Research On Cell Proliferation And Apoptosis Of Bile Salt (GCDA) Treated Hepatic Cell And Its Molecular Mechanism

ObjectiveTo study the effect and molecular mechanism of bile salt(GCDA) on hepatocyte by researching the effect of bile salt (GCDA) on the cell proliferation and apoptosis.Methods1.Trypan blue staining examined the cell viability of L02, QSG7701, HepG2after treated with GCDA.2.MTT estimated the influence of GCDA on three kind of cells:L02, QSG7701,HepG2.3.Cell morphology observation method was used to detect the changes of L02cell morphology after GCDA treatment.4.Hoechst33258method and DNA ladder method were to detect L02cell apoptosis after treated by GCDA.5.Immunofluorescence and Western blotting were used to observe the expreesion of Mcl-1and DNA damage and repair related proteins following GCDA treated L02cell..ResultsTrypan blue staining and MTT showed that, at low concentrations, GCDA(≤50μM/L) promoted cell proliferation of L02and QSG7701, while high concentrations, it(>50μM/L) inhibited cell proliferation; HepG2cells promoted cell proliferation by GCDA (0-400μM/L). After GCDA treated, cell morphology changed obviously and reduced the cell adherence, the number of alive cells was also reduced. Furthermore, L02nuclei appeared the typical morphological features of apoptosis. DNA ladder results showed slightly "trapezoid" DNA ladder of L02. Immunofluorescence staining suggested that APE-1, Mcl-1were both expressed. Western blotting revealed increasing GCDA concentration, Mcl-1was upregulated first and then downregulated. Ku70, Ku86, etc,was upregulated. With time increasing of GCDA disposed on L02, showed to reduce expression of Mcl-1and enhance the expression of Ku70, Ku86, etc.ConclusionLow concentration of GCDA could promote proliferation of normal liver cells, while high concentrations may induce apoptosis. The mechanism of apoptosis of heptocyte by GCDA is likely to be via upregulated the expression of Mcl-1and induced DNA damage, two kinds of pathways interact to regulate cell apoptosis.