The fluorescent Congo red derivative, (trans, trans)-1-bromo-2,5-bis-(3-hydroxycarbonyl-4-hydroxy)styrylbenzene (BSB), labels diverse beta-pleated sheet structures in postmortem human neurodegenerative disease brains

A novel Congo red-derived fluorescent probe (trans, trans),-1-bromo-2,5-bis-(3-hydroxycarbonyl-4-hydroxy)styrylbenzene (BSB) that binds to amyloid plaques of postmortem Alzheimer's disease brains and in transgenic mouse brains in vivo was designed as a prototype imaging agent for Alzheimer's disease. In the current study, we used BSB to probe postmortem tissues from patients with various neurodegenerative diseases with diagnostic lesions characterized by fibrillar intra- or extracellular lesions and compared these results with standard histochemical dyes such as thioflavin S and immunohistochemical stains specific for the same lesions. These data show that BSB binds not only to extracellular amyloid beta protein, but also many intracellular lesions composed of abnormal tau and synuclein proteins and suggests that radioiodinated BSB derivatives or related ligands may be useful imaging agents to monitor diverse amyloids in vivo.