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Communication between integrin receptors facilitates epicardial cell adhesion and matrix organization
Author(s) -
Dettman Robert Warren
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.585.5
Subject(s) - vitronectin , integrin , fibronectin , microbiology and biotechnology , focal adhesion , cell adhesion molecule , cell adhesion , adhesion , extracellular matrix , biology , receptor , chemistry , cell , signal transduction , biochemistry , organic chemistry
During heart development, formation of the superficial epicardium requires α 4 β 1 integrin, a receptor for fibronectin (FN) and vascular cell adhesion molecule (VCAM‐ 1). Here we investigated the role of RGD binding integrins during chick epicardial development. We detected transcripts for α 5 , α 8 , α v , β 1 , β 3 , and β 5 integrins in the proepicardial organ (PE). α 5 β 1 was organized into focal complexes and fibrillar adhesions. α v β 3 integrin was localized in focal complexes and α 8 β 1 was organized along actin filaments. Migration of EMCs in vitro was reduced by RGD‐containing peptides. We used adenoviruses expressing an antisense to chick α 4 ( AdGFPα4AS ), full‐length human ( Adhα4V5 ) or C‐terminal deleted α 4 ( Adha4ΔCV5 ) to test if α 4 regulates expression or function of RGD‐binding integrins. Expression and localization of α 5 , α 8 , and α v integrins was unchanged after AdGFPα4AS infection. However, these cells were less able to adhere to vitronectin and FN 120 . α 5 was expressed in EMCs infected with all three viruses; however in Adhα4ΔCV5 infected cells α 5 was diminished in fibrillar adhesions and new FN matrix assembly was abnormal. We propose that cooperation between α 4 β 1 and RGD integrins in the PE and epicardium is important for EMC adhesion and subepicardial matrix formation.