PURPOSE: Graves' ophthalmopathy (GO) is characterized by the infiltration of immune cells into the orbit, a process in which cytokines play a central role. Orbital fibroblasts are potent producers of cytokines on different stimuli. Recently, the authors showed increased expression of the PDGF-B chain in GO orbital tissue. The dimeric PDGF-BB molecule has been described to activate the NF-kappaB pathway, which is well recognized for its role in regulating cytokine production. This study was conducted to determine the role of PDGF-BB in the production of proinflammatory cytokines by orbital fibroblasts in GO. METHODS: Orbital, lung, and skin fibroblasts were stimulated with PDGF-BB, and cytokine (IL-1beta, IL-6, IL-8, IL-16, CCL2, CCL5, CCL7, TNF-alpha) production was measured by ELISA. Involvement of NF-kappaB activation through PDGF signaling was investigated by electrophoretic mobility shift assay, specific NF-kappaB inhibitors, and the PDGF-receptor kinase inhibitor imatinib mesylate. RESULTS: IL-6, IL-8, CCL2, CCL5, and CCL7 production by orbital fibroblasts was increased by PDGF-BB stimulation, whereas IL-16, IL-1beta, and TNF-alpha production was not affected. PDGF-BB induced NF-kappaB activity in orbital fibroblasts, and both NF-kappaB inhibitors and imatinib mesylate reduced PDGF-BB-induced cytokine production. Similar, but less vigorous, effects of PDGF-BB on cytokine production were observed in lung and skin fibroblasts. CONCLUSIONS: PDGF-BB is a potent inducer of proinflammatory cytokines via the NF-kappaB pathway in orbital fibroblasts, whereas cytokine production by fibroblasts from other anatomic locations showed a moderate response. These data suggest a possible role for PDGF-BB in regulating orbital inflammation in GO and identify the PDGF signaling cascade as a therapeutic target in GO.

PDGF receptor tyrosine kinase, adult, aged, angiogenic factor, article, biosynthesis, cell culture, cytokine, cytology, drug antagonism, drug effect, endocrine ophthalmopathy, enzyme linked immunosorbent assay, female, fibroblast, gel mobility shift assay, human, imatinib, immunoglobulin enhancer binding protein, lung, male, metabolism, middle aged, orbit, piperazine derivative, platelet derived growth factor, platelet derived growth factor BB, platelet derived growth factor receptor, platelet-derived growth factor BB, protein kinase inhibitor, protein tyrosine kinase, pyrimidine derivative, skin
Investigative Ophthalmology & Visual Science
Erasmus MC: University Medical Center Rotterdam

van Steensel, L, Paridaens, A.D.A, Dingjan, G.M, van Daele, P.L.A, van Hagen, P.M, Kuijpers, R.W.A.M, … Dik, W.A. (2010). Platelet-derived growth factor-BB: a stimulus for cytokine production by orbital fibroblasts in Graves' ophthalmopathy. Investigative Ophthalmology & Visual Science, 51(2), 1002–1007. Retrieved from http://hdl.handle.net/1765/19308