Abstract:

Objective    To investigate the effects of cranial WNT signal pathway combined with DMSO on regeneration of mouse utricle hair cells in vitro. Methods    40 mice were divided into 8 groups randomly. In 1st part: Utricles were treated with 4mmol/L neomycin, then cultured in culture medium with different concentration of Wnt3a (0, 25, 100, 200ng/mL) for 1day. After that, β-catenin, hair cell cilia and nuclei were labeled with immunofluorescence staining. In 2nd part: Utricles were treated with 4mmol/L neomycin, and then cultured in culture medium with 25ng/mL Wnt3a for 6day. After that, utricles were cultured in control and culture medium with 50μmol/L DAPT, 0.1%DMSO, 50μmol/L DAPT+25ng/mL Wnt3a respectively. 10μmol/L Brdu was added in culture medium in every phase in this part. After culturing, Brdu, Myocin7a and nuclei were labeled with immunofluorescence staining. Results    In 1st part, β-catenin was expressed in support cell cytoplasm in 25ng/mL Wnt3a group, but not in 0, 100, 200ng/mL Wnt3a groups. β-catenin positive cells were calculated and compared with other groups. There was significant difference between 25ng/mL Wnt3a group and other groups (0, 100, 200ng/mL)(P<0.01). In 2nd part, Myosin7a positive cells were identified in DMSO group. There was no Myosin7a positive cells but Brdu positive cells in other groups. Myosin7a positive cells were calculated and compared with other groups. There was significant difference between DMSO group and the control, 50μmol/L DAPT, 50μmol/L DAPT+25ng/mL Wnt3a groups(P<0.01). Conclusion    Wnt3a combined with DMSO promotes transdifferentiation to hair celllike cells in utricle by activating cranial WNT signal pathway.

Key words:  Utricle, DMSO, Hair cells, Wnt3a, Regeneration