Biomedical subjects

H Ihn

Publications and source records attributed to H Ihn.

At least 73 records · Page 4Linked to original sources

PubMed1998

Increased expression of TGF-beta receptors by scleroderma fibroblasts: evidence for contribution of autocrine TGF-beta signaling to scleroderma phenotype.

Scleroderma fibroblasts exhibit numerous phenotypic differences when compared with healthy skin fibroblasts. Some of these differences, in particular overexpression of collagen type I and other extracellular matrix proteins, parallel the effect of transforming growth factor-beta (TGF-beta) on dermal fibroblasts, suggesting that the scleroderma fibroblast phenotype may result from activation of autocrine TGF-beta signaling. To test this hypothesis we examined the role of TGF-beta Type I and Type II receptors in regulating collagen type I transcription. We have shown that overexpression of either Type I or Type II receptors significantly (3-4-fold) increases alpha2 (I) collagen promoter activity in transient transfection assays in dermal fibroblasts. Addition of anti-TGF-beta antibody abolished, whereas addition of plasmin enhanced, the stimulatory effect of receptor overexpression on collagen promoter activity, suggesting that this effect depends on autocrine TGF-beta. Moreover, these cotransfection experiments indicated that expression levels of TGF-beta receptors is a limiting factor in the autocrine regulation of collagen type I transcription by TGF-beta. Comparison of the TGF-beta receptor Type I and Type II mRA expression levels in scleroderma and normal fibroblasts have indicated elevated expression (2-fold) of both receptor types in scleroderma cells, which correlated with increased binding of TGF-beta. Significantly, elevated TGF-beta receptor levels correlated with elevated alpha2 (I) collagen mRNA levels. These results suggest that the elevated production of collagen type I by scleroderma fibroblasts results from overexpression of TGF-beta receptors.

Collagen↗

PubMed1998

Increased serum levels of soluble vascular cell adhesion molecule-1 and E-selectin in patients with systemic sclerosis.

OBJECTIVE: To determine the serum levels of soluble vascular cell adhesion molecule-1 (sVCAM-1) and soluble E-selectin (sE-selectin) in patients with systemic sclerosis (SSc). METHOD: Serum samples from 80 patients with SSc and 20 healthy control subjects were examined by a sensitive enzyme-linked immunosorbent assay. RESULTS: The serum levels of sVCAM-1 and sE-selectin were significantly higher in the patients with SSc than in the healthy controls. The serum levels of sVCAM-1 were correlated with the presence of pulmonary fibrosis, joint involvement and elevated erythrocyte sedimentation rate levels. The serum levels of sE-selectin were correlated with the presence of pulmonary fibrosis. CONCLUSION: These results suggest that endothelial activation is involved in the development of this disease.

Adult↗

PubMed1998

Increased production of interleukin 6 and interleukin 8 in scleroderma fibroblasts.

OBJECTIVE: To determine additional abnormal characteristics related to cytokines in fibroblasts derived from systemic sclerosis (SSc), we examined the production of interleukin 6 (IL-6) and IL-8 and their mRNA levels both in scleroderma fibroblasts and in those from normal skin. METHODS: Cultured fibroblasts from patients with SSc and healthy controls were examined. Production of IL-6 and IL-8 was assessed by specific ELISA, and the levels of IL-6 and IL-8 mRNA were determined by reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: Basal production of both IL-6 and IL-8 was significantly increased in scleroderma fibroblasts compared with controls. When cells were stimulated with either IL-1beta (50 pg/ml) or tumor necrosis factor-alpha (TNF-alpha: 10 ng/ml), the production of IL-6 and IL-8 was predominantly increased in both cell strains and there was no significant difference in the production of IL-6 and IL-8 between them. When normal fibroblasts were stimulated with IL-1beta for 48 h and subcultured, both IL-6 and IL-8 production were significantly increased, and production remained elevated even after 3 passages. RT-PCR revealed that IL-6 and IL-8 mRNA were detected in scleroderma fibroblasts but not in normal skin fibroblasts without cytokine stimulation. When stimulated with IL-1beta, both cell strains expressed IL-6 and IL-8 mRNA to almost the same extent. CONCLUSION: Increased production of IL-6 and IL-8 by scleroderma fibroblasts suggests that these cells may have been stimulated by certain cytokines in vivo.

