June 20, 2011 | David F. Coppedge

Stem Cell News

Stem cells continue to be hot subjects for research.  They are divided into two basic “political” parties: embryonic stem cells (ES), which raise ethical issues about tampering with human life, and adult stem cells (AS), found throughout the body, which have no ethical issues and show the most progress for therapy.  The latter include the induced pluripotent stem cells (iPS), coaxed from adult cells to recover the ability to differentiate into multiple tissue types.  Even though AS is leading, some scientists are still demanding federal funding for ES.

  1. Brains from iPS:  Work at Oxford produced neuron cells just like those in the brain from human skin, according to Medical Xpress.  “Each of the stages in the process – skin cells to iPS cells to nerve cells –  are visible under the microscope as they all look very different,” the article said.  “The clearly defined circular colony of stem cells gradually breaks up as nerve cells with their long thread-like projections appear, down which electrical signals can be transmitted.
  2. Short circuitScience Daily reported a new way to reprogram skin cells directly into brain cells, bypassing the need for stem cells altogether.  “The new technique avoids many of the ethical dilemmas that stem cell research has faced,” the article said, referring to fetal cells previously sought.  Direct reprogramming might make it possible to extract skin cells from a Parkinson’s patient and directly insert them into the brain.  The new technique also has the advantage of reducing the risk of tumor formation.
  3. Colon stem cells:  Researchers in the Netherlands are studying stem cell fate in the colon to determine the good guys from the bad guys that turn into colon cancer, reported Nature.
  4. Diseased stem cells:  A Stanford team found that iPS cells “accurately recapitulate features of a human stem cell disease and may serve as a cell-culture-based system for the development of targeted therapeutics.”  Published in Nature.
  5. Lung stem cellsPhysOrg reported how Duke scientists learned the signal used by airway stem cells to decide which tissues to become.  A participant declared, “Studies like ours will enhance efforts to develop effective genetic, cellular, and molecular therapies for airway diseases – a leading cause of death worldwide.”  Interestingly, the press release likened the Notch signalling pathway to “executive software” governing the stem cells’ fate.
  6. Fat stem cells:  Fighting a bulging waistline?  Then you might be interested in work at University of Texas trying to find ways to turn off the stem cells that add fat.  Read all about it at PhysOrg.
  7. Retina stem cellsPhysOrg reported that work at University of Wisconsin-Madison was able to produce retinal cells from both ES and iPS cells, creating a kind of “retina in a dish.”  It wasn't clear that the ES cells provided any advantage; one researcher called it “remarkable to think that something resembling the retina, one of the most specialized tissues in the human body, may one day be generated from a person’s skin.”
  8. Nose stem cells:  A new source of stem cells has been found in the mesenchymal tissues of the nose, reported PhysOrg.  The article conflated ethical qualms, saying, “Ethical and technical issues have so far limited clinical development of therapeutic approaches using ES and iPS cells, respectively, meaning that researchers are seeking alternative stem cell sources.”  It appears the word “respectively” assigns the ethical issues to ES, and the technical issues to iPS.
  9. Umbilical harvest:  An article on Science Daily shows a researcher at Johns Hopkins with a plastic gadget that promises to increase the harvest of stem cells from umbilical cord blood.  Maternity wards, where placentas have previously been discarded as medical waste, are becoming gold mines for stem cells.  The new device yields 50% more stem cells than previous methods – important for adult patients who need a lot of them.
  10. Bone marrow stem cells:  A paper in PLoS One found that first-generation stem cells from bone marrow are best.  By the 5th generation, protein expression profiles have changed.  The 1st generation cells “may be an effective therapeutic strategy for cardiac tissue regeneration” following acute myocardial infarction.

Work continues comparing ES and iPS cells, as this paper on PLoS One shows.  Apparently they are not identical, but pretty close.  PhysOrg had a strange way of arguing for maintenance of federal funding of ES: reducing it would impair work on iPS.  “"If federal funding stops for human embryonic stem cell research, it would have a serious negative impact on iPS cell research,” an ethicist from Stanford claimed. “We may never be able to choose between iPS and ES cell research because we don't know which type of cell will be best for eventual therapies.”

If researchers want to study ES cells, they can use mice, like these Aussies did in a paper on PLoS One.  There is no compelling reason to cut up human embryos for research.  There is certainly no reason to force taxpayers to fund it.  The momentum remains on the side of AS and iPS cells; if therapy is the goal, go ethically where the evidence leads.

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