Published online 25 February 2009 | Nature | doi:10.1038/news.2009.121
News
'Harmless' prion protein linked to Alzheimer's disease Non-infectious form of prion protein could cause brain degeneration.
Heidi Ledford
Prion proteins may react with amyloid-ß peptides inside the brain cells of Alzheimer's patients.Thomas Deerinck NCMIR/Science Photo LibraryNon-infectious prion proteins found in the brain may contribute to Alzheimer's disease, researchers have found.
The surprising new results, reported this week in Nature1, show that normal prion proteins produced naturally in the brain interact with the amyloid-ß peptides that are hallmarks of Alzheimer's disease. Blocking this interaction in preparations made from mouse brains halted some neurological defects caused by the accumulation of amyloid-ß peptide. It was previously thought that only infectious prion proteins, rather than their normal, non-infectious counterparts, played a role in brain degeneration.
The results have yet to be confirmed in humans, but suggest that targeting the non-infectious prion protein (PrPc) could provide an alternative route to treating Alzheimer's disease. "The need is huge," says Paul Aisen, an Alzheimer's researcher based at the neurosciences department of the University of California, San Diego. "And it's great news for the field when a new idea is brought forth with strong evidence that can lead to new therapeutic strategies."
Proteins misbehaving Alzheimer's disease has long been linked to the build-up of amyloid-ß peptides, first into relatively short chains known as oligomers, and then eventually into the long, sticky fibrils that form plaques in the brain. The oligomeric form of the peptide is thought to be toxic, but exactly how it acts in the brain is unknown.
Stephen Strittmatter and his colleagues at Yale University in New Haven, Connecticut searched for brain cell proteins that interact with amyloid-ß oligomers. To their surprise, they found PrPc, the normal, non-infectious prion protein.
Normal prion proteins are produced naturally in the brain, but can cause disease when they come into contact with an infectious form of the protein (PrPSc) that folds into an unusual conformation. These infectious prions convert innocuous prion proteins into the infectious form, which forms clumps and leads to neurodegenerative diseases, such as variant Creutzfeldt-Jakob disease, the human form of mad cow disease.
Strittmatter's team found that in brain slices taken from mice that were engineered to lack the prion protein, amyloid-ß did not cause defects in a process called long-term potentiation, which is important for long-term memory formation. Similarly, using an antibody to block the prion protein also prevented damage caused by the errant amyloid-ß peptides.
Therapeutic potential Researchers have struggled to determine what prion proteins normally do in the brain. Mice that lack the protein appear largely normal, with possible minor deficits in the generation of new neurons and responses to stress. A recent study found evidence that the prion protein may also be necessary for mice to have a normal sense of smell2.
Nevertheless, the results in mice suggest that blocking the protein may have unwanted side-effects, says Lennart Mucke, a neurologist at the Gladstone Institute of Neurological Disease in San Francisco, California. Although some are already at work to develop drugs that target the prion protein, these programmes target the infectious form of the protein and may not be useful in warding off Alzheimer's disease.
But Strittmatter and his colleagues mapped the region of the prion protein that interacts with amyloid-ß, giving researchers a clear target in the search for inhibitors of this interaction. Mucke, meanwhile, points out that an enzyme called a-secretase can cleave the prion protein at a site that would prevent it from binding to amyloid-ß. This same enzyme can also cleave amyloid-ß itself, meaning that enhancing that enzyme's activity could yield two strikes against Alzheimer's disease.
Although more work needs to be done to confirm the results in animal and human studies, Aisen says Alzheimer's disease researchers will welcome a new target in the fight against the frustrating disease. Clinical trials are underway to test drugs that aim to reduce the levels of amyloid-ß in the brain, but researchers are pessimistic about ever driving amyloid-ß levels down to zero. Meanwhile, treatments already on the market target symptoms of the disease, and not it's underlying cause.
"The treatments we have for Alzheimer's disease today are symptomatic and entirely inadequate," says Aisen. "There's no question that we need treatments that target the mechanisms behind neurodegeneration in Alzheimer's disease."
