Posts tagged stem cells
Articles and news from the latest research reports.
Study identifies natural process activating brain’s immune cells that could point way to repairing damaged brain
The brain’s key “breeder” cells, it turns out, do more than that. They secrete substances that boost the numbers and strength of critical brain-based immune cells believed to play a vital role in brain health. This finding adds a new dimension to our understanding of how resident stem cells and stem cell transplants may improve brain function.
Many researchers believe that these cells may be able to regenerate damaged brain tissue by integrating into circuits that have been eroded by neurodegenerative disease or destroyed by injury. But new findings by scientists at the Stanford University School of Medicine suggest that another process, which has not been fully appreciated, could be a part of the equation as well. The findings appear in a study published online Oct. 21 in Nature Neuroscience.
“Transplanting neural stem cells into experimental animals’ brains shows signs of being able to speed recovery from stroke and possibly neurodegenerative disease as well,” said Tony Wyss-Coray, PhD, professor of neurology and neurological sciences in the medical school and senior research scientist at the Veterans Affairs Palo Alto Health Care System. “Why this technique works is far from clear, though, because actually neural stem cells don’t engraft well.”
Yamanaka invented cell time machine
Dr. Shinya Yamanaka invented a time machine.
In the simplest of terms, that’s how he and his colleagues sometimes describe their work. They take full-grown cells from humans and they regress them - they send them back in time, to their earliest, embryonic state - and then they coax them into the future, into totally new types of cells.
Last week, Yamanaka was awarded the Nobel Prize in physiology or medicine for his work creating induced pluripotent stem (IPS) cells - cells that are genetically engineered into blank slates, allowing them to be transformed into any type of cell in the body.
His technique could allow scientists to explore human diseases like they never have before, or help doctors regenerate tissue lost to injury or illness. Using his technology, scientists can now take a skin cell and transform it into a heart cell that will actually beat in a lab dish.
"I was here, at Gladstone, the moment I learned we got human IPS cells," said Yamanaka last month, in an interview from his part-time office at San Francisco’s Gladstone Institutes. Yamanaka did most of the IPS cell work at his main lab in Japan.
"My colleague sent me the image, and it was, wow," Yamanaka said, offering a brief, modest smile. "We had beating human heart cells, made from IPS cells."
Researchers use stem cells to show connection between neural cell disruption and Parkinson’s disease
A diverse team of biologists has shown using induced pluripotent stem cells (iPSCs) that a gene mutation that causes malformations in the structure of the nuclear envelope of neural cells, is associated with Parkinson’s disease. In their paper published in the journal Nature, they describe how they found iPSC cells taken from Parkinson’s patients over time demonstrated the same cell disruption found in neural cells taken from other deceased patient’s with the disease. They also found that by introducing a compound known to disrupt the gene mutation, that they could reverse the cell malformation.
Parkinson’s disease is a degenerative disorder of the nervous system characterized by shaking, slowness of movement and difficulty walking. Over time most patients succumb to dementia and eventually die. Much research has centered on the disruption and death of dopamine-generating cells as the root cause of the disorder despite evidence that such a disruption would not result in all of the symptoms Parkinson’s patient’s exhibit. For that reason, researchers have looked to other causes.
In this new effort, the researchers looked at possible reasons for disruption to the nuclear envelope, the thin film that separates the nucleus from the cytoplasm in neural cells. Such disruptions have been associated with Parkinson’s but no definitive correlation has been found, until now.
To gain a better understanding of what might be causing such disruptions, the research team obtained samples of induced iPSCs from Parkinson’s patients and allowed them to grow in an external environment. They noted that the same disruptions occurred as the iPSCs grew into neural cells, suggesting a genetic cause. Prior research had indicated that a mutation of the LRRK2 gene was connected to Parkinson’s disease but no clear indication of the mechanism involved had been found. Testing the cells derived from the iPSCs showed the same mutation, implicating it as a possible cause of the disorder. The researchers also induced the mutation in human embryo stem cells and found that they too developed the same disruption as they grew into neural cells as was found with the iPSCs.
