ABSTRACT
Objective To study the temporal and spatial expressions of G protein-coupled receptor, putative receptor protein related to angiotensin type 1 receptor (APJ), in mammal cochlea postnatal development. Methods The cochlear tissues of each group 11 C57BL/ 6 mice at postnatal day 7 (P7), P14, P28 and postnatal month 2(P2M) were taken out under a stereo microscope. Real-time PCR, Western blotting and immunofluorescent staining were used to detect the expressions of APJ in hair cells and spiral ganglion neurons. Results The expression pattern of APJ in cochleae showed an upward trend during the period from P7 to P2M. The temporal expressions of APJ in hair cells and spiral ganglion neurons increased obviously at P14 and P2M. The spatial expression patterns of APJ in hair cells and spiral ganglion neurons followed a declined gradient from base turns to apex turns at P14. Conclusion APJ expression exhibits a specific spatial and temporal pattern during mouse cochlea postnatal development, and may play a role in cochleae maturation and hearing formation.