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Roy KR, Smith JD, Li S, Vonesch SC, Nguyen M, Burnett WT, Orsley KM, Lee CS, Haber JE, St Onge RP, Steinmetz LM. Dissecting quantitative trait nucleotides by saturation genome editing. bioRxiv 2024:2024.02.02.577784. [PMID: 38352467 PMCID: PMC10862795 DOI: 10.1101/2024.02.02.577784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
Genome editing technologies have the potential to transform our understanding of how genetic variation gives rise to complex traits through the systematic engineering and phenotypic characterization of genetic variants. However, there has yet to be a system with sufficient efficiency, fidelity, and throughput to comprehensively identify causal variants at the genome scale. Here we explored the ability of templated CRISPR editing systems to install natural variants genome-wide in budding yeast. We optimized several approaches to enhance homology-directed repair (HDR) with donor DNA templates, including donor recruitment to target sites, single-stranded donor production by bacterial retrons, and in vivo plasmid assembly. We uncovered unique advantages of each system that we integrated into a single superior system named MAGESTIC 3.0. We used MAGESTIC 3.0 to dissect causal variants residing in 112 quantitative trait loci across 32 environmental conditions, revealing an enrichment for missense variants and loci with multiple causal variants. MAGESTIC 3.0 will facilitate the functional analysis of the genome at single-nucleotide resolution and provides a roadmap for improving template-based genome editing systems in other organisms.
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Affiliation(s)
- Kevin R Roy
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Justin D Smith
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Shengdi Li
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
| | - Sibylle C Vonesch
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
- Laboratory for Genome Editing and Systems Genetics, VIB-KU Leuven Center for Microbiology, Leuven, Belgium
- KU Leuven Center for Microbial and Plant Genetics, Department M2S, Leuven, Belgium
| | - Michelle Nguyen
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Wallace T Burnett
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Kevin M Orsley
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Cheng-Sheng Lee
- Brandeis University, Rosenstiel Basic Medical Sciences Research Center and Department of Biology, Waltham, MA
| | - James E Haber
- Brandeis University, Rosenstiel Basic Medical Sciences Research Center and Department of Biology, Waltham, MA
| | - Robert P St Onge
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Biochemistry, Stanford University School of Medicine, Stanford, California, USA
| | - Lars M Steinmetz
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
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Hale JJ, Matsui T, Goldstein I, Mullis MN, Roy KR, Ville CN, Miller D, Wang C, Reynolds T, Steinmetz LM, Levy SF, Ehrenreich IM. Genome-scale analysis of interactions between genetic perturbations and natural variation. bioRxiv 2024:2023.05.06.539663. [PMID: 38293072 PMCID: PMC10827069 DOI: 10.1101/2023.05.06.539663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Interactions between genetic perturbations and segregating loci can cause perturbations to show different phenotypic effects across genetically distinct individuals. To study these interactions on a genome scale in many individuals, we used combinatorial DNA barcode sequencing to measure the fitness effects of 7,700 CRISPRi perturbations targeting 1,712 distinct genes in 169 yeast cross progeny (or segregants). We identified 460 genes whose perturbation has different effects across segregants. Several factors caused perturbations to show variable effects, including baseline segregant fitness, the mean effect of a perturbation across segregants, and interacting loci. We mapped 234 interacting loci and found four hub loci that interact with many different perturbations. Perturbations that interact with a given hub exhibit similar epistatic relationships with the hub and show enrichment for cellular processes that may mediate these interactions. These results suggest that an individual's response to perturbations is shaped by a network of perturbation-locus interactions that cannot be measured by approaches that examine perturbations or natural variation alone.
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Affiliation(s)
- Joseph J. Hale
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Takeshi Matsui
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Ilan Goldstein
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Martin N. Mullis
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Kevin R. Roy
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Chris Ne Ville
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Darach Miller
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Charley Wang
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Trevor Reynolds
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Lars M. Steinmetz
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
| | - Sasha F. Levy
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
- Present address: BacStitch DNA, Los Altos, California, USA
| | - Ian M. Ehrenreich
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
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Roy KR, Gabunilas J, Neutel D, Ai M, Yeh Z, Samson J, Lyu G, Chanfreau GF. Splicing factor Prp18p promotes genome-wide fidelity of consensus 3'-splice sites. Nucleic Acids Res 2023; 51:12428-12442. [PMID: 37956322 PMCID: PMC10711555 DOI: 10.1093/nar/gkad968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 09/21/2023] [Accepted: 10/24/2023] [Indexed: 11/15/2023] Open
Abstract
The fidelity of splice site selection is critical for proper gene expression. In particular, proper recognition of 3'-splice site (3'SS) sequences by the spliceosome is challenging considering the low complexity of the 3'SS consensus sequence YAG. Here, we show that absence of the Prp18p splicing factor results in genome-wide activation of alternative 3'SS in S. cerevisiae, including highly unusual non-YAG sequences. Usage of these non-canonical 3'SS in the absence of Prp18p is enhanced by upstream poly(U) tracts and by their potential to interact with the first intronic nucleoside, allowing them to dock in the spliceosome active site instead of the normal 3'SS. The role of Prp18p in 3'SS fidelity is facilitated by interactions with Slu7p and Prp8p, but cannot be fulfilled by Slu7p, identifying a unique role for Prp18p in 3'SS fidelity. This fidelity function is synergized by the downstream proofreading activity of the Prp22p helicase, but is independent from another late splicing helicase, Prp43p. Our results show that spliceosomes exhibit remarkably relaxed 3'SS sequence usage in the absence of Prp18p and identify a network of spliceosomal interactions centered on Prp18p which are required to promote the fidelity of the recognition of consensus 3'SS sequences.
