scholarly journals Zebrafish models for human ALA-dehydratase-deficient porphyria (ADP) and hereditary coproporphyria (HCP) generated with TALEN and CRISPR-Cas9

2017 ◽  
Author(s):  
Shuqing Zhang ◽  
Jiao Meng ◽  
Zhijie Niu ◽  
Yikai Huang ◽  
Jingjing Wang ◽  
...  
Keyword(s):  
Genome Editing ◽  
Genetic Disorders ◽  
Genetic Diseases ◽  
Heme Biosynthesis ◽  
Transcription Activator ◽  
Uroporphyrinogen Decarboxylase ◽  
Zebrafish Model ◽  
Altered Expression ◽  
Coproporphyrinogen Oxidase ◽  
Ala Dehydratase

ABSTRACTDefects in the enzymes involved in heme biosynthesis result in a group of human metabolic genetic disorders known as porphyrias. Using a zebrafish model for human hepatoerythropoietic porphyria (HEP), caused by defective uroporphyrinogen decarboxylase (Urod), the fifth enzyme in the heme biosynthesis pathway, we recently have found a novel aspect of porphyria pathogenesis. However, no hereditable zebrafish models with genetic mutations ofaladandcpox, encoding the second enzyme delta-aminolevulinate dehydratase (Alad) and the sixth enzyme coproporphyrinogen oxidase (Cpox), have been established to date. Here we employed site-specific genome-editing tools transcription activator-like effector nuclease (TALEN) and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) to generate zebrafish mutants foraladandcpox. These zebrafish mutants display phenotypes of heme deficiency, hypochromia, abnormal erythrocytic maturation and accumulation of heme precursor intermediates, reminiscent of human ALA-dehydratase-deficient porphyria (ADP) and hereditary coproporphyrian (HCP), respectively. Further, we observed altered expression of genes involved in heme biosynthesis and degradation and particularly down-regulation of exocrine pancreatic zymogens in ADP (alad-/-) and HCP (cpox-/-) fishes. These two zebrafish porphyria models can survive at least 7 days and thus provide invaluable resources for elucidating novel pathological aspects of porphyrias, evaluating mutated forms of humanALADandCPOX, discovering new therapeutic targets and developing effective drugs for these complex genetic diseases. Our studies also highlight generation of zebrafish models for human diseases with two versatile genome-editing tools.

scholarly journals Fluorescent in vivo editing reporter (FIVER): A novel multispectral reporter of in vivo genome editing

2020 ◽  
Author(s):  
Peter A. Tennant ◽  
Robert G. Foster ◽  
Daniel O. Dodd ◽  
Ieng Fong Sou ◽  
Fraser McPhie ◽  
...  
Keyword(s):  
Genome Editing ◽  
Genetic Disorders ◽  
Genetic Diseases ◽  
Primary Cells ◽  
Genetic Changes ◽  
Organ Systems ◽  
Therapeutic Development ◽  
The Right ◽  
Small Molecule Modulators

AbstractAdvances in genome editing technologies have created opportunities to treat rare genetic diseases, which are often overlooked in terms of therapeutic development. Nonetheless, substantial challenges remain: namely, achieving therapeutically beneficial levels and kinds of editing in the right cell type(s). Here we describe the development of FIVER (fluorescent in vivo editing reporter) — a modular toolkit for in vivo detection of genome editing with distinct fluorescent read-outs for non-homologous end-joining (NHEJ), homology-directed repair (HDR) and homology-independent targeted integration (HITI). We demonstrate that fluorescent outcomes reliably report genetic changes following editing with diverse genome editors in primary cells, organoids and in vivo. We show the potential of FIVER for high-throughput unbiased screens, from small molecule modulators of genome editing outcomes in primary cells through to genome-wide in vivo CRISPR cancer screens. Importantly, we demonstrate its in vivo application in postnatal organ systems of interest for genetic therapies — retina and liver. FIVER will broadly help expedite the development of therapeutic genome surgery for many genetic disorders.

