How Stem Cells Make Skin

How Stem Cells Make Skin
　　Stem cells have a unique p90x dvd ability: when they divide, they can either give rise to more stem cells, or to a variety of specialised cell types. In both mice and humans, a layer of cells at the base of the skin contains stem cells that can develop into the specialised cells in the layers above. Scientists at the European pigment yellow 12 Molecular Biology Laboratory (EMBL) in Monterotondo, in collaboration with colleagues at the Centro de Investigaciones Energéticas, Medioambientales y Tecnologicas (CIEMAT) in Madrid, have discovered two proteins that control when tagheuer and how these stem cells switch to being skin cells.
　　The findings, published online September 13 in Nature Cell Biology, pigment red 2 shed light on the basic mechanisms involved not only in formation of skin, but also on skin cancer and other epithelial cancers.
　　At some point in their lives, the stem cells at the new jordan base of the skin stop proliferating and start differentiating into the cells that form the skin itself. To do so, they must turn off the stem cell programme in their genes and turn on the skin cell programme. Researchers suspected that a family of proteins called C/EBPs might be involved in this process, as they were known to air max 95 regulate it in other types of stem cell, but had so far failed to identify which C/EBP protein controlled the switch in skin. Claus Nerlov and his group at EMBL Monterotondo discovered it was not one protein, but two: C/EBPα and C/EBPβ.
　　The EMBL researchers used genetic engineering techniques to delete the genes that encode C/EBPα and max 90 β specifically in the skin of mouse embryos, and found that without these proteins the skin of the mice did not form properly.
　　"Mice with neither C/EBPα nor nike shox oz β had taut and shiny skin that couldnt keep the water inside their bodies", Nerlov explains, "they lacked many of the proteins that make skin mechanically strong and water tight, and they died of de-hydration shortly after birth".
　　However, a single working copy of either the gene for C/EBPα or the cheap air max gene for C/EBPβ was enough to ensure that skin developed properly. This means that the two proteins normally do the same job in the skins stem cells - an unexpected redundancy, which may have arisen because there are so many stem cells in skin that a tight control on men's watches proliferation is needed to avoid problems like cancer. Or it may simply be a by-product of the fact that these two proteins have different functions in other situations, such as wound healing or repair of sunlight-induced skin damage.
　　One of the hallmarks of epithelial coffee table cancers - which include skin, breast, and oral cancers - is that they have genes turned on which would normally only be expressed in embryonic stem cells, and which may help cancer cells divide indefinitely. Such genes become re-expressed in the skin in the absence of C/EBPs. So, by understanding how C/EBPα and β cysteamine hydrochloride turn off such stem cell programmes, researchers hope to come a step closer to finding ways to fight such cancers.
　　When Nerlov and colleagues looked at how C/EBPα and -β work in the skin, they found that these proteins also paint pigments regulate a number of other molecules that control skin development. Several important pathways known to control skin and hair formation were improperly activated in the mice lacking C/EBPα and -β.
　　"This is a very important discovery", says Nerlov. "It opens carbon-carbon composites up a lot of new areas, because we can see how these proteins control virtually every other molecule known to regulate skin cell differentiation. It seems to be a key piece in the puzzle of how our skin is formed and maintained throughout life."