[Model in vivo to study the transdifferentiation of the somatic cell into urothelium].

Development of reconstructive therapy of the urinary tract using pluripotent and somatic stem cells, for example mesenchymal stem cell (MSCs), recently goes through the stage of experimental studies. These studies include investigation of the main functions of MSCs and urothelium lining from inside the organs of the urinary tract. An important role in the regulation of proliferation and differentiation of urothelium belongs to EGF and Wnt-beta-catenin signaling pathways which activity may be accessed by the level of Her-4 and Tcf3,4, accordingly. We found here that MSCs labeled by transgenic green fluorescence protein (GFP) did not produce in vitro Her-4 and Tcf3,4 but activated their production after transfer into cryoinjured bladder of the syngenic mouse. After MSCs transplantation, GFP was detected in the bladder by RT-PCR and was colocalized with Her-4 or Tcf3,4 in a few urothelium cells detected by immunohistichemical staining with specific antibodies. These results suggest that MSCs labeled by GFP may be used as a good model to study transdifferentiation of somatic cells into urothelium.