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Mattar CN, Chew WL, Lai PS. Embryo and fetal gene editing: Technical challenges and progress toward clinical applications. Mol Ther Methods Clin Dev 2024; 32:101229. [PMID: 38533521 PMCID: PMC10963250 DOI: 10.1016/j.omtm.2024.101229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
Gene modification therapies (GMTs) are slowly but steadily making progress toward clinical application. As the majority of rare diseases have an identified genetic cause, and as rare diseases collectively affect 5% of the global population, it is increasingly important to devise gene correction strategies to address the root causes of the most devastating of these diseases and to provide access to these novel therapies to the most affected populations. The main barriers to providing greater access to GMTs continue to be the prohibitive cost of developing these novel drugs at clinically relevant doses, subtherapeutic effects, and toxicity related to the specific agents or high doses required. In vivo strategy and treating younger patients at an earlier course of their disease could lower these barriers. Although currently regarded as niche specialties, prenatal and preconception GMTs offer a robust solution to some of these barriers. Indeed, treating either the fetus or embryo benefits from economy of scale, targeting pre-pathological tissues in the fetus prior to full pathogenesis, or increasing the likelihood of complete tissue targeting by correcting pluripotent embryonic cells. Here, we review advances in embryo and fetal GMTs and discuss requirements for clinical application.
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Affiliation(s)
- Citra N.Z. Mattar
- Experimental Fetal Medicine Group, Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, NUHS Tower Block, Level 12, Singapore, Singapore 119228
- Department of Obstetrics and Gynaecology, National University Health System, Singapore, 1E Kent Ridge Road, NUHS Tower Block, Level 12, Singapore, Singapore 119228
| | - Wei Leong Chew
- Genome Institute of Singapore, Agency for Science, Technology and Research (A∗STAR), Singapore, 60 Biopolis St, Singapore, Singapore 138672
| | - Poh San Lai
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, NUHS Tower Block, Level 12, Singapore, Singapore 119228
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Navarro-Serna S, Piñeiro-Silva C, Fernández-Martín I, Dehesa-Etxebeste M, López de Munain A, Gadea J. Oocyte electroporation prior to in vitro fertilization is an efficient method to generate single, double, and multiple knockout porcine embryos of interest in biomedicine and animal production. Theriogenology 2024; 218:111-118. [PMID: 38320372 DOI: 10.1016/j.theriogenology.2024.01.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 01/31/2024] [Accepted: 01/31/2024] [Indexed: 02/08/2024]
Abstract
Genetically modified pigs play a critical role in mimicking human diseases, xenotransplantation, and the development of pigs resistant to viral diseases. The use of programmable endonucleases, including the CRISPR/Cas9 system, has revolutionized the generation of genetically modified pigs. This study evaluates the efficiency of electroporation of oocytes prior to fertilization in generating edited gene embryos for different models. For single gene editing, phospholipase C zeta (PLC ζ) and fused in sarcoma (FUS) genes were used, and the concentration of sgRNA and Cas9 complexes was optimized. The results showed that increasing the concentration resulted in higher mutation rates without affecting the blastocyst rate. Electroporation produced double knockouts for the TPC1/TPC2 genes with high efficiency (79 %). In addition, resistance to viral diseases such as PRRS and swine influenza was achieved by electroporation, allowing the generation of double knockout embryo pigs (63 %). The study also demonstrated the potential for multiple gene editing in a single step using electroporation, which is relevant for xenotransplantation. The technique resulted in the simultaneous mutation of 5 genes (GGTA1, B4GALNT2, pseudo B4GALNT2, CMAH and GHR). Overall, electroporation proved to be an efficient and versatile method to generate genetically modified embryonic pigs, offering significant advances in biomedical and agricultural research, xenotransplantation, and disease resistance. Electroporation led to the processing of numerous oocytes in a single session using less expensive equipment. We confirmed the generation of gene-edited porcine embryos for single, double, or quintuple genes simultaneously without altering embryo development to the blastocyst stage. The results provide valuable insights into the optimization of gene editing protocols for different models, opening new avenues for research and applications in this field.
