Scientists have found that the DNA of human embryonic stem cells is chemically modified in a characteristic, predictable pattern. This pattern distinguishes human embryonic stem cells from normal adult cells and cell lines, including cancer cells. The study, which appears online today in Genome Research, should help researchers understand how epigenetic factors contribute to self-renewal and developmental pluripotence, unique characteristics of human embryonic stem cells that may one day allow them to be used to replace dise... lire la suite
Scientists have found that the DNA of human embryonic stem cells is chemically modified in a characteristic, predictable pattern. This pattern distinguishes human embryonic stem cells from normal adult cells and cell lines, including cancer cells. The study, which appears online today in Genome Research, should help researchers understand how epigenetic factors contribute to self-renewal and developmental pluripotence, unique characteristics of human embryonic stem cells that may one day allow them to be used to replace diseased or damaged cells with healthy ones in a process called therapeutic cloning.
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.
Scientists have developed a new procedure for the differentiation of human embryonic stem cells, with which they have created the first transplantable source of lung epithelial cells. The method involves the use of protein markers under the control of cell-specific promoters to convert undifferentiated human embryonic stem cells into highly-specialized cells.
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.
Scientists reported for the first time that hemangioblast precursor cells derived from human embryonic stem (hES) cells can be used to achieve vascular repair. The research, which appears today online (ahead of print) in the journal Nature Methods, by Advanced Cell Technology (ACT) and its collaborators, describes an efficient method for generating large numbers of bipotential progenitors–known as hemangioblasts–from hES cells that are capable of differentiating into blood vessels, as well as into all blood and immune cell lineages.
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 from International Stem Cell (ISC) Corp. derived four unique embryonic stem cell lines that open the door for the creation of therapeutic cells that will not provoke an immune reaction in large segments of the population. The stem cell lines are “HLA-homozygous,” meaning that they have a simple genetic profile in the critical areas of the DNA that code for immune rejection.
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.
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.
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.
Some of the most challenging obstacles limiting the reprogramming of mature human cells into stem cells may not seem quite as daunting in the near future. Two independent research papers, published by Cell Press in the September 11th issue of the journal Cell Stem Cell, describe new tools that provide invaluable platforms for elucidating the molecular, genetic, and biochemical mechanisms associated with reprogramming.
Scientists have identified about two dozen genes that control embryonic stem cell fate. The genes may either prod or restrain stem cells from drifting into a kind of limbo, they suspect. The limbo lies between the embryonic stage and fully differentiated, or specialized, cells, such as bone, muscle or fat.
A newly discovered small molecule called IQ-1 plays a key role in preventing embryonic stem cells from differentiating into one or more specific cell types, allowing them to instead continue growing and dividing indefinitely, according to research performed by a team of scientists who have recently joined the stem-cell research efforts at the Keck School of Medicine of the University of Southern California.
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.
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.
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.
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.
Researchers from Biotech Research & Innovation Centre (BRIC) at University of Copenhagen have identified a new group of proteins that regulate the function of stem cells. The results are published in the new issue of Cell. All living organisms, including human beings, consist of a number of specialised cell types that all originate from the same type of primal cell;
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.