Increased proto-oncogene expression in peripheral blood T lymphocytes from patients with systemic sclerosis

[Systemic sclerosis (scleroderma) and malignancy]

The association of malignancy with collagen diseases has been a focus of interest. Especially, relation between dermatomyositis and malignancy is well-recognized. I reviewed here about the coexistence of SSc and malignancy in literature. I would like to raise four points as characteristics of the relationship. (1) Special attention should be paid to the patients who is late-onset, with advanced skin sclerosis (ex. Barnett III type) and male. (2) There are three generalized mechanisms of the association. The first is the predisposition of the malignancy on the basis of organ fibrosis, such as pulmonary fibrosis and lung cancer. The second is the nature of paraneoplastic syndrome. Lastly, immunological derangement inherent to SSc might cause carcinogenesis. (3) It has been documented that the interval of the onsets of SSc and breast cancer is extremely short. (4) Longstanding reflux esophagitis and Barrett's esophagus with SSc is suspected to predispose to esophageal carcinoma.

Gender and androgen treatment influence the expression of proto-oncogenes and apoptotic factors in lacrimal and salivary tissues of MRL/lpr mice

The objectives of this study were to (1) determine whether Fas antigen, Fas ligand, p53, and proto-oncogene mRNAs may be detected in lacrimal and submandibular glands of the MRL/lpr mouse model of Sjögren's syndrome, and (2) examine whether gender and androgen or cyclophosphamide therapy influence the mRNA expression of these apoptotic factors. Tissues were obtained from treated or untreated MRL/lpr mice after the onset of disease and processed for the analysis of mRNAs by RT-PCR and Southern blot hybridization. Our results demonstrated that (1) Fas antigen (exons 1-->2 or 3-->7+), Fas ligand, c-myb, c-myc, bcl-2, Bax, p53, and androgen receptor (AR) mRNAs are present in exocrine tissues of MRL/lpr mice; (2) the amounts of c-myb, c-myc, bcl-2, p53, and AR mRNA are higher (P < 0.05) and the level of Fas antigen (exons 1-->2) mRNA is lower (P < 0.05) in lacrimal glands of female compared to male mice. In contrast, the content of c-myb and p53 mRNA is greater (P < 0.05) in submandibular tissues of female relative to those of male mice; and (3) testosterone or cyclophosphamide treatment led to a significant (P < 0.05) decline in the mRNA levels of c-myb, bcl-2, and/or AR, but an increase (P < 0.05) in the mRNA amount of Bax, in lacrimal, but not in salivary, glands of female mice. These findings demonstrate that gender-associated differences exist in the expression of apoptotic factor mRNAs in exocrine tissues of autoimmune mice and that some of these differences appear to be due to the influence of androgens.

Analysis of proteins that interact with the IL-2 regulatory region in patients with rheumatic diseases

In order to investigate transcriptional regulation of lymphokine genes in rheumatic diseases, peripheral blood mononuclear cells from patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and systemic sclerosis (SSc) were analysed for expression of DNA-binding proteins. Nuclear extracts prepared from unstimulated and mitogen-activated cells were studied for their ability to bind to 32P-labelled oligonucleotides containing the AP-1, NF-AT, NF-B and CD28RC sites of the IL-2 promoter. Using gel mobility-shift assay, detection of protein binding to the AP-1 site was reduced in SLE compared with controls. NF-AT binding activity was enhanced in all groups of patients, and was associated with measures of disease activity in RA. In addition, SSc patients showed increased NF-kappa B binding activity. Altered patterns of DNA-binding proteins suggest disturbed intracellular signalling which may contribute to abnormal lymphokine production in rheumatic diseases.

Increased frequency of in vivo hprt gene-mutated T cells in the peripheral blood of patients with systemic sclerosis

OBJECTIVE

Activated T lymphocytes are involved in the pathogenesis of scleroderma (systemic sclerosis, SSc); such cells rapidly divide in vivo and are thus theoretically subject to random mutation more frequently than resting cells. To study whether SSc is associated with rapidly expanding T cell clones the frequency was determined of in vivo mutated T cells (MF) at the hypoxanthine guanine phosphoribosyl transferase (hprt) gene in the peripheral blood from patients with SSc. Specific clinical or serological associations were also investigated.

METHODS

Peripheral blood lymphocytes from 16 healthy individuals and 20 patients with SSc were cultured using an hprt clonal assay; mutated and wild T cell clones were established to assess individual values of T cell MF. T cell clones were further expanded in vitro and their phenotype was determined by standard immunofluorescence technique. Enzyme-linked immunosorbent assays were used for simultaneous measurements of plasma levels of soluble Interleukin-2 receptors (s-IL-2R) and Intercellular adhesion molecule-1 (s-ICAM-1).

