Biomedical subjects

S A Jimenez

Publications and source records attributed to S A Jimenez.

At least 19 recordsLinked to original sources

PubMed2006

NF-kappaB as a potential therapeutic target in osteoarthritis and rheumatoid arthritis.

The family of nuclear factor-kappaB (NF-kappaB) transcription factors is intimately involved in the regulation of expression of numerous genes in the setting of the inflammatory response. Since inflammatory processes play a fundamental role in the damage of articular tissues, many in vitro and in vivo studies have examined the contribution of components of the NF-kappaB signaling pathways to the pathogenesis of various rheumatic diseases, in particular, of osteoarthritis (OA) and rheumatoid arthritis (RA). Inflammation, cartilage degradation, cell proliferation, angiogenesis and pannus formation are processes in which the role of NF-kappaB is prominent. Consequently, large efforts have been devoted to the study of the pharmacologic modulation of the NF-kappaB pathways. These studies have employed currently available therapeutic agents including non-steroidal anti-inflammatory drugs, corticosteroids, nutraceuticals and disease-modifying anti-rheumatic drugs, as well as novel small molecule inhibitors targeted to specific proteins of the NF-kappaB pathways. In addition, promising strategies such as improved antisense DNA therapy and RNA interference have been examined with encouraging results. However, since NF-kappaB also plays a crucial beneficial role in normal physiology and technical problems for effective gene therapy still remain, further research will be needed before NF-kappaB-aimed strategies become an effective therapy for joint diseases, such as OA and RA.

Animals↗

PubMed2005

Osteoarthritis cartilage histopathology: grading and staging.

OBJECTIVE: Current osteoarthritis (OA) histopathology assessment methods have difficulties in their utility for early disease, as well as their reproducibility and validity. Our objective was to devise a more useful method to assess OA histopathology that would have wide application for clinical and experimental OA assessment and would become recognized as the standard method. DESIGN: An OARSI Working Group deliberated on principles, standards and features for an OA cartilage pathology assessment system. Using current knowledge of the pathophysiology of OA morphologic features, a proposed system was presented at OARSI 2000. Subsequently, this was widely circulated for comments amongst experts in OA pathology. RESULTS: An OA cartilage pathology assessment system based on six grades, which reflect depth of the lesion and four stages reflecting extent of OA over the joint surface was developed. CONCLUSIONS: The OARSI cartilage OA histopathology grading system appears consistent and simple to apply. Further studies are required to confirm the system's utility.

Animals↗

PubMed2005

Inhibition of collagen gene expression in systemic sclerosis dermal fibroblasts by mithramycin.

BACKGROUND: The anti-tumour antibiotic mithramycin is also a potent inhibitor of fibrosis after glaucoma surgery. This drug displays high affinity binding to GC-rich sequences in DNA, including those present in the promoter of the gene encoding the alpha1 chain of type I collagen (COL1A1). OBJECTIVE: To evaluate the effects of mithramycin on COL1A1 expression in systemic sclerosis fibroblasts. METHODS: Confluent cultures of dermal fibroblasts from patients with recent onset diffuse systemic sclerosis were treated with mithramycin in vitro. Cell viability and protein expression were examined by fluorescence and confocal imaging. Type I collagen production was analysed by confocal imaging and metabolic labelling. COL1A1 messenger RNA levels and stability were assessed by northern hybridisation, and COL1A1 transcription was examined by transient transfections. RESULTS: Treatment of systemic sclerosis fibroblasts with mithramycin (10-100 nmol/l) did not cause significant cytotoxicity. Type I collagen biosynthesis decreased by 33-40% and 50-70% in cells cultured with mithramycin at 10 nmol/l and 100 nmol/l, respectively. Mithramycin at 50 nmol/l decreased COL1A1 mRNA levels by 40-60%. The effects of mithramycin on collagen gene expression were mediated by transcriptional and post-transcriptional mechanisms as shown by the reduction of COL1A1 promoter activity and by a decrease in the stability of these transcripts, respectively. CONCLUSIONS: Mithramycin causes potent inhibition of collagen production and gene expression in systemic sclerosis dermal fibroblasts in vitro in the absence of cytotoxic effects. These results suggest that this drug may be an effective treatment for the fibrotic process which is the hallmark of systemic sclerosis.

