Posted on Jul 10, 2009 by Sergio Ulloa
In recent years, much of the debate and controversy surrounding stem cells has been about the ethics of stem cells and embryonic stem cells in particular. However, recent scientific advancements not just in the possible future applications of stem cells, but also in how to produce or create stem cells may render a large amount of ideologically based criticism irrelevant.
Just to be clear, the only way to get embryonic stem cells is to cultivate them from fertilized human eggs. However, the reason for the interest into them is that embryonic stem cells are what are known as pluripotent, which means they are capable of developing into almost any type of cell in the body. While research into stem cells has continued unhindered in many places around the world, other places such as the United States have previously placed limits on federal funding for research into embryonic stem cells.
During George W. Bush's presidency federal monies were only permitted to be given to research into non-embryonic stem cells and generations of stem cells derived from embryos before August 9, 2001. Despite the fact U.S. legislators passed bills in support of broadening federal funding for embryonic stem cells
on multiple occasions during Bush's presidency, even going so far as to include ethical restraints and requirements on the source of the embryos, Bush vetoed them out of hand. However, President Obama removed certain restrictions on federal funding by executive order in March this year but left the drawing up of legal and ethical rules involved in who is eligible to receive money to the National Institute of Health
Thankfully the previous administration's intransigence on the subject seems to have done little to hinder serious progress in many areas. Recent news has witnessed the explosion in stem cell related scientific discoveries that could lead to impressive developments in treating serious diseases and illnesses. One recent study by the University of South Florida in conjunction with the James A. Hadley Hospital found that a human growth factor or hormone called the granulocyte-colony stimulating factor (GCSF) can help improve memory and learning behavior in mice with Alzheimer's
. GCSF is a hormone that promotes white blood cells and blood stem cells in the body's bone marrow and is usually administered to cancer patients who have gone through chemo or radiation therapy.
The study's authors found that mice with Alzheimer's that were given filgrastim (a commercially available GCSF compound) injections under the skin showed remarkably improved memory after 3 weeks of treatment. Beta amyloid, a protein that builds up in the brain and is considered to be one of the main causes of Alzheimer's, was found to have been reduced by 36-42 % in mice with Alzheimer's symptoms. This could lead to an effective therapy for patients with Alzheimer's and the Alzheimer's Drug Discovery Foundation has already decided to fund a small clinical trial in the University of South Florida's Byrd Alzheimer's Center to test the safety and effectiveness on human Alzheimer's patients.
In other mouse related science news, researchers at the Hebrew University-Hadassah Medical School found that injections of stem cells can reverse neural birth defects
. The test mice's mothers were given heroin during pregnancy to induce defects in the brain, the test mice then received injections of transplanted neural stem cells from embryonic mice directly into the brain. The tests showed that even though most of the transplanted stem cells didn't survive, they seemed to spur the brain to repair itself. By a function called the bystander or chaperone effect, the stem cells seem to not only produce replacement cells but also send out signals that induce other cells in the body to start repairing and maintaining organs. There are concerns, however, as the cells used were extracted from mice embryos they are sometimes considered a foreign object by the body's immune system and may in some cases lead to tumors forming in the body.
But what if you didn't need to use embryonic stem cells? If the need for a fertilized egg to make stem cells was removed, then moral complaints against stem cell research and treatment from vociferous anti-abortion factions have no legs to stand on. Enter the testicle. Kinarm Ko, Hans Schöler and a team at the Max Planck Institute for Molecular Biomedicine in Münster have been able to extract a certain type of cell from mice testes and turn them into pluripotent stem cells
without the need to apply genes, viruses or reprogramming proteins to affect the change. They started with a type of cell called a germline stem cell which is not only rare in the testis (you will only find a few in the 10,000 or so cells in tissue of a mouse testis) but also rarely tends to reproduce itself. This germline stem cell tends to do only one thing in its natural environment, and that one job is to make lots and lots of sperm. In an unusual twist, the researchers found it was barely more than a simple trick to get these cells to reprogram themselves. Given a little space in a Petri dish, these germline stem cells will alter themselves to become pluripotent in as little as two weeks, after which they start reproducing very quickly. While further testing will be needed to determine whether this could be applied to humans, so far the germline cells extracted from the mice testis are capable of generating the same kinds of cells as embryonic stem cells and far surpass previous attempts to artificially reprogram a cell in both safety and the ease of producing them.
Breakthroughs like this and others such as the ability to reprogram DNA from adult skin cells to make induced pluripotent stem cells
(iPS for short) allow us to understand stem cells' roll in the body more thoroughly and could eventually lead us to a less ethically questionable ways to produce stem cells which may also be safer for us medicinally as well. Not only could this lead to a wide variety of treatments for debilitating illnesses like Alzheimer's, brain damage, cancer and many more, but also the ability to treat these issues while maintaining a high level of ethical standards.