scholarly journals In Vivo Genome Editing as a Therapeutic Approach

2018 ◽  
Vol 19 (9) ◽  
pp. 2721 ◽  
Author(s):  
Beatrice Ho ◽  
Sharon Loh ◽  
Woon Chan ◽  
Boon Soh
Keyword(s):  
Genome Editing ◽  
Genome Engineering ◽  
Genetic Diseases ◽  
Gene Mutations ◽  
Genetic Mutation ◽  
Zinc Finger Nucleases ◽  
Transcription Activator ◽  
Therapeutic Benefits ◽  
A Genome

Genome editing has been well established as a genome engineering tool that enables researchers to establish causal linkages between genetic mutation and biological phenotypes, providing further understanding of the genetic manifestation of many debilitating diseases. More recently, the paradigm of genome editing technologies has evolved to include the correction of mutations that cause diseases via the use of nucleases such as zinc-finger nucleases (ZFN), transcription activator-like effector nucleases (TALENs), and more recently, Cas9 nuclease. With the aim of reversing disease phenotypes, which arise from somatic gene mutations, current research focuses on the clinical translatability of correcting human genetic diseases in vivo, to provide long-term therapeutic benefits and potentially circumvent the limitations of in vivo cell replacement therapy. In this review, in addition to providing an overview of the various genome editing techniques available, we have also summarized several in vivo genome engineering strategies that have successfully demonstrated disease correction via in vivo genome editing. The various benefits and challenges faced in applying in vivo genome editing in humans will also be discussed.

scholarly journals IMPROVING THE FUNCTION OF CRISPR-CAS9 FOR GENOME EDITING THERAPY: EDITING THE EDITOR

2017 ◽  
Vol 4 (1) ◽  
pp. 44
Author(s):  
Alva Sahiri Alexander Supit
Keyword(s):  
Genome Editing ◽  
Viral Vectors ◽  
Gene Editing ◽  
Genetic Disorders ◽  
Genetic Diseases ◽  
End Joining ◽  
Guide Rna ◽  
Homology Directed Repair ◽  
Short Palindromic Repeat ◽  
Active Research

Meningkatkan Fungsi CRISPR-Cas9 untuk Terapi Pengeditan GenPengeditan gen menjadi mudah dilakukan sejak ditemukannya clustered regularly interspaced short palindromic repeat (CRISPR) dan CRISPR-associated protein 9 (Cas9) sebagai alat untuk menyunting gen suatu organisme. Sebagian besar penyakit genetik tidak dapat disembuhkan secara kausal dengan terapi yang ada, maka pengeditan gen merupakan suatu cara yang prospektif dalam terapi medis di masa depan. Sayangnya, pengeditan gen dengan Cas9 yang ada saat ini masih memiliki banyak kelemahan, yaitu: 1) kurang spesifik, di mana RNA pemandu dapat berikatan dengan beberapa segmen pada genom manusia, sehingga memungkinkan terjadinya salah target; 2) kurang efisien, karena sekalipun telah berhasil memotong utas ganda DNA, kebanyakan penyambungan kembali akan dilakukan secara non-homology end joining (NHEJ), yang justru meningkatkan peluang terjadinya mutasi; 3) sulit disalurkan ke dalam inti sel karena berbagai sawar fisiologis maupun biokimiawi. Tulisan ini akan membahas perkembangan terkini dalam mengatasi ketiga masalah di atas. Untuk meningkatkan spesifisitas, dapat dilakukan modifikasi RNA pemandu dan struktur Cas9. Efisiensi dapat ditingkatkan dengan meningkatkan peluang terjadinya homology-directed repair dibandingkan NHEJ, sedangkan untuk meningkatkan distribusi ke dalam sel, dapat digunakan berbagai macam vektor, seperti virus dan nanopartikel. CRISPR-Cas9 merupakan area yang aktif diteliti dalam bidang biosains, dan dalam waktu dekat, diharapkan dapat dimanfaatkan dalam bidang klinik.Kata kunci: CRISPR, Cas9, efektivitas, spesifisitas, terapi genABSTRACTGene editing has become reasonably easy since the discovery of clustered regularly interspaced short palindromic repeat (CRISPR) and CRISPR-associated protein 9 (Cas9). Most genetic diseases cannot be treated causally, and currently available therapies are mainly symptom-based. To treat the etiology of genetic diseases, a firm gene editing therapy is necessary to be established. This posits Cas9-facilitated gene editing as a prospective modality to become a clinically approved therapy in the future to treat genetic disorders. However, until recently, Cas9-based genome editing is still facing several hurdles, including low specificity, low effectiveness, and difficult delivery. Currently available Cas9 nucleases are able to bind to non-specific DNA sequence and produce non-specific cleavage. The efficiency has been relatively low due to the preference of non-homologous end-joining (NHEJ) over homology-directed repair (HDR) by the host cell. Furthermore, in order to deliver Cas9 into the nucleus, multiple physiological barriers have to be overcome. This review discussed recent developments in tackling these three hurdles, ranging from designing the guide RNA using multiple bioinformatics tools, modifying Cas9 structure, as well as packaging the nuclease-guide RNA complex into viral vectors and nanoparticles. Considering the active research on this area, it is expected that CRISPR/Cas9 can be utilized as a clinical therapy in the near future.Received: 02 June 2017        Accepted: 07 July 2017        Published: 19 July 2017