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Affiliation(s)
- Sergio Navarro-Serna
- Department Physiology, University of Murcia, International Excellence Campus for Higher Education and Research "Campus Mare Nostrum" and Institute for Biomedical Research of Murcia (IMIB-Arrixaca), 30100, Murcia, Spain
| | - Celia Piñeiro-Silva
- Department Physiology, University of Murcia, International Excellence Campus for Higher Education and Research "Campus Mare Nostrum" and Institute for Biomedical Research of Murcia (IMIB-Arrixaca), 30100, Murcia, Spain
| | - Irene Fernández-Martín
- Department Physiology, University of Murcia, International Excellence Campus for Higher Education and Research "Campus Mare Nostrum" and Institute for Biomedical Research of Murcia (IMIB-Arrixaca), 30100, Murcia, Spain
| | | | - Adolfo López de Munain
- IIS Biodonostia, Neuroscience, San Sebastián, Spain; Department of Neurology. Hospital Universitario Donostia-OSAKIDETZA, San Sebastián, Spain; Department of Neurosciences. University of the Basque Country (UPV-EHU), San Sebastián, Spain; CIBERNED (CIBER), Institute Carlos III, Madrid, Spain
| | - Joaquín Gadea
- Department Physiology, University of Murcia, International Excellence Campus for Higher Education and Research "Campus Mare Nostrum" and Institute for Biomedical Research of Murcia (IMIB-Arrixaca), 30100, Murcia, Spain.
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Chehelgerdi M, Chehelgerdi M, Khorramian-Ghahfarokhi M, Shafieizadeh M, Mahmoudi E, Eskandari F, Rashidi M, Arshi A, Mokhtari-Farsani A. Comprehensive review of CRISPR-based gene editing: mechanisms, challenges, and applications in cancer therapy. Mol Cancer 2024; 23:9. [PMID: 38195537 PMCID: PMC10775503 DOI: 10.1186/s12943-023-01925-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 12/20/2023] [Indexed: 01/11/2024] Open
Abstract
The CRISPR system is a revolutionary genome editing tool that has the potential to revolutionize the field of cancer research and therapy. The ability to precisely target and edit specific genetic mutations that drive the growth and spread of tumors has opened up new possibilities for the development of more effective and personalized cancer treatments. In this review, we will discuss the different CRISPR-based strategies that have been proposed for cancer therapy, including inactivating genes that drive tumor growth, enhancing the immune response to cancer cells, repairing genetic mutations that cause cancer, and delivering cancer-killing molecules directly to tumor cells. We will also summarize the current state of preclinical studies and clinical trials of CRISPR-based cancer therapy, highlighting the most promising results and the challenges that still need to be overcome. Safety and delivery are also important challenges for CRISPR-based cancer therapy to become a viable clinical option. We will discuss the challenges and limitations that need to be overcome, such as off-target effects, safety, and delivery to the tumor site. Finally, we will provide an overview of the current challenges and opportunities in the field of CRISPR-based cancer therapy and discuss future directions for research and development. The CRISPR system has the potential to change the landscape of cancer research, and this review aims to provide an overview of the current state of the field and the challenges that need to be overcome to realize this potential.
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Affiliation(s)
- Mohammad Chehelgerdi
- Novin Genome (NG) Lab, Research and Development Center for Biotechnology, Shahrekord, Iran.
- Young Researchers and Elite Club, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran.
| | - Matin Chehelgerdi
- Novin Genome (NG) Lab, Research and Development Center for Biotechnology, Shahrekord, Iran
- Young Researchers and Elite Club, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran
| | - Milad Khorramian-Ghahfarokhi
- Division of Biotechnology, Department of Pathobiology, School of Veterinary Medicine, Shiraz University, Shiraz, Iran
| | | | - Esmaeil Mahmoudi
- Young Researchers and Elite Club, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran
| | - Fatemeh Eskandari
- Faculty of Molecular and Cellular Biology -Genetics, Islamic Azad University of Falavarjan, Isfahan, Iran
| | - Mohsen Rashidi
- Department Pharmacology, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
- The Health of Plant and Livestock Products Research Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - Asghar Arshi
- Young Researchers and Elite Club, Najafabad Branch, Islamic Azad University, Najafabad, Iran
| | - Abbas Mokhtari-Farsani
- Novin Genome (NG) Lab, Research and Development Center for Biotechnology, Shahrekord, Iran
- Department of Biology, Nourdanesh Institute of Higher Education, Meymeh, Isfahan, Iran
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Le QA, Wittayarat M, Namula Z, Lin Q, Takebayashi K, Hirata M, Tanihara F, Do LTK, Otoi T. Multiple gene editing in porcine embryos using a combination of microinjection, electroporation, and transfection methods. Vet World 2022; 15:2210-2216. [PMID: 36341066 PMCID: PMC9631378 DOI: 10.14202/vetworld.2022.2210-2216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 08/17/2022] [Indexed: 11/17/2022] Open
Abstract
