Signal transduction pathways activated by low-intensity pulsed ultrasound. Area enclosed with a black broken line is the signaling pathway specified in the present experiment. One of the receptors of low-intensity pulsed ultrasound (LIPUS) is through integrin, and the integrin/mitogen-activated protein kinase (MAPK) pathway is activated to the same extent in both the LIPUS group and the control group. The integrin/phosphatidylinositol 3 kinase (PI3K)/Akt pathway, however, was further activated by LIPUS. The expression of β-catenin, which is downstream of the Akt signaling pathways, is also increased by LIPUS. FAK, focal adhesion kinase; GSK-3, glycogen synthase kinase-3; Pax, Paxillin.