29 March 2005

The Nose Knows . . . Stem Cells!

"And the nose [pause] has been cloned!" Miles Monroe (Woody Allen), Sleeper, 1973

For several years neuroscientists have been exploring the use of the stem cells found in the nose to help address injury and disease. Currently several teams of scientists are competing to develop clinical methods to help paralyzed patients.

[See update on success in pet dogs, below.]

The olfactory mucosa is one of the few sites where adults continue to grow new nerve cells from stem cells. Smell receptors can quickly regenerate after a cold or other damage. Professor Alan Mackay-Sim, deputy director of the Institute for Cell and Molecular Therapy at Griffith University, Queensland, has been studying smell and the unique properties of the cells he found in the nose for years. His team has been studying potential use of olfactory stem cells in treating Parkinson’s disease and is using stem cells from Parkinson’s sufferers to investigate the causes of Parkinson's.

Since nasal stem cells are abundantly available in a patient's own nose, concerns about transplant rejection are minimal, and no cultured stem cells from anyone's embryo are needed.

According to Mackay-Sim,
Our goal is to repair the brain and spinal cord by taking small pieces of tissue from the nose and transplanting these cells back into the same person in a manner similar to a skin graft. The cells could be grown in a dish to expand their numbers or they could be genetically engineered to cause them to express therapeutic molecules. The nose is the only place where neurons, and their associated cells, are easily accessible. Nasal transplants would overcome many ethical issues associated with cell therapy, such as the use of embryonic cells. [source]
Dr. Geoffrey Raisman and his team at University College London have experimented with rats, using nasal stem cells to repair spinal injuries. Dr Carlos Lima at the Egaz Moniz Hospital in Lisbon has performed similar operations on dozens of human patients.

Neural crest stem cells are another type of embryonic stem cell that persist into adulthood in hair follicles. Maya Sieber-Blum of the Medical College of Wisconsin and Milos Grim of Charles University Prague have previously shown that follicles might provide stem cells for some types of cell replacement therapy. (Abstract of a report of their work.)

The team at Griffiths University in Queensland, Australia, recently announced results of research where they transplanted cells from the olfactory mucosa of humans, rats, and mice in to chicken embryos. They demonstrated the cells can give rise not only to nerve cells but also to heart, liver, kidney, and muscle cells. A paper on their work is to be published online this week in Developmental Dynamics. “Multipotent stem cell in adult olfactory mucosa”, Wayne Murrell et al. (Abstract here. Subscription required for full text.)

This announcement got a lot of ink, partly because it comes in the middle of a debate in Australia about the legality of embryonic stem cell research, and partly because the research was partly funded by the Catholic Archdiocese of Sydney. Naturally anything about stem cells becomes political these days.

Dr. Murrell has said he hopes the findings will help advance adult stem cell research. "It's not that they can do more than the bone marrow or brain stem cells; it's just that, we hope, they will be easier to work with."

The citizens of California have recently committed to tax themselves $6 billion to establish a stem cell research center and sponsor stem cell research in their state, since the U.S. federal government has stopped funding research using embryonic stem cell lines.

If, as seems increasingly likely, use of embryonic stem cells turns out to be a minor detour on the road to effective stem cell therapies, and the National Institutes of Health and other federal funding agencies get back in the act, will the California program reap the benefits its backers have promised?

Here is the web site of The California Institute for Regenerative Medicine.

[Update 2012-11-19: Recent work with pet dogs suggests that some degree of paralysis can be partly overcome by transplantation of cloned olfactory sheathing cells from the lining of the nose to sites of spinal lesion. BBC article on the research here. We always knew dogs had good noses, but we didn't know everything they were good for! Enjoy the video in the BBC item.]

[ITN video of successful spinal cord repair in Guardian item here.]

Further Reading:

This site describes research at Griffith U. Queensland Australia

Here are some images of the olfactory epithelium and its stem cells from Thomas Schoenfeld's site at University of Massachusetts.

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1 comment:

Anonymous said...

I am anxious to hear about further success on stem cell research. A young friend of mine is tetraplegic due to an accident about two years ago. Now he has hope. Please hurry up research.Many thousands are waiting. God bless.