Dataset Information

Co-ordinate increase in the expression of type I and type III collagen genes in progressive systemic sclerosis fibroblasts.

ABSTRACT: Progressive systemic sclerosis (PSS), is a connective tissue disease characterized by excessive accumulation of collagen in the skin and various internal organs which is due, at least in part, to increased collagen production by PSS fibroblasts. In order to examine the molecular mechanisms responsible for this abnormality, we compared the kinetics of collagen biosynthesis, the intracellular degradation of collagen and the expression of Types I and III procollagen genes between normal and PSS dermal fibroblasts in culture. Two age- and sex-matched normal and PSS dermal fibroblast cell lines were studied. The results showed that the PSS cultures produced higher amounts of collagen than did normal fibroblasts and displayed an abnormal kinetic pattern. Furthermore, the PSS cells showed a slight but statistically significant increase in the fraction of collagen degraded intracellularly when compared with normal cells (23% against 18% respectively). The levels of mRNA for procollagen Types I and III were determined by Northern and dot-blot hybridization with specific cloned cDNA probes for alpha 1(I), alpha 2(I) and alpha 1(III) and it was found that they were 2-3-fold higher for each of the three chains in the PSS cell lines compared with the controls. These findings indicate, therefore, that the overproduction of collagen characteristic of PSS fibroblasts can be largely accounted for by the increased levels of collagen mRNA.

SUBMITTER: Jimenez SA

PROVIDER: S-EPMC1147064 | biostudies-other | 1986 Aug

REPOSITORIES: biostudies-other

ACCESS DATA

Similar Datasets

Project description:ObjectiveThe role of tumor necrosis factor (TNF) in systemic sclerosis (SSc) remains controversial. The present study was undertaken to investigate the influence of TNF receptor (TNFR)-costimulated lymphocytes on collagen expression in fibroblasts.MethodsTNFR expression on mononuclear cells from the dermis and blood of SSc patients was assessed by flow cytometry. Peripheral blood CD3+ lymphocytes were activated with CD3/CD28 beads and costimulated with TNFR-selective variants. Expression of interleukin-6 (IL-6), soluble IL-6 receptor (sIL-6R), IL-10, and IL-13 was detected by enzyme-linked immunosorbent assay or quantitative reverse transcription-polymerase chain reaction. Healthy fibroblasts were incubated with conditioned media from TNFR-costimulated T lymphocytes, and type I collagen expression was quantified.ResultsTNFRI and TNFRII were up-regulated on dermal T lymphocytes from patients with diffuse cutaneous SSc. TNFRII expression correlated with skin thickening. After CD3/CD28 activation, peripheral blood lymphocytes from SSc patients produced more IL-6, sIL-6R, and IL-13 compared to healthy lymphocytes. Costimulation with TNFRI-selective ligands and soluble TNF further increased IL-6 expression, whereas costimulation with TNFRII led to greater release of sIL-6R. IL-10 expression, which normally occurs after TNFRII costimulation, was impaired in SSc T cells. Supernatants of TNF-costimulated SSc lymphocytes induced higher type I collagen expression in fibroblasts, which was partially reversible by dual inhibition of IL-6 and IL-13. Expression of TNFR and IL-6 in the dermis was reversible in a patient who received lymphoablative therapy prior to autologous hematopoietic stem cell transplantation.ConclusionTNF-costimulated T lymphocytes from SSc patients have a propensity to secrete profibrotic cytokines, while the ability to produce IL-10 is weakened. These results suggest that T lymphocytes in SSc support fibrosis, but might lack the capacity to resolve inflammation.

Project description:Functional cytokine networks have been poorly characterized in systemic sclerosis (SSc). While interleukin-17A (IL-17A) is increased in SSc skin and other organs, its role is still debated, particularly considering fibrogenesis. We uncover here a dual function of IL-17A in the presence of transforming growth factor-? 1 (TGF-?), the master pro-fibrotic cytokine. In the one hand, we report an unexpected synergic activity resulting in enhanced production of IL-6 by dermal fibroblasts; in the other hand, a substantial inhibition of type I collagen (col-I) production. IL-17A or TGF-? enhanced the production of IL-6 by 8- to 16-folds when compared to control in healthy donors (HD) and SSc cultures. However, the joint presence of IL-17A and TGF-? resulted in robustly exuberant responses with levels of IL-6 up to 100-folds higher than those observed in untreated cells. Inhibition of NF?B signaling pathway preferentially inhibited the production of IL-6 driven by IL-17A in HD fibroblasts, while inhibition of PI3K preferentially inhibited the production of IL-6 driven by TGF-?. Interestingly, when p38 MAPK was inhibited, substantial reduction of IL-6 production was observed for both IL-17A and TGF-?. Consistently with the inhibition experiments, the combined stimulation of fibroblasts by IL-17A and TGF-? resulted in 1.8-fold increase in p38 MAPK phosphorylation (P?=?0.025), when compared to levels of phosphorylated p38 MAPK induced by IL-17A alone. Furthermore, the enhanced phosphorylation of p38 MAPK in the joint presence of IL-17A and TGF-? was unique among the signaling molecules we examined. As expected, TGF-? induced SMAD2 phosphorylation and col-I production. However, in fibroblasts cultured in the joint presence of TGF-? and IL-17A, SMAD2 phosphorylation was decreased by 0.6-folds (P?=?0.022) when compared to that induced by TGF-? alone. Remarkably, in this condition, the production of col-I and fibronectin was significantly decreased in both HD and SSc. Thus, IL-17A and TGF-? reciprocally influence each other effector functions in fibroblasts. Intracellular molecular switches may favor synergic or antagonistic activities, which are revealed by specific readouts. The implications of these data in the context of SSc are far reaching, particularly in terms of therapeutic approaches since IL-6, IL-17A, and TGF-? are all putative targets of treatment.

Dataset Information

Co-ordinate increase in the expression of type I and type III collagen genes in progressive systemic sclerosis fibroblasts.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets