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Biomedical subjects

Shunsei Hirohata

Publications and source records attributed to Shunsei Hirohata.

At least 19 recordsLinked to original sources
PubMed2006

Enhanced expression of mRNA for nuclear factor kappaB1 (p50) in CD34+ cells of the bone marrow in rheumatoid arthritis.

Bone marrow CD34+ cells from rheumatoid arthritis (RA) patients have abnormal capacities to respond to tumor necrosis factor (TNF)-alpha and to differentiate into fibroblast-like cells producing matrix metalloproteinase (MMP)-1. We explored the expression of mRNA for nuclear factor (NF)kappaB in RA bone marrow CD34+ cells to delineate the mechanism for their abnormal responses to TNF-alpha. CD34+ cells were purified from bone marrow samples obtained from 49 RA patients and 31 osteoarthritis (OA) patients during joint operations via aspiration from the iliac crest. The mRNAs for NFkappaB1 (p50), NFkappaB2 (p52) and RelA (p65) were examined by quantitative RT-PCR. The expression of NFkappaB1 mRNA in bone marrow CD34+ cells was significantly higher in RA than in OA, whereas there was no significant difference in the expression of mRNA for NFkappaB2 and RelA. The expression of NFkappaB1 mRNA was not correlated with serum C-reactive protein or with the treatment with methotrexate or oral steroid. Silencing of NFkappaB1 by small interfering RNA abrogated the capacity of RA bone marrow CD34+ cells to differentiate into fibroblast-like cells and to produce MMP-1 and vascular endothelial growth factor upon stimulation with stem cell factor, granulocyte-macrophage colony stimulating factor and TNF-alpha without influencing their viability and capacity to produce beta2-microglobulin. These results indicate that the enhanced expression of NFkappaB1 mRNA in bone marrow CD34+ cells plays a pivotal role in their abnormal responses to TNF-alpha and, thus, in the pathogenesis of RA.

Adult↗
PubMed2006

Accuracy of anti-ribosomal P protein antibody testing for the diagnosis of neuropsychiatric systemic lupus erythematosus: an international meta-analysis.

OBJECTIVE: To quantitatively evaluate the diagnostic accuracy of antibodies to ribosomal P proteins (anti-P) for neuropsychiatric systemic lupus erythematosus (NPSLE) in general, for psychosis, mood disorder, or both, and for other diffuse manifestations. METHODS: This international meta-analysis combined standardized data from 1,537 lupus patients contributed by 14 research teams. Weighted estimation of sensitivity and specificity with fixed-effects and random-effects models, as well as summary receiver operating characteristic (SROC) curve analysis, was used to summarize test performance. The robustness of the overall estimates was examined in sensitivity analyses that included additional studies published up to November 1, 2004 in the Medline, EMBase, and Cochrane databases. RESULTS: Combining the data from the 14 teams, the weighted sensitivity and specificity estimates for the diagnosis of NPSLE were 26% (95% confidence interval [95% CI] 15-42%) and 80% (95% CI 74-85%), respectively. For psychosis, mood disorder, or both, the sensitivity and specificity were 27% (95% CI 14-47%) and 80% (95% CI 74-85%), respectively. For other diffuse manifestations, the sensitivity was 24% (95% CI 12-42%), and the specificity was 80% (95% CI 73-85%). The proportion of patients with anti-P antibodies did not vary markedly across different presentations of NPSLE. Between-study heterogeneity was substantial, but the SROC curves were consistent with the weighted estimates. In further analyses that included another 24 published studies, only the sensitivity for psychosis and/or mood disorder was slightly improved, but it was still suboptimal (42% [95% CI 30-53%]); the specificity remained essentially the same (81% [95% CI 76-85%]). CONCLUSION: Anti-P antibody testing has limited diagnostic value for NPSLE, and it is not helpful in differentiating among various disease phenotypes.

Antibodies↗
PubMed2005

Inhibition of CX3CL1 (fractalkine) improves experimental autoimmune myositis in SJL/J mice.

