title: [Desmoplakin expression silencing affects cardiac voltage-gated sodium channel Nav1.5 in HL-1 cells].
abstract: OBJECTIVE
  To investigate the association of desmoplakin with the distribution and function of Nav1.5 by RNA silencing technology in HL-1 cells.
  
  
  METHODS
  HL-1 cells with desmoplakin expression suppression by RNA silencing were examined for desmoplakin and Nav1.5 protein expressions by Western blotting, and the distribution and co-location of desmoplakin and Nav1.5 protein were detected by immunofluorescence staining. Patch-clamp recording was applied to analyze the changes in whole-cell sodium current after desmoplakin silencing.
  
  
  RESULTS
  Compared with the untreated group and negative control group, the cells with desmoplakin silencing showed obviously reduced expressions of desmoplakin and Nav1.5 proteins. Co-localization of desmoplakin and Nav1.5 was detected at cell-cell contact in untreated and control conditions, and desmoplakin expression silencing induced a drastic redistribution of Nav1.5 with decreased peak current density (156.3∓6.2 vs 41.8∓3.1, n=6, P<0.05), a shift in voltage dependence of steady-state inactivation (-42 mV vs -61 mV, n=5, P<0.05), and prolonged time of recovery from inactivation.
  
  
  CONCLUSIONS
  Desmoplakin silencing caused redistribution of Nav1.5 protein and also changes in its electrophysiological properties in HL-1 cells.
authors.affiliation: Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangzhou, China. ruyuzhang@hotmail.com
authors.forename: Qianhuan
authors.initials: Q
authors.lastname: Zhang
authors.forename: Chunyu
authors.initials: C
authors.lastname: Deng
authors.forename: Fang
authors.initials: F
authors.lastname: Rao
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Liu
authors.forename: Liping
authors.initials: L
authors.lastname: Mai
authors.forename: Jiening
authors.initials: J
authors.lastname: Zhu
authors.forename: Honghong
authors.initials: H
authors.lastname: Tan
authors.forename: Shulin
authors.initials: S
authors.lastname: Wu
mesh_terms: D000818:Animals; D002460:Cell Line; D051180:Desmoplakins / Q000235:genetics* / Q000378:metabolism; D020868:Gene Silencing; D051379:Mice; D009154:Mutation; D032383:Myocytes, Cardiac / Q000378:metabolism*; D062554:NAV1.5 Voltage-Gated Sodium Channel / Q000378:metabolism*
chemical_list: D051180:Desmoplakins; D062554:NAV1.5 Voltage-Gated Sodium Channel; C568321:Scn5a protein, mouse