Intermittent hydrostatic compression promotes nitric oxide production and osteodifferentiation of fetal dural cells

Purpose: The aim of these studies was to evaluate the biologic response of fetal dural cell cultures to compressive mechanical force. Methods: Primary cell cultures from the dura mater of E18 CD-1 mice were subjected to 2 PSI of intermittent hydrostatic compression (IHC) at a frequency of 0.5 Hz. Quantitative measures of the expression of Osterix (Osx), osteopontin (OP), endothelial nitric oxide synthase (eNOS) and Noggin were performed by RT-PCR following 3, 6, and 12 hours of exposure to IHC. Nitric oxide production was quantified through the measurement of NO metabolites following 6 hours of exposure to IHC. Results: IHC resulted in an increase in Osx, OP, and eNOS expression compared with controls at all time points. The expression of Noggin decreased at all time points. Exposure to IHC resulted in a significant increase in the production of NO metabolites at 6 hours when compared with controls. Conclusions: These experiments indicate that dural cell biology is significantly altered following exposure to IHC. Specifically, IHC promotes production of NO and osteodifferentiation in fetal dural cell cultures, with increases in the expression of osteoinductive genes and decreases in inhibitors of osteogenesis.