Tuesday, August 1, 2017

Could diabetes spread like mad cow disease?

Could diabetes spread like mad cow disease? 

By Mitch LeslieAug. 1, 2017 , 9:00 AM 

Prions are insidious proteins that spread like infectious agents and trigger fatal conditions such as mad cow disease. A protein implicated in diabetes, a new study suggests, shares some similarities with these villains. Researchers transmitted diabetes from one mouse to another just by injecting the animals with this protein. The results don’t indicate that diabetes is contagious like a cold, but blood transfusions, or even food, may spread the disease.

The work is “very exciting” and “well-documented” for showing that the protein has some prionlike behavior, says prion biologist Witold Surewicz of Case Western Reserve University in Cleveland, Ohio, who wasn’t connected to the research. However, he cautions against jumping to the conclusion that diabetes spreads from person to person. The study raises that possibility, he says, but “it remains to be determined.”

Prions are misfolded proteins that can cause normally folded versions of the same protein to misfold themselves. When this conversion occurs in the brain, the distorted proteins bunch up inside cells and kill them. Although prion diseases are rare in people, they share some similarities with more common illnesses. In Alzheimer’s disease, for instance, globs of a misshapen protein known as β amyloid build up in the brain. Parkinson’s disease and Huntington disease, two other brain maladies, also feature aggregates, or lumps of misfolded proteins.

At first glance, type 2 diabetes, in which people lose the ability to control their blood glucose levels, doesn’t seem to have any connection to prions or neurodegenerative diseases. But in people who have this form of diabetes, cells of the pancreas amass clumps of a protein known as islet amyloid polypeptide (IAPP), which is very similar to the β amyloid that accumulates in Alzheimer’s disease. Deposits of the protein may eventually kill many of the β cells in the pancreas that manufacture the hormone insulin.

In the new study, neurobiologist and biochemist Claudio Soto of McGovern Medical School at the University of Texas Health Science Center in Houston and colleagues tested whether IAPP alone could instigate diabetes in mice. The researchers began by culturing pancreatic cells from healthy humans and from young mice that had been genetically engineered to synthesize large amounts of human IAPP. When the scientists added material from the pancreases of old engineered mice that already had diabetes, clumps of IAPP sprouted in the cultured cells. The clumps also appeared when the cells were exposed to lab-synthesized IAPP tangles, the scientists report online today in The Journal of Experimental Medicine.

Soto and his team next tested whether they could induce IAPP clumps to form in live mice. Young rodents that had been genetically modified to crank out human IAPP are normally healthy, but when the scientists injected them with synthetic IAPP or with material from the pancreases of diabetic mice, IAPP conglomerations formed in the pancreas. As with prions, a smidgen of misfolded IAPP acts like a seed that spurs new clusters of the abnormal protein to grow.

The scientists then investigated whether inducing IAPP conglomerations in mice sparked the symptoms of type 2 diabetes. It did. The affected animals’ blood glucose concentrations were higher than those of control animals. And like people with diabetes, the animals had abnormal glucose tolerance tests, which measure their ability to metabolize a dose of the sugar. Even more striking, large numbers of β cells died in each rodent’s pancreas.

“We can induce the full-blown disease just by administering these protein aggregates” Soto says. He hastens to add that the results do not mean that diabetes can be transmitted through everyday interactions among people. “It’s not like the flu.” However, he says, the researchers plan to test whether the disease spreads through the routes followed by traditional prions, such as blood transfusions or organ transplants. Soto says that people might also be exposed to the potential diabetes trigger in food, for example, if they ate meat from animals whose pancreases had begun to accumulate IAPP.

Biochemist and cell biologist David Harris, who studies prions at Boston University School of Medicine, thinks the possibility of transmission between people is “overstated.” He says that the researchers transmitted the disease through artificial means, such as the injection of pancreas extracts from mice with diabetes, and “there aren’t situations like that involving the pancreas of a human being.”

Posted in: Health DOI: 10.1126/science.aan7190 Mitch Leslie

Mitch Leslie writes about cell biology and immunology.