RESULT

Mean (SD) value of T cell MF in patients with SSc was 2.5-fold higher than the normal mean (SD) value [10.6 (6.6) x 10(-6) v [4.4 (2.8) x 10(-6), p = 0.0007]. Eleven of 20 patients with SSc (55%) had T cell MF values greater than two SD above the normal mean value. The majority (84%) of mutated T cells had a helper/inducer, memory phenotype while 12% were cytotoxic/suppressor T cells. There was no association between T cell MF and the extent of skin involvement or the duration of Raynaud's phenomenon. High individual T cell MF values were not related to a possible concurrent immune overactivity as assessed by plasma levels of s-IL-2R and s-ICAM-1. Patients with long standing skin disease, however, had almost double T cell MF values than patients with early skin disease [(13.6 (7.4)) x 10(-6) v (7.5 (4.3)) x 10(-6), p = 0.03], suggesting that increased T cell MF in SSc may reflect an ongoing process of chronic in vivo T cell proliferation and/or prolonged survival.

CONCLUSION

Increased in vivo T cell mutation in patients with SSc suggests that excessive division and/or survival of T cell clones contribute to the pathology in SSc; this approach can be used in further investigations to identify the stimulus that is triggering T cell activation in this disease.

Immunologic parameters in systemic sclerosis

BACKGROUND

Immunologic abnormalities seem to play an important role in important role in systemic sclerosis (SSc).

METHODS

We studied the following immune parameters to get more insight into SSc: autoantibodies (antinuclear antibodies (ANA), anti-Scl-70, anticentromere antibodies (ACA) subsets of lymphocyte subpopulations and markers of their activation, as well as serum levels of IL-2, the soluble IL-2 receptor (SIL-2R), IL-6 and its correlation to N-terminal procollagen-III propeptide (P III P), and finally, the IL-6 production by SSc and normal dermal fibroblasts.

RESULTS

In patients with active SSc, we found a reduced number of CD2+ T-lymphocytes and an increase in the expression of T-lymphocyte activation markers such as CD25+ and CD71+, HLA-DR Ia, as well as elevated serum levels of SIL-2LR and IL-6. SSc fibroblasts did not produce more IL-6 than normal fibroblasts in monolayer cultures.

CONCLUSIONS

Our data show that a wide range of immunologic parameters are altered in SSc. In general, T-helper (TH) lymphocytes are activated possibly because of reduced T-suppressor (TS) and natural killer (NK)-cell levels. TH may polyclonally stimulate B cells, which in turn produce higher amounts of autoantibodies. Our findings support the concept that TH cell-derived cytokines/growth factors stimulate matrix protein synthesis by fibroblasts, resulting in generalized fibrosis.

Systemic sclerosis

Systemic sclerosis affects the connective tissue of various organs. It is characterized by alteration of the microvasculature with a dense inflammatory cellular infiltrate, followed by massive deposition of collagen. This review discusses diagnostic criteria, clinical subsets, survival data, clinical evaluation, epidemiology, pathogenesis, immunobiology, genetics, and therapy for systemic sclerosis in adults. Because the diagnosis of systemic sclerosis is most dependent on its cutaneous involvement, knowledge of this is essential in the evaluation and management of patients with this disorder.

Expression of c-myc, c-myb, and c-sis in fibroblasts from affected and unaffected skin of patients with systemic sclerosis

We examined c-sis, c-myc, and c-myb proto-oncogene expression in fibroblasts cultured from affected and unaffected skin of patients with systemic sclerosis (SSc), and from healthy donor skin. Total cellular RNA from cultured dermal fibroblasts was used in slot blot analysis and scanning densitometry or phosphorimaging to quantify steady-state levels of proto-oncogene mRNAs. PDGF B-chain levels in culture supernatants of fibroblasts were determined by ELISA. Our results demonstrate that steady-state levels of c-myc and c-myb mRNA were elevated 1.5- to 5.6-fold in intralesional fibroblasts from SSc patients as compared to other cells examined. Levels of c-sis mRNA and PDGF-B protein were comparable regardless of source. Elevated c-myc and c-myb expression may be indicative of, and may contribute to, fibroblast activation in SSc.

The effect of cisapride on gastro-oesophageal dysfunction in systemic sclerosis: a controlled manometric study

1. Cisapride is a novel prokinetic drug which facilitates or restores motility throughout the gastrointestinal tract. Its mechanism of action is thought to involve enhancement of acetylcholine release in the myenteric plexus of the gut. 2. The effect of intravenous cisapride 10 mg on gastro-oesophageal dysfunction was investigated in 20 patients with systemic sclerosis, using a double-blind, randomised, cross-over, placebo-controlled manometric study design. 3. The increase in lower oesophageal sphincter pressure was significantly higher after cisapride (mean +/- s.e. mean, 8.3 +/- 2.1 cm H2O) than after placebo (mean +/- s.e. mean. 0.1 +/- 0.3 cm H2O) (P less than 0.001). The increase in the number of fundic gastric contractions during the 30 min study period was significantly higher after cisapride (mean +/- s.e. mean, 7.7 +/- 2.3) than after placebo (mean +/- s.e. mean, 0.9 +/- 0.6) (P less than 0.01). 4. No serious clinical adverse effects were observed. 5. The study demonstrates that intravenous cisapride induces a significant increase in lower oesophageal sphincter pressure and in the number of fundic gastric contractions, which may be beneficial in the treatment of scleroderma gastro-oesophageal dysfunction. Further long-term studies of the effect of oral cisapride in patients with systemic sclerosis are warranted.

