Identification of early response genes to low-intensity pulsed ultrasound in bone marrow stromal cells

Low-intensity pulsed ultrasound (LIPUS) has been applied as a therapeutic adjunct to promote fracture healing. However, the detailed molecular mechanisms by which LIPUS promotes bone fracture healing have not yet been fully elucidated. In the present study, the early response genes elicited by low-intensity pulsed ultrasound (LIPUS) in bone marrow stromal cells (BMSCs) were investigated using GeneChip® oligonucleotide microarrays. Mouse ST2 bone marrow stromal cells were used. The cells were cultured in RPMI 1640 medium supplemented with 10% fetal bovine serum at 37°C in humidified air with 5% CO2. The cells treated with LIPUS (25 mW/cm2 for 20 min), then cultured at 37°C for 0.5, 1 and 3 h. Total RNA samples were prepared from the cells, and quality of the RNA was analyzed using a Bioanalyzer 2100. Gene expression was analyzed by an Affymetrix GeneChip® system with a GeneChip Mouse Genome 430 2.0 array. Sample preparation for array hybridization was carried out as described in the manufacturer’s instructions.