012; 19(6):622-628. · 1.58 Impact Factor -
Article: Anti-proteasome activator 28alpha is a novel anti-cytoplasmic antibody in patients with systemic lupus erythematosus and Sjögren's syndrome.
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ABSTRACT: We evaluated the extent to which anti-proteasome activator (PA) 28alpha antibodies act as anti-cytoplasmic antibodies in systemic lupus erythematosus (SLE) and Sjögren's syndrome (SS). Sera from 46 SLE patients without SS, 11 SLE patients with SS, and 45 primary SS patients were tested. Using anti-PA28alpha and anti-PA28gamma (Ki) antibodies purified from nitrocellulose membranes onto which recombinant PA28alpha and Ki had been transferred, the cellular distributions of the targeted antigens were analyzed immunohistochemically. In addition, the incidence of anti-PA28alpha antibodies was compared with those of other anti-cytoplasmic antibodies. Immunofluorescent staining showed that purified anti-PA28alpha antibodies reacted with the cytoplasm of HEp-2 cells, whereas purified anti-Ki antibodies reacted with nucleoplasm. Among the 15 SLE patients without SS, the six SLE patients with SS, and the 30 primary SS patients who were anti-cytoplasmic-antibody positive, anti-SS-A/Ro antibodies were the most frequently detected (53, 67, and 70%, respectively); anti-PA28alpha antibodies were, respectively, detected in 33, 50, and 40% of those patient groups, incidences that were higher than those of anti-ribosomal P, anti-smooth muscle and anti-mitochondrial M2 antibodies. These results show that anti-PA28alpha antibodies are major anti-cytoplasmic antibodies in patients with SLE and SS, and the distinct cellular distributions of PA28alpha and Ki suggest these proteins are associated with different cellular functions.Modern Rheumatology 09/2009; 19(6):622-8. · 1.58 Impact Factor -
Article: Congenital heart block not associated with anti-Ro/La antibodies: comparison with anti-Ro/La-positive cases.
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ABSTRACT: To study anti-Ro/La-negative congenital heart block (CHB). Forty-five fetuses with CHB were evaluated by analysis of anti-Ro/La antibodies using sensitive laboratory methods. There were 9 cases of anti-Ro/La-negative CHB; 3 died (33.3%). Only 3 (33.3%) were complete in utero and 5 (55.5%) were unstable. No specific etiology was diagnosed. Six infants (66.6%) were given pacemakers. There were 36 cases of anti-Ro/La-positive CHB. All except 2 infants (94.4%) had complete atrioventricular block in utero. Ten died (27.8%), one (2.7%) developed severe dilated cardiomyopathy, and 26 (72.2%) were given pacemakers. Nine of the 45 consecutive CHB cases (20%) were anti-Ro/La-negative with no known cause. They were less stable and complete than the anti-Ro/La positive cases.The Journal of Rheumatology 07/2009; 36(8):1744-8. · 3.69 Impact Factor -
Article: Autoantibody to NA14 is an independent marker primarily for Sjogren's syndrome.
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ABSTRACT: Nuclear Autoantigen of 14 kDa (NA14) was originally identified using the serum of a Sjögren's syndrome (SS) patient as probe in screening a human testis cDNA expression library. To date there is no report in the systematic analysis of the prevalence of autoantibodies to NA14. In this study, anti-NA14 was determined in several rheumatic diseases from independent cohorts in the US and Japan. The prevalence of anti-NA14 were 18/132 (13.6%) in primary SS, 0/50 (0%) secondary SS, 2/100 (2%) SLE, 1/43 (2.3%) scleroderma, 0/54 (0%) rheumatoid arthritis, 1/29 (3.4%) polymyositis/dermatomyositis, and 0/58 (0%) normal healthy controls. The frequencies of anti-NA14 positive sera in primary SS are statistically greater than normal healthy controls (p=0.006), secondary SS (p=0.044), and other rheumatic diseases. Furthermore, among 11 anti-NA14 positive primary SS sera, 4/11 (36.3%) sera were negative for both anti-SS-A/Ro and SS-B/La antibodies. Thus anti-NA14 autoantibodies may be useful for the discrimination of primary versus secondary SS and serve as a diagnostic marker for primary SS especially in seronegative (anti-SS-A/Ro and anti-SS-B/La antibodies negative) patients with SS.Frontiers in Bioscience 02/2009; 14:3733-9. · 3.52 Impact Factor -
Article: Differential anti-Golgi complex autoantibody production following murine lactate dehydrogenase-elevating virus infection.