Cells, Cultured↗

PubMed1998

Serum levels of interleukin 6 (IL-6), oncostatin M, soluble IL-6 receptor, and soluble gp130 in patients with systemic sclerosis.

OBJECTIVE: To determine whether serum interleukin 6 (IL-6), oncostatin M (OSM), soluble IL-6 receptor (sIL-6R), and soluble gp130 (sgp130) levels in patients with systemic sclerosis (SSc) are elevated and whether they are correlated with the clinical or serological features of the disease. METHODS: Serum samples from patients with SSc (n = 55) and control subjects (n = 20) were investigated by ELISA. Patients were divided into 4 groups: 12 with limited cutaneous SSc (lSSc) < or = 3 years' duration (early lSSc), 22 with lSSc > 3 years' duration (late lSSc), 9 with diffuse cutaneous SSc (dSSc) < or = 3 years' duration (early dSSc), and 12 with dSSc > 3 years' duration (late dSSc). RESULTS: Serum IL-6 levels were significantly elevated in patients with early dSSc compared with controls. In addition, serum IL-6 was detected more frequently in patients with pulmonary fibrosis, and these values were inversely correlated with the percentage of vital capacity of individual patients. Furthermore, serum IL-6 levels were correlated with erythrocyte sedimentation rates, C-reactive protein, and IgG and IgA levels in patients. Serum sIL-6R levels were significantly higher in patients with lSSc versus controls. Serum OSM and sgp130 levels were not significantly elevated in patients with SSc compared with controls. CONCLUSION: We suggest that IL-6 and sIL-6R may contribute to the disease process in SSc. In particular, IL-6 may be related to the early phase of the disease and the development of pulmonary fibrosis in SSc.

Adolescent↗

PubMed1998

High seroprevalence of Helicobacter pylori infection in patients with systemic sclerosis: association with esophageal involvement.

OBJECTIVE: To determine the prevalence and clinical relevance of Helicobacter pylori infection in patients with systemic sclerosis (SSc). METHODS: Serum samples were obtained from 124 patients with SSc (67 with limited cutaneous SSc, 57 with diffuse cutaneous SSc). Fifty samples from age and sex matched individuals were used as controls. IgG antibodies to H. pylori infection were measured by ELISA. RESULTS: IgG antibodies to H. pylori were found in 55.6% (69 of 124) of the patients with SSc, significantly more than in the controls. There was a significant correlation of the presence of antibodies to H. pylori with the prevalence of esophageal hypomotility in the patients with SSc (p < 0.02). CONCLUSION: Patients with SSc have H. pylori infection at a higher prevalence than the general population. H. pylori might play a role in the development of esophageal dysfunction in SSc.

Adult↗

PubMed1998

Autoantibodies against calpastatin in sera from patients with systemic sclerosis.

OBJECTIVE: To determine the prevalence and clinical correlation of anti-calpastatin antibodies in patients with systemic sclerosis (SSc). METHODS: Serum samples from patients with limited cutaneous SSc (lSSc; n=36), diffuse cutaneous SSc (dSSc; n=27), and healthy control subjects (n=29) were examined by an ELISA using human recombinant calpastatin as antigens. RESULTS: IgG anti-calpastatin antibodies were positive in 15 (24%) of 63 patients with SSc, which was similar to the frequency of IgM anti-calpastatin antibody positivity (14/63, 22%). The presence of anticentromere antibodies was associated with the presence of IgG and/or IgM anti-calpastatin antibodies. The patients with SSc positive for IgG anti-calpastatin antibodies had significantly higher erythrocyte sedimentation rates (ESR) compared with those negative for IgG anti-calpastatin antibodies. Furthermore, the levels of IgG anti-calpastatin antibodies correlated positively with the levels of ESR. The patients with dSSc positive for IgM anti-calpastatin antibodies had significantly higher frequency of inflammatory joint and muscle involvement compared with those negative for IgM anti-calpastatin antibodies. Four (80%) of 5 patients with dSSc with both joint and muscle involvement produced IgM anti-calpastatin antibodies. CONCLUSION: The presence of anti-calpastatin antibodies may be a clue to mechanisms of the inflammatory change occurring in SSc. Furthermore, the presence of anti-calpastatin antibodies could be a novel and useful serologic tool for recognizing patients with dSSc with inflammatory joint and muscle involvement.

