In vitro long-term development of cultured inner ear stem cells of newborn rat.
The adult mammalian auditory receptor lacks any ability to repair and/or regenerate after injury. However, the late developing cochlea still contains some stem-cell-like elements that might be used to regenerate damaged neurons and/or cells of the organ of Corti. Before their use in any application, stem cell numbers need to be amplified because they are usually rare in late developing and adult tissues. The numerous re-explant cultures required for the progressive amplification process can result in a spontaneous differentiation process. This aspect has been implicated in the tumorigenicity of stem cells when transplanted into a tissue. The aim of this study has been to determine whether cochlear stem cells can proliferate and differentiate spontaneously in long-term cultures without the addition of any factor that might influence these processes. Cochlear stem cells, which express nestin protein, were cultured in monolayers and fed with DMEM containing 5% FBS. They quickly organized themselves into typical spheres exhibiting a high proliferation rate, self-renewal property, and differentiation ability. Secondary cultures of these stem cell spheres spontaneously differentiated into neuroectodermal-like cells. The expression of nestin, glial-fibrillary-acidic protein, vimentin, and neurofilaments was evaluated to identify early differentiation. Nestin expression appeared in primary and secondary cultures. Other markers were also identified in differentiating cells. Further research might demonstrate the spontaneous differentiation of cochlear stem cells and their teratogenic probability when they are used for transplantation.
Carricondo
Francisco
F
Department of Ophtalmology and Otorhinolaryngology, Faculty of Medicine, Complutense University of Madrid, Apartado de Correos 60.075, 28080 Madrid, Spain.
Iglesias
Mari Cruz
MC
Rodríguez
Fernando
F
Poch-Broto
Joaquin
J
Gil-Loyzaga
Pablo
P
D000818:Animals; D000831:Animals, Newborn; D000943:Antigens, Differentiation / Q000096:biosynthesis; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D009925:Organ of Corti / Q000378:metabolism* / Q000473:pathology / Q000637:transplantation; D051381:Rats; D017208:Rats, Wistar; D013234:Stem Cells / Q000378:metabolism* / Q000473:pathology; D013724:Teratoma / Q000378:metabolism / Q000473:pathology
D000943:Antigens, Differentiation