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

Abstract

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.

Figure 1.

Schematic illustration of BSB.

Figure 2.

Neurodegenerative lesions composed of Aβ protein. This figure depicts tissue sections of frontal cortex immunostained with MAB. BCO5, first column; BA27, second column; 4G8, third column, or stained with BSB, fourth column; and THIOS, fifth column. The first row (A–E) shows an AD case, the second row (F–J) shows a DS case with AD, and the third row (K–M) shows a case of FAD with a mutation in PS2. The asterisks indicate the blood vessel that was used as landmark to identify the same area in each set of consecutive sections. The arrows point to the same subpial Aβ deposit. All images were taken at the same magnification. Scale bar, 100 μm.

Figure 3.

Neurodegenerative lesions composed of tau protein. This figure shows tau immunoreactive lesions in various neurodegenerative diseases stained with BSB and THIOS. All sections in the first row (A–F) were stained with BSB and all sections in the second row (G–L) were stained with THIOS. In the third row the sections depicted in panels M and N are stained with BSB and in panels O to Q are immunostained with antiserum 17026. A and G: NFTs and Aβ plaques from an AD patient. B and H: Coiled bodies in the midbrain of a patient with PSP. C and I: Globose tangles in the midbrain of a patient with PSP. D and J: Pick bodies in the dentate gyrus of a patient with Pick’s disease. E, K, and P: Consecutive sections through the pons of a FTDP-17 (N279K) patient. P shows tau-positive neurons and neuropil threads. Both BSB and THIOS stain some neuropil threads in adjacent sections (E and K, respectively) but tau immunopositive neurons are not stained. Asterisks indicate the same blood vessel in these images and the arrows point to NTs. F, L, and Q: Coiled bodies in a patient with familial PSG (exon 10 + 16 mutation). M: NT pathology in a CBD patient. N and O: Tau and BSB stained glia (arrows) in the amygdala of a FTDP-17 (P301L) patient. A, C, G, I, and M are the same magnification; scale bar in A = 20 μm. B, H, L, and Q are the same magnification; scale bar in L = 10 μm. D, F, J, N, and O are the same magnification; scale bar in N = 10 μm. E, K, and P are the same magnification; scale bar in P = 50 μm.

Figure 4.

Neurodegenerative lesions composed of α-synuclein. The first column of this figure depicts tissue sections immunostained with Syn303. The second and third columns show tissue sections stained with BSB and THIOS, respectively. A to C: Cerebellar white matter flanked on the top and the bottom by granule cell layers of a patient with MSA. Arrows point to CGIs in each of the three panels. D: Several cortical LBs in the cingulate cortex of a patient with DLB/PD. In contrast to the α-synuclein antibody, BSB (E) and THIOS (F) stain only a few LBs in adjacent tissue sections. Arrows point to LBs in all three panels. G: A large number of α-synuclein-positive inclusions in the CA3 region of the hippocampus of a patient with NBIA-1. H and I were taken from adjacent tissue sections and show rare globules but no perikaryal inclusions. All panels are the same magnification; scale bar in A = 20 μm.