scholarly journals A Newly Built rAAV-SaCas9 Genome Editing System Enables Muscle-Directed Gene Editing to Improve Muscular Atrophy

2020 ◽  
Author(s):  
Shaoting Weng ◽  
Xingyu Li ◽  
Yitian Zhao ◽  
Feng Gao ◽  
Mengmeng Shi ◽  
...  

Abstract Background At present, genome editing at specific sites in vivo is affected by many factors, including the choice of vector, the efficiency of editing proteins and the influence of the internal environment. These factors make gene editing ineffective and even have adverse effects. Methods Here, we report a single rAAV containing SaCas9 and guide RNAs under the control of subtle EF1a and tRNA promoters. The capacity of rAAV was compressed, and we inserted the sequence of the green fluorescent protein eGFP into rAAV. The efficiency of rAAV gene editing in vivo and in vitro was analyzed by time point and virus titer. In addition, we used the rAAV9-SaCas9 system to knock out the myostatin gene in the thigh muscles of muscle-atrophic mice. Results We demonstrated that the gene editing elements regulated by the rAAV-SaCas9 system can be expressed. By increasing the amount of rAAV and the reaction time, the editing efficiency of myostatin and the expression level of eGFP protein can be improved in vitro and vivo. Furthermore, We demonstrated that muscle cells were improved by knockout partial myostatin gene in a mouse model of muscular dystrophy. Conclusions The rAAV-SaCas9 system can be expressed in a stable and long-term manner. The system has substantial therapeutic potential in treating muscular atrophy.

Author(s):  
Shaoting Weng ◽  
Yitian Zhao ◽  
Changhong Yu ◽  
Xiaofan Wang ◽  
Xuehan Xiao ◽  
...  

AbstractAn ideal rAAV gene editing system not only effectively edits genes at specific site, but also prevents the spread of the virus from occurring off-target or carcinogenic risks. This is important for gene editing research at specific site in vivo. We report a single rAAV containing SaCas9 and guide RNAs under the control of subtle EF1a and tRNA promoters. The capacity of rAAV was compressed, and the editing efficiency was similar to that of the classical Cas9 system in vitro and in vivo. And we inserted the sequence of the green fluorescent protein eGFP into rAAV. The number of cells infected with the rAAV and the region in which the rAAV spreads were known by the fluorescent expression of eGFP in cells. In addition, we demonstrated that myostatin gene in the thigh muscles of C57BL/10 mice was knocked out by the rAAV9-SaCas9 system to make muscle mass increased obviously. The protein eGFP into rAAV has significant implications for our indirect analysis of the editing efficiency of SaCas9 in the genome of the target tissue and reduces the harm caused by off-target editing and prevents other tissue mutations. The rAAV system has substantial potential in improving muscle mass and preventing muscle atrophy.


2022 ◽  
Vol 23 (2) ◽  
pp. 837
Author(s):  
Sudip Biswas ◽  
Nancy J. Wahl ◽  
Michael J. Thomson ◽  
John M. Cason ◽  
Bill F. McCutchen ◽  
...  

The cultivated peanut (Arachis hypogaea L.) is a legume consumed worldwide in the form of oil, nuts, peanut butter, and candy. Improving peanut production and nutrition will require new technologies to enable novel trait development. Clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9 (CRISPR–Cas9) is a powerful and versatile genome-editing tool for introducing genetic changes for studying gene expression and improving crops, including peanuts. An efficient in vivo transient CRISPR–Cas9- editing system using protoplasts as a testbed could be a versatile platform to optimize this technology. In this study, multiplex CRISPR–Cas9 genome editing was performed in peanut protoplasts to disrupt a major allergen gene with the help of an endogenous tRNA-processing system. In this process, we successfully optimized protoplast isolation and transformation with green fluorescent protein (GFP) plasmid, designed two sgRNAs for an allergen gene, Ara h 2, and tested their efficiency by in vitro digestion with Cas9. Finally, through deep-sequencing analysis, several edits were identified in our target gene after PEG-mediated transformation in protoplasts with a Cas9 and sgRNA-containing vector. These findings demonstrated that a polyethylene glycol (PEG)-mediated protoplast transformation system can serve as a rapid and effective tool for transient expression assays and sgRNA validation in peanut.


2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Guzide Bender ◽  
Rezan Fahrioglu Yamaci ◽  
Bahar Taneri

