Effects of integrin α5β1 on the proliferation and migration of human aortic vascular smooth muscle cells

Integrin (ITG) alpha 5 beta 1 is a dominant fibronectin receptor that is abundantly expressed on the surface of vascular smooth muscle cells (VSMCs). However, the association between integrin alpha 5 beta 1 and the proliferation and migration of VSMCs has yet to be elucidated. The aim of the present study was to characterize the roles of ITG alpha 5 and ITG beta 1 in the proliferation and migration of VSMCs, and to determine the effects of ITG alpha 5 beta 1 on integrin-linked kinase (ILK) and focal adhesion kinase (FAK) mRNA expression. Lentiviral expression vectors as well as RNA interference vectors of ITG alpha 5 and ITG beta 1 were successfully constructed and transfected into VSMCs to obtain ITG alpha 5- and ITG beta 1-overexpressing or -silenced cells, respectively. Cell cycle distribution, proliferation and migration were analyzed in the transfected VSMCs in order to clarify the roles of ITG beta 1 and ITGa5 in the proliferation and migration of VSMCs. ITG beta 1 was markedly associated with the proliferation and migration of VSMCs, and FAK was shown to be involved in the signaling pathways of ITG beta 1. ITG alpha 5 did not exert any effects on VSMCs. The results of the present study may provide a possible therapeutic target for the prevention and treatment of early vascular disease associated with VSMCs.