Bechtner G, Pötscher C, Gärtner R
Medizinische Klinik, University of Munich, F.R.G.
Thyroidology. 1992 Apr;4(1):1-5.
Basic fibroblast growth factor (bFGF), insulin like growth factor I and II and transforming growth factor beta (TGF-beta) are assumed to be of importance in the paracrine and autocrine regulation of thyroid growth and function. Using in vitro cultures of isolated intact porcine thyroid follicles, we here present data that support a possible autocrine action of bFGF on proliferation, a possible explanation for the observed potentiation of EGF-stimulated growth by IGF-I, and results on the release and regulation of release of TGF-beta. For growth experiments, thyroid follicles (2 x 10(5) cells) were incubated for 6 days followed by cell counting. For the analysis of EGF binding sites, follicles were preincubated with and without IGF-I (10 ng/mL) for 48 h at 37 degrees C, incubated with 125I-EGF (5 nCi/well) and unlabeled EGF (0.1-500 ng/mL) for 24 h at 4 degrees C (2 x 10(5) cells/well); binding characteristics were calculated from Scatchard analysis. The TGF-beta bioactivity in untreated and acid treated media conditioned with thyroid follicles for 3 days (2 x 10(7) cells) was analyzed with a bioassay using mink lung epithelial cells. Basic FGF (0.1-1 ng/mL) dose-dependently stimulated the proliferation of thyroid follicles up to 135.0 +/- 6.1%; this effect was additive with IGF-I (10 ng/mL) but not with EGF (2 ng/mL). The IGF-I (10 ng/mL) just moderately increased proliferation (128.3 +/- 16%), but potentiated EGF (1 ng/mL)-stimulated growth (from 183.0 +/- 11.0% to 314.0 +/- 3.0%).(ABSTRACT TRUNCATED AT 250 WORDS)
碱性成纤维细胞生长因子（bFGF）、胰岛素样生长因子I和II以及转化生长因子β（TGF-β）被认为在甲状腺生长和功能的旁分泌和自分泌调节中起重要作用。利用分离的完整猪甲状腺滤泡进行体外培养，我们在此展示的数据支持bFGF对增殖可能存在自分泌作用，为观察到的IGF-I增强EGF刺激生长提供了一种可能的解释，并给出了TGF-β释放及释放调节的结果。对于生长实验，将甲状腺滤泡（2×10⁵个细胞）孵育6天，然后进行细胞计数。为分析EGF结合位点，滤泡在37℃下用或不用IGF-I（10 ng/mL）预孵育48小时，在4℃下用¹²⁵I-EGF（5 nCi/孔）和未标记的EGF（0.1 - 500 ng/mL）孵育24小时（2×10⁵个细胞/孔）；结合特性通过Scatchard分析计算得出。用貂肺上皮细胞生物测定法分析未处理和经酸处理的、由甲状腺滤泡（2×10⁷个细胞）条件培养3天的培养基中的TGF-β生物活性。碱性FGF（0.1 - 1 ng/mL）剂量依赖性地刺激甲状腺滤泡增殖，最高可达135.0±6.1%；此效应与IGF-I（10 ng/mL）相加，但与EGF（2 ng/mL）不相加。IGF-I（10 ng/mL）仅适度增加增殖（128.3±16%），但增强了EGF（1 ng/mL）刺激的生长（从183.0±11.0%增至314.0±3.0%）。（摘要截短于250字）
