IN VITRO PROPERTIES OF NEURAL CREST-DERIVED MULTIPOTENT STEM CELLS FROM A BULGE REGION OF WHISKER FOLLICLE

Abstract

71 The neural crest (NC), a transient structure in embryo development, is unique to vertebrates. NC is derived from the ectoderm and formed at the border of neuroectoderm and somatic ectoderm. Originally NC is represented by a cell population lying in the form of epithelial cords emerging from both sides of the neural tube. At the neurulation process end the NC cells undergo an epithelialmesenchymal transition (EMT) and migrate distantly in various tissues and organs of the developing embryo, where they give rise to the multiple differentiated cell types [1, 2]. In adult vertebrate organism the NC derivatives are represented by the following cell types: neurons and glial cells of the peripheral nervous system, the majority of sensory neurons, melanocytes, Merkel cells, odontoblasts, stromal and endothelial cells of cornea, C cells of thyroid gland, the adrenal medulla, a part of thymic stroma [1, 2]. The most plastic are the cells of cranial NC. In addition to the above mentioned differentiated cell types, they form a part of the bone, cartilage and connective tissues of the face, forehead and ventral neck [3, 4]. Unusually wide differentiation potential of the NC cells suggests an existence of multipotent stem cells. Stemple and Anderson firstly revealed the existence of multipotent stem cells in the NC in early embryonic stage of mammalian development [5]. A long time it was thought that, like NC per se, neural crestderived multipotent stem cells (NC-MSCs) have a transient nature. Consequently, the NCMSCs exist only at the premigratory (from the NC specification moment until the beginning of its cell migration) and migratory stages (from the NC cell delamination until their incoming into the sites of final destination), and further, within migration to sites of its final localization, undergo a process of commitment, turning into the progenitor cells with limited proliferative and/or differentiation potential [6, 7]. An example is the transition of NC-MSCs into the melanocyte precursors — melanoblasts. In the last decades, NC-derived cells have been isolated from a number of tissues and organs of the adult mammalians. These cells demonstrate the ability to self-renewal and multilineage differentiation, at least in vitro, i.e., they are multipotent stem cells [8–11]. The origin of these cells from NC was proved by creating special lines of transgenic mice [12, 13], as well as by means of their transplantation in the developing chick embryo, where the NC-MSCs migrated via the UDC 576.3+612.014.2/3