title: Role of stromal cell-derived factor-1 expression in the injured mouse auditory nerve.
abstract: OBJECTIVE
  The degeneration of hair cells and spiral ganglion neurons (SGNs) is an important pathologic process in the development of sensorineural hearing loss. In a murine model, predictable and reproducible damage to SGNs occurs through the application of ouabain to the round window. Recent evidence has shown that the chemokine stromal cell-derived factor-1 (SDF-1) is a potent chemoattractant of hematopoietic stem cells (HSCs) and provides trophic support to injured tissues during development and maturation. The hypothesis for the current study is that expression of SDF-1 plays an important role in protecting SGNs and preventing further degeneration in the setting of cochlear injury.
  
  
  METHODS
  Prospective, controlled.
  
  
  METHODS
  Academic research laboratory.
  
  
  METHODS
  Auditory brainstem response (ABR) and the expression of SDF-1 mRNA and protein were examined 1, 3, 7, 14, and 30 days after application of ouabain in 35 adult mice.
  
  
  RESULTS
  Following ouabain application, real-time reverse-transcription polymerase chain reaction for SDF demonstrates increased mRNA expression following ouabain injury in nontransplanted mice. A significant increase in SDF protein expression was also observed using immunolabeling techniques and Western blot analysis.
  
  
  CONCLUSIONS
  SDF-1 expression is increased in the auditory nerve following cochlear injury. Further knowledge about the cochlear microenvironment, including SDF-1, is critical to maximizing HSC engraftment in the injured cochlea and providing a therapeutic option for sensorineural hearing loss.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, Charleston, South Carolina 29425, USA. kilpatri@musc.edu
authors.forename: Lauren A
authors.initials: LA
authors.lastname: Kilpatrick
authors.forename: Juhong
authors.initials: J
authors.lastname: Zhu
authors.forename: Fu-Shing
authors.initials: FS
authors.lastname: Lee
authors.forename: Hainan
authors.initials: H
authors.lastname: Lang
mesh_terms: D000818:Animals; D015153:Blotting, Western; D054377:Chemokine CXCL12 / Q000235:genetics / Q000378:metabolism*; D003056:Cochlear Nerve / Q000293:injuries* / Q000473:pathology; D016001:Confidence Intervals; D004195:Disease Models, Animal; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D005786:Gene Expression Regulation; D006319:Hearing Loss, Sensorineural / Q000378:metabolism* / Q000473:pathology; D007150:Immunohistochemistry; D051379:Mice; D008808:Mice, Inbred CBA; D010042:Ouabain / Q000494:pharmacology; D011897:Random Allocation; D012016:Reference Values; D061285:Vestibulocochlear Nerve Injuries / Q000378:metabolism / Q000473:pathology*
chemical_list: D054377:Chemokine CXCL12; D010042:Ouabain