β1 Integrins Participate in the Hypertrophic Response of Rat Ventricular Myocytes

Abstract—Multiple signaling pathways have been implicated in the hypertrophic response of ventricular myocytes, yet the importance of cell-matrix interactions has not been extensively examined. Integrins are cell-surface molecules that link the extracellular matrix to the cellular cytoskeleton. They can function as cell signaling molecules and transducers of mechanical information in noncardiac cells. Given these properties and their abundance in cardiac cells, we evaluated the hypothesis that β1 integrin function is involved in the α1-adrenergic mediated hypertrophic response of neonatal rat ventricular myocytes. The hypertrophic response of this model required interaction with extracellular matrix proteins. Specificity of these results was confirmed by demonstrating that ventricular myocytes plated onto an anti–β1 integrin antibody supported the hypertrophic gene response. Adenovirus-mediated overexpression of β1 integrin augmented the myocyte hypertrophic response when assessed by protein synthesis and...