scholarly journals Efficient Correction of a Hypertrophic Cardiomyopathy Mutation by ABEmax-NG

Author(s):  
Shuhong Ma ◽  
Wenjian Jiang ◽  
Xujie Liu ◽  
Wen-Jing Lu ◽  
Tao Qi ◽  
...  

Rationale: Genetic editing has shown great potential for the treatment of human hereditary disorders via the elimination of mutations in embryos. However, the efficiency and safety of germline gene editing are not well understood. Objective: We aimed to examine the preclinical efficacy/safety of embryonic base editing in a mouse model of hypertrophic cardiomyopathy (HCM) using a novel adenine base editor (ABE) platform. Methods and Results: Here, we described the use of an ABEmax-NG to directly correct the pathogenic R404Q/+ mutation (Myh6 c.1211C>T) in embryos for a mouse model of HCM, increasing the number of wild-type embryos for in vitro fertilization. Delivery of the ABEmax-NG mRNA to embryos from R404Q/+ HCM mice resulted in 62.5-70.8% correction of the Myh6 c.1211C>T, reducing the level of mutant RNA and eliminating HCM in the post-natal mice as well as their offspring. In addition, the same sgRNA was also used to target an intronic locus (TGG PAM) with an overall editing rate of 86.7%, thus confirming that ABEmax-NG can efficiently edit target loci with different PAMs (NG) and genomic distribution in vivo. Compared with CRISPR/ssODN-mediated correction, ABEmax-NG displayed a much higher correction rate without introducing indels. DNA and RNA off-target analysis did not detect off-target editing in treated embryos and founder mice. In utero injection of adeno-associated virus 9 (AAV9) encoding the ABEmax-NG also resulted in around 25.3% correction of the pathogenic mutation and reduced of mutant RNA, thereby indicating ABEmax-NG has the potential to correct the HCM mutation in vivo. Conclusions: We developed an ABEmax-NG system, which efficiently corrected a pathogenic Myh6 HCM mutation in mouse embryos without off target lesions, thus safely eliminating HCM in derived mice and their progeny.

2021 ◽  
Vol 22 (9) ◽  
pp. 4368
Author(s):  
Heriberto Rodriguez-Martinez ◽  
Emilio A. Martinez ◽  
Juan J. Calvete ◽  
Fernando J. Peña Vega ◽  
Jordi Roca

Seminal plasma (SP), the non-cellular component of semen, is a heterogeneous composite fluid built by secretions of the testis, the epididymis and the accessory sexual glands. Its composition, despite species-specific anatomical peculiarities, consistently contains inorganic ions, specific hormones, proteins and peptides, including cytokines and enzymes, cholesterol, DNA and RNA—the latter often protected within epididymis- or prostate-derived extracellular vesicles. It is beyond question that the SP participates in diverse aspects of sperm function pre-fertilization events. The SP also interacts with the various compartments of the tubular genital tract, triggering changes in gene function that prepares for an eventual successful pregnancy; thus, it ultimately modulates fertility. Despite these concepts, it is imperative to remember that SP-free spermatozoa (epididymal or washed ejaculated) are still fertile, so this review shall focus on the differences between the in vivo roles of the SP following semen deposition in the female and those regarding additions of SP on spermatozoa handled for artificial reproduction, including cryopreservation, from artificial insemination to in vitro fertilization. This review attempts, including our own results on model animal species, to critically summarize the current knowledge of the reproductive roles played by SP components, particularly in our own species, which is increasingly affected by infertility. The ultimate goal is to reconcile the delicate balance between the SP molecular concentration and their concerted effects after temporal exposure in vivo. We aim to appraise the functions of the SP components, their relevance as diagnostic biomarkers and their value as eventual additives to refine reproductive strategies, including biotechnologies, in livestock models and humans.


Leukemia ◽  
2021 ◽  
Author(s):  
Christos Georgiadis ◽  
Jane Rasaiyaah ◽  
Soragia Athina Gkazi ◽  
Roland Preece ◽  
Aniekan Etuk ◽  
...  

