title: Extensive Supporting Cell Proliferation and Mitotic Hair Cell Generation by In Vivo Genetic Reprogramming in the Neonatal Mouse Cochlea.
abstract: The generation of hair cells (HCs) from the differentiation of proliferating supporting cells (SCs) appears to be an ideal approach for replacing lost HCs in the cochlea and is promising for restoring hearing after damage to the organ of Corti. We show here that extensive proliferation of SCs followed by mitotic HC generation is achieved through a genetic reprogramming process involving the activation of β-catenin to upregulate Wnt signaling, the deletion of Notch1 to downregulate Notch signaling, and the overexpression of Atoh1 in Sox2(+) SCs in neonatal mouse cochleae. We used RNA sequencing to compare the transcripts of the cochleae from control mice and from mice with β-catenin activation, Notch1 deletion, and β-catenin activation combined with Notch1 deletion in Sox2(+) SCs. We identified the genes involved in the proliferation and transdifferentiation process that are either controlled by individual signaling pathways or by the combination of Wnt and Notch signaling. Moreover, the proliferation of SCs induced by Notch1 deletion disappears after deleting β-catenin in Notch1 knock-out Sox2(+) cells, which further demonstrates that Notch signaling is an upstream and negative regulator of Wnt signaling.
  
  
  
  We show here that the extensive proliferation of supporting cells (SCs) and the subsequent mitotic hair cell (HC) generation is achieved through a genetic reprogramming process involving activation of β-catenin to upregulate Wnt signaling, deletion of Notch1 to downregulate Notch signaling, and overexpression of Atoh1 in Sox2(+) SCs in neonatal mice cochleae. By comparing the transcripts of the cochleae among controls, β-catenin activation, Notch1 deletion, and β-catenin activation combined with Notch1 deletion group, we identified multiple genes involved in the proliferation and transdifferentiation process that are either controlled by individual signaling pathways or by the combination of Wnt and Notch signaling. This provides a better understanding of the mechanisms behind mitotic HC generation and might provide new approaches to stimulating mitotic HC regeneration.
authors.affiliation: Otorhinolaryngology Department, Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200031, PR China, Key Laboratory of Hearing Medicine of National Health and Family Planning Commission, Shanghai 200031, PR China.
authors.forename: Wenli
authors.initials: W
authors.lastname: Ni
authors.affiliation: Otorhinolaryngology Department, Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200031, PR China, Key Laboratory of Hearing Medicine of National Health and Family Planning Commission, Shanghai 200031, PR China.
authors.forename: Chen
authors.initials: C
authors.lastname: Lin
authors.affiliation: Otorhinolaryngology Department, Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200031, PR China, Key Laboratory of Hearing Medicine of National Health and Family Planning Commission, Shanghai 200031, PR China, Central Laboratory, Affiliated Eye and ENT Hospital of Fudan University, Shanghai 200031, PR China.
authors.forename: Luo
authors.initials: L
authors.lastname: Guo
authors.affiliation: Otorhinolaryngology Department, Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200031, PR China, Key Laboratory of Hearing Medicine of National Health and Family Planning Commission, Shanghai 200031, PR China.
authors.forename: Jingfang
authors.initials: J
authors.lastname: Wu
authors.affiliation: Otorhinolaryngology Department, Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200031, PR China, Key Laboratory of Hearing Medicine of National Health and Family Planning Commission, Shanghai 200031, PR China, Central Laboratory, Affiliated Eye and ENT Hospital of Fudan University, Shanghai 200031, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing 210096, PR China, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong 226001, PR China, and.
authors.forename: Renjie
authors.identifier: 0000-0002-3885-543X
authors.initials: R
authors.lastname: Chai
authors.affiliation: Otorhinolaryngology Department, Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200031, PR China, Key Laboratory of Hearing Medicine of National Health and Family Planning Commission, Shanghai 200031, PR China, hwli@shmu.edu.cn wenyan_li2000@126.com.
authors.forename: Wenyan
authors.initials: W
authors.lastname: Li
authors.affiliation: Otorhinolaryngology Department, Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200031, PR China, Key Laboratory of Hearing Medicine of National Health and Family Planning Commission, Shanghai 200031, PR China, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, PR China hwli@shmu.edu.cn wenyan_li2000@126.com.
authors.forename: Huawei
authors.initials: H
authors.lastname: Li
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D002453:Cell Cycle / Q000235:genetics / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation / Q000502:physiology*; D003051:Cochlea / Q000166:cytology* / Q000254:growth & development; D005786:Gene Expression Regulation / Q000235:genetics*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006198:Hair Cells, Auditory / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D000081412:Myosin VIIa; D009218:Myosins / Q000235:genetics / Q000378:metabolism; D055495:Neurogenesis / Q000502:physiology*; D010671:Phenylurea Compounds / Q000378:metabolism; D000071656:Receptor, Notch3 / Q000235:genetics / Q000378:metabolism; D055748:SOXB1 Transcription Factors / Q000235:genetics / Q000378:metabolism; D060449:Wnt Signaling Pathway / Q000502:physiology; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D049452:Green Fluorescent Proteins; D000081412:Myosin VIIa; D009218:Myosins; D010671:Phenylurea Compounds; D000071656:Receptor, Notch3; D055748:SOXB1 Transcription Factors; D051176:beta Catenin; C500943:Atoh1 protein, mouse; C000631456:Myo7a protein, mouse; C527783:Sox2 protein, mouse; C032766:ethylene diurea
keywords: Atoh1; Notch; Wnt; hair cells; regeneration; reprogramming