ABSTRACT
Objective To investigate the effect of cyclic stretch on Src and Runt-related transcription factor 2 (RUNX2), and their pivotal roles in migration of vascular smooth muscle cells (VSMCs). Methods The 5% cyclic stretch (to simulate normotensive physiological condition) or 15% cyclic stretch (to simulate hypertensive pathological condition) was applied to VSMCs by FX-5000T system. Western blotting was used to detect the expression of RUNX2 and phosphorylation of Src in VSMCs. The Ingenuity Pathway Analysis (IPA) bioinformatic software was used to analyze the potential regulatory effect of Src on RUNX2. Small interfering RNA (siRNA) was transfected to decrease the expression of RUNX2. Src inhibitor-1 was used to repress Src kinase activity; Wound-healing assay was applied to detect VSMC migration. Results Compared with 5% cyclic stretch, 15% cyclic stretch significantly increased RUNX2 expression in VSMCs. Under both static and 15% cyclic stretch conditions, VSMC migration was significantly inhibited after reducing RUNX2 expression with siRNA transfection. IPA indicated that Src kinase might be the upstream modulator of RUNX2, and Western blotting validated that RUNX2 expression was significantly decreased after inhibiting Src. Furthermore, under 15% cyclic stretch, Src inhibitor-1 markedly repressed RUNX2 expression and VSMC migration.Conclusions High cyclic stretch increased phosphorylation of Src kinase and expression of RUNX2, which subsequently induced VSMC abnormal migration. Exploring the mechanobiological mechanism of VSMC migration regulated by cyclic stretch may contribute to further revealing the mechanism of vascular physiological homeostasis and vascular pathological remodeling, as well as providing new perspective for the translational research of vascular remodeling upon hypertension.