Cargando…

Triose-phosphate isomerase deficiency is associated with a dysregulation of synaptic vesicle recycling in Drosophila melanogaster

INTRODUCTION: Numerous neurodegenerative diseases are associated with neuronal dysfunction caused by increased redox stress, often linked to aberrant production of redox-active molecules such as nitric oxide (NO) or oxygen free radicals. One such protein affected by redox-mediated changes is the gly...

Descripción completa

Detalles Bibliográficos
Autores principales: Stone, Aelfwin, Cujic, Oliver, Rowlett, Angel, Aderhold, Sophia, Savage, Emma, Graham, Bruce, Steinert, Joern R.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10011161/
https://www.ncbi.nlm.nih.gov/pubmed/36926383
http://dx.doi.org/10.3389/fnsyn.2023.1124061
_version_ 1784906328144084992
author Stone, Aelfwin
Cujic, Oliver
Rowlett, Angel
Aderhold, Sophia
Savage, Emma
Graham, Bruce
Steinert, Joern R.
author_facet Stone, Aelfwin
Cujic, Oliver
Rowlett, Angel
Aderhold, Sophia
Savage, Emma
Graham, Bruce
Steinert, Joern R.
author_sort Stone, Aelfwin
collection PubMed
description INTRODUCTION: Numerous neurodegenerative diseases are associated with neuronal dysfunction caused by increased redox stress, often linked to aberrant production of redox-active molecules such as nitric oxide (NO) or oxygen free radicals. One such protein affected by redox-mediated changes is the glycolytic enzyme triose-phosphate isomerase (TPI), which has been shown to undergo 3-nitrotyrosination (a NO-mediated post-translational modification) rendering it inactive. The resulting neuronal changes caused by this modification are not well understood. However, associated glycation-induced cytotoxicity has been reported, thus potentially causing neuronal and synaptic dysfunction via compromising synaptic vesicle recycling. METHODS: This work uses Drosophila melanogaster to identify the impacts of altered TPI activity on neuronal physiology, linking aberrant TPI function and redox stress to neuronal defects. We used Drosophila mutants expressing a missense allele of the TPI protein, M81T, identified in a previous screen and resulting in an inactive mutant of the TPI protein (TPI(M81T), wstd(1)). We assessed synaptic physiology at the glutamatergic Drosophila neuromuscular junction (NMJ), synapse morphology and behavioural phenotypes, as well as impacts on longevity. RESULTS: Electrophysiological recordings of evoked and spontaneous excitatory junctional currents, alongside high frequency train stimulations and recovery protocols, were applied to investigate synaptic depletion and subsequent recovery. Single synaptic currents were unaltered in the presence of the wstd(1) mutation, but frequencies of spontaneous events were reduced. Wstd(1) larvae also showed enhanced vesicle depletion rates at higher frequency stimulation, and subsequent recovery times for evoked synaptic responses were prolonged. A computational model showed that TPI mutant larvae exhibited a significant decline in activity-dependent vesicle recycling, which manifests itself as increased recovery times for the readily-releasable vesicle pool. Confocal images of NMJs showed no morphological or developmental differences between wild-type and wstd(1) but TPI mutants exhibited learning impairments as assessed by olfactory associative learning assays. DISCUSSION: Our data suggests that the wstd(1) phenotype is partially due to altered vesicle dynamics, involving a reduced vesicle pool replenishment, and altered endo/exocytosis processes. This may result in learning and memory impairments and neuronal dysfunction potentially also presenting a contributing factor to other reported neuronal phenotypes.
format Online
Article
Text
id pubmed-10011161
institution National Center for Biotechnology Information
language English
publishDate 2023
publisher Frontiers Media S.A.
record_format MEDLINE/PubMed
spelling pubmed-100111612023-03-15 Triose-phosphate isomerase deficiency is associated with a dysregulation of synaptic vesicle recycling in Drosophila melanogaster Stone, Aelfwin Cujic, Oliver Rowlett, Angel Aderhold, Sophia Savage, Emma Graham, Bruce Steinert, Joern R. Front Synaptic Neurosci Neuroscience INTRODUCTION: Numerous neurodegenerative diseases are associated with neuronal dysfunction caused by increased redox stress, often linked to aberrant production of redox-active molecules such as nitric oxide (NO) or oxygen free radicals. One such protein affected by redox-mediated changes is the glycolytic enzyme triose-phosphate isomerase (TPI), which has been shown to undergo 3-nitrotyrosination (a NO-mediated post-translational