CRISPR/Cas9-based double-strand oligonucleotide insertion strategy corrects metabolic abnormalities in murine glycogen storage disease type-Ia

Lipid Nanoparticles for Delivery of CRISPR Gene Editing Components

Gene editing has emerged as a promising therapeutic option for treating genetic diseases. However, a central challenge in the field is the safe and efficient delivery of these large editing tools, especially in vivo. Lipid nanoparticles (LNPs) are attractive nonviral vectors due to their low immunogenicity and high delivery efficiency. To maximize editing efficiency, LNPs should efficiently protect gene editing components against multiple biological barriers and release them into the cytoplasm of target cells. In this review, the widely used CRISPR gene editing systems are first overviewed. Then, each component of LNPs, as well as their effects on delivery, are systematically discussed. Following this, the current LNP engineering strategies to achieve non-liver targeting are summarized. Finally, preclinical and clinical applications of LNPs for in vivo genome editing are highlighted, and perspectives for the future development of LNPs are provided.

The role of glucose-6-phosphatase activity in glucose homeostasis and its potential for diabetes therapy

Glucose-6-phosphatase catalytic subunit (G6PC)1 and G6PC2 are crucial for glucose metabolism, regulating processes like glycolysis, gluconeogenesis, and glycogenolysis. Despite their structural and functional similarities, G6PC1 and G6PC2 exhibit distinct tissue-specific expression patterns, G6P hydrolysis kinetics, and physiological functions. This review provides a comprehensive overview of their enzymology and distinct roles in glucose homeostasis. We examine how inactivating mutations in G6PC1 lead to glycogen storage disease, and how elevated G6PC1 and G6PC2 expression can affect the incidence of diabetic complications, risk for type 2 diabetes mellitus (T2DM) and various cancers. We also discuss the potential of inhibiting G6PC1 and G6PC2 to protect against complications from elevated blood glucose levels, and highlight drug development efforts targeting G6PC1 and G6PC2, and the therapeutic potential of inhibitors for disease prevention.

Base-editing corrects metabolic abnormalities in a humanized mouse model for glycogen storage disease type-Ia

Glycogen storage disease type-Ia patients, deficient in the G6PC1 gene encoding glucose-6-phosphatase-α, lack blood glucose control, resulting in life-threatening hypoglycemia. Here we show our humanized mouse model, huR83C, carrying the pathogenic G6PC1-R83C variant displays the phenotype of glycogen storage disease type-Ia and dies prematurely. We evaluate the efficacy of BEAM-301, a formulation of lipid nanoparticles containing a newly-engineered adenine base editor, to correct the G6PC1-R83C variant in huR83C mice and monitor phenotypic correction through one year. BEAM-301 can correct up to ~60% of the G6PC1-R83C variant in liver cells, restores blood glucose control, improves metabolic abnormalities of the disease, and confers long-term survival to the mice. Interestingly, just ~10% base correction is therapeutic. The durable pharmacological efficacy of base editing in huR83C mice supports the development of BEAM-301 as a potential therapeutic for homozygous and compound heterozygous glycogen storage disease type-Ia patients carrying the G6PC1-R83C variant.

Targeted Gene Insertion: The Cutting Edge of CRISPR Drug Development with Hemophilia as a Highlight

The remarkable advance in gene editing technology presents unparalleled opportunities for transforming medicine and finding cures for hereditary diseases. Human trials of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein-9 nuclease (Cas9)-based therapeutics have demonstrated promising results in disrupting or deleting target sequences to treat specific diseases. However, the potential of targeted gene insertion approaches, which offer distinct advantages over disruption/deletion methods, remains largely unexplored in human trials due to intricate technical obstacles and safety concerns. This paper reviews the recent advances in preclinical studies demonstrating in vivo targeted gene insertion for therapeutic benefits, targeting somatic solid tissues through systemic delivery. With a specific emphasis on hemophilia as a prominent disease model, we highlight advancements in insertion strategies, including considerations of DNA repair pathways, targeting site selection, and donor design. Furthermore, we discuss the complex challenges and recent breakthroughs that offer valuable insights for progressing towards clinical trials.