Modelling urea cycle disorders using iPSCs

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

The urea cycle is a liver-based pathway enabling disposal of nitrogen waste. Urea cycle disorders (UCDs) are inherited metabolic diseases caused by deficiency of enzymes or transporters involved in the urea cycle and have a prevalence of 1:35,000 live births. Patients present recurrent acute hyperammonaemia, which causes high rate of death and neurological sequelae. Long-term therapy relies on a protein-restricted diet and ammonia scavenger drugs. Currently, liver transplantation is the only cure. Hence, high unmet needs require the identification of effective methods to model these diseases to generate innovative therapeutics. Advances in both induced pluripotent stem cells (iPSCs) and genome editing technologies have provided an invaluable opportunity to model patient-specific phenotypes in vitro by creating patients’ avatar models, to investigate the pathophysiology, uncover novel therapeutic targets and provide a platform for drug discovery. This review summarises the progress made thus far in generating 2- and 3-dimensional iPSCs models for UCDs, the challenges encountered and how iPSCs offer future avenues for innovation in developing the next-generation of therapies for UCDs.

Related collections

Most cited references 129

Record: found
Abstract: found
Article: not found

Standards and Guidelines for the Interpretation of Sequence Variants: A Joint Consensus Recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology

Sue Richards, Nazneen Aziz, Sherri Bale … (2015)

The American College of Medical Genetics and Genomics (ACMG) previously developed guidance for the interpretation of sequence variants. 1 In the past decade, sequencing technology has evolved rapidly with the advent of high-throughput next generation sequencing. By adopting and leveraging next generation sequencing, clinical laboratories are now performing an ever increasing catalogue of genetic testing spanning genotyping, single genes, gene panels, exomes, genomes, transcriptomes and epigenetic assays for genetic disorders. By virtue of increased complexity, this paradigm shift in genetic testing has been accompanied by new challenges in sequence interpretation. In this context, the ACMG convened a workgroup in 2013 comprised of representatives from the ACMG, the Association for Molecular Pathology (AMP) and the College of American Pathologists (CAP) to revisit and revise the standards and guidelines for the interpretation of sequence variants. The group consisted of clinical laboratory directors and clinicians. This report represents expert opinion of the workgroup with input from ACMG, AMP and CAP stakeholders. These recommendations primarily apply to the breadth of genetic tests used in clinical laboratories including genotyping, single genes, panels, exomes and genomes. This report recommends the use of specific standard terminology: ‘pathogenic’, ‘likely pathogenic’, ‘uncertain significance’, ‘likely benign’, and ‘benign’ to describe variants identified in Mendelian disorders. Moreover, this recommendation describes a process for classification of variants into these five categories based on criteria using typical types of variant evidence (e.g. population data, computational data, functional data, segregation data, etc.). Because of the increased complexity of analysis and interpretation of clinical genetic testing described in this report, the ACMG strongly recommends that clinical molecular genetic testing should be performed in a CLIA-approved laboratory with results interpreted by a board-certified clinical molecular geneticist or molecular genetic pathologist or equivalent.

0 comments Cited 7076 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Induction of pluripotent stem cells from adult human fibroblasts by defined factors.

Kazutoshi Takahashi, Koji TANABE, Mari Ohnuki … (2007)

Successful reprogramming of differentiated human somatic cells into a pluripotent state would allow creation of patient- and disease-specific stem cells. We previously reported generation of induced pluripotent stem (iPS) cells, capable of germline transmission, from mouse somatic cells by transduction of four defined transcription factors. Here, we demonstrate the generation of iPS cells from adult human dermal fibroblasts with the same four factors: Oct3/4, Sox2, Klf4, and c-Myc. Human iPS cells were similar to human embryonic stem (ES) cells in morphology, proliferation, surface antigens, gene expression, epigenetic status of pluripotent cell-specific genes, and telomerase activity. Furthermore, these cells could differentiate into cell types of the three germ layers in vitro and in teratomas. These findings demonstrate that iPS cells can be generated from adult human fibroblasts.

