Project description:CRISPR-based gene editing holds promise for treating genetic diseases, yet its application to lung disorders has been hindered by the challenges of pulmonary delivery. Inspired by the modularity and biocompatibility of amino acid-derived chemistries, we report the combinatorial synthesis of 960 ionizable lipids incorporating chemically diverse backbones from both proteinogenic and non-proteinogenic α-amino acids. Through high-throughput screening and structure-function analysis, we identify CHCha-10, a cyclohexyl amino acid-derived lipid that forms biodegradable nanoparticles capable of efficiently delivering mRNA-based gene editors to lung epithelial cells. Following intratracheal administration, CHCha-10 nanoparticles exhibit enhanced mucus penetration, and epithelial-specific transfection in both mice and ferrets. As a functional application, we demonstrate the first instance of in vivo base editing in the lung via inhalation. Delivery of adenine base editor mRNA and guide RNA targeting the CFTR G542X mutation restores CFTR expression and chloride channel function in G542X human airway epithelial cells, mouse-derived intestinal organoids, and the lungs of cystic fibrosis mice.
Project description:We then deliver the ‘RESTART v3’ system, which is a CRISPR-free RNA base editor for nonsense mutation suppression, into the cochlea of the mice. We achieve physiological otoferlin expression, the edited premature termination codon is reverse-mutated to the original amino acid. We observe significant hearing restoration and enhancement of the behavioral auditory startle reflex.
Project description:Hutchinson-Gilford Progeria Syndrome (HGPS) is a premature aging disorder affecting tissues of mesenchymal origin. Most patients harbor a c.1824C>T/p.G608= variant, commonly described as G608G, in exon 11 of LMNA that leads to aberrant splicing and production of the toxic progerin protein. In addition to cardiovascular, dermal, and adipose tissue deterioration, HGPS mouse models also develop progressive bone dysplasia that occurs in patients. Here we characterize the efficacy of in vivo mutation correction with an adenine base editor (ABE) to rescue structural and functional defects in HGPS transgenic murine bone tissue. Treatment of double-copy transgenic osteoblast cultures with a lentiviral-delivered CRISPR-Cas9 ABE achieved nearly 40% gene correction in vitro, resulting in significant reduction of progerin transcripts and protein, in the absence of selective agents. Furthermore, gene correction improved progeroid osteoblasts’ capacity to deposit and mineralize extracellular matrix compared to untreated cultures. In vivo, a single intravenous dose of AAV9-delivered ABE corrected the mutation, achieving ~14%, ~22%, ~10% and <1% correction in bone by six months of age when administered at P3, P14, 1 and 4 months of age, respectively. Partially rescued bone structural and physical parameters were observed in P14-treated mice with concomitant normalization of gene transcriptional programs and intracellular signaling pathways involved in bone remodeling. This work demonstrates in vivo delivery of a locus-specific DNA base editor to bone tissue, delineates the timing of treatment required for maximum efficacy, and suggests that this system might be tailored for application to other monogenic bone disorders.
Project description:We evaluate CRISPR-based prime editing for application in organoids. First we model mutations in TP53 in intestinal and hepatocyte oganoids and determine the efficiency and accuracy of mutation induction on multiple targets. Then, to evaluate potential clinical applicability of prime editing we repair mutations in the CFTR channel that cause cystic fibrosis in intestinal organoids. First we repair the CFTR-F508del mutation which is the most common mutation in cystic fibrosis. Then we compare adenine base editing to prime editing by repairing the CFTR-R785* mutation using both strategies.
Project description:We used an adenine base editor to target the translation start site and mRNA splicing site of Camk2d in order to knock out CaMKIIδ. We found that editing the 5' splice site of intron 7 can lead to premature translation termination, effectively knocking out CaMKIIδ.
Project description:We used an adenine base editor to target the translation start site and mRNA splicing site of Camk2d in order to knock out CaMKIIδ. We found that editing the 5' splice site of intron 7 can lead to premature translation termination, effectively knocking out CaMKIIδ.
Project description:Current base editors use DNA deaminases, including cytidine deaminase in cytidine base editor (CBE) or adenine deaminase in adenine base editor (ABE), to facilitate transition nucleotide substitutions. Combining CBE or ABE with glycosylase enzymes can induce limited transversion mutations. Nonetheless, a critical demand remains for base editors capable of generating alternative mutation types, such as T>G corrections. In this study, we leveraged pre-trained protein language models to optimize a uracil-N-glycosylase (UNG) variant with altered specificity for thymines (eTDG). Notably, after two rounds of testing fewer than 50 top-ranking variants, more than 50% exhibited over 1.5-fold enhancement in enzymatic activities. When eTDG was fused with nCas9, it induced programmable T-to-S (G/C) substitutions and corrected db/db diabetic mutation in mice (up to 55%). Our findings not only establish orthogonal strategies for developing novel base editors, but also demonstrate the capacities of protein language models for optimizing enzymes without extensive task-specific training data.
Project description:Delivery strategies for gene editing applications can affect editing outcomes by eliciting distinct cellular responses. This work presents bulk RNA sequencing data from human bronchial epithelial CFF-16HBEge cells, following delivery of an adenine base editor and sgRNA as plasmid DNA via lipofection or as ribonucleoprotein complexes via engineered virus-like particles (eVLPs). Differential gene expression and gene ontology analyses revealed condition-specific transcriptional profiles. This dataset provides a resource for investigating cellular responses to gene editing delivery approaches in vitro.
Project description:Restrictive cardiomyopathy (RCM) is a severe cardiac disorder characterized by impaired ventricular filling and diastolic dysfunction, with mutations in sarcomeric proteins representing major causative factors. Mutations of TNNI3 gene (e.g. p.R192H) constitute major genetic causes of RCM, particularly affecting pediatric patients and being associated with poor prognosis. Here, we demonstrate that adenine base editor (ABE) is able effectively correct RCM-causing mutation and alleviate RCM in a murine model. We first developed a novel murine model harboring the Tnni3R193H mutation that recapitulates the hallmark features of human RCM. Importantly, targeted delivery of ABE via adeno-associated virus (AAV) achieved efficient and precise correction of the Tnni3R193H mutation in adult RCM mice, leading to significant improvement of cardiac functions. Our findings establish base editing as a therapeutic strategy for RCM and highlight its broader potential for treating genetic cardiomyopathies in clinical settings.