key term - Prion disease

Definition

Prion disease refers to a group of progressive neurodegenerative disorders caused by misfolded proteins known as prions, which lead to brain damage and a variety of neurological symptoms. These diseases, such as Creutzfeldt-Jakob disease and mad cow disease, are characterized by the accumulation of abnormal protein aggregates that disrupt normal cellular functions and can be transmissible between individuals.

5 Must Know Facts For Your Next Test

1. Prion diseases are unique because they can be transmitted through contaminated food, surgical instruments, or even medical procedures, unlike most infectious diseases that are caused by bacteria or viruses.
2. The misfolded prion proteins induce neighboring normal proteins to also misfold, leading to a self-propagating cycle that causes extensive brain damage over time.
3. Symptoms of prion diseases may include cognitive decline, personality changes, impaired coordination, and ultimately severe neurological deficits.
4. There is currently no cure for prion diseases, and they are invariably fatal, often leading to death within months to a few years after symptoms begin.
5. Prion diseases are relatively rare but have significant public health implications due to their potential for transmission and their devastating effects on health.

Review Questions

• How do prions differ from other infectious agents like bacteria and viruses in terms of their structure and mechanism of action?
  • Prions differ fundamentally from bacteria and viruses because they are composed solely of protein, lacking any nucleic acids such as DNA or RNA. Their mechanism of action involves inducing normal proteins in the brain to misfold into the abnormal prion shape, leading to a cascade of misfolding that results in neurodegeneration. This unique property makes them particularly challenging to detect and eliminate compared to conventional pathogens.
• Discuss the role of prion proteins in the development of neurodegenerative diseases and how this impacts protein homeostasis in the brain.
  • Prion proteins play a critical role in the development of neurodegenerative diseases by destabilizing protein homeostasis within the brain. When prion proteins misfold, they disrupt the balance between protein synthesis and degradation, leading to an accumulation of toxic aggregates that compromise neuronal function. This imbalance triggers neuroinflammation and cell death, ultimately resulting in cognitive decline and motor dysfunction characteristic of prion diseases.
• Evaluate the implications of prion diseases on public health and safety, considering both transmissibility and the challenges associated with diagnosis and treatment.
  • The implications of prion diseases on public health are significant due to their transmissibility through contaminated materials and potential outbreaks, as seen with mad cow disease. The challenges associated with diagnosing prion diseases include their long incubation periods and the need for specialized tests, which can delay recognition and response. Additionally, the lack of effective treatments highlights the necessity for stringent safety measures in medical settings and food sources to prevent transmission and protect public health.

Related terms

Prion: An infectious agent composed entirely of protein that causes normal proteins in the brain to misfold and aggregate.

Neurodegeneration: The progressive loss of structure or function of neurons, leading to conditions such as prion diseases.

Amyloid: Abnormal protein aggregates that can form in various diseases, including prion diseases, leading to tissue damage.