Prion Diseases Essay

2410 words - 10 pages

Prion Diseases

Transmissible spongiform encephalopathies (TSEs) are neurodegenerative diseases that are thought to be caused by the misfolding of prion proteins. Prions are able to replicate in the absence of nucleic acids. TSEs include: scrapie, bovine spongiform encephalopathy, Creutzfeldt-Jakob disease, kuru, Gerstmann-Straussler-Scheinker disease, and Fatal Familial Insomnia. They can affect many different animals, including humans. Currently, there are no ways to diagnose, treat, or cure TSEs, as much more research is needed before these diseases are completely understood.
1. Overview
Prions are a type of protein found naturally in the brain and other regions of the central nervous system. The diseases associated with prions are collectively known as transmissible spongiform encephalopathies (TSEs). “Transmissible” refers to their potentially infectious nature, and “spongiform encephalopathies” indicates the microscopic sponge-like deterioration of the brain caused by the progression of the disorders. While these fatal neurodegenerative diseases exhibit different clinical symptoms, have different incubation periods, and even target different areas of the brain, they do share a number of characteristics. They occur in both animals and humans. During a silent incubation period, there are no detectable signs of the disease, although depending on the specific disease, the length of the incubation period can “vary from a few weeks to up to 40 [years]” (Baker & Ridley, 1996, 1). Due to their unique method of propagation (which will be addressed later), TSEs present a seeming paradox in that “inherited cases give rise to a disease that is transmissible but acquired cases do not produce heritable diseases” (Baker & Ridley, 1996, 1). Most important, these disorders are grouped together because they share one significant molecular element: the misfolded prion protein.
2. The Prion Protein and Its Function
The prion protein (PrP) is unusual in that it has two stable isoforms. The cellular or normal form of the prion protein is termed PrPC, while the disease form is termed PrPSC. Sharing the same sequence of amino acids, or primary structure, PrPC and PrPSC differ in their secondary, tertiary, and quaternary structures. The normal prion protein has N- and C-terminals, three alpha helices, and two beta sheets (Soto, 2006, 40). Its function is still not completely understood. However, scientists have found evidence that point to various possibilities. 1) Because most PrPC are located in lipid rafts, membrane structures involved in signaling, it is suggested that PrPC may also be a mediator in neuroprotective signaling pathways. 2) Interaction between PrPC and Bcl-2, a ligand involved in protecting neurons from apoptosis, suggests the possibility that PrPC may be an antiapoptotic protein. 3) PrPC has also been linked to copper metabolism in the brain. In one particular study, PrP knockout mice, or mice that were genetically altered to...

Find Another Essay On Prion Diseases

Prions the Proteinacious Killer Essay

1032 words - 4 pages , including humans. The actual means by which PrPSc propagates itself remains unknown but scientists believe the modified protein alters the normal protein molecules. The diseases may be contracted in a variety of ways. They may be genetically inherited, acquired by contamination, or occur sporadically on their own. All forms, however, are fatal. The Prion Diseases: Several diseases can result from prions. Such diseases are known as spongiform

Protein Folding Essay

3270 words - 14 pages Background: Prions are a particular type of amyloids that are related to a great variety of important processes in cells, but also responsible for serious diseases in mammals and human. Prion-related aggregation is mediated by specific protein domains with remarkable compositional bias towards glutamine/asparagine and against charged residues and prolines. The number of prions experimentally characterized nowadays corresponds to a handful of

Bacteria, Viruses and Prions

1604 words - 7 pages , jaundice, bleeding, and/or shock of organs. Prions refer to abnormal and pathogenic agents that get transferred. Normal prion proteins are found within the body and the brain and lack nucleic acids. They help neurons communicate and help transport minerals. The amino acids within prions fold up into a helical shape. In prion diseases, prions fold into an unusual shape to allow the flat structure to replace the helical shape. The unusual prion diseases


1711 words - 7 pages . Eventhough other prion diseases such as Kuru are transmitted by brain ingestion, Kuru is a disease unique for humans while BSE is related only, until now, to other animals. Other prion diseases related to other animals are Scrapie, which attacks sheep, Transmissible Mink Encephalopaty, which attacks mink and Chronic Wasting Disease which attacks elks and muledeers.It is known that BSE was adquired by British cows when they started consuming a

Creutzfeldt-Jakob disease

1070 words - 4 pages . Creutzfeldt-Jakob disease is rare, but the most common of the human prion protein diseases. This disease occurs at a worldwide rate of about one case per one-millionth person. For about 85% of these cases, the duration of the disease is about four months after the onset of symptoms. Since 2006 researchers have been performing test to see if donors with Creutzfeldt-Jakob disease were capable of passing the disease to patients through blood transfusion

Speech on different pathogens and the diseases they cause.

