Evidence for otic adult stem cells in the human postmortem inner ear

Introduction:

Lost sensory hair cells of the adult mammalian auditory epithelium are not replaced, resulting in permanent hearing loss. It is generally accepted that the intrinsic regenerative capacity of the organ of Corti is lost during late embryonic development, when these cells undergo terminal mitosis. In the adult utricular sensory epithelium of mice self-renewing and sphere forming cells giving rise to hair cell-like cells in vitro and in vivo were described. Here we investigated the presence of native stem cells residing in the adult human utricle and organ of Corti.

Methods:

From 44 human body donors, vestibular and auditory sensory organs were extracted and dissociated. The cells were cultured and characterized by immunostaining, scanning electron microscopy and gene expression analysis.

Results:

Isolated cells from vestibular and auditory sensory organs obtained from human postmortem body donation could be kept in culture for up to 6 weeks. Viability of the cells significantly increases with short postmortem intervals ( < 20 hours). The dissociated cells of both inner ear tissues possess the ability to proliferate and to form spheres. The newly generated cells express stem cell and otic progenitor markers like Nestin, Sox2, Pax2 and Pax8. Furthermore, gene expression analyses reveal that the spheres are capable of differentiating towards cells that express supporting cell and early hair cell markers in vitro.

Conclusion:

The potential for self-renewal and sphere formation of postmortem-derived cells indicates the presence of a niche of stem or progenitor cells in the adult human organ of Corti. This may open new avenues for a therapy for the regeneration of hair cells.

Publication History

Publication Date:
23 April 2019 (online)