title: Effects of low- and high-frequency repetitive magnetic stimulation on neuronal cell proliferation and growth factor expression: A preliminary report.
abstract: Repetitive magnetic stimulation is a neuropsychiatric and neurorehabilitation tool that can be used to investigate the neurobiology of sensory and motor functions. Few studies have examined the effects of repetitive magnetic stimulation on the modulation of neurotrophic/growth factors and neuronal cells in vitro. Therefore, the current study examined the differential effects of repetitive magnetic stimulation on neuronal cell proliferation as well as various growth factor expression. Immortalized mouse neuroblastoma cells were used as the cell model in this study. Dishes of cultured cells were randomly divided into control, sham, low-frequency (0.5Hz, 1Tesla) and high-frequency (10Hz, 1Tesla) groups (n=4 dishes/group) and were stimulated for 3 days. Expression of neurotrophic/growth factors, Akt and Erk was investigated by Western blotting analysis 3 days after repetitive magnetic stimulation. Neuroblastoma cell proliferation was determined with a cell counting assay. There were differences in cell proliferation based on stimulus frequency. Low-frequency stimulation did not alter proliferation relative to the control, while high-frequency stimulation elevated proliferation relative to the control group. The expression levels of brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), neurotrophin-3 (NT-3) and platelet-derived growth factor (PDGF) were elevated in the high-frequency magnetic stimulation group. Akt and Erk expression was also significantly elevated in the high-frequency stimulation group, while low-frequency stimulation decreased the expression of Akt and Erk compared to the control. In conclusion, we determined that different frequency magnetic stimulation had an influence on neuronal cell proliferation via regulation of Akt and ERK signaling pathways and the expression of growth factors such as BDNF, GDNF, NT-3 and PDGF. These findings represent a promising opportunity to gain insight into how different frequencies of repetitive magnetic stimulation may mediate cell proliferation.
authors.affiliation: Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Ji Yong
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Department of Rehabilitation Medicine, The Graduate School Yonsei University Wonju College of Medicine, South Korea.
authors.forename: Hyung Joong
authors.initials: HJ
authors.lastname: Park
authors.affiliation: Department of Rehabilitation Medicine, Yonsei University Wonju College of Medicine, Wonju, South Korea.
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Anatomy, Yonsei University Wonju College of Medicine, Wonju, South Korea; Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, South Korea.
authors.forename: Byung Pil
authors.initials: BP
authors.lastname: Cho
authors.affiliation: Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea; Brain Korea 21 PLUS Project for Medical Science and Rehabilitation Institute of Neuromuscular Disease, Yonsei University College of Medicine, Seoul, Korea. Electronic address: srcho918@yuhs.ac.
authors.forename: Sung-Rae
authors.initials: SR
authors.lastname: Cho
authors.affiliation: Department of Rehabilitation Medicine, Yonsei University Wonju College of Medicine, Wonju, South Korea. Electronic address: kimrehab@yonsei.ac.kr.
authors.forename: Sung Hoon
authors.initials: SH
authors.lastname: Kim
mesh_terms: D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D051379:Mice; D009414:Nerve Growth Factors / Q000378:metabolism; D009474:Neurons / Q000166:cytology* / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D050781:Transcranial Magnetic Stimulation
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D051100:Glial Cell Line-Derived Neurotrophic Factor; D036341:Intercellular Signaling Peptides and Proteins; D009414:Nerve Growth Factors; D010982:Platelet-Derived Growth Factor; C518911:neurotropin 3, mouse; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases
keywords: Cell proliferation; Neuron; Neurotrophic/growth factor; Repetitive magnetic stimulation