Blotting, Northern↗

PubMed2004

Quantification of fetal microchimeric cells in clinically affected and unaffected skin of patients with systemic sclerosis.

OBJECTIVE: Fetal microchimerism has been hypothesized as a potential pathogenic mechanism for systemic sclerosis (SSc). This hypothesis was based on the clinical similarities between SSc and graft-vs-host disease and the identification of microchimeric cells in affected SSc tissues. The aim of this study was to compare the quantity of microchimeric cells in clinically affected and non-affected skin of female patients with SSc. METHODS: Fluorescence in situ hybridization (FISH) and real-time PCR were employed in paired skin biopsies obtained from clinically affected and unaffected areas from five female SSc patients with diffuse cutaneous SSc (dcSSC) and 10 healthy women. All women in the study had delivered a male fetus. RESULTS: FISH analysis revealed the presence of male fetal cells in 1/5 SSc patients (20.0%) compared with 0/10 healthy women (P = 0.0037), whereas quantification by real-time PCR revealed that all SSc samples were positive for male DNA compared with none of the controls. In the five patients with dcSSc, there were similar numbers of microchimeric cells in both affected and unaffected skin (P = 0.4) CONCLUSION: The presence of higher numbers of microchimeric cells in clinically unaffected SSc skin, before any clinically detectable evidence of sclerotic changes, suggests that an influx of microchimeric cells may precede the development of tissue fibrosis. This provides additional support to the hypothesis that fetal microchimerism may play a role in the pathogenesis of SSc.

Aged↗

PubMed2003

Glucosamine sulfate modulates the levels of aggrecan and matrix metalloproteinase-3 synthesized by cultured human osteoarthritis articular chondrocytes.

OBJECTIVE: The functional integrity of articular cartilage is determined by a balance between chondrocyte biosynthesis of extracellular matrix and its degradation. In osteoarthritis (OA), the balance is disturbed by an increase in matrix degradative enzymes and a decrease in biosynthesis of constitutive extracellular matrix molecules, such as collagen type II and aggrecan. In this study, we examined the effects of the sulfate salt of glucosamine (GS) on the mRNA and protein levels of the proteoglycan aggrecan and on the activity of matrix metalloproteinase (MMP)-3 in cultured human OA articular chondrocytes. DESIGN: Freshly isolated chondrocytes were obtained from knee cartilage of patients with OA. Levels of aggrecan and MMP-3 were determined in culture media by employing Western blots after incubation with GS at concentrations ranging from 0.2 to 200 microM. Zymography (casein) was performed to confirm that effects observed at the protein level were reflected at the level of enzymatic activity. Northern hybridizations were used to examine effects of GS on levels of aggrecan and MMP-3 mRNA. Glycosaminoglycan (GAG) assays were performed on the cell layers to determine levels of cell-associated GAG component of proteoglycans. RESULTS: Treatment of OA chondrocytes with GS (1.0-150 microM) resulted in a dose-dependent increase in aggrecan core protein levels, which reached 120% at 150 microM GS. These effects appeared to be due to increased expression of the corresponding gene as indicated by an increase in aggrecan mRNA levels in response to GS. MMP-3 levels decreased (18-65%) as determined by Western blots. Reduction of MMP-3 protein was accompanied by a parallel reduction in enzymatic activity. GS caused a dose-dependent increase (25-140%) in cell-associated GAG content. Chondrocytes obtained from 40% of OA patients failed to respond to GS. CONCLUSIONS: The results indicate that GS can stimulate mRNA and protein levels of aggrecan core protein and, at the same time, inhibit production and enzymatic activity of matrix-degrading MMP-3 in chondrocytes from OA articular cartilage. These results provide a cogent molecular mechanism to support clinical observations suggesting that GS may have a beneficial effect in the prevention of articular cartilage loss in some patients with OA.

Aged↗

PubMed2002

Skeletal abnormalities and ultrastructural changes of cartilage in transgenic mice expressing a collagen II gene (COL2A1) with a Cys for Arg-alpha1-519 substitution.

