Bone Morphogenic Protein--mRNA upregulation after exposure to low frequency electric field.

PURPOSE

For many years, our laboratory has been investigating different biological substrates for the effects of electromagnetic stimulation proposed in orthopaedic treatments. The results show an acceleration of differentiation at the expense of proliferation. This study using microarray analysis is focused on the cellular mechanisms involved.

METHODS

A microarray analysis (Affymetrix) allowing the screening of the expression of 38,500 genes was used on epidermal cells sampled from three different human donors and distributed within each donor in seven groups of 12 explants, stimulated at different times, to compare control. Modifications of the expression of BMP-2, 4 and 7 were studied at days four, seven and 12.

RESULTS

The expression of BMP-2 was significantly increased at day 12 on the stimulated samples. J(4) and J(7) did not show any significant difference nor did the expression of BMP-4 and 7 at the different times.

CONCLUSION

The results obtained in previous experiments on cellular substrates, bone embryonic tissue and clinical series were all consistent with the increase of BMP-2. Other publications have confirmed an increase of BMP-2 under electric or electromagnetic stimulation. The increase of BMP-2 appears as an effect of the electromagnetic field stimulations applied in orthopaedics. This observation contributes towards possible indications and a better understanding of the cellular mechanism.