Abnormalities of T lymphocyte subsets in systemic sclerosis demonstrated with anti-CD45RA and anti-CD29 monoclonal antibodies

T cell subpopulations were assessed by two colour flow cytometry with phycoerythrin conjugated anti-CD45RA and anti-CD29 and fluorescein conjugated anti-CD4 and anti-CD8 monoclonal antibodies, on peripheral blood lymphocytes from 12 patients with systemic sclerosis and from nine control subjects. The percentage of CD4+CD29+ cells was significantly higher in patients with systemic sclerosis than in controls (mean (SEM) 68.8 (3.1) v 47.9 (4.1) respectively). CD4+CD45RA+ cells were not significantly different in patients and controls. CD8+CD29+ and CD8+CD45RA+ subpopulations were significantly higher in patients with systemic sclerosis than in controls (83.0 (3.2) v 58.7 (6.8) and 80.2 (3.0) v 66.9 (3.2) respectively). The increase in the percentage of CD29+ cells suggests an activation of memory cells in patients with systemic sclerosis, which may play an important part in the pathogenesis of the disease.

Primary sclerosing cholangitis associated with systemic sclerosis

Primary sclerosing cholangitis is a chronic inflammatory fibrotic disorder strongly associated with inflammatory bowel disease. Although an association between some inflammatory fibrotic conditions, such as Riedel's thyroiditis and retroperitoneal fibrosis and primary sclerosing cholangitis has been described, to our knowledge there are no reports of primary sclerosing cholangitis in patients with systemic sclerosis. A patient with this combination of conditions is presented and the possible significance of the association discussed.

In vitro identification of a subpopulation of fibroblasts that produces high levels of collagen in scleroderma patients

A subpopulation of scleroderma dermal fibroblasts was identified by flow cytometric analysis. Between 15% and 25% of the cells within the scleroderma fibroblast lines had high levels of cytoplasmic granularity, as identified by side light scatter characteristics. Similar fibroblasts composed less than 3% of the cells within the normal fibroblast lines, although greater numbers could be induced through exposure to soluble factors derived from activated mononuclear cells. The granular subpopulation of fibroblasts produced 2-3 times as much procollagen as did the other fibroblasts. These data support the hypothesis that fibrosis in scleroderma may result in part from the activity of an inherently high procollagen-producing subset of normal fibroblasts that is expanded through exposure to immune cytokines.

c-myc proto-oncogene expression in peripheral blood mononuclear cells from patients with primary Sjögren's syndrome

We examined peripheral blood mononuclear cells (PBMC) from 16 patients with Sjögren's syndrome (SS) and 7 normal control subjects for the expression of the c-myc proto-oncogene. Patients with SS were found to have a significantly increased expression of c-myc messenger RNA compared with normal individuals. No abnormal forms of c-myc RNA were detected in the SS patients. DNA analysis did not show deletion, rearrangement, or amplification in the c-myc proto-oncogene. The methylation status of the c-myc gene in patients with SS was found to be comparable with that of the control subjects. Nuclear run-off assays showed increased transcription of the c-myc gene in some patients but normal transcription in others, suggesting that posttranscriptional mechanisms are also involved in the increased c-myc messenger RNA observed in these patients. Two patients with primary SS and B cell lymphomas were found to have normal c-myc expression in their PBMC. These results demonstrate the presence of activated PBMC in patients with primary SS and delineate some of the mechanisms that are involved at the molecular level. We speculate that increased c-myc expression may represent an early permissive event in the progression toward neoplasia in these patients.

Recombinant interferon-gamma in the treatment of systemic sclerosis

PURPOSE

Recombinant interferon-gamma (IFN-gamma) is a potent and selective inhibitor of collagen production by dermal fibroblasts in vitro and has numerous immunoregulatory activities. We assessed the effects of recombinant IFN-gamma in the treatment of patients with systemic sclerosis.

PATIENTS AND METHODS

Ten patients entered the study and nine completed the six-month study period. Recombinant IFN-gamma was administered once daily for seven days per week by intramuscular injections: 10 micrograms/day for 10 days, 25 micrograms/day for 10 days, 50 micrograms/day for 10 days, and 100 micrograms/day for the next five months.

RESULTS

After the six-month treatment period, a significant improvement, as compared with base-line values, was observed in total skin score, maximal oral opening, range of motion of wrists and elbows, grip strength, functional index, dysphagia, and creatinine clearance. No serious side effects were observed; however, a significant decrease in white blood cell counts and in peripheral blood lymphocytes was noted.

CONCLUSION

These results suggest that recombinant IFN-gamma may be beneficial in the treatment of patients with systemic sclerosis.