“Latest Stem Cells News”

The prospect of treating genetic diseases with corrected stem cells grown from patients’ own bodies has moved closer, after the results of a remarkable experiment.

Scientists have successfully reprogrammed skin tissue from people with a rare form of anaemia to create powerful stem cells, while at the same time rectifying the genetic defect that causes the condition.

The corrected stem cells could be grown into blood precursor cells for therapy. As these would carry a patient’s own DNA, except for the mutation responsible for the illness, they could be transplanted without risk of rejection by the body’s immune system.

Though the research team, from Spain and the United States, has yet to use the cells to treat patients, and several important hurdles still remain, the achievement has been hailed as a significant advance for stem cell research.

It suggests that it should eventually be possible to treat many inherited conditions by making disease-free stem cells from their own bodies. (…)

The cells were infected with a genetically modified virus to correct the gene that causes Fanconi anaemia. These were then reprogrammed into an embryo-like state by modifying further genes, to create versatile master cells known as induced pluripotent stem cells (IPS cells). (…)

Chris Mathew, Professor of Molecular Genetics at King’s College London, said: “This is an important development for families with this rare, inherited blood disorder. The patients have low numbers of blood stem cells in their bone marrow, so there are very few target cells to correct by gene therapy.

“The new research shows that it is possible to reprogramme skin cells from these patients into stem cells in which the genetic defect has been corrected. In future it may become possible to transfer the corrected stem cells back into the patient, but much work remains to be done.”

Read full article on Times Online

Incoming search terms:

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.

Incoming search terms:

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.

Incoming search terms:

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.”

Incoming search terms:

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.

Incoming search terms:

Researchers from the Center for Stem Cell Biology and Regenerative Medicine and the Department of Medicine at Thomas Jefferson University claim that a gene shown to play a role in the aging process appears to play a role in the regulation of the differentiation of embryonic stem cells.

In the study, published online in the journal Aging Cell, the researchers identified a protein interaction that controls the silencing of Oct4, a key transcription factor that is critical to ensuring that embryonic stem cells remain pluripotent. The protein, WRNp, is the product of a gene associated with Werner syndrome, an autosomal recessive disorder hallmarked by premature aging. The gene expression in Werner syndrome closely resembles that of normal aging, and as a result, Werner syndrome is an accepted model of aging.

Incoming search terms: