Calcium-induced intercellular adhesion of keratinocytes does not involve accumulation of β1 integrins at cell-cell contacts and does not involve changes in the levels or phosphorylation of catenins
Calcium-induced intercellular adhesion of keratinocytes does not involve accumulation of β1 integrins at cell-cell contacts and does not involve changes in the levels or phosphorylation of catenins
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DOI：
10.3109/15419069809040287
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发表时间：
1998-01-01
期刊：
影响因子：
--
通讯作者：
Watt, FM
中科院分区：
文献类型：
--
作者：
Braga, VMM;Hajbagheri, N;Watt, FM
在终末分化开始时，人表皮角质形成细胞由于失活和随后细胞表面整合素的丢失而从下层基膜分离。角质形成细胞组装成多层片需要功能性E-和p -钙粘蛋白，当分层在低钙培养基中被抑制时，分化的角质形成细胞继续表达功能性整合素。使用免疫荧光显微镜，我们发现，在角质形成细胞单层中添加钙离子时，除了靠近基质的区域外，β(1)整合素和E-钙粘蛋白沿着外侧膜共定位，只有下层含有整合素。定量免疫电镜显示，在诱导细胞-细胞稳定接触时，β(1)整合素在顶膜和侧膜上的密度相同，说明免疫荧光显微镜观察到的侧膜上整合素的积累是由于相邻细胞之间接触面积的增加，而不是受体密度的增加。诱导细胞-细胞接触后，连环蛋白的水平和磷酸化程度没有变化。这些观察结果为角化细胞钙依赖性细胞间粘附的机制提供了新的视角。
On initiation of terminal differentiation human epidermal keratinocytes detach from the underlying basement membrane as a result of inactivation and subsequent loss of integrins from the cell surface. Assembly of keratinocytes into multilayered sheets requires functional E- and P-cadherin and when stratification is inhibited in low calcium medium differentiating keratinocytes continue to express functional integrins, Using immunofluorescence microscopy, we found that on addition of calcium ions to keratinocyte monolayers there was colocalisation of the beta(1) integrins and E-cadherin along the lateral membranes except for a zone close to the substratum which exclusively contained integrins, Quantitative immunoelectron microscopy showed that on induction of stable cell-cell contacts the density of beta(1) integrins was the same on the apical and lateral membranes, suggesting that the accumulation of integrins on the lateral membranes observed by immunofluorescence microscopy is due to the increased area of contact between adjacent cells and not to an increase in receptor density. There were no changes in the levels of catenins and their degree of phosphorylation after induction of cell-cell contacts. These observations provide new sights into the mechanism of calcium-dependent intercellular adhesion of keratinocytes.