Background and Aim: Mosaicism – the presence of both wild-type and mutant alleles – is a serious problem for zygotic gene modification through gene editing using the Clustered regularly interspaced short palindromic repeats-Cas9 (CRISPR/Cas9) system. Different delivery methods, such as microinjection (MI), electroporation (EP), and transfection (TF), can be used to transfer CRISPR/Cas9 components into porcine zygotes. This study aimed to develop a method that combines MI, EP, and TF to improve mutation efficiency mediated through the CRISPR/Cas9 system for a triple-gene knockout in pigs. Materials and Methods: The study consisted of three groups: The MI group with three simultaneously microinjected guide RNAs (gRNAs) targeting α-1,3-galactosyltransferase (GGTA1), cytidine 32 monophosphate-N-acetylneuraminic acid hydroxylase (CMAH), and β-1,4-N-acetyl-galactosaminyltransferase 2 (B4GALNT2); the MI + EP group with two gRNAs targeting GGTA1 and B4GALNT2 genes delivered into zygotes through MI, followed by EP of gRNA targeting the CMAH 1 h later; and the MI + EP + TF group with MI of gRNA targeting GGTA1 gene into zygotes, followed by EP of gRNA targeting CMAH 1 h later, and then TF of gRNA targeting the B4GALNT2 gene into zona-free zygotes after another hour. Results: The rate of blastocysts carrying mutations in one or two gene(s) was significantly higher in the MI + EP + TF group than in the MI group. However, the blastocyst formation rate of zygotes in the MI + EP + TF group was lower than that of the zygotes in the other treatment groups. Conclusion: The combination of CRISPR/Cas9 delivery methods may improve the mutation efficiency of triple-gene edited porcine blastocysts.
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Affiliation(s)
- Quynh Anh Le
- Bio-Innovation Research Center, Tokushima University, 7793233 Tokushima, Japan; Laboratory of Animal Reproduction, Faculty of Bioscience and Bioindustry, Tokushima University, 7793233 Tokushima, Japan
| | - Manita Wittayarat
- Faculty of Veterinary Science, Prince of Songkla University, 90110 Songkhla, Thailand
| | - Zhao Namula
- Bio-Innovation Research Center, Tokushima University, 7793233 Tokushima, Japan; Department of Veterinary Medicine, College of Coastal Agricultural Sciences, Guangdong Ocean University, 524088 Guangdong, China
| | - Qingyi Lin
- Bio-Innovation Research Center, Tokushima University, 7793233 Tokushima, Japan; Laboratory of Animal Reproduction, Faculty of Bioscience and Bioindustry, Tokushima University, 7793233 Tokushima, Japan
| | - Koki Takebayashi
- Bio-Innovation Research Center, Tokushima University, 7793233 Tokushima, Japan; Laboratory of Animal Reproduction, Faculty of Bioscience and Bioindustry, Tokushima University, 7793233 Tokushima, Japan
| | - Maki Hirata
- Bio-Innovation Research Center, Tokushima University, 7793233 Tokushima, Japan; Laboratory of Animal Reproduction, Faculty of Bioscience and Bioindustry, Tokushima University, 7793233 Tokushima, Japan
| | - Fuminori Tanihara
- Bio-Innovation Research Center, Tokushima University, 7793233 Tokushima, Japan
| | - Lanh Thi Kim Do
- Department of Animal Theriogenology and Surgery, Faculty of Veterinary Medicine, Vietnam National University of Agriculture, 100000 Hanoi, Vietnam
| | - Takeshige Otoi
- Bio-Innovation Research Center, Tokushima University, 7793233 Tokushima, Japan; Laboratory of Animal Reproduction, Faculty of Bioscience and Bioindustry, Tokushima University, 7793233 Tokushima, Japan
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Hirata M, Wittayarat M, Namula Z, Le QA, Lin Q, Takebayashi K, Thongkittidilok C, Mito T, Tomonari S, Tanihara F, Otoi T. Generation of mutant pigs by lipofection-mediated genome editing in embryos. Sci Rep 2021; 11:23806. [PMID: 34903813 PMCID: PMC8668999 DOI: 10.1038/s41598-021-03325-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 11/30/2021] [Indexed: 01/03/2023] Open
Abstract
The specificity and efficiency of CRISPR/Cas9 gene-editing systems are determined by several factors, including the mode of delivery, when applied to mammalian embryos. Given the limited time window for delivery, faster and more reliable methods to introduce Cas9-gRNA ribonucleoprotein complexes (RNPs) into target embryos are needed. In pigs, somatic cell nuclear transfer using gene-modified somatic cells and the direct introduction of gene editors into the cytoplasm of zygotes/embryos by microinjection or electroporation have been used to generate gene-edited embryos; however, these strategies require expensive equipment and sophisticated techniques. In this study, we developed a novel lipofection-mediated RNP transfection technique that does not require specialized equipment for the generation of gene-edited pigs and produced no detectable off-target events. In particular, we determined the concentration of lipofection reagent for efficient RNP delivery into embryos and successfully generated MSTN gene-edited pigs (with mutations in 7 of 9 piglets) after blastocyst transfer to a recipient gilt. This newly established lipofection-based technique is still in its early stages and requires improvements, particularly in terms of editing efficiency. Nonetheless, this practical method for rapid and large-scale lipofection-mediated gene editing in pigs has important agricultural and biomedical applications.
