Tricellulin Expression and its Deletion Effects in the Endolymphatic Sac

• Published in: The journal of international advanced otology Vol. 14; no. 2; pp. 312 - 316
• Main Authors: Matsubara, Ai, Miyashita, Takenori, Inamoto, Ryuhei, Sakaguchi, Hirofumi, Kamitani, Toru, Mori, Nozomu, Hoshikawa, Hiroshi
• Format: Journal Article
• Language: English
• Published: Turkey AVES 01.08.2018; Mediterranean Society for Otology and Audiology; The European Academy of Otology and Neurotology
• Subjects: Cell junctions; Extracellular fluid; Health aspects; Hearing loss; Junctional complexes (Epithelium); Labyrinth (Ear); Larynx; Lasers; Membrane proteins; Morphology; Original; Permeability; Physiological aspects; Proteins; United States > US
• ISSN: 1308-7649; 2148-3817
• DOI: 10.5152/iao.2018.5473

Tricellulin is a tight junction (TJ)-forming protein that participates in the sealing function of tricellular TJs. Tricellulin-knockout (Tric-/-) mice show progressive hearing loss with degeneration of hair cells in the cochlea without physiological or physical disorders. In the present study, we investigated the tricellulin expression and its deletion effects in the endolymphatic sac (ES) using Tric-/- mice. The ES epithelia from wild-type (WT) mice were laser-microdissected, and RT-PCR was performed. The ES sections from Tric-/- and WT mice were immunostained with an anti-tricellulin antibody. Hematoxylin and eosin staining was performed for morphological examination. The inner ear of Tric-/- mice was perfused with biotinylation reagents, and the ES sections were observed for tracer permeability assay after applying streptavidin-Alexa Fluor 488 conjugate. The tricellulin expression was confirmed by RT-PCR and by immunohistochemistry in the WT ES. The ES in Tric-/- mice showed normal morphology and revealed no biotin leakage from the lumen. The ES in Tric-/- mice showed no changes in morphology or disruption in macromolecular barrier function. The effects of solute leakages in the ES of Tric-/- mice may be very limited and compensatable, or that the ES epithelia may have other sealing system covering the lack of tricellulin.