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Updated: Mar 29, 2026
Initiating Differentiation in Immortalized Multipotent Otic Progenitor Cells
Published on: January 2, 2016
Cell cycle reactivation of cochlear progenitor cells in neonatal FUCCI mice by a GSK3 small molecule inhibitor
M Roccio1, S Hahnewald1, M Perny1,2
1Laboratory of Inner Ear Research, Department of Clinical Research, University of Bern and University Department of Otorhinolaryngology, Head &Neck Surgery, Inselspital, Bern, Switzerland.
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.
Insights
Researchers identified methods to regenerate auditory hair cells, crucial for hearing. Using specific compounds and transgenic mice, they stimulated stem cell activity in the auditory epithelium, offering potential therapeutic strategies for hearing loss.
Area of Science:
- Oto-regenerative medicine
- Auditory stem cell biology
- Mammalian hearing research
Background:
- Mammalian auditory hair cell loss leads to irreversible hearing deficits due to limited regeneration.
- Tissue-resident stem/progenitor cells in the auditory epithelium offer therapeutic potential.
- Identifying methods to activate these stem cells is key for regenerative strategies.
Purpose of the Study:
- To validate transgenic mouse models (FUCCI, Lgr5-GFP) for studying auditory stem cell regulation.
- To investigate the effect of GSK3 inhibition on auditory supporting cell proliferation and stemness.
- To assess the potential for hair cell regeneration in response to targeted interventions.
Main Methods:
- Utilized FUCCI (Fluorescence Ubiquitization Concentration Imaging) and Lgr5-GFP transgenic mice to track cell cycle and stemness.
- Administered the small molecule CHIR99021 to inhibit Glycogen Synthase Kinase 3 (GSK3).
- Performed whole-mount cultures of the organ of Corti to analyze cell proliferation and differentiation markers (Sox2, MyoVIIa, Edu).
Main Results:
- CHIR99021 treatment significantly increased proliferating sphere-forming cells and Lgr5-GFP+ cells.
- A selective increase in S-G2-M phase cells was observed within the Lgr5-GFP+ population.
- Increased proliferation of Sox2+ supporting cells was detected, with rare appearance of new MyoVIIa+/Edu+ hair cells.
Conclusions:
- Transgenic mouse models (FUCCI, Lgr5-GFP) are effective tools for identifying regulators of auditory organ regeneration.
- GSK3 inhibition promotes auditory supporting cell proliferation, highlighting a potential pathway for regenerative therapies.
- Further research is needed to fully elucidate the contribution of stem cell activity to hair cell regeneration.
