Decreased MMP-9 activity in the serum of patients with diffuse cutaneous systemic sclerosis

IL-25 participates in keratinocyte-driven dermal matrix turnover and is reduced in Systemic Sclerosis epidermis

OBJECTIVES

Evidence shows that dysfunctional SSc keratinocytes contribute to fibrosis by altering dermal homeostasis. Whether interleukin-25 (IL-25), an IL-17 family member regulating many epidermal functions, takes part in skin fibrosis is unknown. Here we address the role of IL-25 in skin fibrosis.

METHODS

The expression of IL-25 was evaluated by immunofluorescence and in situ hybridization in 10 SSc and 7 healthy donors (HD) skin biopsies. Epidermal equivalents (EE) reconstituted by primary HD keratinocytes were used as a model to study transcriptomic changes induced by IL-25 in the epidermis. RNA expression profile in EE was characterized by RNAseq. The conditioned medium (CM) from primary SSc and HD keratinocytes primed with IL-25 was used to stimulate fibroblasts. IL-6, IL-8, MMP-1, type-I collagen (col-I), and fibronectin production by fibroblasts was assessed by ELISA.

RESULTS

SSc epidermis expressed lower levels of IL-25 compared with HD. In EE, IL-25 regulated several molecular pathways related to wound healing and ECM remodeling. Compared with control CM, the CM from IL-25-primed keratinocytes enhanced the fibroblast production of MMP-1, IL-6, IL-8, but not of Col-I nor fibronectin. However, IL-25 significantly reduced the production of Col-I when applied directly to fibroblasts. The activation of keratinocytes by IL-25 was receptor-dependent and evident after a very short incubation time (10 min), largely mediated by IL-1, suggesting enhanced and specific release of preformed mediators.

CONCLUSIONS

These results show that IL-25 participates to skin homeostasis and its decreased expression in SSc may contribute to skin fibrosis by favoring ECM deposition over degradation.

Investigation of the Expression of Inflammatory Markers in Oral Biofilm Samples in Patients with Systemic Scleroderma and the Association with Clinical Periodontal Parameters-A Preliminary Study

BACKGROUND

Systemic scleroderma (SSc) has multiple orofacial effects. The aim of this study was to analyze the expression of inflammatory mediators in biofilm samples. It was hypothesized that different expression levels and clinical associations might be drawn.

METHODS

A total of 39 biofilm samples from group 1 = SSc and group 2 = healthy control were examined for the expression levels of interleukin (IL)-2,-6, and -10; matrix metalloprotease (MMP)-9; and surface antigens CD90 and CD34 by quantitative real-time PCR and clinical parameters. Relative quantitative (RQ) gene expression was determined using the ∆∆CT method.

RESULTS

The mean bleeding on probing values (p = 0.006), clinical attachment loss (CAL) (p = 0.009), gingival recession (p = 0.020), limited mouth opening (p = 0.001) and cervical tooth defects (p = 0.011) were significantly higher in group 1. RQ expressions of IL-2 and CD34 were significantly lower, IL-6, MMP-9, and CD90 were significantly higher. There was a significant positive correlation of IL-6/MMP-9 and negative correlation of mouth opening/CAL and IL-6/CAL.

CONCLUSION

Different expression levels of IL-2, IL-6, MMP-9, CD34 and CD90 were detected in biofilm samples from patients with SSc compared to control. An immunological correlation to the clinical parameters of mouth opening and CAL was shown; thus, we conclude that SSc might have an impact on periodontal tissues.

Toll-like receptor-mediated, enhanced production of profibrotic TIMP-1 in monocytes from patients with systemic sclerosis: role of serum factors

Objectives

To investigate whether monocytes contribute to matrix deposition in systemic sclerosis (SSc) by production of tissue-inhibitor of metalloproteinase-1 (TIMP-1).

