In Brief The human body is a melding of different systems designed to function well together. In some cases, however, a mechanism that protects the body can also cause it harm, like with the specializedshield of endothelial cells called the blood-brain barrier that keeps toxins in the blood from entering the brain. Due to a genetic defect, the blood-brain barrier could prevent essential biomolecules needed for normal brain development from passing through. An example is the Allan-Herndon-Dudley syndrome (AHDS), which is a psychomotor disease resulting from a defective gene that controls the influx of thyroid hormones to the brain. This rare but severe disorder is also unique to humans, making it very difficult to develop treatments that could be lab tested on animals. So, to study this unique disorder, scientists from the University of Wisconsin-Madison and Cedars-Sinai in Los Angeles used the cells of AHDS patients to recreate the patients blood-brain barriers via induced pluripotent steam (iPS) cellstechnology. What they learned using the model gave the researchers some leads on potential therapies for the disease. They published their study in the journal Cell Stem Cell. The researchers managed to make a laboratory model for AHDS. This is the first demonstration … Continue reading →

Rio Sugimura Researchers made these blood stem cells and progenitor cells from human induced pluripotent stem cells. After 20 years of trying, scientists have transformed mature cells into primordial blood cells that regenerate themselves and the components of blood. The work, described today in Nature1, 2, offers hope to people with leukaemia and other blood disorders who need bone-marrow transplants but cant find a compatible donor. If the findings translate into the clinic, these patients could receive lab-grown versions of their own healthy cells. One team, led by stem-cell biologist George Daley of Boston Childrens Hospital in Massachusetts, created human cells that act like blood stem cells, although they are not identical to those found in nature1. A second team, led by stem-cell biologist Shahin Rafii of Weill Cornell Medical College in New York City, turned mature cells from mice into fully fledged blood stem cells2. For many years, people have figured out parts of this recipe, but theyve never quite gotten there, says Mick Bhatia, a stem-cell researcher at McMaster University in Hamilton, Canada, who was not involved with either study. This is the first time researchers have checked all the boxes and made blood stem cells. Daleys team … Continue reading →

Cancer stem cells are bad actors. They enable cancers to metastasize, or spread, and help revive cancers after the malignancies go dormant. One of the few agents that can effectively attack them is a small molecule called salinomycin. But scientists havent understood how the compound kills the cells. Now, researchers have discovered salinomycins mechanism (Nat. Chem. 2017, DOI: 10.1038/nchem.2778). The findings reveal a key weakness of cancer stem cells that could lead to the design of other drugs to help fight the cells. To discover the mechanism, Raphal Rodriguez of Institut Curie and Frances National Center for Scientific Research, Maryam Mehrpour of Institut Necker Enfants Malades and INSERM, and coworkers first tried to create a more potent version of salinomycin by modifying it with groups of varying polarity and charge. The most potent was ironomycin, in which one of salinomycins hydroxyl groups was replaced by a short amine-alkyne chain. Ironomycin has an order of magnitude greater potency than salinomycin at killing breast cancer stem cells, both in culture and in mice. They then used in vivo click chemistry on ironomycins alkyne group to label the compound with a fluorescent dye, enabling them to track where the compound goes when in … Continue reading →