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Affiliation(s)
- Maki Hirata
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima, Japan.,Bio-Innovation Research Center, Tokushima University, Tokushima, Japan
| | - Manita Wittayarat
- Faculty of Veterinary Science, Prince of Songkla University, Songkhla, Thailand
| | - Zhao Namula
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima, Japan.,College of Coastal Agricultural Sciences, Guangdong Ocean University, Guangdong, China
| | - Quynh Anh Le
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima, Japan
| | - Qingyi Lin
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima, Japan
| | - Koki Takebayashi
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima, Japan
| | | | - Taro Mito
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima, Japan.,Bio-Innovation Research Center, Tokushima University, Tokushima, Japan
| | - Sayuri Tomonari
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima, Japan
| | - Fuminori Tanihara
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima, Japan. .,Center for Development of Advanced Medical Technology, Jichi Medical University, Tochigi, Japan.
| | - Takeshige Otoi
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima, Japan.,Bio-Innovation Research Center, Tokushima University, Tokushima, Japan
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Alberio R, Wolf E. 25th ANNIVERSARY OF CLONING BY SOMATIC-CELL NUCLEAR TRANSFER: Nuclear transfer and the development of genetically modified/gene edited livestock. Reproduction 2021; 162:F59-F68. [PMID: 34096507 PMCID: PMC8240728 DOI: 10.1530/rep-21-0078] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 05/04/2021] [Indexed: 12/11/2022]
Abstract
The birth and adult development of 'Dolly' the sheep, the first mammal produced by the transfer of a terminally differentiated cell nucleus into an egg, provided unequivocal evidence of nuclear equivalence among somatic cells. This ground-breaking experiment challenged a long-standing dogma of irreversible cellular differentiation that prevailed for over a century and enabled the development of methodologies for reversal of differentiation of somatic cells, also known as nuclear reprogramming. Thanks to this new paradigm, novel alternatives for regenerative medicine in humans, improved animal breeding in domestic animals and approaches to species conservation through reproductive methodologies have emerged. Combined with the incorporation of new tools for genetic modification, these novel techniques promise to (i) transform and accelerate our understanding of genetic diseases and the development of targeted therapies through creation of tailored animal models, (ii) provide safe animal cells, tissues and organs for xenotransplantation, (iii) contribute to the preservation of endangered species, and (iv) improve global food security whilst reducing the environmental impact of animal production. This review discusses recent advances that build on the conceptual legacy of nuclear transfer and – when combined with gene editing – will have transformative potential for medicine, biodiversity and sustainable agriculture. We conclude that the potential of these technologies depends on further fundamental and translational research directed at improving the efficiency and safety of these methods.
