Protein in Pancreas May Lead to New Therapy for Type II Diabetes

Researchers at the Burnham Institute for Medical Research and the University of California, San Diego have found parallels between how the pancreas develops in the embryo and type II diabetes (also known as adult diabetes). When the pancreas develops in an embryo, a protein called Wnt (pronounced “wint) helps control how the cells mature into insulin-producing cells. In most adults, the pancreas contains very little Wnt protein, but in people with type II diabetes Wnt protein is abundant in the pancreas. The authors suggest that Wnt could be a target for new type II diabetes therapies.

Experimental Diabetes Research: January 20, 2009
CIRM funding: Seung-Hee Lee (T2-00004), Carla Demeterco (T2-00003)

Related Information: Press Release, Burnham Institute for Medical Research

Neural Cells Can Mature into Ear Sensory Cells

Researchers at the University of California, Davis have coaxed cells from the brain to mature into the minute hair cells in the ear that are required for hearing. For many people with hearing loss, these tiny hair cells have died, leaving people unable to sense vibrations caused by sound. Regrowing functional hair cells that will sway in response to sound and send appropriate signals to the brain has been a major goal for stem cell researchers. In this work, the team found a population of cells in the lateral ventricle of the brain that they were able to transform into the delicate hair cells. The team is now testing whether those cells are able to transmit sound signals in animal models.

Proceedings of the National Academy of Sciences: December 30, 2008
CIRM funding: Dongguang Wei (T1-00006), Ebenezer Yamoah (RS1-00453)

Related Information: Press Release, UC Davis Health Care System, Yamoah bio

Embryonic Stem Cells Generate Model for ALS

Researchers at the Salk Institute for Biological Sciences have grown embryonic stem cells into the motor neurons and support cells that underlie amyotrophic lateral sclerosis (ALS). Also known as Lou Gherig’s Disease, ALS has no cure and no effective treatment. In this disease, the motor neurons slowly degenerate leaving a person paralyzed. Why the neurons die is not known, however the support cells called astrocytes have long appeared to play a role. Now researchers have coaxed embryonic stem cells to form the motor neurons and astrocytes in a lab dish to better understand their relationship in ALS. What they learned is that astrocytes containing a mutation associated with ALS killed off the neighboring motor neurons. This mutation is in a gene that makes a protein whose normal role is to protect the body from damaging oxygen free radicals. When the group grew these same cells in the presence of a powerful anti-oxidant, the motor neurons survived. In addition to understanding the biology of ALS, the group thinks they could use this system to screen drugs that may be able to treat ALS.



Cell Stem Cell: December 4, 2008
CIRM funding: Fred H. Gage (RC1-00115)

Related Information:Press release, Salk Institute for Biological Sciences, Gage  bio

Origin of blood stem cells found to be in the lining of blood vessels

Researchers at UC, Los Angeles have found that blood-forming stem cells in mice have their origins in the endothelial cells that line blood vessels during mid-gestation. These cells eventually move to the bone marrow where they generate all the cells of the blood system throughout life. Researchers have long known that blood-forming stem cells arise from the blood vessels, but didn’t know exactly which cell type acted as the source. Now that the source is know, the researchers want to learn what signals those endothelial cells to begin producing blood-forming stem cells. This information could eventually help researchers learn how to create those stem cells in the lab and maintain the cells in the stem cell state rather than forming mature cell types. Currently, it isn’t possible to grow blood stem cells in large quantity in the lab. Having a source of these cells would be useful for bone marrow transplants to treat cancer or for research purposes.

Cell Stem Cell: December 4, 2008
CIRM funding: Ann Zovein (T1-00005)

Related Information: Press release,The Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at UCLA

Genetic Factor Enables Immature Cells to Form Normal Heart Tissue

Researchers at the Gladstone Institute for Cardiovascular Disease found a genetic factor that helps in the earliest stages of heart development as the primitive tube loops around on itself and forms the separate chambers. This factor -- a short relative of DNA called microRNA -- has an identical counterpart in humans, leading the researchers to believe that their work in fish is likely to relate directly to human heart development. When the researchers interfered with this microRNA while the heart was developing, the immature heart muscle cells failed to mature and the heart chambers didn’t form normally. These heart muscle precursors are a stage in between the embryonic stem cell and the mature heart muscle cell. The heart is among the first organs to develop and also the most critical. When the heart doesn’t develop properly the embryo dies. What’s more, common birth defects involve abnormalities in how these chambers form. Understanding all the steps between an embryonic stem cell and the mature heart cell could help researchers prevent or treat birth defects of the heart.

Proceedings of the National Academy of Sciences: November 12, 2008
CIRM funding: Kathy Ivey (T2-00003), Deepak Srivastava (RC1-00142)

Related Information: Press release, Gladstone Institute of  Cardiovascular Disease, Srivastava bio

Protein found to direct embryonic stem cells as they mature

Researchers at the Stanford University School of Medicine have found that clusters of embryonic stem cells in a lab dish share some unexpected similarities with actual embryos. These clumps, called embryoid bodies, consist of hundreds of cells, many of which begin to form more mature cell types. For example, they often contain groups of primitive heart muscle cells that beat visibly. In this work the researchers found that the embryoid bodies also contain a line of cells that resemble an embryonic structure called the primitive streak. This streak is the first indication that the embryo has a top and bottom or back and front. Blocking molecules found in the embryoid body primitive streak pushed those cells to form a group of cells that make up skin and nerves. Enhancing those molecules pushed the cells to form cell types like muscle and intestine. This work could help researchers learn how to push embryonic stem cells to form particular cell types, which is a necessary step in developing stem cell-based therapies.

Cell Stem Cell: November 6, 2008
CIRM funding: Roel Nusse (RC1-00133-1)

Related Information: Press release, Stanford Stem Cell Biology and Regenerative  Medicine Institute, Nusse lab page

Genetic Factors Found to Speed Embryonic Stem Cell Division

Researchers at UC, San Francisco developed a novel way of finding out the role of DNA-relatives called microRNA. These molecules are known to turn genes on and off and appear to regulate whether embryonic stem cells remain as stem cells or develop into mature cell types, but learning which genes are controlled by each microRNA has been a challenge. Using this screen, the researchers found 14 microRNAs that speed up cell division; of those, five are commonly found in human embryonic stem cells. It turns out these microRNAs deactivate genes that slow the cell cycle, essentially releasing the brakes on cell division. Identifying the role of these and other microRNAs could help researchers understand how to hold embryonic stem cells in their immature state, guide how those cells mature, or even develop treatments for cancer.

Nature Genetics: November 2, 2008
CIRM funding: Yangming Wang (T1-00002)

Related Information: Press release, UCSF Institute for Regeneration Medicine, Blelloch bio