Bone Mesenchymal Stem Cells Transplanted into Rabbit Intervertebral Discs Can Increase Proteoglycans

We sought to determine whether transplanted allogeneic bone mesenchymal stem cells can survive and increase the amount of proteoglycans in intervertebral discs. We used the rabbit intervertebral disc as a model, creating three groups: an uninjected control group, a group injected with saline, and a group injected with 1 × 105 of bone mesenchymal stem cells containing trace marker gene LacZ from young rabbits. At 1, 3, and 6 months, X-gal staining and DNA-polymerase chain reaction of the neomycin-resistant gene were used to ascertain cell location. Reverse transcription-polymerase chain reaction and enzyme-linked immunosorbant assay analysis were done to evaluate the effect on the disc matrix. Transplanted mesenchymal stem cells were located and identified in the group injected with mesenchymal stem cells, whereas we detected none in the saline and control groups. The amount of mRNA and protein of proteoglycan and collagen Type II in the mesenchymal stem cells group was increased, whereas the amount of collagen Type I did not change. We found no changes in the saline group. Our data suggest transplanted allogenic bone mesenchymal stem cells can survive and increase proteoglycan amount, supporting its potential use as a treatment of intervertebral disc degeneration.