OBJECTIVE: To examine the mechanism by which the Arg-->Cys 519 mutation causes the clinical phenotype employing transgenic mice that express the mutated human COL2A1. METHODS: A DNA construct under the control of a COL2A1 specific promoter was prepared from genomic DNA isolated from fibroblasts from the proband with primary generalized osteoarthritis (OA) associated with a mild chondrodysplasia. Transgenic mice were obtained by injection of the constructs into pro-nuclei of fertilized eggs from the FVB/N inbred mouse strain. Transgenic mice harboring two alleles of the mutated human COL2A1 were examined for morphological abnormalities and for alterations of their skeletal development. Ultrastructural examination was performed to identify changes in the organization and density of collagen II fibrils in articular cartilage of the transgenic mice. RESULTS: Transgenic mice harboring two alleles of the mutated human collagen gene were smaller than their normal littermates, had a cleft palate, and disorganized growth plate. Electron microscopy of articular cartilage showed a decreased density of collagen II fibrils and revealed chondrocytes with dilated Golgi cysternae. CONCLUSIONS: Expression of a COL2A1 with an Arg-->Cys 519 substitution in transgenic mice causes retardation of skeletal development and ultrastructural alterations in articular cartilage with a profound reduction of the density of the collagen II fibrils in the tissue. These alterations may be responsible for the phenotype of precocious generalized OA and chondrodysplasia displayed by patients harboring this COL2A1 mutation.

Amino Acid Substitution↗

PubMed2002

Influence of prior pregnancies on disease course and cause of death in systemic sclerosis.

BACKGROUND: Microchimerism from fetal or maternal cells transferred during pregnancy has been implicated in the pathogenesis of systemic sclerosis (SSc). OBJECTIVE: To determine whether a prior pregnancy influenced disease progression and cause of death in patients with SSc. PATIENTS AND METHODS: The patients comprised a retrospective study cohort of 111 women with SSc: 78 patients with prior pregnancies (PP) and 33 who were never pregnant (NP), followed up at Thomas Jefferson University. Differences in age at onset, disease subset, organ involvement, cause of death, and type of antinuclear autoantibodies were evaluated statistically, including regression analysis. RESULTS: The age at onset of SSc in NP patients was 32.0 years compared with 45.7 years in patients with one or two prior pregnancies (p<0.0001), 46.6 years in patients with three or four pregnancies (p<0.0001), and 51.3 years in patients with five to seven pregnancies (p<0.0005). In the 16 patients who had an elective pregnancy termination, 14/16 (87.5%) had diffuse SSc v 2/16 (12.5%) with limited SSc (p<0.0001; odds ratio (OR)=49.0). Of the NP women, 7/30 (23%) died from SSc related causes v 3/78 (4%) women who had pregnancies (p=0.0058; OR=7.6). A carbon monoxide transfer factor (TLCO) of <60% and disease duration >10 years was found in 10/13 (77%) NP patients v 10/23 (43%) patients who had pregnancies (p=0.05; OR=4.7), and a TLCO <50% and disease duration >10 years was identified in 7/13 (54%) NP patients v 6/23 (26%) of the patients who had pregnancies (p=0.09; OR=3.2). CONCLUSIONS: There are differences in the age at onset, clinical course, severity of lung involvement, and cause of death in women who develop SSc before pregnancy compared with those who develop it after pregnancies. The NP patients with SSc had onset of disease at an earlier age, more severe lung involvement, and higher rate of death due to SSc.

Adult↗

PubMed2001

Collagen II containing a Cys substitution for Arg-alpha1-519: abnormal interactions of the mutated molecules with collagen IX.