References Lauren, J. et al. Nature 457, 1128-1132 (2009). Le Pichon, C. E. et al. Nature Neuroscience 12, 60-69 (2008). | Article | PubMed | ChemPort |
http://www.nature.com/news/2009/090225/full/news.2009.121.html
Link found between Alzheimer's, mad cow protein Bernadette Tansey, Chronicle Staff Writer
Thursday, February 26, 2009
(02-25) 19:56 PST -- The latest in a recent flurry of clues on the workings of Alzheimer's disease comes from Yale University researchers who found a link between the disorder and the prion protein, which can cause mad cow disease and other maladies.
The Yale team found that the prion protein, whose normal function is to maintain brain health, may contribute to nerve damage if it becomes entangled with a protein fragment that scientists consider a chief suspect as a cause for Alzheimer's disease.
That suspect fragment, the amyloid beta peptide, builds up in the gluey plaques in the brain that are a characteristic sign of Alzheimer's, a progressive neurodegenerative disease. The amyloid peptide seems to stick to the prion protein, block its benign effects and interfere with learning and memory, the Yale group said in a paper published Wednesday in the journal Nature.
'Very tantalizing' "It's very tantalizing," said Dr. Lennart Mucke, director of the Gladstone Institute of Neurological Disease, who wrote a commentary on the Yale theory in the same issue. Mucke is part of a robust community of Bay Area scientists who are trying to ferret out the root causes of Alzheimer's disease and develop new medicines.
The prion work adds to a spate of new leads produced at the Gladstone Institute at UCSF's Mission Bay campus, the Buck Institute for Age Research in Novato, South San Francisco biotechnology leader Genentech Inc. and other research teams.
The study by Dr. Stephen Strittmatter and his Yale colleagues raises the possibility of a link between Alzheimer's and the family of prion diseases that includes mad cow disease and a related human neurodegenerative illness called Creutzfeldt-Jakob disease. But the evidence so far shows no sign that Alzheimer's disease involves a prion protein with the deformed structure seen in mad cow and Creutzfeldt-Jakob disease. Such misfolded prions can arise from genetic mutations or can be carried into the body by infectious particles from tainted meat.
Mucke said that the prion protein, if it is involved in Alzheimer's, is probably in its normal form. There's no evidence that the disease somehow releases infectious prions. "I don't believe it's communicable," he said.
Other new theories The prion study does not contradict other new theories about Alzheimer's, which all suggest fresh potential mechanisms by which the amyloid peptide or its parent, a protein called APP, may wreak destruction on the brain, said Dr. Dale Bredesen of the Buck Institute. Each theory opens potential new avenues to experimental therapies, he said. So far, much of the drug discovery in Alzheimer's has been focused on simply clearing the amyloid peptide and its plaques from the brain, on the theory that they cause broad physical or chemical damage, Bredesen said. But new work shows that APP and the amyloid peptide are involved in sensitive signaling networks that can go awry and destroy healthy nerves.
"I think we're seeing a fundamental switch in the view of the disease," he said. Recent failures of experimental drugs aimed at the amyloid peptide alone suggest that additional tactics are needed, he said. "Amyloid beta was the tip of the iceberg, but there's more."
Bredesen has his own overarching theory. He sees APP as a molecular switch on the nerves that flips between health and destruction. The protein can split up into three parts that each nourish the nerve. Or it can fracture differently into four parts that each attack the nerve - and one of those destructive four is the amyloid peptide, he said.
Search for a therapy In the search for a possible therapy for Alzheimer's, Bredesen is focusing on a molecule that seems to block the destruction switch. The nerve growth factor netrin-1 appears to curb the release of the amyloid peptide from APP, he said. Work is under way on methods to deliver netrin-1 to people with early signs of Alzheimer's, but it could take five years to produce an approved drug, he said.
Mucke said the Gladstone Institute is working on an array of strategies, which include preventing the amyloid peptide from finding molecules that pass along its destructive signals.
Scientists are starting to see Alzheimer's as a complex disease like cancer or hypertension, which can arise from various root causes. That means patients may need a cocktail of several drugs, and maybe a custom-made mix for each individual.
"I'm absolutely convinced that different people get Alzheimer's for different reasons, and drug development will have to take that into account," Mucke said.
