Lentiviral-mediated BMP-2 gene transfer enhances healing of segmental femoral defects in rats

• Published in: Bone (New York, N.Y.) Vol. 40; no. 4; pp. 931 - 938
• Main Authors: Hsu, W.K, Sugiyama, O, Park, S.H, Conduah, A, Feeley, B.T, Liu, N.Q, Krenek, L, Virk, M.S, An, D.S, Chen, I.S, Lieberman, J.R
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-04-2007; Elsevier Science
• Subjects: Animals; Biological and medical sciences; Biomechanical Phenomena; BMP-2; Bone; Bone Marrow Cells - metabolism; Bone Marrow Transplantation; Bone morphogenetic protein; Bone Morphogenetic Protein 2; Bone Morphogenetic Proteins - biosynthesis; Bone Morphogenetic Proteins - genetics; Female; Femoral defect; Femur - injuries; Femur - pathology; Femur - physiology; Fracture Healing - genetics; Fundamental and applied biological sciences. Psychology; Gene Expression; Gene therapy; Gene Transfer Techniques; Green Fluorescent Proteins - biosynthesis; Green Fluorescent Proteins - genetics; In Vitro Techniques; Lentivirus; Lentivirus - genetics; Orthopedics; Rats; Rats, Inbred Lew; Recombinant Proteins - biosynthesis; Recombinant Proteins - genetics; Stromal Cells - metabolism; Stromal Cells - transplantation; Transforming Growth Factor beta - biosynthesis; Transforming Growth Factor beta - genetics; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Bone morphogenetic protein; Bone; Gene therapy; BMP-2; Femoral defect; Lentivirus; Femur; Rat; Rodentia; Diseases of the osteoarticular system; Retroviridae; Virus; Vertebrata; Mammalia; Treatment; Animal; Morphology; Bone marrow; Bone defect; Stromal cell; Cicatrization
• ISSN: 8756-3282; 1873-2763
• DOI: 10.1016/j.bone.2006.10.030

Abstract The objective of the present study was to assess the ability of bone marrow cells expressing BMP-2 created via lentiviral gene transfer to heal a critical sized femoral defect in a rat model. Femoral defects in Lewis rats were implanted with 5 × 106 rat bone marrow stromal cells (RBMSC) transduced with a lentiviral vector containing either the BMP-2 gene (Group I), the enhanced green fluorescent protein (LV-GFP) gene (Group IV), or RBMSC alone (Group V). We also included femoral defects that were treated with BMP-2-producing RBMSC transduced with lentivirus, 8 weeks after infection (Group III), and a group with 1 × 106 RBMSC transduced with a lentiviral vector with the BMP-2 gene (Group II). All defects (10/10) treated in Group I healed at 8 weeks compared with none of the femora in the control groups (Groups IV and V). In Group II, only one out of 10 femora healed. In Group III, 5 out of 10 femora healed. Significantly higher amounts of in vitro BMP-2 protein production were detected in Groups I, II, and III when compared to that of the control groups ( p < 0.05). Histomorphometric analysis revealed significantly greater total bone volume in defects in Group I and III when compared to control specimens ( p < 0.003). Biomechanical testing revealed no significant differences in the healed defects in Groups I and III when compared to intact, nonoperated femora with respect to peak torque and torque to failure. Our results indicate that BMP-2-producing RBMSC created through lentiviral gene transfer have the capability of inducing long-term protein production in vitro and producing substantial new bone formation in vivo.