Regulation of cytokeratin expression in rat lung alveolar epithelial cells in vitro.
Regulation of cytokeratin expression in rat lung alveolar epithelial cells in vitro.
复制标题
体外大鼠肺泡上皮细胞细胞角蛋白表达的调节。
DOI：
10.1152/ajplung.1995.269.4.l536
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Wilcoxen,SE
中科院分区：
文献类型：
--
作者：
Paine,R;Gaposchkin,D;Kelly,C;Wilcoxen,SE
II型肺细胞是肺泡上皮的干细胞，在肺生长期间或损伤后增殖并分化成I型细胞。体外II型细胞的细胞角蛋白表达模式与这些细胞的分化状态有关。特别是，细胞角蛋白19的表达与II型细胞表型相关。我们现在研究的作用，细胞形状和细胞间的相互作用，在调节细胞角蛋白的表达大鼠II型细胞在体外。通过以高或低密度（3.5或0.5 × 10（5）个细胞/cm 2）接种培养物调节II型细胞扩散和细胞间接触。当在高密度下培养时，与在低密度下高度铺展的细胞相比，细胞表现出增加的细胞角蛋白19蛋白合成和减少的细胞角蛋白18蛋白合成。这种效应反映了单个细胞角蛋白mRNA丰度的变化。高密度的肺泡上皮细胞也在细胞间形成广泛的桥粒。当细胞以低密度或在减少的（0.05 mM）钙培养基中接种时，桥粒形成显著降低。细胞角蛋白19的mRNA和蛋白质表达也显着下降时，桥粒的形成受到抑制，在减少钙介质，而钙含量的介质上的细胞角蛋白18的影响不大。这些研究表明，细胞角蛋白19，分化相关的细胞角蛋白，II型细胞的表达受到影响细胞形状和上皮细胞之间的细胞间接触的因素。他们进一步表明，上皮细胞之间的细胞-细胞相互作用可能在上皮细胞表型的调节中发挥作用。
Type II pneumocytes are the stem cells for the alveolar epithelium, proliferating and differentiating into type I cells during lung growth or after injury. The pattern of cytokeratin expression by type II cells in vitro has been linked to the state of differentiation of these cells. In particular, cytokeratin 19 expression has been associated with the type II cell phenotype. We now examine the roles of cell shape and cell-cell interactions in the regulation of cytokeratin expression by rat type II cells in vitro. Type II cell spreading and intercellular contacts were modulated by seeding cultures at high or low density (3.5 or 0.5 x 10(5) cells/cm2). When cultured at high density, cells demonstrated increased cytokeratin 19 protein synthesis and diminished cytokeratin 18 protein synthesis compared with highly spread cells at low density. This effect was a reflection of changes in the abundance of mRNAs for the individual cytokeratins. Alveolar epithelial cells at high density also formed extensive desmosomes between the cells. Desmosome formation was significantly decreased when cells were seeded at low density or in reduced (0.05 mM) calcium medium. Cytokeratin 19 mRNA and protein expression were also significantly decreased when desmosome formation was inhibited in reduced calcium medium, while calcium content of the medium had little effect on cytokeratin 18. These studies suggest that type II cell expression of cytokeratin 19, a differentiation-related cytokeratin, is regulated by factors influencing cell shape and intercellular contacts between epithelial cells. They further suggest that cell-cell interactions between epithelial cells may play a role in the modulation of epithelial cell phenotype.