0 comments Cited 2064 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Programmable editing of a target base in genomic DNA without double-stranded DNA cleavage

Alexis Komor, Yongjoo Kim, Michael Packer … (2016)

Current genome-editing technologies introduce double-stranded (ds) DNA breaks at a target locus as the first step to gene correction. 1,2 Although most genetic diseases arise from point mutations, current approaches to point mutation correction are inefficient and typically induce an abundance of random insertions and deletions (indels) at the target locus from the cellular response to dsDNA breaks. 1,2 Here we report the development of base editing, a new approach to genome editing that enables the direct, irreversible conversion of one target DNA base into another in a programmable manner, without requiring dsDNA backbone cleavage or a donor template. We engineered fusions of CRISPR/Cas9 and a cytidine deaminase enzyme that retain the ability to be programmed with a guide RNA, do not induce dsDNA breaks, and mediate the direct conversion of cytidine to uridine, thereby effecting a C→T (or G→A) substitution. The resulting “base editors” convert cytidines within a window of approximately five nucleotides (nt), and can efficiently correct a variety of point mutations relevant to human disease. In four transformed human and murine cell lines, second- and third-generation base editors that fuse uracil glycosylase inhibitor (UGI), and that use a Cas9 nickase targeting the non-edited strand, manipulate the cellular DNA repair response to favor desired base-editing outcomes, resulting in permanent correction of ∼15-75% of total cellular DNA with minimal (typically ≤ 1%) indel formation. Base editing expands the scope and efficiency of genome editing of point mutations.

0 comments Cited 1320 times – based on 0 reviews      Review now

Bookmark

All references

Author and article information

Contributors

Julien Baruteau:

ORCID: http://orcid.org/0000-0003-0582-540X

j.baruteau@ucl.ac.uk

Journal

Journal ID (nlm-ta): NPJ Regen Med

Journal ID (iso-abbrev): NPJ Regen Med

Title: NPJ Regenerative Medicine

Publisher: Nature Publishing Group UK (London )

ISSN (Electronic): 2057-3995

Publication date (Electronic): 26 September 2022

Publication date PMC-release: 26 September 2022

Publication date Collection: 2022

Volume: 7

Electronic Location Identifier: 56

Affiliations

[1 ]GRID grid.83440.3b, ISNI 0000000121901201, Genetics and Genomic Medicine Department, Great Ormond Street Institute of Child Health, , University College London, ; London, UK

[2 ]GRID grid.451056.3, ISNI 0000 0001 2116 3923, National Institute of Health Research Great Ormond Street Biomedical Research Centre, ; London, UK

[3 ]GRID grid.424537.3, ISNI 0000 0004 5902 9895, Metabolic Medicine Department, , Great Ormond Street Hospital for Children NHS Foundation Trust, ; London, UK

Author information

Claire Duff http://orcid.org/0000-0002-5332-0337

Julien Baruteau http://orcid.org/0000-0003-0582-540X

Article

Publisher ID: 252

DOI: 10.1038/s41536-022-00252-5

PMC ID: 9513077

PubMed ID: 36163209

SO-VID: 2890d2ae-e386-4d1e-aab3-38ad31e3a62f

License:

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

History

Date received : 3 February 2022

Date accepted : 10 August 2022

Funding

Funded by: FundRef https://doi.org/10.13039/501100000265, RCUK | Medical Research Council (MRC);

Award ID: MR/T008024/1

Award Recipient : Julien Baruteau

Funded by: NIHR Great Ormond Street Hospital Biomedical Research Centre

Custom metadata

Keywords: induced pluripotent stem cells,experimental models of disease,metabolic disorders,mechanisms of disease,stem-cell differentiation

Data availability:

Keywords: induced pluripotent stem cells, experimental models of disease, metabolic disorders, mechanisms of disease, stem-cell differentiation

Modelling urea cycle disorders using iPSCs

Read this article at

Abstract

Related collections

Genome Engineering using CRISPR

Most cited references 129

Standards and Guidelines for the Interpretation of Sequence Variants: A Joint Consensus Recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology

Induction of pluripotent stem cells from adult human fibroblasts by defined factors.

Programmable editing of a target base in genomic DNA without double-stranded DNA cleavage

Author and article information

Contributors

Journal

Affiliations

Author information

Article

History

Funding

Categories

Custom metadata

Comments

Comment on this article

Similar content 500

Cited by 4

Most referenced authors 3,048