Next the researchers generated a line of iPSCs minus the mutation and found that the cells did not develop the disruptions. They followed that up by adding a chemical compound known to disrupt the mutation to already affected cells and discovered that it prevented them from being disrupted as well.
The researchers don’t know why the mutation occurs but believe a new therapy for treating Parkinson’s patients might be on the horizon as a result of their research.
(Source: medicalxpress.com)
Why stem-cell science thrives in Japan
It’s easy to take for granted the epic scale of what some scientists are attempting these days. When the news broke a couple of weeks ago that Japanese scientists had turned normal cells from a mouse into eggs, and then fertilized them and seen them develop into baby mice, I thought it was pretty cool.
But I wasn’t that surprised.
I knew that Katsuhiko Hayashi — one of the scientists involved — was doing fascinating research on stem cells at Kyoto University, and so this seemed a natural progression for his work to take.
Then I spoke to him and his boss. What they said reminded me that they are attempting to do something that, until recently, would have blown the mind of almost any scientist, philosopher or other kind of intellectual there’s ever been throughout the whole of human history.
Mitinori Saitou, who is head of Hayashi’s lab at the Department of Anatomy and Cell Biology in the Graduate School of Medicine, was highly ambitious from an early age, and became particularly focused when he was doing his PhD as a young man.
"I got interested in germ-cell biology and the regulation of the cell fates," he told me, "hoping that one day it may be possible to develop a methodology to control cellular fate at will."
To control fate: It’s like something out of a Greek myth.
Nobel Winner’s Stem Cells to Be Tested in Eye Malady in 2013
Stem cells derived from a mouse’s skin won Shinya Yamanaka the Nobel Prize. Now researchers in Japan are seeking to use his pioneering technology for an even greater prize: restoring sight.
Scientists at the Riken Center for Developmental Biology in Kobe plan to use so-called induced pluripotent stem cells in a trial among patients with macular degeneration, a disease in which the retina becomes damaged, resulting in loss of vision, Yamanaka told reporters in San Francisco.
Companies including Pfizer Inc. (PFE) are already planning trials of stem cells derived from human embryos. The Japanese study will be the first to use a technology that mimics the power of embryonic cells while avoiding the ethical controversy that accompanies them.
“The work in that area looks very encouraging,” John B. Gurdon, 79, a professor at the University of Cambridge who shared the Nobel with Yamanaka, said in an interview in London.
Yamanaka and Gurdon shared the 8 million Swedish kronor ($1.2 million) award for experiments 50 years apart that showed that mature cells retain in latent form all the DNA they had as immature stem cells, and that they can be returned to that potent state, offering the potential for a new generation of therapies against hard-to-treat diseases such as macular degeneration.
Neural-Like Stem Cells From Muscle Tissue May Hold Key to Cell Therapies for Neurodegenerative Diseases
Scientists at Wake Forest Baptist Medical Center have taken the first steps to create neural-like stem cells from muscle tissue in animals. Details of the work are published in two complementary studies published in the September online issues of the journals Experimental Cell Research and Stem Cell Research.
“Reversing brain degeneration and trauma lesions will depend on cell therapy, but we can’t harvest neural stem cells from the brain or spinal cord without harming the donor,” said Osvaldo Delbono, M.D., Ph.D., professor of internal medicine at Wake Forest Baptist and lead author of the studies.
“Skeletal muscle tissue, which makes up 50 percent of the body, is easily accessible and biopsies of muscle are relatively harmless to the donor, so we think it may be an alternative source of neural-like cells that potentially could be used to treat brain or spinal cord injury, neurodegenerative disorders, brain tumors and other diseases, although more studies are needed.”
In an earlier study, the Wake Forest Baptist team isolated neural precursor cells derived from skeletal muscle of adult transgenic mice (PLOS One, Feb.3, 2011).
In the current research, the team isolated neural precursor cells from in vitro adult skeletal muscle of various species including non-human primates and aging mice, and showed that these cells not only survived in the brain, but also migrated to the area of the brain where neural stem cells originate.
Another issue the researchers investigated was whether these neural-like cells would form tumors, a characteristic of many types of stem cells. To test this, the team injected the cells below the skin and in the brains of mice, and after one month, no tumors were found.
“Right now, patients with glioblastomas or other brain tumors have very poor outcomes and relatively few treatment options,” said Alexander Birbrair, a doctoral student in Delbono’s lab and first author of these studies. “Because our cells survived and migrated in the brain, we may be able to use them as drug-delivery vehicles in the future, not only for brain tumors but also for other central nervous system diseases.”
In addition, the Wake Forest Baptist team is now conducting research to determine if these neural-like cells also have the capability to become functioning neurons in the central nervous system.
(Source: newswise.com)
Could Stem Cells Treat Autism? Newly Approved Study May Tell
Autism researchers have been given the go-ahead by the U.S. Food and Drug Administration to launch a small study in children with autism that evaluates whether a child’s own umbilical cord blood may be an effective treatment.
Thirty children with the disorder, aged 2 to 7, will receive injections of their own stem cells from umbilical cord blood banked by their parents after their births. All of the cord blood comes from the Cord Blood Registry, the world’s largest stem cell bank.
Scientists at Sutter Neuroscience Institute, in Sacramento, Calif., said the placebo-controlled study will evaluate whether the stem cell therapy helps improve language and behavior in the youngsters.
There is anecdotal evidence that stem cell infusions may have a benefit in other conditions such as cerebral palsy, said lead study investigator Dr. Michael Chez, director of pediatric neurology at the institute.
"We’re hoping we’ll see in the autism population a group of patients that also responds," Chez said. Other autism and stem cell research is going on abroad, but this study is the first to use a child’s own cord blood stem cells.
Chez said the study will involve only patients whose autism is not linked to a genetic syndrome or brain injury, and all of the children will eventually receive the stem cells.
Human neural stem cells study offers new hope for children with fatal brain diseases
New findings demonstrate potential to treat a wide variety of disorders that affect myelin
Physician-scientists at Oregon Health & Science University Doernbecher Children’s Hospital have demonstrated for the first time that banked human neural stem cells — HuCNS-SCs, a proprietary product of StemCells Inc. — can survive and make functional myelin in mice with severe symptoms of myelin loss. Myelin is the critical fatty insulation, or sheath, surrounding new nerve fibers and is essential for normal brain function.
This is a very important finding in terms of advancing stem cell therapy to patients, the investigators report, because in most cases, patients are not diagnosed with a myelin disease until they begin to show symptoms. The research is published online in the journal Science Translational Medicine.
Myelin disorders are a common, extremely disabling, often fatal type of brain disease found in children and adults. They include cerebral palsy in children born prematurely as well as multiple sclerosis, among others.
Using advanced MRI technology, researchers at OHSU Doernbecher Children’s Hospital also recently recognized the importance of healthy brain white matter at all stages of life and showed that a major part of memory decline in aging occurs due to widespread changes in the white matter, which results in damaged myelin and progressive senility (Annals of Neurology, September 2011).
Cell reprogramming: much promise, many hurdles
Research in reprogrammed cells, which on Monday earned the 2012 Nobel Prize, has been hailed as a new dawn for regenerative medicine but remains troubled by several clouds.
Britain’s John Gurdon and Japan’s Shinya Yamanaka were honoured with the world’s paramount award in medicine for induced pluripotent stem cells (iPSCs).
They discovered that a mature, adult cell can be turned back to an infant, versatile state called a stem cell.
First theorised in the late 19th century, stem cells are touted as a source of replacement tissue, fixing almost anything from malfunctioning hearts and lungs, damaged spines, Parkinson’s disease or even baldness.
The first human trials were launched only in 2010, and progress has been dogged by the contested use of stem cells taken from early-stage embryos, where the most adaptable, or pluripotent, cells are found.
Created by Yamanaka in 2006, iPSCs ease the moral row as they derive from adult cells and not embryos, said University of Oxford ethics professor Julian Savulescu. Ordinary skin cells can be used as the starting material.
"Many people objected to the creation of embryos for research, describing it as cannabalizing human beings," he said.