Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0036421 (PSS)
 10,989 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Autoantibody reactivity to centromere proteins CENP-A, CENP-B and CENP-C was examined in 58 patients with systemic sclerosis (SSc), 218 first degree relatives and 22 spouses. HLA class II typing for HLA-DRB1 and HLA-DQA1 was performed by restriction fragment length polymorphism (RFLP) analysis in 50 families, and HLA-DRB1, HLA-DQA1 and HLA-DQB1 typing was performed by olignucleotide typing in 44 families. Eleven probands and two relatives had ACA. The two relatives with ACA also had SSc. One relative was an identical twin sister of a proband with ACA and the other relative was a sister of a proband with ACA. All ACA-positive probands and relatives were female, and all recognized CENP-A, CENP-B and CENP-C. The presence of at least one HLA-DQB1 allele not coding for leucine at position 26 of the first domain appeared necessary, although not sufficient for the generation of ACA. Therefore within SSc families ACA is strongly associated with female gender and disease phenotype, and is at least in part genetically determined.
 ...
PMID:Anti-centromere antibodies (ACA) in systemic sclerosis patients and their relatives: a serological and HLA study. 818 34

The Western or protein blot has proven to be a valuable resource in detecting discrete, immunoreactive antigen targets associated with a variety of autoimmune diseases. As the roster of autoantigens has expanded, it has become increasingly common to tailor specific gel or blot conditions to a particular polypeptide antigen. Two such assays are reported here as applied to the fractionation and visualization of human centromere protein (CENP-A), a centromere autoantigen associated with the rheumatic disease, systemic sclerosis. The centromere antigens are effectively solubilized in the presence of 1 M MgCl2 to allow for further purification. CENP-A copurifies with the histone proteins, primarily H3 and H4. The two CENP-A-specific protein blot assays separate CENP-A from the histone proteins and enhance CENP-A immunoreactivity. The first assay is based on the use of acid-urea gels with a Triton X-100 concentration chosen to maximize separation of CENP-A from all the histones. The second assay is based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis to differentiate two very basic proteins of similar molecular weight, namely CENP-A and histone H3. For each gel system, a selective choice of associated immunoblot parameters allows for the reproducible discrimination of the CENP-A antigen.
 ...
PMID:Protein blot assays specific for the discrimination of the centromere autoantigen, CENP-A, from human cells. 822

Previous cytogenetic studies of patients with systemic sclerosis have obtained conflicting results regarding the presence of chromosomal anomalies. We studied 38 patients and 15 controls to determine whether these inconsistencies were due to differences in the subgroups of patients who were studied. Because many patients with systemic sclerosis produce autoantibodies to protein antigens that have been implicated in chromosome structure and function, we further hypothesized that the presence of these autoantibodies might correlate with the presence of chromosomal anomalies. Patients were classified into clinical subgroups based on the extent of their disease. Their sera were assayed for autoantibodies to topoisomerase I and centromere proteins (CENP-A, CENP-B, and CENP-C) by immunoblotting. Cytogenetic analyses for aneuploidy and chromosome breaks were performed. Anticentromere antibody positive (ACA+) patients had significantly more aneuploidy than either ACA negative (ACA-) patients or controls (P = 0.041). Although the patient group, when considered as a whole, had significantly greater aneuploidy than the control group (P < 0.005), patients who were ACA--did not have more aneuploidy than the controls had. Patients with Type I disease (sclerodactyly), the majority of whom were ACA+, also had significantly more aneuploidy than did either the controls or patients with Type III (diffuse) disease, most of whom were ACA- (P < 0.005). ACA+ patients also had more chromatid breaks than the controls had (P < 0.05). The correlation between the presence of ACAs and chromosomal aneuploidy suggests that aneuploidy may be the result of nondisjunction secondary to centromeric dysfunction. In support of this hypothesis, the ACA+ patients who had antibodies to CENP-C exhibited more chromosomal aneuploidy than did either anti-CENP-A or anti-CENP-B positive patients (P < 0.048). Unlike CENP-A and CENP-B, which are present at both functional and inactivated centromeres, CENP-C is present at the kinetochore of functional centromeres.
 ...
PMID:Cytogenetic survey in systemic sclerosis: correlation of aneuploidy with the presence of anticentromere antibodies. 838 18

Anticentromere antibodies (ACA) are associated with systemic sclerosis (scleroderma) patients exhibiting the more benign or so called limited manifestation of the disease (lSSc). ACA reactivity is directed against multiple polypeptide targets, the smallest of which is designated CENP-A. CENP-A is not an abundant cellular constituent; therefore to maximize recovery, we developed a protocol with a minimum of steps to isolate CENP-A from a human cell line. The trace cellular amount of this protein clearly dictated the production of its recombinant counterpart to facilitate determination of the role of the CENP-A antigen in scleroderma pathogenesis. Here we describe the eukaryotic expression of CENP-A cDNA using baculovirus-mediated infection of insect cells. The non-fusion recombinant protein spans the natural residues of the human CENP-A protein and rCENP-A followed the same chromotographic sequence for purification as did the natural source. The availability of the bona fide antigen provided a critical standard upon which to document authenticity of the recombinant polypeptide. The two forms of this antigen have been compared and shown to exhibit similar physical and antigenic properties.
 ...
PMID:Isolation and comparison of natural and recombinant human CENP-A autoantigen. 987 83

Centromere protein CENP-A is a histone H3-like protein associated specifically with the centromere and represents one of the human autoantigens identified by sera taken from patients with the CREST variant of progressive systemic sclerosis. Injection of whole human autoimmune serum to the centromere into interphase cells disrupts some mitotic events. It has been assumed that this effect is due to CENP-E and CENP-C autoantigens, because of the effects of injecting monospecific sera to those proteins into culture cells. Here we have used an antibody raised against an N-terminal peptide of the human autoantigen CENP-A to determine its function in mitosis and during cell cycle progression. Affinity-purified anti-CENP-A antibodies injected into the nucleus during the early replication stages of the cell cycle caused cells to arrest in interphase before mitosis. These cells showed highly condensed small nuclei, a granular cytoplasm and loss of their division capability. On the other hand, microinjection of nocodazole-blocked HeLa cells in mitosis resulted in the typical punctate staining pattern of CENP-A for centromeres during different stages of mitosis and apparently normal cell division. This was corroborated by time-lapse imaging microscopy analysis of mid-interphase-injected cells, revealing that they undergo mitosis and divide properly. However, a significant delay throughout the progression of mitotic stages was observed. These results suggest that CENP-A is involved predominantly in an essential interphase event at the centromere before mitosis. This may include chromatin assembly at the kinetochore coordinate with late replication of satellite DNA to form an active centromere.
 ...
PMID:Microinjection of antibodies to centromere protein CENP-A arrests cells in interphase but does not prevent mitosis. 991 71

Antibodies directed against an epitope motif on CENP-A have been shown to cross-react with mimotopes on other autoantigens and on Epstein-Barr nuclear antigen 1 (EBNA-1), suggesting a molecular mimicry. We describe here the gradual development of an anticentromere immune response in a patient with systemic sclerosis, which started from an antihistone response and was not mediated by molecular mimicry. Via an epitope on histone H3, the antibody response spread to a homologous epitope in the H3 homology domain of CENP-A. This was followed by an intramolecular epitope spreading to N-terminal peptides of CENP-A containing the known epitope motif G-P-X(1)-R-X(2). From there it spread to corresponding epitopes on CENP-B and to mimotopes of the major CENP-A epitope motif on other autoantigens including EBNA-1. Whether the D-penicillamine treatment received by this patient was involved in the triggering of this cascade remains a matter of speculation.
 ...
PMID:Development of a CENP-A/CENP-B-specific immune response in a patient with systemic sclerosis. 1212 71

Autoantibodies to the centromere proteins (CENP), which are major constituents of the primary constriction of metaphase chromosomes, were first described in 1980. In those seminal publications and 30 years of research that have followed, a number of CENP have been identified as autoantibody targets in human diseases. Historically, autoantibodies directed to CENP-A, -B and -C have been considered relatively specific biomarkers for limited cutaneous systemic sclerosis (lcSSc) or the calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasia (CREST) syndrome. These autoantibodies, found in up to 40% of SSc sera, can be identified by indirect immunofluorescence (IIF) on a variety of tissue culture cell lines as a discrete speckled staining pattern of both interphase nuclei and metaphase chromatin. Early in the investigation of anti-CENP, it became apparent that some autoantibodies had a similar IIF pattern wherein as cells entered into the cell cycle, speckled staining of the metaphase chromatin could be observed but, unlike conventional CENP staining, interphase nuclei were not stained. Subsequent studies identified one of the targets of these autoantibodies to be CENP-F, a kinesin binding protein essential for completion of the cell cycle. Early clinical studies found that, unlike antibodies to the earlier described CENP, lcSSc rarely expressed anti-CENP-F and approximately 50% of these patients had a malignancy. This review provides a historical perspective of CENP autoantibodies and focuses on an update of the information on CENP-F and their clinical associations.
 ...
PMID:Historical perspectives on the discovery and elucidation of autoantibodies to centromere proteins (CENP) and the emerging importance of antibodies to CENP-F. 2093 14