E-mail Bernadette Tansey at [email protected].
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2009/02/25/MNC7164VHL.DTL
> Mucke said that the prion protein, if it is involved in Alzheimer's, is probably in its normal form. There's no evidence
> that the disease somehow releases infectious prions. "I don't believe it's communicable," he said.
Greetings,
LOT of if's, probably's, and don't believe's still. BUT let's take a closer look at the old science i.e. transmission studies ;
IN STRICT CONFIDENCE
TRANSMISSION OF ALZHEIMER-TYPE PLAQUES TO PRIMATES
http://www.bseinquiry.gov.uk/files/yb/1993/01/05004001.pdf
Regarding Alzheimer's disease
(note the substantial increase on a yearly basis)
http://www.bseinquiry.gov.uk/files/yb/1988/07/08014001.pdf
snip...
The pathogenesis of these diseases was compared to Alzheimer's disease at a molecular level...
snip...
http://www.bseinquiry.gov.uk/files/yb/1990/03/12003001.pdf
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.
http://www.bseinquiry.gov.uk/files/yb/1990/07/06005001.pdf
Human BSE
snip...
These are not relevant to any possible human hazard from BSE nor to the much more common dementia, Alzheimers.
snip...
http://www.bseinquiry.gov.uk/files/yb/1990/07/09001001.pdf
CJD1/9 0185
Ref: 1M51A
IN STRICT CONFIDENCE
Dr McGovern From: Dr A Wight
Date: 5 January 1993
Copies: Dr Metters
Dr Skinner
Dr Pickles
Dr Morris
Mr Murray
TRANSMISSION OF ALZHEIMER-TYPE PLAQUES TO PRIMATES
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.
93/01.05/4.1tss
http://www.bseinquiry.gov.uk/files/yb/1993/01/05004001.pdf
BSE101/1 0136
IN CONFIDENCE
5 NOV 1992
CMO From: Dr J S Metters DCMO 4 November 1992
TRANSMISSION OF ALZHEIMER TYPE PLAQUES TO PRIMATES
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) the 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 clinical condition as the "animals were behaving normally when killed'. As the report emphasises the unanswered question is whether the disease condition would have revealed itself if the marmosets had lived longer. They are planning funher research to sec if the conditions, as opposed to the partial pathological process, is transmissible.
What are the implications for public health?
3. . The route of transmission is very specific and in the natural state of things 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 pathological process. Should therefore brain tissue from such cases be regarded as potentially infective? Pathologists, morticians, neuro surgeons and those assisting at neuro surgical procedures and others coming into contact with "raw" human brain tissue could in theory be at risk. However, on a priori grounds given the highly specific route of transmission in these experiments that risk must be negligible if the usual precautions for handling brain tissue are observed.
92/11.4/1-1
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 intra-cerebral 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 marmoset. 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 comfortable message, but until we know more about the causation of Alzheimer's disease the total reassurance is not practical.
JS METTERS Room 509 Richmond House Pager No: 081-884 3344 Callsign: DOH 832
121/YdeStss
92/11.4/1.2
http://www.bseinquiry.gov.uk/files/yb/1992/11/04001001.pdf
also, see the increase of Alzheimer's from 1981 to 1986
http://www.bseinquiry.gov.uk/files/yb/1988/07/08014001.pdf
IN STRICT CONFIDENCE
TRANSMISSION OF ALZHEIMER-TYPE PLAQUES TO PRIMATES
http://www.bseinquiry.gov.uk/files/yb/1993/01/05004001.pdf
Tuesday, August 26, 2008
Alzheimer's Transmission of AA-amyloidosis: Similarities with Prion Disorders NEUROPRION 2007 FC4.3
http://betaamyloidcjd.blogspot.com/2008/08/alzheimers-transmission-of-aa.html
SNIP... see full text ;
Thursday, February 26, 2009
'Harmless' prion protein linked to Alzheimer's disease Non-infectious form of prion protein could cause brain degeneration
http://betaamyloidcjd.blogspot.com/2009/02/harmless-prion-protein-linked-to.html
Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA 77518
News
'Harmless' prion protein linked to Alzheimer's disease Non-infectious form of prion protein could cause brain degeneration.