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Affiliation(s)
- Kevin R Roy
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Jason Gabunilas
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA
| | - Dean Neutel
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA
| | - Michelle Ai
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA
| | - Zoe Yeh
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA
| | - Joyce Samson
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA
| | - Guochang Lyu
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA
| | - Guillaume F Chanfreau
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA
- Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA, USA
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Johansson SA, Dulermo T, Jann C, Smith JD, Pryszlak A, Pignede G, Schraivogel D, Colavizza D, Desfougères T, Rave C, Farwick A, Merten CA, Roy KR, Wei W, Steinmetz LM. Large scale microfluidic CRISPR screening for increased amylase secretion in yeast. Lab Chip 2023; 23:3704-3715. [PMID: 37483015 PMCID: PMC7614956 DOI: 10.1039/d3lc00111c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
Key to our ability to increase recombinant protein production through secretion is a better understanding of the pathways that interact to translate, process and export mature proteins to the surrounding environment, including the supporting cellular machinery that supplies necessary energy and building blocks. By combining droplet microfluidic screening with large-scale CRISPR libraries that perturb the expression of the majority of coding and non-coding genes in S. cerevisiae, we identified 345 genes for which an increase or decrease in gene expression resulted in increased secretion of α-amylase. Our results show that modulating the expression of genes involved in the trafficking of vesicles, endosome to Golgi transport, the phagophore assembly site, the cell cycle and energy supply improve α-amylase secretion. Besides protein-coding genes, we also find multiple long non-coding RNAs enriched in the vicinity of genes associated with endosomal, Golgi and vacuolar processes. We validated our results by overexpressing or deleting selected genes, which resulted in significant improvements in α-amylase secretion. The advantages, in terms of precision and speed, inherent to CRISPR based perturbations, enables iterative testing of new strains for increased protein secretion.
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Affiliation(s)
- S Andreas Johansson
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany.
| | - Thierry Dulermo
- Lesaffre Institute of Science & Technology, Lesaffre, 59700 Marcq-en-Baroeul, France
| | - Cosimo Jann
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany.
| | - Justin D Smith
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
| | - Anna Pryszlak
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany.
| | - Georges Pignede
- Lesaffre Institute of Science & Technology, Lesaffre, 59700 Marcq-en-Baroeul, France
| | - Daniel Schraivogel
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany.
| | - Didier Colavizza
- Lesaffre Institute of Science & Technology, Lesaffre, 59700 Marcq-en-Baroeul, France
| | - Thomas Desfougères
- Lesaffre Institute of Science & Technology, Lesaffre, 59700 Marcq-en-Baroeul, France
| | - Christophe Rave
- Lesaffre Institute of Science & Technology, Lesaffre, 59700 Marcq-en-Baroeul, France
| | - Alexander Farwick
- Lesaffre Institute of Science & Technology, Lesaffre, 59700 Marcq-en-Baroeul, France
| | - Christoph A Merten
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany.
| | - Kevin R Roy
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
| | - Wu Wei
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
| | - Lars M Steinmetz
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany.
