The pathological role of mitochondrial apoptosis pathway and related factors in fluorosis-induced apoptosis of human hepatocellular carcinoma cell strain / 中华地方病学杂志

ABSTRACT

Objective To investigate the possible pathological role of mitochondrial apoptosis pathways and its factors in fluorosis-induced apoptosis of human hepatocellular carcinoma cell strain (HepG2).Methods Under the stimulation of 1,3,6 and 9 mmol/L concentrations of NaF in vitro for 24 h (n =5),while normal control group was cultured under normal condition,the cytotoxicity was measured with MTT.The mitochondrial apoptosis inducing factor (AIF) was measured at both mRNA (n =5) and protein levels (n =6),respectively,by real-time PCR and Western blotting.The mitochondrial apoptosis related factors,such as B-cells lymphoma-2 (Bcl-2),Bcl-associated X protein (Bax),cytochrome C,caspase-9 and caspase-3 were measured at protein levels (n =6).Results After treated with 0,1,3,6 and 9 mmol/L NaF for 24 h,the cell absorbance of HepG2 cells was 0.307 ± 0.031,0.333 ± 0.028,0.230 ± 0.011,0.178 ± 0.001 and 0.152 ± 0.003,respectively,and the differences were statistically significant among groups (F =82.224,P ＜ 0.01).After treated with 3 mol/L NaF for 24 h,the mRNA level of AIF was [(153.14 ± 5.41)％] which was increased compared to the control group [(100.00 ± 4.70)％,t =-4.73,P ＜0.05].Under the same condition,the protein levels of AIF,Bcl-2,cytochrome C in cytoplasm,caspase-9 and caspase-3 were (152.16 ± 47.30)％,(171.90 ± 51.52)％,(458.00 ± 19.48)％,(527.17 ± 200.67)％ and (432.70 ±64.27)％,which were increased compared to those of the control groups [(100.00 ± 48.86)％,(100.00 ± 34.44)％,(100.00 ± 116.59)％,(100.00 ± 19.58)％ and (100.00 ± 137.16)％,t =-3.80,-3.96,-15.76,-4.64,-5.06,all P ＜ 0.05],while the protein levels of Bax and cytochrome C in mitochondrion were (24.66 ± 26.04)％,(72.99 ±45.34)％,which were decreased compared to those of the control groups [(100.00 ± 44.01)％,(100.00 ± 34.14)％,t =6.35,0.68,all P ＜ 0.05].Conclusion The mitochondrial apoptosis pathway and related factors may be involved in NaF-induced cell death in HepG2 cells.