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ABSTRACT: Lactate dehydrogenase-elevating virus (LDV) causes asymptomatic infection and persistent viremia in mice with unique infectious specificity directed to a certain subpopulation of macrophages leading to chronic infection and an immunological disorder that includes hyperimmunoglobulinemia and production of autoantibodies. Infection with a species of LDV originally isolated from mice carrying an LDV-contaminated transplantable tumor (LDV-W) was reported to induce anti-Golgi complex antibody (AGA) production. In contrast, infection with the most common LDV species (LDV-P) was not associated with AGA production. Here we performed the first independent side by side comparison of the effects of the two LDV strains on their hosts as an initial approach to investigating the production of AGA. After viral inoculation, both LDV-W and LDV-P infected mice exhibited similar changes in lactate dehydrogenase in plasma suggesting similar viral activity. However, AGA production was observed in only the LDV-W infected mice and these mice exhibited plasma IgG elevation and immune complex formation. These data validated the differential potential of LDV-W and LDV-P in the production of AGA. Future comparative characterizations in the immune processing of Golgi complex autoantigens using these viral strains may be useful in obtaining specific insights in the specific anti-Golgi complex autoimmune responses.Immunopharmacology and Immunotoxicology 02/2008; 30(1):13-25. · 1.83 Impact Factor -
Article: The role of GW/P-bodies in RNA processing and silencing.
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ABSTRACT: GW bodies, also known as mammalian P-bodies, are cytoplasmic foci involved in the post-transcriptional regulation of eukaryotic gene expression. Recently, GW bodies have been linked to RNA interference and demonstrated to be important for short-interfering-RNA- and microRNA-mediated mRNA decay and translational repression. Evidence indicates that both passenger and guide strands of short-interfering RNA duplexes can localize to GW bodies, thereby indicating that RNA-induced silencing complexes may be activated within these cytoplasmic centers. Formation of GW bodies appears to depend on both specific protein factors and RNA, in particular, microRNA. Work over the past few years has significantly increased our understanding of the biology of GW bodies, revealing that they are specialized cell components that spatially regulate mRNA turnover in various biological processes. The formation of GW bodies appears to depend on both specific protein factors and RNA, in particular, microRNA. Here, we propose a working model for GW body assembly in terms of its relationship to RNA interference. In this process, one or more heteromeric protein complexes accumulate in successive steps into larger ribonucleoprotein structures.Journal of Cell Science 04/2007; 120(Pt 8):1317-23. · 6.11 Impact Factor -
Article: Detection of the argonaute protein Ago2 and microRNAs in the RNA induced silencing complex (RISC) using a monoclonal antibody.
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ABSTRACT: MicroRNAs (miRNAs) are short RNA molecules responsible for post-transcriptional gene silencing by the degradation or translational inhibition of their target messenger RNAs (mRNAs). This process of gene silencing, known as RNA interference (RNAi), is mediated by highly conserved Argonaute (Ago) proteins which are the key components of the RNA induced silencing complex (RISC). In humans, Ago2 is responsible for the endonuclease cleavage of targeted mRNA and it interacts with the mRNA-binding protein GW182, which is a marker for cytoplasmic foci referred to as GW bodies (GWBs). We demonstrated that the anti-Ago2 monoclonal antibody 4F9 recognized GWBs in a cell cycle dependent manner and was capable of capturing miRNAs associated with Ago2. Since Ago2 protein is the effector protein of RNAi, anti-Ago2 monoclonal antibody may be useful in capturing functional miRNAs.Journal of Immunological Methods 01/2007; 317(1-2):38-44. · 2.20 Impact Factor -
Article: Nucleolar staining cannot be used as a screening test for the scleroderma marker anti-RNA polymerase I/III antibodies.