Methods

Matrix metalloproteinase-1 (MMP-1) and TIMP-1 expression and secretion were measured by qRT-PCR and ELISA in circulating monocytes from patients with SSc, patients with rheumatoid arthritis (RA) and healthy controls (HC) and in healthy monocytes cultured in the presence of SSc or HC serum samples. Production of TIMP-1 was determined in response to a panel of Toll-like receptor (TLR) agonists and MyD88 inhibitory peptide. The functional effect of conditioned media from SSc and HC serum samples or TLR8-stimulated monocytes was studied in an MMP-1 activity assay.

Results

TIMP-1 production by monocytes was upregulated in patients with SSc compared with patients with RA and HC. Incubation of HC monocytes with SSc serum samples resulted in functionally active TIMP-1 production. However, pretreatment with MyD88 inhibitor, but not control peptide, decreased TIMP-1 secretion. TIMP-1 production was significantly stronger when SSc and HC monocytes were stimulated with TLR8 (ssRNA) agonist, but the response was more pronounced in SSc monocytes. TIMP-1 production after TLR stimulation was also strongly reduced in the presence of MyD88 inhibitory peptide or in the monocytes isolated from a patient with a genetic TLR signalling defect. MMP-1 activity was significantly inhibited in media from serum samples or TLR8-stimulated monocytes indicative of functional TIMP activity.

Conclusions

This study demonstrates profibrotic properties of circulating monocytes from patients with SSc and a key role for TLR signalling, particularly TLR8, in TIMP-1 secretion and matrix remodelling.

Clinical outcomes of bosentan in pulmonary arterial hypertension do not correlate with levels of TIMPs

BACKGROUND

Matrix metalloproteinases (MMP) and their inhibitors, tissue inhibitors of metalloproteinases (TIMP), are involved in tissue inflammation and fibrotic processes. Treatment with bosentan has been shown to improve the clinical outcome of patients with pulmonary arterial hypertension (PAH) with and without association with systemic sclerosis (SSc), and also to modulate the serum levels of matrix metalloproteases-9. We measured TIMP-1 and TIMP-2 in the serum of patients with SSc with and without PAH treated with long-term bosentan compared with healthy donors (HD).

MATERIALS AND METHODS

Serum samples from HD (n = 16) and patients with SSc (n = 35), including patients with SSc without PAH (n = 23) and patients with PAH (n = 12), were analyzed using enzyme-linked immunosorbent assays (ELISAs) for total TIMP-1 and TIMP-2.

RESULTS

Both mean TIMP-1 and TIMP-2 levels were significantly increased in patients with SSc compared with HD, but no differences were observed between patients with SSc with and without PAH. In the eight bosentan-treated patients, TIMP-1 and TIMP-2 levels did not change during 1 year of treatment, while bosentan increased the 6-min walking distance by 136 meters after 1 year, as well as clinical outcomes.

CONCLUSIONS

Increased levels of TIMP-1 and TIMP-2 in patients with SSc compared with HD suggest that the inhibition of proteolysis allows the accumulation of ECM proteins. As bosentan does not stimulate TIMPs, it appears to favour proteolytic imbalance and to increase the turnover of ECM proteins.

Matrix metalloproteinase-9 and autoimmune diseases

Matrix metalloproteinases (also named matrixin or MMPs) are a major group of enzymes that regulate cell-matrix composition by using zinc for their proteolytic activities. They are essential for various normal biological processes such as embryonic development, morphogenesis, reproduction tissue resorption, and remodeling. Metalloproteinases also play a role in pathological processes including inflammation, arthritis, cardiovascular diseases, pulmonary diseases and cancer. Herein we review the involvement of MMP-9 in a variety of autoimmune diseases including systemic lupus erythematosus, Sjogren's syndrome, systemic sclerosis, rheumatoid arthritis, multiple sclerosis, polymyositis and atherosclerosis. MMP-9 plays either a primary or secondary role in each one of those autoimmune diseases by its up or down-regulation. It is not expressed constantly but rather is induced or suppressed by many regulating molecules. This feature of MMP-9 along with its involvement in disease pathogenesis turns it into a target for therapy of autoimmune diseases.

