ABSTRACT
OBJECTIVE To investigate the effect of mono-2-ethylhexyl phthalate(MEHP) on proliferation of primary neural stem cells(NSCs)of rats and NE-4C cells of mice and on the migration of NE-4C cells and the mechanism. METHODS NE-4C or NSCs were treated with MEHP 1,10,100 and 1000 μmol · L-1 for 72 h,respectively. The cytotoxicity was estimated with the cell counting kit-8 (CCK-8). Cell proliferation was analyzed by EdU assay. The mRNA expression levels of the glucocorticoid receptor(GR),signal transducer and activator of transcription 3(Stat3)and sex determining region Y (SRY)-box 2(Sox2) were detected by qRT-PCR. The protein expression levels of total GR,GRβ, Sox2,Stat3 and p-Stat3 were measured by Western blotting. RESULTS Cell viability of NE-4C cells and NSCs at MEHP 1000μmol·L-1 was significantly decreased,which was 70.3%and 40.0%of the control group, respectively. EdU assay showed that MEHP 100 μmol · L-1 decreased NE-4C cells and NSCs by 74.8%and 12.0%(P<0.05)compared with control. The effect of MEHP on the cell migration of NE-4C was evidenced by the fact that the migration was obviously reduced to (63.4±2.0)%(P<0.05)after treatment with MEHP 100μmol · L-1 for 72 h. The mRNA expression levels associated with proliferation and migration in NE-4C of GR,Stat3 and Sox2 in MEHP 100 μmol · L-1 group were down-regulated to 49.8%,26.0% and 14.0%of control(P<0.05). At MEHP 100μmol · L-1,mRNA of GR, Stat3 and Sox2 in NSCs declined to 10.0%,14.0% and 15.3% of normal control. Western blotting results revealed that protein expressions of GR,GRβ,Sox2 and p-Stat3 were remarkably inhibited by MEHP 100 μmol · L-1 in that the relative expression of NE-4C was 0.92 ± 0.17,0.87 ± 0.35,0.81 ± 0.22 and 0.62 ± 0.24(P<0.05). The corresponding protein expression in NSCs was 0.82 ± 0.20,0.56 ± 0.12,0.84 ± 0.36 and 0.53 ± 0.20(P<0.05)when the cells were treated with MEHP 100μmol · L-1 for 72 h. CONCLUSION MEHP can inhibit the proliferation and migration of NE-4C cells and NSCs possibly by decreasing Stat3 and Sox2 that are mediated by GRβ.