Ollis C A, Hill D J, Munro D S
Department of Medicine, University of Sheffield, Northern General Hospital.
J Endocrinol. 1989 Dec;123(3):495-500. doi: 10.1677/joe.0.1230495.
Human thyroid epithelial cells in monolayer culture were found to release radioimmunoassayable insulin-like growth factor-I (IGF-I) over a 48-h culture period in serum-free medium. In the presence of supraphysiological concentrations of TSH (1-100 mU/ml) known to be inhibitory to DNA synthesis by human thyroid cells, the release of IGF-I was found to be inhibited in six thyroid cultures studied. In only one out of the six was IGF-I release increased in the presence of physiological mitogenic concentrations of TSH (0.1-100 microU/ml). Human thyroid fibroblasts, established by long-term culture of thyroid epithelial cells under fibroblast-selective conditions, also secreted IGF-I which was unaffected by the presence of TSH at both low and high concentrations. Using a monoclonal antibody against human IGF-I, monolayer cultures of both human thyroid epithelial cells and human thyroid fibroblasts showed positive immunocytochemical staining for IGF peptide. However, fixed sections of intact thyroid tissue only showed positive staining for IGF peptide associated with the fibrous layers surrounding the thyroid follicle, with no staining of the follicular epithelial cells. The growth of human thyroid epithelial cells was also found to be increased by IGF-I (25-100 ng/ml) added in medium plus 1% fetal calf serum as assessed by the incorporation of [3H]thymidine into DNA. In the presence of a monoclonal antibody to IGF-I the increase in [3H]thymidine uptake in response to IGF-I was abolished as was that seen in response to TSH.(ABSTRACT TRUNCATED AT 250 WORDS)
在无血清培养基中，单层培养的人甲状腺上皮细胞在48小时培养期内可释放能通过放射免疫分析检测的胰岛素样生长因子-I（IGF-I）。在所研究的六种甲状腺培养物中，已知超生理浓度的促甲状腺激素（TSH，1 - 100 mU/ml）对人甲状腺细胞的DNA合成有抑制作用，此时IGF-I的释放受到抑制。在六种培养物中，只有一种在生理促有丝分裂浓度的TSH（0.1 - 100 μU/ml）存在时，IGF-I释放增加。通过在成纤维细胞选择性条件下长期培养甲状腺上皮细胞建立的人甲状腺成纤维细胞，也分泌IGF-I，其不受低浓度和高浓度TSH的影响。使用抗人IGF-I单克隆抗体，人甲状腺上皮细胞和人甲状腺成纤维细胞的单层培养物对IGF肽均呈现阳性免疫细胞化学染色。然而，完整甲状腺组织的固定切片仅显示与甲状腺滤泡周围纤维层相关的IGF肽阳性染色，滤泡上皮细胞无染色。在添加1%胎牛血清的培养基中加入IGF-I（25 - 100 ng/ml），通过[³H]胸苷掺入DNA评估，发现人甲状腺上皮细胞的生长增加。在存在IGF-I单克隆抗体的情况下，对IGF-I反应的[³H]胸苷摄取增加以及对TSH反应的增加均被消除。（摘要截短于250字）