AbstractTargeting T cell malignancies using chimeric antigen receptor (CAR) T cells is hindered by ‘T v T’ fratricide against shared antigens such as CD3 and CD7. Base editing offers the possibility of seamless disruption of gene expression of problematic antigens through creation of stop codons or elimination of splice sites. We describe the generation of fratricide-resistant T cells by orderly removal of TCR/CD3 and CD7 ahead of lentiviral-mediated expression of CARs specific for CD3 or CD7. Molecular interrogation of base-edited cells confirmed elimination of chromosomal translocations detected in conventional Cas9 treated cells. Interestingly, 3CAR/7CAR co-culture resulted in ‘self-enrichment’ yielding populations 99.6% TCR−/CD3−/CD7−. 3CAR or 7CAR cells were able to exert specific cytotoxicity against leukaemia lines with defined CD3 and/or CD7 expression as well as primary T-ALL cells. Co-cultured 3CAR/7CAR cells exhibited highest cytotoxicity against CD3 + CD7 + T-ALL targets in vitro and an in vivo human:murine chimeric model. While APOBEC editors can reportedly exhibit guide-independent deamination of both DNA and RNA, we found no problematic ‘off-target’ activity or promiscuous base conversion affecting CAR antigen-specific binding regions, which may otherwise redirect T cell specificity. Combinational infusion of fratricide-resistant anti-T CAR T cells may enable enhanced molecular remission ahead of allo-HSCT for T cell malignancies.


2020 ◽  
Vol 61 (12) ◽  
pp. 1764-1775
Author(s):  
Jiayan Guo ◽  
Hanbing Mei ◽  
Zhen Sheng ◽  
Qingyuan Meng ◽  
Murielle M. Véniant ◽  
...  

Of the known regulators of atherosclerosis, miRNAs have been demonstrated to play critical roles in lipoprotein homeostasis and plaque formation. Here, we generated a novel animal model of atherosclerosis by knocking in LDLRW483X in C57BL/6 mice, as the W483X mutation in LDLR is considered the most common newly identified pathogenic mutation in Chinese familial hypercholesterolemia (FH) individuals. Using the new in vivo mouse model combined with a well-established atherosclerotic in vitro human cell model, we identified a novel atherosclerosis-related miRNA, miR-23a-3p, by microarray analysis of mouse aortic tissue specimens and human aortic endothelial cells (HAECs). miR-23a-3p was consistently downregulated in both models, which was confirmed by qPCR. Bioinformatics analysis and further validation experiments revealed that the TNFα-induced protein 3 (TNFAIP3) gene was the key target of miR-23a-3p. The miR-23a-3p-related functional pathways were then analyzed in HAECs. Collectively, the present results suggest that miR-23a-3p regulates inflammatory and apoptotic pathways in atherogenesis by targeting TNFAIP3 through the NF-κB and p38/MAPK signaling pathways.


2020 ◽  
Author(s):  
Xiaobo Zhang ◽  
Jun Xie ◽  
Hongmei Sun ◽  
Qing Wei ◽  
Ying Tao ◽  
...  

Abstract Background Neutrophilic asthma (NA) was a subtype of asthma. Soluble advanced glycosylation receptor (sRAGE) was considered to be associated with the neutrophilic airway. However, the role of sRAGE in NA still limited. Methods A NA mouse model was established and the levels of sRAGE in the bronchoalveolar lavage fluid (BALF) were measured by ELISA. Hematoxylin-eosin (HE) and Masson trichrome staining were used to identifying airway remodeling. Adeno-associated virus 9 (AAV9) overexpressed sRAGE and inhibitors for HMGB1, RAGE, and PI3K were used to intervene NA mouse model via tail-vein injection and intraperitoneally injection. Expressions of airway remodeling, EMT, and signaling markers were detected using qRT-PCR or western blotting. The levels of IL-17 and IL-6 in BALF were measured by ELISA. HMGB1 was applied to induce EMT of human bronchial epithelial cells (16HBE), then E-cadherin and vimentin expressions were examined after sRAGE, RAGE inhibitor, and PI3K inhibitor administration. Results sRAGE levels were significantly reduced in BALF and the airway remodeling was observed in the NA mouse model. AAV9-sRAGE significantly inhibited the neutrophilic airway inflammation, airway remodeling, and the expression of IL-17, IL-6, TGF-β1, RAGE, PI3K, and EMT markers -E-cadherin and vimentin in vivo. HMGB1 inhibitor, RAGE inhibitor, and PI3K inhibitor upregulated E-cadherin level. Moreover, HMGB1 promoted the EMT process via RAGE/PI3K in 16HBE cells and sRAGE reversed HMGB1- induced EMT in vitro. Conclusion sRAGE levels decrease in the mouse model with NA. sRAGE treatment attenuates neutrophilic airway inflammation, airway remodeling, and EMT. This suggests sRAGE may yield benefits in the treatment of NA.


