苯并(a)芘、预热及其联合作用对人胚肺细胞HSP70合成的影响

Combined Effects of Pre-heated Treatment and Benzo(a)pyrene on HSP70 Synthesis in HEL Cells

用 Western blot方法探讨苯并 (a)芘、预热及其联合作用对人胚肺 (HEL)二倍体细胞热应激蛋白 70(HSP70 )合成的影响。结果表明未经 S9活化的 HEL 细胞 ,在不同剂量的 Ba P处理后 ,可轻度诱导 HSP70的表达 ;经 S9活化的 Ba P作用 HEL 细胞 3h,HSP70表达抑制 ,呈剂量 -反应关系 ,在较高浓度染毒时抑制作用表现明显 (P<0 .0 5 ) ;预热应激的 HEL 细胞 HSP70表达增加 ,但 Ba P染毒 3h后 HSP70表达并不规律 ,具体表现为低剂量 (10～ 5 0 ) μmol/ L诱导 ,而高剂量 (5 0～ 2 0 0 ) μmol/ L 呈抑制趋势。结果提示 ,体外未经代谢活化的 Ba P可以作为应激原诱导热休克反应 ;HSP70表达降低可能是 Ba P代谢活化产物作用的结果 ,预热诱导 HSP70表达增加很可能掩盖了低浓度时 Ba P对

The combined effects of benzo(a)pyrene and preheated treatment on HSP70 synthesis in human embryonic lung cells (HELs) were studied. The cultured HEL cells were divided into the following three groups: BaP group (only treated with BaP at the final concentrations of 0, 10, 50, 100, 200μmol/L), BaP+S9 mix (in the presence of S9 mix, stimulated by the same final concentrations as those of BaP group) and preheated one ( heat treated at 41℃ for 1 h, recovered at 37℃ for 2 h and stimulated by the same dose of BaP as the mentioned above). The incubation time was 3 h respectively. 0 μmol/L BaP mentioned above served as the vehicle control. The levels of HSP70 expression were determined by Western blotting. The results showed that the level of HSP70 was increased in different concentrations of BaP treated HEL cells (in the absence of S9 mix). The effects of BaP on HSP70 synthesis in BaP+S9 mix group were repressed in a dose dependent manner, and significant difference from the 0μmol/L was observed at the dose of 200 μmol/L BaP. However, combined effects of BaP and preheated treatment (in the presence of S9 mix) on HSP70 synthesis showed no evident rules, and the levels of HSP70 were enhanced after preheated treatment. These results indicated that BaP could be acted as a stressor to induce the heat stress response and inhibit the expression of HSP70 in the presence of S9 mix, which might be due to the metabolites of BaP.