Single amino acid substitutions in collagen II cause heterogeneous cartilage disorders including some chondrodysplasias and certain forms of heritable osteoarthritis. In this study, we examined molecular interactions between normal collagen II and collagen IX, and the effect of a Cys substitution for Arg-alpha1-519 in collagen II on these interactions. Binding assays showed that the association equilibrium constant of collagen IX-collagen II interaction is 15 x 10(6) M(-1). Specificity of the interaction was analyzed by the binding of collagen IX to recombinant collagen II variants lacking fragments of 234 amino acids corresponding to particular D-periods. The results indicated that the C-terminal half of collagen II, which includes the D3 and D4 periods, has a high affinity for collagen IX, and that the nontriple helical telopeptides of collagen II are not essential for the specific binding of collagen IX. Computer analysis of the surface of the mutated collagen II and binding assays showed that a Cys substitution for Arg-alpha1-519 changes electrostatic properties around the mutation site, increases the affinity of mutant collagen II for collagen IX, and possibly alters the specificity of the interaction. Thus, the results indicate that interactions between collagen II and collagen IX are site specific and that single amino acid substitutions in collagen II may change the molecular interactions with collagen IX that could destabilize the cartilaginous matrix.

Amino Acid Substitution↗

PubMed2001

Regulation of type-II collagen gene expression during human chondrocyte de-differentiation and recovery of chondrocyte-specific phenotype in culture involves Sry-type high-mobility-group box (SOX) transcription factors.

During ex vivo growth as monolayer cultures, chondrocytes proliferate and undergo a process of de-differentiation. This process involves a change in morphology and a change from expression of chondrocyte-specific genes to that of genes that are normally expressed in fibroblasts. Transfer of the monolayer chondrocyte culture to three-dimensional culture systems induces the cells to re-acquire a chondrocyte-specific phenotype and produce a cartilaginous-like tissue in vitro. We investigated mechanisms involved in the control of the de-differentiation and re-differentiation process in vitro. De-differentiated chondrocytes re-acquired their chondrocyte-specific phenotype when cultured on poly-(2-hydroxyethyl methacrylate) (polyHEMA) as assayed by morphology, reverse transcriptase PCR of chondrocyte-specific mRNA, Western-blot analysis and chondrocyte-specific promoter activity. Essentially, full recovery of the chondrocyte-specific phenotype was observed when cells that had been cultured for 4 weeks on plastic were transferred to culture on polyHEMA. However, after subsequent passages on plastic, the phenotype recovery was incomplete or did not occur. The activity of a gene reporter construct containing the promoter and enhancer from the human type-II collagen gene (COL2A1) was modulated by the culture conditions, so that its transcriptional activity was repressed in monolayer cultures and rescued to some extent when the cells were switched to polyHEMA cultures. The binding of Sry-type high-mobility-group box (SOX) transcription factors to the enhancer region was modulated by the culture conditions, as were the mRNA levels for SOX9. A transfected human type-II collagen reporter construct was activated in de-differentiated cells by ectopic expression of SOX transcription factors. These results underscore the overt change in phenotype that occurs when chondrocytes are cultured as monolayers on tissue-culture plastic substrata.

Animals↗

PubMed2001

Characterization of a biomaterial with cartilage-like properties expressing type X collagen generated in vitro using neonatal porcine articular and growth plate chondrocytes.

