Skin gene expression of biomarkers associated with macrophages (CD14, IL13RA1) and transforming growth factor β activation (SERPINE1, CTGF, OSMR) are prognostic for progressive skin disease in patients with dcSSc.
We genotyped a polymorphism (G-945C) in the promoter of the connective-tissue growth factor (CTGF) gene in 1000 subjects in two groups: group 1, consisting of 200 patients with systemic sclerosis and 188 control subjects; and group 2, consisting of 300 patients with systemic sclerosis and 312 control subjects.
Induction of matrix metalloproteinase-1 by small interfering RNA targeting connective tissue growth factor in dermal fibroblasts from patients with systemic sclerosis.
Connective tissue growth factor (CTGF) has been implicated in the cardiac and kidney complications of type 2 diabetes, and the CTGF-945 G/C polymorphism is associated with susceptibility to systemic sclerosis, a disease characterised by tissue fibrosis.
Our aim was to examine the therapeutic potential of CTGF blockade in a preclinical model of SSc using two approaches: smooth muscle cell fibroblast-specific deletion of CTGF (CTGF knockout (KO)) or a human anti-CTGF monoclonal antibody, FG-3019.
However, mutation of the previously termed TGFbetaRE reduces ccn2 (ctgf) promoter activity in scleroderma fibroblasts to that seen in normal fibroblasts.
Based on these data, we hypothesize that a 2-step process of fibrosis occurs in SSc: that is, TGF-beta induces fibrosis in the early stage and afterwards CTGF acts to maintain tissue fibrosis.
Our investigations revealed that roscovitine coordinately inhibited the expression of collagen, fibronectin, and connective tissue growth factor (CTGF) in normal and SSc fibroblasts.
Although TNFalpha was able to repress TGF-beta-induced CTGF and collagen synthesis both in normal and scleroderma skin fibroblasts, fibroblasts cultured from scleroderma patients were more resistant to TNFalpha as TNFalpha was unable to suppress the basal level of CTGF expression in scleroderma fibroblasts.
Treatment with rMFG-E8 significantly inhibited latent TGFβ-induced expression of type I collagen, α-smooth muscle actin, and CCN2 in SSc fibroblasts (n = 3-8), which suggested that MFG-E8 inhibited activation of latent TGFβ as well as TGFβ signaling via binding to αv integrin.
Moreover, the role of cytokine (interleukin-1β, interleukin-6) and connective tissue growth factor (CTGF) production, and extracellular signal-regulated kinases (ERK) activation in mediating P2X7R-dependent pro-fibrotic effects in SSc fibroblasts was evaluated.
By sampling dermal interstitial fluid using a suction blister device, we show that CTGF levels are greatly elevated in the dermis of scleroderma patients compared with healthy controls and that Iloprost infusion causes a marked decrease in dermal CTGF levels.
Connective tissue growth factor (CCN2) gene expression was significantly reduced and matrix metalloproteinase 1 (MMP1) levels were enhanced after ciprofloxacin treatment to a similar extent in healthy and SSc fibroblasts.
Expression levels of other TGF-β-regulated genes, including SERPINE1 and CTGF, declined (P = 0.049 and P = 0.012, respectively), and a 2-gene, longitudinal pharmacodynamic biomarker of SSc skin disease decreased after fresolimumab treatment (P = 0.0067).
Normal fibroblasts incubated with serum from an SSc-affected patient or with serum from her unaffected MZ twin sister developed the increased expression of COL1A2, SPARC, and CTGF typically seen in SSc fibroblasts.
In conclusion, this study has revealed an important role of cav-1 in mediating TGFβ/Smad1 signaling and CCN2 gene expression in healthy and SSc dermal fibroblasts.