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
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5
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Neumayer G, Torkelson JL, Li S, McCarthy K, Zhen HH, Vangipuram M, Jackow J, Rami A, Hansen C, Guo Z, Gaddam S, Pappalardo A, Li L, Cramer A, Roy KR, Nguyen TM, Tanabe K, McGrath PS, Bruckner A, Bilousova G, Roop D, Bailey I, Tang JY, Christiano A, Steinmetz LM, Wernig M, Oro AE. A scalable, GMP-compatible, autologous organotypic cell therapy for Dystrophic Epidermolysis Bullosa. bioRxiv 2023:2023.02.28.529447. [PMID: 36909618 PMCID: PMC10002612 DOI: 10.1101/2023.02.28.529447] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
Background Gene editing in induced pluripotent stem (iPS) cells has been hailed to enable new cell therapies for various monogenetic diseases including dystrophic epidermolysis bullosa (DEB). However, manufacturing, efficacy and safety roadblocks have limited the development of genetically corrected, autologous iPS cell-based therapies. Methods We developed Dystrophic Epidermolysis Bullosa Cell Therapy (DEBCT), a new generation GMP-compatible (cGMP), reproducible, and scalable platform to produce autologous clinical-grade iPS cell-derived organotypic induced skin composite (iSC) grafts to treat incurable wounds of patients lacking type VII collagen (C7). DEBCT uses a combined high-efficiency reprogramming and CRISPR-based genetic correction single step to generate genome scar-free, COL7A1 corrected clonal iPS cells from primary patient fibroblasts. Validated iPS cells are converted into epidermal, dermal and melanocyte progenitors with a novel 2D organoid differentiation protocol, followed by CD49f enrichment and expansion to minimize maturation heterogeneity. iSC product characterization by single cell transcriptomics was followed by mouse xenografting for disease correcting activity at 1 month and toxicology analysis at 1-6 months. Culture-acquired mutations, potential CRISPR-off targets, and cancer-driver variants were evaluated by targeted and whole genome sequencing. Findings iPS cell-derived iSC grafts were reproducibly generated from four recessive DEB patients with different pathogenic mutations. Organotypic iSC grafts onto immune-compromised mice developed into stable stratified skin with functional C7 restoration. Single cell transcriptomic characterization of iSCs revealed prominent holoclone stem cell signatures in keratinocytes and the recently described Gibbin-dependent signature in dermal fibroblasts. The latter correlated with enhanced graftability. Multiple orthogonal sequencing and subsequent computational approaches identified random and non-oncogenic mutations introduced by the manufacturing process. Toxicology revealed no detectable tumors after 3-6 months in DEBCT-treated mice. Interpretation DEBCT successfully overcomes previous roadblocks and represents a robust, scalable, and safe cGMP manufacturing platform for production of a CRISPR-corrected autologous organotypic skin graft to heal DEB patient wounds.
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Affiliation(s)
- Gernot Neumayer
- Institute for Stem Cell Biology and Regenerative Medicine, Department of Pathology, and Department of Chemical and Systems Biology
| | - Jessica L. Torkelson
- Program in Epithelial Biology and Department of Dermatology
- Center for Definitive and Curative Medicine
| | - Shengdi Li
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, 69117 Heidelberg, Germany
| | - Kelly McCarthy
- Program in Epithelial Biology and Department of Dermatology
- Center for Definitive and Curative Medicine
| | - Hanson H. Zhen
- Program in Epithelial Biology and Department of Dermatology
- Center for Definitive and Curative Medicine
| | - Madhuri Vangipuram
- Institute for Stem Cell Biology and Regenerative Medicine, Department of Pathology, and Department of Chemical and Systems Biology
| | - Joanna Jackow
- Department of Dermatology, Columbia University, New York, NY 10032
- St John’s Institute of Dermatology, King’s College London, London, UK
| | - Avina Rami
- Department of Dermatology, Columbia University, New York, NY 10032
| | - Corey Hansen
- Department of Dermatology, Columbia University, New York, NY 10032
| | - Zongyou Guo
- Department of Dermatology, Columbia University, New York, NY 10032
| | - Sadhana Gaddam
- Program in Epithelial Biology and Department of Dermatology
| | | | - Lingjie Li
- Program in Epithelial Biology and Department of Dermatology
| | - Amber Cramer
- Program in Epithelial Biology and Department of Dermatology
| | - Kevin R. Roy
- Department of Genetics and Stanford Genome Technology Center, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Thuylinh Michelle Nguyen
- Department of Genetics and Stanford Genome Technology Center, Stanford University School of Medicine, Stanford, CA 94305, USA
| | | | - Patrick S. McGrath
- Department of Dermatology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Anna Bruckner
- Department of Dermatology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Ganna Bilousova
- Department of Dermatology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Dennis Roop
- Department of Dermatology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, Colorado, USA
| | - Irene Bailey
- Program in Epithelial Biology and Department of Dermatology
- Center for Definitive and Curative Medicine
| | - Jean Y. Tang
- Program in Epithelial Biology and Department of Dermatology
- Center for Definitive and Curative Medicine
| | | | - Lars M. Steinmetz
- Department of Genetics and Stanford Genome Technology Center, Stanford University School of Medicine, Stanford, CA 94305, USA
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, 69117 Heidelberg, Germany
| | - Marius Wernig
- Institute for Stem Cell Biology and Regenerative Medicine, Department of Pathology, and Department of Chemical and Systems Biology
| | - Anthony E. Oro
- Program in Epithelial Biology and Department of Dermatology
- Center for Definitive and Curative Medicine
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Roy KR, Gabunilas J, Neutel D, Ai M, Samson J, Lyu G, Chanfreau GF. Spliceosomal mutations decouple 3' splice site fidelity from cellular fitness. bioRxiv 2023:2023.01.12.523824. [PMID: 36711521 PMCID: PMC9882110 DOI: 10.1101/2023.01.12.523824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The fidelity of splice site selection is thought to be critical for proper gene expression and cellular fitness. In particular, proper recognition of 3'-splice site (3'SS) sequences by the spliceosome is a daunting task considering the low complexity of the 3'SS consensus sequence YAG. Here we show that inactivating the near-essential splicing factor Prp18p results in a global activation of alternative 3'SS, many of which harbor sequences that highly diverge from the YAG consensus, including some highly unusual non-AG 3'SS. We show that the role of Prp18p in 3'SS fidelity is promoted by physical interactions with the essential splicing factors Slu7p and Prp8p and synergized by the proofreading activity of the Prp22p helicase. Strikingly, structure-guided point mutations that disrupt Prp18p-Slu7p and Prp18p-Prp8p interactions mimic the loss of 3'SS fidelity without any impact on cellular growth, suggesting that accumulation of incorrectly spliced transcripts does not have a major deleterious effect on cellular viability. These results show that spliceosomes exhibit remarkably relaxed fidelity in the absence of Prp18p, and that new 3'SS sampling can be achieved genome-wide without a major negative impact on cellular fitness, a feature that could be used during evolution to explore new productive alternative splice sites.
