MiR-145 regulates osteogenic differentiation of human adipose-derived mesenchymal stem cells through targeting FoxO1.

In this study， we aimed to investigate the expression of miR-145 before and after hASCs osteogenic differentiation. We also intended to explore the influence of the target relationship between miR-145 and FoxO1 on osteogenic differentiation. Dual-luciferase reporter gene assay and real-time PCR were used to confirm the target relationship between miR-145 and FoxO1. Furthermore， the modulatory effects of miR-145 and FoxO1 on hASCs osteoinductive differentiation were measured by real-time PCR ， Western blot， ALP staining， ARS staining， and cell immunofluorescence assay. After osteogenic differentiation， miR-145 was gradually down-regulated， while FoxO1 was up-regulated in hASCs. MiR-145 could directly target FoxO1 3'UTR. FoxO1 was negatively regulated by miR-145. After osteoinductive differentiation， BSP， Ocn， and OPN expression was lowered with the overexpression of miR-145 or the knockdown of FoxO1. Furthermore， ALP and ARS staining assay results showed weakened ALP activity and extracellular matrix calcification. When overexpressing miR-145 and FoxO1 simultaneously， no obvious change in ALP activity and extracellular matrix calcification was seen. MiR-145 could suppress hASCs osteoinductive differentiation by suppressing FoxO1 directly. Impact statement Researching on ASCs was a promising strategy to study osteogenic differentiation. The regulatory role of miR-145 on hASCs osteogenic differentiation remained partially explored. Our study revealed a novel mechanism of the osteogenic differentiation process and suggested that miR-145 and its target gene FoxO1 may be potential targets for the therapy of human osteogenic-related disorders.