Görtz Gina-Eva, Horstmann Mareike, Aniol Barbara, Reyes Buena Delos, Fandrey Joachim, Eckstein Anja, Berchner-Pfannschmidt Utta
Molecular Ophthalmology (G.-E.G., M.H., B.A., A.E., U.B.-P.), Department of Ophthalmology, University of Duisburg-Essen, 45147 Essen, Germany; and Institute of Physiology (B.D.R., J.F.), University of Duisburg-Essen, 45147 Essen, Germany.
J Clin Endocrinol Metab. 2016 Dec;101(12):4834-4842. doi: 10.1210/jc.2016-1279. Epub 2016 Sep 9.
In Graves' ophthalmopathy (GO), inflammation with tissue expansion in a closed compartment like the bony orbit and smoking may cause tissue hypoxia.
In this study, we investigated whether hypoxia-inducible factor-1 (HIF-1) action impacts on tissue remodeling in GO with the aim to identify possible new therapeutic targets.
DESIGN/SETTING/PARTICIPANTS: Orbital fibroblasts (OFs) were derived from GO patients and control (Ctrl) persons. We analyzed HIF-1α levels in response to hypoxia and cigarette smoke extract, as well as HIF-1-dependent vascular endothelial growth factor (VEGF) release and adipogenic differentiation, by using HIF-1α small interfering RNA, or HIF-1 inhibitor BAY 87-2243.
Western blot, real-time PCR, ELISA, and immunohistochemistry were used to analyze HIF-1α, VEGF, CD31, and adiponectin. Adipogenic differentiation was measured with Nile red assay.
Higher HIF-1α levels in OFs were correlated with the clinical activity score of GO patients. Cigarette smoke extract elevated HIF-1α levels. HIF-1-dependent VEGF secretion was enhanced in GO-OF compared to Ctrl-OF, and as an in vivo consequence, we found a higher vessel density in GO tissue than in Ctrl tissue. Hypoxia strongly stimulated HIF-1-dependent adipogenesis and adiponectin release of GO-OF and enhanced TSH receptor-mediated adipogenesis.
Hypoxia impacts on tissue remodeling in GO by stimulating angiogenesis and adipogenesis through activation of HIF-1-dependent pathways in OFs. Our results offer a molecular mechanism for the detrimental influence of smoking on GO and an explanation as to why decompression can improve the outcome of patients. Drug-targeted inhibition of HIF-1/VEGF may provide a therapeutic option to control tissue expansion in GO.
在格雷夫斯眼病（GO）中，像骨眼眶这样的封闭腔室内的炎症伴组织扩张以及吸烟可能导致组织缺氧。
在本研究中，我们调查缺氧诱导因子-1（HIF-1）的作用是否影响GO中的组织重塑，旨在确定可能的新治疗靶点。
设计/地点/参与者：眼眶成纤维细胞（OFs）取自GO患者和对照（Ctrl）个体。我们通过使用HIF-1α小干扰RNA或HIF-1抑制剂BAY 87-2243，分析了缺氧和香烟烟雾提取物刺激下的HIF-1α水平，以及HIF-1依赖性血管内皮生长因子（VEGF）释放和成脂分化情况。
采用蛋白质免疫印迹法、实时聚合酶链反应、酶联免疫吸附测定和免疫组织化学分析HIF-1α、VEGF、CD31和脂联素。用尼罗红测定法检测成脂分化。
OFs中较高的HIF-1α水平与GO患者的临床活动评分相关。香烟烟雾提取物可提高HIF-1α水平。与Ctrl-OF相比，GO-OF中HIF-1依赖性VEGF分泌增强，并且在体内，我们发现GO组织中的血管密度高于Ctrl组织。缺氧强烈刺激GO-OF的HIF-1依赖性脂肪生成和脂联素释放，并增强促甲状腺素受体介导的脂肪生成。
缺氧通过激活OFs中HIF-1依赖性途径刺激血管生成和脂肪生成，从而影响GO中的组织重塑。我们的结果为吸烟对GO的有害影响提供了分子机制，并解释了减压为何可改善患者预后。药物靶向抑制HIF-1/VEGF可能为控制GO中的组织扩张提供一种治疗选择。