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Matsui T, Mullis MN, Roy KR, Hale JJ, Schell R, Levy SF, Ehrenreich IM. The interplay of additivity, dominance, and epistasis on fitness in a diploid yeast cross. Nat Commun 2022; 13:1463. [PMID: 35304450 PMCID: PMC8933436 DOI: 10.1038/s41467-022-29111-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 02/22/2022] [Indexed: 12/27/2022] Open
Abstract
In diploid species, genetic loci can show additive, dominance, and epistatic effects. To characterize the contributions of these different types of genetic effects to heritable traits, we use a double barcoding system to generate and phenotype a panel of ~200,000 diploid yeast strains that can be partitioned into hundreds of interrelated families. This experiment enables the detection of thousands of epistatic loci, many whose effects vary across families. Here, we show traits are largely specified by a small number of hub loci with major additive and dominance effects, and pervasive epistasis. Genetic background commonly influences both the additive and dominance effects of loci, with multiple modifiers typically involved. The most prominent dominance modifier in our data is the mating locus, which has no effect on its own. Our findings show that the interplay between additivity, dominance, and epistasis underlies a complex genotype-to-phenotype map in diploids.
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Affiliation(s)
- Takeshi Matsui
- Joint Initiative for Metrology in Biology, Stanford, CA, 94305, USA
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Martin N Mullis
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
- Twist Bioscience, 681 Gateway Blvd, South San Francisco, CA, 94080, USA
| | - Kevin R Roy
- Joint Initiative for Metrology in Biology, Stanford, CA, 94305, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, 94305, USA
- Stanford Genome Technology Center, Stanford University, Palo Alto, CA, 94304, USA
| | - Joseph J Hale
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Rachel Schell
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Sasha F Levy
- Joint Initiative for Metrology in Biology, Stanford, CA, 94305, USA.
- SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA.
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, 94305, USA.
| | - Ian M Ehrenreich
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA.
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Sankaran SM, Smith JD, Roy KR. CRISPR-Cas9 Gene Editing in Yeast: A Molecular Biology and Bioinformatics Laboratory Module for Undergraduate and High School Students. J Microbiol Biol Educ 2021; 22:jmbe00106-21. [PMID: 34594460 PMCID: PMC8442027 DOI: 10.1128/jmbe.00106-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 04/16/2021] [Indexed: 06/13/2023]
Abstract
CRISPR-Cas9 genome editing technology is widely used in scientific research and biotechnology. As this technology becomes a staple tool in life sciences research, it is increasingly important to incorporate it into biology curricula to train future scientists. To demonstrate the molecular underpinnings and some limitations of CRISPR-based gene editing, we designed a laboratory module to accompany a discussion-based course on genome editing for college and advanced high school biology students. The laboratory module uses CRISPR-Cas9 to target and inactivate the ADE2 gene in Saccharomyces cerevisiae so as to give red colonies, employing an inexpensive yeast model system with a phenotypic readout that is easily detectable without specialized equipment. Students begin by accessing the yeast ADE2 sequence in a genome database, applying their understanding of Cas9 activity to design guide RNA (gRNA) sequences, using a CRISPR analysis tool to compare predicted on- and off-target effects of various gRNAs, and presenting and explaining their choice of an optimal gRNA to disrupt the ADE2 gene. They then conduct yeast transformations using Cas9 and preselected gRNA plasmids with or without donor templates to explore the importance of DNA repair pathways in genome editing. Lastly, they analyze the observed editing rates across different gRNAs targeting ADE2, leading to a discussion of editing efficiency. This module engages students in experimental design, provides hands-on experience with CRISPR-Cas9 gene editing and collaborative data analysis, and stimulates discussion on the uses and limitations of CRISPR-based gene editing technology.
