Blasko I, Sztankay A, Lukas P, Grubeck-Loebenstein B
Institute for Biomedical Aging Research of the Austrian Academy of Sciences, Innsbruck.
Exp Clin Endocrinol Diabetes. 2000;108(2):138-41. doi: 10.1055/s-2000-5808.
Impairment of thyroid function has been described in up to 50% of the patients after external irradiation of the neck region as well as after mantle irradiation. In order to assess radiation-induced alterations in cultured thyroid cells, the occurrence of apoptosis and necrosis as well as the expression of thyroid peroxidase (TPO) and of two members of the 70 kD heat shock family, HSP-73 and HSP-72, were analysed following gamma irradiation. Human thyroid epithelial cells (TEC) were purified from surgical tissue specimens, were cultured and irradiated with a single dose of 5 Gy or 50 Gy using Co60 as radioactive source. Analysis was performed 1, 3 and 5 day(s) after irradiation. Apoptosis and necrosis were assessed by DNA staining with propidium iodide and FACS analysis. TPO and HSP expression by SDS-PAGE and Western blotting. The cell viability of TEC was not affected by irradiation and there was no induction of HSP-72, a sensitive indicator of acute cellular stress. Interestingly, the expression of TPO, a key enzyme of thyroid hormone synthesis, decreased significantly in irradiated TEC, while HSP-73 expression remained unchanged. Decreased expression of TPO with a resulting suppression of thyroid hormone synthesis could contribute to an early development of thyroid dysfunction following irradiation. Thus, analysis of thyroid function, even early after external radiation therapy of the neck or after total body irradiation, seems to be indicated.
高达50%的患者在颈部区域接受外照射以及斗篷野照射后出现甲状腺功能损害。为了评估辐射对培养的甲状腺细胞的影响，分析了γ射线照射后细胞凋亡和坏死的发生情况，以及甲状腺过氧化物酶（TPO）和70 kD热休克家族的两个成员HSP - 73和HSP - 72的表达。从手术组织标本中纯化人甲状腺上皮细胞（TEC），进行培养，并用Co60作为放射源给予5 Gy或50 Gy的单次照射剂量。在照射后1天、3天和5天进行分析。通过碘化丙啶DNA染色和流式细胞术分析评估细胞凋亡和坏死情况。通过SDS - PAGE和蛋白质免疫印迹法分析TPO和HSP的表达。TEC的细胞活力不受照射影响，且未诱导出作为急性细胞应激敏感指标的HSP - 72。有趣的是，甲状腺激素合成的关键酶TPO在受照射的TEC中的表达显著降低，而HSP - 73的表达保持不变。TPO表达降低导致甲状腺激素合成受抑制，这可能促使照射后甲状腺功能障碍的早期发展。因此，即使在颈部外照射治疗后或全身照射后的早期，也似乎有必要对甲状腺功能进行分析。
