How promising is the idea of stem cells for Alzheimer’s Disease?
Alzheimer’s Disease (AD) is one of the most devastating illnesses that the human race has ever faced. It literally destroys the brain, which shrinks as a result over time (see image at left from Wikipedia).
The toll of AD is not only measured in hundreds of billions of dollars in health care costs and millions of deaths, but also in personal and family tragedy that comes with the severe loss of memory that accompanies it.
Remarkably, scientists and doctors are getting good at predicting who has pre-clinical AD or who will ultimately get AD before patients are even symptomatic. But is knowing of any good if we can’t do much about it?
How can AD be prevented or treated?
The simple answer is that nobody really knows.
However, a number of avenues provide hope for the future.
For example, the NYT has an article on a new clinical trial on a Columbian family that has a striking genetic predisposition to AD testing an antibody-based drug called Crenezumab, which has as its target the distinctive plaques that form in the AD brain even before the disease becomes clinically apparent. Many other drugs are being developed as well, but an overriding challenge is that, as mentioned above, we do not truly understand AD in the same way that we understand other diseases. Thus, further research is essential.
Another possible avenue to treat AD is through cellular or stem cell-based regenerative medicine therapies. I discussed this notion a year and a half ago in my blog’s disease focus series, and I suggest reading that as it provides key background.
There are three key possible approaches to using stem cells to treat AD.
1) One avenue is to use stem cells to regenerate or literally regrow diseased parts of the brain. This is what people most commonly think of when they conceive of treating AD with stem cells. The problem with this approach is that the architecture of the brain is physically integral to memory so even if we could grow a fresh, young part of the brain to replace one ravaged by AD, there would be no memories there. It would be like wiping the plate clean. In theory perhaps the person could make new memories going forward in life that could be remembered or they could be re-educated, but this is not what most people imagine as a successful treatment for AD.
2) Another approach is to use stem cells such as mesenchymal stem cells (MSC) not as rebuilding agents, but rather as healers of the existing brain parenchyma. In this way of thinking, MSC could heal rather than replace neurons for example. MSC are kind of akin to the natural doctors of the body and could have anti-inflammatory and other powers that might ameliorate AD.
3) A third concept is using stem cells such as MSC as drug delivery agents. So for example, instead of giving Crenezumab or some other drug systemically, it is possible that stem cells could directly deliver the drug within the brain from cell-to-cell far more effectively.
Some of these same kinds of approaches might be applicable to other diseases as well.
For more info on using stem cells to treat other diseases here are links to posts in my disease focus series below.
Cancer Stem Cells: a new target
Disease Focus Series: HIV/AIDS
Disease Focus Series: Spinal Cord Injury
Disease Focus Series: Osteoarthritis research moving forward
Disease Focus Series: Parkinson’s Disease and promising new pre-clinical results from iPS cells
Disease Focus Series: a big week of exciting progress on Alzheimer’s Disease
Disease Focus Series: Huntington’s Disease, a major new finding
The problem with beta-amyloid targetting methods is that the way it looks their role in the pathology is less significant than that of tau spindles….