Biology subjects

Mione, M.

Publications and source records attributed to Mione, M..

5 recordsLinked to original sources

bioRxiv2025

Telomeric antisense oligonucleotides reduce premature aging phenotypes in telomerase mutant zebrafish

Telomerase activity is restricted in somatic cells, resulting in progressive telomere shortening. Telomere erosion eventually activates the DNA damage response (DDR), inducing cell-cycle arrest and cellular senescence or apoptosis. We previously reported that telomere dysfunction induces the transcription of telomeric non-coding RNAs (tncRNAs) which are critical mediators of DDR activation. Blocking tncRNAs with telomeric antisense oligonucleotides (tASOs) suppresses in vivo DDR signaling and its downstream effects. Here, we show that tASO-mediated inhibition of telomeric DDR in second-generation tert-/- zebrafish embryos with critically short telomeres leads to improved developmental outcomes and rescues premature aging phenotypes, including enhanced survival. Notably, a single tASO treatment administered at the one-cell stage of first-generation tert-/- embryos leads to enhanced fertility observed in 6-month-old adults. Overall, these findings demonstrate that tASO-based inhibition of telomeric DDR is sufficient to effectively rescue premature aging phenotypes in zebrafish.

pathology↗

bioRxiv2025

A TranSNP in the DDIT4 mRNA can impact its translation efficiency and modulate p53-dependent responses in cancer cells

Relatively few studies have examined the link between SNPs and mRNA translation, despite the established importance of translational regulation in shaping cell phenotypes. We developed a pipeline analyzing the allelic imbalance in total and polysome-bound mRNAs from paired RNA-seq data of HCT116 cells and identified 40 candidate tranSNPs, i.e. SNPs associated with allele-specific translation. Among them, the SNP rs1053639 (T/A) on DNA damage-inducible transcript 4 (DDIT4) 3UTR was identified, with the reference T allele showing a higher polysome association. rs1053639 TT clones generated by genome editing exhibited significantly higher DDIT4 protein levels than AA ones. The difference in DDIT4 proteins was even greater when cells were treated with Thapsigargin or Nutlin, two perturbations that induce DDIT4 transcription. The RNA-binding protein RBMX influenced these allele-dependent differences in DDIT4 protein expression, as shown by RNA-EMSA, RIP, and smiFISH assays. RBMX depletion reduced DDIT4 protein in TT clones to the AA levels. Functionally, TT clones more effectively repressed mTORC1 under ER stress, while AA clones outcompeted TT clones in vitro or when injected in zebrafish embryos. RBMX depletion increased the fitness of TT cells in co-culture experiments. The rs1053639 AA genotype, under a recessive model, correlates with poor prognosis in TCGA cancer data. Key points- Translatome analysis in HCT116 cells revealed allele-specific mRNA translation for 40 SNPs - rs1053639 (T/A) in DDIT4 3UTR showed allelic differences in mRNA localization & protein expression - AA cells showed weaker mTOR inhibition & higher proliferation; AA individuals had poorer prognosis

molecular biology↗

bioRxiv2021

Telomerase and Alternative Lengthening of Telomeres coexist in the regenerating zebrafish caudal fins

Telomeres are essential for chromosome protection and genomic stability, and telomerase function is critical to organ homeostasis. Zebrafish has become a useful vertebrate model for understanding the cellular and molecular mechanisms of regeneration. The regeneration capacity of the caudal fin of wild-type zebrafish is not affected by repetitive amputation, but the behavior of telomeres during this process has not yet been studied. In this study, the regeneration process was characterized in a telomerase deficient zebrafish model. Moreover, the regenerative capacity after repetitive amputations and at different ages was studied. Regenerative efficiency decreases with aging in all genotypes and surprisingly, telomere length is maintained even in telomerase deficient genotypes. Our results suggest that telomere length can be maintained by the regenerating cells through the recombination-mediated Alternative Lengthening of Telomeres (ALT) pathway, which is likely to support high rates of cell proliferation during the tailfin regeneration process. As far as we know, this is the first animal model to study ALT mechanism in regeneration, which opens a wealth of possibilities to study new treatments of ALT dependent processes.

genetics↗

bioRxiv2021

Disease modeling by efficient genome editing using a near PAM-less base editor in vivo.

Base Editors are emerging as an innovative technology to introduce point mutations in complex genomes. So far, the requirement of an NGG Protospacer Adjacent Motif (PAM) at a suitable position often limits the editing possibility to model human pathological mutations in animals. Here we show that, using the CBE4max-SpRY variant recognizing the NRN PAM sequence, we could introduce point mutations for the first time in an animal model and achieved up to 100% efficiency, thus drastically increasing the base editing possibilities. With this near PAM-less base editor we could simultaneously mutate several genes and developed a co-selection method to identify the most edited embryos based on a simple visual screening. Finally, we applied our method to create a new zebrafish model for melanoma predisposition based on the simultaneous editing of multiple genes. Altogether, our results considerably expand the Base Editor application to introduce human disease-causing mutations in zebrafish.

developmental biology↗

bioRxiv2020

Precise base editing for the in vivo study of developmental signaling and human pathologies in zebrafish

While zebrafish is emerging as a new model system to study human diseases, an efficient methodology to generate precise point mutations at high efficiency is still lacking. Here we show that base editors can generate C-to-T point mutations with high efficiencies without other unwanted on-target mutations. In addition, we established a new editor variant recognizing an NAA PAM, expanding the base editing possibilities in zebrafish. Using these approaches, we first generated a base change in the ctnnb1 gene, mimicking oncogenic mutations of the human gene known to result in constitutive activation of endogenous Wnt signaling. Additionally, we precisely targeted several cancer-associated genes among which cbl. With this last target we created a new zebrafish dwarfism model. Together our findings expand the potential of zebrafish as a model system allowing new approaches for the endogenous modulation of cell signaling pathways and the generation of precise models of human genetic disease associated-mutations.

developmental biology↗