bioRxiv Science⌕ Search

Biology subjects

Terzibasi Tozzini, E.

Publications and source records attributed to Terzibasi Tozzini, E..

3 recordsLinked to original sources

Aging is associated with a degeneration of noradrenergic-, but not dopaminergic-neurons, in the short-lived killifish Nothobranchius furzeri.

Parkinsons disease (PD) is characterized by phosphorylation and aggregation of the protein -Synuclein and ensuing neuronal death progressing from the noradrenergic locus coeruleus to midbrain dopaminergic neurons. In 2019, Matsui and colleagues reported in Cell Reports a spontaneous age-dependent degeneration of dopaminergic neurons and an even greater neurodegeneration of the noradrenergic neurons in the short-lived killifish Nothobranchius furzeri. Given the great possible relevance of a spontaneous model for PD, we set to confirm their results by whole-brain clarification and 3D nuclei reconstruction to quantify total cell numbers. We observed an age dependent neurodegeneration limited to the locus coeruleus and not involving the posterior tuberculum. In addition, we observed the presence of phospho-Synuclein in the soma of locus coeruleus neurons detectable already at a young age and increasing during aging. Our result demonstrates that N. furzeri models the early stages of PD, but not the degeneration of dopaminergic neurons.

neuroscience↗

New lessons on TDP-43 from the killifish N. furzeri

Frontotemporal dementia and amyotrophic lateral sclerosis are fatal and incurable neurodegenerative diseases linked to the pathological aggregation of the TDP-43 protein. This is an essential DNA/RNA binding protein involved in transcription regulation, pre-RNA processing and RNA transport. Having suitable animal models to study the mechanisms of TDP-43 aggregation is crucial to develop treatments against disease. We have previously demonstrated that the killifish Nothobranchius furzeri offers the unique advantage as a model system that it is an organism with compressed lifespan and a conserved ageing phenotype that develops within months, making this organism the available shortest-lived vertebrate with a clear ageing phenotype. Here, we show that the two paralogs of TDP-43 from the killifish N. furzeri share high sequence homology with the human protein and recapitulate its cellular and biophysical behaviour. We prove that, during ageing, N. furzeri TDP-43 spontaneously forms insoluble intracellular TDP-43 aggregates that have amyloid characteristics and colocalize with the stress granule core protein G3BP. Our results propose this organism as a valuable model of TDP-43-related pathologies and show that even minute differences between the human and N. furzeri proteins may help to shed new light onto the role of TDP-43 in RNA recognition and granule formation.

neuroscience↗

Reduced proteasome activity in the aging brain results in ribosome stoichiometry loss and aggregation

A progressive loss of protein homeostasis is characteristic of aging and a driver of neurodegeneration. To investigate this process quantitatively, we characterized proteome dynamics during brain aging in the short-lived vertebrate Nothobranchius furzeri combining transcriptomics and proteomics. We detected a progressive reduction in the correlation between protein and mRNA, mainly due to post-transcriptional mechanisms that account for over 40% of the age-regulated proteins. These changes cause a progressive loss of stoichiometry in several protein complexes, including ribosomes, which show impaired assembly / dis-assembly and are enriched in protein aggregates in old brains. Mechanistically, we show that reduction of proteasome activity is an early event during brain aging and is sufficient to induce proteomic signatures of aging and loss of stoichiometry in vivo. Using longitudinal transcriptomic data, we show that the magnitude of early life decline in proteasome levels is the major risk factor for mortality. Our work defines causative events in the aging process that can be targeted to prevent loss of protein homeostasis and delay the onset of age-related neurodegeneration. HighlightsO_LIProgressive loss of stoichiometry affects multiple protein complexes C_LIO_LIRibosomes aggregate in old brains C_LIO_LIPartial reduction of proteasome activity is sufficient to induce loss of stoichiometry C_LIO_LIReduced proteasome levels are a major risk factor for early death in killifish C_LI

systems biology↗