Beta 1 integrins in epithelial tissues: a unique distribution in the lens.
Beta 1 integrins in epithelial tissues: a unique distribution in the lens.
复制标题
上皮组织中的 Beta 1 整合素：晶状体中的独特分布。
DOI：
10.1006/excr.1995.1186
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发表时间：
1995
影响因子：
3.7
通讯作者：
Philip,NJ
中科院分区：
文献类型：
--
作者：
Menko,AS;Philip,NJ
整合素已被证明在指导和维持细胞分化和极化中起作用。胚胎透镜提供了一个很好的系统，在其中检查它们在上皮细胞分化中的作用，因为透镜发育的所有阶段都在单个胚胎透镜中表现出来。因此，我们检测了β1整合素异二聚体在透镜上皮和分化的透镜纤维细胞中的表达和分布。在透镜上皮细胞中，β1整合素定位于所有膜表面。透镜纤维细胞沿着其侧缘以及在其与透镜囊的附着位点和在其与透镜上皮细胞的界面处含有β1整合素。β1整联蛋白在透镜中的分布与在单纯上皮、视网膜色素上皮（RPE）、肾脏和肠中观察到的分布不同，后者仅限于基底外侧定位。我们通过Western blot分析β1免疫沉淀后整合素α亚基在透镜中表达的特异性β1整合素异二聚体，并将其与RPE细胞中表达的异二聚体进行比较。在透镜中，我们检测到α 3和α 6亚基，但未检测到α1、α5和αV亚基。将透镜分为上皮细胞和纤维细胞，发现α 3在上皮细胞中表达较高，而α 6主要与纤维细胞相关。在RPE中，检测到的主要β1整联蛋白为α3。与透镜和肾脏不同，α6β 1整合素在RPE细胞中仅以低水平表达，α V也在RPE细胞中表达，但不以β 1异二聚体形式表达。与透镜一样，RPE中既未检测到α5β 1整合素，也未检测到α1β 1整合素。透镜和RPE细胞均表达β 1整合素异源二聚体的特定亚群，其可能对其分化表型的启动和维持很重要。
Integrins have been shown to play a role in directing and maintaining cell differentiation and polarization. The embryonic lens provides a good system in which to examine their role in epithelial cell differentiation, because all stages of lens development are represented in an individual embryonic lens. Therefore, we examined the expression and distribution of β1 integrin heterodimers in both the lens epithelium and the differentiated lens fiber cells. In lens epithelial cells β1 integrin was found to be localized to all membrane surfaces. Lens fiber cells contained β1 integrin all along their lateral borders as well as at the site of their attachment to the lens capsule and at their interface with lens epithelial cells. The distribution of β1 integrin in the lens was distinct from that observed in simple epithelia, the retinal pigment epithelium (RPE), kidney, and intestine, where it was limited to a basal lateral localization. We examined the specific β1 integrin heterodimers expressed in the lens by Western blot analysis for the integrin α subunits following β1 immunoprecipitation and compared them with those expressed in RPE cells. In the lens we detected α3and α6subunits but not α1, α5, or αV. When the lens was separated into epithelial and fiber cells, we found that α3was expressed at a higher level in the epithelial cells, while α6was primarily associated with the fiber cells. In the RPE the primary β1 integrin detected was α3. Unlike in lens and kidney, α6β1integrin in RPE cells was expressed only at a low level, αVwas also expressed in RPE cells but not as a β1heterodimer. As in the lens, neither α5β1nor α1β1integrin was detected in RPE. Both lens and RPE cells express a specific subset of β1integrin heterodimers which are likely to be important to the initiation and maintenance of their differentiated phenotype.