一种类药物拮抗剂抑制 Graves 眼眶成纤维细胞中促甲状腺激素受体介导的 cAMP 产生的刺激作用。
A drug-like antagonist inhibits thyrotropin receptor-mediated stimulation of cAMP production in Graves' orbital fibroblasts.
机构信息
Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-8029, USA.
出版信息
Thyroid. 2012 Aug;22(8):839-43. doi: 10.1089/thy.2011.0520. Epub 2012 Jul 11.
BACKGROUND
Fibroblasts (FIBs) within the retro-orbital space of patients with Graves' disease (GOFs) express thyrotropin receptors (TSHRs) and are thought to be an orbital target of TSHR-stimulating autoantibodies in Graves' ophthalmopathy (GO). Recently, we developed a low molecular weight, drug-like TSHR antagonist (NCGC00229600) that inhibited TSHR activation in a model cell system overexpressing TSHRs and in normal human thyrocytes expressing endogenous TSHRs. Herein, we test the hypothesis that NCGC00229600 will inhibit activation of TSHRs endogenously expressed in GOFs.
METHODS
Three strains of GOFs, previously obtained from patients with GO, were studied as undifferentiated FIBs and after differentiation into adipocytes (ADIPs), and another seven strains were studied only as FIBs. ADIP differentiation was monitored by morphology and measurement of adiponectin mRNA. FIBs and ADIPs were treated with the TSH- or TSHR-stimulating antibody M22 in the absence or presence of NCGC00229600 and TSHR activation was monitored by cAMP production.
RESULTS
FIBs contained few if any lipid vesicles and undetectable levels of adiponectin mRNA, whereas ADIPs exhibited abundant lipid vesicles and levels of adiponectin mRNA more than 250,000 times greater than FIBs; TSHR mRNA levels were 10-fold higher in ADIPs than FIBs. FIBs exhibited higher absolute levels of basal and forskolin-stimulated cAMP production than ADIPs. Consistent with previous findings, TSH stimulated cAMP production in the majority of ADIP strains and less consistently in FIBs. Most importantly, NCGC00229600 reduced both TSH- and M22-stimulated cAMP production in GOFs.
CONCLUSIONS
These data confirm previous findings that TSHR activation may cause increased cAMP production in GOFs and show that NCGC00229600 can inhibit TSHR activation in GOFs. These findings suggest that drug-like TSHR antagonists may have a role in treatment of GO.
背景
格雷夫斯病（GOF）患者眼眶内的成纤维细胞（FIB）表达促甲状腺激素受体（TSHR），被认为是格雷夫斯眼病（GO）中 TSHR 刺激自身抗体的眼眶靶标。最近，我们开发了一种低分子量、类似药物的 TSHR 拮抗剂（NCGC00229600），该拮抗剂在过表达 TSHR 的模型细胞系统和表达内源性 TSHR 的正常人甲状腺细胞中抑制 TSHR 激活。在此，我们检验了这样一种假设，即 NCGC00229600 将抑制 GOF 中内源性表达的 TSHR 的激活。
方法
研究了先前从 GO 患者中获得的三株 GOF，作为未分化的 FIB 进行研究，并在分化为脂肪细胞（ADIP）后进行研究，另外七株仅作为 FIB 进行研究。通过形态学和脂联素 mRNA 的测量监测 ADIP 分化。用 TSH 或 TSHR 刺激抗体 M22 处理 FIB 和 ADIP，无论是否存在 NCGC00229600 和 TSHR 激活，均通过 cAMP 产生进行监测。
结果
FIB 中几乎没有或没有脂滴，脂联素 mRNA 检测不到，而 ADIP 中则含有丰富的脂滴，脂联素 mRNA 的水平比 FIB 高 25 万倍以上；ADIP 中的 TSHR mRNA 水平比 FIB 高 10 倍。FIB 的基础和福司可林刺激的 cAMP 产生水平均高于 ADIP。与先前的发现一致，TSH 刺激大多数 ADIP 株的 cAMP 产生，而在 FIB 中的刺激则不太一致。最重要的是，NCGC00229600 降低了 GOF 中 TSH 和 M22 刺激的 cAMP 产生。
结论
这些数据证实了先前的发现，即 TSHR 激活可能导致 GOF 中 cAMP 产生增加，并表明 NCGC00229600 可抑制 GOF 中的 TSHR 激活。这些发现表明，类似药物的 TSHR 拮抗剂可能在 GO 的治疗中发挥作用。
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