Heidi Ledford
Prion proteins may react with amyloid-ß peptides inside the brain cells of Alzheimer's patients.Thomas Deerinck NCMIR/Science Photo LibraryNon-infectious prion proteins found in the brain may contribute to Alzheimer's disease, researchers have found.
The surprising new results, reported this week in Nature1, show that normal prion proteins produced naturally in the brain interact with the amyloid-ß peptides that are hallmarks of Alzheimer's disease. Blocking this interaction in preparations made from mouse brains halted some neurological defects caused by the accumulation of amyloid-ß peptide. It was previously thought that only infectious prion proteins, rather than their normal, non-infectious counterparts, played a role in brain degeneration.
The results have yet to be confirmed in humans, but suggest that targeting the non-infectious prion protein (PrPc) could provide an alternative route to treating Alzheimer's disease. "The need is huge," says Paul Aisen, an Alzheimer's researcher based at the neurosciences department of the University of California, San Diego. "And it's great news for the field when a new idea is brought forth with strong evidence that can lead to new therapeutic strategies."
Proteins misbehaving Alzheimer's disease has long been linked to the build-up of amyloid-ß peptides, first into relatively short chains known as oligomers, and then eventually into the long, sticky fibrils that form plaques in the brain. The oligomeric form of the peptide is thought to be toxic, but exactly how it acts in the brain is unknown.
Stephen Strittmatter and his colleagues at Yale University in New Haven, Connecticut searched for brain cell proteins that interact with amyloid-ß oligomers. To their surprise, they found PrPc, the normal, non-infectious prion protein.
Normal prion proteins are produced naturally in the brain, but can cause disease when they come into contact with an infectious form of the protein (PrPSc) that folds into an unusual conformation. These infectious prions convert innocuous prion proteins into the infectious form, which forms clumps and leads to neurodegenerative diseases, such as variant Creutzfeldt-Jakob disease, the human form of mad cow disease.
Strittmatter's team found that in brain slices taken from mice that were engineered to lack the prion protein, amyloid-ß did not cause defects in a process called long-term potentiation, which is important for long-term memory formation. Similarly, using an antibody to block the prion protein also prevented damage caused by the errant amyloid-ß peptides.
Therapeutic potential Researchers have struggled to determine what prion proteins normally do in the brain. Mice that lack the protein appear largely normal, with possible minor deficits in the generation of new neurons and responses to stress. A recent study found evidence that the prion protein may also be necessary for mice to have a normal sense of smell2.
Nevertheless, the results in mice suggest that blocking the protein may have unwanted side-effects, says Lennart Mucke, a neurologist at the Gladstone Institute of Neurological Disease in San Francisco, California. Although some are already at work to develop drugs that target the prion protein, these programmes target the infectious form of the protein and may not be useful in warding off Alzheimer's disease.
But Strittmatter and his colleagues mapped the region of the prion protein that interacts with amyloid-ß, giving researchers a clear target in the search for inhibitors of this interaction. Mucke, meanwhile, points out that an enzyme called a-secretase can cleave the prion protein at a site that would prevent it from binding to amyloid-ß. This same enzyme can also cleave amyloid-ß itself, meaning that enhancing that enzyme's activity could yield two strikes against Alzheimer's disease.
Although more work needs to be done to confirm the results in animal and human studies, Aisen says Alzheimer's disease researchers will welcome a new target in the fight against the frustrating disease. Clinical trials are underway to test drugs that aim to reduce the levels of amyloid-ß in the brain, but researchers are pessimistic about ever driving amyloid-ß levels down to zero. Meanwhile, treatments already on the market target symptoms of the disease, and not it's underlying cause.
"The treatments we have for Alzheimer's disease today are symptomatic and entirely inadequate," says Aisen. "There's no question that we need treatments that target the mechanisms behind neurodegeneration in Alzheimer's disease."
