Amyloid Protein SAA, also known as Serum Amyloid A, is a type of protein produced by the liver and secreted into the bloodstream. It is part of the acute-phase response, which is the body's defense mechanism against infections, inflammation, and tissue injury. SAA is synthesized in response to various inflammatory mediators, such as cytokines, and its levels increase dramatically during inflammation.
The primary function of SAA is to bind to high-density lipoproteins (HDL) in order to regulate lipid metabolism and transport. SAA also plays a crucial role in tissue remodeling and repair, as it can promote the recruitment of immune cells to the site of injury and facilitate wound healing. In addition, SAA possesses antimicrobial properties, protecting the body against certain pathogens.
However, under certain circumstances, long-term elevation of SAA levels can lead to the formation of amyloid fibrils - abnormal aggregations of proteins - in various tissues and organs throughout the body. These amyloid deposits can disrupt normal tissue structure and function, resulting in the development of amyloidosis, a group of disorders characterized by the accumulation of amyloid proteins.
In summary, Amyloid Protein SAA is an acute-phase protein that helps regulate lipid metabolism, modulate the inflammatory response, promote tissue repair, and protect against pathogens. However, excessive and prolonged elevation of SAA levels can lead to the formation of amyloid deposits and subsequent tissue damage, as seen in amyloidosis.