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Affiliation(s)
- Saumya M. Sankaran
- Department of Biomedical Science, Kaiser Permanente Bernard J. Tyson School of Medicine, Pasadena, California, USA
| | - Justin D. Smith
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Kevin R. Roy
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
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9
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Roy KR, Chanfreau GF. Robust mapping of polyadenylated and non-polyadenylated RNA 3' ends at nucleotide resolution by 3'-end sequencing. Methods 2020; 176:4-13. [PMID: 31128237 PMCID: PMC6874744 DOI: 10.1016/j.ymeth.2019.05.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 04/10/2019] [Accepted: 05/20/2019] [Indexed: 10/26/2022] Open
Abstract
3'-end poly(A)+ sequencing is an efficient and economical method for global measurement of mRNA levels and alternative poly(A) site usage. A common method involves oligo(dT)19V reverse-transcription (RT)-based library preparation and high-throughput sequencing with a custom primer ending in (dT)19. While the majority of library products have the first sequenced nucleotide reflect the bona fide poly(A) site (pA), a substantial fraction of sequencing reads arise from various mis-priming events. These can result in incorrect pA site calls anywhere from several nucleotides downstream to several kilobases upstream from the bona fide pA site. While these mis-priming events can be mitigated by increasing annealing stringency (e.g. increasing temperature from 37 °C to 42 °C), they still persist at an appreciable level (∼10%) and computational methods must be used to prevent artifactual calls. Here we present a bioinformatics workflow for precise mapping of poly(A)+ 3' ends and handling of artifacts due to oligo(dT) mis-priming and sample polymorphisms. We test pA site calling with three different read mapping programs (STAR, BWA, and BBMap), and show that the way in which each handles terminal mismatches and soft clipping has a substantial impact on identifying correct pA sites, with BWA requiring the least post-processing to correct artifacts. We demonstrate the use of this pipeline for mapping pA sites in the model eukaryote S. cerevisiae, and further apply this technology to non-polyadenylated transcripts by employing in vitro polyadenylation prior to library prep (IVP-seq). As proof of principle, we show that a fraction of tRNAs harbor CCU 3' tails instead of the canonical CCA tail, and globally identify 3' ends of splicing intermediates arising from inefficiently spliced transcripts.
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Affiliation(s)
- Kevin R Roy
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095-1569, United States; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095-1570, United States
| | - Guillaume F Chanfreau
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095-1569, United States; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095-1570, United States.
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White JT, Cato T, Deramchi N, Gabunilas J, Roy KR, Wang C, Chanfreau GF, Clarke SG. Protein Methylation and Translation: Role of Lysine Modification on the Function of Yeast Elongation Factor 1A. Biochemistry 2019; 58:4997-5010. [PMID: 31738538 DOI: 10.1021/acs.biochem.9b00818] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
To date, 12 protein lysine methyltransferases that modify translational elongation factors and ribosomal proteins (Efm1-7 and Rkm 1-5) have been identified in the yeast Saccharomyces cerevisiae. Of these 12, five (Efm1 and Efm4-7) appear to be specific to elongation factor 1A (EF1A), the protein responsible for bringing aminoacyl-tRNAs to the ribosome. In S. cerevisiae, the functional implications of lysine methylation in translation are mostly unknown. In this work, we assessed the physiological impact of disrupting EF1A methylation in a strain where four of the most conserved methylated lysine sites are mutated to arginine residues and in strains lacking either four or five of the Efm lysine methyltransferases specific to EF1A. We found that loss of EF1A methylation was not lethal but resulted in reduced growth rates, particularly under caffeine and rapamycin stress conditions, suggesting EF1A interacts with the TORC1 pathway, as well as altered sensitivities to ribosomal inhibitors. We also detected reduced cellular levels of the EF1A protein, which surprisingly was not reflected in its stability in vivo. We present evidence that these Efm methyltransferases appear to be largely devoted to the modification of EF1A, finding no evidence of the methylation of other substrates in the yeast cell. This work starts to illuminate why one protein can need five different methyltransferases for its functions and highlights the resilience of yeast to alterations in their posttranslational modifications.
