Modulation of the epithelial barrier by dexamethasone and prolactin in cultured Madin-Darby canine kidney (MDCK) cells
Modulation of the epithelial barrier by dexamethasone and prolactin in cultured Madin-Darby canine kidney (MDCK) cells
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DOI：
10.1016/j.cellbi.2005.08.004
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发表时间：
2006-02-01
影响因子：
3.9
通讯作者：
Collares-Buzato, CB
中科院分区：
文献类型：
--
作者：
Peixoto, EBMI;Collares-Buzato, CB
糖皮质激素和催乳素（PRL）对培养的内皮细胞和乳腺上皮细胞紧密连接（TJ）的形成和维持有直接影响。在这项工作中，我们研究了合成的糖皮质激素地塞米松（DEX）和PRL对MDCK肾上皮细胞的细胞旁屏障功能的影响。DEX（4 μ M）+ PRL（2 μ g/ml）和DEX单独使用可显著增加汇合MDCK单层慢性处理（4天）或亚汇合单层处理24小时后的跨上皮电阻。免疫印迹和免疫细胞化学显示，TJ相关蛋白occludin，ZO-1和claudin-1的表达和分布在融合单层激素添加后没有变化。然而，在接触DEX或DEX + PRL 24 h的近汇合MDCK单层细胞中观察到occludin和ZO-1的连接含量显着增加，而其总表达无变化。激素处理后，在亚融合条件下未检测到细胞增殖/生长的变化。暴露于DEX + PRL后，仅在融合MDCK单层中观察到活细胞总数增加，表明这些激素对已建立屏障的主要作用可能与抑制细胞死亡相关。总之，我们的数据表明，这些激素（特别是地塞米松）对TJ的结构和功能的影响，只有在MDCK上皮屏障的形成，可能通过调节TJ蛋白的定位，稳定性或组装到细胞间接触的膜网站。(c)2005年国际细胞生物学联合会。由爱思唯尔有限公司出版。保留所有权利。
Glucocorticoids and prolactin (PRL) have a direct effect on the formation and maintenance of tight junctions (TJs) in cultured endothelial and mammary gland epithelial cells. In this work, we investigated the effect of a synthetic glucocorticoid dexamethasone (DEX) and PRL on the paracellular barrier function in MDCK renal epithelial cells. DEX (4 mu M) + PRL (2 mu g/ml) and DEX alone increased significantly the transepithelial electrical resistance after chronic treatment (4 days) of confluent MDCK monolayers or after 24 h treatment of subconfluent monolayers. Immunoblotting and immunocytochemistry revealed no changes in the expression and distribution of TJ-associated proteins occludin, ZO-1 and claudin-1 in confluent monolayers after hormone addition. However, a marked increase in junctional content for occludin and ZO-1 with no changes in their total expression was observed in subconfluent MDCK monolayers 24 h exposed to DEX or DEX + PRL. No change in cell proliferation/growth was detected at subconfluent conditions following hormone treatment. An increase in the total number of viable cells was observed only in confluent MDCK monolayers after exposure to DEX + PRL suggesting that the main effect of these hormones on already established barrier may be associated with the inhibition of cell death. In Conclusion, our data Suggest that these hormones (specially dexamethasone) have an effect on TJ structure and function only during the formation of MDCK epithelial barrier by probably modulating the localization, stability or assembly of TJ proteins to membrane sites of intercellular contact. (c) 2005 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.