Biology subjects

Vaine, C. A.

Publications and source records attributed to Vaine, C. A..

3 recordsLinked to original sources

bioRxiv2025

Genome writing to dissect consequences of SVA retrotransposon disease X-Linked Dystonia Parkinsonism

Human retrotransposon insertions are often associated with diseases. In the case of the neurodegenerative X-Linked Dystonia-Parkinsonism disease, a human-specific SINE-VNTR-Alu subfamily F retrotransposon was inserted in intron 32 of the TAF1 gene. Here, we genomically rewrote a portion of the mouse Taf1 allele with the corresponding 78-kb XDP patient derived TAF1 allele. In mESCs, the presence of the intronic SVAs--rather than the hybrid gene structure--reduces hyTAF1 levels. This leads to transcriptional downregulation of genes with TATA box enriched in their promoters and triggering apoptosis. Chromatin and transcriptome profiling revealed that intronic SVAs are actively transcribed, forming barriers that likely impede transcription elongation. In mice, neuronal lineage TAF1 humanization resulted lethality of male progeny within two months. XDP male mice had severe atrophy centered on the striatum--the same affected brain region in XDP patients. Lastly, CRISPRa-mediated activation of hyTAF1 restored mESC viability, suggesting boosting TAF1 transcription as a therapeutic approach.

genetics↗

bioRxiv2023

ZNF91 is an endogenous repressor of the molecular phenotype associated with X-linked dystonia-parkinsonism (XDP)

BackgroundX-linked dystonia-parkinsonism (XDP) is a severe neurodegenerative disorder resulting from the insertion of an intronic SINE-Alu-VNTR (SVA) retrotransposon in the TAF1 gene. Recent research has revealed that the pathogenic XDP-SVA insertion leads to dysregulation of TAF1 transcription, including increased intron retention and decreased expression of exons surrounding the insertion. The Kruppel-associated box (KRAB) zinc finger protein, ZNF91, is a critical repressor of SVA retrotransposons. However, it remains unclear whether ZNF91 is able to repress the XDP-SVA insertion and how this influences the XDP-associated molecular phenotype. In this study, we investigate the role of ZNF91 in repressing the XDP-SVA insertion and its impact on the molecular phenotype associated with XDP. MethodsHere, we used CRISPR/Cas9 to genetically delete ZNF91 in induced pluripotent stem cell (iPSC) lines derived from XDP patients, as well as isogenic control iPSC lines that lack the XDP-SVA insertion. Total RNA sequencing and capture RNA-sequencing were used to confirm ZNF91 deletion and to assess TAF1 transcriptional changes between conditions. Furthermore, publicly available transcriptomic data from whole blood and different brain regions were used to assess ZNF91 expression levels across ages. ResultsWe found that genetic deletion of ZNF91 exacerbates the molecular phenotype associated with the XDP-SVA insertion in patient cells, while no difference was observed when ZNF91 was deleted from isogenic control cells. Additionally, we observed a significant age-related reduction in ZNF91 expression in whole blood and brain, indicating a potential role of ZNF91 in the age-dependent onset of XDP. ConclusionsThese findings indicate that ZNF91 plays a crucial role in controlling the molecular phenotype associated with XDP. Since ZNF91 is a critical epigenetic repressor of SVAs, this suggests that epigenetic silencing of the XDP-SVA minimizes the severity of the molecular phenotype. Our results showing that ZNF91 expression levels significantly decrease with age provide a potential explanation for the age-related progressive neurodegenerative character of XDP. Collectively, our study provides important insights into the protective role of ZNF91 in XDP pathogenesis and suggests that modulating ZNF91 levels or targeted repression of the XDP-SVA could be novel therapeutic strategies worth exploring.

neuroscience↗

bioRxiv2017

Dissecting the Causal Mechanism of X-Linked Dystonia-Parkinsonism by Integrating Genome and Transcriptome Assembly

X-linked Dystonia-Parkinsonism (XDP) is a Mendelian neurodegenerative disease endemic to the Philippines. We integrated genome and transcriptome assembly with induced pluripotent stem cell-based modeling to identify the XDP causal locus and potential pathogenic mechanism. Genome sequencing identified novel variation that was shared by all probands and three recombination events that narrowed the causal locus to a genomic segment including TAF1. Transcriptome assembly in neural derivative cells discovered novel TAF1 transcripts, including a truncated transcript exclusively observed in probands that involved aberrant splicing and intron retention (IR) associated with a SINE-VNTR-Alu (SVA)-type retrotransposon insertion. This IR correlated with decreased expression of the predominant TAF1 transcript and altered expression of neurodevelopmental genes; both the IR and aberrant TAF1 expression patterns were rescued by CRISPR/Cas9 excision of the SVA. These data suggest a unique genomic cause of XDP and may provide a roadmap for integrative genomic studies in other unsolved Mendelian disorders.\n\nHighlights O_LIGenome assembly narrows the XDP causal locus to a segment including TAF1\nC_LIO_LIXDP-specific SVA insertion induces intron retention and down-regulation of TAF1\nC_LIO_LICRISPR/Cas9 excision of SVA rescues aberrant splicing and cTAF1 expression in XDP\nC_LIO_LIGene networks perturbed in proband cells associate to synapse and neurodevelopment\nC_LI

genomics↗