Idiopathic inflammatory myopathy is a chronic inflammatory muscle disease characterized by mononuclear cell infiltration in the skeletal muscle. The infiltrated inflammatory cells express various cytokines and cytotoxic molecules. Chemokines are thought to contribute to the inflammatory cell migration into the muscle. We induced experimental autoimmune myositis (EAM) in SJL/J mice by immunization with rabbit myosin and CFA. In the affected muscles of EAM mice, CX3CL1 (fractalkine) was expressed on the infiltrated mononuclear cells and endothelial cells, and its corresponding receptor, CX3CR1, was expressed on the infiltrated CD4 and CD8 T cells and macrophages. Treatment of EAM mice with anti-CX3CL1 mAb significantly reduced the histopathological myositis score, the number of necrotic muscle fibers, and infiltration of CD4 and CD8 T cells and macrophages. Furthermore, treatment with anti-CX3CL1 mAb down-regulated the mRNA expression of TNF-alpha, IFN-gamma, and perforin in the muscles. Our results suggest that CX3CL1-CX3CR1 interaction plays an important role in inflammatory cell migration into the muscle tissue of EAM mice. The results also point to the potential therapeutic usefulness of CX3CL1 inhibition and/or blockade of CX3CL1-CX3CR1 interaction in idiopathic inflammatory myopathy.

Animals↗
PubMed2005

Anti-ribosomal P protein antibody in human systemic lupus erythematosus up-regulates the expression of proinflammatory cytokines by human peripheral blood monocytes.

OBJECTIVE: Autoantibodies to ribosomal P proteins (anti-P antibodies) are detected in 12-16% of patients with systemic lupus erythematosus (SLE) and have been found to be associated with some manifestations of the disease, including lupus psychosis and hepatitis. Recent studies have disclosed that anti-P antibodies react with activated T cells but not with B cells, suggesting possible direct effects of anti-P antibodies on immune regulation. The present study was designed to explore the presence of the epitope recognized by anti-P antibodies on human peripheral blood monocytes. METHODS: Highly purified peripheral blood monocytes obtained from healthy donors were cultured with or without interferon-gamma (IFNgamma) in the presence of either anti-P antibodies purified by affinity chromatography from the sera of patients with SLE or control IgG. RESULTS: Flow cytometry analysis disclosed that fresh (day 0) monocytes did not express the ribosomal P epitope, whereas expression of the ribosomal P epitope was induced on annexin V-negative monocytes after activation through plastic adherence for 48 hours. More important, anti-P antibodies (compared with normal IgG or IgG from SLE patients devoid of anti-P antibodies) enhanced the production of tumor necrosis factor alpha (TNFalpha) and interleukin-6 (IL-6) by activated monocytes. Accordingly, anti-P antibodies also up-regulated the expression of TNFalpha and IL-6 messenger RNA in activated monocytes. Of note, F(ab')(2) fragments of anti-P antibodies, which do not result in Fcgamma receptor (FcgammaR) crosslinking, also effectively up-regulated the expression of TNFalpha and IL-6. CONCLUSION: These results indicate that human peripheral blood monocytes express the ribosomal P epitope upon activation, irrespective of induction of apoptosis. Moreover, the data suggest that anti-P antibodies might modify a variety of inflammatory responses through up-regulation of the expression of proinflammatory cytokines in monocytes, in a manner that does not involve FcgammaR crosslinking.

Autoantibodies↗
PubMed2005

Elevated levels of soluble fractalkine in active systemic lupus erythematosus: potential involvement in neuropsychiatric manifestations.