611 words - 2 pages Hello Everyone. I'm here to talk about the difference between prions, viruses, bacteria, protozoans, fungi and macro-parasites. These are all pathogens that cause diseases. I will also be giving examples of the diseases that these pathogens cause.Prions are infectious agents which do not have a nucleic acid genome. Prion diseases are often called spongiform encephalopathies (mad cows disease) because of the post mortem appearance of the brain

Cummings paper

2271 words - 9 pages ground meat and bone meal byproducts from sheep) changed the way they processed feed. The change somehow allowed the scrapie disease agent to survive the cattle feed production process, leading to the silent spread of the mad cow disease epidemic.The best known of the human prion diseases is Creutzfeldt-Jakob disease (CJD). This is a rapidly progressive, fatal, neurodegenerative disorder. The onset of symptoms of this disease usually occurs at

Creutzfeldt-Jakob Disease (CJD)

2695 words - 11 pages Creutzfeldt-Jakob disease (CJD)—a fatal neurodegenerative illness, is one form of transmissible spongiform encephalopathies (TSE) affecting humans. The suspected causal agent of these diseases is the prion—a proteinaceous infectious particle. Designated as PrPSC, this infectious protein is unique in that it does not contain nucleic acid, which is different from a virus, yet has the capability of replication and being transmitted to other hosts

Neurodegenerative Diseases

2019 words - 8 pages , astrocytosis and amyloid plaque formation. (1) Prion diseases are also referred to as spongiform encephalopathies because of the evident numerous holes found in the spongy brain tissue. (1,2,4) When spongiform change is present in human brain tissue a numerous small holes are present in histological samples of the affected tissue. The frequency and morphology of these holes are not a normal feature of brain tissue, but a feature of CJD affected

The Media and Mad Cow Disease

766 words - 3 pages junior at Cornell when he wrote it and is now a medical student at Tufts University School of Medicine.But according to Dr. Scott Ratzan, the director of health communications at Emerson College, the hypothesis that CJD is linked to Mad Cow disease turned out to be false. "We still don't know how humans contract CJD, but what is clear is that people do not get it by eating meat from cows or lamb. The mad cow prion has only been found in the

Mad Cow Disease

1845 words - 7 pages Mad Cow Disease Bovine spongiform encephalopathy (BSE), better know as Mad cow disease is a relatively new disease. Most sources state that BSE first showed up in Great Britain in 1986 [Dealler p.5] but some say it popped up in 1985 [Greger p.1]. However the official notification was not until 21 June, 1988 [Dealler stats. p.1]. Spongiform encephalopathies are invariable fatal neurodegenerative diseases and there is no treatment nor is there

Similar Essays

Investigating Prion Diseases Essay

1938 words - 8 pages that revolve around them, because exactly how they are transmitted remains unknown. The primary theory is that all TSEs are prion caused diseases, but unanswered questions about the precise methods that prions use have encouraged scientists to form a new theory: BSE, sCJD, and possibly nvCJD are all autoimmune disease caused by the Acinetobacter bacteria. The controversial argument along with the basic symptoms of BSE, sCJD, and nvCJD are

How To Treat Prion Diseases Essay

1607 words - 6 pages How to Treat Prion Diseases Abstract Scientists are stumped as to the development and nature of proteinaceous infectious particles. Neither virus nor bacteria, these prions, are believed to cause transmissible spongiform encephalopathies (TSE), rare diseases said to be 100% fatal, without possessing nucleic acids. Their unhindered growth is thought to be the cause for bovine spongiform encephalopathy (BSE), or Mad Cow Disease, Creutzfeldt

The Underlying Genetic Cause Of Prion Diseases

2740 words - 11 pages The human genome contains millions of base pairs that are successfully transcribed and translated to yield the gene products necessary for life. On occasion the protein products of translation face mutations that make them lethal to the human condition. In the past decade prion diseases have become more prominent in civilian life like mad cow disease in cattle, kuru in humans, and scrapie in sheep (Araújo, 2013). Prions are proteins that

True Nature Of Prions Essay

1330 words - 5 pages of prion material. The diseases that these prions cause have recently been a major cause for concern and scientists worldwide are frantic for answers. Perhaps further experimentation should be done concerning the excision of the normal Prp genes. If they are indeed unnecessary for survival, perhaps these genes could be removed from bovine DNA as well. These cows could then be cloned, and remain symptom free. But would the consumers of the beef