AbstractCRISPR (clustered regularly interspaced short palindromic repeats) systems are one of the most fascinating tools of the current era in molecular biotechnology. With the ease that they provide in genome editing, CRISPR systems generate broad opportunities for targeting mutations. Specifically in recent years, disease-causing mutations targeted by the CRISPR systems have been of main research interest; particularly for those diseases where there is no current cure, including cancer. KRAS mutations remain untargetable in cancer. Mutations in this oncogene are main drivers in common cancers, including lung, colorectal and pancreatic cancers, which are severe causes of public health burden and mortality worldwide, with no cure at hand. CRISPR systems provide an opportunity for targeting cancer causing mutations. In this review, we highlight the work published on CRISPR applications targeting KRAS mutations directly, as well as CRISPR applications targeting mutations in KRAS-related molecules. In specific, we focus on lung, colorectal and pancreatic cancers. To date, the limited literature on CRISPR applications targeting KRAS, reflect promising results. Namely, direct targeting of mutant KRAS variants using various CRISPR systems resulted in significant decrease in cell viability and proliferation in vitro, as well as tumor growth inhibition in vivo. In addition, the effect of mutant KRAS knockdown, via CRISPR, has been observed to exert regulatory effects on the downstream molecules including PI3K, ERK, Akt, Stat3, and c-myc. Molecules in the KRAS pathway have been subjected to CRISPR applications more often than KRAS itself. The aim of using CRISPR systems in these studies was mainly to analyze the therapeutic potential of possible downstream and upstream effectors of KRAS, as well as to discover further potential molecules. Although there have been molecules identified to have such potential in treatment of KRAS-driven cancers, a substantial amount of effort is still needed to establish treatment strategies based on these discoveries. We conclude that, at this point in time, despite being such a powerful directed genome editing tool, CRISPR remains to be underutilized for targeting KRAS mutations in cancer. Efforts channelled in this direction, might pave the way in solving the long-standing challenge of targeting the KRAS mutations in cancers.


2018 ◽  
Vol 115 (19) ◽  
pp. 4903-4908 ◽  
Author(s):  
Hong-Xia Wang ◽  
Ziyuan Song ◽  
Yeh-Hsing Lao ◽  
Xin Xu ◽  
Jing Gong ◽  
...  

Effective and safe delivery of the CRISPR/Cas9 gene-editing elements remains a challenge. Here we report the development of PEGylated nanoparticles (named P-HNPs) based on the cationic α-helical polypeptide poly(γ-4-((2-(piperidin-1-yl)ethyl)aminomethyl)benzyl-l-glutamate) for the delivery of Cas9 expression plasmid and sgRNA to various cell types and gene-editing scenarios. The cell-penetrating α-helical polypeptide enhanced cellular uptake and promoted escape of pCas9 and/or sgRNA from the endosome and transport into the nucleus. The colloidally stable P-HNPs achieved a Cas9 transfection efficiency up to 60% and sgRNA uptake efficiency of 67.4%, representing an improvement over existing polycation-based gene delivery systems. After performing single or multiplex gene editing with an efficiency up to 47.3% in vitro, we demonstrated that P-HNPs delivering Cas9 plasmid/sgRNA targeting the polo-like kinase 1 (Plk1) gene achieved 35% gene deletion in HeLa tumor tissue to reduce the Plk1 protein level by 66.7%, thereby suppressing the tumor growth by >71% and prolonging the animal survival rate to 60% within 60 days. Capable of delivering Cas9 plasmids to various cell types to achieve multiplex gene knock-out, gene knock-in, and gene activation in vitro and in vivo, the P-HNP system offers a versatile gene-editing platform for biological research and therapeutic applications.


2019 ◽  
Vol 19 (3) ◽  
pp. 164-174 ◽  
Author(s):  
Jinyu Sun ◽  
Jianchu Wang ◽  
Donghui Zheng ◽  
Xiaorong Hu

Abstract Clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (Cas9) is one of the most versatile and efficient gene editing technologies, which is derived from adaptive immune strategies for bacteria and archaea. With the remarkable development of programmable nuclease-based genome engineering these years, CRISPR-Cas9 system has developed quickly in recent 5 years and has been widely applied in countless areas, including genome editing, gene function investigation and gene therapy both in vitro and in vivo. In this paper, we briefly introduce the mechanisms of CRISPR-Cas9 tool in genome editing. More importantly, we review the recent therapeutic application of CRISPR-Cas9 in various diseases, including hematologic diseases, infectious diseases and malignant tumor. Finally, we discuss the current challenges and consider thoughtfully what advances are required in order to further develop the therapeutic application of CRISPR-Cas9 in the future.


2020 ◽  
Vol 27 (12) ◽  
pp. 960-975
Author(s):  
Shaoting Weng ◽  
Feng Gao ◽  
Juan Wang ◽  
Xingyu Li ◽  
Beibei Chu ◽  
...  

