title: Retention of progenitor cell phenotype in otospheres from guinea pig and mouse cochlea.
abstract: BACKGROUND
  Culturing otospheres from dissociated organ of Corti is an appropriate starting point aiming at the development of cell therapy for hair cell loss. Although guinea pigs have been widely used as an excellent experimental model for studying the biology of the inner ear, the mouse cochlea has been more suitable for yielding otospheres in vitro. The aim of this study was to compare conditions and outcomes of otosphere suspension cultures from dissociated organ of Corti of either mouse or guinea pig at postnatal day three (P3), and to evaluate the guinea pig as a potential cochlea donor for preclinical cell therapy.
  
  
  METHODS
  Organs of Corti were surgically isolated from P3 guinea pig or mouse cochlea, dissociated and cultivated under non-adherent conditions. Cultures were maintained in serum-free DMEM:F12 medium, supplemented with epidermal growth factor (EGF) plus either basic fibroblast growth factor (bFGF) or transforming growth factor alpha (TGFα). Immunofluorescence assays were conducted for phenotype characterization.
  
  
  RESULTS
  The TGFα group presented a number of spheres significantly higher than the bFGF group. Although mouse cultures yielded more cells per sphere than guinea pig cultures, sox2 and nestin distributed similarly in otosphere cells from both organisms. We present evidence that otospheres retain properties of inner ear progenitor cells such as self-renewal, proliferation, and differentiation into hair cells or supporting cells.
  
  
  CONCLUSIONS
  Dissociated guinea pig cochlea produced otospheres in vitro, expressing sox2 and nestin similarly to mouse otospheres. Our data is supporting evidence for the presence of inner ear progenitor cells in the postnatal guinea pig. However, there is limited viability for these cells in neonatal guinea pig cochlea when compared to the differentiation potential observed for the mouse organ of Corti at the same developmental stage.
authors.affiliation: Department of Otolaryngology, Medical School, University of São Paulo, São Paulo, Brasil. jeanneoiticica@bioear.com.br
authors.forename: Jeanne
authors.initials: J
authors.lastname: Oiticica
authors.forename: Luiz Carlos M
authors.initials: LC
authors.lastname: Barboza-Junior
authors.forename: Ana Carla
authors.initials: AC
authors.lastname: Batissoco
authors.forename: Karina
authors.initials: K
authors.lastname: Lezirovitz
authors.forename: Regina C
authors.initials: RC
authors.lastname: Mingroni-Netto
authors.forename: Luciana A
authors.initials: LA
authors.lastname: Haddad
authors.forename: Ricardo F
authors.initials: RF
authors.lastname: Bento
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D048429:Cell Size; D002478:Cells, Cultured; D005455:Fluorescent Antibody Technique; D006168:Guinea Pigs; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D009925:Organ of Corti / Q000166:cytology* / Q000187:drug effects; D010641:Phenotype; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects; D016211:Transforming Growth Factor alpha / Q000494:pharmacology
chemical_list: D016211:Transforming Growth Factor alpha