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ABSTRACT: Anti-RNA polymerase I/III (anti-RNAP I/III) antibodies are clinically useful markers of scleroderma, and their presence is associated with diffuse skin disease and an increased risk of cardiac and kidney involvement. Although RNAP I antibodies localize to the nucleolus, nucleolar staining by many anti-RNAP antibody-positive sera is not always observed. Nucleolar staining by anti-RNAP antibody-positive sera was examined by double staining with antifibrillarin antibodies to evaluate whether nucleolar staining can be used as a screening test for anti-RNAP I/III antibodies. In addition, the relationships between nucleolar staining and levels of anti-RNAP III antibodies were examined by enzyme-linked immunosorbent assay (ELISA) and immunoprecipitation (IP) assay. Sera were tested using immunofluorescent antinuclear antibodies on HEp-2 cell slides, by anti-RNAP III ELISA, and by IP assay using (35)S-labeled K562 cell extract. Nucleolar staining by anti-RNAP antibody IP-positive sera was confirmed by double staining using antifibrillarin monoclonal antibodies. The levels of anti-RNAP III antibodies were quantitated by ELISA and by IP assay using a serially diluted reference serum as a standard, and their relationship was analyzed. All 18 anti-RNAP I/III antibody-positive sera showed nuclear speckled patterns, but nucleolar staining was readily noticeable in only 44% of the sera. A positive correlation was found between ELISA and IP units for anti-RNAP III antibodies. The levels of anti-RNAP III antibodies and anti-RNAP I antibodies correlated well, with the exception of a few sera. Levels of anti-RNAP III antibodies were low in sera with nucleolar staining, whereas several sera with high levels of anti-RNAP I antibodies clearly showed nucleolar staining. Although some sera positive for anti-RNAP I/III antibodies clearly stain nucleoli, nucleolar staining is inconsistent and cannot be used to screen for anti-RNAP I/III antibodies.Arthritis & Rheumatism 10/2006; 54(9):3051-6. · 7.87 Impact Factor -
Article: Autoantibodies against the replication protein A complex in systemic lupus erythematosus and other autoimmune diseases.
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ABSTRACT: Replication protein A (RPA), a heterotrimer with subunits of molecular masses 70, 32, and 14 kDa, is a single-stranded-DNA-binding factor involved in DNA replication, repair, and recombination. There have been only three reported cases of anti-RPA in systemic lupus erythematosus (SLE) and Sjögren syndrome (SjS). This study sought to clarify the clinical significance of autoantibodies against RPA. Sera from 1,119 patients enrolled during the period 2000 to 2005 were screened by immunoprecipitation (IP) of 35S-labeled K562 cell extract. Antigen-capture ELISA with anti-RPA32 mAb, immunofluorescent antinuclear antibodies (ANA) and western blot analysis with purified RPA were also performed. Our results show that nine sera immunoprecipitated the RPA70-RPA32-RPA14 complex and all were strongly positive by ELISA (titers 1:62,500 to 1:312,500). No additional sera were positive by ELISA and subsequently confirmed by IP or western blotting. All sera showed fine speckled/homogeneous nuclear staining. Anti-RPA was found in 1.4% (4/276) of SLE and 2.5% (1/40) of SjS sera, but not in rheumatoid arthritis (0/35), systemic sclerosis (0/47), or polymyositis/dermatomyositis (0/43). Eight of nine patients were female and there was no racial predilection. Other positive patients had interstitial lung disease, autoimmune thyroiditis/hepatitis C virus/pernicious anemia, or an unknown diagnosis. Autoantibody specificities found in up to 40% of SLE and other diseases, such as anti-nRNP, anti-Sm, anti-Ro, and anti-La, were unusual in anti-RPA-positive sera. Only one of nine had anti-Ro, and zero of nine had anti-nRNP, anti-Sm, anti-La, or anti-ribosomal P antibodies. In summary, high titers of anti-RPA antibodies were found in nine patients (1.4% of SLE and other diseases). Other autoantibodies found in SLE were rare in this subset, suggesting that patients with anti-RPA may form a unique clinical and immunological subset.Arthritis research & therapy 02/2006; 8(4):R111. · 4.27 Impact Factor -
Article: Autoimmune targeting of key components of RNA interference.
