OO008 - A NOVEL PROXIMITY LIGATION ASSAY TARGETING PHOSPHORYLATED ALPHA-SYNUCLEIN AND TAU REVEALS PREVIOUSLY UNDETECTED PATHOLOGY ON POST MORTEM BRAIN TISSUE. (ID 1055)
Abstract
Aims
Neurodegenerative diseases (NDDs) including Alzheimer’s disease (AD), Parkinson’s disease (PD), and dementia with Lewy bodies (DLB) display various forms of phosphorylated tau and/or alpha-synuclein (α-syn) aggregates in neuronal or glial cells. However, the conformational and morphological properties of such aggregates have been incompletely characterized. Aim of this study is to investigate the patho-morphological properties of phosphorylated tau and α-syn aggregates with sensitive proximity ligation assay (PLA) technique.
Methods
Here, we have exploited the sensitivity and <40 nm resolution of proximity ligation assay, along with the selectivity of antibodies directed against phosphorylated tau and α-syn.
Results
Our results indicate that PLA, with antibodies recognizing phosphorylated tau or α-syn epitopes, revealed earlier pathology compared to conventional immunohistochemistry (IHC) on post mortem brain tissue from NDD patients. Apart from displaying classic lesions and dystrophic neurites, punctate neuropil signal, patchy and clustered intra-perikaryal constellations of diffuse cytoplasmic aggregates were detected. Furthermore, we observed unique patho-morphological staining patterns of intercellular protrusions / apical dendrites in adjacent cells that could not be visualized by conventional IHC using the same antibodies.
Conclusions
Our novel PLA with a dual phosphorylated antibody approach, can successfully detect earlier pathology on post mortem brain tissues from patients with NDDs.
