SOX2, JAGGED1, β-Catenin, and Vitamin D Receptor Expression Patterns during Early Development and Innervation of the...

Area of Science:

• Developmental biology
• Otolaryngology
• Genetics

Background:

• Sensorineural hearing loss can stem from developmental inner ear abnormalities.
• Understanding congenital hearing loss requires knowledge of inner ear formation signaling pathways.

Purpose of the Study:

• To analyze innervation and expression of SOX2, JAGGED1, beta-catenin (CTNNB1), and vitamin D receptor (VDR) in early human inner ear development.
• To correlate these molecular events with the timing of inner ear innervation.

Main Methods:

• Immunohistochemistry was used to examine human conceptuses aged 5 to 10 weeks post-fertilization.
• Expression patterns of SOX2, JAGGED1, CTNNB1, and VDR were analyzed in prosensory and non-sensory regions.
• Innervation timing in vestibular and cochlear domains was assessed.

Main Results:

• SOX2 and JAGGED1 were expressed in prosensory domains throughout development.
• Innervation of vestibular domains began by 6 weeks, reaching cochlear domains by 7-8 weeks.
• CTNNB1 and VDR showed strong expression in non-sensory epithelium, particularly in the vestibular region, with opposing trends over time.

Conclusions:

• SOX2, JAGGED1, CTNNB1, and VDR are dynamically expressed during human inner ear development.
• Innervation patterns correlate with developmental stages.
• Further research is needed to clarify the interaction between CTNNB1 and VDR in inner ear development.