Prion Diseases: Harmful Or Infectious Protein

Creutzfeldt-Jakob Disease: It happens when a prion protein misfolds itself, thus causing a “domino effect” which unfolds itself causing a malfunction.

Proteinaceous Infectious Particles, commonly known as Prions, are extremely rare misfolds of the protein PrPc, which cause fatally neurodegenerative diseases, and are theorized to be infectious only by the protein itself (U.S National Library of Medicine, 1998). This “protein-only theory” is still heavily debated today, as some scientists deny the theory, and there isn’t a significant amount of evidence on each side to qualify the theory or disprove it (Soto, C. 2011). The base “Prion” protein is encoded in the gene PRNP, while being non-infectious. Prions are most commonly found in human prion diseases, but they can also be in other animals in the form of Mad Cow Disease and Chronic Wasting Disease, classified as Bovine Spongiform Encephalopathies

Humans have to deal with many different diseases and the ones most disliked are the ones with no cures. Like cancer, transmissible spongiform encephalopathies have no cure, but they are more rare. These diseases are prion diseases which cause the brain to deteriorate. Prions are proteins that sometimes behave like viruses, which mean that they should have some form of nucleic acid, but since they don’t, they cause abnormalities. The nervous system contains many normal prions, but when an abnormal prion comes along, it transforms all the normal prions into abnormal ones. Bovine spongiform encephalopathy is found in cattle, but it can be transmitted to humans.

     Mad Cow Disease, scientifically referred to as (BSE) Bovine Spongiform Encephalopathy, is a disease that affects those humans who eat the meat from infected cows. Mad Cow Disease is one of several fatal brain diseases called (TSE) Transmissible Spongiform Encephalopathy. (USDA) There was evidence of a new illness resembling the sheep disease scrapie. It was technically named BSE but quickly acquired the mad cow tag because of the way infected cattle behave. (CNN) In 1997, there was an award given to Stanley Prusiner, for concluding that a distorted protein called a prion was responsible for Mad Cow Disease, noted the long incubation period made it difficult to distinguish (Bryant).

In bovine spongiform encephalopathy (BSE), the disease is caused by the misfolding of proteins that cause proteins and peptides to develop a fibrillary structure. The PrPc is a correctly folded prion and the misfolded form is called PrPSc. BSE occurs when the normal PrPc come into contact with the toxic PrPSc and the normal prion takes on the shape of the PrPSc. The normal chaperones are unable to convert the PrPSc back to the normal form. The PrPSc now takes on the role of chaperone and the conversion of PrPc prions continue over and over. PrPSc, now being hydrophobic avoids the water of the inner cell and begin to accumulate and form plaques along the neuronal cell membranes. The aggregation of the prions on the cell membrane eventually lead to cell death which produces the sponge-like appearance in the brain of cattle infected with BSE (Thompson, 2014).

Encephalitis literally means an inflammation of the brain, but it usually refers to brain inflammation caused by a virus. It may also be called “acute viral encephalitis or aseptic encephalitis';. Encephalitis is an infectious disease of the Central Nervous System characterized by pathologic changes in both the gray and white matter of the spinal cord and brain. It may be due to specific disease entity such as rabies or an arthropod-borne virus (arbovirus), or it may occur as a sequela of influenza, measles, German measles, chicken pox, herpes virus infection, small pox, vaccinia, or other diseases. The specific viruses involved may vary. Exposure can also occur through insect bites, food or drink, or skin

Variant Creutzfeldt-Jakob disease (vCJD) is a rare and fatal human neurodegenerative condition falling under the category of Transmissible Spongiform Encephalopathy (TSE) because of having characteristic of spongy degeneration of the brain that it causes and its ability to be transmitted. First it was described in the United Kingdom in March 1996 and it has been connected with exposure to a TSE of cattle known as Bovine Spongiform Encephalopathy (BSE) sometimes called Classical BSE, having been reported first in 1986 in the United Kingdom.