OBJECTIVE: The availability of cartilage with or without the potential to ossify and suitable for surgical restoration and resurfacing of joints is an important clinical problem in arthritis-related pathology, trauma and reconstructive surgery. Here, we designed experiments to generate a biomaterial with cartilage-like properties by culturing neonatal porcine articular and growth plate chondrocytes on a hydrogel substrate and to examine the biochemical and histological characteristics of the resulting tissue. DESIGN: Neonatal porcine epiphyseal and growth plate chondrocytes were cultured on poly(2-hydroxyethyl methacrylate) (polyHEMA)-coated dishes to prevent their adherence to plastic. We previously described that this procedure allows the maintenance of the chondrocyte-specific phenotype for > or = 8 months. Chondrocytes were isolated by successive enzymatic digestions and cultured at high density (>2.0 x 10(7) cells/ml) in DMEM with 10% FBS, 50 microg/ml ascorbic acid, glutamine, vitamins, and antibiotics for up to 10 weeks on 60 mm plastic culture dishes coated with polyHEMA. The tissues produced during culture were studied histologically and biochemically and were examined for cellular proliferation employing(3)H-thymidine incorporation and for their collagen production employing biosynthetic labeling with(14)C-proline and Western blot with specific antibodies. The expression of relevant collagen genes was examined employing RT-PCR. RESULTS: Within 24 h of culture, isolated chondrocytes organized into well-formed clusters and in 2 weeks formed structures with gross appearance and consistency similar to those of natural cartilage. The wet weight of the tissue formed in vitro increased six-fold during the 10-week period of study. Cell proliferation measured by the incorporation of(3)H-thymidine increased during the first 3 weeks and reached a plateau in subsequent weeks. Histological examination showed that the cultures contained rounded chondrocytes embedded in an abundant cartilaginous extracellular matrix. The cartilage formed contained large amounts of collagen and sulfated proteoglycans as examined by staining with Masson's Trichrome and Alcian blue, respectively. Deposition of calcium in the deeper layers of the tissue was demonstrated with the von Kossa stain. Western analyses with specific antibodies showed that type II collagen was present from the first week and progressively increased in the cultures, whereas type X collagen was first detected at 4 weeks and increased with length of culture. When chondrocytes isolated from the growth plate were included, small amounts of type I collagen were detected in the medium of cultured biomaterial as expected. Type III collagen was not detected by Western blot over the 10-week period. High levels of type II and type X collagen gene expression were demonstrated by RT-PCR. CONCLUSION: These studies demonstrate the production in vitro of cartilage-like tissue with similar morphological, histochemical and biochemical characteristics to those of natural growth plate cartilage. The cartilage generated in vitro has the potential to be used in reconstructive surgery and in joint resurfacing and restoration of skeletal defects.

Animals↗

PubMed2001

Role of protein kinase C-delta in the regulation of collagen gene expression in scleroderma fibroblasts.

Working with cultured dermal fibroblasts derived from control individuals and patients with systemic sclerosis (SSc), we have examined the effects of protein kinase C-delta (PKC-delta) on type I collagen biosynthesis and steady-state levels of COL1A1 and COL3A1 mRNAs. Rottlerin, a specific inhibitor of PKC-delta, exerted a powerful, dose-dependent inhibition of type I and type III collagen gene expression in normal and SSc cells. Optimal rottlerin concentrations caused a 70-90% inhibition of type I collagen production, a >80% reduction in COL1A1 mRNA, and a >70% reduction in COL3A1 mRNA in both cell types. In vitro nuclear transcription assays and transient transfections with COL1A1 promoter deletion constructs demonstrated that rottlerin profoundly reduced COL1A1 transcription and that this effect required a 129-bp promoter region encompassing nucleotides -804 to -675. This COL1A1 segment imparted rottlerin sensitivity to a heterologous promoter. Cotransfections of COL1A1 promoter constructs with a dominant-negative PKC-delta expression plasmid showed that suppression of this kinase silenced COL1A1 promoter activity. The results indicate that PKC-delta participates in the upregulation of collagen gene transcription in SSc and suggest that treatment with PKC-delta inhibitors could suppress fibrosis in this disease.

Acetophenones↗

PubMed2000

Detection of cellular microchimerism of male or female origin in systemic sclerosis patients by polymerase chain reaction analysis of HLA-Cw antigens.

OBJECTIVE: Systemic sclerosis (SSc; scleroderma), a disease of unknown origin, displays many similarities to chronic graft-versus-host disease. It occurs most frequently in women after the childbearing years. In recent studies, the presence of Y-chromosome DNA derived from male fetuses was detected, but DNA from female fetuses could not be investigated in those studies. The present study was undertaken to investigate cellular microchimerism of either male or female origin in DNA from patients with SSc. METHODS: DNA from peripheral blood cells of 63 patients with SSc, 64 healthy individuals, and 24 non-SSc disease controls was examined by polymerase chain reaction analysis of HLA-Cw antigens. RESULTS: Cellular microchimerism of either male or female origin was detected in 41 of 63 SSc patients (65%), in contrast to 18 of 64 normal controls (28%) (chi2 = 15.98, Pcorr = 0.00006) and 8 of 24 disease controls (33%)(chi2= 5.89, Pcorr, = 0.015). CONCLUSION: These findings support the hypothesis that microchimeric cells persisting in the circulation or tissues of SSc patients could be involved in disease pathogenesis by initiating a graft-versus-host-like reaction.

