Abstract: Objective: To explore the effect of LncRNA MALAT1 on the osteogenic differentiation of adipose-derived mesenchymal stem cells(ADSCs) through the microRNA-34c/SATB2 axis, and to clarify its mechanism. Methods: The human ADSCs were transfected with Lenti-NC, Lenti-MALAT1, sh-NC, sh-MALAT1, miR-NC and miR-34c. RT-PCR method was used to detect the expression levels of LncRNA MALAT1, miR-34c and SATB2 mRNA in the ADSCs. MiRcode and TargetScan 7.1 website were used to predicte and the targeted binding effect between miR-34c and LncRNA MALAT1, miR-34c and SATB2 were verified through luciferase reporter gene experiment; Western blotting method was used to detect the expression levels of osteogenic markers Runx2, OPN and OCN proteins in the ADSCs; ALP staining and Alizarin red S(ARS) staining were used to detect the levels of ALP and ARS and calcium salt deposition in the ADSCs. Results: Compared with day 0, the expression levels of LncRNA MALAT1, SATB2, Runx2, OPN, and OCN proteins in the cells were significantly increased on the 3rd, 7th, 14th, and 21st days after osteogenic induction of ADSCs (P<0.05); the expression levels were significantly reduced (P<0.05). Compared with Lenti-NC group or sh-NC group, the expression level of LncRNA MALAT1,the expression levels of Runx2, OPN and OCN proteins, and the levels of ALP and ARS in the ADSCs in Lenti-MALAT1 group were significantly increased (P<0.01), and the indexes mentioned obove in sh-MALAT1 group were significantly decreased (P<0.01). Compared with miR-NC+Lenti-NC group, the expression levels of Runx2, OPN and OCN proteins in the ADSCs in miR-34c+Lenti-NC group were significantly reduced (P<0.01), and the levels of ALP and ARS were decreased(P<0.01),but the indexes mentioned obove in miR-34c+Lenti-MALAT1 group had no statistically significant differences (P>0.05). Compared with Lenti-NC+miR-NC group, the expression levels of Runx2, OPN and OCN proteins in the ADSCs in Lenti-SATB2+miR-NC group were significantly increased (P<0.01), and the levels of ALP and ARS were significantly increased (P<0.01);but the indexes mentioned above in Lenti-SATB2+miR-34c group had no statistically significant differences(P>0.05). Conclusion: LncRNA MALAT1 promotes the osteogenic differentiation of ADSCs through the miRNA-34c/SATB2 axis.

Key words: long non-coding RNA, metastasis-associated lung adenocarcinoma transcript 1, adipose-derived mesenchymal stem cells, osteogenic differentiation, microRNA-34c, special AT-rich sequence binding protein 2