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From: TSS ()
Subject: Alzheimer’s may 'seed' itself like mad cow disease
Date: September 21, 2006 at 11:46 am PST

Alzheimer’s may 'seed' itself like mad cow disease
19:00 21 September 2006 news service
Roxanne Khamsi
Proteins taken from the brains of Alzheimer’s patients and injected into the brains of genetically engineered mice trigger Alzheimer’s-like lesions in the mouse brains, researchers report.
The findings suggest that the malformed protein clumps associated with Alzheimer’s disease can “seed” themselves in a way reminiscent of the missfolded proteins in prion diseases such as “mad cow” disease.

The exact causes of Alzheimer’s remain a mystery, but it appears that beta-amyloid proteins contribute to the formation of disruptive plaques in the brain. The neurological damage accumulates over years, causing loss of memory, language and other crucial mental skills.

Experts studying how beta amyloid might promote plaque formation have speculated that this might happen in a process similar to that in prion diseases.

Infectious agents
Prion illnesses, such as mad cow disease, are special in that proteins apparently act as the infectious agents, rather than genetic material or a microorganism. In laboratory tests, animals that receive prion proteins develop brain plaques and eventually die as a result.

Previous experiments have shown that injections of brain extracts from Alzheimer’s patients can trigger brain plaque formation in marmoset monkeys and mice.

But it has not been clear whether the beta-amyloid proteins themselves are responsible for this effect, or some other component of the brain tissue, says Lary Walker at Emory University in Atlanta, Georgia, US.

To investigate this, Walker's team used "APP23 mice" – genetically engineered to carry the human gene with a mutation that causes the animals to develop plaques in old age.

Seed hunting
When the young APP23 mice received brain extracts from either humans who had died with Alzheimer’s disease, or from older APP23 mice, the young mice developed brain plaques within weeks instead of the usual year.

Next, the team took brain extracts from old APP23 mice and exposed them to molecules that specifically bind and disable beta-amyloid proteins. When these treated extracts were injected into the brains of young mice, they did not cause the formation of plaques.

“For the first time we show that the likely seed is beta amyloid itself,” says Walker.

He notes that there is no evidence to suggest that beta amyloid alone can accelerate Alzheimer’s-like plaques in mice that are not genetically predisposed to the illness.

Walker adds that the evidence from the new experiment should encourage scientists to find out which forms of beta amyloid might promote plaque formation most aggressively in humans.

Journal reference: Science (DOI: 10.1126/science.1131864)

Subject: Transmissibility of mouse AApoAII amyloid fibrils: inactivation by physical and chemical methods
Date: March 22, 2006 at 6:31 am PST

The FASEB Journal Express Article doi:10.1096/
Published online March 20, 2006

Transmissibility of mouse AApoAII amyloid fibrils: inactivation by physical and chemical methods

Huanyu Zhang, Jinko Sawash!ta, Xiaoying Fu, Tatsumi Korenaga, Jingmin Yan, Masayuki Mori, and Keiichi Higuchi

E-mail contact:

AApoAII amyloid fibrils have exhibited prion-like transmissibility in mouse senile amyloidosis. We have demonstrated that AApoAII is extremely active and can induce amyloidosis following doses less than 1 pg. We tested physical and chemical methods to disrupt AApoAII fibrils in vitro as determined by thioflavin T binding and electron microscopy (EM) as well as inactivating the transmissibility of AApoAII fibrils in vivo. Complete disruption of AApoAII fibrils was achieved by treatment with formic acid, 6 M guanidine hydrochloride, and autoclaving in an alkaline solution. Injection of these disrupted AApoAII fibrils did not induce amyloidosis in mice. Disaggregation with 6 M urea, autoclaving, and alkaline solution was incomplete, and injection of these AApoAII fibrils induced mild amyloidosis. Treatment with formalin, delipidation, freeze-thaw, and RNase did not have any major effect. A distinct correlation was obtained between the amounts of amyloid fibrils and the transmissibility of amyloid fibrils, thereby indicating the essential role of fibril conformation for transmission of amyloidosis. We also studied the inactivation of AApoAII fibrils by several organic compounds in vitro and in vivo.

