Human mesenchymal stem cells implantation into the degenerated coccygeal disc of the rat.

In this study, the authors explored the effect of human mesenchymal stem cell (MSC) implantation on the restoration of degenerative intervertebral discs (IVDs) in the rat. A unique rat coccygeal model was used to investigate the effects of transplanting human MSCs and to examine MSC survival in degenerative discs. MSC implantations into rat coccygeal IVDs were performed at 2 weeks post-injury. Radiologic and histologic evaluations were performed at 2, 4, 6, and 8 weeks post-injury. MSC-injected segments (TS) retained disc height and signal intensity, but injured non-injected segment (IS) progressively lost disc height. Pathological results revealed that the TS group showed relative restoration of the inner annulus structure; however, the IS group showed destruction of the inner annulus structure. Immunohistochemical staining using Anti-Human Nucleic Antibody (#MAB1281 Chemicon) revealed positive staining in the TS group at 2 weeks post-transplantation (4 weeks post-injury). This study shows that human MSCs survive for 2 weeks after transplantation into the IVDs of rats, and that MSCs increased the heights and signal intensities of intervertebral disc.