Systemic sclerosis (SSc) is a heterogeneous autoimmune disorder characterized by microvascular injury, fibrosis of the skin and other organs, and presence of antinuclear autoantibodies (ANA) with a prevalence varying from 80 to 98%. The ANA classically detected in SSc include anti-centromere (ACA) and anti-topoisomerase I (ATA), which are positive in 50-60% of the patients. Even if other autoantibodies, such as anti-fibrillarin (AFA), anti-RNA polymerase III (RNAP III), anti-PMScl, anti-Th/To, and anti-hUF/NOR-90, are almost specific for SSc, until recently they were not routinely looked for, since the techniques for their identification were not suitable for routine use. In recent years, the advances in the knowledge of the biochemistry and of the immunoreactive sites of the autoantigens led to the development of new immunoassays using recombinant proteins as autoantigens. We evaluated a new multiplex line immunoblot assay (LIA) for the simultaneous detection of 13 different SSc-associated autoantibodies, in a cohort of 210 SSc Italian patients. The sensitivity and the specificity of this assay were as follows: 30.5% and 97.3% for ACA (anti-CENP-B), 29.5% and 96% for ACA (anti-CENP-A), 20% and 99.3% for ATA, 5.7% and 99.3% for anti-RNAP III (RP-155), 5.2% and 100% for anti-RNP III (RP-11), 6.7% and 98% for anti-PMScl (PMScl-100), 10.9% and 93.3% for anti-PMScl (PMscl-75), 3.3% and 98.7% for anti-Th/To, 0.48% and 100% for AFA, 4.8% and 96.7% for anti-hUF/NOR-90, 4.7% and 96% for anti-Ku, 0.95% and 100% for anti-Platelet-Derived Growth Factor Receptor, and 18.1% and 50% for anti-Ro-52, respectively. These results, which are similar to those obtained in other studies using traditional techniques, show that the LIA assay can be considered a more rapid and a more practical method than immunoprecipitation assays for studying SSc-related antibodies in the diagnostic work-up of SSc patients.
 ...
PMID:Diagnostic accuracy and predictive value of extended autoantibody profile in systemic sclerosis. 2277 84

The autoantibody profiles in New Zealand systemic sclerosis patients have not previously been reported. The aim of this study was to evaluate the autoantibody profiles of patients in the Waikato Hospital Systemic Sclerosis Clinic cohort. The EUROLINE (IgG) Systemic Sclerosis panel test kit (which tests for Scl-70, CENP-A, CENP-B, RP11, RP155, Fib, NOR90, Th/To, PM100, PM75, Ku, PDGFR and Ro-52) was selected for the purpose of this study. All patients attending the Waikato Hospital Systemic Sclerosis clinic were invited to participate. These patients were categorised by systemic sclerosis subtypes [1]. Results were compared with previously published data, including the EUSTAR database. Sixty patients (56 female) were recruited, with a median age of 61 years (range 29-81 years). Forty-one had limited cutaneous systemic sclerosis (lcSSc). Of these lcSSc patients, 31 (75.6%) were positive for CENP-A and CENP-B (anti-centromere) antibodies, 12 (29.3%) for Ro-52 antibodies, 5 (12.2%) for RP11 and RP155, 4 (9.8%) for Scl-70 and 1 (2.4%) each for anti-Fib and Th/To antibodies. Fifteen patients had diffuse cutaneous systemic sclerosis (dcSSc), of which 7 patients (47.6%) were positive for RP11 and RP155, 4 (26.7%) for Scl-70. Three dcSSc patients did not have either of these two major antibodies, but of these 15 dcSSc patients, 4 patients (26.7%) were positive also for Ro-52, 2 (13.3%) for anti-Ku, and 1 (6.7%) each for anti-Fib and NOR90. Four patients had overlap syndrome (OLS), 1 had CENP-A and CENP-B antibodies, 1 had Ro-52 autoantibodies 1 had anti-Ku antibodies. Three patients had no autoantibodies. This is the first study to look at the autoantibody profile of SSc patients in New Zealand. A higher prevalence of antibodies against centromere and RNA polymerase III was demonstrated in our group compared with the EUSTAR database suggesting that antibody prevalence may vary geographically.
 ...
PMID:A cross-sectional study of autoantibody profiles in the Waikato systemic sclerosis cohort, New Zealand. 2602 20

Systemic sclerosis (SSc) is systemic, autoimmune, connective tissue disorder characterized by vascular abnormalities, collagen deposition (fibrosis), and the production of autoantibodies to nuclear proteins. About 20%-40% of patients have antibodies to centromere protein (CENP)-A or -B. Despite the known association of anti-CENP antibodies with certain clinical features of SSc, the role of these antibodies in SSc physiopathology is still poorly understood. To better understand the clinical significance and origin of these antibodies, we and others have been studying the epitopic motifs (amino acid contact sites) on CENP-A with the aim of determining whether other proteins can prime or be targeted by them. Here, we review published and ongoing studies aimed at defining the fine specificity and origin of anti-CENP-A antibodies. We describe progress made in identifying the CENP-A epitopic motif amino acids, and the discovery of one of these motifs in forkhead box protein E3 (FOXE-3), a transcription factor previously studied only for its role in the development of lens fiber cells. Moreover, we discuss preliminary evidence for a possible role of FOXE-3 in SSc pathogenesis and for the association of different subsets of anti-CENP-A antibodies, heterogeneously expressed among SSc patients, with some clinical correlates.
...
PMID:Anti-centromere protein A antibodies in systemic sclerosis: Significance and origin. 2645 61


1 2 Next >>