Adolescent↗

PubMed1997

Oncostatin M stimulates transcription of the human alpha2(I) collagen gene via the Sp1/Sp3-binding site.

Oncostatin M (OSM), a member of the hematopoietic cytokine family, has been implicated in excessive bone growth and in the process of fibrosis. As part of an ongoing study of the molecular mechanisms of fibrosis, we have investigated the transcriptional regulation of the alpha2(I) collagen gene by OSM in human fibroblasts. An OSM response element was mapped by deletional analysis between base pairs (bp) -148 and -108 in the alpha2(I) collagen promoter. Further functional analysis of the alpha2(I) collagen promoter containing various substitution mutations revealed that both the basal activity and OSM stimulation of this promoter are mediated by a TCCTCC motif located between bp -128 and -123. Furthermore, three copies of the 12-bp synthetic alpha2(I) collagen promoter fragment containing the "TCC" motif conferred OSM inducibility to the otherwise unresponsive thymidine kinase promoter. Electrophoretic mobility shift assays demonstrated that the TCCTCC motif constitutes a novel binding site for the transcription factors Sp1 and Sp3. No differences have been observed in in vitro gel shift binding assays between unstimulated and OSM-stimulated fibroblasts. However, subtle conformational changes were detected in the region of the promoter surrounding TCC repeats after OSM stimulation using in vivo footprint analysis. In conclusion, this study characterized a dual-function response element that mediates the basal activity and OSM stimulation of the human alpha2(I) collagen promoter.

Binding Sites↗

PubMed1997

Sp3 is a transcriptional activator of the human alpha2(I) collagen gene.

Sp3 is an ubiquitously expressed transcription factor, closely related to Sp1 but, unlike Sp1, it often functions as a transcriptional repressor. In this study we investigated the role of Sp3 in regulating the transcription of the human alpha2(I) collagen gene. We show that Sp1 and Sp3 specifically bind to three of the previously characterized cis -elements in this promoter, including two positive cis-elements between -303 and -271 and -128 and -123, and a repressor site between -164 and -159, but do not bind to the fourth cis-element bound by CBF. Functional analyses of Sp3 and Sp1 in Drosophila cells indicate that each protein transactivates the human alpha2(I) collagen promoter with equal potency and, when tested together, have an additive effect on the promoter activity. Furthermore, in vitro transcription assays demonstrate that both Sp1 and Sp3 are capable of supporting transcription from the collagen promoter independently of each other. However, when activities of both Sp1 and Sp3 are blocked with specific antibodies, in vitro transcription from this promoter is almost completely abolished. The results of this study demonstrate that Sp3 is as potent an activator of the human alpha2(I) collagen promoter as is Sp1 and that a transcriptional activity of the human alpha2(I) promoter is dependent on both proteins.

Collagen↗

PubMed1997

Circulating intercellular adhesion molecule-1 in the sera of patients with systemic sclerosis: enhancement by inflammatory cytokines.

We measured serum levels of circulating intercellular adhesion molecule-1 (cICAM-1) in patients with systemic sclerosis (SSc) and normal controls. The levels of cICAM-1 were determined by sandwich enzyme-linked immunosorbent assay in sera from 88 patients with SSc and in 20 healthy controls. In addition, these levels were examined in the supernatants of cultured peripheral blood mononuclear cells (PBMC) and dermal fibroblasts from 10 patients with SSc and 10 healthy control subjects. Serum levels of cICAM-1 were significantly higher in patients with SSc than in healthy controls. Serum cICAM-1 levels were significantly higher in patients with diffuse cutaneous SSc (dcSSc) than in patients with limited cutaneous SSc (lcSSc). These serum levels were correlated with the presence of contracture of phalanges, pulmonary fibrosis, joint involvement and increased erythrocyte sedimentation rate. The release of cICAM-1 was significantly increased in the supernatants of cultured PBMC from patients with SSc. Moreover, inflammatory cytokines (interferon-gamma, interleukin-1 and tumor necrosis factor-alpha) enhanced the release of cICAM-1 in vitro in SSc cells. These findings suggest that cICAM-1 may be involved in immune reactions in this disease.

