Alzheimer's brain cells grown from skin cells of Down's syndrome patients

A friend of mine shared this article with me today from a biotech newsletter they received. I thought it was a pretty interesting article and seemed worthy of posting here.

Something that kind of stood out in my mind was that the study used down syndrome volunteers. I wondered how they were able to attain the proper "informed consent" from these down syndrome volunteers. I know that there are some relatively intelligent people with down syndrome out there. However I also know that there are many people with down syndrome who do not have the mental capacity to fully understand a voluntary consent form.

Perhaps they got the consent from a parent or legal guardian. There probably wasn't much risk involved for the volunteers and I'm assuming they just took the skin samples and that was all that was needed. But still I always wonder if these volunteers for these studies (not just this study) truly are properly informed of the risks involved.

Sounds like a worthy study. But I wonder, can these scientists also use these volunteers skill cells for other purposes too now? I would like to hear some other peoples opinion on this study. What are your thoughts?

Source

Skin cells from volunteers with Down's syndrome have been turned into brain cells in order to provide a new model for researchers to study Alzheimer's disease.

People with Down's syndrome are at high risk of developing Alzheimer's disease and show the first signs of the disease around 40 years earlier than those in the general population. To try and understand why this is, Cambridge University, where this research took place, has also launched a separate £1 million brain imaging study.

In the current study, published in , researchers used a two-step process to turn volunteers' skin cells into brain cells with Alzheimer's disease. The skin cells were first transformed into induced pluripotent stem (iPS) cells, which can be made to turn into almost any cell type in the body. Here, the iPS cells were turned into nerve cells which behaved identically to cells in the human brain.

After being grown for a short period of time in the lab, the newly-created cells showed all the characteristics of brain cells taken from Alzheimer's disease patients post-mortem. It is hoped that the cells will therefore provide an easier way for researchers to study how the disease starts and progresses.

Alzheimer's disease can take years or even decades to develop. As Dr Rick Livesey, who led the current study, said: 'One of the biggest challenges facing dementia researchers at the moment is a lack of good ways to track the disease over time. By using stem cells donated from people with Down's syndrome, we have been able to track how the disease develops over a shorter time period than has been possible in the past'.

Study Abstract

That the brains of Down Syndrome individuals get tangled fibrils in their neurons, the same as Alzheimer's patients, has been known for at least 30 years. I remember learning about this while studying biological psychology back in the 1980s. The interesting part is taking the cells of Down Syndrome folks and turning their skin cells into neurons with the help of stem cells.

I'm fairly certain that the legal guardians of the Down Syndrome patients gave their consent, in order to understand this phenomenon. The saddest thing about Down Syndrome is that these beautiful souls die so young, for it is programmed in their DNA to do so.

I look forward to what the results of this study will be, because although Down Syndrome is a DNA mutation, I believe that Alzheimer's is caused by environmental poisoning. What is the link?

Thanks for sharing!

reply to post by FissionSurplus


Thanks for your response and input. I agree with your assessment,

Really, I'm completely ignorant about these kinds of studies.

But, I'm interested in the results as well.

I thought I'd just toss in a little conspiracy aspect for the heck of it .... lol


www.bionews.org.uk...

stm.sciencemag.org...

Beyond the notion of proper consent, I do not see the ethical dilemma.

reply to post by ThirdRock69


Your ethics concerns are legitimate in general, if not with this specific study - there is a history of foster and otherwise compromised children being abused in various studies. Some of these cases have been discussed on ATS and many more have been all over the Internet. Oddly, none of my searches pull any results on ATS or Google. Here are the only two links I've managed to retrieve, which can be interpreted as representing policy on the issue:
Children and Clinical Studies: No More Hand-Me-Down Research
Terms You Should Know: Informed Consent

reply to post by FissionSurplus

….although Down Syndrome is a DNA mutation, I believe that Alzheimer's is caused by environmental poisoning. What is the link?

Good question. …Both diseases involve mutations in the amyloid protein (as do other diseases) - in Down's, the protein mutation results from a gene mutation, but in most Alzheimer's cases, the protein mutation is "sporadic" and epigenetic, not genetic.

In simple terms, epigenetic diseases involve mutated proteins, which can be inherited, but which do not involve DNA mutations, while genetic diseases result from actual gene mutations. Down's is accepted as genetic, but some researchers are looking at the role epigenetics might play in Down's - other researchers are looking at cases where Alzheimer's may be transmitted genetically rather than epigenetically or acquired (direct infection).

One of the better known mechanisms of epigenetic change is the prion - well-recognized as causing disease that is sporadic (epigenetic changes caused by environmental trigger), familial (inherited either epigenetically or genetically), and acquired (known environmental source of infection).