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ABSTRACT: RNA interference (RNAi) is an evolutionarily conserved mechanism that is involved in the post-transcriptional silencing of genes. This process elicits the degradation or translational inhibition of mRNAs based on the complementarity with short interfering RNAs (siRNAs) or microRNAs (miRNAs). Recently, differential expression of specific miRNAs and disruption of the miRNA synthetic pathway have been implicated in cancer; however, their role in autoimmune disease remains largely unknown. Here, we report that anti-Su autoantibodies from human patients with rheumatic diseases and in a mouse model of autoimmunity recognize the human Argonaute (Ago) protein, hAgo2, the catalytic core enzyme in the RNAi pathway. More specifically, 91% (20/22) of the human anti-Su sera were shown to immunoprecipitate the full-length recombinant hAgo2 protein. Indirect immunofluorescence studies in HEp-2 cells demonstrated that anti-Su autoantibodies target cytoplasmic foci identified as GW bodies (GWBs) or mammalian P bodies, structures recently linked to RNAi function. Furthermore, anti-Su sera were also capable of immunoprecipitating additional key components of the RNAi pathway, including hAgo1, -3, -4, and Dicer. Together, these results demonstrate an autoimmune response to components of the RNAi pathway which could potentially implicate the involvement of an innate anti-viral response in the pathogenesis of autoantibody production.Arthritis research & therapy 02/2006; 8(4):R87. · 4.27 Impact Factor -
Article: Analysis of the Structure of Proteasome‐Proliferating Cell Nuclear Antigen (PCNA) Multiprotein Complex and Its Autoimmune Response in Lupus Patients
Annals of the New York Academy of Sciences 01/2006; 987(1):316 - 318. · 3.15 Impact Factor -
Article: Maternal antibody responses to the 52-kd SSA/RO p200 peptide and the development of fetal conduction defects.
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ABSTRACT: To identify a finer level of antibody specificity for risk of congenital heart block (CHB) than reactivity to 52-kd SSA/Ro (Ro 52). Serum from mothers enrolled in the Research Registry for Neonatal Lupus and the observational PR Interval and Dexamethasone Evaluation (PRIDE) study was evaluated for reactivity against peptide aa200-239 of Ro 52 (p200), recently reported to be associated with a higher risk of CHB. The majority of 156 Ro 52-positive sera tested were reactive with p200 (>3 SD above control), irrespective of the clinical status of the child. Optical density (OD) values of p200 did not differ significantly among mothers of children with CHB (mean +/- SD 0.187 +/- 0.363), mothers of children with rash (mean +/- SD 0.176 +/- 0.356), and mothers of children without neonatal lupus (mean +/- SD 0.229 +/- 0.315). Reactivity against p200 was found in 80 of 104 mothers of children with CHB (77%), 24 of 30 mothers of children with rash (80%), and 21 of 22 mothers who delivered healthy children and had no children with neonatal lupus (95%) (P not significant for all comparisons). Sera from 4 mothers of children with CHB with varied p200 titers (OD range 0.025-1.818) bound to the surface of non-permeabilized apoptotic, but not proliferating, human fetal cardiocytes. In 32 Ro 52-positive women who completed the PRIDE study (22 with no child with neonatal lupus, 7 with a child with CHB, and 3 with a child with rash) in whom p200 levels were determined during pregnancy, the correlation between level of p200 (OD range 0.000-1.170) and maximal fetal PR interval (range 115-168 msec) was not significant (rho = 0.107, P = 0.58). Reactivity to p200 is a dominant but not uniform anti-Ro 52 response in women whose children have CHB. Since exposure to this antibody specificity was observed with a similar frequency in children without CHB born to mothers with anti-Ro 52, additional factors are necessary to convert risk to disease expression.Arthritis & Rheumatism 10/2005; 52(10):3079-86. · 7.87 Impact Factor -
Article: Autoimmune response to proteins of proliferating cell nuclear antigen multiprotein complexes in patients with connective tissue diseases.
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ABSTRACT: To analyze the autoimmune response to the proliferating cell nuclear antigen (PCNA) multiprotein complex in patients with connective tissue diseases (CTD). The PCNA complex was purified by affinity chromatography using anti-PCNA monoclonal antibodies. Then 196 serum samples from patients with systemic lupus erythematosus (SLE) and 82 from patients with other CTD were tested for reactivity with the complex by immunoblotting. Of 196 SLE sera, 61 (31%) reacted with at least one component of the PCNA complex, and most reactive sera contained autoantibodies to several components of the complex. Autoantibodies to PCNA complex were less common in patients with other CTD, and most of their sera reacted only with one or a few proteins in the complex. Two out of 20 scleroderma sera reactive with 100, 85, and 70 kDa proteins in the PCNA complex also had autoantibodies to topoisomerase I (topo I) antibodies, which is an element of the complex. These findings suggest that the autoimmune response to the PCNA complex was specific for SLE. Anti-PCNA complex antibodies were associated with an increased serum level of PCNA detected by ELISA. The spreading of the autoimmune response to the elements of the complex was observed in parallel with the increased serum PCNA level when a series of sera from a lupus patient were tested longitudinally. In addition, anti-PCNA complex antibodies were significantly correlated with lupus erythematosus cells. The "antigen-drive" system may play a crucial role in inducing the autoimmune response to the PCNA complex in patients with SLE.The Journal of Rheumatology 12/2004; 31(11):2142-50. · 3.69 Impact Factor -
Article: Anticyclic citrullinated peptide antibodies in patients with mixed connective tissue disease.