Arthritis, Rheumatoid↗

PubMed2000

Inhibition of type I collagen gene expression in normal and systemic sclerosis fibroblasts by a specific inhibitor of geranylgeranyl transferase I.

OBJECTIVE: To examine the effects of specific inhibition of geranylgeranyl transferase I on the expression of types I and III collagen genes in normal and systemic sclerosis (SSc) dermal fibroblasts in vitro. METHODS: Fibroblasts from 2 normal subjects and 4 SSc patients were incubated with 2-10 microM of GGTI-298, a specific geranylgeranyl transferase inhibitor. Type I collagen and fibronectin production were determined by enzyme-linked immunosorbent assay. Steady-state messenger RNA (mRNA) levels for alpha1(I), alpha2(I), and alpha1(III) collagens and fibronectin were assessed by Northern hybridization, and the transcription of the alpha1(I) collagen gene was examined by transient transfections with a reporter construct containing -5.3 kb of the gene. RESULTS: GGTI-298 caused a dose-dependent inhibition of type I collagen production and a reduction in the steady-state levels of alpha1(I), alpha2(I), and alpha1(III) mRNA in normal and SSc cells. A 60-70% inhibition of type I collagen production and a 70-80% reduction in the mRNA levels for alpha1(I), alpha2(I), and alpha1(III) were observed at 10 microM GGTI-298. In contrast, the expression of fibronectin, cyclooxygenase 1, and GAPDH was not affected. The effects on alpha1(I) collagen mRNA resulted from a profound reduction in transcription of the alpha1(I) collagen gene promoter. GGTI-298 did not affect cellular viability or morphology. CONCLUSION: These results demonstrate that specific inhibition of geranylgeranyl prenylation causes a potent and selective inhibition of expression of the genes encoding types I and III collagens, without affecting cellular viability. The findings indicate that inhibition of geranylgeranyl prenylation should be further studied as a potential therapeutic approach for SSc and other fibrosing diseases.

Actins↗

PubMed2000

CCAAT binding transcription factor binds and regulates human COL1A1 promoter activity in human dermal fibroblasts: demonstration of increased binding in systemic sclerosis fibroblasts.

OBJECTIVE: To determine the binding factors that interact with the proximal promoter region of the human type I collagen gene, COL1A1, and to examine their involvement in its transcriptional regulation in normal and systemic sclerosis (SSc) dermal fibroblasts. METHODS: Nuclear extracts from dermal fibroblasts from 4 patients with SSc and 4 age- and sex-matched control individuals were examined by electrophoresis mobility shift assays with a COL1A1 promoter fragment encompassing nucleotides -174 to -50 bp. Supershift assays with antibodies specific to various transcription factors, and competition experiments using consensus, wild-type, or mutated oligonucleotides corresponding to their specific binding sites, were performed. The effects of specific oligonucleotides as "intracellular competitors" were examined by transient transfection experiments in SSc fibroblasts using a COL1A1 construct containing -174 bp of the promoter. RESULTS: The findings demonstrate that the CCAAT binding transcription factor (CBF) binds the proximal CCAAT box located at -100 to -96 bp, but not the distal CCAAT box at -125 to -121 bp, of the human COL1A1 promoter in both SSc and normal fibroblasts. CBF binding activity was 3-5-fold higher in the SSc fibroblasts. Moreover, the promoter activity of the -174-bp COL1A1 construct was decreased by up to 50% when specific oligonucleotides were used as "intracellular competitors." In addition, Sp1 and Sp3 were other transcription factors found to be involved in the formation of the DNA-protein complexes within this region of the COL1A1 promoter. CONCLUSION: These results indicate that the transcription factor CBF binds the human COL1A1 proximal promoter region in human dermal fibroblasts, and its binding activity is higher in SSc fibroblasts.

Base Sequence↗

PubMed2000

Polymorphisms in the IL-1 receptor antagonist gene VNTR are possible risk factors for juvenile idiopathic inflammatory myopathies.