References Lauren, J. et al. Nature 457, 1128-1132 (2009). Le Pichon, C. E. et al. Nature Neuroscience 12, 60-69 (2008). | Article | PubMed | ChemPort |
http://www.nature.com/news/2009/090225/full/news.2009.121.html
Link found between Alzheimer's, mad cow protein Bernadette Tansey, Chronicle Staff Writer
Thursday, February 26, 2009
(02-25) 19:56 PST -- The latest in a recent flurry of clues on the workings of Alzheimer's disease comes from Yale University researchers who found a link between the disorder and the prion protein, which can cause mad cow disease and other maladies.
The Yale team found that the prion protein, whose normal function is to maintain brain health, may contribute to nerve damage if it becomes entangled with a protein fragment that scientists consider a chief suspect as a cause for Alzheimer's disease.
That suspect fragment, the amyloid beta peptide, builds up in the gluey plaques in the brain that are a characteristic sign of Alzheimer's, a progressive neurodegenerative disease. The amyloid peptide seems to stick to the prion protein, block its benign effects and interfere with learning and memory, the Yale group said in a paper published Wednesday in the journal Nature.
'Very tantalizing' "It's very tantalizing," said Dr. Lennart Mucke, director of the Gladstone Institute of Neurological Disease, who wrote a commentary on the Yale theory in the same issue. Mucke is part of a robust community of Bay Area scientists who are trying to ferret out the root causes of Alzheimer's disease and develop new medicines.
The prion work adds to a spate of new leads produced at the Gladstone Institute at UCSF's Mission Bay campus, the Buck Institute for Age Research in Novato, South San Francisco biotechnology leader Genentech Inc. and other research teams.
The study by Dr. Stephen Strittmatter and his Yale colleagues raises the possibility of a link between Alzheimer's and the family of prion diseases that includes mad cow disease and a related human neurodegenerative illness called Creutzfeldt-Jakob disease. But the evidence so far shows no sign that Alzheimer's disease involves a prion protein with the deformed structure seen in mad cow and Creutzfeldt-Jakob disease. Such misfolded prions can arise from genetic mutations or can be carried into the body by infectious particles from tainted meat.
Mucke said that the prion protein, if it is involved in Alzheimer's, is probably in its normal form. There's no evidence that the disease somehow releases infectious prions. "I don't believe it's communicable," he said.
Other new theories The prion study does not contradict other new theories about Alzheimer's, which all suggest fresh potential mechanisms by which the amyloid peptide or its parent, a protein called APP, may wreak destruction on the brain, said Dr. Dale Bredesen of the Buck Institute. Each theory opens potential new avenues to experimental therapies, he said. So far, much of the drug discovery in Alzheimer's has been focused on simply clearing the amyloid peptide and its plaques from the brain, on the theory that they cause broad physical or chemical damage, Bredesen said. But new work shows that APP and the amyloid peptide are involved in sensitive signaling networks that can go awry and destroy healthy nerves.
"I think we're seeing a fundamental switch in the view of the disease," he said. Recent failures of experimental drugs aimed at the amyloid peptide alone suggest that additional tactics are needed, he said. "Amyloid beta was the tip of the iceberg, but there's more."
Bredesen has his own overarching theory. He sees APP as a molecular switch on the nerves that flips between health and destruction. The protein can split up into three parts that each nourish the nerve. Or it can fracture differently into four parts that each attack the nerve - and one of those destructive four is the amyloid peptide, he said.
Search for a therapy In the search for a possible therapy for Alzheimer's, Bredesen is focusing on a molecule that seems to block the destruction switch. The nerve growth factor netrin-1 appears to curb the release of the amyloid peptide from APP, he said. Work is under way on methods to deliver netrin-1 to people with early signs of Alzheimer's, but it could take five years to produce an approved drug, he said.
Mucke said the Gladstone Institute is working on an array of strategies, which include preventing the amyloid peptide from finding molecules that pass along its destructive signals.
Scientists are starting to see Alzheimer's as a complex disease like cancer or hypertension, which can arise from various root causes. That means patients may need a cocktail of several drugs, and maybe a custom-made mix for each individual.
"I'm absolutely convinced that different people get Alzheimer's for different reasons, and drug development will have to take that into account," Mucke said.
E-mail Bernadette Tansey at [email protected].
