Stem cells in Skin Tisular Engineering Sara Guerrero-Aspizua1,2,3, Marcela del Río1,3
Marta
Carretero1,3
and
1. Regenerative Medicine Unit, Epithelial Biomedicine Division, CIEMAT, Madrid, 2. Department of Bioengineering, Universidad Carlos III (UC3M), Madrid, 3. Centro de Investigaciones Biomédicas en Red en Enfermedades Raras (CIBERER), Madrid, Spain.
Introduction The presence of adult stem cells have been described in a lot of tissues and organs, including brain, bone marrow, peripheral blood, blood vessels, skeletal muscle, skin, teeth, heart, gut, liver, ovarian epithelium, and testis. Stem cells usually remain in a quiescent state for long periods of time but in the presence of the needed stimulus they are activated by a normal need for more cells to maintain tissues, or by pathological conditions such as disease or tissue injury. Typically, there is a very small number of stem cells in each tissue, making isolation of large quantities of stem cells difficult. Scientists in many laboratories are trying to find better ways to grow substantial numbers of adult stem cells in cell culture and to manipulate them to generate specific cell types so they can be used to treat damaged tissues. The epidermis is the outermost component of the skin formed mostly by a particular kind of epithelial cells known as keratinocytes. It is morphologically divided into different layers or strata. From the bottom (innermost), these layers are basal, spinous, granular, and cornified cell layer (Fig. 1). Keratinocytes produced in the basal layer, where cell proliferation is confined, move upward to the outer surface in a process named as epidermal differentiation. The stem cell´s niche of the skin is located in the basal layer of the epidermis (Fig. 1) and at the base of hair follicles, and knowledge and maintenance of this compartment is crucial for the study of the skin, in both physiological and pathological conditions. Given the importance of these cells, the study of the skin has been widely developed over the past decades, for the design of future therapeutical cutaneous strategies and for replacement therapies, where its wide use is a direct consequence of its easy access [1], [2], [3]. Current cell culture techniques have optimized in vitro expansion of cells obtained from skin biopsies to be assembled in three-dimensional matrices and engineered skin equivalents amenable to clinical use.
HOT TOPICS IN CELL BIOLOGY - Edited by José Becerra and Leonor Santos-Ruiz
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