Stem Cells and Their Niches

The document from 2013 explores various studies on stem cells, particularly focusing on their niches and implications in skin and hair follicle biology, as well as their potential therapeutic applications. Key findings include the role of lymphatic endothelial cells in promoting melanoma stem cell renewal, the importance of β1-integrin signaling in maintaining human hair follicle epithelial progenitor cells, and the identification of Lgr5+ and Lgr6+ as major stem cells in the epidermis. It also discusses the impact of hypoxia on stem cell regeneration, the modulation of the extracellular matrix by Lrig1, and the maintenance of cell-cell contacts by miRs-103/107. Additional studies highlighted the alternating states of melanocyte stem cells in hair follicles, the regulation of stem cell differentiation by miR-184 and miR-135b, the hierarchical model of interfollicular epidermis maintenance, and the role of desmoglein3 in hair follicle stem cell niche balance. The document also covers the resistance of REDD1 knockout mice to skin atrophy, gene therapy strategies for epidermolysis bullosa using iPSCs, the importance of cell polarity protein aPKCI, the identification of nail label retaining cells as skin stem cells, the role of Smad proteins and Satb1 in stem cell regulation, the new niche for Merkel cell turnover in the touch dome, and the regulation of hair follicle epithelial progenitor cell survival by cannabinoid receptor 1 signaling.