Objective:Bone tissue engineering provides new methods to repair bone defects in oral and maxillofacial region,and human adipose-derived stem cells(hASCs)as seed cells is the key point.Tensile stress can promote the osteogenic differentiation of hASCs in vitro.Methods:Microarray analysis data showed that Let-7i was markedly downregulated in hASCs under tensile stress treatment.Bioinformatic analysis and luciferase reporter assays revealed that Wnt10b was a direct target of Let-7i.Results:Under tensile stress,mimics-mediated gain-function studies revealed that forced expression of Let-7i inhibited osteogenic differentiation of hASCs,whereas inhibition of Let-7i by inhibitor obviously promoted osteogenic differentiation.Furthermore,Let-7i overexpression decreased activity of the Wnt/β-catenin pathway,as indicated by lower expression of Wnt10b,active β-catenin in Let-7i-treated hASCs.By contrast,Let-7i inhibition activated the Wnt/β-catenin pathway.Conclusion:Taken together,these results demonstrate that,under tensile stress,Let-7i negatively regulates hASCs osteogenic differentiation through the Wnt/β-catenin pathway by directly targeting Wnt10b.