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ABSTRACT: The clinical significance of anticyclic citrullinated peptide (CCP) antibodies in patients with mixed connective tissue disease (MCTD) was assessed. Altogether, 86 sera from MCTD patients, 96 from rheumatoid arthritis (RA) patients, 42 from systemic lupus erythematosus (SLE) patients, 23 from systemic sclerosis (SSc) patients, 21 from polymyositis/dermatomyositis (PM/DM) patients, and 17 from those with Sjögren's syndrome (SjS) were tested for anti-CCP antibodies using an enzyme-lined immunosorbent assay. Among the 96 RA patients, anti-CCP antibodies were detected in 85%, with the frequency being significantly higher than in MCTD, SLE, SSc, PM/DM, and SjS patients (9%, 14%, 13%, 14%, and 18%, respectively; P < 0.001). Among eight MCTD patients who fulfilled the diagnostic criteria for RA, only 50% had anti-CCP antibodies, and the prevalence was significantly lower than for all RA patients (p < 0.01). All eight patients who fulfilled the criteria for RA had overlap of SLE and SSc, except one patient, whereas the four anti-CCP-positive patients who did not fulfill the criteria for RA had SjS without overlapping features of SLE and SSc; moreover, most of their antibody titers were low. These results suggested that anti-CCP antibodies are associated with RA in MCTD patients, but careful diagnosis of RA is required if patients with low titers of anti-CCP antibodies lack overlapping SLE and SSc.Modern Rheumatology 01/2004; 14(5):367-75. · 1.58 Impact Factor -
Article: Clinical significance of antibodies to TS1-RNA in patients with mixed connective tissue disease.
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ABSTRACT: To investigate the clinical significance of anti-TS1-RNA antibodies in patients with mixed connective tissue disease (MCTD). Anti-TS1-RNA antibodies were detected by immunoprecipitation using 32P-UTP labeled TS1-RNA as the antigen source. In total, 104 patients with MCTD, 30 with Sjögren's syndrome, 30 with systemic lupus erythematosus (SLE), 25 with systemic sclerosis, 23 with polymyositis or dermatomyositis, and 10 with rheumatoid arthritis were examined. Specificity of anti-TS1-RNA antibodies was analyzed by immunoprecipitation using HeLa cell extracts. The frequency of anti-TS1-RNA antibodies was 31.7% in patients with MCTD, significantly higher than in SLE (p < 0.05). In anti-TS1-RNA positive patients, the incidence of hypertension and proteinuria and the frequency of anti-Sm and anti-dsDNA antibodies associated with SLE were higher than those of anti-TS1-RNA negative patients. Clinical features of SS such as sicca complex, the serum level of IgA, and anti-SSA antibodies were also elevated. The frequency of anti-TS1-RNA antibodies was significantly higher in SLE patients with anti-U1-RNP antibodies (p < 0.01); however, anti-TS1-RNA positive sera did not precipitate the specific RNA including U1 RNA in immunoprecipitation using HeLa cell extracts. In longitudinal studies, the level of anti-TS1-RNA antibodies changed in parallel with disease activity. We found that the level of anti-TS1-RNA antibodies was possibly correlated with the disease activity of lupus-like clinical features in patients with MCTD.The Journal of Rheumatology 05/2003; 30(5):998-1005. · 3.69 Impact Factor -
Article: Autoimmune responses to proliferating cell nuclear antigen multiprotein complexes involved in cell proliferation are strongly associated with their structure and biologic function in patients with systemic lupus erythematosus.
