title: Pulsed electromagnetic field enhances brain-derived neurotrophic factor expression through L-type voltage-gated calcium channel- and Erk-dependent signaling pathways in neonatal rat dorsal root ganglion neurons.
abstract: Although pulsed electromagnetic field (PEMF) exposure has been reported to promote neuronal differentiation, the mechanism is still unclear. Here, we aimed to examine the effects of PEMF exposure on brain-derived neurotrophic factor (Bdnf) mRNA expression and the correlation between the intracellular free calcium concentration ([Ca(2+)]i) and Bdnf mRNA expression in cultured dorsal root ganglion neurons (DRGNs). Exposure to 50Hz and 1mT PEMF for 2h increased the level of [Ca(2+)]i and Bdnf mRNA expression, which was found to be mediated by increased [Ca(2+)]i from Ca(2+) influx through L-type voltage-gated calcium channels (VGCCs). However, calcium mobilization was not involved in the increased [Ca(2+)]i and BDNF expression, indicating that calcium influx was one of the key factors responding to PEMF exposure. Moreover, PD098059, an extracellular signal-regulated kinase (Erk) inhibitor, strongly inhibited PEMF-dependant Erk1/2 activation and BDNF expression, indicating that Erk activation is required for PEMF-induced upregulation of BDNF expression. These findings indicated that PEMF exposure increased BDNF expression in DRGNs by activating Ca(2+)- and Erk-dependent signaling pathways.
authors.affiliation: Second Clinical Medical College, Southern Medical University, Guangzhou 510280, PR China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Orthopaedics, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, PR China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Yan
authors.affiliation: Department of Clinical Aerospace Medicine, Fourth Military Medical University, Xi'an 710032, PR China.
authors.forename: Juanfang
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Geriatrics, Shaanxi Provincial TCM Hospital, Xi'an 710032, PR China.
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Endocrinology, Shaanxi Provincial TCM Hospital, Xi'an 710032, PR China.
authors.forename: Xinghua
authors.initials: X
authors.lastname: Hu
authors.affiliation: Department of Orthopaedics, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, PR China. Electronic address: sunhhi@163.com.
authors.forename: Honghui
authors.initials: H
authors.lastname: Sun
authors.affiliation: Second Clinical Medical College, Southern Medical University, Guangzhou 510280, PR China. Electronic address: tianjing_ortho@163.com.
authors.forename: Jing
authors.initials: J
authors.lastname: Tian
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001483:Base Sequence; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism*; D020746:Calcium Channels, L-Type; D017931:DNA Primers; D004574:Electromagnetic Fields; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D005727:Ganglia, Spinal / Q000166:cytology / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D020746:Calcium Channels, L-Type; D017931:DNA Primers; D048049:Extracellular Signal-Regulated MAP Kinases
keywords: Brain-derived neurotrophic factor; Calcium; Dorsal root ganglion neurons; Electromagnetic field; Erk inhibitor