Lentiviral-mediated BMP-2 gene transfer enhances healing of segmental femoral defects in rats.
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 5x10(6) 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 1x10(6) 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.
Hsu
W K
WK
Department of Orthopaedic Surgery, David Geffen School of Medicine at UCLA, UCLA, Center for Health Sciences 76-134, 10833 LeConte Avenue, Los Angeles, CA 90095, USA.
Sugiyama
O
O
Park
S H
SH
Conduah
A
A
Feeley
B T
BT
Liu
N Q
NQ
Krenek
L
L
Virk
M S
MS
An
D S
DS
Chen
I S
IS
Lieberman
J R
JR
D000818:Animals; D001696:Biomechanical Phenomena; D001854:Bone Marrow Cells / Q000378:metabolism; D016026:Bone Marrow Transplantation; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000096:biosynthesis / Q000235:genetics*; D005260:Female; D005269:Femur / Q000293:injuries / Q000473:pathology / Q000502:physiology; D017102:Fracture Healing / Q000235:genetics*; D015870:Gene Expression; D018014:Gene Transfer Techniques; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics; D066298:In Vitro Techniques; D016086:Lentivirus / Q000235:genetics; D051381:Rats; D011917:Rats, Inbred Lew; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D017154:Stromal Cells / Q000378:metabolism / Q000637:transplantation; D016212:Transforming Growth Factor beta / Q000096:biosynthesis / Q000235:genetics*
C525720:Bmp2 protein, rat; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins