PRODUCTION AND CHARACTERISTICS OF THE GROWTH AND MARKER PROPERTIES OF MESENCHYMAL STEM CELLS OF URINARY BLADDER
Mesenchymal stem cells (MSC) are capable for transdifferentiation into cells of another functional phenotype and are a perspective resourse of recovery therapy. MSC of different tissues differ by differentiation potential and in some cases express tissue-specific markers, which indicates close mesenchymal and parenchymal phenotypes of the same tissue. The homoorgan MSC might possibly be induced more effectively for tissue-specific differentiation and the preferred for cell therapy of diseases of the same organ as compared with widely used cells of the bone marrow origin. By using explants of the urinary bladder tissue, we obtained primary urinary bladder cell cultures of MSC of fetal and mature Balb/c mice (MSC-UBF and MSC-UBM) and characterized their properties in the course of long-term passing in culture. Unlike cells of mature animals, MSC-UBF have the steady capability for growth in vitro, clonogenic activity, and differentiation into adipose and bone cells. MSC-UBF express mesenchymal markers CD29, XD44, CD49f, CD90, and CD105, but not panleukocytic marker CD45, and do not differ by these parameters from the bone marrow MSC. Under normal conditions, MSC-UBF produce such urothelial markers as Ck14 and FOXA1, although their expression level is significantly lower than in the urinary bladder tissue. The hypomethylating reagent 5-azacytidin produces in MSC-UBF the expression of activator of urothelial differentiation PPARγ and of markers of functional urothelium — UP1a, UP1b, UP3a, and UP3b. The obtained data indicate a possibility of epigenetic reprogramming of the urinary bladder MSC into urothelium at their treatment with 5-azacytidin, which can serve a basis for a novel model of cell therapy of urinary bladder diseases.