J Korean Soc Endocrinol.  2006 Jun;21(3):192-203. 10.3803/jkes.2006.21.3.192.

Retrovirus Mediated Gene Transfer of RANK-Fc Ameliorates Bone Loss in a Mouse Ovariectomy Model of Osteoporosis

• Kim D
• Shin CS

• KMID: 2200731
• DOI: http://doi.org/10.3803/jkes.2006.21.3.192

Abstract

BACKGROUND: Interactions between the receptor activator of the NF-kappaB ligand (RANKL) and its receptor, RANK, are important in the terminal differentiation and activation of osteoclasts. In the current investigation, we examine the feasibility of using genetically modified mesenchymal stem cells (MSCs), C3H10T1/2 cells as a platform for the sustained systemic delivery of therapeutic proteins into the circulation in an osteoporosis model, and investigate retroviral-mediated gene therapy of RANK-Fc as a means of ameliorating ovariectomy (OVX)-induced bone resorption.
METHODS
C3H10T1/2 cells were transduced with a MSCV-based retroviral vector containing cDNA of a fusion protein combining the extracellular domain of murine RANK with the human immunoglobulin constant domain (MSCV-RANK-Fc-eGFP). Young adult female mice were subjected to OVX or sham surgery, followed by treatment with transduced cells or PBS 4 weeks later. The expression of RANK-Fc by these cells was assessed, both in vitro and in vivo. Total bone mineral density (BMD) was measured and GFP expression was examined.
RESULTS
Transduced cells produced biologically active RANK-Fc in vitro and in vivo. Mice that were subjected to OVX followed by treatment with cells transduced with MSCV-RANK-Fc-eGFP 4 weeks later contained no significant but higher total BMD than either the control vector or PBS-treated mice after 8 weeks. Higher GFP expression was attained in the liver, spleen, and intra-abdominal fat of mice treated with MSCV-RANK-Fc-eGFP.
CONCLUSION
The data collectively indicate that C3H10T1/2 cells are effectively transduced with a MSCV-based retrovirus, and are capable of secreting biologically active RANK-Fc in vitro and in vivo. Moreover, gene therapy facilitating the sustained delivery of RANK-Fc may be an effective method to reverse OVX-induced osteoporosis.

MeSH Terms

Animals
Bone Density
Bone Resorption
DNA, Complementary
Female
Genetic Therapy
Humans
Immunoglobulins
Intra-Abdominal Fat
Liver
Mesenchymal Stromal Cells
Mice*
NF-kappa B
Osteoclasts
Osteoporosis*
Ovariectomy*
Retroviridae*
Spleen
Young Adult
Zidovudine
DNA, Complementary
Immunoglobulins
NF-kappa B
Zidovudine