Biology subjects

CORRE, G.

Publications and source records attributed to CORRE, G..

3 recordsLinked to original sources

bioRxiv2025

Base editing of β0 thalassemia mutations as a therapeutic strategy for β-hemoglobinopathies: efficacy and genotoxicity studies

Gene therapy has emerged as a promising curative treatment for {beta}-hemoglobinopathies, the most common genetic disorders worldwide. However, current approved approaches still have some limitations in terms of safety and efficacy. Here, we used highly processive adenine base editors (ABE) variants to precisely correct some of the most prevalent and severe {beta}-thalassemia-causing mutations in the {beta}-globin gene. Efficient editing of hematopoietic stem/progenitor cells (HSPCs) led to potent {beta}-globin expression in their erythroid progeny and persistent correction of both {beta}-thalassemia and sickle cell-{beta}-thalassemia phenotypes. Safety of this strategy was confirmed in HSPCs in vitro and in vivo by the absence of gene dysregulation or any meaningful impact on the DNA mutational burden, the RNA deamination level, the {beta}-globin gene locus integrity and the clonality of the HSPC graft. Overall, base editing-mediated gene correction is a safe and effective strategy for treating {beta}-hemoglobinopathies. One sentence summaryPreclinical safety and efficacy studies of a new gene therapy approach for patients with severe {beta}-hemoglobinopathies.

genetics↗

bioRxiv2025

A NEW DYSTROPHIN DEFICIENT RAT MODEL MIRRORING EXON SKIPPING IN PATIENTS WITH DMD EXON 45 DELETIONS

Mutations in the dystrophin (DMD) gene can cause a spectrum of muscle-wasting disorders ranging from the milder Becker muscular dystrophy (BMD) to the more severe Duchenne muscular dystrophy (DMD). Among these, exon 45 deletion is the most frequently reported single exon deletion in DMD patients worldwide. In this study, we generated a novel rat model with an exon 45 deletion using CRISPR/Cas9 technology. The Dmd{Delta}45 rat recapitulate key clinical and molecular features of DMD, including progressive skeletal muscle degeneration, cardiac dysfunction, cognitive deficits, elevated circulating muscle damage biomarkers, impaired muscle function, and overall reduced lifespan. Transcriptomics analyses confirmed the deletion of exon 45 and revealed gene expression patterns consistent with dystrophin deficiency. In the skeletal muscle, RNA-seq profiles demonstrated a transition from early stress responses and regenerative activity at 6 months to chronic inflammation, fibrosis, and metabolic dysfunction by 12 months. Similarly, the cardiac transcriptomic shifted from an early inflammatory and stress-responsive state to one characterized by fibrotic remodelling and metabolic impairment. Despite these pathological features, the Dmd{Delta}45 rats exhibited a milder phenotype than other DMD rat models. This attenuation may be attributed to spontaneous exon 44 skipping, which partially restores the reading frame and results in an age-dependent increase in revertant dystrophin-positive fibres. Further analysis indicated downregulation of spliceosome-related genes, suggesting a potential mechanism driving exon skipping in this model. In summary, the Dmd{Delta}45 rat represents a valuable model for investigating both the molecular determinants of phenotypic variability and the endogenous mechanisms of exon skipping. These findings offer important insights for the development of personalized exon-skipping therapies, particularly for DMD patients with exon 45 deletions.

genetics↗

bioRxiv2024

Multiplex base editing of BCL11A regulatory elements to treat sickle cell disease

Sickle cell disease (SCD) is a genetic anemia caused by the production of an abnormal adult hemoglobin. The clinical severity is lessened by elevated fetal hemoglobin (HbF) production in adulthood. A promising therapy is the transplantation of autologous, hematopoietic stem/progenitor cells (HSPCs) treated with CRISPR/Cas9 to downregulate the HbF repressor BCL11A via generation of double strand breaks (DSBs) in the +58-kb erythroid-specific enhancer. Here, to further enhance HbF production without increasing the mutagenic load, we targeted both +58-kb and +55-kb BCL11A erythroid-specific enhancers using base editors. We systematically dissected DNA motifs recognized by the key transcriptional activators within these regions and identified the critical nucleotides required for activator binding. Multiplex base editing of these residues was efficient and safe and generated no or little DSBs and genomic rearrangements. We observed substantial HbF reactivation, exceeding the levels achieved using the CRISPR/Cas9 nuclease-based strategy, thus efficiently rescuing the sickling phenotype. Multiplex base editing was efficient in long-term repopulating HSPCs and resulted in potent HbF reactivation in vivo. In summary, these results show that multiplex base editing of BCL11A erythroid-specific enhancers is a safe and potent strategy for treating sickle cell disease.

molecular biology↗