The full image.
Human ES cells can potentially result in cells that resemble pancreatic beta cells (labeled ß).
Kroon et al., Nature Biotechnology , Advance Online Publication (20 February 08)
scientists have for the first time pushed the cells human embryonic stem to become functional pancreatic cells. The work, published online today in Nature Biotechnology , an important step towards the use of embryonic stem cells to treat diabetes.
One of the most sought after prize in embryonic stem (ES) cell research is a method of transforming cells in pancreatic beta cells. These cells produce insulin in response to sugar in the blood, and they are damaged or missing in type 1 diabetes If scientists could find a reliable way to make beta cells from human ES cells, they could be able to replenish the supply of patients. But so far nobody has managed to produce functional beta cells in the laboratory.
Now, developmental biologist Emmanuel Baetge and colleagues of the biotechnology company Novocell in San Diego, California, report that they have managed to coax human ES cells behave like beta cells in mice . For several years, the group has attempted to use the molecular signals that prompt pancreatic development in a fetus to direct human ES cells to become beta cells in a dish. In previous work, the researchers describe a technique that seemed to produce insulin-producing cells, but the cells do not respond to glucose, a key characteristic of working beta cells.
Thus, researchers have supported a step. Instead of trying to get mature beta cells in a dish, they treated ES cells with signals that coaxed them to form pancreatic endoderm, a type of cells similar to those in a human fetus aged 6 to 9 weeks. They implanted these immature cells into mice, hoping that the final signal that the formation of rapid beta cells could be provided by the organs of animals. Thirty days after implant, the researchers were able to detect the human version of C-peptide, a byproduct of the production of insulin in the blood of animals. (The researchers studied C-peptide instead of insulin, because it is easier to differentiate between versions of man and mouse.) After 2 months, the C-peptide levels human increased when mice received a dose of glucose, indicating that the implanted cells responding to blood sugar. Finally, the researchers selectively killed own beta cells of animals with a toxin, which usually leads to becoming diabetic mice. But rodents who received implanted human cells do not develop diabetes, showing that the implanted cells may take the place of the beta cells of the animals.
The work is "very important for the area," says diabetes expert Teresa Ku of the Beckman Research Institute in Duarte, California, whose group also worked on ways to turn the ES cells beta cells. Baetge said Novocell already meets the US Food and Drug Administration to discuss additional safety testing will be required before you can consider starting human trials. But Ku notes that it is difficult to determine whether the pancreatic endoderm cells are the self-renewal. If not, she said, they might give in a few years, and patients will undergo multiple transplants. A fully differentiated cell beta in the culture dish is always the safest bet, she said.
Related Sites
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- Another approach to the treatment of diabetes
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