Objective To investigate the role of miR-194-3p in regulating functional changes in osteoblasts in a simulated microgravity environment and to provide a theoretical foundation for understanding the mechanical response mechanisms of osteoblasts in extreme mechanical environments.Methods The effects of microgravity on osteoblasts were simulated by using a rotary cell culture system.MC3T3-E1 osteoblasts were transfected with an miR-194-3p inhibitor and changes in proliferation,differentiation,apoptosis,and mineralization were assessed using MTT assay,RT-PCR,Western blot,double fluorescence staining,and alizarin red staining.Results Elevated expression of miR-194-3p under simulated microgravity conditions led to the suppression of osteoblast proliferation,differentiation,and mineralization to a certain extent,while promoting osteoblast apoptosis.However,transfection with the miR-194-3p inhibitor significantly downregulated miR-194-3p expression and partially reversed the reduced osteoblast proliferation,decreased expression of osteogenic differentiation markers such as ALP,OCN,and COL-I genes and proteins,decreased bone mineralization nodules,and increased osteoblast apoptosis induced by microgravity exposure.These findings indicated that miR-194-3p effectively ameliorates abnormal osteoblast function under microgravity conditions.Conclusions MiR-194-3p acts as a negative regulatory factor in the mechanical responses of osteoblasts under simulated microgravity.