Biology subjects

Crerar, H.

Publications and source records attributed to Crerar, H..

4 recordsLinked to original sources

bioRxiv2026

Toxicity of MAPT 4R RNA Contributes to Motor Neuron Degeneration in ALS

MAPT (Tau) dysregulation is implicated in several neurodegenerative diseases, but its contribution to amyotrophic lateral sclerosis (ALS) is poorly understood. Here we show that mRNA isoforms encoding 4-repeat (4R) Tau are upregulated and cytoplasmically enriched in iPSC-derived motor neurons (MNs) from VCP-mutant and sporadic ALS, without a corresponding change in Tau protein. Using splice-switching antisense oligonucleotides and isoform-specific siRNAs, we find that enhanced 4R expression reduces MN viability, whereas its selective knockdown improves survival, with kinetics more consistent with an RNA-intrinsic effect than altered protein synthesis. Exon 10-containing MAPT RNA shows increased predicted secondary structure, self-association and altered Tau biocondensation in vitro. In post-mortem ALS cervical spinal cord, increased relative exon 10 usage is associated with a higher-risk clinical phenotype and shorter disease duration These findings identify an isoform-specific contribution of MAPT to MN vulnerability in ALS and nominate 4R MAPT RNA as a therapeutic target.

neuroscience↗

bioRxiv2021

Diminished miRNA activity is associated with aberrant cytoplasmic intron retention in ALS pathogenesis

Intron retention (IR) is now recognized as a dominant splicing event during motor neuron (MN) development, however the role and regulation of intron-retaining transcripts (IRTs) localized to the cytoplasm remain particularly understudied. By resolving the spatiotemporal dynamics of IR underlying distinct stages of MN lineage restriction, we identify a cytoplasmic group of IRTs that is not associated with reduced expression of their own genes but instead with an upregulation of predicted target genes of specific miRNAs, the motifs of which are enriched within the intronic sequences of this group. Next, we show that ALS-causing VCP mutations lead to a selective increase in IR of this particular class of introns. This in turn temporally coincides with an increase in the expression level of predicted target genes of these miRNAs, providing a potential mechanistic insight into ALS pathogenesis. Altogether, we propose a novel role for the cytoplasmic intronic sequences in regulating miRNA activity through miRNA sequestration, which potentially contributes to ALS pathogenesis.

neuroscience↗

bioRxiv2020

An aberrant cytoplasmic intron retention programme is a blueprint for ALS-related RBP mislocalization

We recently described aberrant cytoplasmic SFPQ intron-retaining transcripts (IRTs) and concurrent SFPQ protein mislocalization as a new hallmark of amyotrophic lateral sclerosis (ALS). However the generalizability and potential roles of cytoplasmic IRTs in health and disease remain unclear. Here, using time-resolved deep-sequencing of nuclear and cytoplasmic fractions of hiPSCs undergoing motor neurogenesis, we reveal that ALS-causing VCP gene mutations lead to compartment-specific aberrant accumulation of IRTs. Specifically, we identify >100 IRTs with increased cytoplasmic (but not nuclear) abundance in ALS samples. Furthermore, these aberrant cytoplasmic IRTs possess sequence-specific attributes and differential predicted binding affinity to RNA binding proteins (RBPs). Remarkably, TDP-43, SFPQ and FUS - RBPs known for nuclear-to-cytoplasmic mislocalization in ALS - avidly and specifically bind to this aberrant cytoplasmic pool of IRTs, as opposed to any individual IRT. Our data are therefore consistent with a novel role for cytoplasmic IRTs in regulating compartment-specific protein abundance. This study provides new molecular insight into potential pathomechanisms underlying ALS and highlights aberrant cytoplasmic IRTs as potential therapeutic targets. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=181 SRC="FIGDIR/small/211557v2_ufig1.gif" ALT="Figure 1"> View larger version (68K): org.highwire.dtl.DTLVardef@153fc1eorg.highwire.dtl.DTLVardef@cd3506org.highwire.dtl.DTLVardef@544868org.highwire.dtl.DTLVardef@15ddb68_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2017

3’UTR Remodelling of Axonal Transcripts in Sympathetic Neurons

The 3 untranslated regions (3UTRs) of messenger RNAs (mRNA) are non-coding sequences that regulate several aspects of mRNA metabolism, including intracellular localisation and translation. Here, we show that in sympathetic neuron axons, the 3UTRs of many transcripts undergo cleavage, generating both translatable isoforms expressing a shorter 3UTR, and 3UTR fragments. 3end RNA sequencing indicated that 3UTR cleavage is a potentially widespread event in axons, which is mediated by a protein complex containing the endonuclease Ago2 and the RNA binding protein HuD. Analysis of the Inositol monophosphatase 1 (Impa1) mRNA revealed that a stem loop structure within the 3UTR is necessary for Ago2 cleavage. Thus, remodeling of the 3UTR provides an alternative mechanism that simultaneously regulates local protein synthesis and generates a new class of 3UTR RNAs with yet unknown functions.

neuroscience↗