Abstract: Objective　To investigate the effect and mechanism of estrogen combined with mechanical tension on human periodontal ligament fibroblasts. Methods　hPDLF cells were sorted and identified by magnetic beads. The hPDLF cells were divided into the control group, 17β-estradiol group, mechanical tension group and 17β-estradiol combined with mechanical tension group. Cell proliferation was measured; alizarin red staining was used to detect osteogenic differentiation of hPDLF cells. qRT-PCR was used to detect osteogenic gene mRNA expression, and Western blot was used to detect osteogenic protein, estrogen receptor expression, and activation of Akt signaling pathway. Results　It was identified that the extracted hPDLF cells conformed to its characteristics. The cell proliferation ability and OD-value of alizarin red staining in the 17β-estradiol and mechanical tension groups were significantly higher than those in the control group. The estrogen receptor ER-β and osteogenic genes RUNX2, OCN, OSX, OPN expression, Akt phosphorylation level were significantly higher than those of control group. Estrogen combined with mechanical tension cell proliferation ability, alizarin red staining OD value was significantly higher than the 17β-estradiol and mechanical tension group. The expression of estrogen receptor ER-β, osteogenic genes RUNX2, OCN, OSX, OPN, Akt phosphorylation level were significantly higher than those of 17β-estradiol and mechanical tension group. Conclusion　Estrogen combined with mechanical tension can promote osteogenic differentiation of hPDLF cells, and promote the expression of estrogen receptors and osteogenic genes, as well as the activation of Akt signaling pathway.

Key words: estrogen combined with mechanical tension, osteogenic differentiation, mechanism