modification) rendering it inactive. The resulting neuronal changes caused by this modification are not well understood. However, associated glycation-induced cytotoxicity has been reported, thus potentially causing neuronal and synaptic dysfunction via compromising synaptic vesicle recycling. METHODS: This work uses Drosophila melanogaster to identify the impacts of altered TPI activity on neuronal physiology, linking aberrant TPI function and redox stress to neuronal defects. We used Drosophila mutants expressing a missense allele of the TPI protein, M81T, identified in a previous screen and resulting in an inactive mutant of the TPI protein (TPI(M81T), wstd(1)). We assessed synaptic physiology at the glutamatergic Drosophila neuromuscular junction (NMJ), synapse morphology and behavioural phenotypes, as well as impacts on longevity. RESULTS: Electrophysiological recordings of evoked and spontaneous excitatory junctional currents, alongside high frequency train stimulations and recovery protocols, were applied to investigate synaptic depletion and subsequent recovery. Single synaptic currents were unaltered in the presence of the wstd(1) mutation, but frequencies of spontaneous events were reduced. Wstd(1) larvae also showed enhanced vesicle depletion rates at higher frequency stimulation, and subsequent recovery times for evoked synaptic responses were prolonged. A computational model showed that TPI mutant larvae exhibited a significant decline in activity-dependent vesicle recycling, which manifests itself as increased recovery times for the readily-releasable vesicle pool. Confocal images of NMJs showed no morphological or developmental differences between wild-type and wstd(1) but TPI mutants exhibited learning impairments as assessed by olfactory associative learning assays. DISCUSSION: Our data suggests that the wstd(1) phenotype is partially due to altered vesicle dynamics, involving a reduced vesicle pool replenishment, and altered endo/exocytosis processes. This may result in learning and memory impairments and neuronal dysfunction potentially also presenting a contributing factor to other reported neuronal phenotypes. Frontiers Media S.A. 2023-02-28 /pmc/articles/PMC10011161/ /pubmed/36926383 http://dx.doi.org/10.3389/fnsyn.2023.1124061 Text en Copyright © 2023 Stone, Cujic, Rowlett, Aderhold, Savage, Graham and Steinert. https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Neuroscience
Stone, Aelfwin
Cujic, Oliver
Rowlett, Angel
Aderhold, Sophia
Savage, Emma
Graham, Bruce
Steinert, Joern R.
Triose-phosphate isomerase deficiency is associated with a dysregulation of synaptic vesicle recycling in Drosophila melanogaster
title Triose-phosphate isomerase deficiency is associated with a dysregulation of synaptic vesicle recycling in Drosophila melanogaster
title_full Triose-phosphate isomerase deficiency is associated with a dysregulation of synaptic vesicle recycling in Drosophila melanogaster
title_fullStr Triose-phosphate isomerase deficiency is associated with a dysregulation of synaptic vesicle recycling in Drosophila melanogaster
title_full_unstemmed Triose-phosphate isomerase deficiency is associated with a dysregulation of synaptic vesicle recycling in Drosophila melanogaster
title_short Triose-phosphate isomerase deficiency is associated with a dysregulation of synaptic vesicle recycling in Drosophila melanogaster
title_sort triose-phosphate isomerase deficiency is associated with a dysregulation of synaptic vesicle recycling in drosophila melanogaster
topic Neuroscience
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10011161/
https://www.ncbi.nlm.nih.gov/pubmed/36926383
http://dx.doi.org/10.3389/fnsyn.2023.1124061
work_keys_str_mv AT stoneaelfwin triosephosphateisomerasedeficiencyisassociatedwithadysregulationofsynapticvesiclerecyclingindrosophilamelanogaster
AT cujicoliver triosephosphateisomerasedeficiencyisassociatedwithadysregulationofsynapticvesiclerecyclingindrosophilamelanogaster
AT rowlettangel triosephosphateisomerasedeficiencyisassociatedwithadysregulationofsynapticvesiclerecyclingindrosophilamelanogaster
AT aderholdsophia triosephosphateisomerasedeficiencyisassociatedwithadysregulationofsynapticvesiclerecyclingindrosophilamelanogaster
AT savageemma triosephosphateisomerasedeficiencyisassociatedwithadysregulationofsynapticvesiclerecyclingindrosophilamelanogaster
AT grahambruce triosephosphateisomerasedeficiencyisassociatedwithadysregulationofsynapticvesiclerecyclingindrosophilamelanogaster
AT steinertjoernr triosephosphateisomerasedeficiencyisassociatedwithadysregulationofsynapticvesiclerecyclingindrosophilamelanogaster