Biology News Net
Stem Cell Research

Category: Stem Cell Research

Researchers at the Johns Hopkins School of Medicine have successfully edited the genome of human- induced pluripotent stem cells, making possible the future development of patient-specific stem cell therapies. Reporting this week in Cell Stem Cell, the team altered a gene responsible for causing the rare blood disease paroxysmal nocturnal hemoglobinuria, or PNH, establishing for the first time a useful system to learn more about the disease.

Scientists have managed to induce cells from pigs to transform into pluripotent stem cells – cells that, like embryonic stem cells, are capable of developing into any type of cell in the body. It is the first time in the world that this has been achieved using somatic cells (cells that are not sperm or egg cells) from any animal with hooves (known as ungulates).

University of Michigan scientists have found that a deficiency in a key tumor suppressor gene in the brain leads to the most common type of adult brain cancer. The study, conducted in mice that mimic human cancer, points the way to more effective future treatments and a way to screen for the disease early.

Driving Miranda, a protein in fruit flies crucial to switch a stem cell's fate, is not as complex as biologists thought, according to University of Oregon biochemists. They've found that one enzyme (aPKC) stands alone and acts as a traffic cop that directs which roads daughter cells will take.

A team from the Institute for Research in Immunology and Cancer (IRIC) at Université de Montréal has succeeded in producing a large quantity of laboratory stem cells from a small number of blood stem cells obtained from bone marrow. The multidisciplinary team, directed by Dr. Guy Sauvageau, thus took a giant step towards the development of a revolutionary treatment based on these stem cells. This worldwide first will advance stem cell research and could have major implications in several fields for which no treatment currently exists.

Stem cells collected from human corneas restore transparency and don't trigger a rejection response when injected into eyes that are scarred and hazy, according to experiments conducted in mice by researchers at the University of Pittsburgh School of Medicine. Their study will be published in the journal Stem Cells and appears online today.

Wanted: stems cells. Just like those absconders chased by police all over the world, everybody can tell about their good deeds but none really knows how to recognize them. Yet, as of today, thanks to a study just published in the Proceedings of the National Accademy of Sciences (PNAS) and authored by Nobel Laureate for Medicine in 2007 Mario Capecchi and by the researcher from the Catholic University of Rome Eugenio Sangiorgi, we now know how to reveal the stem cells camouflaged in the pancreas.

Human embryonic stem cells (hESC) provide a potentially unlimited source of oral mucosal tissues that may revolutionize the treatment of oral diseases. When fully exploited in the future, this source of cells will be able to produce functional tissues to treat a broad variety of oral diseases. However, little is known about how hESC can be developed into complex, multilayer oral tissues that line the gums, cheeks, lips, and other intra-oral sites. However, the use of hES cells for oral application faces numerous obstacles that must be overcome before their therapeutic potential can be realized.

In a genetic engineering breakthrough that could help everyone from bed-ridden patients to elite athletes, a team of American researchers—including 2007 Nobel Prize winner Mario R. Capecchi—have created a "switch" that allows mutations or light signals to be turned on in muscle stem cells to monitor muscle regeneration in a living mammal. For humans, this work could lead to a genetic switch, or drug, that allows people to grow new muscle cells to replace those that are damaged, worn out, or not working for other reasons (e.g., muscular dystrophy). In addition, this same discovery also gives researchers a new tool for the study of difficult-to-treat muscle cancers. The full report containing details of this advance is available online in The FASEB Journal (http://www.fasebj.org).

An experimental procedure that dramatically strengthens stem cells' ability to regenerate damaged tissue could offer new hope to sufferers of muscle-wasting diseases such as myopathy and muscular dystrophy, according to researchers from the University of New South Wales (UNSW).

A Johns Hopkins engineer is trying to coax human stem cells to turn into networks of new blood vessels that could someday be used to replace damaged tissue in people with heart disease, diabetes and other illnesses.

After injuries with blood loss, the body quickly needs to restore the vital blood volume. This is accomplished by a special group of stem cells in the bone marrow. These hematopoietic stem cells remain dormant throughout their lives and are only awakened to activity in case of injury and loss of blood. Then they immediately start dividing to make up for the loss of blood cells. This has recently been shown by a group of scientists headed by Professor Andreas Trumpp of DKFZ.

A research team led by Nancy Speck, PhD, Professor of Cell and Developmental Biology at the University of Pennsylvania School of Medicine, has identified the location and developmental timeline in which a majority of bone marrow stem cells form in the mouse embryo. The findings, appearing online this week in the journal Nature, highlight critical steps in the origin of hematopoietic (or blood) stem cells (HSCs), says senior author Speck, who is also an Investigator with the Abramson Family Cancer Research Institute at Penn.

