Spatially-resolved metabolic profiling of living Drosophila in neurodegenerative conditions using 1H magic angle spinning NMR

Maxime Yon,Vincent Sarou-Kanian,Serge Birman,Franck Fayon,Martine Decoville

doi:10.1038/s41598-020-66218-z

Abstract

Drosophila flies are versatile animal models for the study of gene mutations in neuronal pathologies. Their small size allows performing in vivo Magic Angle Spinning (MAS) experiments to obtain high-resolution 1H nuclear magnetic resonance (NMR) spectra. Here, we use spatially-resolved 1H high-resolution MAS NMR to investigate in vivo metabolite contents in different segments of the fly body. A comparative study of metabolic changes was performed for three neurodegenerative disorders: two cell-specific neuronal and glial models of Huntington disease (HD) and a model of glutamate excitotoxicity. It is shown that these pathologies are characterized by specific and sometimes anatomically localized variations in metabolite concentrations. In two cases, the modifications of 1H MAS NMR spectra localized in fly heads were significant enough to allow the creation of a predictive model.

Highlights

Drosophila flies are versatile animal models for the study of gene mutations in neuronal pathologies
For 10-day-old flies that are at a pre-symptomatic stage[26], no obvious differences were detected between the control and neuronal HD model (NHD) model spectra, except in the thorax where the phosphocholine signal (3.21 ppm) was found to be increased in the diseased flies
A strong increase in phosphocholine content was found selectively in the abdomen of the glutamate excitotoxicity (GLU) flies. In agreement with these 1H nuclear magnetic resonance (NMR) results, a biochemical dosage of trehalose performed on the whole fly indicated a significant increase in trehalose level in the GLU model compared to controls

Summary

Introduction

Drosophila flies are versatile animal models for the study of gene mutations in neuronal pathologies. Their small size allows performing in vivo Magic Angle Spinning (MAS) experiments to obtain highresolution 1H nuclear magnetic resonance (NMR) spectra. A comparative study of metabolic changes was performed for three neurodegenerative disorders: two cell-specific neuronal and glial models of Huntington disease (HD) and a model of glutamate excitotoxicity. It is shown that relative quantification of four main metabolites (fatty acids, glycerol, phosphocholine, and trehalose) by in vivo localized 1H HRMAS NMR spectroscopy enables to evidence significant metabolic differences between diseased and control flies in each part of the Drosophila body (head, thorax and abdomen). For the GLU and GHD models, we show that the relative changes of metabolite levels in fly heads allow discriminating diseased and control flies by partial least squares-discriminant analysis (PLS-DA)

Methods

Results

Discussion

Conclusion