Pancreatic Stem Cell Study

Pancreatic Stem Cell Study

Researchers at the Scripps Research Institute have been studying the roles of two proteins in the proliferation of pancreatic stem cells. The research may eventually lead to therapies for Type I diabetes, known as reverse-insulin dependent diabetes mellitus (IDDM). The disease is an immune system disease in which the body’s immune system destroys the cells which produce insulin.

In the study, described in a press release, the researchers examined the roles of two proteins, BMP4 and Id. Id proteins bind to and inhibit another family of proteins which regulate gene expression, and the researchers theorized that this could keep the cell from differentiating and increase its proliferation. They already knew that the BMP protein increased the expression of the Id protein in other cell types, and wanted to see what happened when it was applied to pancreatic stem cells.

The researchers had several findings. They identified abundant BMP and Id proteins in the embryonic mouse pancreas, determined that the BMP4 protein signaling was essential in proliferation of the progenitor cells, and that the growth correlated with Id expression. They also found that if they inhibited the production of BMP4, the duct cells of the pancreas, which are thought to be one source of pancreatic stem cells, had reduced proliferation. There was also an increase in the expression of another factor required for differentiation.

There are still significant questions remaining, such as at how extensive the replacement of insulin-producing cells is during the elimination of them, and how the replacement occurs. However, identification of the role of these two proteins helps explain the functioning of a healthy pancreas and the balance it maintains between the proliferation and the differentiation of the stem cells which give rise to insulin-producing beta cells. In theory a therapy could be developed that, by regulating the levels of BMP4 and therefore of the Id proteins, would cause the cells to proliferate to the desired number and then to differentiate.

Survey Shows Americans Support hESC Research

Survey Shows Americans Support hESC Research

The Coalition for the Advancement of Medical Research (CAMR) has issued a press release stating that its latest poll shows that 72% of Americans support embryonic stem cell research. The poll was a sampling of approximately 1000 people nationwide and had a 3% margin of error, according to the release. The release also says that several Senators from both parties are pressuring Bill Frist for a vote on the embryonic stem cell funding bill.

Not being one to trust survey numbers as reported by the surveying organization without question, I went to the website for the survey (PDF). There doesn’t seem to be anything particularly ambiguous or poorly phrased in the 2 questions that were asked. The first gave a definition of embryonic stem cells as cells derived from leftover fertilized eggs from fertility clinics that would otherwise be thrown away and that have the potential to develop into any cell in the body. The respondents were asked whether they strongly favor, somewhat favor, somewhat oppose, or strongly oppose such research. The second question asked whether or not the Senate should vote on the issue. Respondents were categorized by sex, age group, geographical area of country, children in household, household size, household income, metropolitan or non-metropolitan area, race, and education. The oppose was generally in the 20-25% range across all groups, and the favor was generally in the 70-75% range across all groups. Support for hESC research generally went up as income did. The group most likely to either somewhat oppose or strongly oppose hESC research were people from a non-metropolitan area (29%) or people who had not completed high school (29%). Hispanics only favored hESC research by 64%, compared to 84% for blacks and 73% for whites. (There were many more white respondents. I am not a statistician and don’t know how this reflects on the survey margin of error.)

If I were in Congress, I would pay attention to this.

Stem Cell Gene For Eye Development

Stem Cell Gene For Eye Development

This is not research related to treatment for any disease, but instead is basic biological information about eyes and neural stem cells. Researchers at the University of North Carolina at Chapel Hill have found that levels of the expression of the SOX2 gene are key to development of neural tissue in the eye. According to a press release republished on Emax Health, the researchers found that disrupting the gene in the neural retinal stem cells of mice led to abnormal development in the eye, and that the extent of the abnormality varied with the amount of gene disruption. Neural retinal progenitor cells which had a complete loss of the gene could neither differentiate into other cells nor retain their pluripotency.

SOX2 is a transcription factor gene which controls the expression of other genes, including Notch1, which is significant in some other types of stem cells as well.

It would be interesting to see what impact SOX2 has on other types of neural cells.