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Affiliation(s)
- Jonelle T White
- Department of Chemistry and Biochemistry and Molecular Biology Institute , University of California, Los Angeles , Los Angeles , California 90095 , United States
| | - Tieranee Cato
- Department of Chemistry and Biochemistry and Molecular Biology Institute , University of California, Los Angeles , Los Angeles , California 90095 , United States
| | - Neil Deramchi
- Department of Chemistry and Biochemistry and Molecular Biology Institute , University of California, Los Angeles , Los Angeles , California 90095 , United States
| | - Jason Gabunilas
- Department of Chemistry and Biochemistry and Molecular Biology Institute , University of California, Los Angeles , Los Angeles , California 90095 , United States
| | - Kevin R Roy
- Department of Chemistry and Biochemistry and Molecular Biology Institute , University of California, Los Angeles , Los Angeles , California 90095 , United States
| | - Charles Wang
- Department of Chemistry and Biochemistry and Molecular Biology Institute , University of California, Los Angeles , Los Angeles , California 90095 , United States
| | - Guillaume F Chanfreau
- Department of Chemistry and Biochemistry and Molecular Biology Institute , University of California, Los Angeles , Los Angeles , California 90095 , United States
| | - Steven G Clarke
- Department of Chemistry and Biochemistry and Molecular Biology Institute , University of California, Los Angeles , Los Angeles , California 90095 , United States
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11
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Zheng H, Ji Z, Roy KR, Gao M, Pan Y, Cai X, Wang L, Li W, Chang CH, Kaweeteerawat C, Chen C, Xia T, Zhao Y, Li R. Engineered Graphene Oxide Nanocomposite Capable of Preventing the Evolution of Antimicrobial Resistance. ACS Nano 2019; 13:11488-11499. [PMID: 31566947 DOI: 10.1021/acsnano.9b04970] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Antimicrobial resistance (AMR) is spreading worldwide and keeps evolving to adapt to antibiotics, causing increasing threats in clinics, which necessitates the exploration of antimicrobial agents for not only killing of resistant cells but also prevention of AMR progression. However, so far, there has been no effective approach. Herein, we designed lanthanum hydroxide and graphene oxide nanocomposites (La@GO) to confer a synergistic bactericidal effect in all tested resistant strains. More importantly, long-term exposure of E. coli (AMR) to subminimum inhibitory concentrations of La@GO does not trigger detectable secondary resistance, while conventional antibiotics and silver nanoparticles lead to a 16- to 64-fold increase in tolerance. The inability of E. coli to evolve resistance to La@GO is likely due to a distinctive extracellular multitarget invasion killing mechanism involving lipid dephosphorylation, lipid peroxidation, and peptidoglycan disruption. Overall, our results highlight La@GO nanocomposites as a promising solution to combating resistant bacteria without inducing the evolution of AMR.
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Affiliation(s)
- Huizhen Zheng
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions , Soochow University , Suzhou , 215123 , Jiangsu , China
| | - Zhaoxia Ji
- Division of Nanomedicine, Department of Medicine, California NanoSystems Institute , University of California , Los Angeles , California 90095 , United States
- Living Proof, Inc. , Cambridge , Massachusetts 02142 , United States
| | - Kevin R Roy
- Department of Genetics, School of Medicine , Stanford University , Palo Alto , California 94304 , United States
| | - Meng Gao
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions , Soochow University , Suzhou , 215123 , Jiangsu , China
| | - Yanxia Pan
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions , Soochow University , Suzhou , 215123 , Jiangsu , China
| | - Xiaoming Cai
- School of Public Health, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases , Soochow University , Suzhou , 215123 , Jiangsu , China
| | - Liming Wang
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety , Institute of High Energy Physics, Chinese Academy of Sciences (CAS) , Beijing , 100049 , China
| | - Wei Li
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions , Soochow University , Suzhou , 215123 , Jiangsu , China
| | - Chong Hyun Chang
- Division of Nanomedicine, Department of Medicine, California NanoSystems Institute , University of California , Los Angeles , California 90095 , United States
| | - Chitrada Kaweeteerawat
- National Nanotechnology Center (NANOTEC), NSTDA Characterization and Testing Center (NCTC), National Science and Technology Development Agency (NSTDA) , Klong Nueng , 12120 , Thailand
| | - Chunying Chen
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety & CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology of China, Chinese Academy of Sciences (CAS) , Beijing , 100190 , China
| | - Tian Xia
- Division of Nanomedicine, Department of Medicine, California NanoSystems Institute , University of California , Los Angeles , California 90095 , United States
| | - Yuliang Zhao
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety & CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology of China, Chinese Academy of Sciences (CAS) , Beijing , 100190 , China
| | - Ruibin Li
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions , Soochow University , Suzhou , 215123 , Jiangsu , China
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12
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Roy KR, Smith JD, Vonesch SC, Lin G, Tu CS, Lederer AR, Chu A, Suresh S, Nguyen M, Horecka J, Tripathi A, Burnett WT, Morgan MA, Schulz J, Orsley KM, Wei W, Aiyar RS, Davis RW, Bankaitis VA, Haber JE, Salit ML, St Onge RP, Steinmetz LM. Multiplexed precision genome editing with trackable genomic barcodes in yeast. Nat Biotechnol 2018; 36:512-520. [PMID: 29734294 PMCID: PMC5990450 DOI: 10.1038/nbt.4137] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Accepted: 03/12/2018] [Indexed: 12/26/2022]
Abstract
Our understanding of how genotype controls phenotype is limited by the scale at which we can precisely alter the genome and assess the phenotypic consequences of each perturbation. Here we describe a CRISPR-Cas9-based method for multiplexed accurate genome editing with short, trackable, integrated cellular barcodes (MAGESTIC) in Saccharomyces cerevisiae. MAGESTIC uses array-synthesized guide-donor oligos for plasmid-based high-throughput editing and features genomic barcode integration to prevent plasmid barcode loss and to enable robust phenotyping. We demonstrate that editing efficiency can be increased more than fivefold by recruiting donor DNA to the site of breaks using the LexA-Fkh1p fusion protein. We performed saturation editing of the essential gene SEC14 and identified amino acids critical for chemical inhibition of lipid signaling. We also constructed thousands of natural genetic variants, characterized guide mismatch tolerance at the genome scale, and ascertained that cryptic Pol III termination elements substantially reduce guide efficacy. MAGESTIC will be broadly useful to uncover the genetic basis of phenotypes in yeast.
