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. 25 issue of Cell, a publication of Cell Press. One of the most interesting characteristics of these [adult] progenitor cells is that ... lire la suite
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.
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.
In some ways, certain tumors resemble bee colonies, says pathologist Tan Ince. Each cancer cell in the tumor plays a specific role, and just a fraction of the cells serve as “queens,” possessing the unique ability to maintain themselves in an unspecialized state and seed new tumors. These cells can also divide and produce the “worker” cells that form the bulk of the tumor.
Embryonic stem cells, prized for their astonishing ability to apparently transform into any kind of cell in the body, acquire their identities in part by interacting with their surroundings - even when they are outside of the body in a laboratory dish, University of Florida scientists report. Using an animal model of embryonic stem cell development, researchers with UF’s McKnight Brain Institute have begun to answer one of the most fundamental questions in science - how does a batch of immature cells give rise to an organ as extraordinarily complex as the human brain?
For the first time, researchers have enticed transplants of embryonic stem cell-derived motor neurons in the spinal cord to connect with muscles and partially restore function in paralyzed animals. The study suggests that similar techniques may be useful for treating such disorders as spinal cord injury, transverse myelitis, amyotrophic lateral sclerosis (ALS), and spinal muscular atrophy.
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.
Researchers have discovered the small number of cells in pancreatic cancer that are capable of fueling the tumor's growth. The finding is the first identification of cancer stem cells in pancreatic tumors. Cancer stem cells are the small number of cancer cells that replicate to drive tumor growth.
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.
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.
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.
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 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.
A report in the January issue of Cell Metabolism, a publication of Cell Press, provides new evidence explaining how stem cells known as satellite cells contribute to building muscles up in response to exercise. These findings could lead to treatments for reversing or improving the muscle loss that occurs in diseases such as cancer and AIDS as well as in the normal aging process, according to the researchers.
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.
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.
The brain contains stem cells with a surprising capacity for repair, researchers report in recent issue of the journal Cell. The novel insight into the brain’s natural ability to heal might ultimately have clinical implications for the treatment of brain damage, according to the researchers.
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.
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.
Scientists have demonstrated for the first time that embryonic stem (ES) cells cultured in the laboratory can produce sperm with the capacity to produce viable offspring. The research, published in the July issue of Developmental Cell, opens many exciting avenues for future studies, including investigation of mechanisms involved in sperm production and development of new treatment strategies for infertility.
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.