title: Restricted infection of murine cytomegalovirus (MCMV) in neonatal mice with MCMV-induced sensorineural hearing loss.
abstract: BACKGROUND
  Congenital infection with human Cytomegalovirus (HCMV) is known to be a causative agent of sensorineural hearing loss (SNHL).
  
  
  OBJECTIVE
  To clarify the nongenetic etiology of SNHL by identifying the Cytomegalovirus (CMV)-infected region in the cochleae.
  
  
  METHODS
  We established an animal model of SNHL by injecting neonatal Balb/c mice with intracerebral murine Cytomegalovirus (MCMV) within 24h after delivery.
  
  
  RESULTS
  At 3 weeks of age, unilateral and bilateral SNHL were observed in 24% (5/21) and 29% (6/21) of the mice, respectively. SNHL thereafter progressed, with 79% of mice developing bilateral SNHL by 6 weeks of age. MCMV antigens and DNA were detected in the spiral ganglion, and cells surrounding the meninges and scala tympani at 1 week of age. However, both MCMV antigens and DNA had completely disappeared by 2 weeks of age. It is possible that the MCMV reached the spiral ganglion via cerebrospinal fluid as the result of meningitis, as the stria vascularis was found to be MCMV antigen negative. Myosin VI expression in the outer hair cells was lost at 3 weeks of age. MCMV and myosin VI expression disappeared before and during SNHL progression, respectively.
  
  
  CONCLUSIONS
  There was a definite lag time between the period in which MCMV antigens/DNA-positive cells were observed and that in which SNHL developed and myosin VI-negative hair cells were observed. Further study is needed to explore the role of MCMV in the loss of myosin VI expression in the outer hair cells.
authors.affiliation: Department of Microbiology, Fukushima Medical University School of Medicine, Fukushima, Japan.
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Ikuta
authors.affiliation: Department of Otolaryngology, Fukushima Medical University School of Medicine, Fukushima, Japan; Department of Otolaryngology, Aizu Medical Center, Fukushima Medical University School of Medicine, Fukushima, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ogawa
authors.affiliation: Department of Microbiology, Fukushima Medical University School of Medicine, Fukushima, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Hashimoto
authors.affiliation: Department of Otolaryngology, Fukushima Medical University School of Medicine, Fukushima, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Okano
authors.affiliation: Department of Otolaryngology, Fukushima Medical University School of Medicine, Fukushima, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Tani
authors.affiliation: Department of Otolaryngology, Fukushima Medical University School of Medicine, Fukushima, Japan.
authors.forename: Etsuko
authors.initials: E
authors.lastname: Sato
authors.affiliation: Department of Pathology II, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Kosugi
authors.affiliation: Department of Microbiology, Fukushima Medical University School of Medicine, Fukushima, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Department of Otolaryngology, Fukushima Medical University School of Medicine, Fukushima, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Omori
authors.affiliation: Department of Microbiology, Fukushima Medical University School of Medicine, Fukushima, Japan.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Suzutani
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000956:Antigens, Viral / Q000378:metabolism; D003051:Cochlea / Q000276:immunology / Q000503:physiopathology / Q000821:virology*; D003587:Cytomegalovirus / Q000235:genetics / Q000276:immunology; D003586:Cytomegalovirus Infections / Q000151:congenital* / Q000503:physiopathology* / Q000821:virology; D004279:DNA, Viral / Q000032:analysis; D004195:Disease Models, Animal; D016057:Evoked Potentials, Auditory, Brain Stem; D018072:Hair Cells, Auditory, Outer / Q000378:metabolism; D006319:Hearing Loss, Sensorineural / Q000503:physiopathology / Q000821:virology*; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D018995:Myosin Heavy Chains / Q000378:metabolism
chemical_list: D000956:Antigens, Viral; D004279:DNA, Viral; C089785:myosin VI; D018995:Myosin Heavy Chains
keywords: Animal model; Cytomegalovirus; Hearing loss