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The mammary gland is composed two main cellular subtypes: the basal cells and luminal cells. While luminal cells secrete water and nutriments to produce the milk during lactation, the basal cells, through their contraction, guide the circulation of the milk throughout the ductal tree. Luminal cells can be subdivided into estrogen (ER)/progesterone (PR) positive and negative cells. In this study published in  Cell Reports , Alexandra Van Keymeulen and colleagues generated a new transgenic line-allowing lineage tracing of ER+ luminal cells to investigate luminal cell heterogeneity and identify the origin of ER+ luminal cells and the mechanisms regulating their pubertal expansion and adult maintenance. Surprisingly and in sharp contrast with the common thought, which hypothesized the existence of a population of common progenitors that give rise to ER+ and ER- cells, Alexandra Van Keymeulen and colleagues found that the ER+ lineage is maintained by a lineage restricted ER+ luminal

Hans-Reimer Rodewald, a scientist at the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ) in Heidelberg, and his co-workers wanted to capture the dynamic events in blood cell formation instead of merely taking snapshots. In close collaboration with a research team led by systems biologist Thomas Höfer, the scientists have developed a new technology that enables them to precisely follow the developmental tracks of cells. To this end, they label stem cells with a kind of genetic barcode in order to be able to clearly identify their offspring later. "Genetic barcodes have been developed and applied before, but they were based on methods that can also change cellular properties," Rodewald said. " Our barcodes are different: They can be induced tissue-specifically and directly in the genome of mice -- without influencing the animals' physiological development." The basis of the new technology is the so-called Cre/loxP system that is used t

While it has long been recognized that certain viruses can cause cancer by inserting oncogenes into the host cell DNA, the fact that some bacteria can also cause cancer has been slower to emerge and much harder to prove. While it is now clear that most cases of stomach cancer are linked to chronic infections with  H. pylori , the mechanism remains unknown. Thomas F. Meyer and his colleagues at the Max Planck Institute for Infection Biology in Berlin have spent many years investigating this bacterium and the changes it induces in the cells of the stomach epithelium. In particular, they were puzzled how malignancy could be induced in an environment in which cells are rapidly replaced. They suspected that the answer might lie in the stem cells found at the bottom of the glands that line the inside of the stomach, which continually replace the remaining cells 'from the bottom up' -- and which are the only long-lived cells in the stomach . Michael Sigal, a clinical scientist

Certain genetic changes are known to reduce the ability of an enzyme called TET2 to encourage stem cells to become mature blood cells, which eventually die, in many patients with certain kinds of leukemia, say the authors. The new study found that vitamin C activated TET2 function in mice engineered to be deficient in the enzyme. "We're excited by the prospect that high-dose vitamin C might become a safe treatment for blood diseases caused by TET2-deficient leukemia stem cells, most likely in combination with other targeted therapies," says corresponding study author Benjamin G. Neel, MD, PhD, professor in the Department of Medicine and director of the Perlmutter Cancer Center. Changes in the genetic code (mutations) that reduce TET2 function are found in 10 percent of patients with acute myeloid leukemia (AML), 30 percent of those with a form of pre-leukemia called myelodysplastic syndrome, and in nearly 50 percent of patients with chronic myelomonocytic leukemia

We have known for a while that people with lower levels of ascorbate (vitamin C) are at increased cancer risk, but we haven't fully understood why. Our research provides part of the explanation, at least for the blood-forming system," said Dr. Sean Morrison, the Director of CRI. The metabolism of stem cells has historically been difficult to study because a large number of cells are required for metabolic analysis, while stem cells in each tissue of the body are rare. Techniques developed during the study, which was published in  Nature , have allowed researchers to routinely measure metabolite levels in rare cell populations such as stem cells. The techniques led researchers to discover that every type of blood-forming cell in the bone marrow had distinct metabolic signatures -- taking up and using nutrients in their own individual way. One of the main metabolic features of stem cells is that they soak up unusually high levels of ascorbate. To determine if ascorbate is

"It has always been unclear what intra-cellular mechanism initiates cardiac cell fate from undifferentiated cells," says Alexandre Colas, Ph.D., assistant professor in the Development, Aging and Regeneration Program at SBP and corresponding author on the paper. "These genes are the earliest determinants of cardiac cell fate. This enables us to generate unlimited amounts of bona fide cardiac progenitors for regenerative purposes, disease modeling and drug discovery." The international team, which included researchers from the International Centre for Genetic Engineering and Biotechnology in Italy, University Pierre and Marie Curie in France and the University of Coimbra in Portugal, combined CRISPR-Cas9 gene editing, high-throughput microRNA screening and other techniques to identify the role Id genes play in heart development. In particular, CRISPR played a crucial role, allowing them to knock out all four Id genes. Previous studies had knocked out some of th

Known as "humanized" mice, the animals have been engineered to have a human, rather than a murine, immune system. Researchers have relied upon the animals for decades to study, among other things, the immune response to the transplantation of pancreatic islet cells for diabetes and skin grafts for burn victims. However, the Stanford researchers found that, unlike what would occur in a human patient, the humanized mice are unable to robustly reject the transplantation of genetically mismatched human stem cells. As a result, they can't be used to study the immunosuppressive drugs that patients will likely require after transplant. The researchers conclude that the humanized mouse model is not suitable for studying the human immune response to transplanted stem cells or cells derived from them. "In an ideal situation, these humanized mice would reject foreign stem cells just as a human patient would," said Joseph Wu, MD, PhD , director of Stanford's Ca

The transplantation of neural stem cells could help promote repair of an injured spinal cord, but the interaction between donor cells and the resident cells that are part of the body's immune response to injury is not well understood. Hal Nguyen, Aileen Anderson and colleagues found that mice receiving stem cells derived from donated human brain tissue required depletion of a specific population of immune cells in order to improve the mice's ability to walk along a glass plate. Although the donor cells survived equally when transplanted immediately or 30 days after injury, their location and cell type changed with time. These results suggest that immune cells populating the spinal cord at different time points after injury affect the ability of stem cells to promote functional recovery. for more information visit our product website:  Buy Kamagra Polo Online 

The findings are published in the September issue of the  Journal of Clinical Investigation . "The NSCs retained an intrinsic  human  rate of maturation despite being placed in a traumatic rodent environment," said Paul Lu, PhD, associate professor of neurosciences and lead author of the study. "That's a finding of great importance in planning for human clinical trials." Neural stem cells differentiate into neurons and glia or support cells. Researchers like Lu and colleague, Mark Tuszynski, MD, PhD, professor of neuroscience and director of the UC San Diego Translational Neuroscience Institute, have explored their potential as a sort of patch and remedy for spinal cord injuries, implanting NSCs derived from induced pluripotent stem cells into animal models of spinal cord injuries to repair damage. In previously published animal studies, Lu and Tuszynski have shown NSCs can survive implantation and make new connections, even beginning to restore limited p

A new study led by University of Pennsylvania and Technical University of Dresden scientists has identified an important regulator of this process, a protein called Del-1. Targeting it, the researchers noted, could be an effective way to improve stem cell transplants for both donors and recipients. There may also be ways to modulate levels of Del-1 in patients with certain blood cancers to enhance immune cell production. The findings are reported this week in  The Journal of Clinical Investigation . "Because the hematopoetic stem cell niche is so important for the creation of bone marrow and blood cells and because Del-1 is a soluble protein and is easily manipulated, one can see that it could be a target in many potential applications," said George Hajishengallis, the Thomas W. Evans Centennial Professor in the Department of Microbiology i n Penn's School of Dental Medicine and a senior author on the work. "I think that Del-1 represents a major regulator of t