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ABSTRACT: To analyze the reaction of lupus sera with proliferating cell nuclear antigen (PCNA) multiprotein complexes (PCNA complexes), which are part of the protein machinery involved in cell proliferation. PCNA complexes were purified from rabbit thymus extract by affinity chromatography using anti-PCNA monoclonal antibodies (TOB7, TO17, and TO30); monomeric and trimeric PCNA forms (AK-PCNA) were purified using anti-PCNA serum AK. The reactions to these antigens of 10 anti-PCNA-positive and 40 anti-PCNA-negative sera selected from 560 lupus patients were tested by immunoblotting, immunoprecipitation, and enzyme-linked immunosorbent assays (ELISAs). With one exception (serum OK), anti-PCNA-positive sera reacted exclusively with only the 34-kd polypeptide. In contrast, 14 of 40 anti-PCNA-negative sera reacted with multiple proteins within PCNA complexes. Most anti-PCNA-positive sera probably recognize as epitopes the binding sites for other proteins on PCNA, which are likely hidden when PCNA is complexed with other proteins. As a consequence, only serum OK reacted with the PCNA complex in a series of ELISAs. Using AK-PCNA as a competitive inhibitor, it was determined that serum OK reacts with both the 58-kd polypeptide and the 34-kd PCNA within complexes. Together with the results of a longitudinal analysis, these results suggest that the immune system of patient OK likely recognized the complexed PCNA protein, after which the autoimmune response spread to other elements of the complexes. Intermolecular-intrastructural help, leading to the spread of autoimmune response from PCNA to other proteins associated with its biologic function, plays a crucial role in the induction of the autoimmune response seen in lupus patients.Arthritis & Rheumatism 12/2002; 46(11):2946-56. · 7.87 Impact Factor -
Article: Anti-TS1-RNA: characterization of novel antibodies against sequence-specific RNA by random RNA selection in patients with Sjögren's syndrome.
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ABSTRACT: To define a novel RNA epitope recognized by serum from a patient with Sjögren's syndrome (SS) from a randomized RNA epitope library and investigate the epitope reactivity of the anti-RNA antibodies in patients with various connective tissue diseases. Serum from a patient with SS was used to select ligands from a library of RNA oligomers with a central region of 25 degenerate nucleotides. Bound RNA was recovered by reverse transcription, PCR amplification, and subcloning. The relationship between the antibodies to the selected RNA and disease specificity was studied using immunoprecipitation. From the random RNA library, several unique RNA sequences were obtained. Sera from 32 of 61 patients with SS (52.5%) precipitated with one of the selected RNA (TS1-RNA), whereas sera from 8 of 41 patients with systemic lupus erythematosus (19.5%) and 3 of 25 patients with rheumatoid arthritis (12.0%) precipitated. Although the frequency of reactivity to the TS1-RNA was higher in anti-SSA/Ro positive sera, the presence of either native or recombinant SSA/Ro antigen showed no detectable competition, and no apparent sequence homology was found between the TS1-RNA and hY RNA. These data suggest that anti-TS1-RNA is a novel antibody against sequence-specific RNA in many patients with SS.The Journal of Rheumatology 06/2002; 29(5):931-7. · 3.69 Impact Factor -
Article: Detection of the argonaute protein Ago2 and microRNAs in the RNA induced silencing complex (RISC) using a monoclonal antibody
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ABSTRACT: MicroRNAs (miRNAs) are short RNA molecules responsible for post-transcriptional gene silencing by the degradation or translational inhibition of their target messenger RNAs (mRNAs). This process of gene silencing, known as RNA interference (RNAi), is mediated by highly conserved Argonaute (Ago) proteins which are the key components of the RNA induced silencing complex (RISC). In humans, Ago2 is responsible for the endonuclease cleavage of targeted mRNA and it interacts with the mRNA-binding protein GW182, which is a marker for cytoplasmic foci referred to as GW bodies (GWBs). We demonstrated that the anti-Ago2 monoclonal antibody 4F9 recognized GWBs in a cell cycle dependent manner and was capable of capturing miRNAs associated with Ago2. Since Ago2 protein is the effector protein of RNAi, anti-Ago2 monoclonal antibody may be useful in capturing functional miRNAs.Journal of Immunological Methods.
Top co-authors
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Institutions
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2002–2012
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Juntendo University
- Institute for Environmental and Gender Specific Medicine
Tokyo, Tokyo-to, Japan
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2007
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University of Florida
- Department of Oral Biology
Gainesville, FL, USA
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