Communication between integrin receptors facilitates epicardial cell adhesion and matrix organization.
Formation of the epicardium requires interactions between alpha(4)beta(1) integrin, and the extracellular matrix. We investigated the role of other integrins expressed by epicardial cells. We detected transcripts for alpha(5), alpha(8), alpha(v), beta(1), beta(3), and beta(5) integrins in the chick proepicardial organ (PE). We demonstrate that alpha(5)beta(1), alpha(8)beta(1), and alpha(v)beta(3) integrins are expressed by chick epicardial mesothelial cells (EMCs). Migration of EMCs in vitro was reduced by RGD-containing peptides. Using adenoviruses expressing an antisense to chick alpha(4) (AdGFPalpha4AS), full-length (Adhalpha4V5), and C-terminal deleted alpha(4) (Adhalpha4DeltaCV5), we found that EMCs were less able to adhere to vitronectin and fibronectin(120) indicating that alpha(4)beta(1) plays a role in regulating EMC adhesion to ligands of alpha(5)beta(1), alpha(8)beta(1), and alpha(v)beta(3). In Adhalpha4DeltaCV5-infected EMCs, alpha(5)beta(1) was diminished in fibrillar adhesions and new FN matrix assembly was abnormal. We propose that cooperation between alpha(4)beta(1) and RGD integrins is important for EMC adhesion and subepicardial matrix formation.
Pae
So Hyun
SH
Northwestern University, Feinberg School of Medicine, Department of Pediatrics, Neonatology Research Laboratory, Chicago, Illinois, USA.
Dokic
Danijela
D
Dettman
Robert W
RW
D000818:Animals; D002448:Cell Adhesion / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology; D002642:Chick Embryo / Q000033:anatomy & histology / Q000378:metabolism; D003331:Coronary Vessels / Q000033:anatomy & histology; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism; D004848:Epithelium / Q000033:anatomy & histology / Q000378:metabolism; D005109:Extracellular Matrix / Q000737:chemistry / Q000378:metabolism*; D005353:Fibronectins / Q000378:metabolism; D006801:Humans; D039041:Integrin alpha4beta1 / Q000235:genetics / Q000378:metabolism*; D039081:Integrin alpha5beta1 / Q000235:genetics / Q000378:metabolism*; D009842:Oligopeptides / Q000378:metabolism; D010496:Pericardium / Q000166:cytology* / Q000196:embryology* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D019096:Vitronectin / Q000378:metabolism
D005353:Fibronectins; D039041:Integrin alpha4beta1; D039081:Integrin alpha5beta1; D009842:Oligopeptides; D011993:Recombinant Fusion Proteins; D019096:Vitronectin; C047981:arginyl-glycyl-aspartic acid