The influence of Berzo[a] pyrene on the damage of primary cultured rat nerve cells and Hsp70 expression

Objective To study the effect of benzo[a]pyrene(B[a]P) on damage and Heat shock protein 70(Hsp70) expression in primary culture nerve cells from rats.Methods Cortical nerve cells of SD rats(aged within 3 days) were isolated and cultured,which were exposed by different doses of B[a]P and S9.The morphological changes of nerve cells were observed by invert microscope.MTT assay was used to detect cell viability.The LDH activity and MDA concentration were detected by ultraviolet spectrophotometer.The cell apoptosis rate was detected by flow cytometry.DNA damage was detected by single cell gel electrophoresis.The expression of Hsp70 was measured by Western blot.Results After 24 h exposed by B[a]P+S9,the numbers of axons and dendrites of nerve cells were decreased,the length of synapses was shortened,some cells became vacuolated and the cell viability decreased.The LDH activity,MDA concentration in cell culture medium,Olive tail and apoptosis rate of nerve cell increased with doses of B[a]P,and there were significant differences among 0.5~10 μmol/L groups and control group.The expression of Hsp70 in 0.5~10 μmol/L groups decreased and the difference was significant(P0.05) compared with 0.1 μmol/L group,and it was lower in 10 μmol/L group than control group(P0.05).Simple correlation analysis indicated that there had a positive correlation between MDA,LDH,Olive tail,and cell apoptosis rate,while a negative correlation between MDA,Hsp70,and cell viability(A value).The Hsp70 had a negative correlation with LDH,Olive tail and cell apoptosis rate,while a positive correlation with cell viability(A value).A similar positive correlation existed between LDH,Olive tail and cell apoptosis rate.Conclusion B[a]P metabolites could lead to the injury and apoptosis of primary culture of nerve cells from rats and inhibited the expression of Hsp70,which might relate to B[a]P neurotoxicity.