ABSTRACT
PURPOSE: To investigate the role of gangliosides in the differentiation of orbital fibroblasts into adipocytes, a component in the pathogenesis of Graves' ophthalmopathy. METHODS: Orbital tissues were obtained during orbital surgery for subjects without Graves' ophthalmopathy or other inflammatory orbital disease, and orbital fibroblasts were primarily cultured from each obtained tissue. Morphological examination of orbital fibroblasts was performed after treatment with commercially available gangliosides mixture (Gmix) comprised of several subtypes. To determine the effect of Gmix on the differentiation of orbital fibroblasts into adipocytes and the differentiation-related genes, Oil Red-O staining and RT-PCR were performed. RESULTS: The treatment with Gmix induced the morphological changes, which at least in part were explained with the differentiation of orbital fibroblasts into adipocytes in accordance with the increase of mRNA level of genes known to be related to adipogenesis, whereas dermal fibroblasts and preadipocytes were irresponsive to the same treatment. CONCLUSIONS: The results from the present study suggest gangliosides may have a role in pathologic mechanisms of Graves' ophthalmopathy by the induction of differentiation of orbital fibroblasts into adipocytes.