AbstractMuscle mass and area usually decrease with age, and this phenomenon is known as sarcopenia. This age-related atrophy correlates with insufficient levels of muscle cells differentiate and proliferate regulated by the TGF-β signaling pathway and the expression of E3s ubiquitin-protein ligase by the aged. Sarcopenia makes a huge impact on the aging society, because it has the characteristic of high incidence, extensive adverse effects and disease aggravation gradually. Guided by a single-guide RNA (sgRNA), Cas9 nuclease has been widely used in genome editing, opening up a new pathway for sarcopenia treatment. Here, we present two rAAV9 systems, pX601-AAV-CMV:SaCas9-U6:sgRNA and pX601-AAV-EF1α:SaCas9-tRNAGLN: sgRNA, which edited myostatin efficiently. By delivering the two rAAV–SaCas9 targets to myostatin via intramuscular injection of aged mice, an increase in body weight and an increase in the number and area of myofibers were observed. Knockout of myostatin led to TGF-β signaling pathway changes, and increased MyoD, Pax7 and MyoG protein levels and increased the number of satellite cells to improve muscle cells differentiation. Moreover, knockout of myostatin prevented the atrophy of muscle cells through reduced Murf1 and MAFbx protein levels. We found that both rAAV–SaCas9 systems had gene editing efficiency, reducing the expression of myostatin by affecting the relevant signaling pathways, thereby altering the physiological status. We showed that myostatin has an important role in activating skeletal muscle proliferation and inhibiting muscular atrophy during aging. Thus, we propose that knockout of myostatin using the rAAV9–SaCas9 system has significant therapeutic potential in sarcopenia.


2019 ◽  
Vol 116 (5) ◽  
pp. 894-907 ◽  
Author(s):  
Eva Vermersch ◽  
Charlène Jouve ◽  
Jean-Sébastien Hulot

Abstract Cardiovascular diseases are among the main causes of morbidity and mortality in Western countries and considered as a leading public health issue. Therefore, there is a strong need for new disease models to support the development of novel therapeutics approaches. The successive improvement of genome editing tools with zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and more recently with clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9) has enabled the generation of genetically modified cells and organisms with much greater efficiency and precision than before. The simplicity of CRISPR/Cas9 technology made it especially suited for different studies, both in vitro and in vivo, and has been used in multiple studies evaluating gene functions, disease modelling, transcriptional regulation, and testing of novel therapeutic approaches. Notably, with the parallel development of human induced pluripotent stem cells (hiPSCs), the generation of knock-out and knock-in human cell lines significantly increased our understanding of mutation impacts and physiopathological mechanisms within the cardiovascular domain. Here, we review the recent development of CRISPR–Cas9 genome editing, the alternative tools, the available strategies to conduct genome editing in cardiovascular cells with a focus on its use for correcting mutations in vitro and in vivo both in germ and somatic cells. We will also highlight that, despite its potential, CRISPR/Cas9 technology comes with important technical and ethical limitations. The development of CRISPR/Cas9 genome editing for cardiovascular diseases indeed requires to develop a specific strategy in order to optimize the design of the genome editing tools, the manipulation of DNA repair mechanisms, the packaging and delivery of the tools to the studied organism, and the assessment of their efficiency and safety.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Benedetta M. Motta ◽  
Peter P. Pramstaller ◽  
Andrew A. Hicks ◽  
Alessandra Rossini

Genome-editing technology has emerged as a powerful method that enables the generation of genetically modified cells and organisms necessary to elucidate gene function and mechanisms of human diseases. The clustered regularly interspaced short palindromic repeats- (CRISPR-) associated 9 (Cas9) system has rapidly become one of the most popular approaches for genome editing in basic biomedical research over recent years because of its simplicity and adaptability. CRISPR/Cas9 genome editing has been used to correct DNA mutations ranging from a single base pair to large deletions in both in vitro and in vivo model systems. CRISPR/Cas9 has been used to increase the understanding of many aspects of cardiovascular disorders, including lipid metabolism, electrophysiology and genetic inheritance. The CRISPR/Cas9 technology has been proven to be effective in creating gene knockout (KO) or knockin in human cells and is particularly useful for editing induced pluripotent stem cells (iPSCs). Despite these progresses, some biological, technical, and ethical issues are limiting the therapeutic potential of genome editing in cardiovascular diseases. This review will focus on various applications of CRISPR/Cas9 genome editing in the cardiovascular field, for both disease research and the prospect of in vivo genome-editing therapies in the future.


Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2504
Author(s):  
Anna Koslová ◽  
Pavel Trefil ◽  
Jitka Mucksová ◽  
Veronika Krchlíková ◽  
Jiří Plachý ◽  
...  

The chicken Tva cell surface protein, a member of the low-density lipoprotein receptor family, has been identified as an entry receptor for avian leukosis virus of classic subgroup A and newly emerging subgroup K. Because both viruses represent an important concern for the poultry industry, we introduced a frame-shifting deletion into the chicken tva locus with the aim of knocking-out Tva expression and creating a virus-resistant chicken line. The tva knock-out was prepared by CRISPR/Cas9 gene editing in chicken primordial germ cells and orthotopic transplantation of edited cells into the testes of sterilized recipient roosters. The resulting tva −/− chickens tested fully resistant to avian leukosis virus subgroups A and K, both in in vitro and in vivo assays, in contrast to their susceptible tva +/+ and tva +/− siblings. We also found a specific disorder of the cobalamin/vitamin B12 metabolism in the tva knock-out chickens, which is in accordance with the recently recognized physiological function of Tva as a receptor for cobalamin in complex with transcobalamin transporter. Last but not least, we bring a new example of the de novo resistance created by CRISPR/Cas9 editing of pathogen dependence genes in farm animals and, furthermore, a new example of gene editing in chicken.


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