OBJECTIVE: To determine levels of the soluble form of the chemokine fractalkine (sFkn) and its receptor, CX(3)CR1, in patients with systemic lupus erythematosus (SLE) with neuropsychiatric involvement (NPSLE) and in SLE patients without neuropsychiatric involvement, and to assess their relationship with disease activity and organ damage. METHODS: Levels of sFkn in serum and cerebrospinal fluid (CSF) were measured by enzyme-linked immunosorbent assay. Expression of Fkn and CX(3)CR1 was quantified using real-time polymerase chain reaction. Surface expression of CX(3)CR1 on peripheral blood mononuclear cells (PBMCs) was determined by flow cytometry. Disease activity and organ damage were assessed using the SLE Disease Activity Index (SLEDAI) and the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) Damage Index, respectively. RESULTS: Serum sFkn levels were significantly higher in patients with SLE than in patients with rheumatoid arthritis (RA) or healthy controls. In addition, significant correlations between serum sFkn levels and the SLEDAI, the SLICC/ACR Damage Index, anti-double-stranded DNA and anti-Sm antibody titers, immune complex levels (C1q), and serum complement levels (CH50) were observed. Expression of CX(3)CR1 was significantly greater in PBMCs from patients with active SLE than in those from RA patients or healthy controls. Levels of sFkn were also significantly higher in CSF from untreated patients with newly diagnosed NPSLE than in SLE patients without neuropsychiatric involvement; treatment reduced both serum and CSF levels of sFkn in patients with SLE. CONCLUSION: Soluble Fkn and CX(3)CR1 may play key roles in the pathogenesis of SLE, including the neuropsychiatric involvement. Soluble Fkn is also a serologic marker of disease activity and organ damage in patients with SLE, and its measurement in CSF may be useful for the diagnosis of NPSLE and followup of patients with NPSLE.

Adult↗
PubMed2005

Differential effects of IFN-alpha on the expression of various TH2 cytokines in human CD4+ T cells.

BACKGROUND: In both human subjects and mice, T helper cells are classified into 2 subsets, TH1 and TH2 cells, on the basis of the cytokines they produce. Although IFN-alpha has been shown to enhance human TH1 responses, its influences on human TH2 responses have not yet been fully characterized. In addition, the mechanism for induction of TH1 responses by IFN-alpha has not been fully delineated. OBJECTIVE: The present study was undertaken to explore the direct effects of IFN-alpha on the expression of various cytokines in human CD4+ T cells with a system using immobilized anti-CD3, which permits activation of CD4+ T cells in the complete absence of accessory cells. METHODS: Highly purified CD4+ T cells obtained from healthy donors were stimulated with immobilized anti-CD3 with or without IFN-alpha and IL-12 in the complete absence of accessory cells. The production of cytokines was estimated by means of ELISA. The expression of mRNA for various cytokines, as well as transcription factors, was evaluated by using quantitative PCR. RESULTS: IFN-alpha enhanced IL-4 protein and mRNA expression in immobilized anti-CD3-stimulated CD4+ T cells, irrespective of the presence of IL-12, whereas IFN-alpha suppressed the expression of IL-5 and IL-13. Of note, IFN-alpha enhanced the expression of mRNA for c-Maf, T-bet, and Fox-P3, irrespective of the presence of IL-12, but not that for GATA-3, in anti-CD3-stimulated CD4+ T cells. CONCLUSION: These results indicate that IFN-alpha enhances the induction of TH1 responses through upregulation of T-bet mRNA expression, as well as the induction of TH2 responses through upregulation of c-Maf mRNA expression, followed by IL-4 expression. Moreover, the data also suggest that IFN-alpha might suppress the expression of IL-5 and IL-13 in differentiated TH2 cells.

CD4 Antigens↗
PubMed2005

Vertebral fracture and bone mineral density in women receiving high dose glucocorticoids for treatment of autoimmune diseases.

OBJECTIVE: To evaluate the factors influencing the occurrence of vertebral fracture in patients receiving high dose glucocorticoids (GC). METHODS: A cross-sectional study was performed on women who had received at least 0.5 mg/kg of oral glucocorticoid for the treatment of autoimmune diseases for more than 1 month between 1998 and 2003. Logistic regression analysis and chi-square test were used to examine the effects of glucocorticoid dose and other factors on vertebral fractures. Receiver-operating characteristics curve (ROC) analysis was used to determine the bone mineral density (BMD) cutoff value for the risk of vertebral fracture. RESULTS: The study population comprised 160 women, including 35 with vertebral fractures. In ROC analysis, the BMD threshold of the risk of fracture for postmenopausal women (0.787 g/cm2 , T score -2.1) was lower than that for premenopausal women (0.843 g/cm2 , T score -1.7). Among patients with fractures, 7 of 16 premenopausal patients had normal BMD values (T score > -1), whereas only one of 19 postmenopausal patients showed a comparable level of BMD. Additionally, vertebral fracture was more frequent for patients with high total cholesterol values (> 280 mg/dl) than for those with normal total cholesterol values (< 220 mg/dl). Moreover, patients with high total cholesterol values had lower BMD values than those with normal total cholesterol values. CONCLUSION: The fact that vertebral fracture frequently occurred in premenopausal patients with normal BMD and evidence that hyperlipidemia correlated with fracture suggest the pathology of vertebral fracture secondary to high dose glucocorticoid therapy is multifactorial and possibly involves lipid metabolism.