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Affiliation(s)
- Ramiro Alberio
- School of Biosciences University of Nottingham, Nottingham, UK
| | - Eckhard Wolf
- Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany
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Lin JC, Van Eenennaam AL. Electroporation-Mediated Genome Editing of Livestock Zygotes. Front Genet 2021; 12:648482. [PMID: 33927751 PMCID: PMC8078910 DOI: 10.3389/fgene.2021.648482] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 03/22/2021] [Indexed: 12/20/2022] Open
Abstract
The introduction of genome editing reagents into mammalian zygotes has traditionally been accomplished by cytoplasmic or pronuclear microinjection. This time-consuming procedure requires expensive equipment and a high level of skill. Electroporation of zygotes offers a simplified and more streamlined approach to transfect mammalian zygotes. There are a number of studies examining the parameters used in electroporation of mouse and rat zygotes. Here, we review the electroporation conditions, timing, and success rates that have been reported for mice and rats, in addition to the few reports about livestock zygotes, specifically pigs and cattle. The introduction of editing reagents at, or soon after, fertilization can help reduce the rate of mosaicism, the presence of two of more genotypes in the cells of an individual; as can the introduction of nuclease proteins rather than mRNA encoding nucleases. Mosaicism is particularly problematic in large livestock species with long generation intervals as it can take years to obtain non-mosaic, homozygous offspring through breeding. Gene knockouts accomplished via the non-homologous end joining pathway have been more widely reported and successfully accomplished using electroporation than have gene knock-ins. Delivering large DNA plasmids into the zygote is hindered by the zona pellucida (ZP), and the majority of gene knock-ins accomplished by electroporation have been using short single stranded DNA (ssDNA) repair templates, typically less than 1 kb. The most promising approach to deliver larger donor repair templates of up to 4.9 kb along with genome editing reagents into zygotes, without using cytoplasmic injection, is to use recombinant adeno-associated viruses (rAAVs) in combination with electroporation. However, similar to other methods used to deliver clustered regularly interspaced palindromic repeat (CRISPR) genome-editing reagents, this approach is also associated with high levels of mosaicism. Recent developments complementing germline ablated individuals with edited germline-competent cells offer an approach to avoid mosaicism in the germline of genome edited founder lines. Even with electroporation-mediated delivery of genome editing reagents to mammalian zygotes, there remain additional chokepoints in the genome editing pipeline that currently hinder the scalable production of non-mosaic genome edited livestock.
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Affiliation(s)
- Jason C Lin
- Department of Animal Science, University of California, Davis, Davis, CA, United States
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Abstract
Genetically modified animals, especially rodents, are widely used in biomedical research. However, non-rodent models are required for efficient translational medicine and preclinical studies. Owing to the similarity in the physiological traits of pigs and humans, genetically modified pigs may be a valuable resource for biomedical research. Somatic cell nuclear transfer (SCNT) using genetically modified somatic cells has been the primary method for the generation of genetically modified pigs. However, site-specific gene modification in porcine cells is inefficient and requires laborious and time-consuming processes. Recent improvements in gene-editing systems, such as zinc finger nucleases, transcription activator-like effector nucleases, and the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (CRISPR/Cas) system, represent major advances. The efficient introduction of site-specific modifications into cells via gene editors dramatically reduces the effort and time required to generate genetically modified pigs. Furthermore, gene editors enable direct gene modification during embryogenesis, bypassing the SCNT procedure. The application of gene editors has progressively expanded, and a range of strategies is now available for porcine gene engineering. This review provides an overview of approaches for the generation of genetically modified pigs using gene editors, and highlights the current trends, as well as the limitations, of gene editing in pigs.
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Affiliation(s)
- Fuminori Tanihara
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima 770-8513, Japan.,Center for Development of Advanced Medical Technology, Jichi Medical University, Tochigi 329-0498, Japan
| | - Maki Hirata
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima 770-8513, Japan
| | - Takeshige Otoi
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima 770-8513, Japan
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One-Step Generation of Multiple Gene-Edited Pigs by Electroporation of the CRISPR/Cas9 System into Zygotes to Reduce Xenoantigen Biosynthesis. Int J Mol Sci 2021; 22:ijms22052249. [PMID: 33668187 PMCID: PMC7956194 DOI: 10.3390/ijms22052249] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/18/2021] [Accepted: 02/20/2021] [Indexed: 02/08/2023] Open
Abstract
Xenoantigens cause hyperacute rejection and limit the success of interspecific xenografts. Therefore, genes involved in xenoantigen biosynthesis, such as GGTA1, CMAH, and B4GALNT2, are key targets to improve the outcomes of xenotransplantation. In this study, we introduced a CRISPR/Cas9 system simultaneously targeting GGTA1, CMAH, and B4GALNT2 into in vitro-fertilized zygotes using electroporation for the one-step generation of multiple gene-edited pigs without xenoantigens. First, we optimized the combination of guide RNAs (gRNAs) targeting GGTA1 and CMAH with respect to gene editing efficiency in zygotes, and transferred electroporated embryos with the optimized gRNAs and Cas9 into recipient gilts. Next, we optimized the Cas9 protein concentration with respect to the gene editing efficiency when GGTA1, CMAH, and B4GALNT2 were targeted simultaneously, and generated gene-edited pigs using the optimized conditions. We achieved the one-step generation of GGTA1/CMAH double-edited pigs and GGTA1/CMAH/B4GALNT2 triple-edited pigs. Immunohistological analyses demonstrated the downregulation of xenoantigens; however, these multiple gene-edited pigs were genetic mosaics that failed to knock out some xenoantigens. Although mosaicism should be resolved, the electroporation technique could become a primary method for the one-step generation of multiple gene modifications in pigs aimed at improving pig-to-human xenotransplantation.