The U.S. Department of Agriculture (USDA) has tested hundreds of thousands of cattle for BSE. Researchers believe that the infectious agent that causes mad cow disease is an abnormal version of a protein normally found on cell surfaces, called a prion. For reasons still unknown, this protein becomes altered and destroys nervous system tissue (brain and spinal cord). There exists strong epidemiologic and laboratory evidence for a causal association between a new human prion disease called variant Creutzfeldt-Jakob disease (vCJD) that was first reported from the United Kingdom in 1996 and the BSE outbreak in cattle (http://www.cdc.gov). According to The National Creutzfeldt-Jakob Disease Surveillance Unit, by June 2014 it had killed 177 people in the United Kingdom, and 52 elsewhere. This essay will focus on the possible causes, effects, and treatment for this

The aggregation of prion proteins and their transmissibility from one cell to another has been shown to be evident (Cushman et al.; Goedert et al. 2010), therefore strongly suggesting that these events may play a role in pathogenesis for many diseases, including both AD and PD. While none of these diseases is infectious in an identical way as

disease and Alzheimer’s. Severe infection that has spread to the brain, epilepsy, stroke, and the late

Chronic Wasting Disease (CWD) is a fatal neurodegenerative transmissible spongiform encephalopathy (TSE ) found in some white tailed deer. CWD is associated with diseases such as Mad-Cow disease, Scrapie, and Creutzfeldt–Jakob disease. With well supported evidence it is hypothesized that CWD originated from Scrapie. The causation of CWD is an abnormal form of PrPcwd prion. This prion is a naturally occurring protein found in mammals. Prions lack genome and are highly resistant to degradation. Chronic Wasting Disease can be transmitted by direct contact between the animals and/or on resources such as salt licks.

The causes of Alzheimer’s are not yet fully understood; however, its effect on the brain can be understood. Alzheimer’s disease - insidious, attacking and terrifying - stalks and then murders brain cells. A brain afflicted with Alzheimer’s disease has a decreased count in cells and connections among cells. The more brain cells die, the smaller the brain of a person with Alzheimer’s gets. When doctors examine a brain with Alzheimer’s tissue, they see two types of deformities that are known to be trademarks of the disease. The first trademark is known as plaque, which is a cluster of a beta-amyloid protein that may damage and kill brain cells in a number of ways, including blocking with cell-to-cell communication. Whereas the final cause of brain-cell death in Alzheimer’s remains a mystery, the groups of beta-amyloids that cover the brain cells are a sure sign of the disease. The second trademark of Alzheimer’s is the tangle. Brain cells are reliant on internal support and a transport system to bring nutrients and other essentials to their distant regions. This system needs a protein called tau. In Alzheimer’s, strings of tau protein roll into abnormal tangles inside brain cells, concluding in failure of the cell's transport system. This breakdown of the system is powerfully involved in the decline and death of brain

Shrinkage in parts of the brain such as the cortex and hippocampus, affects functions such as remembering, planning and even thinking. The remaining tissue contains plaque, abnormal clusters of protein fragments, between surviving nerve cells. This plague can block cell-to-cell signaling at synapses and activate immune system cells that trigger inflammation while devouring disabled cells. The dead and dying nerve cells contains tangles, which are made up of twisted strands of another protein. Tangles destroy a vital cell transport made of proteins, which block nutrients and other essential supplies from reaching cells, which then die. The progression of Alzheimer’s disease follows the spreading of plaque and tangles throughout the brain. The escalation damage areas of the brain that involve speaking and understanding speech and also the sense of where a body is in relation to surrounding objects. In severe cases of Alzheimer’s, where the cortex is intensively damaged, the brain shrinks so dramatically due to widespread cell death that individuals lose the ability to communicate, recognize loved ones, and care for

Like in Alzheimer’s disease we found under the microscope that normally soluble proteins misfolded into a beta pleated pattern and change into insoluble fibrillary amyloid ,and there are also many causes of dementia like Vascular dementia where the cause is stroke or decrease in the blood supply to one of the areas of the brain . Lew body dementia is due to lew body deposits which abnormal clumps of protein deposit inside the brain , and Frontotemporal dementia is a degeneration of nerve cells in frontal and temporal lobe of the brain leads to personality

Prions are a type of protein found naturally in the brain and other regions of the central nervous system. The diseases associated with