17β-雌二醇对人甲状腺干细胞增殖影响的研究

Effect of 17β-estradiol on proliferation of human thyroid stem cells

目的 探讨17β-雌二醇对人甲状腺干细胞增殖的影响.方法 采用甲状腺细胞与干细胞原代培养技术,以BrdU ELISA法、RT-PCR与实时定量PCR、免疫荧光技术和Western印迹等方法,检测17β-雌二醇对甲状腺干细胞增殖和雌激素受体（estrogen receptor,ER）表达的影响,观察细胞周期蛋白与丝裂原活化蛋白激酶（MAPK）通路相关蛋白表达的变化.结果 17β-雌二醇可促进甲状腺干细胞增殖,并可维持甲状腺干细胞球的形成.原代甲状腺细胞与甲状腺干细胞均表达ER-d和ER-β,前者ER-α mRNA表达较强（8.85±0.81对1.10±0.35,P＜0.01）.1 nmol/L 17β-雌二醇刺激后,周期素D1表达明显增加,MAPK通路细胞外信号调节激酶（ERK）磷酸化水平明显增加,此作用可被ER拮抗剂ICI 182780阻断.结论 雌激素可促进甲状腺干细胞增殖,雌激素受体可能发挥重要作用,提示雌激素诱导的甲状腺干细胞过度增殖可能与女性甲状腺肿瘤发病增高相关.

Objective To investigate the effect of 17β-estradiol on the proliferation of thyroid stem/ progenitor cells.Methods In thyroid stem/progenitor cells derived from nodular goiters,the effects of 17 β-estradiol on thyrosphere formation,estrogen receptor （ER） expression,cyclin D1 expression,and mitogen activated protein kinase （MPAK） pathway were analysed by BrdU ELISA,conventional and realtime PCR,immunofluorensence staining,and Western blot.Results 17β-estradiol induced thyrosphere formation and proliferation of thyroid stem/ progenitor cells.ER-α and ER-β were expressed in thyroid stem and progenitor cells with higher mRNA expression level of ER-α compared to differentiated thyrocytes （8.85-±0.81 vs 1.10 ±0.35,P＜0.01）.Stimulation by 1 mmol/L 17β-estradiol increased cyclin D1 mRNA expression and ERK phosphorylation levels,which was blocked by an ER antagonist,ICI 182780.Conclusion Estrogen stimulated the growth of stem cells derived from thyroid nodules via estrogen receptor,suggesting the relevance of increased thyroid stem cell proliferation with higher prevalence of thyroid nodules in women.