PURPOSE In Graves' orbitopathy (GO), hyaluronan secreted by orbital fibroblasts contributes to orbital tissue expansion. The goal of this research was to evaluate the potential benefit of 4-methylumbelliferone (4-MU), a hyaluronan synthase (HAS) inhibitor, in primary cultured orbital fibroblasts from Graves' orbitopathy. METHODS We assessed the viability of orbital fibroblasts using a live/dead cell assay. Hyaluronan synthesis was evaluated by enzyme-linked immunosorbent assay (ELISA) and quantitative real-time PCR (qPCR). Adipogenesis was assessed by Oil Red O staining and qPCR of adipogenic transcription factors. RESULTS In orbital fibroblasts treated with 4-MU (up to 1000 μM), cell viability was preserved by 90%. 4-MU significantly inhibited HAS gene expression and hyaluronan production (*P < 0.05). With respect to adipogenesis, 4-MU suppressed the accumulation of lipids and reduced the number of adipocytes, while decreasing expression of adipogenic transcription factors. CONCLUSIONS 4-MU represents a promising new therapeutic agent for GO based on its ability to inhibit hyaluronan production and adipogenesis, without decreasing cell viability.

中文翻译：

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4-甲基伞形酮可抑制Graves眼眶病引起的原代培养的眼眶成纤维细胞中的透明质酸和脂肪形成。

目的在格雷夫斯眼眶病（GO）中，眼眶成纤维细胞分泌的透明质酸有助于眼眶组织的扩张。这项研究的目的是评估透明质酸合酶（HAS）抑制剂4-甲基伞形酮（4-MU）在来自Graves眼病的原代培养眼眶成纤维细胞中的潜在益处。方法我们使用活/死细胞测定法评估了眼眶成纤维细胞的生存能力。通过酶联免疫吸附测定（ELISA）和定量实时PCR（qPCR）评估乙酰透明质酸的合成。通过油红O染色和成脂转录因子的qPCR评估成脂。结果在用4-MU（至多1000μM）处理的眼眶成纤维细胞中，细胞活力得以保留90％。4-MU显着抑制HAS基因表达和透明质酸生成（* P <0.05）。关于脂肪形成，4-MU抑制脂质的积累并减少脂肪细胞的数量，同时降低脂肪形成转录因子的表达。结论4-MU代表了一种有前途的新的GO治疗药物，因为它具有抑制透明质酸产生和脂肪生成而不降低细胞活力的能力。