Cloning for brain repair in mice.
NEW YORK, March 23, 2008—Research led by investigators at Memorial Sloan-Kettering Cancer Center (MSKCC) has shown that therapeutic cloning, also known as somatic-cell nuclear transfer (SCNT), can be used to treat Parkinson’s disease in mice. The study’s results are published in the March 23 online edition of the journal Nature Medicine.
For the first time, researchers showed that therapeutic cloning or SCNT has been successfully used to treat disease in the same subjects from whom the initial cells were derived. While this current work is in animals, it could have future implications as this method may be an effective way to reduce transplant rejection and enhance recovery in other diseases and in other organ systems.
In therapeutic cloning or SCNT, the nucleus of a somatic cell from a donor subject is inserted into an egg from which the nucleus has been removed. This cell then develops into a blastocyst from which embryonic stem cells can be harvested and differentiated for therapeutic purposes. As the genetic information in the resulting stem cells comes from the donor subject, therapeutic cloning or SCNT would yield subject-specific cells that are spared by the immune system after transplantation.
The new study shows that therapeutic cloning can treat Parkinson’s disease in a mouse model. The scientists used skin cells from the tail of the animal to generate customized or autologous dopamine neurons—the missing neurons in Parkinson’s disease. The mice that received neurons derived from individually matched stem cell lines exhibited neurological improvement. But when these neurons were grafted into mice that did not genetically match the transplanted cells, the cells did not survive well and the mice did not recover.
This work builds on earlier work by the same team where they didn't make stem cells for each target animal. With this latest work they avoided the immune rejection problem that by starting with a genome from the target animal and then creating embryonic stem cells with that animal's genome.
Some religious people find cloning to create embryonic stem cells morally unacceptable because an embryo gets destroyed in the creation of the stem cells in most cases. But for a moment leave aside the ethical objections for use of this procedure with humans. The fact remains that given immune compatible cells properly prepared to become dopamine neurons it is possible to do brain repair and a limited form of brain rejuvenation.
Some see rejuvenation therapies as distant prospects. But I do not see why stem cell therapies lie only in the distant science fiction future. A therapy that works for mice today is going to work for humans within a timespan quick enough for many of us alive today.
| Share | | Randall Parker, 2008 March 25 10:56 PM Brain Stem Cells |
Here is a poll on when we will reach Actuarial Escape Velocity.
I notice that there is no prediction year indicated in the article, so even the optimists are hedging.
I voted before I saw the results of others. Turns out I chose the most popular range: 2030-2040.
I realize thinking about this question that I need to figure out which rejuvenation therapies are needed in order to reach AEV. We do not need them all to reach it. Some of them can come along 5-10-20 years later.
AEV will happen at different times for different people.
Rich people will have it sooner than poor people, all else being equal.
People who exercise and eat mostly fruits/vegetables will achieve it sooner than those who smoke, those who eat unhealthy foods, don't get check-ups, etc.
"when these neurons were grafted into mice that did not genetically match the transplanted cells, the cells did not survive well and the mice did not recover"
Interesting...I thought there was very little immune rejection in the brain. I know human cells have been transplanted into mice brains without provoking rejection. I thought the transplanted cells often died because they didn't integrate properly with the existing neural tissue. I.e., either too little or too much stimulation from neighboring neurons or glia cells.
Before folks here let their unbridled optimism run away too far, let's see where that somatic-cell nuclear transfer (SCNT) method transfers cell matter into.
No one frets about the harvesting of egg cells to be used in SCNT procedures; well no one except members of the PETA religion, anyway. (If you want to see a truly threatening religious objection, go wear fur to a PETA rally.) Now, about the millions of human egg cells that are going to be needed just to do the cell cloning research -- never mind any commercialized protocols made available to America's multitude of millionaires -- where will they come from?
Adult stem cells are being harvested and used in real therapies today because they're much less likely to flip into cancer cells. Instead of chasing down the chimera of embryonic stem cells, why not tell us more about using adult stem cells with the same protocols? Which one's working better? Oh look, a similar experiment was already done using adult cells and, according to the article, we should be seeing human trials in 2008. Anybody have anything fresher than 2005?
Randall Parker said “Some see rejuvenation therapies as distant prospects. But I do not see why stem cell therapies lie only in the distant science fiction future. A therapy that works for mice today is going to work for humans within a timespan quick enough for many of us alive today.”
Another strategy for rejuvenating the aged brain is described in an article at Medical News Today entitled The Aging Brain Helped by Injection of Human Umbilical Cord Blood. Here is an excerpt:
When human umbilical cord blood cells (UCBC) were injected into aged laboratory animals, researchers at the University of South Florida (USF) found improvements in the microenvironment of the hippocampus region of the animals' brains and a subsequent rejuvenation of neural stem/progenitor cells.The journal article appeared in BMC Neuroscience, an open access journal. Here is a link to the article titled Peripheral injection of human umbilical cord blood stimulates neurogenesis in the aged rat brain A large blood bank might allow for close immunological matching for treatment. Alternatively blood for a patient could be harvested at birth and stored. Or alternatively adult cells might be reprogrammed to act like the stem cells found in umbilical cord blood or something even better.
My question is whether these babies are best named "embryonic stem cells" or merely "totipotent stem cells". I.e., were they taken from human embryos, or merely cells taken from humans and converted to totipotency using one of the two recently announced techniques? If the latter, they're not "embryonic" in the sense that led to the current US policy.
Garson,
Stem cells to repair blood vessels would do a lot to slow brain aging. Part of the loss of brain cells is due to lots of small blockages in the brain's circulatory system. People tend to focus on the neurons. But we've got other cells involved in brain metabolism that we can repair and replace to reduce the damage caused as the brain ages.
michael i,
I am optimistic that stem cell researchers will find ways to turn adult cells into totipotent stem cells. I do not think we will keep needing to go thru the step cloning with eggs.
Are you suggesting AEV by 2040 for a decrepit old 120 year old, or only for people who's health is still in relatively good shape?
I will only be 61 by 2040, so I guess that will be middle aged (or less) by then, but I have a health problem so I would need more repair than others.