Adolescent↗
PubMed2004

Enhanced generation of endothelial cells from CD34+ cells of the bone marrow in rheumatoid arthritis: possible role in synovial neovascularization.

OBJECTIVE: To examine the capacity of bone marrow CD34+ cells to generate endothelial cells, in order to assess the role of bone marrow in neovascularization in the synovium of rheumatoid arthritis (RA). METHODS: CD34+ cells purified from the bone marrow of 13 patients with active RA and 9 control subjects (7 osteoarthritis [OA] patients and 2 healthy individuals) were cultured in the presence of stem cell factor (10 ng/ml) and granulocyte-macrophage colony-stimulating factor (1 ng/ml). After 18 days of incubation, the generation of endothelial cells was assessed by flow cytometry. The generation of endothelial cells was compared with the degree of vascularization in the synovial tissues and with the microvessel densities in the synovium, as determined by microscopy. The expression of vascular endothelial growth factor receptor 2/kinase insert domain receptor (KDR) messenger RNA (mRNA) in CD34+ cells was examined by quantitative reverse transcription-polymerase chain reaction. RESULTS: The generation of CD14+ cells from bone marrow-derived CD34+ cells from RA patients was comparable to that from control subjects. However, the generation of von Willebrand factor (vWF)-positive cells and CD31+/vWF+ cells from RA bone marrow-derived CD34+ cells was significantly higher than that from control subjects (P = 0.004 and P = 0.030, respectively). The generation of vWF+ cells from bone marrow CD34+ cells correlated significantly with the microvessel densities in the synovial tissues (r = 0.569, P = 0.021). Finally, RA bone marrow CD34+ cells expressed KDR mRNA at higher levels than OA bone marrow CD34+ cells. CONCLUSION: These results indicate that RA bone marrow CD34+ cells have enhanced capacities to differentiate into endothelial cells in relation to synovial vascularization. The data therefore suggest that bone marrow CD34+ cells might contribute to synovial neovascularization by supplying endothelial precursor cells and, thus, play an important role in the pathogenesis of RA.

Aged↗
PubMed2004

Inhibitory effects of bucillamine on the expression of vascular cell adhesion molecule-1 in human umbilical vein endothelial cells.

Bucillamine (BUC) has been found to have beneficial effects in the treatment of rheumatoid arthritis (RA), in which the activation of endothelial cells plays an important role in the pathogenesis. The current studies examined the effect of BUC and its intramolecular disulfide form (BUC-ID) on the expression of adhesion molecules in human umbilical vein endothelial cells (HUVEC) stimulated with tumor necrosis factor-alpha (TNF-alpha). HUVEC (4 x 10(4)/well) were incubated with medium M199 containing heparin and 20% FCS with endothelial cell growth supplement (ECGS) for 24 h in the presence or absence of BUC or BUC-ID, after which the culture medium was replaced with ECGS free medium. Then the cultures were further carried out for additional 24 h with TNF-alpha (10 ng/ml) in the presence or absence of BUC or BUC-ID. BUC-ID, but not BUC, appeared to suppress the expression of VCAM-1 on HUVEC stimulated with TNF-alpha in a dose-response manner at its pharmacologically relevant concentrations (0.3-3.0 microg/ml), whereas only the 3 microg/ml concentration level of BUC-ID had a statistically significant effect, although the effect was relatively small. By contrast, lower concentrations of BUC-ID (1-3 microg/ml) suppressed the secretion of soluble VCAM-1 by HUVEC much more effectively. Of note, at the concentration of 3 microg/ml neither BUC nor BUC-ID significantly influenced the expression of ICAM-1 and E-selectin on TNF-alpha stimulated HUVEC. These results indicate that BUC-ID, but not BUC, specifically downregulates the surface expression of VCAM-1 as well as the release of soluble VCAM-1 by HUVEC stimulated with TNF-alpha. BUC-ID suppressed the production of solubleVCAM-1 by RA bone marrow CD34+ cells stimulated with SCF, GM-CSF and TNF-alpha more effectively than BUC. The data thus suggest that one of the mechanisms of action of BUC involves the inhibition of the activation of endothelial cells.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2004