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2009/02/25/MNC7164VHL.DTL
> Mucke said that the prion protein, if it is involved in Alzheimer's, is probably in its normal form. There's no evidence
> that the disease somehow releases infectious prions. "I don't believe it's communicable," he said.
Greetings,
LOT of if's, probably's, and don't believe's still. BUT let's take a closer look at the old science i.e. transmission studies ;
IN STRICT CONFIDENCE
TRANSMISSION OF ALZHEIMER-TYPE PLAQUES TO PRIMATES
http://www.bseinquiry.gov.uk/files/yb/1993/01/05004001.pdf
Regarding Alzheimer's disease
(note the substantial increase on a yearly basis)
http://www.bseinquiry.gov.uk/files/yb/1988/07/08014001.pdf
snip...
The pathogenesis of these diseases was compared to Alzheimer's disease at a molecular level...
snip...
http://www.bseinquiry.gov.uk/files/yb/1990/03/12003001.pdf
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.
http://www.bseinquiry.gov.uk/files/yb/1990/07/06005001.pdf
Human BSE
snip...
These are not relevant to any possible human hazard from BSE nor to the much more common dementia, Alzheimers.
snip...
http://www.bseinquiry.gov.uk/files/yb/1990/07/09001001.pdf
CJD1/9 0185
Ref: 1M51A
IN STRICT CONFIDENCE
Dr McGovern From: Dr A Wight
Date: 5 January 1993
Copies: Dr Metters
Dr Skinner
Dr Pickles
Dr Morris
Mr Murray
TRANSMISSION OF ALZHEIMER-TYPE PLAQUES TO PRIMATES
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.
93/01.05/4.1tss
http://www.bseinquiry.gov.uk/files/yb/1993/01/05004001.pdf
BSE101/1 0136
IN CONFIDENCE
5 NOV 1992
CMO From: Dr J S Metters DCMO 4 November 1992
TRANSMISSION OF ALZHEIMER TYPE PLAQUES TO PRIMATES
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) the 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 clinical condition as the "animals were behaving normally when killed'. As the report emphasises the unanswered question is whether the disease condition would have revealed itself if the marmosets had lived longer. They are planning funher research to sec if the conditions, as opposed to the partial pathological process, is transmissible.
What are the implications for public health?
3. . The route of transmission is very specific and in the natural state of things 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 pathological process. Should therefore brain tissue from such cases be regarded as potentially infective? Pathologists, morticians, neuro surgeons and those assisting at neuro surgical procedures and others coming into contact with "raw" human brain tissue could in theory be at risk. However, on a priori grounds given the highly specific route of transmission in these experiments that risk must be negligible if the usual precautions for handling brain tissue are observed.
92/11.4/1-1
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 intra-cerebral 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 marmoset. 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 comfortable message, but until we know more about the causation of Alzheimer's disease the total reassurance is not practical.
JS METTERS Room 509 Richmond House Pager No: 081-884 3344 Callsign: DOH 832
121/YdeStss
92/11.4/1.2
http://www.bseinquiry.gov.uk/files/yb/1992/11/04001001.pdf
also, see the increase of Alzheimer's from 1981 to 1986
http://www.bseinquiry.gov.uk/files/yb/1988/07/08014001.pdf
IN STRICT CONFIDENCE
TRANSMISSION OF ALZHEIMER-TYPE PLAQUES TO PRIMATES
http://www.bseinquiry.gov.uk/files/yb/1993/01/05004001.pdf
Tuesday, August 26, 2008
Alzheimer's Transmission of AA-amyloidosis: Similarities with Prion Disorders NEUROPRION 2007 FC4.3
http://betaamyloidcjd.blogspot.com/2008/08/alzheimers-transmission-of-aa.html
SNIP... see full text ;
Thursday, February 26, 2009
'Harmless' prion protein linked to Alzheimer's disease Non-infectious form of prion protein could cause brain degeneration
http://betaamyloidcjd.blogspot.com/2009/02/harmless-prion-protein-linked-to.html
Terry S. Singeltary Sr. P.O. Box 42 Bacliff, Texas USA 77518