title: Interleukin-6 inhibits voltage-gated sodium channel activity of cultured rat spinal cord neurons.
abstract: OBJECTIVE
  Interleukin-6 (IL-6) is a pleiotropic proinflammatory cytokine that plays a key role in the injuries and diseases of the central nervous system (CNS). A voltage-gated Na+ channel (VGSC) is essential for the excitability and electrical properties of the neurons. However, there is still limited information on the role of IL-6 in voltage-gated sodium channels. Our study aimed to investigate the effects of IL-6 on Na+ currents in cultured spinal-cord neurons.
  
  
  METHODS
  VGSC currents were activated and recorded using whole-cell patch-clamp technique in the cultured rat spinal cord neurons. The effects of IL-6 concentration and exposure duration were examined. To determine whether any change in the number of channels in the plasma membrane can inhibit IL-6 on VGSC currents, we examined the expression of α1A (SCN1α) subunit mRNA level and protein level in the neurons before and after IL-6 induction using real-time polymerase chain reaction.
  
  
  RESULTS
  We verified that IL-6, through a receptor-mediated mechanism, suppressed Na+ currents in a time- and dose-dependent manner, but did not alter the voltage-dependent activation and inactivation. Gp130 was involved in this inhibition. Furthermore, the spike amplitude was also inhibited by IL-6 in the doses that decreased the Na+ currents.
  
  
  CONCLUSIONS
  VGSC currents are significantly inhibited by IL-6. Our findings reveal that the potential neuroprotection of IL-6 may result from the inhibitory effects on VGSC currents.
authors.affiliation: 1 Department of Orthopaedics, The Second Xiangya Hospital of Central South University, Hunan, China.
authors.forename: Xiaoning
authors.initials: X
authors.lastname: Li
authors.affiliation: 2 Department of Medical Microbiology, Immunology & Cell Biology, Simmons Cancer Institute, Southern Illinois University School of Medicine, Springfield, USA.
authors.forename: Weiqiang
authors.initials: W
authors.lastname: Chen
authors.affiliation: 2 Department of Medical Microbiology, Immunology & Cell Biology, Simmons Cancer Institute, Southern Illinois University School of Medicine, Springfield, USA.
authors.forename: Jiangtao
authors.initials: J
authors.lastname: Sheng
authors.affiliation: 2 Department of Medical Microbiology, Immunology & Cell Biology, Simmons Cancer Institute, Southern Illinois University School of Medicine, Springfield, USA.
authors.forename: Deliang
authors.initials: D
authors.lastname: Cao
authors.affiliation: 1 Department of Orthopaedics, The Second Xiangya Hospital of Central South University, Hunan, China.
authors.forename: Wanchun
authors.initials: W
authors.lastname: Wang
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002478:Cells, Cultured; D015850:Interleukin-6 / Q000494:pharmacology*; D062550:NAV1.1 Voltage-Gated Sodium Channel / Q000378:metabolism; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000187:drug effects* / Q000378:metabolism*; D061566:Voltage-Gated Sodium Channels / Q000378:metabolism*
chemical_list: D015850:Interleukin-6; D062550:NAV1.1 Voltage-Gated Sodium Channel; C568250:Scn1a protein, rat; D061566:Voltage-Gated Sodium Channels