These results suggest that
scrapie prions may have the potential to infect humans and raise new questions about the possible link between animal and human prions.
The transmission of different
scrapie prions in these mice also led to the propagation of prions that appear identical to those causing sCJD in humans.
They found that the transgenic mice were susceptible to classical and atypical Bovine Spongiform Encephalopathy prions, and also to mouse - derived
Scrapie prions.
«
Scrapie prions may even protect humans [from BSE].»
The heat rendering process, they suggest, may in fact destroy or otherwise inactivate
the scrapie prions, paving the way for the scarcer but more hardy BSE prions to infect the cattle.
The idea is that
scrapie prions might somehow interfere with the infectivity of BSE prions.
You wipe out the labile
scrapie prion» by heat rendering, Prusiner says.
The duo admits they have little evidence to back up their proposal, but they point to studies in their lab on mice, which were altered to be susceptible to both BSE and
scrapie prion infection.
In their study, the NIAID scientists injected infectious
scrapie prion protein into the brains of mice.
Not exact matches
By this time it was known that BSE was a
prion disease but whether the infective
prion came from
scrapie - infected sheep or another source is still not known.
While the diseases have similar symptoms, BSE
prions do not trigger
scrapie and vice versa.
Prion specialist Moira Bruce of the Institute for Animal Health's Neuropathogenesis Unit in Edinburgh says that sheep experimentally infected with BSE become ill about as fast as sheep naturally infected with
scrapie.
With the scale of the nvCJD threat to public health still unclear, scientists have been busy investigating the relationship between the strains of
prions blamed for neurodegenerative illnesses, including the presumed connection between BSE and
scrapie.
Degenerative brain diseases like mad cow disease (officially known as bovine spongiform encephalopathy, or BSE),
scrapie in sheep, and vCJD in humans are thought to be caused by
prions, misfolded versions of a normal cellular protein called PrPC.
She wonders if the animals actually contracted
scrapie, another
prion disease, because of lab contamination.
They found that although the protein stayed soluble for a week or two, it eventually polymerized into long fibers resembling those in so - called
prion diseases — brain diseases such as
scrapie in sheep, «mad cow disease» in cattle, and Creutzfeldt - Jakob disease in humans.
Other
prion diseases include
scrapie in sheep; chronic wasting disease in deer, elk and moose; and bovine spongiform encephalopathy (BSE), or mad cow disease, in cattle.
The researchers then exposed these transgenic mice to
prion isolates collected from sick animals, including classical and atypical strains of Bovine Spongiform Encephalopathy (i.e., mad cow disease), sheep
Scrapie, and deer Chronic Wasting Disease.
Other
prion diseases include
scrapie in sheep, chronic wasting disease in deer, elk and moose, and bovine spongiform encephalopathy in cattle.
Infamous for causing fatal degenerative brain diseases, such as bovine spongiform encephalopathy, known more commonly as «mad cow disease,» Creutzfeldt - Jakob disease, and
scrapie,
prions are proteins that have the ability to self - perpetuate when they assume a particular conformation.
Scientists have located two possible receptors for the so - called
prion protein (PrP) believed to be at fault in fatal neurological conditions such as «mad cow disease,» Creutzfeldt - Jakob disease in humans, and
scrapie in sheep.
It cause animal brains to turn into a spongy mess in
scrapie, a disease of sheep, and in bovine spongiform encephalopathy (BSE or «mad cow disease»), as well as in human
prion diseases such as CJD.
Scientists now believe that the brain - wasting disease
scrapie is caused by
prions, warped proteins that trick normal proteins into
Scientists now know that
scrapie is caused by misfolding proteins in the brain called
prions, the same mechanism that causes Creutzfeldt - Jakob disease in humans.
To test their findings, the researchers inoculated transgenic mice with
prions from sheep with
scrapie, another
prion disease causing neurological damage, and determined that these
prions have dramatically different biological properties.
While the origins of BSE remain obscure, one possibility is that the cattle developed the disease by being fed meat and bone meal contaminated with
prions from the sheep with the disease,
scrapie.
Prions are responsible for «mad cow» disease in cattle,
scrapie in sheep, and Creutzfeld - Jakob and other fatal ailments in humans.
The new finding offers direct, physical evidence supporting protein - based inheritance, thus strengthening the «
prion hypothesis» of the cause of neurodegenerative diseases in mammals, such as sheep
scrapie, mad cow disease (or bovine spongiform encephalopathy) and the kuru disease of the Papua New Guinea tribes.