Adeno-associated virus-mediated BMP-7 and SOX9 in vitro co-transfection of human degenerative intervertebral disc cells

Bone morphogenetic protein-7 (BMP-7) and SOX9 are important transcription factors in chondrogenesis. In this study, we examined the biological function of the adeno-associated virus (AAV)-mediated BMP-7 and SOX9 double gene in vitro co-transfection of nucleus pulposus cells of human degenerative intervertebral disc. Human intervertebral disc nucleus pulposus cells were cultured in vitro and subcultured for 5 generations. Using rAAV-BMP-7 and rAAV-SOX9 AAV2-type AAV viruses, the cells were divided into 4 groups: blank normal, BMP-7 transfection, SOX9 transfection, and BMP-7 and SOX9 co-transfection. After 48 h, expression of type II collagen and its mRNA in nucleus pulposus cells was determined. The expression of type II collagen in BMP-7 transfection, SOX9 transfection, and co-transfection groups was up-regulated to varying degrees compared to the blank control group. The type II collagen mRNA level expression in the co-transfection group was significantly higher than in other groups (P < 0.05). AAV-mediated BMP-7 and SOX9 in vitro co-transfection can promote the synthesis of type II collagen in nucleus pulposus cells in the human degenerative intervertebral disc. Double-gene therapy has a synergistic effect in the treatment of intervertebral disc degeneration.