Although HLA-DRB1 and -DQA1 alleles have been associated with adult and juvenile idiopathic inflammatory myopathies (JIIM), they only partially account for the genetic risk for these autoimmune disorders. Because IL-1alpha and IL-1beta, and the anti-inflammatory competitive inhibitor, IL-1 receptor antagonist (IL-1Ra), have been implicated in the pathogenesis of myositis, we assessed the role of variable number tandem repeat (VNTR) polymorphisms of the IL-1Ra gene (IL-1RN) in the aetiology of JIIM: IL-1RN VNTR polymorphisms were performed on 250 JIIM patients and 471 race-matched controls and were correlated with clinical characteristics. The IL-1RN A1 allele, associated with increased proinflammatory activity, was found to be a risk factor for Caucasians with JIIM (96.0% carriage rate versus 90.2% in race-matched controls, Pcorr = 0.037, odds ratio (OR) = 2.5, confidence interval (CI) = 1.1-5.8), but not for African-Americans, in whom the A3 allele was a possible risk factor (7.0% versus 1.1% in race-matched controls, Pcorr = 0.07, OR = 6.5, CI = 1.1-40.3). IL-1RN genotypes did not correlate with circulating levels of IL-1Ra, which were higher in patients than in controls. The polymorphic IL-1RN locus could be the first non-MHC genetic risk factor identified for JIIM, and different alleles may confer susceptibility for different ethnic groups.

Adolescent↗

PubMed1999

Alterations in the regulation of expression of the alpha 1(I) collagen gene (COL1A1) in systemic sclerosis (scleroderma).

At present, the mechanisms that regulate the expression of collagen genes in normal and pathologic fibroblasts are not known. Thus, the detailed study of transcriptional regulation of COL1A1 in SSc cells will increase our current understanding of the pathophysiology of fibrotic diseases. These studies will yield valuable information regarding the important biological process of regulation of collagen gene expression under normal and pathologic conditions, a process that has remained elusive despite intense recent investigations. It is now evident that persistent overproduction of collagen is responsible for the progressive nature of tissue fibrosis in SSc. Up-regulation of collagen gene expression in SSc fibroblasts appears to be a critical event in this process. The coordinate transcriptional activation of numerous collagen genes suggests a fundamental alteration in the regulatory control of gene expression in SSc fibroblasts. Trans-acting nuclear factors which bind to cis-acting elements in enhancer (intronic) and promoter regions of the genes modulate the basal and inducible transcriptional activity of the collagen genes. The identification of the nuclear transcription factors that regulate normal collagen gene expression may provide promising approaches to the therapy of this incurable disease.

Animals↗

PubMed1999

New perspectives on the etiology of systemic sclerosis.

Systemic sclerosis (SSc) is a disease of unknown origin. Although SSc is considered to be an autoimmune disease, recent studies have implicated cellular microchimerism in its pathogenesis. Microchimerism results from the persistence of fetal cells, from prior pregnancies, in the maternal circulation. The demonstration of the presence of fetal CD3+ T cells in the maternal circulation and of fetal cells in affected SSc tissues suggests that microchimerism might cause SSc in certain patients by initiating a graft-versus-host-like response.

Animals↗

PubMed1999

A disease severity scale for systemic sclerosis: development and testing.

OBJECTIVE: To develop and test a severity scale for individual organ involvements in systemic sclerosis (SSc, scleroderma). METHODS: An international study group completed the following tasks: (1) developed a glossary of terms including all pertinent variables for 9 potentially affected organ systems; (2) collected prospective data to determine the feasibility and practicality of each proposed variable; (3) revised the initial list of variables; (4) determined the association of each variable with mortality (a proxy for morbidity) using 579 patients in an existing comprehensive longitudinal scleroderma databank; (5) developed a severity grading scale for each organ system by discussion and consensus; and (6) externally validated the scale using an independent group of 680 patients from the same databank. RESULTS: Nine organ-specific severity scales were developed from 0 (no documented involvement) to 4 (endstage disease). The data required for scale completion are relatively easy and practical for all physicians to obtain. CONCLUSION: This preliminary severity scale will be useful for assessing disease severity status in individual patients both at one point in time and longitudinally. The severity scale will assist in the design and conduct of clinical trials and the comparison of study populations with one another. The scale will serve as a framework for developing a scleroderma disease activity index.

Humans↗