ROCHESTER, Minn. -- Mayo Clinic investigators have demonstrated that stem cells can be used to regenerate heart tissue to treat dilated cardiomyopathy, a congenital defect. Publication of the discovery was expedited by the editors of Stem Cells and appeared online in the "express" section of the journal's Web site at http://stemcells.alphamedpress.org/.
And yet people do not complain that mice get all the great medical treatments first. Why is that? My theory: the mice have somehow brainwashed us. PETA (People for the Ethical Treatment of Animals) are really a secret organization of people who are immune to mouse brainwashing. They pose as animal rights activists. But in reality they are human rights activists trying to move humans ahead of mice in priority for treatment development. If the mice find out that I've told you this then I'll probably have to get some cats as bodyguards.
The key here is that the scientists used embryonic stem cells. This seems pretty straightforward to try in humans except for the regulatory obstacles that stand in the way.
The team reproduced prominent features of human malignant heart failure in a series of genetically altered mice. Specifically, the "knockout" of a critical heart-protective protein known as the KATP channel compromised heart contractions and caused ventricular dilation or heart enlargement. The condition, including poor survival, is typical of patients with heritable dilated cardiomyopathy.
Researchers transplanted 200,000 embryonic stem cells into the wall of the left ventricle of the knockout mice. After one month the treatment improved heart performance, synchronized electrical impulses and stopped heart deterioration, ultimately saving the animal's life. Stem cells had grafted into the heart and formed new cardiac tissue. Additionally, the stem cell transplantation restarted cell cycle activity and halved the fibrosis that had been developing after the initial damage. Stem cell therapy also increased stamina and removed fluid buildup in the body, so characteristic in heart failure.
Embryonic stem cells are pluripotent. That means they can become all other cell types. Another way to create pluripotent stem cells without using an embryo will eventually make it possible to create pluripotent stem cells that do not raise big ethical opposition.
The use of stem cells to do repairs will be easier for some organs than others. I'm hopeful from reports like the one above that most heart problems will be among the easier problems to solve.
Looking ahead 20 years I'm most worried about cancer and brain aging. I would be surprised if organ failures will still kill a lot of people in industrialized countries 20 years from now. Will cancer become easily curable in 20 years? Maybe. But brain aging is going to be the hardest problem to solve.
|Share |||Randall Parker, 2008 September 11 11:13 PM Biotech Heart Cardiovascular|