Biology subjects

Feiguin, F.

Publications and source records attributed to Feiguin, F..

4 recordsLinked to original sources

bioRxiv2023

Su(var)3-9 mediates age-dependent increase in H3K9 methylation on TDP-43 promoter triggering neurodegeneration

Aging progressively modifies the physiological balance of the organism increasing susceptibility to both genetic and sporadic neurodegenerative diseases. These changes include epigenetic chromatin remodeling events that may modify gene transcription. However, how aging interconnects with disease-causing genes is not well known. Here, we found that Su(var)3-9 causes increased methylation of histone H3K9 in the promoter region of TDP-43, the most frequently altered factor in amyotrophic lateral sclerosis (ALS), affecting the mRNA and protein expression levels of this gene through epigenetic modifications in chromatin organization that appear to be conserved in aged Drosophila brains, mouse and human cells. Remarkably, augmented Su(var)3-9 activity causes a decrease in TDP-43 expression followed by early defects in locomotor activities. In contrast, decreasing Su(var)3-9 action promotes higher levels of TDP-43 expression and reinvigorates motility parameters in old flies, uncovering a novel role of this enzyme in regulating TDP-43 expression and locomotor senescence. The data indicate how conserved epigenetic mechanisms may link aging with neuronal diseases and suggest that Su(var)3-9 may play a role in the pathogenesis of ALS.

molecular biology↗

bioRxiv2021

TDP-43 regulates GAD1 mRNA splicing and GABA signaling in Drosophila brains

Alterations in the function of the RNA-binding protein TDP-43 is largely associated with the pathogenesis of amyotrophic lateral sclerosis (ALS), a devastating disease of the human motor system that leads to motoneurons degeneration and reduced life expectancy by molecular mechanisms not well known. Regarding to that, we found that the expression levels of the glutamic acid decarboxylase enzyme (GAD1), responsible to convert glutamate to {gamma}-aminobutyric acid (GABA), were downregulated in TBPH-null flies and motoneurons derived from ALS patients carrying mutations in TDP-43 suggesting that defects in the regulation of GAD1 may lead to neurodegeneration by affecting neurotransmitter balance. In this study, we observed that TBPH was required to regulate GAD1 pre-mRNA splicing and GABA levels in Drosophila brains. Interestingly, we discovered that pharmacological treatments aimed to modulate GABA neurotransmission were able to revert locomotion deficiencies in TBPH-minus flies revealing novel mechanisms and therapeutic strategies in ALS.

neuroscience↗

bioRxiv2019

TDP-43 regulates the expression levels of Disc-large in skeletal muscles to promote the assemble of the neuromuscular synapses in Drosophila

BackgroundAlterations in the intracellular distribution of TDP-43 were observed in the skeletal muscles of patients suffering from ALS. However, it is not clear whether these modifications play an active role in the disease or represent a physiological adaptation to muscles homeostasis.\n\nResultTo answer these questions, we modulated the activity of this protein in Drosophila muscles and observed that TDP-43 was required in these tissues to promote the formation and growth of the neuromuscular synapses. Moreover, we identified that TDP-43 regulates the expression levels of Disc-large (Dlg) and demonstrated that the modulation of Dlg activity, in skeletal muscles or motoneurons, was sufficient to recover the TDP-43-null locomotive and synaptic defects in flies. Additionally, we found that similar mechanisms are conserved in human cell lines and present in tissues derived from ALS patients.\n\nConclusionsOur results uncover the physiological role of TDP-43 in skeletal muscles as well as the mechanisms behind the autonomous and non-autonomous behavior of this protein in the organization of the neuromuscular synapses.

neuroscience↗

bioRxiv2019

Endogenous TDP-43 prevents retrotransposons activation through Dicer-2 activity and the RNA silencing machinery in Drosophila

The aberrant expression of retrotransposable elements (RTEs) was observed in different neurodegenerative diseases including amyotrophic lateral sclerosis (ALS), a terminal disorder characterized by functional alterations in the small RNA-binding protein TDP-43, suggesting that these events might be connected. Using genome wide gene expression profiles, we detected RTEs highly upregulated in TDP-43-null Drosophila heads while, the genetic rescue of TDP-43 function reverted these modifications. Furthermore, we found that TDP-43 modulates the small interfering RNA (siRNA) silencing machinery responsible for RTEs repression. Molecularly, we observed that TDP-43 regulates the expression levels of Dicer-2 by direct protein-mRNA interactions in vivo. Accordingly, the genetic or pharmacological recovery of Dicer-2 activity was sufficient to repress retrotransposons activation and revert the neurodegeneration in TDP-43-null Drosophila motoneurons. Our results, describe a novel physiological role of endogenous TDP-43 in the prevention of RTEs-induced neurodegeneration through the modulation of Dicer-2 activity and the siRNA pathway.

cell biology↗