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Cerebral spinal fluid guides stem cell development in the brain | Science Codex

In STEM CELLS IN THE NEWS on March 9, 2011 at 1:50 pm

Cerebral spinal fluid guides stem cell development in the brain

Posted On: March 9, 2011 – 5:30pm

Cerebrospinal fluid—the clear and watery substance that bathes the brain and spinal cord—is much more important to brain development than previously realized.

Howard Hughes Medical Institute investigator Christopher Walsh, his postdoctoral fellow Maria Lehtinen, former student Mauro Zappaterra, and their colleagues have discovered that cerebrospinal fluid (CSF) contains a complex mix of proteins that changes dramatically with age. In the lab, CSF by itself is enough to support the growth of neural stem cells, and this effect is particularly robust in young brains.

What’s more, the protein make-up of CSF in people with malignant brain cancer is different from that of healthy people, the researchers found. “This suggests that the CSF can make a more supportive or less supportive environment for tumor growth,” notes Walsh, Chief of Genetics at Children’s Hospital Boston. The work is published in the March 10, 2011, issue of the journal Neuron.

Centuries ago, philosophers thought spinal fluid held particular importance for health. The French philosopher and mathematician René Descartes, for example, described the brain as a simple hydraulic machine, pumping fluid—pneuma anima, or ‘animal spirits’—through the body’s nerves like a Parisian water fountain.

“Recent history has not been so kind to CSF,” Walsh notes. Today, most researchers think of it as a relatively simple salt solution that gives the brain buoyancy and helps protect it from knocking against the skull.

Several years ago, Walsh’s work on brain development led him to suspect that there is much more to the unassuming fluid. He noticed that neural stem cells tend to line up around the brain’s inner chambers, where CSF is stored, and stick cellular fingers, called cilia, into the pool of CSF. “That made us think, there’s got to be something in CSF that’s binding to cilia and controlling how the cell divides,” Walsh says.

In 2007, Zappaterra and Walsh performed the first comprehensive analysis of embryonic human CSF. They found it holds hundreds of different proteins that are involved in a variety of tasks, including cell growth, transport, support, and signaling. “We were amazed at the diversity of substances that we identified in there, many of which people had no clue would be there,” Walsh says.

In the new study, the researchers took small pieces of embryonic rat brain tissue and, using a thin platinum wire, deftly moved them onto culture plates made up of CSF from rats of different ages. They found that when brain stem cells bathe in CSF from young rats, they furiously divide. In contrast, when grown on CSF from older rats, there is less cell division, but CSF from all ages contains all that is needed to maintain brain stem cells in a dish. Subsequent analysis of the fluid showed that the amount of a protein called Insulin-like growth factor 2 (Igf2) strongly correlates with the level of cell division.

The researchers then teamed up with a group of scientists from Beth Israel Deaconess Medical Center that has a unique collection of CSF samples isolated from people with various stages of glioblastoma, a type of brain cancer in which tumors infiltrate the whole brain. The Beth Israel Deaconess group, led by Eric Wong, found that people with more advanced cancer have higher levels of Igf2 in CSF than do those with less severe forms of the disease.

The scientists don’t know whether the increase in Igf2 levels is partly causing the cancer, or is instead a consequence of living with the disease. “We certainly don’t think Igf2 is the only contributor to the pathology, because glioblastomas are very complex. But it may be an interesting biomarker to consider,” says Maria Lehtinen, who is a joint first author of the study, along with Zappaterra.

Taking a closer look at CSF could be helpful in other brain diseases as well. Some researchers are investigating whether the levels of certain proteins, like Tau and Beta amyloid, might be used as predictors of Alzheimer’s disease, for example.

Because CSF is made in the choroid plexus—the tiny knob in the brain’s chambers that forms the interface between the bloodstream and the brain—it could explain part of the mystery of how changes in the body link up to the brain. For example, if you exercise a lot, you form more brain cells, but no one knows exactly how this works.

“We sometimes get very spiritual about this,” Walsh says, laughing. “It presents mechanisms about how different parts of the body are talking to each other in ways that I hadn’t really conceived of before.”

 

via Cerebral spinal fluid guides stem cell development in the brain | Science Codex.

The Future of Stem Cell Research: BCVS Advances in 2010 – AHA Science Network

In STEM CELLS IN THE NEWS on March 9, 2011 at 1:14 pm

Basic Cardiovascular Science Advances for 2010: The Future of Stem Cell Research

By Dr. Mark Sussman

The mission of our council is to improve understanding of mechanisms of basic cardiovascular regulation to support the development of new therapies and insights into clinical cardiovascular disease. Special emphasis is placed on integrating molecular/cellular and physiological approaches to address problems relating to functional genomics, cell signaling, myocardial biology, circulatory physiology, pathophysiology and peripheral vascular disease. The council plays a major role in linking basic science to clinical science and is concerned with advancing and applying knowledge derived from basic science to the patient.

Annually AHA asks all of its Councils and science groups what in their estimation have been the most important advances in their respective fields within the past year. We have pulled out of all of those suggestions the ones that came from or are relevant to our community. Several studies this year brought the future of medicine closer to the present with new insight into emerging technologies. These studies evaluate the role of stem cells in cardiac repair and their ability to differentiate into cardiac myocytes and the ability of the heart to replace and regenerate myocytes on its own. The findings from stem cell therapy have been shown to improve quality of life and survival in patients with chronic heart failure and support the development of future cell based therapeutics.

Dr. Mark Sussman is the Chair of the BCVS Council. He is the Distinguished Professor of Biology at the SD

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Posted by Melissa AHA Science on Mar 9, 2011 9:13 AM CST

Influential research misses financial conflicts | Reuters

In BUSINESS OF STEM CELLS on March 9, 2011 at 12:40 pm

A pharmacy employee dumps pills into a pill counting machine as she fills a prescription while working at a pharmacy in New York December 23, 2009. REUTERS/Lucas Jackson

By Frederik Joelving

NEW YORK | Wed Mar 9, 2011 1:51am EST

NEW YORK (Reuters Health) – Scientists who review large sets of drug trials for medical journals often ignore financial conflicts that might warp the evidence, according to a study out Tuesday.

That’s more than just an academic problem, experts say, because the reviews are considered just about the strongest evidence that medical science can muster.

“It influences how physicians make decisions and how guideline panels come up with their guidelines,” said Brett D. Thombs, of McGill University and the Jewish General Hospital in Montreal, whose findings are published in the Journal of the American Medical Association (JAMA).

Thombs’ team found that of 29 reviews, or “meta-analyses,” of earlier drug trials — culled from top journals like JAMA and The Lancet — only two reported who had funded the original trials included in the review.

And none of the reviews mentioned whether the authors reporting on those trials had been paid by drugmakers.

Such financial ties have been linked to research inflating the benefits of new drugs and downplaying the risks, said Thombs.

 

Influential research misses financial conflicts | Reuters.

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