Prion diseases are unique transmissible neurodegenerative diseases that have diverse phenotypes and can be familial, sporadic, or acquired by infection. …

[It appears that some (many?) diseases start out as environmentally-induced epigenetic disorders, before modifying DNA and becoming genetic if they are deemed "successful."
NOTE: Epigenetic changes seem only to become permanent (modify DNA) if there is a clear beneficial effect in evolutionary terms.
ALSO NOTE: Prion-related disease is currently defined as only neurodegenerative however, cutting edge research is looking at the paths prions take to get from the gut or other points of entry to the brain, and at other diseases they may cause along the way.]

Professor Benjamin Tycko "Epigenetics and DNA methylation in Down syndrome"

Roger Reeves: Mouse models of epigenetics

Dr. Reeves studies specific changes in the craniofacial skeleton that are largely responsible for the characteristic facial appearance in Down syndrome and contribute to sleep apnea and other clinical presentations. The Reeves laboratory has traced these changes to the cells of origin, the neural crest. He is helping the Feinberg lab test its stochastic epigenetic plasticity model in mice, and he is working with Dr. Reddy on nuclear structure in Down syndrome.

More on epigenetics.

EPIGENETICS AND INHERITANCE

We used to think that a new embryo's epigenome was completely erased and rebuilt from scratch. But this isn't completely true. Some epigenetic tags remain in place as genetic information passes from generation to generation, a process called epigenetic inheritance.

Epigenetic inheritance is an unconventional finding. It goes against the idea that inheritance happens only through the DNA code that passes from parent to offspring. It means that a parent's experiences, in the form of epigenetic tags, can be passed down to future generations.

As unconventional as it may be, there is little doubt that epigenetic inheritance is real. In fact, it explains some strange patterns of inheritance geneticists have been puzzling over for decades.

........cont'd

……….cont'd from above

Epigenetic Influences and Disease

The external environment's effects upon genes can influence disease, and some of these effects can be inherited in humans. …

What Is Epigenetics? How Do Epigenetic Changes Affect Genes?

Epigenetics involves genetic control by factors other than an individual's DNA sequence. Epigenetic changes can switch genes on or off and determine which proteins are transcribed.

Epigenetics is involved in many normal cellular processes. Consider the fact that our cells all have the same DNA, but our bodies contain many different types of cells: neurons, liver cells, pancreatic cells, inflammatory cells, and others. How can this be? In short, cells, tissues, and organs differ because they have certain sets of genes that are "turned on" or expressed, as well as other sets that are "turned off" or inhibited. Epigenetic silencing is one way to turn genes off, and it can contribute to differential expression. Silencing might also explain, in part, why genetic twins are not phenotypically identical. In addition, epigenetics is important for X-chromosome inactivation in female mammals, which is necessary so that females do not have twice the number of X-chromosome gene products as males (Egger et al., 2004). Thus, the significance of turning genes off via epigenetic changes is readily apparent.

Within cells, there are three systems that can interact with each other to silence genes: DNA methylation, histone modifications, and RNA-associated silencing…

Alzheimer's, Down's and amyloid protein.

A mutation in the amyloid precursor protein associated with hereditary Alzheimer's disease

….Although most cases of Alzheimer's disease are sporadic, kindreds with autosomal-dominant inheritance of the syndrome suggest that a single mutation may be important in pathogenesis. Direct sequencing of DNA from a family with autopsy-proven Alzheimer's disease revealed a single amino acid substitution (Phe for Val) in the transmembrane domain of the amyloid precursor protein. This mutation correlates with the presence of Alzheimer's disease in all patients in this study, and may be the inherited factor causing both amyloid fibril formation and dementia.

What Is the Role of Genetics in Familial Alzheimer's Disease?

Alzheimer's disease strikes early and fairly often in certain families, often enough to be singled out as a separate form of the disease and given a label: early-onset familial Alzheimer's disease, or FAD. Combing through the DNA of these families, researchers have found an abnormality in one gene on chromosome 21 that is common to a few of the families. And they have linked a much larger proportion of early-onset families to recently identified and related genes on chromosomes 1 and 14.

The chromosome 21 gene also intrigues Alzheimer's researchers because of its role in Down syndrome. People with Down syndrome have an extra copy of chromosome 21 and, as they grow older, usually develop abnormalities in the brain like those found in Alzheimer's disease.

Few researchers think that the search for Alzheimer's genes is over. Most investigators are convinced that there are many more genes involved in Alzheimer's disease and, moreover, that other conditions must also be present for the disease to develop. One of these conditions may be a problem with the way in which nerves turn sugar, or glucose, into energy, a process known as glucose metabolism.

Mutation of the Alzheimer's disease amyloid gene in hereditary cerebral hemorrhage, Dutch type

An amyloid protein that precipitates in the cerebral vessel walls of Dutch patients with hereditary cerebral hemorrhage with amyloidosis is similar to the amyloid protein in vessel walls and senile plaques in brains of patients with Alzheimer's disease, Down syndrome, and sporadic cerebral amyloid angiopathy. ...