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Affiliation(s)
- Kevin R. Roy
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Genome-Scale Measurements Group, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland, USA
- Joint Initiative for Metrology in Biology, Stanford, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Justin D. Smith
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Sibylle C. Vonesch
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
| | - Gen Lin
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
| | - Chelsea Szu Tu
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
| | - Alex R. Lederer
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
| | - Angela Chu
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Biochemistry, Stanford University School of Medicine, Stanford, California, USA
| | - Sundari Suresh
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Biochemistry, Stanford University School of Medicine, Stanford, California, USA
| | - Michelle Nguyen
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Joe Horecka
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Biochemistry, Stanford University School of Medicine, Stanford, California, USA
| | - Ashutosh Tripathi
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
| | - Wallace T. Burnett
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Maddison A. Morgan
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Julia Schulz
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Kevin M. Orsley
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Wu Wei
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Raeka S. Aiyar
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
| | - Ronald W. Davis
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
- Department of Biochemistry, Stanford University School of Medicine, Stanford, California, USA
| | - Vytas A. Bankaitis
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA
- Department of Chemistry, Texas A&M University, College Station, Texas, USA
| | - James E. Haber
- Rosenstiel Basic Medical Sciences Research Center and Department of Biology, Brandeis University, Waltham, Massachusetts, USA
| | - Marc L. Salit
- Genome-Scale Measurements Group, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland, USA
- Joint Initiative for Metrology in Biology, Stanford, California, USA
| | - Robert P. St Onge
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Department of Biochemistry, Stanford University School of Medicine, Stanford, California, USA
| | - Lars M. Steinmetz
- Stanford Genome Technology Center, Stanford University, Palo Alto, California, USA
- Joint Initiative for Metrology in Biology, Stanford, California, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
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13
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Kaweeteerawat C, Chang CH, Roy KR, Liu R, Li R, Toso D, Fischer H, Ivask A, Ji Z, Zink JI, Zhou ZH, Chanfreau GF, Telesca D, Cohen Y, Ann Holden P, Nel AE, Godwin HA. Cu Nanoparticles Have Different Impacts in Escherichia coli and Lactobacillus brevis than Their Microsized and Ionic Analogues. ACS Nano 2015; 9:7215-25. [PMID: 26168153 PMCID: PMC5698005 DOI: 10.1021/acsnano.5b02021] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Copper formulations have been used for decades for antimicrobial and antifouling applications. With the development of nanoformulations of copper that are more effective than their ionic and microsized analogues, a key regulatory question is whether these materials should be treated as new or existing materials. To address this issue, here we compare the magnitude and mechanisms of toxicity of a series of Cu species (at concentration ranging from 2 to 250 μg/mL), including nano Cu, nano CuO, nano Cu(OH)2 (CuPro and Kocide), micro Cu, micro CuO, ionic Cu(2+) (CuCl2 and CuSO4) in two species of bacteria (Escherichia coli and Lactobacillus brevis). The primary size of the particles studied ranged from 10 nm to 10 μm. Our results reveal that Cu and CuO nanoparticles (NPs) are more toxic than their microsized counterparts at the same Cu concentration, with toxicities approaching those of the ionic Cu species. Strikingly, these NPs showed distinct differences in their mode of toxicity when compared to the ionic and microsized Cu, highlighting the unique toxicity properties of materials at the nanoscale. In vitro DNA damage assays reveal that both nano Cu and microsized Cu are capable of causing complete degradation of plasmid DNA, but electron tomography results show that only nanoformulations of Cu are internalized as intact intracellular particles. These studies suggest that nano Cu at the concentration of 50 μg/mL may have unique genotoxicity in bacteria compared to ionic and microsized Cu.
