Expression of Focal Adhesion Proteins in the Developing Rat Kidney

• Published in: The journal of histochemistry and cytochemistry 2011-09, Vol.59 (9), p.864-874
• Main Authors: Matsuura, Sato, Kondo, Shuji, Suga, Kenichi, Kinoshita, Yukiko, Urushihara, Maki, Kagami, Shoji
• Format: Article
• Language: English
• Subjects: Animals; Blotting, Western; Cytoskeletal Proteins - analysis; Cytoskeletal Proteins - biosynthesis; Cytoskeletal Proteins - immunology; DNA-Binding Proteins - analysis; DNA-Binding Proteins - biosynthesis; DNA-Binding Proteins - immunology; Focal Adhesion Protein-Tyrosine Kinases - analysis; Focal Adhesion Protein-Tyrosine Kinases - biosynthesis; Focal Adhesion Protein-Tyrosine Kinases - immunology; Focal Adhesions - enzymology; Focal Adhesions - metabolism; Gene Expression Profiling; Gene Expression Regulation, Developmental; Immunohistochemistry; Kidney - embryology; Kidney - growth & development; Kidney - immunology; Kidney - metabolism; LIM Domain Proteins; Paxillin - analysis; Paxillin - biosynthesis; Paxillin - immunology; Protein-Serine-Threonine Kinases - analysis; Protein-Serine-Threonine Kinases - biosynthesis; Protein-Serine-Threonine Kinases - immunology; Rats; Rats, Sprague-Dawley
• ISSN: 0022-1554; 1551-5044
• DOI: 10.1369/0022155411413929

Focal adhesions play a critical role as centers that transduce signals by cell-matrix interactions and regulate fundamental processes such as proliferation, migration, and differentiation. Focal adhesion kinase (FAK), paxillin, integrin-linked kinase (ILK), and hydrogen peroxide–inducible clone-5 (Hic-5) are major proteins that contribute to these events. In this study, we investigated the expression of focal adhesion proteins in the developing rat kidney. Western blotting analysis revealed that the protein levels of FAK, p-FAK397, paxillin, p-paxillin118, and Hic-5 were high in embryonic kidneys, while ILK expression persisted from the embryonic to the mature stage. Immunohistochemistry revealed that FAK, p-FAK397, paxillin, and p-paxillin118 were strongly expressed in condensed mesenchymal cells and the ureteric bud. They were detected in elongating tubules and immature glomerular cells in the nephrogenic zone. Hic-5 was predominantly expressed in mesenchymal cells as well as immature glomerular endothelial and mesangial cells, suggesting that Hic-5 might be involved in mesenchymal cell development. ILK expression was similar to that of FAK in the developmental stages. Interestingly, ILK was strongly expressed in podocytes in mature glomeruli. ILK might play a role in epithelial cell differentiation as well as kidney growth and morphogenesis. In conclusion, the temporospatially regulated expression of focal adhesion proteins during kidney development might play a role in morphogenesis and cell differentiation.