scholarly journals Development of BCR-ABL1 Transgenic Zebrafish Model Reproducing Chronic Myeloid Leukemia (CML) Like-Disease and Providing a New Insight into CML Mechanisms

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 445
Author(s):  
Daniela Zizioli ◽  
Simona Bernardi ◽  
Marco Varinelli ◽  
Mirko Farina ◽  
Luca Mignani ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Fusion Gene ◽  
Philadelphia Chromosome ◽  
Leukemic Cells ◽  
Transgenic Zebrafish ◽  
Hematopoietic Tissue ◽  
Zebrafish Model ◽  
Altered Expression

Zebrafish has proven to be a versatile and reliable experimental in vivo tool to study human hematopoiesis and model hematological malignancies. Transgenic technologies enable the generation of specific leukemia types by the expression of human oncogenes under specific promoters. Using this technology, a variety of myeloid and lymphoid malignancies zebrafish models have been described. Chronic myeloid leukemia (CML) is a clonal myeloproliferative neoplasia characterized by the BCR-ABL1 fusion gene, derived from the t (9;22) translocation causing the Philadelphia Chromosome (Ph). The BCR-ABL1 protein is a constitutively activated tyrosine kinas inducing the leukemogenesis and resulting in an accumulation of immature leukemic cells into bone marrow and peripheral blood. To model Ph+ CML, a transgenic zebrafish line expressing the human BCR-ABL1 was generated by the Gal4/UAS system, and then crossed with the hsp70-Gal4 transgenic line. The new line named (BCR-ABL1pUAS:CFP/hsp70-Gal4), presented altered expression of hematopoietic markers during embryonic development compared to controls and transgenic larvae showed proliferating hematopoietic cells in the caudal hematopoietic tissue (CHT). The present transgenic zebrafish would be a robust CML model and a high-throughput drug screening tool.

scholarly journals Evolution and Application of Genome Editing Techniques for Achieving Food and Nutritional Security

2021 ◽  
Vol 22 (11) ◽  
pp. 5585
Author(s):  
Sajid Fiaz ◽  
Sunny Ahmar ◽  
Sajjad Saeed ◽  
Aamir Riaz ◽  
Freddy Mora-Poblete ◽  
...  
Keyword(s):  
Abiotic Stress ◽  
Food Security ◽  
Plant Breeding ◽  
Genome Editing ◽  
Crop Improvement ◽  
Hybrid Seed Production ◽  
Biotic And Abiotic Stress ◽  
Transcription Activator ◽  
Protein System ◽  
Breeding Techniques

