Clearance of extracellular misfolded proteins in systemic amyloidosis: experience with transthyretin.

Increasing evidence indicates that accumulation of misfolded proteins in the form of oligomers, protofibrils or amyloid fibrils, and their consequences in triggering intracellular signaling cascades with toxic consequences represent unifying events in many of slowly progressive neurodegenerative disorders. Studies with small compounds or molecules, known to recognize and disrupt amyloidogenic structures, have proven efficient in promoting clearance of protein aggregates in experimental models of systemic and localized forms of amyloidoses. Doxycycline and EGCG were efficient in removing aggregates in pre-clinical studies in a transgenic mouse model for transthyretin (TTR) systemic amyloidosis and represent an opportunity to address mechanisms and key players in deposit removal. Extracellular chaperones, such as clusterin and metalloproteinases play an important role in this process.