Induction of IAPP amyloid deposition and associated diabetic abnormalities by a prion-like mechanism

 View ORCID ProfileAbhisek Mukherjee, Diego Morales-Scheihing, Natalia Salvadores, Ines Moreno-Gonzalez, Cesar Gonzalez, View ORCID ProfileKathleen Taylor-Presse, View ORCID ProfileNicolas Mendez, Mohammad Shahnawaz, View ORCID ProfileA. Osama Gaber, View ORCID ProfileOmaima M. Sabek, View ORCID ProfileDaniel W. Fraga, View ORCID ProfileClaudio Soto DOI: 10.1084/jem.20161134 | Published August 1, 2017

ArticleFigures & DataInfoMetrics Preview PDF Abstract

Although a large proportion of patients with type 2 diabetes (T2D) accumulate misfolded aggregates composed of the islet amyloid polypeptide (IAPP), its role in the disease is unknown. Here, we show that pancreatic IAPP aggregates can promote the misfolding and aggregation of endogenous IAPP in islet cultures obtained from transgenic mouse or healthy human pancreas. Islet homogenates immunodepleted with anti-IAPP–specific antibodies were not able to induce IAPP aggregation. Importantly, intraperitoneal inoculation of pancreatic homogenates containing IAPP aggregates into transgenic mice expressing human IAPP dramatically accelerates IAPP amyloid deposition, which was accompanied by clinical abnormalities typical of T2D, including hyperglycemia, impaired glucose tolerance, and a substantial reduction on β cell number and mass. Finally, induction of IAPP deposition and diabetic abnormalities were also induced in vivo by administration of IAPP aggregates prepared in vitro using pure, synthetic IAPP. Our findings suggest that some of the pathologic and clinical alterations of T2D might be transmissible through a similar mechanism by which prions propagate in prion diseases.

Submitted: 19 July 2016 Revision received 24 March 2017 Accepted: 19 June 2017 http://www.rupress.org/terms/https://creativecommons.org/licenses/by-nc-sa/4.0/ This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms/). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 International license, as described at https://creativecommons.org/licenses/by-nc-sa/4.0/).

View Full Text © 2017 Mukherjee et al.

i remember reading a lot about diabetes and tse prion during the BSE Inquiry days. i may have to go back and study that a bit closer.

also, interestingly, in the recent study with cwd and macaque, i also remember reading, In four animals wasting was observed, two of those had confirmed diabetes.

Alzheimer’s disease, iatrogenic, and Transmissible Spongiform Encephalopathy TSE Prion disease, that is the question ???
>>> The only tenable public line will be that "more research is required’’ <<<
>>> possibility on a transmissible prion remains open<<<
O.K., so it’s about 23 years later, so somebody please tell me, when is "more research is required’’ enough time for evaluation ?

[9. Whilst this matter is not at the moment directly concerned with the iatrogenic CJD cases from hgH, there remains a possibility of litigation here, and this presents an added complication. There are also results to be made available shortly (1) concerning a farmer with CJD who had BSE animals, (2) on the possible transmissibility of Alzheimer’s and (3) a CMO letter on prevention of iatrogenic CJD transmission in neurosurgery, all of which will serve to increase media interest.]