Cells, Cultured↗

PubMed1997

Prevalence and clinical relevance of 52-kDa and 60-kDa Ro/SS-A autoantibodies in Japanese patients with systemic sclerosis.

OBJECTIVE: To determine the prevalence of 52-Kda and 60-Kda Ro/SS-A autoantibodies in serum samples from Japanese patients with systemic sclerosis (SSc). METHODS: Serum samples from 263 Japanese patients with SSc were examined by double immunodiffusion and enzyme linked immunosorbent assay (ELISA). RESULTS: By double immunodiffusion, 29 serum samples from patients with SSc were found to possess anti-Ro/SS-A antibodies. By ELISA, 31 serum samples were positive for anti-Ro52 and/or anti-Ro60. Of 27 serum samples that were positive by both methods, 15 reacted with both Ro52 and Ro60, five with Ro52 alone, and seven with Ro60 alone. Eleven of 12 patients with both anti-Ro52 and anti-Ro60 and all five patients with anti-Ro52 alone had Sjögren's syndrome, while only one of six patients with anti-Ro60 alone had this disorder. CONCLUSIONS: Anti-Ro52 may be a serological marker for the presence of Sjögren's syndrome in anti-Ro/SS-A-positive patients with SSc.

Antibodies, Antinuclear↗

PubMed1997

Distribution of anti-p80-coilin autoantibody in collagen diseases and various skin diseases.

Anti-p80-coilin antibody produces a unique pattern of immunofluorescence staining called nuclear dots characterized by the presence of up to six discrete nuclear bodies in interphase cell nuclei. The distribution of this antibody and its clinical relevance have not been established. We studied the prevalence of anti-p80-coilin antibody in the sera from 810 patients with collagen diseases and various skin diseases. Five sera showed the nuclear dot pattern by indirect immunofluorescence on an HEp-2 cell substrate, and reacted by immunoblotting with 80-kDa protein in a nuclear extract from HeLa cells. Four of these sera were from patients with localized scleroderma, and the other was from a patient with primary Raynaud's phenomenon. The patients with localized scleroderma who were positive for anti-p80-coilin antibody had all been classified as having linear scleroderma. They had only one or two lesions, and were negative for antihistone and anti-single-stranded DNA antibodies. Our data indicate that anti-p80-coilin antibody is uncommon in skin diseases: however, this antibody is present in patients with a milder form of linear scleroderma, although the incidence of positivity may not be high.

Autoantibodies↗

PubMed1996

Transcriptional regulation of the human alpha2(I) collagen gene. Combined action of upstream stimulatory and inhibitory cis-acting elements.

This study identifies three regions of the human alpha2(I) collagen promoter involved in the binding of nuclear factors. These regions include sequences from -173 to -155 (footprint I), -133 to -119 (footprint II), and -101 to -72 (footprint III). A novel positive cis-element containing a TCCTCC motif was identified within footprint II. In addition, we demonstrated that a pyrimidine-rich region within footprint I is a binding site for a transcriptional repressor, and a CCAAT motif within footprint III is a binding site for a transcriptional activator. Comparative functional analysis of the cis-acting elements within the proximal 350 base pairs of this promoter, including previously characterized Sp1 binding sites at -300, indicates that constitutive activity of this promoter is regulated equivalently by the three positive cis-acting elements at -300, -125, and -80. Mutations in the repressor site at -160 increase constitutive activity by 4-6-fold. However, simultaneous mutations of the repressor site and the cis-regulatory element at either the -300 or -125 sites result in no increase in constitutive transcription activity suggesting interaction between the activators and repressor elements. In contrast, simultaneous mutation of the CCAAT motif and the repressor site results in about a 4-fold increase, suggesting that activation via the CCAAT motif may be independent of this repressor.

