Distal Low Homeobox 3 Promotes Bone Marrow Mesenchymal Stem Cells Osteogenic Differentiation and Bone Synthesis and Ameliorates Osteoporosis by Activating Typical Wnt Signaling

Abstract

The distal low homeobox 3 (DLX3) regulates the bone marrow mesenchymal stem cells (BMSC) osteogenic differentiation. However, whether DLX3 affects osteoporosis (OP) remains unclear. An OVX-induced OP rat model was constructed and DLX3 plasmid was injected followed by analysis of bone mineral density and ALP activity. Rat BMSCs were isolated and divided into control group, OP group and DLX3 group (transfected with DLX3 plasmid) followed by analysis of chondrocytes survival rate by MTT assay, Caspase 3 activity, type I collagen and Osterix expression by Real time PCR and -catenin level by Western blot. DLX3 expression was significantly down-regulated in OP rats with deceased bone density and ALP activity compared to sham group (P < 0 05). When DLX3 was transfected into OP rats, DLX3 expression was significantly up-regulated with increased bone density and ALP activity compared with OP group (P < 0 05). BMSCs survival was significantly decreased in OP group and Caspase 3 activity was significantly increased with downregulated type I collagen, Osterix and -catenin (P < 0 05). However, transfection of DLX3 plasmid into OP group BMSCs cells can significantly reverse the above changes, compared to OP group (P < 0 05). DLX3 expression is reduced in osteoporosis. Up-regulation of DLX3 can promote osteogenic differentiation of BMSCs by regulating typical Wnt signaling, promote differentiation into osteoblasts, increase bone density increase, and then ameliorate osteoporosis.