Canadian scientists report that they have identified insulin-producing stem cells in the adult mouse pancreas, a finding they say offers hope for people with diabetes. Team leader Simon Smukler called the discovery 'very exciting', since scientists have been searching for pancreatic stem cells for some time. The researchers, based at the University of Toronto, published their findings in the journal Nature Biotechnology. Meanwhile, a group of US researchers has shown that embryo stem cells (ES cell) can repair damaged heart tissue in rats. The team, based at the Mayo Clinic College of Medicine in Minnesota, published their results in the American Journal of Physiology.
People with diabetes either do not produce enough insulin, or do not respond to the hormone's effects. Researchers are hoping to develop new treatments for this disorder by transplanting insulin-producing 'beta' cells into the pancreas. Earlier this year, US stem cell researcher Doug Melton cast doubt on the existence of pancreatic stem cells, but the Canadian study suggests otherwise.
The scientists now hope to continue their research, to show that the cells they isolated are true stem cells. Interestingly, the pancreas cells grew into both beta cells and nerve cells, a surprise finding given that these two cell types are thought to arise from separate cell-lines during development. 'The idea that a single cell within the pancreas could make both beta cells and neurons is intriguing', said Smukler.
The Mayo Clinic study showed that transplants of rat embryo stem cells can repair the damage caused by heart attack. After inducing heart attacks in rats, the researchers injected ES cells into the damaged areas. After three weeks, they found that the heart was working better in the treated animals, compared to rats that did not receive the ES cell therapy. The effect did not diminish over the 12 week follow-up period, and there was no evidence that the treatment caused any serious side effects. Team leader Andre Terzic said that 'based on our experimental findings, embryonic stem cells present an opportunity for reparative therapy with stable benefit in myocardial infarction [heart attack]'.