Scientists have tricked bone marrow into releasing extra adult stem cells into the bloodstream, a technique that they hope could one day be used to repair heart damage or mend a broken bone, in a new study published today in the journal Cell Stem Cell.

Stem cells are the body's primal cells, retaining the youthful ability to develop into more specialized types of cells over many cycles of cell division. How do they do it? Scientists at the Carnegie Institution have identified a gene, named scrawny, that appears to be a key factor in keeping a variety of stem cells in their undifferentiated state. Understanding how stem cells maintain their potency has implications both for our knowledge of basic biology and also for medical applications. The results will be published in the January 9, 2009 print edition of Science.

Investigators from Massachusetts General Hospital (MGH) have found a subpopulation of hematopoietic stem cells, the source of all blood and immune system cells, that reproduce much more slowly than previously anticipated. Use of these cells may improve the outcome of stem cell transplants – also called bone marrow transplants – for the treatment of leukemia and other marrow-based diseases. The report will appear in the journal Nature Biotechnology and is being released online to coincide with a similar study in the journal Cell.

Natural changes in voltage that occur across the membrane of adult human stem cells are a powerful controlling factor in the process by which these stem cells differentiate, according to research published by Tufts University scientists.

One of the most promising new ideas about the causes of cancer, known as the cancer stem-cell model, must be reassessed because it is based largely on evidence from a laboratory test that is surprisingly flawed when applied to some cancers, University of Michigan researchers have concluded.


Liver stem cells expressing FoxL1 (aqua blue) in an injured mouse liver near the bile duct. The FoxL1-containing stem cells are encircled by liver fibroblasts (royal blue), suggestive of a stem cell niche. Credit: Linda Greenbaum, M.D., University of Pennsylvania School of Medicine

Researchers at the Yerkes National Primate Research Center, Emory University, have discovered dental pulp stem cells can stimulate growth and generation of several types of neural cells. Findings from this study, available in the October issue of the journal Stem Cells, suggest dental pulp stem cells show promise for use in cell therapy and regenerative medicine, particularly therapies associated with the central nervous system.

Inside every axon is a dendrite waiting to get out. Hedstrom et al. converted mature axons into dendrites by banishing a protein crucial for neuron development. The results suggest that this transformation could occur after nerve cell damage.

Recent research from the Swedish medical university Karolinska Institutet reveals completely new properties of the skin's stem cells – discoveries that contradict previous findings. The studies, which are published in Nature Genetics, show amongst other things, that hair follicle stem cells can divide actively and transport themselves through the skin tissue.

Scientists from The Forsyth Institute, working with collaborators at Tufts and Tuebingen Universities, have discovered a new control over embryonic stem cells' behavior. The researchers disrupted a natural bioelectrical mechanism within frog embryonic stem cells and trigged a cancer-like response, including increased cell growth, change in cell shape, and invasion of the major body organs. This research shows that electrical signals are a powerful control mechanism that can be used to modulate cell behavior.

Shinya Yamanaka MD, PhD, of Kyoto University and the Gladstone Institute of Cardiovascular Disease (GICD) has taken another step forward in improving the possibilities for the practical application of induced pluripotent stem (iPS) cell technology.

Researchers have identified stem cells with the capacity to build fat, according to a report in the October 17th issue of the journal Cell, a Cell Press publication. Although they have yet to show that the cells can renew themselves, transplants of the progenitor cells isolated from the fat tissue of normal mice can restore normal fat tissue in animals that are otherwise lacking it.

Scientists from The Forsyth Institute, Boston, MA, and the Howard Hughes Medical Institute at the University of Utah School of Medicine have developed a new system in which to study known mammalian adult stem cell disorders. This research, conducted with the flatworm planaria, highlights the genetic similarity between these invertebrates and mammals in the mechanisms by which stem cell regulatory pathways are used during adult tissue maintenance and regeneration. It is expected that this work may help scientists pursue pharmacological, genetic, and physiological approaches to develop potential therapeutic targets that could repair or prevent abnormal stem cell growth which can lead to cancer.

Researchers have shown that immune-defense cells influenced by embryonic stem cell-derived cells can help prevent the rejection of hearts transplanted into mice, all without the use of immunosuppressive drugs.

After years of working toward this goal, scientists at the OU Cancer Institute have found a way to isolate cancer stem cells in tumors so they can target the cells and kill them, keeping cancer from returning.

Mayo Clinic investigators have demonstrated that stem cells can be used to regenerate heart tissue to treat dilated cardiomyopathy, a congenital defect. Publication of the discovery was expedited by the editors of Stem Cells and appeared online in the "express" section of the journal's Web site at http://stemcells.alphamedpress.org/.

Unlike some parents, adult stem cells don't seem to mind when their daughters get a tattoo. In fact, they're willing to pass them along.

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