Gene expression in response to low-intensity pulsed ultrasound treatment of bone marrow cells under osteogenic conditions in vitro

We performed a comprehensive analysis of gene expression changes following low-intensity pulsed ultrasound (LIPUS) treatment of cultured bone marrow cells under bone formation conditions, using cDNA microarray analysis Bone marrow cells were obtained from the femora of rats and were suspended in an osteogenic medium to make a cell culture. After cultures were established, test cultures were exposed to LIPUS via the base of the cell culture plates for 15 min/day on days 3–9 (LIPUS group). Control cultures (without LIPUS exposure) were otherwise treated identically to the LIPUS group. On day 10, total RNA was extracted from both sets of cultures and hybridized to microarray slides, the data sets were analysed. Markers for differentiated osteoblasts and osteocytes, as well as collagen-related genes, cell adhesion factors were up-regulated in LIPUS group on day 10. Gene expression in response to LIPUS treatment of bone marrow cells were measured on day 10 after cultures were established. Experiments were performed at each conditions (LIPUS or Control).