title: Acanthamoeba migration in an electric field.
abstract: OBJECTIVE
  We investigated the in vitro response of Acanthamoeba trophozoites to electric fields (EFs).
  
  
  METHODS
  Acanthamoeba castellanii were exposed to varying strengths of an EF. During EF exposure, cell migration was monitored using an inverted microscope equipped with a CCD camera and the SimplePCI 5.3 imaging system to capture time-lapse images. The migration of A. castellanii trophozoites was analyzed and quantified with ImageJ software. For analysis of cell migration in a three-dimensional culture system, Acanthamoeba trophozoites were cultured in agar, exposed to an EF, digitally video recorded, and analyzed at various Z focal planes.
  
  
  RESULTS
  Acanthamoeba trophozoites move at random in the absence of an EF, but move directionally in response to an EF. Directedness in the absence of an EF is 0.08 ± 0.01, while in 1200 mV/mm EF, directedness is significantly higher at -0.65 ± 0.01 (P < 0.001). We find that the trophozoite migration response is voltage-dependent, with higher directionality with higher voltage application. Acanthamoeba move directionally in a three-dimensional (3D) agar system as well when exposed to an EF.
  
  
  CONCLUSIONS
  Acanthamoeba trophozoites move directionally in response to an EF in a two-dimensional and 3D culture system. Acanthamoeba trophozoite migration is also voltage-dependent, with increased directionality with increasing voltage. This may provide new treatment modalities for Acanthamoeba keratitis.
authors.affiliation: Department of Dermatology, Institute for Regenerative Cures, School of Medicine, University of California at Davis, Davis, California, USA.
authors.forename: Jolene Chang
authors.initials: JC
authors.lastname: Rudell
authors.forename: Jing
authors.initials: J
authors.lastname: Gao
authors.forename: Yuxin
authors.initials: Y
authors.lastname: Sun
authors.forename: Yaohui
authors.initials: Y
authors.lastname: Sun
authors.forename: James
authors.initials: J
authors.lastname: Chodosh
authors.forename: Ivan
authors.initials: I
authors.lastname: Schwab
authors.forename: Min
authors.initials: M
authors.lastname: Zhao
mesh_terms: D048248:Acanthamoeba castellanii / Q000502:physiology*; D000818:Animals; D004558:Electric Stimulation; D004574:Electromagnetic Fields; D055724:Electrophysiological Phenomena; D053058:Trophozoites / Q000502:physiology; D014741:Video Recording
keywords: Acanthamoeba; directional cell migration; electric fields