Stem Cells and Blood Vessels

Stem Cells and Blood Vessels

Researchers at Uppsala University in Sweden have used embryonic stem cells from mice to identify a sugar molecule necessary for the formation of blood vessels and also used in cellular communication. According to the press release, the researchers developed blood vessels from embryonic stem cells which had been genetically modified. They discovered that “the production of the sugar molecule heparan sulfate is an absolute requirement for the formation of blood vessels.”

The researchers found the heparan sulfate functioned as a “glue” that held the growth factor VEGF and its receptors on the surface of the cell, enabling the cell to receive signaling to grow new blood vessels. Stem cells which could not form VEGF receptors or which did not produce heparan sulfate were unable to generate new blood vessels.

Additionally, the researchers found that heparan sulfate located on the support cells of the blood vessels had a much greater effect than heparan sulfate located on the endothelial cells.

This is one of the less publicized ways in which stem cell research is important—here we have something that is not a treatment for a particular disease but provides crucial information about cellular structure and mechanisms.

Cell Fusion

Cell Fusion

The Medford News in Oregon has a story today about a recent study at Oregon Health Sciences University which found that stem cells derived from bone marrow and transplanted fuse with both normal and diseased cells in the intestinal lining. The scientists have also observed cell fusion in benign tumors.

In the study, the scientists used bone marrow cells from a female mouse and transplanted them into a male mouse with intestinal cancer. The female donor cells were marked with a green fluorescent protein to identify them. Tumor cells were then identified with both the fluorescent marker and the male Y chromosome, indicating that cell fusion had occurred. Fusion was confirmed by examining a cell layer microscopically and identifying both the marker and a male enzyme.

The researchers hypothesize that cell fusion is the method by which the lining of the gut—which protects the rest of the body from ingested contaminants—is able to regenerate its cells as rapidly and frequently as it does. They think that cell fusion “jump-starts” the process.
The research also has implications for cancer research; cellular fusion may be a cause of genetic mutation that gives rise to malignancies. As I mentioned yesterday regarding the telomere study, frequent division or regeneration of cells appears to increase the likelihood of something going awry in the DNA and leading to cancer. The fusion of two cells seems that it would further increase the chances of a mutation arising.

More SCNT in California

More SCNT in California

I reported yesterday that UCSF was starting up its SCNT research. A press release now announces that Advanced cell Technology, which expanded recently from its existing office in Massachusetts to an additional facility in Alameda, California, has formed an Institutional Review Board and plans to begin SCNT research. The company will begin to solicit egg donors, who will receive no compensation except reimbursement of some expenses.

No word in the press release of where the funding will come from, but I imagine it will private money and not Prop 71 dollars, since those are still on hold.