[Central nervous system involvement in connective tissue diseases].

Neuropsychiatric manifestations are relatively common and serious complications in systemic lupus erythematosus (CNS lupus). Overall, in patients with CNS lupus, CSF IgM, IgA, IgG indexes (indicators of intrathecal Ig synthesis) as well as CSF IL-6 activities were significantly elevated. Of note, especially in patients lupus psychosis, but not in those with focal CNS lesions, anti-ribosomal P antibody (anti-P) in the sera as well as anti-neuronal antibody (anti-N) in the CSF was significantly elevated in relation to their CNS disease activities. These data indicate that the immune system activation within the CNS, possibly resulting in the elevation of CSF anti-N, plays an important role in the pathogenesis of CNS lupus, including lupus psychosis. CNS involvement in Behçet's disease, usually called neuro-Behçet's syndrome (NB), includes acute type and chronic progressive type. Acute NB is characterized by acute meningoencephalitis with focal lesions, presenting high intensity areas in T2-weightened images or Flare images on MRI scans, whereas chronic progressive NB is characterized by intractable slowly progressive dementia, ataxia and dysarthria with persistent elevation of CSF IL-6 activity. Chronic progressive NB is resistant to conventional treatment with steroid, cyclophosphamide, or azathioprine, but responds to low dose methotrexate. As for ANCA-related vasculitis, pachymeningitis has been found to be associated with P-ANCA as well as C-ANCA.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed2004

High diagnostic value of anticalpastatin autoantibodies in rheumatoid arthritis detected by ELISA using human erythrocyte calpastatin as antigen.

OBJECTIVE: To develop a quantitative method of measuring autoantibodies against human calpastatin in rheumatoid arthritis (RA) and to determine their diagnostic value compared with other autoimmune and articular diseases. METHODS: We performed a highly sensitive ELISA for IgG and IgM anticalpastatin autoantibodies in human sera using human erythrocyte calpastatin as an antigen. Samples were diluted 1:2000 for the measurement of IgG and 1:400 for IgM. RESULTS: IgG anticalpastatin antibodies were found in the sera of 48 of 58 patients (82.8%) with RA. In contrast, IgG anticalpastatin antibodies were found in the sera of only 2 of 11 (8.3%) patients with osteoarthritis (OA). Compared to sera from patients with other autoimmune diseases, anticalpastatin antibody sensitivity for RA was better than that of systemic lupus erythematosus (5.6%), systemic sclerosis (0%), mixed connective tissue disease (0%), and Sjögren's syndrome (20%). IgG anticalpastatin antibodies also showed high specificity (96.1%) for RA. Almost 90% of patients with RA were positive for IgG or IgM anticalpastatin antibodies. CONCLUSION: We have developed a simple, sensitive, specific, and quantitative ELISA for anticalpastatin antibodies that may have a high diagnostic value for RA.

Adult↗
PubMed2003

Behçet's disease.

Behçet's disease is characterized by recurrent aphthous stomatitis, uveitis, genital ulcers, and skin lesions. The role of the HLA-B*51 gene has been confirmed in recent years, although its contribution to the overall genetic susceptibility to Behçet's disease was estimated to be only 19%. The production of a variety of cytokines by T cells activated with multiple antigens has been shown to play a pivotal role in the activation of neutrophils. As regards the treatment, anti-tumor necrosis factor alpha therapy has been shown to be effective for mucocutaneous symptoms as well as for sight-threatening panuveitis, although a randomized, controlled trial is required.

Animals↗