Abstract: Objective: To evaluate the impact of BMP-6 on the osteogenesis of rat bone marrow-derived mesenchymal stem cells under tensile stress. Methods: Different tensile stress was applied on rat BMMSCs by four-point bending apparatus for 60 minutes. Two hours later, the changes of the BMP-6 mRNA level and alkaline phosphate, osteocalcin and runt-related transcription factor 2 mRNA level were examined. Then under the poor osteogenesis condition(4000μstrain), the BMP-6 adenovirus transfected BMMSCs and control BMMSCs were also performed the same test to evaluate the osteogenic ability. Results: With the increase of tensile stress, the expression of BMP-6 was gradually increased, so was the osteogenic capacity. However, both of the BMP-6 expression and osteogenic capacity decreased obviously after the tensile stress exceeded 2000μstrain. Under the 4000μstrain stress tensile, the transfected cells presented better osteogenic ability than control cells. Conclusion: The proper tensile stress would promote BMP-6 expression and BMMSCs osteogensis. The BMP-6 would recover the compromised osteogenic ability by major stress tensile.

Key words: Tensile stress , Bone marrow-derived mesenchymal stem cells , Adenovirus, BMP