2007 ◽  
Vol 81 (14) ◽  
pp. 7540-7547 ◽  
Author(s):  
Chengwen Li ◽  
Matthew Hirsch ◽  
Aravind Asokan ◽  
Brian Zeithaml ◽  
Hong Ma ◽  
...  

ABSTRACT A recent clinical trial has suggested that recombinant adeno-associated virus (rAAV) vector transduction in humans induces a cytotoxic T-lymphocyte (CTL) response against the AAV2 capsid. To directly address the ability of AAV capsid-specific CTLs to eliminate rAAV-transduced cells in vitro and in vivo in mice, we first demonstrated that AAV2 capsid-specific CTLs could be induced by dendritic cells with endogenous AAV2 capsid expression or pulsed with AAV2 vectors. These CTLs were able to kill a cell line stable for capsid expression in vitro and also in a mouse tumor xenograft model in vivo. Parent colon carcinoma (CT26) cells transduced with a large amount of AAV2 vectors in vitro were also destroyed by these CTLs. To determine the effect of CTLs on the elimination of target cells transduced by AAV2 vectors in vivo, we carried out adoptive transfer experiments. CTLs eliminated liver cells with endogenous AAV2 capsid expression but not liver cells transduced by AAV2 vectors, regardless of the reporter genes. Similar results were obtained for rAAV2 transduction in muscle. Our data strongly suggest that AAV vector-transduced cells are rarely eliminated by AAV2 capsid-specific CTLs in vivo, even though the AAV capsid can induce a CTL response. In conclusion, AAV capsid-specific CTLs do not appear to play a role in elimination of rAAV-transduced cells in a mouse model. In addition, our data suggest that the mouse model may not mimic the immune response noted in humans and additional modification to AAV vectors may be required for further study in order to elicit a similar cellular immune response.


2020 ◽  
Author(s):  
John R Sinnamon ◽  
Susan Y Kim ◽  
Jenna R Fisk ◽  
Zhen Song ◽  
Hiroyuki Nakai ◽  
...  

AbstractRNA base editing is gaining momentum as an approach to repair mutations, but its application to neurological disease has not been established. We have succeeded in directed transcript editing of a pathological mutation in a mouse model of the neurodevelopmental disease, Rett syndrome. Specifically, we directed editing of a guanosine to adenosine mutation in RNA encoding Methyl CpG Binding Protein 2 (MECP2). Repair was mediated by injecting the hippocampus of juvenile Rett mice with an adeno-associated virus expressing both an engineered enzyme containing the catalytic domain of Adenosine Deaminase Acting on RNA 2 and a Mecp2 targeting guide. After one month, 50% of Mecp2 RNA was recoded in three different hippocampal neuronal subtypes, and the ability of MeCP2 protein to associate with heterochromatin was similarly restored to 50% of wild-type levels. This study represents the first in vivo programmable RNA editing applied to a model of neurological disease.


Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1288
Author(s):  
Wendy Dong ◽  
Boris Kantor

CRISPR/Cas technology has revolutionized the fields of the genome- and epigenome-editing by supplying unparalleled control over genomic sequences and expression. Lentiviral vector (LV) systems are one of the main delivery vehicles for the CRISPR/Cas systems due to (i) its ability to carry bulky and complex transgenes and (ii) sustain robust and long-term expression in a broad range of dividing and non-dividing cells in vitro and in vivo. It is thus reasonable that substantial effort has been allocated towards the development of the improved and optimized LV systems for effective and accurate gene-to-cell transfer of CRISPR/Cas tools. The main effort on that end has been put towards the improvement and optimization of the vector’s expression, development of integrase-deficient lentiviral vector (IDLV), aiming to minimize the risk of oncogenicity, toxicity, and pathogenicity, and enhancing manufacturing protocols for clinical applications required large-scale production. In this review, we will devote attention to (i) the basic biology of lentiviruses, and (ii) recent advances in the development of safer and more efficient CRISPR/Cas vector systems towards their use in preclinical and clinical applications. In addition, we will discuss in detail the recent progress in the repurposing of CRISPR/Cas systems related to base-editing and prime-editing applications.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xuejie Gao ◽  
Bo Li ◽  
Anqi Ye ◽  
Houcai Wang ◽  
Yongsheng Xie ◽  
...  

Abstract Background Multiple myeloma (MM) is a highly aggressive and incurable clonal plasma cell disease with a high rate of recurrence. Thus, the development of new therapies is urgently needed. DCZ0805, a novel compound synthesized from osalmide and pterostilbene, has few observed side effects. In the current study, we intend to investigate the therapeutic effects of DCZ0805 in MM cells and elucidate the molecular mechanism underlying its anti-myeloma activity. Methods We used the Cell Counting Kit-8 assay, immunofluorescence staining, cell cycle assessment, apoptosis assay, western blot analysis, dual-luciferase reporter assay and a tumor xenograft mouse model to investigate the effect of DCZ0805 treatment both in vivo and in vitro. Results The results showed that DCZ0805 treatment arrested the cell at the G0/G1 phase and suppressed MM cells survival by inducing apoptosis via extrinsic and intrinsic pathways. DCZ0805 suppressed the NF-κB signaling pathway activation, which may have contributed to the inhibition of cell proliferation. DCZ0805 treatment remarkably reduced the tumor burden in the immunocompromised xenograft mouse model, with no obvious toxicity observed. Conclusion The findings of this study indicate that DCZ0805 can serve as a novel therapeutic agent for the treatment of MM.


2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii413-iii413
Author(s):  
Maggie Seblani ◽  
Markella Zannikou ◽  
Katarzyna Pituch ◽  
Liliana Ilut ◽  
Oren Becher ◽  
...  

Abstract Diffuse intrinsic pontine glioma (DIPG) is a devastating brain tumor affecting young children. Immunotherapies hold promise however the lack of immunocompetent models recreating a faithful tumor microenvironment (TME) remains a challenge for development of targeted immunotherapeutics. We propose to generate an immunocompetent DIPG mouse model through induced overexpression of interleukin 13 receptor alpha 2 (IL13Rα2), a tumor-associated antigen overexpressed by glioma cells. A model with an intact TME permits comprehensive preclinical assessment of IL13Rα2-targeted immunotherapeutics. Our novel model uses the retroviral avian leucosis and sarcoma virus (RCAS) for in vivo gene delivery leading to IL13Rα2 expression in proliferating progenitor cells. Transfected cells expressing IL13Rα2 and PDGFB, a ligand for platelet derived growth factor receptor, alongside induced p53 loss via the Cre-Lox system are injected in the fourth ventricle in postnatal pups. We validated the expression of PDGFB and IL13Rα2 transgenes in vitro and in vivo and will characterize the TME through evaluation of the peripheral and tumor immunologic compartments using immunohistochemistry and flow cytometry. We confirmed expression of transgenes via flow cytometry and western blotting. Comparison of survival dynamics in mice inoculated with PDGFB alone with PDGFB+IL13Rα2 demonstrated that co-expression of IL13Rα2 did not significantly affect mice survival compared to the PDGFB model. At time of application, we initiated experiments to characterize the TME. Preliminary data demonstrate establishment of tumors within and adjacent to the brainstem and expression of target transgenes. Preclinical findings in a model recapitulating the TME may provide better insight into outcomes upon translation to clinical application.


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