snip...see full Singeltary Nature comment here;
see Singeltary comments to Plos ;
BSE101/1 0136
From: . Dr J S Metiers 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) 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 further research to see 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.
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 in 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.
J S METTERS Room 509 Richmond House Pager No: 081-884 3344 Callsign: DOH 832 llllYc!eS 2 92/11.4/1.2
>>> The only tenable public line will be that "more research is required’’ <<<
>>> possibility on a transmissible prion remains open<<<
O.K., so it’s about 23 years later, so somebody please tell me, when is "more research is required’’ enough time for evaluation ?
 Re-Evidence for human transmission of amyloid-β pathology and cerebral amyloid angiopathy
Nature 525, 247?250 (10 September 2015) doi:10.1038/nature15369 Received 26 April 2015 Accepted 14 August 2015 Published online 09 September 2015 Updated online 11 September 2015 Erratum (October, 2015)
snip...see full Singeltary Nature comment here;
Self-Propagative Replication of Ab Oligomers Suggests Potential Transmissibility in Alzheimer Disease
*** Singeltary comment PLoS ***
Alzheimer’s disease and Transmissible Spongiform Encephalopathy prion disease, Iatrogenic, what if ?
Posted by flounder on 05 Nov 2014 at 21:27 GMT
Sunday, November 22, 2015
*** Effect of heating on the stability of amyloid A (AA) fibrils and the intra- and cross-species transmission of AA amyloidosis Abstract
Amyloid A (AA) amyloidosis is a protein misfolding disease characterized by extracellular deposition of AA fibrils. AA fibrils are found in several tissues from food animals with AA amyloidosis. For hygienic purposes, heating is widely used to inactivate microbes in food, but it is uncertain whether heating is sufficient to inactivate AA fibrils and prevent intra- or cross-species transmission. We examined the effect of heating (at 60 °C or 100 °C) and autoclaving (at 121 °C or 135 °C) on murine and bovine AA fibrils using Western blot analysis, transmission electron microscopy (TEM), and mouse model transmission experiments. TEM revealed that a mixture of AA fibrils and amorphous aggregates appeared after heating at 100 °C, whereas autoclaving at 135 °C produced large amorphous aggregates. AA fibrils retained antigen specificity in Western blot analysis when heated at 100 °C or autoclaved at 121 °C, but not when autoclaved at 135 °C. Transmissible pathogenicity of murine and bovine AA fibrils subjected to heating (at 60 °C or 100 °C) was significantly stimulated and resulted in amyloid deposition in mice. Autoclaving of murine AA fibrils at 121 °C or 135 °C significantly decreased amyloid deposition. Moreover, amyloid deposition in mice injected with murine AA fibrils was more severe than that in mice injected with bovine AA fibrils. Bovine AA fibrils autoclaved at 121 °C or 135 °C did not induce amyloid deposition in mice. These results suggest that AA fibrils are relatively heat stable and that similar to prions, autoclaving at 135 °C is required to destroy the pathogenicity of AA fibrils. These findings may contribute to the prevention of AA fibril transmission through food materials to different animals and especially to humans.
Purchase options Price * Issue Purchase USD 511.00 Article Purchase USD 54.00
*** Transmission of Creutzfeldt-Jakob disease to a chimpanzee by electrodes contaminated during neurosurgery ***
Gibbs CJ Jr, Asher DM, Kobrine A, Amyx HL, Sulima MP, Gajdusek DC. Laboratory of Central Nervous System Studies, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892.
Stereotactic multicontact electrodes used to probe the cerebral cortex of a middle aged woman with progressive dementia were previously implicated in the accidental transmission of Creutzfeldt-Jakob disease (CJD) to two younger patients. The diagnoses of CJD have been confirmed for all three cases. More than two years after their last use in humans, after three cleanings and repeated sterilisation in ethanol and formaldehyde vapour, the electrodes were implanted in the cortex of a chimpanzee. Eighteen months later the animal became ill with CJD. This finding serves to re-emphasise the potential danger posed by reuse of instruments contaminated with the agents of spongiform encephalopathies, even after scrupulous attempts to clean them.
Diagnosis and Reporting of Creutzfeldt-Jakob Disease
Singeltary, Sr et al. JAMA.2001; 285: 733-734. Vol. 285 No. 6, February 14, 2001 JAMA
Diagnosis and Reporting of Creutzfeldt-Jakob Disease
To the Editor: In their Research Letter, Dr Gibbons and colleagues1 reported that the annual US death rate due to Creutzfeldt-Jakob disease (CJD) has been stable since 1985. These estimates, however, are based only on reported cases, and do not include misdiagnosed or preclinical cases. It seems to me that misdiagnosis alone would drastically change these figures. An unknown number of persons with a diagnosis of Alzheimer disease in fact may have CJD, although only a small number of these patients receive the postmortem examination necessary to make this diagnosis. Furthermore, only a few states have made CJD reportable. Human and animal transmissible spongiform encephalopathies should be reportable nationwide and internationally.
Terry S. Singeltary, Sr Bacliff, Tex
1. Gibbons RV, Holman RC, Belay ED, Schonberger LB. Creutzfeldt-Jakob disease in the United States: 1979-1998. JAMA. 2000;284:2322-2323.

Terry S. Singeltary Sr.