Key Information
Amyloidosis is a proteostatic disease , meaning a progressive disorder of extracellular deposition of insoluble protein fibrils in tissues.It affects , brain, kidney, nerves and almost any organ.Crucially, amyloid is an interstitial disease, accumulating strictly in the spaces between cells rather than inside them. This interstitial buildup exerts physical pressure, alters tissue architecture, and finally invading the cell and hence the organ function.
The primary culprit is a normal transport protein transthyretin (TTR) (same as prealbumin) It is synthesized in the liver as a stable, four-part tetramer structure that safely circulates in the blood. Under stressful or aging conditions, this tetramer destabilizes unstable monomer pieces. These monomers undergo misfolding, polymerizing into rigid cross-beta-sheet amyloid fibrils. These abnormal ATTR fibrils escape cellular degradation.