Human and Dogs’ Gingival Stem Cells are Different

Objective:To test the hypothesis that human and canine gingival mesenchymal stem cells have similar stem cell characteristics and that low intensity pulsed ultrasound (LIPUS) enhances these characteristics. Method:Human and canine gingival mesenchymal cells (HGMCs and CGMCs) were isolated, expanded then each population was divided into two subgroups, one subgroup was treated by LIPUS for 20 minutes and the other subgroup was served as control.LIPUS was applied using an ultrasound device that produces spatial average temporal average intensity of 30 mW/cm 2 .Pulses are 1.5 MHz and pulse repetition frequency is 1 kHz.24 hours later, cells were collected and evaluated by flowcytometry for stem cell markers CD11b; CD14; CD34; CD45; CD73; CD90 and CD105.Also, cells were also cultured in regular Alpha DMEM or osteogenic media.Alkaline phostphatase, DNA and MTT analyses were performed. Result:Flow cytometry analysis showed that control and LIPUS treated canine CGMCs were partially positive only for CD90 and negative for the rest of the stem cell markers.However CD90 expression was decreased (5%) by LIPUS compared to non LIPUS treated CGMCs.On the other hand, HGMCs showed higher CD73, CD90, and CD105 expression than CGMCs.In addition, LIPUS enhanced these stem cell markers expression in HGMCs.MTT was increased in HGMCs in regular or osteogenic medium, while it was increased only in CGMCs in osteogenic medium.ALP was significantly increased in HGMCs when cultured in osteogenic medium with or without LIPUS application.No difference between CGMCs and HGMCs with respect to DNA expression. Conclusion:HGMCs show more multipotent potential with or without LIPUS application compared to CGMCs, especially when they were cultured in osteogenic medium.