Time-controllable Nkcc1 knockdown replicates reversible hearing loss in postnatal mice. Issue 1 (December 2017)

• Record Type: Journal Article
• Authors: Watabe, Takahisa; Xu, Ming; Watanabe, Miho; Nabekura, Junichi; Higuchi, Taiga; Hori, Karin; Sato, Mitsuo; Nin, Fumiaki; Hibino, Hiroshi; Ogawa, Kaoru; Masuda, Masatsugu; Tanaka, Kenji
• Is Part Of: Scientific reports. Volume 7:Issue 1(2017)
• Page Start: 1
• Page End: 11
• Publication Date: 2017-12
• Subjects: Natural history -- Research -- Periodicals; Biology -- Research -- Periodicals; Physical sciences -- Research -- Periodicals; Earth sciences -- Research -- Periodicals; Environmental sciences -- Research -- Periodicals; 502.85
• DOI: 10.1038/s41598-017-13997-7
• Languages: English
• ISSNs: 2045-2322

Abstract

Abstract Identification of the causal effects of specific proteins on recurrent and partially reversible hearing loss has been difficult because of the lack of an animal model that provides reversible gene knockdown. We have developed the transgenic mouse lineActin -tTS::Nkcc1 tetO/tetO for manipulatable expression of the cochlear K+ circulation protein, NKCC1.Nkcc1 transcription was blocked by the binding of a tetracycline-dependent transcriptional silencer to the tetracycline operator sequences inserted upstream of theNkcc1 translation initiation site. Administration of the tetracycline derivative doxycycline reversibly regulatedNkcc1 knockdown. Progeny from pregnant/lactating mothers fed doxycycline-free chow from embryonic day 0 showed strong suppression ofNkcc1 expression (~90% downregulation) andNkcc1 null phenotypes at postnatal day 35 (P35). P35 transgenic mice from mothers fed doxycycline-free chow starting at P0 (delivery) showed weaker suppression ofNkcc1 expression (~70% downregulation) and less hearing loss with mild cochlear structural changes. Treatment of these mice at P35 with doxycycline for 2 weeks reactivatedNkcc1 transcription to control levels and improved hearing level at high frequency; i.e., these doxycycline-treated mice exhibited partially reversible hearing loss. Thus, development of theActin -tTS::Nkcc1 tetO/tetO transgenic mouse line provides a mouse model for the study of variable hearing loss through reversible knockdown ofNkcc1 .