Expression of advanced glycation end‐product receptors in the cochlea

OBJECTIVES/HYPOTHESIS: Advanced glycation end products (AGE) have recently been implicated in aging changes within different tissues of the body. The role of AGEs and their receptors in the mammalian inner ear is largely unknown. In this study we analyzed for the expression of two AGE receptors, namely RAGE and Ddost (AGE-R1). STUDY DESIGN: Controlled animal study. Controlled animal study. This study confirmed the expression of the AGEs receptors RAGE and Ddost (AGE-R1) both on mRNA and protein level in the cochlea. Furthermore, we were able to localize these two receptors in the organ of Corti (OC). METHODS: Expression of RAGE and Ddost (AGE-R1) receptors in the rat cochlea were analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot. Specific localization of these two AGE receptors was also obtained within the mouse OC using immunohistochemistry. RESULTS: We detected RAGE and Ddost (AGE-R1) at the mRNA and protein level in the OC, spiral ganglion, and stria vascularis. Moreover, RAGE and Ddost (AGE-R1) could specifically be identified within the immature and mature OC. CONCLUSIONS: The AGE receptors RAGE and Ddost (AGE-R1) could be identified within the cochlea. Different expression patterns of these two receptors were observed in the immature and mature inner ear.