Animals↗

PubMed1996

Elevated soluble CD23 levels in the sera from patients with localized scleroderma.

Soluble CD23 (sCD23) is closely related to B-cell activation and elevated serum levels of sCD23 have been reported in several autoimmune disorders. This study investigated the serum levels of sCD23 and determined the correlation of sCD23 with other immunologic abnormalities and clinical features in localized scleroderma. We examined 49 serum samples by an enzyme-linked immunosorbent assay in the following three subgroups: 15 patients with generalized morphoea, 22 with linear scleroderma, and 12 with morphoea. The serum levels of sCD23 were significantly elevated in patients with localized scleroderma, compared with those in healthy individuals. Of the three subgroups of localized scleroderma, patients with generalized morphoea had the highest levels of serum sCD23. The frequency of IgM antihistone antibody (AHA) and IgM rheumatoid factor (RF), the number of linear lesions, and the frequency of muscle involvement were significantly higher in patients with elevated sCD23 levels than in those with normal levels of sCD23. A significant correlation between the serum sCD23 level and the number of involved areas of the body was observed. Our data suggest that the activation of virgin B cells, which is reflected by elevated sCD23 levels, is closely associated with the production of IgM autoantibodies in localized scleroderma and furthermore that the serum levels of sCD23 are a new serological indicator of the severity of localized scleroderma.

Adolescent↗

PubMed1996

Soluble CD4 and CD8 in serum from patients with localized scleroderma.

Localized scleroderma has been shown to be accompanied by various immunologic abnormalities. To obtain functional information on activated CD4+ or CD8+ T cells, we studied the levels of soluble CD4 (sCD4) and soluble CD8 (sCD8) in serum from patients with localized scleroderma. Serum samples were examined by enzyme-linked immunosorbent assay. The samples were obtained from 49 patients in the following three subgroups: 15 patients with generalized morphea, 22 with linear scleroderma, and 12 with morphea. The levels of sCD4 and sCD8 were significantly elevated in patients with generalized morphea. Furthermore, these patients showed significantly higher levels of sCD4 than those with systemic sclerosis (SSc). The frequency of positivity for IgG anti-single-stranded DNA (ssDNA) antibody was significantly higher in localized scleroderma patients with elevated sCD4 levels than in patients with normal sCD4 levels. The frequency of positivity for antinuclear antibodies, IgM antihistone antibodies, IgG anti-ssDNA antibody and rheumatoid factor, and elevated sCD23 levels were significantly higher in localized scleroderma patients with elevated sCD8 levels than in patients with normal sCD8 levels. Our findings suggest that both CD4+ and CD8+ T cells are activated in vivo in generalized morphea and that the immunologic events in generalized morphea are different from those in SSc.

Adult↗

PubMed1996

Autoantibodies to mitochondrial 2-oxo-acid dehydrogenase complexes in localized scleroderma.

Sera from patients with localized scleroderma frequently produce cytoplasmic staining by indirect immunofluorescence, although the antigen remains to be determined. We studied the prevalence, antigen specificity and associated clinical characteristics of anti-cytoplasmic antibodies in localized scleroderma. Serum samples from 60 patients with localized scleroderma were examined by indirect immunofluorescence analysis and immunoblotting. By immunofluorescence analysis on HEp-2 cell substrate, seven of 60 (12%) patients were shown to be positive for anti-cytoplasmic antibodies. Among these, six patients with generalized morphea had anti-mitochondrial antibodies as shown by immunoblotting: they showed reactivity with the E2 component of pyruvate dehydrogenase complex (PDC), with protein X, and with the E2 component of alpha-oxo-glutarate dehydrogenase complex, while two of them showed reactivity with PDC-E1 alpha. One of these patients who was positive for anti-PDC-E1 alpha antibody showed laboratory abnormalities, suggesting the presence of primary biliary cirrhosis. The age of disease onset was significantly higher in these six patients than in those without anti-mitochondrial antibodies. Furthermore, five of them were classified into generalized morphea with multiple plaque lesions but without linear lesions (multiple plaque type). These observations suggest that major antigens for anti-cytoplasmic antibodies in patients with localized scleroderma are mitochondrial enzymes, 2-oxo-acid dehydrogenase complexes. Patients with anti-mitochondrial antibodies may comprise a unique subset of localized scleroderma designated multiple plaque type of generalized morphea of older onset.

