“Latest Stem Cells News”

Researchers said on Sunday they had found a safer way to transform ordinary skin cells into powerful stem cells in a move that could eventually remove the need to use human embryos.
It is the first time that scientists have turned skin cells into induced pluripotent stem cells or iPS cells — which look and act like embryonic stem cells — without having to use viruses in the process.
The new method also allows for genes that are inserted to trigger cell reprogramming to be removed afterwards.
Stem cells are the body’s master cells, producing all the body’s tissues and organs.

Embryonic stem cells are the most powerful kind, as they have the potential to give rise to any tissue type. However, many people object to their use, making iPS cells an attractive alternative, provided they can be made safely.
Researchers have known for some time that ordinary skin cells can be transformed into iPS cells using a handful of genes.
But to get these genes into the cells they have had to use viruses, which integrate their own genetic material into the cells they infect. This can cause cancer.

The alternative approach, described in the online edition of the journal Nature by two teams of researchers from Britain and Canada, appears to avoid the risk of such abnormalities.
The researchers harnessed a little piece of DNA called a transposon — sometimes known as a “jumping gene” because of its ability to move around inside the genetic code — to carry four genes.

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Each one of us receives approximately 60 new mutations in our genome from our parents.

This striking value is reported in the first-ever direct measure of new mutations coming from mother and father in whole human genomes published today.

For the first time, researchers have been able to answer the questions: how many new mutations does a child have and did most of them come from mum or dad? The researchers measured directly the numbers of mutations in two families, using whole genome sequences from the 1000 Genomes Project. The results also reveal that human genomes, like all genomes, are changed by the forces of mutation: our DNA is altered by differences in its code from that of our parents. Mutations that occur in sperm or egg cells will be ‘new’ mutations not seen in our parents.

Although most of our variety comes from reshuffling of genes from our parents, new mutations are the ultimate source from which new variation is drawn. Finding new mutations is extremely technically challenging as, on average, only 1 in every 100 million letters of DNA is altered each generation.

Previous measures of the mutation rate in humans has either averaged across both sexes or measured over several generations. There has been no measure of the new mutations passed from a specific parent to a child among multiple individuals or families.

Researchers at Johns Hopkins have found a better way to create induced pluripotent stem (iPS) cells—adult cells reprogrammed with the properties of embryonic stem cells—from a small blood sample. This new method, described last week in Cell Research, avoids creating DNA changes that could lead to tumor formation.

“These iPS cells are much safer than ones made with previous technologies because they don’t involve integrating foreign viruses that can potentially lead to uncontrolled, cancerous cell growth,” says Linzhao Cheng, Ph.D., an associate professor of medicine in the Division of Hematology and a member of the Johns Hopkins Institute of Cell Engineering. “This is important if iPS cells are to be used as therapies one day.”

Cheng says the higher-quality iPS cells will also be more reliable in research studies, “since we don’t have to worry about extra genetic changes associated with previous technologies interfering with study results.”

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Steven Goldman, M.D., Ph.D.

Scientists have created a way to isolate neural stem cells – cells that give rise to all the cell types of the brain – from human brain tissue with unprecedented precision, an important step toward developing new treatments for conditions of the nervous system, like Parkinson’s and Huntington’s diseases and spinal cord injury.

The work by a team of neuroscientists at the University of Rochester Medical Center was published in the Nov. 3 issue of the Journal of Neuroscience. Neurologist Steven Goldman, M.D., Ph.D., chair of the Department of Neurology, led the team.

The latest paper marks a six-year effort by Goldman’s team to develop a better way to isolate pure preparations of neural stem cells directly from the human brain. These stem cells can renew themselves and have the potential to become a number of brain cell types – for instance, oligodendrocytes that might help people with multiple sclerosis, or neurons to help people with Parkinson’s disease. But after the first few months of human embryonic development, they become rare in the brain, and it’s challenging for scientists to find, isolate and manipulate them. Yet those challenges must be met if stem cells are to live up to their promise as treatments for a host of human diseases of the nervous system.

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Cells from people with premature aging disease get “younger” with the help of stem cell technology.

Premature aging is one of the most difficult-to-deal with conditions in the world. In addition to its physical consequences, its psychological impact is devastating on a person suffering from it. At this point, experts believe that the disease is caused by the fact that people predisposed to it have very short telomeres, which are repetitive stretches of DNA attached to the end of each chromosome in each cell featuring genetic material in the human body. As chromosomes multiply, the telomeres naturally get shorter, and scientists believe that this may be playing a role in aging.

UC San Diego scientists have dramatically improved the success rate of genetically modifying human embryonic stem cells. This advance brings the promise of better treatment of genetic diseases.
The new approach works in 20 percent of embryonic stem cells, compared to less than 1 percent treated with standard methods, said Yang Xu, a UCSD professor of biology, who led the study, assisted by Hoseok Song and Sun-Ku Chung, postdoctoral fellows in his lab.

The study was published Thursday in the journal Cell Stem Cell.
Some genetic diseases can’t be studied adequately in animals, Xu said, so the ability to produce human cells with the diseases will be of great help. For example, drugs to treat the diseases can be tested in the genetically modified cells, he said.