Serum levels of matrix metalloproteinase-13 in patients with eosinophilic fasciitis.

Matrix metalloproteinase-13 (MMP-13), a member of the collagenase family, has been implicated in the pathogenesis of connective tissue diseases characterized by extracellular matrix remodeling. Since serum MMP-13 levels reflect disease severity of systemic sclerosis and localized scleroderma, we evaluated the clinical significance of serum MMP-13 levels in eosinophilic fasciitis (EF). All the EF patients had serum MMP-13 levels lower than the mean - 2SD of healthy controls. Serum MMP-13 levels were also significantly decreased in EF patients compared with diffuse cutaneous systemic sclerosis, limited cutaneous systemic sclerosis, and generalized morphea patients. Although serum MMP-13 levels did not reflect any clinical and serological features of EF, these results indicate that MMP-13 may be involved in the development of this disease.

Elevated MMP-7 levels in patients with systemic sclerosis: correlation with pulmonary involvement.

BACKGROUND: Fibrosis is characterized by an excessive accumulation of connective tissue because of an imbalance between synthesis and degradation of extracellular matrix proteins. Systemic sclerosis (SSc) is a prototypic chronic inflammatory disease leading to a severe fibrosis of the skin and many internal organs. QUESTIONS ADDRESSED: We investigated whether serum MMP-7 levels reflect the activity of the fibrotic reaction in systemic sclerosis. EXPERIMENTAL DESIGN: Serum samples were obtained from 123 patients with systemic sclerosis. MMP-serum levels of all patients with SSc were compared with age-matched healthy controls. RESULTS: Significantly increased median serum MMP-7 levels were found in patients with SSc when compared with controls. The median MMP-7 serum level of patients with lung fibrosis (LF) was significantly higher compared with those without LF. Accordingly, patients with dyspnea and DLCO (diffusion capacity of the lung for carbon monoxide) levels below 60% showed significantly higher median MMP-7 levels. CONCLUSIONS: Elevated MMP-7 levels are associated with an advanced stage of SSc and LF. These data suggest that in SSc MMP-7 is involved in the process of fibrotic tissue remodelling.

Fox-2 protein regulates the alternative splicing of scleroderma-associated lysyl hydroxylase 2 messenger RNA.

OBJECTIVE: Scleroderma (systemic sclerosis [SSc]) is a complex connective tissue disorder characterized by hardening and thickening of the skin. One hallmark of scleroderma is excessive accumulation of collagen accompanied by increased levels of pyridinoline collagen crosslinks derived from hydroxylysine residues in the collagen telopeptide domains. Lysyl hydroxylase 2 (LH2), an important alternatively spliced enzyme in collagen biosynthesis, acts as a collagen telopeptide hydroxylase. Changes in the pattern of LH2 alternative splicing, favoring increased inclusion of the alternatively spliced LH2 exon 13A, thereby increasing the levels of the long transcript of LH2 (LH2[long]), are linked to scleroderma disease. This study was undertaken to examine the role played by RNA binding protein Fox-2 in regulating exon 13A inclusion, which leads to the generation of scleroderma-associated LH2(long) messenger RNA (mRNA). METHODS: Phylogenetic sequence analysis of introns flanking exon 13A was performed. A tetracycline-inducible system in T-Rex 293 cells was used to induce Fox-2 protein, and endogenous LH2(long) mRNA was determined by reverse transcriptase-polymerase chain reaction. An LH2 minigene was designed, validated, and used in Fox-2 overexpression and mutagenesis experiments. Knockdown of Fox-2 was performed in mouse embryonic fibroblasts and in fibroblasts from SSc patients. RESULTS: Overexpression of Fox-2 enhanced the inclusion of exon 13A and increased the generation of LH2(long) mRNA, whereas knockdown of Fox-2 decreased LH2(long) transcripts. Mutational analysis of an LH2 minigene demonstrated that 2 of the 4 Fox binding motifs flanking LH2 exon 13A are required for inclusion of exon 13A. In early passage fibroblasts derived from patients with scleroderma, the knockdown of Fox-2 protein significantly decreased the endogenous levels of LH2(long) mRNA. CONCLUSION: Our findings indicate that Fox-2 plays an integral role in the regulation of LH2 splicing. Knockdown of Fox-2 and other methods to decrease the levels of fibrosis-associated LH2(long) mRNA in primary scleroderma cells may suggest a novel approach to strategies directed against scleroderma.

Genetic polymorphisms of CYP2D6 oxidation in patients with systemic sclerosis.

BACKGROUND: Involvement of genetic and environmental factors in the pathogenesis of scleroderma has contributed to a number of studies whose aim is to elucidate the way in which xenobiotics exert effects on the occurrence of autoimmune processes resulting in development of systemic sclerosis (SSc). OBJECTIVE: The study dealt with the evaluation of the genetically determined polymorphism of CYP2D6, one of the phase I drug metabolizing isoenzymes, in patients suffering from SSc. Usefulness of the CYP2D6 genotype examination and prevalence of CYP2D6 gene mutation in light of susceptibility to SSc development were assessed. METHODS: Forty-three patients with SSc and 129 healthy volunteers were included in the study. Of the 43 patients with SSc, 17 fulfilled the criteria of diffuse SSc (dSSc) and 26 of limited SSc (lSSc). The determination of the CYP2D6 oxidative polymorphism was performed with the PCR-RFLP method. RESULTS: Relative risk of SSc development for particular genotype carriers expressed by the odds ratio (OR) was statistically significantly higher for subjects with CYP2D6*1/CYP2D6*4 (OR = 4.8; P < 0.001). A statistically significant correlation between the CYP2D6*4 allele prevalence and the risk for developing SSc was found (OR = 2.6; P = 0.0002). CONCLUSION: Higher prevalence of the CYP2D6*4 mutated alleles in patients with SSc and the obtained OR values suggest that this mutation has the effect of increasing SSc morbidity rate.