AApoAII amyloidosis provides a valuable system for studying factors that may prevent transmission of amyloid disease as well as potential novel therapies.

another transmissible protein amyloidosis? what does this implicate with Alzheimer's and TSE, if anything?.........TSS

CJD1/9 0185

Ref: 1M51A


Dr McGovern From: Dr A Wight

Date: 5 January 1993

Copies: Dr Metters

Dr Skinner

Dr Pickles

Dr Morris

Mr Murray


1. CMO will wish to be aware that a meeting was held at DH yesterday,
4 January, to discuss the above findings. It was chaired by Professor
Murray (Chairman of the MRC Co-ordinating Committee on Research in
the Spongiform Encephalopathies in Man), and attended by relevant
experts in the fields of Neurology, Neuropathology, molecular biology,
amyloid biochemistry, and the spongiform encephalopathies, and by
representatives of the MRC and AFRC.

2. Briefly, the meeting agreed that:

i) Dr Ridley et als findings of experimental induction of p amyloid
in primates were valid, interesting and a significant advance in the
understanding of neurodegeneradve disorders;

ii) there were no immediate implications for the public health, and no
further safeguards were thought to be necessary at present; and

iii) additional research was desirable, both epidemiological and at the
molecular level. Possible avenues are being followed up by DH
and the MRC, but the details will require further discussion.


BSE101/1 0136


5 NOV 1992

CMO From: Dr J S Metters DCMO 4 November 1992


1. Thank you for showing me Diana Dunstan's letter. I am glad that MRC have
recognised the public sensitivity of these findings and intend to report
them in their
proper context. This hopefully will avoid misunderstanding and possible
distortion by
the media to portray the results as having more greater significance than
the findings
so far justify.

2. Using a highly unusual route of transmission (intra-cerebral injection)
researchers have demonstrated the transmission of a pathological process
from two
cases one of severe Alzheimer's disease the other of Gerstmann-Straussler
disease to
marmosets. However they have not demonstrated the transmission of either
condition as the "animals were behaving normally when killed'. As the report
emphasises the unanswered question is whether the disease condition would
revealed itself if the marmosets had lived longer. They are planning funher
to sec if the conditions, as opposed to the partial pathological process, is

What are the implications for public health?

3. . The route of transmission is very specific and in the natural state of
highly unusual. However it could be argued that the results reveal a
potential risk,
in that brain tissue from these two patients has been shown to transmit a
process. Should therefore brain tissue from such cases be regarded as
infective? Pathologists, morticians, neuro surgeons and those assisting at
surgical procedures and others coming into contact with "raw" human brain
could in theory be at risk. However, on a priori grounds given the highly
route of transmission in these experiments that risk must be negligible if
the usual
precautions for handling brain tissue are observed.


BSE101/1 0137

4. The other dimension to consider is the public reaction. To some extent
the GSS
case demonstrates little more than the transmission of BSE to a pig by
injection. If other prion diseases can be transmitted in this way it is
little surprise that
some pathological findings observed m GSS were also transmissible to a
But the transmission of features of Alzheimer's pathology is a different
matter, given
the much greater frequency of this disease and raises the unanswered
question whether
some cases are the result of a transmissible prion. The only tenable public
line will
be that "more research is required" before that hypothesis could be
evaluated. The
possibility on a transmissible prion remains open. In the meantime MRC needs
carefully to consider the range and sequence of studies needed to follow
through from
the preliminary observations in these two cases. Not a particularly
message, but until we know more about the causation of Alzheimer's disease
the total
reassurance is not practical.

Room 509
Richmond House
Pager No: 081-884 3344
Callsign: DOH 832



Regarding Alzheimer's disease

(note the substantial increase on a yearly basis)


The pathogenesis of these diseases was compared to Alzheimer's disease at a
molecular level...


And NONE of this is relevant to BSE?

There is also the matter whether the spectrum of ''prion disease'' is wider
than that recognized at present.

Human BSE


These are not relevant to any possible human hazard from BSE nor to the much
more common dementia, Alzheimers.



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