Study Design. Prospective, randomized, and controlled animal study.
Objective. To observe extracellular matrix (ECM) changes in degenerative intervertebral disc (IVD) after transplantation of bone marrow mesenchymal stem cells (BMSCs) virally transfected with a construct expressing “human tissue inhibitor of metalloproteinase 1” (hTIMP-1), and to discuss the feasibility of using this approach to treat IVD degeneration.
Summary of Background Data. Intervertebral disc (IVD) degeneration is characterized by decreased cell numbers, bioactivity of the nucleus pulposus, and remodeled ECM. Exogenous genes can be targeted into cells to produce inhibition of ECM degradation and increase ECM content in IVDs, and thereby potentially stop or reverse degenerative processes and modify disc structure.
Methods. BMSCs were isolated from a pure New Zealand white rabbit and identified by flow cytometry. Transgenic BMSCs were acquired by transfection with a recombinant adenovirus vector carrying the hTIMP-1 gene. Animal models of IVD degeneration were established by annulus puncture and then given intra-nucleus pulposus injections according to their random assignment into 3 groups: (1) a transgenic BMSC transplantation (TgBT) group that received BMSCs transfected with an hTIMP-1–expressing adenovirus vector; (2) a BMSC transplantation (BT) group that received unaltered BMSCs; and (3) a control group that received cell-free phosphate-buffered saline. Degree of degeneration was evaluated 12 weeks after modeling. ECM content was quantified using immunohistochemistry and spectrophotography. Expression of hTIMP-1 was observed via quantitative polymerase chain reaction, western blot, and immunohistochemistry.
Results. Significantly fewer degenerative changes and increased ECM content were observed in the TBT and BT groups than the control group animals (P < 0.05). The TBT group had greater ECM content than did the BT group (P < 0.05), as well as higher levels of hTIMP-1 mRNA and protein.
Conclusion. Transplantation of BMSCs transfected with hTIMP-1 can increase ECM content by inhibiting ECM degradation and promoting ECM synthesis.
Level of Evidence: N/A
Transplantation of human tissue inhibitor of metalloproteinase 1 (hTIMP-1)–expressing bone marrow mesenchymal stem cells (BMSCs) in a rabbit model of intervertebral disc degeneration (IDD) reversed or delayed IDD, through the dual action of exogenous hTIMP-1 expression (which inhibited extracellular matrix degradation) and BMSC transplantation (which promoted extracellular matrix synthesis).
*Department of Orthopedics, The First Affiliated Hospital, China Medical University, Shenyang, China; and
†Department of Orthopedics, The Second Affiliated Hospital, Shenyang Medical College, Shenyang, China.
Address correspondence and reprint requests to Tu Guanjun, MD, PhD, Department of Orthopedics, The First Affiliated Hospital, China Medical University, Shenyang 110001, China; E-mail: firstname.lastname@example.org
Acknowledgment date: September 18, 2013. Revision date: November 21, 2013. Acceptance date: January 7, 2014.
The manuscript submitted does not contain information about medical device(s)/drug(s).
National Natural Science Foundation of China (grant no. 81070971) and Shenyang Medical College Technology Foundation (grant no. 20121014) funds were received in support of this work.
No relevant financial activities outside the submitted work.