title: Effect of Growth Factor Supplementation on the Hair Cell Specific Markers of Cells Harvested from Basilar Membrane.
abstract: OBJECTIVE
  Loss of auditory hair cells is a major cause of deafness. The presence of auditory progenitor cells in the inner ear raises the hope for mammalian inner ear cell regeneration. In this study, we aimed to investigate the effect of growth factor supplementations, namely a combination of epidermal growth factor (EGF), insulin-like growth factor (IGF), and beta (β)-fibroblast growth factor (βFGF), on the expression of hair cell-specific markers by cells harvested from the cochlear membrane. This would provide an insight into the capability of these cells to differentiate into hair cells.
  
  
  METHODS
  EGF, IGF, and βFGF were supplemented into the culture medium. The cells were evaluated by morphology, growth kinetic, gene expression, and protein expression.
  
  
  RESULTS
  The cultured cells of mouse basilar membrane were spindle shaped. Growth factors-enriched medium promotes a significantly higher proliferative activity than the basic culture medium but did not alter the cell morphology. Growth factors-enriched medium did not show any significant differences in the protein expression of the hair cell-specific markers myosin VIIa and calretinin and the stem-cell marker nestin. Gene expression analysis showed that the expression of the hair cell-specific genes myosin VIIa and calretinin as well as the stem cell genes nestin, Rex1, and Sox2 was reduced after the cells were passaged in the growth factor-supplemented medium. Cells in the basic medium expressed a significantly higher level of hair cell-specific genes at certain passages.
  
  
  CONCLUSIONS
  Growth factor supplementation could not maintain the expression of hair cell-specific markers by cells obtained from the cochlear membrane.
authors.affiliation: Department of Otorhinolaryngology, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, Malaysia; Tissue Engineering Centre, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, Malaysia. ruszyidrus@gmail.com.
authors.forename: Muhd Azhan
authors.initials: MA
authors.lastname: Ubaidah
authors.forename: Kien Hui
authors.initials: KH
authors.lastname: Chua
authors.forename: Mazita
authors.initials: M
authors.lastname: Ami
authors.forename: Azida
authors.initials: A
authors.lastname: Zainal
authors.forename: Aminuddin
authors.initials: A
authors.lastname: Saim
authors.forename: Lokman
authors.initials: L
authors.lastname: Saim
authors.forename: Yogeswaran
authors.initials: Y
authors.lastname: Lokanathan
authors.forename: Ruszymah Binti
authors.initials: RB
authors.lastname: Haji Idrus
mesh_terms: D000818:Animals; D001489:Basilar Membrane / Q000166:cytology*; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D003470:Culture Media; D006198:Hair Cells, Auditory / Q000166:cytology / Q000378:metabolism*; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins / Q000494:pharmacology*; D051379:Mice
chemical_list: D003470:Culture Media; D036341:Intercellular Signaling Peptides and Proteins