Effects of tumor promoters on LLC-PK1 renal epithelial tight junctions and transepithelial fluxes.
Effects of tumor promoters on LLC-PK1 renal epithelial tight junctions and transepithelial fluxes.
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肿瘤启动子对 LLC-PK1 肾上皮紧密连接和跨上皮通量的影响。
DOI：
10.1152/ajpcell.1986.251.4.c597
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
O'Brien,TG
中科院分区：
文献类型：
--
作者：
Mullin,JM;O'Brien,TG
肿瘤促进剂12-O-十四酰基佛波醇-13-乙酸酯（TPA）以剂量依赖性方式不可逆地消散LLC-PK 1肾上皮细胞片层之间的电势差（PD）。当呈递至任一细胞表面时，启动子同样有效。TPA也同样有效地消散顶端-负PD或迄今为止未描述的顶端-正PD，这两者都可以自发地存在于该单层中。TPA同样降低了由施加NaCl梯度穿过LLC-PK 1细胞片层引起的扩散电位。非肿瘤促进母体化合物佛波醇无效，但更亲水的TPA类似物佛波醇12，13-二丁酸酯（PDBU）与TPA一样有效。与TPA不同，PDBU的作用是可逆的。通过观察D-甘露醇和聚乙二醇的（细胞旁）通量，这些对PD的影响被证明是由于紧密连接的渗透性增加。一旦PDBU被去除，这种效应立即可逆。这些研究结果进行了讨论，在光的上皮细胞在体内的车厢和作用，这可能会在调节上皮细胞生长的崩溃的后果。
The tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) irreversibly dissipates the electrical potential difference (PD) across LLC-PK1 renal epithelial cell sheets in a dose-dependent manner. The promoter is equally effective when presented to either cell surface. TPA is also equally effective at dissipating the apical-negative PD or the heretofore undescribed apical-positive PD, both of which can exist spontaneously across this monolayer. Diffusion potentials arising from imposed NaCl gradients across LLC-PK1 cell sheets are likewise reduced by TPA. The non-tumor-promoting parent compound, phorbol, is ineffective, but the more hydrophilic TPA analogue, phorbol 12,13-dibutyrate (PDBU) is as effective as TPA. Unlike TPA, the effects of PDBU are reversible. By observing the (paracellular) fluxes of D-mannitol and polyethylene glycol, these effects on PD are shown to be due to increased permeability of the tight junctions. This effect is immediately reversible once PDBU is removed. These findings are discussed in light of the ramifications of the breakdown of epithelial compartments in vivo and the role this could play in the regulation of epithelial cell growth.