Effects of Direct Current Electrical Stimulation on Gene Expression of Osteopromotive Factors in a Posterolateral Spinal Fusion Model

Study Design. An in vivo model was used to determine levels of mRNA expression in response to direct current (DC) electrical stimulation in a rabbit posterolateral fusion model. Objectives. This study tested the possibility that DC stimulation at the surgery site would increase expression of genes related to bone formation relative to expression in autograft alone. Summary of Background Data. DC electrical stimulation as an adjunct treatment in spinal surgery has shown increased fusion rates when compared with autograft alone, yet the biology of such treatment is not fully understood. Methods. Thirty New Zealand White rabbits were entered into the study. A posterolateral, intertransverse process fusion was performed bilaterally at L4–L5, with autogenous bone graft. An implantable DC stimulator was placed across the decorticated transverse processes before placement of autograft. Animals were killed at 3, 7, 14, 21, and 28 days. mRNA levels of BMP-2, 4, 6, 7, VEGF, FGF-2, TGF-β, ALK-2, and ALK-3 were evaluated with real-time RT-PCR. Results. mRNA expression was significantly higher in the DC stimulated animals versus the control animals for several of the genes studied. In particular, levels of mRNA were elevated for BMP-2, BMP-6, and BMP-7. Conclusions. This study shows for the first time that DC stimulation results in a sustained increase of multiple osteogenic genes, suggesting that the biologic mechanism for the DC-induced increase in the rate and extent of bone formation observed clinically may be mediated by the up-regulation of these osteoinductive factors.

[1]  S. Cook,et al.  In Vivo Evaluation of Recombinant Human Osteogenic Protein (rhOP-1) Implants As a Bone Graft Substitute for Spinal Fusions , 1994, Spine.

[2]  V. Rosen,et al.  Recombinant human bone morphogenetic protein-2 stimulates osteoblastic maturation and inhibits myogenic differentiation in vitro , 1991, The Journal of cell biology.

[3]  J. France,et al.  The Efficacy of Direct Current Stimulation for Lumbar Intertransverse Process Fusions in an Animal Model , 2001, Spine.

[4]  J. Black,et al.  The Mechanism of Faradic Stimulation of Osteogenesis , 1987 .

[5]  J. Bubis,et al.  Stimulation of Bone Formation by Electrical Current on Spinal Fusion , 1986, Spine.

[6]  J M Toth,et al.  Direct Current Electrical Stimulation Increases the Fusion Rate of Spinal Fusion Cages , 2000, Spine.

[7]  W. Hutton,et al.  The Marshall R. Urist Young Investigator Award. Gene expression during autograft lumbar spine fusion and the effect of bone morphogenetic protein 2. , 1998, Clinical orthopaedics and related research.

[8]  Allen J. Meril.  Direct Current Stimulation of Allograft in Anterior and Posterior Lumbar Interbody Fusions , 1994, Spine.

[9]  E. Dawson.  Bone morphogenetic proteins BMPs. Letter. , 2003, The spine journal : official journal of the North American Spine Society.

[10]  C. Bünger,et al.  Bone graft incorporation around titanium-alloy- and hydroxyapatite-coated implants in dogs. , 1992, Clinical orthopaedics and related research.

[11]  R. Puno,et al.  The Use of Implantable Direct Current Stimulation in Multilevel Spinal Fusion Without Instrumentation: A Prospective Clinical and Radiographic Evaluation With Long‐Term Follow‐Up , 1996, Spine.

[12]  L. Titus,et al.  The Effect of Nicotine on Gene Expression During Spine Fusion , 2000, Spine.

[13]  J. Lane.  BMPs: why are they not in everyday use? , 2001, The Journal of bone and joint surgery. American volume.

[14]  M. Magin,et al.  Improved Lumbar Vertebral Interbody Fusion Using rhOP-1: A Comparison of Autogenous Bone Graft, Bovine Hydroxylapatite (Bio-Oss), and BMP-7 (rhOP-1) in Sheep , 2001, Spine.

[15]  M. Laursen,et al.  Recombinant bone morphogenetic protein-7 as an intracorporal bone growth stimulator in unstable thoracolumbar burst fractures in humans: preliminary results , 1999, European Spine Journal.

[16]  D. Bushinsky.  Metabolic alkalosis decreases bone calcium efflux by suppressing osteoclasts and stimulating osteoblasts. , 1996, The American journal of physiology.

[17]  S. Arnoczky,et al.  The Efficacy of Direct Current Electrical Stimulation to Enhance Canine Spinal Fusions , 1990, Clinical orthopaedics and related research.

[18]  S. Cook,et al.  Use of an osteoinductive biomaterial (rhOP-1) in healing large segmental bone defects. , 1998, Journal of orthopaedic trauma.

[19]  J. Kanczler,et al.  Effect of faradic products on direct current-stimulated calvarial organ culture calcium levels. , 1999, Biochemical and biophysical research communications.

