Pulsed Electromagnetic Field Stimulates Cellular Proliferation in Human Intervertebral Disc Cells

다국어 초록 (Multilingual Abstract)

Purpose: The purpose of this study is to investigate the mechanism of cellular proliferation of electromagnetic field (EMF) on human intervertebral disc (IVD) cells.
Materials and Methods: Human IVD cells were cultured three-dimensionally in alginate beads. EMF was exposed to IVD cells with 650 Ϊ, 1.8 millitesla magnetic flux density, 60 Hz sinusoidal wave. Cultures were divided into a control and EMF group. Cytotoxicity, DNA synthesis and proteoglycan synthesis were measured by MTT assay, [3H]-thymidine, and [35S]-sulfate incorporation. To detect phenotypical expression, reverse transcription-polymerase chain reactions (RT-PCR) were performed for aggrecan, collagen type I, and type II mRNA expression. To assess action mechanism of EMF, IVD cells were exposed to EMF with NG-Monomethyl-L-arginine (NMMA) and acetylsalicylic acid (ASA). Results: There was no cytotoxicity in IVD cells with the EMF group in MTT assay. Cellular proliferation was observed in the EMF group (p < 0.05). There was no difference in newly synthesized proteoglycan normalized by DNA synthesis between the EMF group and the control. Cultures with EMF showed no significant change in the expression of aggrecan, type I, and type II collagen mRNA compared to the control group. Cultures with NMMA (blocker of nitric oxide) or ASA (blocker of prostaglandin E2) exposed to EMF demonstrated decreased DNA synthesis compared to control cultures without NMMA or ASA (p < 0.05). Conclusion: EMF stimulated DNA synthesis in human IVD cells while no significant effect on proteoglycan synthesis and chondrogenic phenotype expressions. DNA synthesis was partially mediated by nitric oxide and prostaglandin E2. EMF can be utilized to stimulate proliferation of IVD cells, which may provide efficient cell amplification in cell therapy to degenerative disc disease.

참고문헌 (Reference)

1 Kim H, "Zonal responsiveness of the human intervertebral disc to bone morphogenetic protein-2" 34 : 1834-1838, 2009

2 Colson DJ, "Treatment of delayed- and non-union of fractures using pulsed electromagnetic fields" 10 : 301-304, 1988

3 Holmes GB Jr, "Treatment of delayed unions and nonunions of the proximal fifth metatarsal with pulsed electromagnetic fields" 15 : 552-556, 1994

4 Hiyama A, "Transplantation of mesenchymal stem cells in a canine disc degeneration model" 26 : 589-600, 2008

5 McLeod KJ, "Suppression of a differentiation response in MC-3T3-E1 osteoblast-like cells by sustained, low-level, 30 Hz magnetic-field exposure" 153 : 706-714, 2000

6 Frazer A, "Studies on type II collagen and aggrecan production in human articular chondrocytes in vitro and effects of transforming growth factor-beta and interleukin-1beta" 2 : 235-245, 1994

7 Lin HY, "Repairing large bone fractures with low frequency electromagnetic fields" 28 : 265-270, 2010

8 Foley KT, "Randomized, prospective, and controlled clinical trial of pulsed electromagnetic field stimulation for cervical fusion" 8 : 436-442, 2008

9 Schnoke M, "Pulsed electromagnetic fields rapidly modulate intracellular signaling events in osteoblastic cells: comparison to parathyroid hormone and insulin" 25 : 933-940, 2007

10 Thompson JP, "Preliminary evaluation of a scheme for grading the gross morphology of the human intervertebral disc" 15 : 411-415, 1990

11 Yang X, "Nucleus pulposus tissue engineering: a brief review" 18 : 1564-1572, 2009

12 Hoogendoorn R, "Molecular changes in the degenerated goat intervertebral disc" 33 : 1714-1721, 2008

13 Nishida K, "Modulation of the biologic activity of the rabbit intervertebral disc by gene therapy: an in vivo study of adenovirusmediated transfer of the human transforming growth factor beta 1 encoding gene" 24 : 2419-2425, 1999

14 Katz JN, "Lumbar disc disorders and low-back pain: socioeconomic factors and consequences" 88 : 21-24, 2006

15 Ciombor DM, "Low frequency EMF regulates chondrocyte differentiation and expression of matrix proteins" 20 : 40-50, 2002

16 Maldonado BA, "Initial characterization of the metabolism of intervertebral disc cells encapsulated in microspheres" 10 : 677-690, 1992

17 Chelberg MK, "Identification of heterogeneous cell populations in normal human intervertebral disc" 186 : 43-53, 1995

18 Fitzsimmons RJ, "IGF-II receptor number is increased in TE-85 osteosarcoma cells by combined magnetic fields" 10 : 812-819, 1995

19 Roberts S, "Histology and pathology of the human intervertebral disc" 88 : 10-14, 2006

20 Fitzsimmons RJ, "Growth factors and electromagnetic fields in bone" 21 : 401-406, 1994

21 Yen-Patton GP, "Endothelial cell response to pulsed electromagnetic fields: stimulation of growth rate and angiogenesis in vitro" 134 : 37-46, 1988

22 Borsalino G, "Electrical stimulation of human femoral intertrochanteric osteotomies. Double-blind study" 237 : 256-263, 1988

23 De Mattei M, "Changes in polyamines, c-myc and c-fos gene expression in osteoblast-like cells exposed to pulsed electromagnetic fields" 26 : 207-214, 2005

24 Kim DJ, "Bone morphogenetic protein-2 facilitates expression of chondrogenic, not osteogenic, phenotype of human intervertebral disc cells" 28 : 2679-2684, 2003

25 Moon SH, "Biologic response of human intervertebral disc cells to gene therapy cocktail" 33 : 1850-1855, 2008