Early detection of inflammation-associated amyloid in murine spleen using thioflavin T fluorescence of spleen homogenates: Implications for amyloidogenesis

Abstract

Amyloid is a generic term which refers to extracellular protein deposits with specific staining, morphological, and structural properties, that are seen in a variety of clinical disorders, the most common of which is Alzheimer's disease. In rapid induction models of murine inflammation-associated (AA) amyloid, amyloid deposits cannot be detected in the spleen by conventional histochemical techniques earlier than 36–48 h after administration of the amyloidogenic stimulus. The fluorescent dye Thioflavin T exhibits specific excitation emission wavelength shifts when bound by amyloid. In the present studies, an existing Thioflavin T fluorescence assay was modified and evaluated for its ability to detect amyloid fonnation during accelerated murine splenic AA amyloidogenesis. Concentrations of fibrils as low as 50 m;g/ml were measurable. Furthermore, the assay reliably identified amyloid in splenic homogenates 18 h following the amyloidogenic stimulus, a time point 18–24 h prior to the initial histological dete...