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Hirata M, Wittayarat M, Tanihara F, Sato Y, Namula Z, Le QA, Lin Q, Takebayashi K, Otoi T. One-step genome editing of porcine zygotes through the electroporation of a CRISPR/Cas9 system with two guide RNAs. In Vitro Cell Dev Biol Anim 2020; 56:614-621. [PMID: 32978715 DOI: 10.1007/s11626-020-00507-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 09/08/2020] [Indexed: 11/30/2022]
Abstract
In the present study, we investigated whether electroporation could be used for one-step multiplex CRISPR/Cas9-based genome editing, targeting IL2RG and GHR in porcine embryos. First, we evaluated and selected guide RNAs (gRNAs) by analyzing blastocyst formation rates and genome editing efficiency. This was performed in embryos electroporated with one of three different gRNAs targeting IL2RG or one of two gRNAs targeting GHR. No significant differences in embryo development rates were found between control embryos and those subjected to electroporation, irrespective of the target gene. Two gRNAs targeting IL2RG (nos. 2 and 3) contributed to an increased biallelic mutation rate in porcine blastocysts compared with gRNA no. 1. There were no significant differences in the mutation rates between the two gRNAs targeting GHR. In our next experiment, the mutation efficiency and the development of embryos simultaneously electroporated with gRNAs targeting IL2RG and GHR were investigated. Similar embryo development rates were observed between embryos electroporated with two gRNAs and control embryos. When IL2RG-targeting gRNA no. 2 was used with GHR-targeting gRNAs no. 1 or no. 2, a significantly higher double biallelic mutation rate was observed than with IL2RG-targeting gRNA no. 3. In conclusion, we demonstrate the feasibility of using electroporation to transfer multiple gRNAs and Cas9 into porcine zygotes, enabling the double biallelic mutation of multiple genes with favorable embryo survival.
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Affiliation(s)
- Maki Hirata
- Laboratory of Animal Reproduction, Faculty of Bioscience and Bioindustry, Tokushima University, 2272-1 Ishii, Myozai-gun, Tokushima, 779-3233, Japan
| | - Manita Wittayarat
- Faculty of Veterinary Science, Prince of Songkla University, Songkhla, Thailand
| | - Fuminori Tanihara
- Laboratory of Animal Reproduction, Faculty of Bioscience and Bioindustry, Tokushima University, 2272-1 Ishii, Myozai-gun, Tokushima, 779-3233, Japan.
| | - Yoko Sato
- School of Biological Science, Tokai University, Sapporo, Japan
| | - Zhao Namula
- College of Agricultural Science, Guangdong Ocean University, Guangdong, China
| | - Quynh Anh Le
- Laboratory of Animal Reproduction, Faculty of Bioscience and Bioindustry, Tokushima University, 2272-1 Ishii, Myozai-gun, Tokushima, 779-3233, Japan
| | - Qingyi Lin
- Laboratory of Animal Reproduction, Faculty of Bioscience and Bioindustry, Tokushima University, 2272-1 Ishii, Myozai-gun, Tokushima, 779-3233, Japan
| | - Koki Takebayashi
- Laboratory of Animal Reproduction, Faculty of Bioscience and Bioindustry, Tokushima University, 2272-1 Ishii, Myozai-gun, Tokushima, 779-3233, Japan
| | - Takeshige Otoi
- Laboratory of Animal Reproduction, Faculty of Bioscience and Bioindustry, Tokushima University, 2272-1 Ishii, Myozai-gun, Tokushima, 779-3233, Japan
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