Division of Pediatric Endocrinology, Mayo Clinic, Rochester, Minnesota 55905, USA.
Thyroid. 2010 Jan;20(1):59-65. doi: 10.1089/thy.2009.0278.
Patients with Graves' ophthalmopathy (GO) have circulating autoantibodies directed against the thyrotropin receptor (TSHR) and elevated levels of the proinflammatory cytokine interleukin-6 (IL-6) in both serum and orbital tissues. We hypothesized that these autoantibodies might increase IL-6 expression and secretion in preadipocyte fibroblasts and adipocytes from patients with GO, and thus directly impact the clinical activity of the disease.
IL-6 mRNA levels were measured in cultures of GO orbital preadipocytes (n = 3) treated during adipocyte differentiation with a monoclonal stimulatory TSHR antibody (M22; 10 ng/mL), IL-6 (1 ng/mL), or TSH (10 U/L). Additionally, levels of IL-6 protein secretion were assessed after adipocyte differentiation in orbital cultures exposed to TSH or M22 for 24 or 48 hours (n = 8). IL-6 mRNA levels were also measured in orbital adipose tissue specimens from well-characterized GO patients (n = 9) and normal individuals (n = 9).
Treatment of GO orbital preadipocyte cultures with IL-6, TSH, or M22 during adipocyte differentiation resulted in increased IL-6 mRNA levels (3.1-fold, 2.9-fold, and 2.7-fold, respectively; p < 0.05). Treatment of orbital cultures with M22 or TSH after adipocyte differentiation enhanced the release of IL-6 protein into the medium at both 24 and 48 hours for TSH (mean 1.9- and 2.3-fold; p = 0.002 and 0.015, respectively) and at 48 hours for M22 (mean 2.0-fold; p = 0.005). In addition, we found mean IL-6 mRNA levels to be significantly increased in GO orbital adipose tissue specimens (10-fold; p < 0.01), primarily attributable to high levels in three of the four patients with clinical activity scores >or=5.
Both TSH and M22 increase IL-6 expression in orbital preadipocyte fibroblasts and IL-6 secretion by mature adipocytes. These results suggest that circulating TSHR autoantibodies in GO might play a direct role in the clinical activity of the disease.
格雷夫斯眼病（GO）患者的血清和眼眶组织中存在针对促甲状腺激素受体（TSHR）的循环自身抗体，以及促炎细胞因子白细胞介素 6（IL-6）水平升高。我们假设这些自身抗体可能会增加 GO 患者前脂肪细胞和成脂细胞中的 IL-6 表达和分泌，从而直接影响疾病的临床活动。
在 GO 眼眶前脂肪细胞的培养物中，在脂肪细胞分化过程中用单克隆刺激性 TSHR 抗体（M22；10ng/mL）、IL-6（1ng/mL）或 TSH（10U/L）处理，测量 IL-6mRNA 水平（n=3）。此外，在暴露于 TSH 或 M22 24 或 48 小时后，评估眼眶培养物中成脂细胞分化后的 IL-6 蛋白分泌水平（n=8）。还测量了来自特征明确的 GO 患者（n=9）和正常个体（n=9）眼眶脂肪组织标本中的 IL-6mRNA 水平。
在脂肪细胞分化过程中，用 IL-6、TSH 或 M22 处理 GO 眼眶前脂肪细胞培养物，导致 IL-6mRNA 水平增加（分别为 3.1 倍、2.9 倍和 2.7 倍；p<0.05）。在脂肪细胞分化后，用 M22 或 TSH 处理眼眶培养物，在 TSH 时分别在 24 小时和 48 小时增强了 IL-6 蛋白释放到培养基中（平均分别为 1.9 倍和 2.3 倍；p=0.002 和 0.015），在 M22 时在 48 小时增强了 IL-6 蛋白释放到培养基中（平均 2.0 倍；p=0.005）。此外，我们发现 GO 眼眶脂肪组织标本中的 IL-6mRNA 水平显著升高（10 倍；p<0.01），主要归因于四个患者中有三个患者的临床活动评分>或=5。
TSH 和 M22 均增加 GO 眼眶前脂肪细胞成纤维细胞中的 IL-6 表达和成熟脂肪细胞中 IL-6 的分泌。这些结果表明，GO 中的循环 TSHR 自身抗体可能在疾病的临床活动中发挥直接作用。
