PhD Scientific Days 2019

Budapest, April 25–26, 2019

PharmacoSTORM: a powerful approach for antibody- or fluorescent protein-free super-resolution imaging

Prokop, Susanne

Prokop Susanne1,2, Ábrányi-Balogh Péter3, Barna László1, Urbán Gabriella1, Dudok Barna5, Vámosi Márton1, Attila Egyed3, Hui Deng4, Mario van der Stelt4, Keserű M. György3, Katona István1

1) Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Hungarian Academy
of Sciences, Budapest, Hungary
2) János Szentágothai Doctoral School of Neurosciences, Semmelweis University, Budapest, Hungary
3) Medicinal Chemistry Research Group, Research Centre for Natural Sciences, Hungarian Academy of
Sciences, Budapest, Hungary
4) Fundamental Research in Chemical Biology, Leiden Institute of Chemistry, Leiden, Netherlands
5) Stanford School of Medicine, Department of Neurosurgery, California, USA

Language of the presentation

English

Text of the abstract

A major challenge for contemporary neuroscience is to uncover the nanoscale molecular changes underlying neuropsychiatric diseases. Super-resolution imaging techniques, such as Stochastic Optical Reconstruction Microscopy (STORM) or Photo-Activated Localization Microscopy (PALM) are the methods of choice for visualization of nanoscale protein distribution, but these approaches suffer from the lack of selective antibodies against important molecular targets. Here we introduce PharmacoSTORM, which uses specific ligands labeled with proper fluorescent dyes to measure the nanoscale distribution of signaling molecules. We first compared immuno- and ligand stainings using antibodies and Alexa647-labeled ligands targeting the α7-nicotinic acetylcholine receptor. Notably, the signals acquired by different labeling procedures showed high degree of correlation. In agreement with the basic pharmacological principles, the signal intensities originating from fluorescent ligand binding were saturable. The superior sensitivity of super-resolution imaging was reflected by the fact that low concentration of the fluorescent ligand was not visible with confocal microscopy, but was detectable with STORM imaging. Since ligand-based staining lacks amplification steps, this approach can more precisely determine molecular quantity. Finally, to demonstrate the universal applicability of the PharmacoSTORM approach, we have also developed novel compounds, which enabled the nanoscale visualization of the CB1 cannabinoid and the D3 dopamine receptors, two G protein-coupled receptors widely implicated in many neuropsychiatric disorders. PharmacoSTORM by these compounds allowed the qualitative and quantitative pharmacological profiling of nanoscale receptor distribution. In summary, we propose that PharmacoSTORM is an efficient new tool for super-resolution imaging of difficult and low-copy number molecular targets.

Data of the presenter

János Szentágothai Doctoral School of Neurosciences, Semmelweis University, Budapest, Hungary
Supervisor: István Katona
prokop.susanne@koki.mta.hu