Scleroderma fibroblasts constitutively express the long pentraxin PTX3
Posted Mar 13 2011 12:14pm
ABSTRACT
Objective.
PTX3 is a secreted molecule which consists of a C-terminal domain similar to classical pentraxins (e.g. Creactive protein) and of an unrelated Nterminal domain. Unlike the classical pentraxins, PTX3 is expressed in re -sponse to IL-1 and TNF- but not to IL-6. The present study was designed to investigate the expression of PTX3 in normal and scleroderma fibroblasts.
Methods.
Normal and SSc fibroblasts were cultured in the presence and absence of inflammatory cytokines. PTX3 m R N A
expression in fibroblasts was evaluated by Northern analysis. PTX3 protein levels in fibroblast culture medium were estimated by ELISA.
R e s u l t s.
Normal fibroblasts were induced to express high levels of PTX3 mRNA by IL-1 and TNF- but not by other cytokines or growth factors. Scleroderma fibroblasts, unlike normal fibroblasts, constitutively expressed high levels of PTX3 in the absence of deliberate stimulation. The constitutive expression of PTX3 in SSc fibroblasts was not modified by anti-TNF- antibodies or IL-1 receptor antagonist. In contrast, IFN- and TGF- inhibited the constitutive but not the stimulated ex -
pression of PTX3 in SSc fibroblasts.
Objective.
PTX3 is a secreted molecule which consists of a C-terminal domain similar to classical pentraxins (e.g. Creactive protein) and of an unrelated Nterminal domain. Unlike the classical pentraxins, PTX3 is expressed in re -sponse to IL-1 and TNF- but not to IL-6. The present study was designed to investigate the expression of PTX3 in normal and scleroderma fibroblasts.
Methods.
Normal and SSc fibroblasts were cultured in the presence and absence of inflammatory cytokines. PTX3 m R N A
expression in fibroblasts was evaluated by Northern analysis. PTX3 protein levels in fibroblast culture medium were estimated by ELISA.
R e s u l t s.
Normal fibroblasts were induced to express high levels of PTX3 mRNA by IL-1 and TNF- but not by other cytokines or growth factors. Scleroderma fibroblasts, unlike normal fibroblasts, constitutively expressed high levels of PTX3 in the absence of deliberate stimulation. The constitutive expression of PTX3 in SSc fibroblasts was not modified by anti-TNF- antibodies or IL-1 receptor antagonist. In contrast, IFN- and TGF- inhibited the constitutive but not the stimulated ex -
pression of PTX3 in SSc fibroblasts.
Conclusions.
PTX3 is a main feature of activated scleroderma fibroblasts.