The connexin 30 A88V mutant reduces cochlear gap junction expression and confers long-term protection against hearing loss.
John J KellyJulia M AbitbolStephanie HulmeEric R PressDale W LairdBrian L AllmanPublished in: Journal of cell science (2019)
Mutations in the genes that encode the gap junction proteins connexin 26 (Cx26, encoded by GJB2) and Cx30 (GJB6) are the leading cause of hereditary hearing loss. That said, the Cx30 p.Ala88Val (A88V) mutant causes Clouston syndrome, but not hearing loss. Here, we report that the Cx30-A88V mutant, despite being toxic to inner ear-derived HEI-OC1 cells, conferred remarkable long-term protection against age-related high frequency hearing loss in Cx30A88V/A88V mice. During early development, there were no overt structural differences in the cochlea between genotypes, including a normal complement of hair cells; however, the supporting cell Cx30 gap junction plaques in mutant mice were reduced in size. In adulthood, Cx30A88V/A88V mutant mice had a reduction of cochlear Cx30 mRNA and protein, yet a full complement of hair cells. Conversely, the age-related high frequency hearing loss in Cx30+/+ and Cx30+/A88V mice was due to extensive loss of outer hair cells. Our data suggest that the Cx30-A88V mutant confers long-term hearing protection and prevention of hair cell death, possibly via a feedback mechanism that leads to the reduction of total Cx30 gap junction expression in the cochlea.
Keyphrases
- hearing loss
- high frequency
- induced apoptosis
- cell cycle arrest
- wild type
- cell death
- transcranial magnetic stimulation
- poor prognosis
- high fat diet induced
- endoplasmic reticulum stress
- type diabetes
- metabolic syndrome
- machine learning
- signaling pathway
- skeletal muscle
- cell proliferation
- depressive symptoms
- adipose tissue
- artificial intelligence
- deep learning
- cell therapy
- amino acid
- genome wide identification