August 19, 2013 | David F. Coppedge

Stem Cell Science Can Proceed Ethically

With adult and induced pluripotent stem cells in abundance, it should not be necessary to destroy human embryos to understand stem cell science.

Research with adult stem cells and induced pluripotent stem cells (iPSC) is continuing to produce amazing discoveries.

Self-healing heart:  The heart has a store of stem cells that is capable of natural regenerative capacity, scientists at Kings College London found (Medical Xpress), promising new treatment for heart failure:

The study, published today in the journal Cell, shows that if the stem cells are eliminated, the heart is unable to repair after damage. If the cardiac stem cells are replaced the heart repairs itself, leading to complete cellular, anatomical and functional heart recovery, with the heart returning to normal and pumping at a regular rate.

Also, if the cardiac stem cells are removed and re-injected, they naturally ‘home’ to and repair the damaged heart, a discovery that could lead to less-invasive treatments and even early prevention of heart failure in the future.

Reprogramming iPSC mutations:  For patients with a blood disease, researchers at Children’s Hospital of Philadelphia found they could take skin cells, create iPSCs from them, fix the mutation that causes the blood disease, re-inject them, and cure the disease (Science Daily).  “The technology for generating these cells has been moving very quickly,” the hematologist said.

Bad teeth?  Urine luckScience Daily reported a “number one source” for new teeth: stem cells in a patient’s own urine.  There’s potential in that liquid that is flushed down the drain to regenerate iPSCs that can be coaxed into creating hard parts of teeth structures.  “The system mimics normal tooth development, which results from an interaction between two different cell types; epithelial cells, which give rise to enamel, and mesenchymal cells, which give rise to the other three main components of teeth (dentin, cementum and pulp).”  iPSC technology is good news, because “their derivation avoids the controversial use of embryos” and the cells are not rejected by the patient.

Functional blood vessels:  Scientists at Harvard and Massachusetts General Hospital succeeded in growing functional blood vesses in vivo from iPSCs, Medical Xpress reported with the headline, “Patient, heal thyself.”  By overcoming several challenges with the method, they have shown that it is no longer necessary to rely on human embryonic stem cells to do the job.   According to a researcher, “the use of vascular precursors from human embryonic stem cells pose ethical and immunological concerns that are averted with the use of iPS-derived vasculogenic cells.”

Understanding adult stem cells:  European scientists are learning how stem cells in human skin differentiate, according to Science Daily.  By making proteins “shine,” they can monitor the developmental pathways as the stem cells form different tissues and organs in the skin, such as sweat glands, fat, or hair follicles.  They found that the cells do not follow a simple hierarchy from primitive stem cell to finished tissue, but “there are differentiated levels of stem cells and that it is their close micro-environment that determines” the tissue generated.  These findings will help regenerative medicine avoid “waking up” cells in the wrong place or time that might result in cancer.

Understanding embryonic stem cells:  Scientists are trying to understand the expression of embryonic stem cells – in mice.  Science Daily explored the paradox of how these cells can be marked with “on” and “off” regulatory marks simultaneously, like seeing a red and green light at the same time.  A more “nuanced” view of the genetic code is showing a method in the paradox: stem cells can be maintained in a “bivalent state” that allows them to go down either path, depending on context.

Understanding the differences:  By studying the substances in zebrafish cells that can convert body cells back to stem cells through a kind of “eraser” that removes the body cell’s memory of what it was, scientists are finding out how to make induced stem cells resemble embryonic cells more closely, Science Daily reported.  And why is this good?  “These multi-talented cells are the focus of much attention in biomedical research because experts hope to use them to regenerate damaged organs without having to resort to embryonic stem cells.

Learning from flatworms:  Flatworms (planaria) have an uncanny ability to regenerate their heads (students sometimes create two-headed planaria in science lab).  At MIT, Medical Xpress reported, scientists made the discovery that muscle cells in the flatworm have the ability to communicate with their nearby stem cells, informing them what kind of tissue is needed.  Certain “position control genes,” which are “highly conserved and many are found in other animals, including humans,” are controlled by particular proteins in the muscle cells.  When wounded, cells alter these proteins to control which PCGs are made, signaling pathways that direct the stem cells to know what kinds of repairs are needed.  “Because the muscle fibers are long, when you cut the animal, it can immediately respond by contracting to close the wound, turning on wound-induced genes at that site, and eventually changing the pattern of expression to respond to the missing tissue.”  Understanding that flow of information “opens whole new areas of research,” the article said.

It was just in time.  In 2007, when Japanese scientists learned how to create iPSCs from adult tissues (a Nobel prize discovery), they took the wind out of embryonic stem cell research.  Throughout the Bush and early Obama administrations, scientists were clamoring for rights to destroy human embryos in order to understand stem cells, pulling at the public’s heartstrings to claim patients were dying without them, because conservatives didn’t care about people.  Now that iPSCs and adult stem cells are plentiful and just as effective, why use ESCs at all?  Researchers can learn all they need to know about them from mice and zebrafish.  A subtext we hope you noticed in these stories is that many scientists today would prefer to avoid the ethical controversies.  They want to help patients “without having to resort to embryonic stem cells.”  That’s a welcome change of heart.

The miracle cures possible with adult stem cells and iPSCs are at the doorstep.  We have much to look forward to: new hearts, new teeth, new blood vessels and much more.  This will be healthy, morally good, practical research that has nothing to do with evolution.  We need more of that kind of science.

 

 

 

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