Excessive fluoride exposure decreased the expression of tight junction protein zonula occludens-1, in human vascular endothelial cells / 中华地方病学杂志

ABSTRACT

Objective To observe the effect of excessive fluoride exposure on expression of tight junction protein zonula occludens-1 (ZO-1) in human vascular endothelial cells and to explore the mechanism.Methods Human umbilical vein endothelial cells (HUVECs) were cultured in vitro.Group design was adopted.Groups of 0.0 (control group) and 0.4,0.8,1.2 mg/L fluoride treatment groups (low,medium and high dose groups) and insulin-like growth factor-1 (IGF-1) group [before adding 1.2 mg/L fluoride ion (F-),100 nmol/L of IGF-1 was added in advance for 2 hours] were set up respectively.Each group of cells was cultured for 24 h to extract cellular proteins.The expression of ZO-1,phosphatidylinositol kinase (PI3K),protein kinase B (AKT) and phosphorylated AKT (p-AKT)were detected and analyzed by Western blotting.Results The expression of intracellular ZO-1 (0.063 ± 0.002,0.043 ± 0.007,0.039 ± 0.004,0.028 ± 0.007) decreased obviously with gradual increase of F-concentration in cultural medium (F =21.36,P ＜ 0.01).And the expressions of ZO-1 in all three fluorine groups were clearly lower than that in the control group (P ＜ 0.05).At the same time,the expression of ZO-1 in high fluorine group was significantly lower than those in other fluorine groups (P ＜ 0.05).There were significant differences in the expression of PI3K (0.032 ± 0.004,0.031 ± 0.002,0.017 ± 0.001,0.017 ± 0.005) and p-AKT/AKT (0.745 ± 0.046,0.806 ±0.007,0.666 ± 0.058,0.641 ± 0.040) among all groups (F =20.38,9.57,P ＜ 0.01 or ＜ 0.05).The expressions of PI3K and p-AKT/AKT in high fluorine group were obviously lower than those of control and mild fluorine groups,and p-AKT/AKT in moderate fluorine group was clearly lower than that of mild fluorine group (P ＜ 0.05).After pretreatment with IGF-1,the expression of ZO-1 (0.055 ± 0.015) increased significantly compared to that of high fluorine group (P ＜ 0.05).Conclusion Excessive fluoride exposure has decreased the expression of ZO-1 in HUVECs through the PI3K/AKT signaling pathway.