R449 – The Role of DPZF in Inner Ear Development and Function

Abstract

Problem The dendritic cell-derived BTB/POZ zinc finger (DPZF) protein belongs to the C2H2 zinc finger protein transcription factor family. It is localized on chromosome 3 and widely expressed in hematopoietic tissues, including human dendritic cells (DC), monocytes, B cells and T cells. DPZF null mice (DPZF-/-) exhibit a circling phenotype, suggestive of an inner ear defect. Here, we present our work on the role of DPZF in hearing defects. Methods We used auditory brainstem responses (ABR) and distortion production otoacoustic emissions (DPOAEs) to test the hearing function of DPZF-/- mice, then gross observation and histopathology analysis including serial sections and scanning electron microscopy were performed to exam the cochlea of DPZF-/- mice. Results Auditory brainstem responses (ABR) and distortion production otoacoustic emissions (DPOAEs) showed that DPZF-/-mice were completely deaf. Disorganized and fewer hair cells of the Corti organ in DPZF-/- mice were identified by scanning electron microscopy. Besides, although the hair cells of the utricle and saccule were grossly normal, the stereocilia were greatly reduced in number. Further more, lipofuscin was seen in the stria vascularis with the amount of which increased with age. Conclusion The impaired hearing and balance function and the morphological abnormalities of inner ears are caused by the deletion of DPZF gene. Significance DPZF gene may participates in regulating inner ear development and the DPZF null mice may serve as a new disease model of hearing loss. Support This work was supported by the ground of Jiangsu Province Famous Doctor Project(RC2007010).