Project description:Adenine and cytosine base editors (ABEs and CBEs) represent a new genome editing technology that allows the programmable installation of A-to-G or C-to-T alterations on DNA. We engineered Streptococcus pyogenes Cas9-based adenine and cytosine base editor (SpACE) that enables efficient simultaneous introduction of A-to-G and C-to-T substitutions in the same base editing window on DNA.
Project description:The majority of known pathogenic point mutations in the human genome are C•G to T•A substitutions. Adenine base editors (ABEs), comprised of nuclease-impaired Cas9 fused to adenine deaminases, enable direct repair of these mutations, making them promising tools for precision in vivo genome editing therapies. However, prior to application in patients, thorough safety and efficacy studies in relevant model organisms are needed. Here, we apply adenine base editing in vivo in the liver of mice and cynomolgus macaques to install a splice site mutation in PCSK9 and reduce blood low-density lipoprotein (LDL) levels, a well-known risk factor for cardiovascular disease. Intravenous delivery of ABE-encoding mRNA and a locus-specific single guide (sg)RNA utilizing lipid nanoparticle (LNP) technology induce up to 67% editing in the liver of mice and up to 34% editing in the liver of macaques, leading to a reduction of plasma PCSK9 and LDL levels. We observed rapid clearance of ABE mRNA after LNP-mediated delivery, and neither sgRNA-dependent nor sgRNA-independent off-target mutations are detected in genomic DNA. Together, our findings support safety and feasibility of adenine base editing to treat patients with monogenetic liver diseases.
Project description:The majority of known pathogenic point mutations in the human genome are C•G to T•A substitutions. Adenine base editors (ABEs), comprised of nuclease-impaired Cas9 fused to adenine deaminases, enable direct repair of these mutations, making them promising tools for precision in vivo genome editing therapies. However, prior to application in patients, thorough safety and efficacy studies in relevant model organisms are needed. Here, we apply adenine base editing in vivo in the liver of mice and cynomolgus macaques to install a splice site mutation in PCSK9 and reduce blood low-density lipoprotein (LDL) levels, a well-known risk factor for cardiovascular disease. Intravenous delivery of ABE-encoding mRNA and a locus-specific single guide (sg)RNA utilizing lipid nanoparticle (LNP) technology induce up to 67% editing in the liver of mice and up to 34% editing in the liver of macaques, leading to a reduction of plasma PCSK9 and LDL levels. We observed rapid clearance of ABE mRNA after LNP-mediated delivery, and neither sgRNA-dependent nor sgRNA-independent off-target mutations are detected in genomic DNA. Together, our findings support safety and feasibility of adenine base editing to treat patients with monogenetic liver diseases.
2021-04-13 | GSE168363 | GEO
Project description:Hyperactive nickase activity improves adenine base editing
Project description:Adenosine base editing to recreate the HPFH mutations is a promising approach to induce HbF. To measure Cas-independent off-target editing of mRNA, we electroporated CD34+ cells from three different donors with RNP consisting of ABE7.10 or ABE8e complexed with the -globin −175 A>G targeting sgRNA. Six days later, this was followed by high-depth RNA-seq. The rates of A-to-I conversion were similar in edited and unedited control cells, which is consistent with previous reports that off-target RNA editing was not detected after high-level adenine base editing of HUDEP2 cells or HSPCs.
2023-04-28 | GSE228821 | GEO
Project description:Base editing analysis of muscles from adenine base editor-treated DMD mice.
| PRJNA1105327 | ENA
Project description:ABE-Ultramax for high-efficiency biallelic adenine base editing
| PRJNA1118438 | ENA
Project description:ABE-Ultramax for high-efficiency biallelic adenine base editing
| PRJNA1118794 | ENA
Project description:Therapeutic adenine base editing of human hematopoietic stem cells