| Objective To investigate the effects of different mechanical stretch intensity on osteogenic differentiation and lncRNA H19 expression of Bone marrow mesenchymal stem cells (BMSCs). Methods The primary BMSCs of C57BL/6 mice were extracted, cultured and identified. Mechanical stretching was performed with the Flexcell 5000 cell stress loading system, the program was frequency of 0.5 Hz, continuous stretching for 7 days, stretching intensity of 4 % and 6 %, and single stretching time of 0, 2, 4, 6 and 8 h. After the intervention, RT-PCR was used to verify the relative expression of lncRNA H19 and osteogenic marker OCN mRNA, western blot was used to detect the relative expression of Runx2 protein, and ALP staining was used to detect the osteogenic differentiation ability. Results Both 4 % and 6 % mechanical distraction interventions could promote the osteogenic differentiation of BMSCs and the expression of lncRNA H19. At 4 % tensile intensity, it continued to increase within 6 h and decreased at 8 h; At 6 % tensile intensity, it continued to increase within 4 h and decreased at 6 h, but still higher than 0 h. Conclusion Under the stimulation of fixed distraction intensity, within a certain time range, the increase of distraction time can promote the osteogenic differentiation of BMSCs, while prolonged distraction is not conducive to osteogenic differentiation. The optimal distraction regimen for promoting osteogenic differentiation and lncRNA H19 expression determined in this experiment was 6% distraction intensity, 4 h/day, continuous distraction for 7 days, and a frequency of 0.5 Hz. |