Loss of gap junctions from DDT-treated rat liver epithelial cells.
Loss of gap junctions from DDT-treated rat liver epithelial cells.
复制标题
DDT 处理的大鼠肝上皮细胞间隙连接丢失。
DOI：
10.1093/carcin/15.2.301
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发表时间：
1994
期刊：
影响因子：
4.7
通讯作者：
Trosko,JE
中科院分区：
文献类型：
--
作者：
Ruch,RJ;Bonney,WJ;Sigler,K;Guan,X;Matesic,D;Schafer,LD;Dupont,E;Trosko,JE
肝脏肿瘤启动子1,1-二（对氯苯基）-2,2,2-三氯乙烷（DDT）抑制wbf344大鼠肝上皮细胞间隙连接细胞间通讯（GJIC）的机制可能涉及间隙连接丢失和/或间隙连接通道通透性降低。我们在本研究中考察了这两种可能性。使用connexin43（这些细胞表达的主要间隙连接蛋白）特异性抗体的免疫组织化学研究显示，暴露于DDT期间，间隙连接的数量和大小减少。间隙连接的减少（33-91%）与剂量依赖性（1-10 μM）和时间依赖性（0.5-4 h）细胞间荧光偶联的减少（64-85%）以及磷酸化连接蛋白的细胞水平相关。从培养基中去除肿瘤启动子后，这些影响是可逆的，尽管环己亚胺降低了间隙连接重组的水平。间隙连接的损失不是由于connexin43基因表达的减少，因为connexin43 mRNA的稳态水平不受DDT的类似影响。滴滴涕的结构类似物Fenarimol （10 μM）对GJIC没有抑制作用，对间隙连接结构和connexin43的表达没有影响。这些数据表明滴滴涕对GJIC的抑制是由于质膜间隙连接的去除及其降解，而不仅仅是其渗透性的降低。
The mechanism by which the liver tumor promoter 1,1-bis(p-pchlorophenyl)-2,2,2-trichloroethane (DDT) inhibits gap junctional intercellular communication (GJIC) in WB-F344 rat liver epithelial cells could involve gap junction loss and/or decreased gap junction channel permeability. We examined these two possibilities in the present study. Immunohistochemical studies using antibodies specific to connexin43, the major gap junction protein expressed by these cells, revealed that gap junction number and size were reduced during exposure to DDT. The reductions in gap junctions (33–91%) correlated with dose-dependent (1–10 μM) and time-dependent (0.5–4 h) decreases in cell-to-cell fluorescent dyecoupling (64–85%), as well as cellular levels of phosphorylated connexin43. These effects were reversible following removal of the tumor promoter from the culture medium, although cycloheximide reduced the level of gap junction reformation. The losses in gap junctions were not due to decreased connexin43 gene expression since steady-state levels of connexin43 mRNA were not similarly affected by DDT. Fenarimol (10 μM), a structural analog of DDT, did not inhibit GJIC and had no effect on gap junction structure or connexin43 expression. These data suggest that the inhibition of GJIC by DDT resulted from the removal of gap junctions from the plasma membrane and their degradation rather than simply a decrease in their permeability.