Biological Role of miRNA-302a-3p/DKK1 in Osteogenesis of Bone-Marrow Derived Mesenchymal Stem Cells

Abstract

To elucidate the involvement of miRNA-302a-3p in osteogenesis of BMSCs through targeting DKK1, thus influencing the progression of osteoporosis (OP). MiRNA-302a-3p levels in serum of 40 OP patients and 40 healthy controls were detected by qRT-PCR. BMD was determined in OP patients expressing high or low level of miRNA-302a-3p. In BMSCs undergoing osteogenesis at the different time points, dynamic expressions of ALP, RUNX2 and Bglap were determined. Influences of miRNA-302a-3p on ALP activity and osteogenic capacity in BMSCs were assessed by ALP activity determination, ALP staining and ARS. The interaction between miRNA-302a-3p and DKK1 was verified by dual-luciferase reporter gene assay and Spearman correlation test. In addition, DKK1 involvement in osteogenesis of BMSCs influenced by miRNA-302a-3p was evaluated. MiRNA-302a-3p level was reduced in serum of OP patients. BMD was higher in OP patients expressing high level of miRNA-302a-3p. During the process of osteogenesis, overexpression of miRNA-302a-3p upregulated osteogenesis-associated genes, ALP activity and capacity of mineralization in BMSCs. Knockdown of miRNA-302a-3p achieved the opposite trends. DKK1 was identified to be the target gene binding miRNA-302a-3p, and its level was negatively regulated by miRNA-302a-3p. Notably, DKK1 was responsible for accelerating osteogenesis in BMSCs regulated by miRNA-302a-3p. Downregulation of MiRNA-302a-3p inhibits osteogenesis in BMSCs via downregulating DKK1, thereafter accelerating the progression of OP.