[20]  M. Fukase,et al.  Second messenger signaling in the regulation of cytosolic pH and DNA synthesis by parathyroid hormone (PTH) and PTH‐related peptide in osteoblastic osteosarcoma cells: Role of Na+/H+ exchange , 1992, Journal of cellular physiology.

[21]  H. Feuer,et al.  The use of electrical stimulation to enhance spinal fusion. , 2002, Neurosurgical focus.

[22]  S. Boden.  The biology of posterolateral lumbar spinal fusion. , 1998, The Orthopedic clinics of North America.

[23]  M. Swiontkowski,et al.  Update on human rights issues in clinical research. , 2001, The Journal of bone and joint surgery. American volume.

[24]  I. Reid,et al.  Parathyroid hormone depresses cytosolic pH and DNA synthesis in osteoblast-like cells. , 1988, The American journal of physiology.

[25]  W. Kane,et al.  Direct Current Electrical Bone Growth Stimulation for Spinal Fusion , 1988, Spine.

[26]  S. Bulstra,et al.  Osteogenic activity of OP-1 bone morphogenetic protein (BMP-7) in a human fibular defect. , 1999, The Journal of bone and joint surgery. British volume.

[27]  L Jiang,et al.  Osteogenesis of Electrically Stimulated Bone Cells Mediated in Part by Calcium Ions , 1998, Clinical orthopaedics and related research.

[28]  W C Hutton,et al.  An Experimental Lumbar Intertransverse Process Spinal Fusion Model: Radiographic, Histologic, and Biomechanical Healing Characteristics , 1995, Spine.

[29]  S. Cook,et al.  The effect of recombinant human osteogenic protein-1 on healing of large segmental bone defects. , 1994, The Journal of bone and joint surgery. American volume.

[30]  M. Oursler,et al.  Temporal expression patterns of BMP receptors and collagen II (B) during periosteal chondrogenesis , 2002, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[31]  J. Kanczler,et al.  Pulsed Electromagnetic Fields Simultaneously Induce Osteogenesis and Upregulate Transcription of Bone Morphogenetic Proteins 2 and 4 in Rat Osteoblastsin Vitro , 1998 .

[32]  T. Kawase,et al.  Effects of prostaglandin E2 and F2α on cytoplasmic pH in a clonal osteoblast‐like cell line, MOB 3–4 , 1991, Journal of cellular physiology.

[33]  S D Cook,et al.  Effect of recombinant human osteogenic protein-1 on healing of segmental defects in non-human primates. , 1995, The Journal of bone and joint surgery. American volume.

[34]  J. Wozney,et al.  Characterization of rhBMP-2 pharmacokinetics implanted with biomaterial carriers in the rat ectopic model. , 1999, Journal of biomedical materials research.

[35]  J. Kanczler,et al.  Pulsed electromagnetic fields simultaneously induce osteogenesis and upregulate transcription of bone morphogenetic proteins 2 and 4 in rat osteoblasts in vitro. , 1998, Biochemical and biophysical research communications.

[36]  S. Cook,et al.  Osteogenic protein-1: biology and applications. , 1996, Clinical orthopaedics and related research.

[37]  D. Kucharzyk.  A controlled prospective outcome study of implantable electrical stimulation with spinal instrumentation in a high-risk spinal fusion population. , 1999, Spine.

[38]  A. Rogozinski,et al.  Efficacy of Implanted Bone Growth Stimulation in Instrumented Lumbosacral Spinal Fusion , 1996, Spine.

[39]  S. Vukicevic,et al.  Regulation of BMP‐7 expression by retinoic acid and prostaglandin E2 , 2002, Journal of cellular physiology.

[40]  Christian Lattermann,et al.  A gene therapy approach to accelerating bone healing Evaluation of gene expression in a New Zealand white rabbit model , 1999, Knee Surgery, Sports Traumatology, Arthroscopy.

[41]  W. Hayes,et al.  In vivo evaluation of coralline hydroxyapatite and direct current electrical stimulation in lumbar spinal fusion. , 1999, Spine.

[42]  S. Cook,et al.  Recombinant human bone morphogenetic protein-7 induces healing in a canine long-bone segmental defect model. , 1994, Clinical orthopaedics and related research.

[43]  T. K. Hunt,et al.  Hydrogen peroxide stimulates macrophage vascular endothelial growth factor release. , 2001, American journal of physiology. Heart and circulatory physiology.

[44]  B. Cunningham,et al.  Osteogenic protein versus autologous interbody arthrodesis in the sheep thoracic spine. A comparative endoscopic study using the Bagby and Kuslich interbody fusion device. , 1999, Spine.

[45]  F. Glorieux,et al.  Temporal and spatial expression of bone morphogenetic protein-2, -4, and -7 during distraction osteogenesis in rabbits. , 2000, Bone.