Discovery of mechanism that regulates the development of stem cells into neurons



Men who survived childhood leukemia treatment into adulthood were more likely to have low bone mineral density than other adults their age, putting them at risk of osteoporosis and bone fractures, according to a new study. The study, led by James G. Gurney, Ph.D., of the University of Michigan Comprehensive Cancer Center, found that 24

Full Post: Men who survive childhood leukemia have lower bone mineral density

Researchers at the University of Southern California (USC) have identified a novel mechanism in the regulation and differentiation of neural stem cells.

Researchers found that the protein receptor Ryk has a key role in the differentiation of neural stem cells, and demonstrated a signaling mechanism that regulates neuronal differentiation as stem cells begin to grow into neurons. The study will be published in the Nov. 11 issue of the journal Developmental Cell , and is now available online.

The findings could have important implications for regenerative medicine and cancer therapies, says Wange Lu, Ph.D., assistant professor of biochemistry and molecular biology at the Keck School of Medicine of USC, and the principal investigator on the study.

“Neural stem cells can potentially be used for cell-replacement therapy for neurodegenerative diseases such as Alzheimer’s and Parkinson’s Disease, as well as spinal cord injury,” Lu says. “Knowledge gained from this study will potentially help to generate neurons for such therapy. This knowledge can also be used to inhibit the growth of brain cancer stem cells.”

During brain development, neural stem cells respond to the surrounding environment by either proliferation or differentiation, but the molecular mechanisms underlying the development of neural stem cells and neurons are unclear, Lu notes.

Ryk functions as a receptor of Wnt proteins required for cell-fate determination, axon guidance and neurite outgrowth in organisms. Researchers at the Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at USC analyzed sections of the forebrain in animal model embryos to investigate Ryk’s function in vivo.

They found that during neurogenesis, when neural stem cells start to grow into neurons, Ryk protein is cleaved and translocates to the cell nucleus to regulate neuronal differentiation.

This finding is extremely important for understanding the regulation of self-renewal and differentiation of neural stem cells, Lu says. Previous research has shown that Ryk functions as a receptor of Wnt proteins. However, the role of Ryk in neural stem cells and the molecular mechanism of Ryk signaling have not previously been known.

“This study will help in our efforts to produce nerve cells from embryonic stem cells, and may lead to the development of new strategies for the repair of the nervous system, using protein or small molecule therapeutic agents,” says Martin Pera, Ph.D., director of the Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at USC.

Further research is needed to explore how Ryk regulates neuronal gene expression, Lu says. Researchers are now expanding their research to studies of differentiation of human embryonic stem cells into neural stem cells and neurons. These studies are very important for regenerative medicine and drug discovery for therapy of neurodegenerative diseases.

http://www.usc.edu/

Link




Natural changes in voltage that occur across the membrane of adult human stem cells are a powerful controlling factor in the process by which these stem cells differentiate, according to research published by Tufts University scientists. Tufts doctoral student Sarah Sundelacruz, Professor of Biology Michael Levin, and Chair of Biomedical Engineering David L. Kaplan (corresponding

Full Post: New set of controls for stem cells discovered



Researchers have identified a stage during dopamine neuron differentiation that may be an ideal time to collect human embryonic stem cells for transplantation to treat Parkinson’s disease, according to data presented at Neuroscience 2008, the 38th annual meeting of the Society for Neuroscience. Lorraine Iacovitti, Ph.D., professor and interim director of the Farber Institute for

Full Post: Researchers identify best time for stem cell collection for Parkinson’s therapy



In the December 1st issue of G&D, Dr. Fred H. Gage (The Salk Institute for Biological Studies) and colleagues reveal a role for the Hippo signaling pathway in the regulation of vertebrate neural development, identifying new factors - and potential therapeutic targets - that may be involved in congenital brain size disorders and neurological tumor formation. Their

Full Post: New molecular insight into vertebrate brain development



Stem cells are the body’s primal cells, retaining the youthful ability to develop into more specialized types of cells over many cycles of cell division. How do they do it? Scientists at the Carnegie Institution have identified a gene, named scrawny, that appears to be a key factor in keeping a variety of stem cells

Full Post: Gene named scrawny keeps stem cells healthy



Stem cell researchers at UCLA have proven definitively that blood stem cells are made during mid-gestational embryonic development by endothelial cells, the cells that line the inside of blood vessels. While the anatomic location in the embryo where blood stem cells originate has been well documented, the cell type from which they spring was less

Full Post: Scientists show that endothelial cells give rise to blood stem cells