氟对猪甲状腺原代培养细胞甲状腺过氧化物酶活性及mRNA表达的影响

Effect of fluoride on thyroid peroxidase activity and mRNA expression in porcine thyrocytes

目的探讨氟对猪甲状腺原代培养细胞甲状腺过氧化物酶（TPO）活性及mRNA表达的影响。方法用原代培养的猪甲状腺细胞，按氟化钠（NaF）剂量不同分为：0（对照）、40、80、160mg／L组。甲状腺细胞培养48h后，采用吖啶橙染色观察甲状腺细胞形态学改变，改良愈创木酚法检测TPO活性，RT-PCR法测定TPOmRNA的表达水平。结果培养48h后，80、160mg／L组吖啶橙染色可见凋亡小体及大量漂浮细胞、碎片。0、40、80、160mg／L组TPO活性[（3．103±0．090）、（1．944±0．025）、（1．361±0．008）、（0．668±0．026）U／L]随着染氟剂量的升高而明显降低，组间比较差异有统计学意义（F=1563．864，P〈0．05），TPO活性与染氟剂量呈负相关（r=-0．955，P〈0．05）。4组TPO mRNA表达水平（0．947±0．013、0．634±0．018、0．448±0．028、0．210±0．009）也随着染氟剂量的升高而明显降低，组间比较差异有统计学意义（F=2713．855，P〈0．05）。结论氟可能是通过抑制TPO活性及TPO mRNA的表达来影响甲状腺功能。

Objective To approach the effect of fluoride on the expression of thyroid peroxidase （TPO）activity and TPO mRNA in primary porcine thyrocytes. Methods Purified cultured porcine thyrocytes was made into sodium fluoride model, and were divided according to the final concentration of NaF into 0 （control group）, 40, 80, 160 mg/L. After exposed to NaF for 48 h, the morphology of the porcine thyrocytes was investigated with acridine orange staining method, TPO activity was measured with upgrade guaiacol method and RT-PCR method was used to detect the ratio of TPO/β-actin. Results The major changes included apoptotic bodies and cell fragments in the 80, 160 mg/L groups under phase contrast microscope. With the increasing dose of fluoride, TPO activity, being（3.103 ± 0.090）, （1.944 ± 0.025）, （1.361 ± 0.008）, （0.668 ± 0.026）U/L, respectively, had obviously lowered with a statistical significance compared between the groups（F = 1563.864, P 〈 0.05）. The TPO activity had a negative correlation with the dose of fluoride（r = - 0.955 ,P 〈 0.05）. With the dose of fluoride increasing, the expression of TPO mRNA had obviously lowered, being （0.947 ± 0.013）, （0.634 ± 0.018）, （0.448 ± 0.028） and （0.210 ± 0.009） with a statistical significance in group comparison （F = 2713.855, P 〈 0.05）. Conclusion Fluoride affects the thyroid via inhibiting TPO activity and expression of TPO mRNA.