Scientists have found a set of “master switches” that keep adult blood-forming stem cells in their primitive state. Unlocking the switches’ code may one day enable scientists to grow new blood cells for transplant into patients with cancer and other bone marrow disorders. The scientists located the control switches not at the gene level, but farther down the protein production line in more recently discovered forms of ribonucleic acid, or RNA. MicroRNA molecules, once thought to be cellular junk, are now known to swit... lire la suite
Scientists have found a set of “master switches” that keep adult blood-forming stem cells in their primitive state. Unlocking the switches’ code may one day enable scientists to grow new blood cells for transplant into patients with cancer and other bone marrow disorders. The scientists located the control switches not at the gene level, but farther down the protein production line in more recently discovered forms of ribonucleic acid, or RNA.
For cells that hold so much promise, stem cells’ potential has so far gone largely untapped. But new research from Rockefeller University and Howard Hughes Medical Institute scientists now shows that adult stem cells taken from skin can be used to clone mice using a procedure called nuclear transfer.
In the rancorous public debate over federal research funding, stem cells are generally assigned to one of two categories: embryonic or adult. But that’s a false dichotomy and an oversimplification. A new University of Michigan study adds to mounting evidence that stem cells in the developing fetus are distinct from both embryonic and adult stem cells.
Researchers at the University of Pennsylvania School of Veterinary Medicine have derived uniparental embryonic stem cells - created from a single donor’s eggs or two sperm - and, for the first time, successfully used them to repopulate a damaged organ with healthy cells in adult mice. Their findings demonstrate that single-parent stem cells can proliferate normally in an adult organ and could provide a less controversial alternative to the therapeutic cloning of embryonic stem cells.
For many years, researchers believed that stem cells in the bone marrow spent most of their existence in a slumber-like state, unaware of — and unaffected by — the daily battles fought by the body's immune system. Not so. Scientists at the Oklahoma Medical Research Foundation have discovered that marrow stem cells — undifferentiated cells that eventually give rise to the blood cells that fight infection — possess receptors that recognize bacteria and viruses.
Stem cells grew, multiplied and differentiated into brain cells on a new three-dimensional scaffold of tiny protein fragments designed to be more like a living body than any other cell culture system. An MIT engineer and Italian colleagues will report the invention-which may one day replace the ubiquitous Petri dish for growing cells-in the Dec.
Scientists at Duke University Medical Center have demonstrated they can grow human stem cells in the laboratory by blocking an enzyme that naturally triggers stem cells to mature and differentiate into specialized cells. The discovery may enable scientists to rapidly grow stem cells and transplant them into patients with blood disorders, immune defects and select genetic diseases, said the Duke researchers.
When stretched, a type of adult stem cell taken from bone marrow can be nudged towards becoming the type of tissue found in blood vessels, according to a new study by bioengineers at the University of California, Berkeley. Researchers placed mesenchymal stem cells onto a silicone membrane that was stretched longitudinally once every second.
Just as many scientists had given up the search, researchers have discovered that the pancreas does indeed harbor stem cells with the capacity to generate new insulin-producing beta cells. If the finding made in adult mice holds for humans, the newfound progenitor cells will represent an obvious target for therapeutic regeneration of beta cells in diabetes, the researchers report in the Jan.
Acclaimed stem cell researcher Shinya Yamanaka, MD, PhD, has reported that he and his Kyoto University colleagues have successfully reprogrammed human adult cells to function like pluripotent embryonic stem (ES) cells. Because it circumvents much of the controversy and restrictions regarding generation of ES cells from human embryos, this breakthrough, reported in the journal Cell, should accelerate the pace of stem cell research.
Stem cells with the capacity to form any type of tissue can be created from adult cells without destroying embryos, according to new research that suggests a way of sidestepping ethical controversy over the field. Three separate teams of scientists have used genetic trickery to wind back the biological clock of mature skin cells from mice, to give them the unlimited potential of stem cells that are normally found only in embryos.
Researchers at Children’s Hospital Boston report a new and efficient strategy, using eggs alone, for creating mouse embryonic stem cells that can be transplanted without the risk of rejection because the cells are compatible with the recipient’s immune system. The findings are published online in the journal Science on December 14.
Scientists have discovered a new source of stems cells and have used them to create muscle, bone, fat, blood vessel, nerve and liver cells in the laboratory. The first report showing the isolation of broad potential stem cells from the amniotic fluid that surrounds developing embryos was published in Nature Biotechnology.
Researchers at UCLA today announced they have transformed adult stem cells taken from human adipose – or fat tissue – into smooth muscle cells, which help the normal function of a multitude of organs like the intestine, bladder and arteries. The study may help lead to the use of fat stem cells for smooth muscle tissue engineering and repair.
Researchers from the UCLA AIDS Institute and the Institute for Stem Cell Biology and Medicine have demonstrated for the first time that human embryonic stem cells can be genetically manipulated and coaxed to develop into mature T-cells, raising hopes for a gene therapy to combat AIDS. The study, to be published the week of July 3 in the online edition of the Proceedings of the National Academy of Sciences, found that it is possible to convert human embryonic stem cells into blood-forming stem cells that in turn can differentiate into the helper T-cells that HIV specifically targets.
Filed under: Type 1, Type 2, Childhood, Adult Onset, Research, Care, Complications Diabetic foot complications are responsible for many lower extremity amputations. But this last drastic step can be prevented up to 85 percent of the time with early diagnosis and proper care. Now Thai researchers and physicians have shown using a patient's own stem cells can effectively heal chronic foot wounds.
Researchers at the Joslin Diabetes Center have demonstrated for the first time that transplanted muscle stem cells can both improve muscle function in animals with a form of muscular dystrophy and replenish the stem cell population for use in the repair of future muscle injuries. I’m very excited about this,” said lead author Amy J.
From Massachusetts: Thu Sep 25, 2008 2: pm EDT Researchers have developed a safer way to make powerful stem cells from ordinary skin cells, taking one more step toward so-called regenerative medicine. They used a common cold virus to carry transformative genes into ordinary mouse cells, making them look and act like embryonic stem cells.
A human embryonic stem cell is reined in – prevented from giving up its unique characteristics of self-renewal and pluripotency – by the presence of a protein modification that stifles any genes that would prematurely instruct the cell to develop into heart or other specialized tissue. But, thanks to the simultaneous presence of different protein modifications, stem cells are primed and poised, ready to develop into specialized body tissue, Singapore scientists reported in last month's issue of the journal Cell Stem Cell.
A startling discovery on the development of human embryonic stem cells by scientists at McMaster University will change how future research in the area is done. An article published in the prestigious scientific journal Nature this week reports on a new understanding of the growth of human stem cells.