A world with zero hunger is possible only through a sustainable increase in food production and distribution and the elimination of poverty. Scientific, logistical, and humanitarian approaches must be employed simultaneously to ensure food security, starting with farmers and breeders and extending to policy makers and governments. The current agricultural production system is facing the challenge of sustainably increasing grain quality and yield and enhancing resistance to biotic and abiotic stress under the intensifying pressure of climate change. Under present circumstances, conventional breeding techniques are not sufficient. Innovation in plant breeding is critical in managing agricultural challenges and achieving sustainable crop production. Novel plant breeding techniques, involving a series of developments from genome editing techniques to speed breeding and the integration of omics technology, offer relevant, versatile, cost-effective, and less time-consuming ways of achieving precision in plant breeding. Opportunities to edit agriculturally significant genes now exist as a result of new genome editing techniques. These range from random (physical and chemical mutagens) to non-random meganucleases (MegaN), zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), clustered regularly interspaced short palindromic repeats (CRISPR)/associated protein system 9 (CRISPR/Cas9), the CRISPR system from Prevotella and Francisella1 (Cpf1), base editing (BE), and prime editing (PE). Genome editing techniques that promote crop improvement through hybrid seed production, induced apomixis, and resistance to biotic and abiotic stress are prioritized when selecting for genetic gain in a restricted timeframe. The novel CRISPR-associated protein system 9 variants, namely BE and PE, can generate transgene-free plants with more frequency and are therefore being used for knocking out of genes of interest. We provide a comprehensive review of the evolution of genome editing technologies, especially the application of the third-generation genome editing technologies to achieve various plant breeding objectives within the regulatory regimes adopted by various countries. Future development and the optimization of forward and reverse genetics to achieve food security are evaluated.

scholarly journals The Importance of Early Detection of Genetic Diseases

2021 ◽  
Vol 4 (2) ◽  
pp. 133-141
Author(s):  
Suma Elcy Varghese ◽  
Rana Hassan Mohammad El Otol ◽  
Fatma Sultan Al Olama ◽  
Salah Ahmad Mohamed Elbadawi
Keyword(s):  
Early Detection ◽  
Newborn Screening ◽  
Health Authority ◽  
Genetic Screening ◽  
Screening Program ◽  
Genetic Disorders ◽  
Genetic Diseases ◽  
Inborn Errors ◽  
The Usa ◽  
Premarital Screening

<b><i>Background:</i></b> Early detection of diseases in newborn may help in early intervention and treatment, which may either cure the disease or improve the outcome of the patient. Dubai’s Health Authority has a newborn screening program which includes screening for metabolic and genetic conditions, for hearing and vision, and for congenital heart disease. <b><i>Objectives:</i></b> The objectives of this study are to assess the outcome of the newborn genetic screening program, to correlate the association between the outcome of the program and demographic variables and to find out the percentage of the number of infants who were confirmed to have the genetic disease (by confirmatory tests) out of the total infants who had positive screening test results. <b><i>Methods:</i></b> During the period of the study from January 2018 to December 2018, a total of 7,027 newborns were tested in Dubai Health Authority facilities by the newborn genetic screening program (known as the “Step One Screening”). Blood samples were collected by heel prick on a collection paper. All samples were transported to PerkinElmer Genomics in the USA where the tests were done. The genetic disorders identified were correlated with different variables like gender and nationality. The data were entered in an excel sheet and analyzed by using SPSS software. All infants aged 0–3 months who have done newborn genetic screening at Dubai Health Authority facilities between January and December 2018 were included. <b><i>Results:</i></b> The incidence of screened disorders was 1:7,027 for congenital adrenal hyperplasia, 1:1,757 for congenital hypothyroidism, 1:1,757 for inborn errors of metabolism, 1:2,342 for biotinidase deficiency, 1:1,171 for hemoglobinopathies, 1:12 for hemoglobinopathy traits, and 1:10 for different genetic mutations of G6PD deficiency. <b><i>Conclusions:</i></b> There is a high incidence of different genetic diseases detected by newborn screening. These results justify unifying the program in the UAE and preventive programs like premarital screening and genetic counseling.

The ethics of genome editing in the clinic: A dose of realism for healthcare leaders

2017 ◽  
Vol 30 (3) ◽  
pp. 159-163
Author(s):  
Tania Bubela ◽  
Yael Mansour ◽  
Dianne Nicol
Keyword(s):  
Genome Editing ◽  
Germ Line ◽  
Genetic Diseases ◽  
Somatic Cells ◽  
Clinical Translation ◽  
Preclinical Research ◽  
Societal Issues ◽  
Realistic Assessment ◽  
Healthcare Leaders

Genome editing technologies promise therapeutic advances for genetic diseases. We discuss the ethical and societal issues raised by these technologies, including their use in preclinical research, their potential to address mutations in somatic cells, and their potential to make germ line alterations that may be passed to subsequent generations. We call for a proportionate response from health leaders based on a realistic assessment of benefits, risks, and timelines for clinical translation.

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