In a groundbreaking new study, researchers have demonstrated the potential of in vivo base editing to correct the devastating liver pathophysiology and peroxisomal dysfunction characteristic of Zellweger spectrum disorder (ZSD), a severe genetic condition with limited treatment options. Published in Nature Biomedical Engineering, this pioneering work presents a major leap forward in the application of precision genome editing technologies for the treatment of complex metabolic disorders. By directly correcting disease-causing mutations within a living organism, this approach offers a glimpse into the future of personalized medicine tailored to combating inherited peroxisomal biogenesis disorders.
Zellweger spectrum disorder, a peroxisomal biogenesis disorder, arises from mutations impairing peroxisome formation and function, leading to multiple systemic abnormalities. The liver, one of the primary organs affected by peroxisomal defects, undergoes profound metabolic disruptions, manifesting in severe hepatopathology. Currently, clinical management of ZSD remains largely supportive, with no definitive curative therapies available. The new study capitalizes on the emergent power of base editing — a cutting-edge gene editing technique that enables precise single-nucleotide changes without inducing double-strand DNA breaks — to target the specific genetic mutations underlying ZSD.
The research team engineered a highly efficient adenine base editor (ABE) system capable of converting an A•T base pair to a G•C base pair with minimal off-target effects. By packaging this system into adeno-associated viral (AAV) vectors optimized for liver tropism, the authors achieved robust delivery of the editor directly to hepatocytes in ZSD mouse models. This approach circumvented the challenges posed by conventional CRISPR-Cas9 editing, such as the risk of DNA double-strand breaks and consequent genomic instability, which are especially detrimental in post-mitotic tissues like the liver.
Upon systemic administration of the base editor-carrying AAV vectors, the researchers observed highly efficient correction of the pathogenic mutation within the PEX gene cluster, which is pivotal for peroxisome biogenesis. Importantly, the editing efficiency reached therapeutic thresholds sufficient to alleviate the hallmark biochemical abnormalities characteristic of ZSD, including aberrant very long chain fatty acid (VLCFA) accumulation and deficits in plasmalogen synthesis. Biochemical analyses confirmed restoration of peroxisomal enzyme activities essential for detoxification and lipid metabolism.
A salient aspect of the study is the comprehensive phenotypic rescue observed in treated mice. Beyond molecular corrections, the mice exhibited significant reversal of liver histopathology, marked by reductions in hepatocellular ballooning, inflammation, and fibrosis. Functional assays revealed improved hepatic metabolic function and normalization of serum liver enzyme profiles. Additionally, systemic effects of peroxisomal restoration were evident, including improved neurological function and extended survival rates, underscoring the far-reaching impact of targeted gene correction.
The scientists meticulously evaluated off-target editing and potential adverse effects. Deep sequencing analyses confirmed negligible off-target mutations, reinforcing the precision and safety of the base editor platform. Furthermore, no signs of immunogenicity or vector-related toxicity were detected, addressing a crucial translational barrier for in vivo gene editing therapeutics.
This in vivo base editing approach offers several translational advantages over previous gene therapy strategies for peroxisomal disorders. By permanently correcting the causative point mutation at the DNA level in patient-relevant cells, it eliminates the need for repeated administration or reliance on transient gene expression. The liver’s accessibility and regenerative capacity further enhance the feasibility of this therapeutic strategy, enabling durable and physiologically meaningful correction.
Despite these promising results, clinical translation will require further optimization and rigorous validation in large animal models before human trials are warranted. Challenges such as scaling vector production, ensuring safe dosing regimens, and addressing potential immune responses to the editor system must be carefully addressed. Nonetheless, this study lays a critical foundation for deploying high-precision base editing tools in combatting peroxisomal biogenesis disorders and potentially other monogenic liver diseases.
The implications of this research extend beyond ZSD, signaling a new era in the treatment of inborn errors of metabolism by harnessing the precision and efficacy of next-generation genome editing technologies. It also exemplifies the power of multidisciplinary collaboration, integrating molecular biology, gene therapy vectorology, and clinical pathology to tackle complex genetic diseases at their root cause.
In conclusion, the deployment of in vivo adenine base editing to rescue peroxisome dysfunction and liver pathology in a rigorously validated mouse model represents a landmark accomplishment in the burgeoning field of therapeutic genome editing. As this technology advances toward clinical application, it promises to revolutionize the treatment landscape for patients afflicted with Zellweger spectrum disorders and opens new avenues for treating a wide spectrum of genetic disorders previously deemed untreatable.
Subject of Research:
Genetic correction of liver and systemic peroxisome dysfunction in Zellweger spectrum disorder using in vivo base editing technology.
Article Title:
In vivo base editing rescues liver pathophysiology and peroxisome dysfunction in a mouse model of Zellweger spectrum disorder.
Article References:
Gao, X.D., Presa, M., Duby, J.E. et al. In vivo base editing rescues liver pathophysiology and peroxisome dysfunction in a mouse model of Zellweger spectrum disorder. Nat. Biomed. Eng (2026). https://doi.org/10.1038/s41551-026-01651-5
Image Credits: AI Generated
DOI:
https://doi.org/10.1038/s41551-026-01651-5
