Effects of sodium arsenite on the expression of microRNA-191 and tissue inhibitor of metalloproteinase 3 in L-02 cells / 中华地方病学杂志

ABSTRACT

Objectives To investigate the effects of sodium arsenite (NaAsO2) on the expression ot microRNA-191 (miR-191) and tissue inhibitor of metalloproteinase 3 (TIMP-3) in human normal hepatic cells (L-02 cells).Methods L-02 cells were exposed to different doses of NaAsO2 [0 (control group),5,25,50 and 75 μmol/L]for 24 h,or treated with 5 and 25 μmol/L NaAs02 for 0 (control group),12,24 and 48 h.The miR-191 inhibitor was used to suppress the expression of miR-191.qRT-PCR was performed to detect the expression level of miR-191 and TIMP-3 mRNA,and the protein level of TIMP-3 was analyzed by Western blotting.Results Dose-effect studyThere were significant differences in the expressions of miR-191,TIMP-3 mRNA and protein between the 5 groups (F =85.674,20.952,123.393,all P ＜ 0.05).The expressions of miR-191 in all groups (1.702 ± 0.124,2.077 ±0.234,2.145 ± 0.105,2.003 ± 0.077) were higher than that of control group (0.990 ± 0.035,all P ＜ 0.05);the mRNA expressions of TIMP-3 in 25,50,75 μmol/L groups (0.848 ± 0.067,0.804 ± 0.081,0.813 ± 0.076) were all lower than that of control group (0.996 ± 0.007,all P ＜ 0.05),but there was no significant difference in the mRNA expression of TIMP-3 between the 5 μmol/L group and control group (0.939 ± 0.133 vs 0.996 ± 0.007,P＞ 0.05),and the protein expressions of TIMP-3 in all groups (0.846 ± 0.093,0.611 ± 0.123,0.554 ± 0.098,0.529 ± 0.067) were lower than that of control group (1.006 ± 0.003,all P ＜ 0.05).Time-effect studythere were significant differences in the expressions of miR-191,TIMP-3 mRNA and protein between the exposure groups of 5 and 25 μmol/L (For 5 μmol/LF =86.355,16.404,22.898,all P ＜ 0.05;For 25 μmol/LF =104.321,20.123,52.321,all P ＜ 0.05).The expressions of miR-191 in all exposure groups of 5 and 25 μmol/L (1.392 ± 0.152,1.691 ± 0.167,2.018 ± 0.130 and 1.456 ± 0.167,1.946 ± 0.178,2.259 ± 0.256) were higher than those of control groups (1.001 ± 0.014,1.008 ±0.027,all P ＜ 0.05);the mRNA expressions of TIMP-3 in 48 h exposure group of 5 μmol/L and all exposure groups of 25 μmol/L (0.824 ± 0.093 and 0.897 ± 0.033,0.815 ± 0.089,0.709 ± 0.103) were lower than those of control groups (1.004 ± 0.018,0.997 ± 0.057,all P ＜ 0.05),but there were no significant differences in the mRNA expressions of TIMP-3 between the 12,24 h exposure groups of 5 μmol/L and control group (0.952 ± 0.072,0.929 ± 0.121 vs1.004 ± 0.018,all P ＞ 0.05);the protein expressions of TIMP-3 in all exposure groups of 5 and 25 μmol/L (0.857 ±0.068,0.832 ± 0.106,0.691 ± 0.112 and 0.785 ± 0.097,0.620 ± 0.066,0.453 ± 0.075) were lower than those of control groups (1.006 ± 0.045,1.004 ± 0.078,all P ＜ 0.05).The treatment of miR-191 inhibitorthere were significant differences in the expressions of miR-191 and TIMP-3 protein between different groups (F =104.306,67.015,all P ＜ 0.05).The elevated expression level of miR-191 induced by NaAsO2 was significantly suppressed after transfected with miR-191 inhibitor (0.314 ± 0.094 vs 2.051 ± 0.371,P ＜ 0.05),which in turn up-regulated the protein expression of TIMP-3 (1.965 ± 0.277 vs 0.541 ± 0.183,P ＜ 0.05).Conclusion The expression level of miR-191 is elevated in response to NaAsO2 exposure,and miR-191 has subsequently suppressed the expression of TIMP-3,a potential target of miR-191.