ABSTRACT
This article review summarizes data on cell-substratum adhesion complexes involved in the regulation of cellular functions in the intestine. We first focus on the molecular composition of the two main adhesion structures-the beta1 integrin-adhesion complex and the hemidesmosome-found in vivo and in two human intestinal cell lines. We also report the key findings on the cellular behavior and response to the extracellular matrix that involve integrins, the main transmembrane anchors of these complexes. How the dynamics of cell/extracellular matrix interactions contribute to cell migration, proliferation, differentiation, and tumorigenicity is discussed in the light of the data provided by the human intestinal cells.
Subject(s)
Extracellular Matrix/metabolism , Integrin beta1/metabolism , Intestinal Mucosa/metabolism , Caco-2 Cells , Cell Adhesion , Cell Differentiation , Cell Division , Cell Movement , Cell Transformation, Neoplastic , HT29 Cells , Hemidesmosomes/metabolism , Humans , Integrin beta1/analysis , Integrins/analysis , Integrins/metabolism , Microscopy, ConfocalABSTRACT
In this study we investigated the cellular distribution of talin, a cytoskeletal protein, during mammalian cell cytokinesis. Immunohistochemical experiments on various carcinoma cell lines and mesenchyme-derived cells reveal that talin displays a cell cycle-dependent cellular localization. During metaphase, talin is located in the centromeric region of the chromosome, like the TD-60 protein and intrinsic centromere components detected by a CREST serum. From anaphase to telophase, talin is present in the cleavage furrow. As the cells progress to cytokinesis, when the furrow is complete, talin is concentrated in the midbody structures, as assessed by immunofluorescence and confirmed by Western blot experiments on purified midbodies. Double staining experiments reveal that alpha-tubulin, TD-60 protein, and talin co-localize in the midbodies. These results suggest that talin, in addition to its implication in focal adhesion organization and signaling, may play a critical role in cytokinesis. (J Histochem Cytochem 47:1357-1367, 1999)
Subject(s)
Cell Cycle/physiology , Talin/physiology , Adenocarcinoma , Animals , Cell Division , Cell Line , Centromere/physiology , Centromere/ultrastructure , Chromosomes, Human/physiology , Chromosomes, Human/ultrastructure , Colonic Neoplasms , Humans , Intestinal Mucosa/cytology , Intestinal Mucosa/physiology , Mammals , Metaphase , Rats , Talin/analysis , Tumor Cells, CulturedABSTRACT
Dynamic and reciprocal heterotypic cell interactions are crucial for intestinal morphogenesis and differentiation. This paper emphasizes the role of basement membrane molecules and in particular of laminins as potent mediators in this intercellular cross talk. Changes in the expression or localization of laminin isoforms or of integrins during development and cell migration strengthen the concept that heterogeneity in cell-matrix interactions could mediate distinct cell responses. A combination of genetic or biochemical approaches associated with in vitro models allows us to study the potential role of each laminin isoform in basement membrane assembly, cell migration, or cell differentiation.