Báo cáo hóa học: Retention of progenitor cell phenotype in otospheres from guinea pig and mouse cochlea

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Retention of progenitor cell phenotype in otospheres from guinea pig and mouse cochlea
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Báo cáo hóa học: "Retention of progenitor cell phenotype in otospheres from guinea pig and mouse cochlea"Oiticica et al. Journal of Translational Medicine 2010, 8:119http://www.translational-medicine.com/content/8/1/119 RESEARCH Open AccessRetention of progenitor cell phenotype inotospheres from guinea pig and mouse cochleaJeanne Oiticica1*, Luiz Carlos M Barboza-Junior1, Ana Carla Batissoco2, Karina Lezirovitz1,Regina C Mingroni-Netto2, Luciana A Haddad2, Ricardo F Bento1 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 (TGFa). Immunofluorescence assays were conducted for phenotype characterization. Results: The TGFa 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.Introduction to the opposite end of the cell by a synapsis [1]. MostThe sense of hearing, one of the five primary senses, is types of congenital and acquired hearing loss arise frommediated through a complex sensory system that allows damage and irreversible loss of cochlear hair cells orthe perception and reaction to a huge variety of sound their associated neurons[2].stimuli. Hearing makes feasib le individual interaction A remarkable characteristic of highly differentiatedwith the environment and is essential for communica- and specialized mammalian cells, including cochleartion. Typically, the auditory system comprises a highly sensory hair cells, is that after birth they are held in aspecialized sensory epithel ium, the organ of Corti. It post-mitotic state which contributes to their terminalcontains mechanosensory hair cells as the primary trans- differentiation and inability of repair[3]. A complex net-ducers of auditory stimuli, and supporting cells that work of cyclin-dependent kinases and negative cell cycleprovide a structural and physiological supporting epithe- regulators are involved in blocking cell cycle reentry,lium. One end of hair cells interacts with physical inputs progression and differentiation in mammalian inner ear,and transmits these signals to the neural circuits, linked maintaining the cell cycle arrest[4-7]. However, it has been reported that supporting cell proliferation and hair cell regeneration spontaneously occurs in vitro after* Correspondence: jeanneoiticica@bioear.com.br1 Department of Otolaryngology, Medical School, University of São Paulo, São aminoglycoside ototoxicity in the vestibular sensoryPaulo, Brasil ...