Prions

Introduction

The prion protein and its misfold can lead to many diseases known as prion diseases. However, the reason behind the abnormal fold of these types of prions is still unknown. Every kind of disease that is caused by this, affects mainly the brains or the neural tissues. The main thing about prions is that they are .

What are Prions?

Figure 1: Human Prion Protein

The prion is a protein particle that is highly infectious and is responsible for many diseases that can cause brain damage. The term was first introduced in 1982 by Stanley B. Prusiner. The word prion is formed from with first and last part of protein and infection, respectively. It is a short form of the proteinaceous infectious particle.

They behave as an organism that can be contagious, but they do not have the fundamental features of an organism. For instance, they do not have RNA or DNA as the genetic material. It can cause many diseases such as CJD in mammals.

Prion’s Structure

Figure 2: Prion fold

Prion proteins can be found anywhere in the body, however, the ones that cause the disease have a different structure. There are two isoforms of prions that can be found and they are-

• PrPc - The main function of the PrPc still needs to be found out. However, they are found in the cell membrane and they play a significant role in the process of signalling and cell adhesion.

• PrPsc - This type of prions is the one that causes the disease. The most important thing about them is that they are proteases resistant. It can severely affect the PrPc prions and can change them.

The prions are believed to be more structured amyloid fibres. There are free proteins that are attached to the end of these fibres. Prions that have a similar type of amino acid can only bind but in some cases, cross binding is also possible.

Prion Infection

Those diseases that are caused by the prion protein abnormal fold are known as prion infection. They are transmissible and cause a very rare type of progressive neurodegenerative disorders. It can affect the brains of both animals and humans. They can even cause TSEs and act like an agent for this kind of disease. This kind of disease is usually counted as a deadly one.

Disease caused by Prions

Those prion diseases that can be caused by the abnormal fold of prion proteins are mainly neurodegenerative diseases. The prions are rare and cannot be transmitted easily. The diseases have a slow growth rate, which means they develop gradually.

The effect of this protein in every kind of animal is different. For example, in sheep it causes scrapie, in cows, it causes mad cow and chronicle diseases in deer. In humans, it causes CJD, fatal familial insomnia, kuru disease, etc.

Figure 3: Prion Protein that caused Mad Cow

Types of Disease

The diseases that are caused by the prion protein can be divided into three major types, they are-

• Acquired Prion Disease - One person gets exposed to the infectious protein. They can be transmitted by cannibalism.

• Genetic Prion Disease - It can affect a person by genetic transmissions, such as a mutation in some DNA.

• Sporadic Prion Disease - The cause of this disease is not confirmed. This is the most common type of prion disease.

Reason for Prion Disease

The main reasons that can cause the disease are-

• This disease can happen if there is a history of this disease in a family.

• Elderly people can get affected by this kind of disease.

• Consumption of too many animal-based products can lead to the transmission of the disease.

Symptoms and Treatment

The Symptoms of Prion disease

The most common symptoms of prion disease are -

• Depression

• Insomnia

• The loss of coordination

• Blindness or lack of vision

• Fatigue

• Hallucinations

• Dementia

Diagnosis and Treatment of Prion disease

It can be diagnosed by MRI or scan of the brain, tests that can analyze the brain waves, a fluid test of the spinal cord, or it can be detected by blood. The test that can show vision loss or nerve damage also helps to detect Prion diseases.

The treatment for this disease is still a matter of research because there is no proper treatment or medicines that can cure the Prion disease. Some medicines show slow effects and can slow down the growth of the disease.

Conclusion

The main reason of prior is believed as the cause is the abnormal folding of the prion proteins. They can break down nucleic acids. However, the most dangerous thing that is alarming about these proteins are that the diseases caused by these proteins are transmissible.

FAQs

Q1. Is prion disease curable?

Ans. The effect of this disease can slow down with proper medicine. It can slowdown the growth of prion proteins. The cure is still in the research stage because of the complexity of the human body.

Q2. What are the main effects of prion?

Ans. The main part of the brain gets affected by prion disease. The reason behind it is that the prion proteins are available only in the brain cells and in this disease the cells become abnormal and eventually lead to brain damage.

Q3. How to take prevention from prion disease?

Ans. The main way to prevent the disease caused by prion is to stay healthy and have a fresh mind. It is important to clean the medical equipment and sterilize them to stop the spreading of this disease.

Q4. Is Alzheimer's one kind of prion disease?

Ans. No, Alzheimer's is not a kind of disease that is caused by the prions. CJD or Creutzfeldt-Jakob disease is the most common form of prion disease in humans.