Adolescent↗

PubMed1996

Measurement of anticardiolipin antibodies by ELISA using beta 2-glycoprotein I (beta 2-GPI) in systemic sclerosis.

In order to determine the prevalence and clinical significance of beta 2-GPI-dependent anticardiolipin antibodies (beta 2-GPI/aCL) in patients with systemic sclerosis (SSc), serum samples from 80 patients with SSc, 20 patients with systemic lupus erythematosus (SLE), and 120 healthy control subjects were examined by ELISA using purified beta 2-GPI. IgG isotype beta 2-GPI/aCL was present in eight of 80 patients with SSc (10%), and the presence of beta 2-GPI/aCL IgG was significantly correlated with the presence of isolated pulmonary hypertension (PH). Furthermore, levels of beta 2-GPI/aCL IgG were significantly correlated with levels of mean pulmonary arterial pressure. These data suggest that IgG isotype beta 2-GPI/aCL might be a serological indicator of the severity of PH in patients with SSc.

Antibodies, Anticardiolipin↗

PubMed1996

Connective tissue growth factor gene expression in tissue sections from localized scleroderma, keloid, and other fibrotic skin disorders.

Connective tissue growth factor (CTGF) is a novel peptide that exhibits platelet-derived growth factor-like activities and is produced by skin fibroblasts after activation with transforming growth factor-beta. Coordinate expression of transforming growth factor-beta followed by CTGF during wound repair suggests a cascade process for control of tissue regeneration. We recently reported a significant correlation between CTGF mRNA expression and histologic sclerosis in systemic sclerosis. To confirm the relation between CTGF and skin fibrosis, we investigated CTGF gene expression in tissue expression in tissue sections from patients with localized scleroderma, keloid, other sclerotic skin disorders using nonradioactive in situ hybridization. In localized scleroderma, the fibroblasts with positive signals for CTGF mRNA were scattered throughout the sclerotic lesions with no preferential distribution around the inflammatory cells or perivascular regions, whereas the adjacent nonaffected dermis was negative for CTGF mRNA. In keloid tissue, the fibroblasts positive for CTGF mRNA were diffusely distributed, especially in the peripheral expanding lesions. In scar tissue, however, the fibroblasts in the fibrotic lesions showed partially positive signals for CTGF mRNA. In eosinophilic fasciitis, nodular fasciitis, and Dupuytren's contracture, CTGF mRNA was also expressed partially in the fibroblasts of the fibrotic lesions. Our findings reinforce a correlation between CTGF gene expression and skin sclerosis and support the hypothesis that transforming growth factor-beta plays an important role in the pathogenesis of fibrosis, as it is the only inducer for CTGF identified to date.

Adolescent↗

PubMed1996

Antiubiquitin antibody in localised and systemic scleroderma.

OBJECTIVE: To determine the presence of antiubiquitin antibody (AUbA) in localised scleroderma and systemic sclerosis, as it is frequently found in the sera of patients with systemic lupus erythematosus (SLE) and has also been shown to have a close relationship with antihistone antibodies that have an important role in scleroderma. METHODS: Serum samples from patients with localised scleroderma (n = 48) and systemic sclerosis (n = 52) were examined by enzyme linked immunosorbent assay. Twenty samples from patients with SLE, 20 from patients with dermatomyositis, and 30 samples from healthy individuals were used as controls. RESULTS: AUbA was demonstrated in 44% of patients with localised scleroderma and in 42% of those with systemic sclerosis. The presence of AUbA correlated with the presence of antihistone antibodies in both localised scleroderma and systemic sclerosis. CONCLUSIONS: AUbA is frequently present in patients with localised scleroderma and systemic sclerosis. Induction of AUbA is closely associated with that of antihistone antibodies, suggesting that ubiquitinated histone may be the target in autoimmune responses of these disorders.

Adolescent↗