模拟失重对甲状腺滤泡上皮细胞分泌功能和超微结构的影响

Effects of Simulated Microgravity on Secretory Function and Ultrastructure of Follicular Epithelial Cells

目的研究模拟微重力环境对大鼠甲状腺滤泡上皮细胞(FRTL-5)分泌功能和超微结构的影响。方法应用RCCS建立模拟微重力细胞培养系统,将FRTL-5细胞随机分为模拟微重力组(SMG)和正常重力对照组(NG)。经6、12、24、36 h培养后收集2组细胞,检测FRTL-5细胞培养上清液中三碘甲状腺原氨酸(T3)、甲状腺素(T4)、游离三碘甲状腺原氨酸(FT3)、游离甲状腺素(FT4)、甲状腺球蛋白(TG)和甲状腺过氧化物酶(TPO)浓度;观察培养12 h和36 h的FRTL-5细胞超微结构变化。结果 RCCS培养6 h时,SMG组FRTL-5细胞上清液中T4、FT4、FT3水平低于NG组(P <0. 05)。SMG组FRTL-5细胞TG和TPO分泌均高于NG组(P <0. 01),SMG组12 h细胞质内粗面内质网呈扁平囊状,呈扩张状态,线粒体形态及数目正常,细胞膜清晰未损伤; SMG组36 h细胞膜结构及其基质正常,胞质内粗面内质网呈扩张状态,线粒体形态正常但数量减少。结论 RCCS模拟微重力对FRTL-5细胞T4、FT4和FT3分泌代谢、Tg生成及TPO水平有明显影响,同时引起FRTL-5细胞超微结构改变。

Objective To investigate effects of simulated microgravity on secretory function and ultrastructure of follicular epithelial cells FRTL-5.Methods Rotary cell culture system(RCCS)was used to simulate microgravity cell culture environment.Follicular epithelial cells(FRTL-5 cell lines)were randomly divided into simulated microgravity(SM)group and normal gravity(NG)group.Cells in two group were collected after being cultured for 6,12,24 and 36 h respectively,and levels of triiodothyronine(T 3),thyroxine(T 4),free triiodothyronine(FT 3)and free thyroxine(FT 4)in FRTL-5 cell culture supernatant solution were detected,and concentrations of thyroglobulin(TG)and thyroid peroxidase(TPO)were detected by enzyme linked immunosorbent assay(ELISA).Changes of FRTL-5 cell ultrastructures after being cultured for 12 and 36 h were observed.Results The T 4,FT 4 and FT 3 levels in SM group were significantly lower than those in NG group after being cultured for 6 h(P<0.05).TG and TPO secretion levels in SM group were significantly higher than those in NG group(P<0.01).In SM group,rough endoplasmic reticulum within cytoplasm showed thin,flat and capsular shape with extension,and appearance and number of mitochondrion were normal,and cell membrane was clear without injury after being cultured for 12 h;structures and ground substance of cell membrane were normal,and rough endoplasmic reticulum within kytoplasm was extended,and appearance of mitochondrion was normal,but number of mitochondrion was decreased.Conclusion RCCS simulated microgravity may obviously affect secretory and metabolism of T 4,FT 4 and FT 3,TG production and TPO levels,and simultaneously induce changes of ultrastructural organization in FRTL-5 cells.