The effect of bosentan on matrix metalloproteinase-9 levels in patients with systemic sclerosis-induced pulmonary hypertension

OBJECTIVE

Systemic sclerosis (SSc) is an autoimmune disease that can potentially involve all tissues and organs of the human body. Based on the extent of the disease and organ involvement, different subsets of patients and organ involvement, different subsets of patients have been identified and several classifications proposed have been identified and several classifications proposed aiming to better stratify affected patients. The occurrence aiming to better stratify affected patients. The occurrence of pulmonary arterial hypertension (PAH), characterized of pulmonary arterial hypertension (PAH), characterized by altered tissue remodelling of the entire vessel wall, is the most severe complication that influences prognosis and survival. The molecular basis underlying the vascular damage is not yet known, but a family of enzymes named matrix metalloproteinases (MMPs), with a proteolytic activity towards several extra-cellular matrix (ECM) components, is likely to be involved. Recently, a dual inhibitor of endothelin-1, bosentan, has been successfully evaluated in clinical trials in PAH patients.

RESEARCH DESIGN AND METHOD

The aim of this study is to investigate the expression of MMP-2 and MMP-9 in the serum of different subsets of SSc patients, and in patients treated with bosentan. Thirty-five Caucasian patients with SSc were enrolled in the study, 12 of whom were found to have isolated PAH assessed by Doppler echocardiography. Eight patients fully met the inclusion criteria and were eligible for therapy with bosentan given at the dosage of 62.5 mg twice daily for 4 weeks followed by 125 mg twice daily for 50 weeks(15). The remaining patients (4/12) initiated bosentan therapy for a few weeks and, therefore, were considered at the baseline level only. Serum samples were analysed by gelatine zymography.

RESULTS

The results suggest that MMP-9 but not MMP-2 is differently expressed according to the degree of organ involvement. In particular, MMP-9 serum levels are significantly decreased in PAH with respect to other subsets of SSc patients. Moreover, in bosentan-treated patients, after 12 months of therapy MMP-9 significantly (p < 0.05) increased and correlated with an improved clinical outcome, as measured by the '6-minutes walking' test.

CONCLUSIONS

This is the first time that MMP-9 serum levels are reported to be down-regulated in PAH patients and up-regulated following bosentan treatment. Whether MMP-9 has a pathogenetic role in the vascular damage observed in PAH patients or it is a marker of bosentan effectiveness is not yet known. However, MMP-9 may be an important molecule that needs further investigation in SSc patients to better define its role.

Elevated matrix metalloproteinase-9 in patients with systemic sclerosis

Matrix metalloproteinase-9 (MMP-9) has been implicated in the pathogenesis of cancer, autoimmune disease, and various pathologic conditions characterized by excessive fibrosis. In this study, we investigated the expression of MMP-9 and its clinical significance in systemic sclerosis (SSc). The patients (n = 42) with SSc had higher concentrations of MMP-9 and of tissue inhibitor of metalloproteinase-1 (TIMP-1) and a higher ratio of MMP-9 to TIMP-1 in sera than healthy controls (n = 32). Serum MMP-9 concentrations were significantly higher in the diffuse type (n = 23) than the limited type of SSc (n = 19). Serum concentrations of MMP-9 correlated well with the degree of skin involvement, as determined by the Rodnan score and with serum concentrations of transforming growth factor β. Moreover, dermal fibroblasts from patients with SSc produced more MMP-9 than those from healthy controls when they were stimulated with IL-1β, tumor necrosis factor α, or transforming growth factor β. Such an increase in MMP-9 production was partially blocked by treatment with cyclosporin A. In summary, the serum MMP-9 concentrations were elevated in SSc patients and correlated well with skin scores. The increased MMP-9 concentrations may be attributable to overproduction by dermal fibroblasts in SSc. These findings suggest that the enhanced production of MMP-9 may contribute to fibrogenic remodeling during the progression of skin sclerosis in SSc.