Amyloid

File:Crossbeta.png

Crossbeta

Small bowel duodenum with amyloid deposition 20X

2rnm

Protofilament of Beta Amyloid

Three phases of amyloid fibril formation

Amyloid refers to a diverse group of protein aggregates that share common structural features and are associated with various diseases. These proteins misfold and form insoluble fibrils that deposit in tissues and organs, leading to a range of pathological conditions known as amyloidosis.

Structure and Formation

Amyloid fibrils are characterized by their beta-sheet-rich structure, which is detectable by techniques such as X-ray crystallography and electron microscopy. The process of amyloid formation typically involves the misfolding of normally soluble proteins or peptides into insoluble fibrils. These fibrils can then aggregate into larger deposits.

Types of Amyloid

There are several types of amyloid proteins, each associated with different diseases:

• Amyloid beta (Aβ): Associated with Alzheimer's disease.
• Transthyretin (TTR): Linked to familial amyloid polyneuropathy and senile systemic amyloidosis.
• Serum amyloid A (SAA): Involved in secondary amyloidosis.
• Islet amyloid polypeptide (IAPP): Found in type 2 diabetes.

Diseases Associated with Amyloid

Amyloid deposits can lead to a variety of diseases, collectively known as amyloidosis. These diseases can be systemic, affecting multiple organs, or localized, affecting specific tissues. Some of the major diseases include:

• Alzheimer's disease
• Parkinson's disease
• Huntington's disease
• Type 2 diabetes
• Familial amyloid polyneuropathy
• Senile systemic amyloidosis

Diagnosis and Treatment

The diagnosis of amyloidosis often involves a combination of clinical evaluation, imaging studies, and biopsy of affected tissues. Staining techniques, such as Congo red staining, are commonly used to identify amyloid deposits. Treatment strategies vary depending on the type of amyloid and the organs involved. They may include:

• Medications to reduce amyloid production or enhance its clearance.
• Supportive treatments to manage symptoms and organ dysfunction.
• In some cases, organ transplantation may be necessary.

Research and Future Directions

Ongoing research aims to better understand the mechanisms of amyloid formation and to develop more effective treatments. Advances in molecular biology, genetics, and pharmacology hold promise for new therapeutic approaches.

Related Pages

• Amyloidosis
• Alzheimer's disease
• Parkinson's disease
• Huntington's disease
• Type 2 diabetes
• Familial amyloid polyneuropathy
• Senile systemic amyloidosis
• Transthyretin
• Serum amyloid A
• Islet amyloid polypeptide

‎