Featured Research

from universities, journals, and other organizations

New models advance the study of deadly human prion diseases

Date:
August 19, 2013
Source:
Whitehead Institute for Biomedical Research
Summary:
By directly altering the gene coding for the prion protein (PrP), researchers have created mouse models of two neurodegenerative prion diseases, each of which manifests in different regions of the brain. These new models for fatal familial insomnia (FFI) and Creutzfeldt-Jakob disease (CJD) accurately reflect the distinct patterns of destruction caused by the these diseases in humans.

By directly manipulating a portion of the prion protein-coding gene, Whitehead Institute researchers have created mouse models of two neurodegenerative diseases that are fatal in humans. The highly accurate reproduction of disease pathology seen with these models should advance the study of these unusual but deadly diseases.

Related Articles


"By altering single amino acid codons in the gene coding for the prion protein, in the natural context of the genome -- no over expression or other artificial manipulations -- we can produce completely different neurodegenerative diseases, each of which spontaneously generates an infectious prion agent," says Whitehead Member Susan Lindquist. "The work irrefutably establishes the prion hypothesis."

According to the prion hypothesis, prion proteins infect by passing along their misfolded shape in templated fashion, unlike viruses or bacteria, which depend on DNA or RNA to transmit their information. Certain changes to the prion protein (PrP) create a misshapen structure, which is replicated by contact. The misfolded proteins accumulate, creating clumps that are toxic to surrounding tissue.

PrP is expressed at high levels in the brain, and prion diseases, including Creutzfeldt-Jakob disease (CJD) in humans, bovine spongiform encephalopathy (BSE, or "mad cow disease") in cows, and scrapie in sheep, wreak havoc on the brain and other neural tissues. Some prion diseases, like BSE, can be transmitted from feed animals to humans.

The study of these highly unusual but devastating prion diseases has to date been thwarted by a lack of animal models that faithfully mimic the disease processes in humans. However, Walker Jackson, a former postdoctoral researcher in Lindquist's lab is changing that, creating novel mouse models of human fatal familial insomnia (FFI) and CJD. His research is reported online this week in the Proceedings of the National Academy of Sciences (PNAS).

To generate the models, Jackson created two mutated versions of the PrP-coding gene by changing a single codon -- one of the three-nucleotide "words" in genes that code for the various amino acids in proteins. One mutation is known to cause FFI, while the other induces CJD. Unlike previous models that randomly inserted the mutations into the genome, occasionally increasing PrP expression, Jackson's models faithfully mimic the human disease -- from as to disease onset, to PrP production, to infectiousness. In the brain, his FFI mice develop neuronal loss in the thalamus and his CJD mice experience spongiosis in the hippocampus and the cerebellum, reflecting the damage seen in the brains of human patients.

"Walker (Jackson)'s work provides two extraordinary models of neurodegeneration," says Lindquist, who is also a professor of biology at MIT. "Most mouse models produce pathology that only distantly resembles human diseases. These nail it, for two of the most enigmatic human diseases in the world."

With the FFI and CJD models in hand, Jackson says he's excited to investigate how the pathology of these diseases develops.

"Now we have two interesting models that are selectively targeting specific parts of the brain: the thalamus in FFI and the hippocampus in CJD," says Jackson, who is now a Group Leader at the German Center for Neurodegenerative Disease. "But instead of focusing on areas that are heavily affected by the disease, we'll be looking at the areas that seem to be resisting the disease to see what they're doing. The protein is there, but for some reason, it's not toxic."

Initial characterization of one of the models (for FFI) was reporter earlier in Neuron.

This work is supported by the National Institutes of Health (NIH) and U.S. Department of Defense (DoD).


Story Source:

The above story is based on materials provided by Whitehead Institute for Biomedical Research. The original article was written by Nicole Giese Rura. Note: Materials may be edited for content and length.


Journal Reference:

  1. Walker S. Jackson, Andrew W. Borkowski, Nicki E. Watson, Oliver D. King, Henryk Faas, Alan Jasanoff, and Susan Lindquist. Profoundly different prion diseases in knock-in mice carrying single PrP codon substitutions associated with human diseases. PNAS, 2013 DOI: 10.1073/pnas.1312006110

Cite This Page:

Whitehead Institute for Biomedical Research. "New models advance the study of deadly human prion diseases." ScienceDaily. ScienceDaily, 19 August 2013. <www.sciencedaily.com/releases/2013/08/130819162519.htm>.
Whitehead Institute for Biomedical Research. (2013, August 19). New models advance the study of deadly human prion diseases. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2013/08/130819162519.htm
Whitehead Institute for Biomedical Research. "New models advance the study of deadly human prion diseases." ScienceDaily. www.sciencedaily.com/releases/2013/08/130819162519.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Mind & Brain News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Brain-Dwelling Tapeworm Reveals Genetic Secrets

Brain-Dwelling Tapeworm Reveals Genetic Secrets

Reuters - Innovations Video Online (Dec. 22, 2014) Cambridge scientists have unravelled the genetic code of a rare tapeworm that lived inside a patient's brain for at least four year. Researchers hope it will present new opportunities to diagnose and treat this invasive parasite. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Buzz60 (Dec. 19, 2014) A double-amputee makes history by becoming the first person to wear and operate two prosthetic arms using only his mind. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Prenatal Exposure To Pollution Might Increase Autism Risk

Prenatal Exposure To Pollution Might Increase Autism Risk

Newsy (Dec. 18, 2014) Harvard researchers found children whose mothers were exposed to high pollution levels in the third trimester were twice as likely to develop autism. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins