Generation of Inner Ear Cells

Abstract

Methods for generating cells of the inner ear, e.g., hair cells and supporting cells, from stem cells, e.g., mesenchymal stem cells, are provided, as well as compositions including the inner ear cells. Methods for the therapeutic use of the inner ear cells for the treatment of hearing loss are also described.

What is claimed is: 
     
         1 . A method of generating a differentiated inner ear cell, the method comprising:
 contacting a progenitor cell that expresses one or more of nestin, sox2, musashih, or Pax2, with a gamma secretase inhibitor in an amount and for a time sufficient to induce the progenitor cell to express one or more of atonal homolog 1 (Atoh1), jagged 2, p27 Kip , myosin VIIa, or espin, thereby producing a differentiated inner ear cell.   
     
     
         2 . The method of  claim 1 , wherein the progenitor cell is obtained by a method comprising:
 providing a mesenchymal_stem cell; and   culturing the mesenchymal stem cell under conditions sufficient to induce the stem cell to differentiate into the progenitor cell.   
     
     
         3 . The method of  claim 2 , wherein the mesenchymal stem cell is obtained from a subject who has sensorineural hair cell loss. 
     
     
         4 . The method of  claim 2 , wherein culturing the mesenchymal stem cell comprises maintaining the stem cell in medium comprising an epidermal growth factor, a fibroblast growth factor, or an insulin-like growth factor. 
     
     
         5 . The method of  claim 2 , wherein culturing the mesenchymal stem cell comprises maintaining the stem cell in medium comprising neurotrophin-3 or a brain derived neurotrophic factor. 
     
     
         6 . The method of  claim 1 , wherein the gamma secretase inhibitor is an aryl sulfonamide, a dibenzazepine, a benzodiazepine, N-[N-(3,5-difluorophenacetyl)-L-alanyl]-(S)-phenylglycine t-butyl ester (DAPT), L-685,458, or MK0752. 
     
     
         7 . The method of  claim 1 , wherein the differentiated cell is an inner ear auditory hair cell. 
     
     
         8 . The method of  claim 7 , wherein the inner ear auditory hair cell expresses Atoh1, myosin7a, epsin and p 27 Kip. 
     
     
         9 . The method of  claim 1 , wherein the progenitor cell expresses Sox2 and Pax2. 
     
     
         10 . The method of  claim 2 , wherein the progenitor cell expresses Sox2 and Pax2.