热休克蛋白70在妊娠早期小鼠子宫中的表达及雌激素的诱导作用

Expression of HSP70 in early pregnant mouse uteri and effect of estrogen on its synthesis

采用Western印迹、免疫组织化学、免疫电镜和图像分析技术研究了妊娠早期小鼠子宫热休克蛋白 70(Heatshockprotein ,HSP70 )的表达变化以及雌二醇对子宫HSP70表达的影响。结果表明 :( 1)与正常小鼠相比 ,孕鼠HSP70含量显著增多 ,且随妊娠日龄的增加而增加 (P <0 0 1) ;( 2 )小剂量 ( 0 2 8μg/g体重 )和大剂量 ( 1 10 μg/g体重 )雌二醇均可诱导小鼠子宫HSP70免疫反应阳性细胞数显著增加 (P <0 0 1) ,但不表现剂量依赖关系 ;( 3)Western印迹显示雌二醇使子宫HSP70蛋白谱带发生改变 ,正常小鼠仅有 73kD 1条蛋白带 ,小剂量组检出 6 8kD、 72kD、 73kD 3条蛋白带 ,大剂量组检出 72kD、 73kD 2条蛋白带 ;( 4)电镜下 ,HSP70免疫阳性反应定位于子宫内膜基质细胞胞浆与细胞核。这些结果提示 ,HSP70可能与蜕膜反应中基质细胞增殖密切相关 ,雌二醇对子宫HSP70的表达具有明显的诱导作用.

In order to investigate the expression, function and endocrine regulatory mechanism of heat shock protein 70 (HSP70) in early pregnant (D1-D6) mouse uteri, changes in immunoreactive positive cell count, content and protein bands of HSP70 and the ultrastructure localiztion of HSP70 in uteri stroma cells under different doses of dihydroxyestrin, were studied using immunohistochemistry, Western blotting, immuno-electron microscopy and image analysis techniques. The results indicate that: (1) positive HSP70 immunoreaction was localized in mouse uterine stroma and decidual cells. (2) HSP70 content increased markedly in pregnant mice and with the progress of gestation, increasing gradually from D1 to D5, peaking at D5 then decreasing from D6;(3) both small (0.28 μg/g weight) and large doses (1.10 μg/g weight) of dihydroxyestrin injected over three days can induce a marked increase in the HSP70 immunoreaction positive stroma cell count in mouse uteri (P<0.01, Control: 52.86±6.19/eyeshot, 1.10 μg/g weight: 161.28±13.95/eyeshot);Western blotting analysis showed that dihydroxyestrin also caused distinct changes in HSP70 protein bands; there was just one 73 kD protein band in the control group, three protein bands (68 kD, 72 kD and 73 kD) in the small dose group, and two protein bands (72 kD and 73 kD) in the large dose group (P<0.01); (4)electron microscopy revealed that positive HSP70 immunoreaction was localized in the cytoplasmic matrix and nucleolus of endometrial stroma cells; aurosol granules were localized outside and inside the karyotheca of the same stroma cells and accumulated in a certain region of nucleolus. These results suggest that there is a significant relationship between HSP70 and the proliferation of uterine stroma cell during decidualization, and that dihydroxyestrin has a significant effect on the expression of HSP70 in mouse uteri that is not dosage-dependent. One possible mechanism for this effect is that dihydroxyestrin influences the proliferation of uterine stroma cells by stimulating the synthesis of HSP70. There is possibly positive feedback between the regulation of dihydroxyestrin in the endometrium and the expression of HSP70 .