title: Cell cycle reactivation of cochlear progenitor cells in neonatal FUCCI mice by a GSK3 small molecule inhibitor.
abstract: Due to the lack of regenerative capacity of the mammalian auditory epithelium, sensory hair cell loss results in permanent hearing deficit. Nevertheless, a population of tissue resident stem/progenitor cells has been recently described. Identification of methods to trigger their activity could lead to exploitation of their potential therapeutically. Here we validate the use of transgenic mice reporting cell cycle progression (FUCCI), and stemness (Lgr5-GFP), as a valuable tool to identify regulators of cell cycle re-entry of supporting cells within the auditory epithelium. The small molecule compound CHIR99021 was used to inhibit GSK3 activity. This led to a significant increase in the fraction of proliferating sphere-forming cells, labeled by the FUCCI markers and in the percentage of Lgr5-GFP + cells, as well as a selective increase in the fraction of S-G2-M cells in the Lgr5 + population. Using whole mount cultures of the organ of Corti we detected a statistically significant increment in the fraction of proliferating Sox2 supporting cells after CHIR99021 treatment, but only rarely appearance of novel MyoVIIa +/Edu + hair cells. In conclusion, these tools provide a robust mean to identify novel regulators of auditory organ regeneration and to clarify the contribution of stem cell activity.
authors.affiliation: Laboratory of Inner Ear Research, Department of Clinical Research, University of Bern and University Department of Otorhinolaryngology, Head &Neck Surgery, Inselspital, Bern, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Roccio
authors.affiliation: Laboratory of Inner Ear Research, Department of Clinical Research, University of Bern and University Department of Otorhinolaryngology, Head &Neck Surgery, Inselspital, Bern, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Hahnewald
authors.affiliation: Laboratory of Inner Ear Research, Department of Clinical Research, University of Bern and University Department of Otorhinolaryngology, Head &Neck Surgery, Inselspital, Bern, Switzerland.|Laboratory of Neuroinfectiology, Institute of Infectious Diseases (IFIK), University of Bern.
authors.forename: M
authors.initials: M
authors.lastname: Perny
authors.affiliation: Laboratory of Inner Ear Research, Department of Clinical Research, University of Bern and University Department of Otorhinolaryngology, Head &Neck Surgery, Inselspital, Bern, Switzerland.|Department of Otorhinolaryngology, Head &Neck Surgery University Hospital Geneva (HUG), Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Senn
mesh_terms: D000818:Animals; D002453:Cell Cycle / Q000187:drug effects* / Q000235:genetics*; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D003051:Cochlea / Q000166:cytology*; D015870:Gene Expression; D017930:Genes, Reporter; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006198:Hair Cells, Auditory / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D011725:Pyridines / Q000494:pharmacology*; D011743:Pyrimidines / Q000494:pharmacology*; D043562:Receptors, G-Protein-Coupled / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects; D013234:Stem Cells / Q000187:drug effects* / Q000378:metabolism*
chemical_list: C473711:Chir 99021; C493597:Lgr5 protein, mouse; D011725:Pyridines; D011743:Pyrimidines; D043562:Receptors, G-Protein-Coupled; D038362:Glycogen Synthase Kinase 3