Stem Cell Research
Chat Highlights
October 6, 2004

Norma Devine, Editor

On Wednesday, October 6, 2004, Dr. Rick Wilson, a glaucoma specialist at Wills, and the glaucoma chat group discussed "Stem Cell Research."

Dr. Rick Wilson:  In the Proceedings of the National Academy of Sciences, a group of Stanford scientists reported finding that fetal brain cells may be capable of growing into neurons and filling gaps in the brain caused by strokes.  The researchers injected stem cells derived from fetal tissue into the brains of rats. The cells migrated to the injured location and turned into the appropriate kinds of neurons, repairing much of the damage from the stroke.

P:  Would it be possible for stems cells to replace damaged ganglion cells?  

Dr. Rick Wilson:  Stem cells have been injected onto retinas depleted of ganglion cells.  Not only have the stem cells replaced the ganglion cells, but their fibers have also grown back to the brain in the correct area, something that no one expected. That is a real step forward in the quest to replace retinal ganglion cells lost to glaucoma and thereby restore sight.

P:  The Israelis seem to be making progress in stem cell research.

Dr. Rick Wilson:  Yes, they have injected stem cells into the brains of rats and alleviated Parkinson's-like symptoms.  Another important finding was that the stem cells did not proliferate out of control, as had been seen in a U.S. trial.  That U.S. trial used human subjects.

P:  When do you think stem cell research might be applicable to human subjects?

Dr. Rick Wilson:  It is hard to tell.  I would expect some help in the 10 to 15 year window, but that is clearly a guess.  I've been impressed by the speed at which the English and Israelis are moving ahead.  If the California stem cell initiative passes and the New Jersey initiative is fully funded, that might accelerate things.  Obviously, the biggest help for government-sponsored stem cell research at the National Eye Institute would be a change in presidents.

P:  Do you think the Koreans will share their research findings with the rest of the world?  

Dr. Rick Wilson:  Yes.  Sorry I forgot to mention them. 

P:  Will there need to be any remaining sight or optic nerve for the stem cells to work?

Dr. Rick Wilson:  The optic nerve will need to be intact; that is, it should have no other serious injury except for the loss of nerve fibers from glaucoma.

P:  What if the optic nerve is badly damaged? 

Dr. Rick Wilson:  If the structure of the optic nerve is not damaged and only the nerve fibers have been killed by glaucoma, I am not sure how much difference it makes whether stem cells have to reproduce 20% of the nerve or 90% of the nerve.

P:  Does it make a difference if the research uses embryonic or adult stem cells?

Dr. Rick Wilson:  Yes.  Adult stem cells are limited in the cure of disease, because they can only become cells of the same type as those constituting the tissue they come from; for example, adult nerve stem cells can only become nerve or brain cells.

P:  You indicated that stem cells proliferated out of control in a trial in the U.S.  Would you talk about that, please?

Dr. Rick Wilson:  The major stumbling block to human experiments so far has not been getting fetal cells to differentiate into heart or brain tissue.  Rather, it has been that a few cells may grow out of control, becoming growths or tumors.  In the U.S. experiment, where stem cells were transplanted into the brains of volunteers with Parkinson's disease and underwent uncontrolled growth, too much dopamine was produced in the brains of 15% of the participants.  That resulted in side effects, such as jerking of the limbs.

P:  What about using stem cells from the umbilical cords of newborn babies?  

Dr. Rick Wilson:  That does seem to be a source of pleuripotential cells that can grow into most kinds of tissues.

P:  Is it conceivable to use a person's own cells for optic nerve regeneration?

Dr. Rick Wilson:  That is a very tantalizing possibility.  If a person's own cells are used to build a heart or pancreas, then there is no threat of rejection.

P:  Does the immune system need to be suppressed to prevent rejection of the cells?   

Dr. Rick Wilson:  No.  You do not reject your own cells.

P:  Then stem cell therapy, if successful, would not have the rejection problems of organ transplants.

Dr. Rick Wilson:  That is the key.

P:  Why are many doctors opposed to stem cell research?  I know they don't want to give false hope, but the real possibility of being able to improve the health of patients suffering from Huntington's disease by implanting stem cells is no longer the stuff of Star Trek.  

Dr. Rick Wilson:  I am sure they don't want to raise patients' expectations that a cure is around the corner.  However, the doctors I talk to are enthusiastic.  It will definitely take time to perfect.  However, before this there has not been any hope that vision lost to glaucoma could be restored.  I saw that 48 Nobel laureates support John Kerry because of his much more enlightened positions on everything from stem cell research to breast cancer to global warming.

P:  If stem cells could be transplanted in glaucoma patients, would the surgery be invasive or microscopic?  

Dr. Rick Wilson:  The surgery I have read about has been microscopic, with needles placing the stem cells in the area requiring cell replacement, mending, and healing.

P:  I'm somewhat surprised that attention is now drawn to stem cell research for treatment of optic nerve damage.  What causes damaging intraocular pressures or degeneration of the optic nerve isn't clear.  Couldn't the nerve be regenerated with stem cells and then fall prey to the same forces that caused the glaucoma in the first place?

Dr. Rick Wilson:  Clearly, using stem cells to regenerate a nerve should be reserved for patients with nerves that have been stabilized through medicine or surgery.

P:  How would optic nerve regeneration affect an eye that has had a trabeculectomy?  

Dr. Rick Wilson:  A trabeculectomy should not have any direct effect that I know of.

P:  Can stem cells be harvested now and frozen for use later when researchers have figured out how to use them? 

Dr. Rick Wilson:  I assume so, though they get freezer burn after a while and so may loose some of their attributes.

P:  I am really in favor of stem cell research.  I think our puritanical society needs to wake up and face reality.  Stem cells are really needed for so many terrible diseases. 

Dr. Rick Wilson:  Me, too.   Obviously, as a doctor I am pro life --  that is, my goal is to save lives and improve the lives of those with diabetes, Alzheimer's, Parkinson's, heart disease, spinal cord injury, strokes, etc.

Dr. Rick Wilson:  Good night everyone.  Thanks for your attention.

End of highlights for October 6, 2004.

On October 13, Dr. Wilson discussed "Factors for Surgical Intervention" in the Chat room. Click here for highlights of that meeting.

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