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Affiliation(s)
- Chitrada Kaweeteerawat
- University of California Center for Environmental Implications of Nanotechnology, University of California, Los Angeles, California 90095, United States
- California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
- Molecular Toxicology Interdepartmental Degree Program, University of California, Los Angeles, California 90095, United States
- Department of Environmental Health Sciences, Fielding School of Public Health, University of California, Los Angeles, California 90095, United States
| | - Chong Hyun Chang
- University of California Center for Environmental Implications of Nanotechnology, University of California, Los Angeles, California 90095, United States
- California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
| | - Kevin R. Roy
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California, Los Angeles, California 90095, United States
| | - Rong Liu
- University of California Center for Environmental Implications of Nanotechnology, University of California, Los Angeles, California 90095, United States
- California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
- Institute of the Environment and Sustainability, University of California, Los Angeles, California 90039, United States
| | - Ruibin Li
- University of California Center for Environmental Implications of Nanotechnology, University of California, Los Angeles, California 90095, United States
- California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
| | - Daniel Toso
- Biomedical Engineering Interdepartmental Program, University of California, Los Angeles, California 90095, United States
| | - Heidi Fischer
- Department of Biostatistics, Fielding School of Public Health, University of California, Los Angeles (UCLA), Los Angeles, California 90095, United States
| | - Angela Ivask
- University of California Center for Environmental Implications of Nanotechnology, University of California, Los Angeles, California 90095, United States
- California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
- Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Tallinn, 12618, Estonia
| | - Zhaoxia Ji
- University of California Center for Environmental Implications of Nanotechnology, University of California, Los Angeles, California 90095, United States
- California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
| | - Jeffrey I. Zink
- University of California Center for Environmental Implications of Nanotechnology, University of California, Los Angeles, California 90095, United States
- California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Z. Hong Zhou
- California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California 90095, United States
| | - Guillaume Francois Chanfreau
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California, Los Angeles, California 90095, United States
| | - Donatello Telesca
- University of California Center for Environmental Implications of Nanotechnology, University of California, Los Angeles, California 90095, United States
- California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
- Department of Biostatistics, Fielding School of Public Health, University of California, Los Angeles (UCLA), Los Angeles, California 90095, United States
| | - Yoram Cohen
- University of California Center for Environmental Implications of Nanotechnology, University of California, Los Angeles, California 90095, United States
- California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
- Institute of the Environment and Sustainability, University of California, Los Angeles, California 90039, United States
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, United States
| | - Patricia Ann Holden
- University of California Center for Environmental Implications of Nanotechnology, University of California, Los Angeles, California 90095, United States
- Bren School of Environmental Science and Management, University of California, and Earth Research Institute, Santa Barbara, California, 93106, United States
| | - Andre E. Nel
- University of California Center for Environmental Implications of Nanotechnology, University of California, Los Angeles, California 90095, United States
- California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
- Division of NanoMedicine, Department of Medicine, University of California, Los Angeles, California 90095, United States
| | - Hilary A. Godwin
- University of California Center for Environmental Implications of Nanotechnology, University of California, Los Angeles, California 90095, United States
- California NanoSystems Institute, University of California, Los Angeles, California 90095, United States
- Molecular Toxicology Interdepartmental Degree Program, University of California, Los Angeles, California 90095, United States
- Department of Environmental Health Sciences, Fielding School of Public Health, University of California, Los Angeles, California 90095, United States
- Institute of the Environment and Sustainability, University of California, Los Angeles, California 90039, United States
- Corresponding author: mailing address: Fielding School of Public Health; Department of Environmental Health Sciences; 66-062B CHS; BOX 951772; Los Angeles, CA 90095, UNITED STATES phone: (310) 794-9112; fax: (310) 794-2106
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14
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Sathyasaikumar KV, Swapna I, Reddy PVB, Murthy CRK, Roy KR, Dutta Gupta A, Senthilkumaran B, Reddanna P. Co-administration of C-Phycocyanin ameliorates thioacetamide-induced hepatic encephalopathy in Wistar rats. J Neurol Sci 2006; 252:67-75. [PMID: 17169376 DOI: 10.1016/j.jns.2006.10.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2006] [Revised: 09/19/2006] [Accepted: 10/10/2006] [Indexed: 12/21/2022]
Abstract
Fulminant hepatic failure (FHF) is a condition with a sudden onset of necrosis followed by degeneration of hepatocytes, without any previously established liver disease, generally occurring within hours or days. FHF is associated with a wide spectrum of neuropsychiatric alterations ranging from stupor to coma, culminating in death. In the present study FHF was induced in rats by the administration of thioacetamide (TAA). Oxidative stress is thought to play a prominent role in the pathophysiology of cerebral changes during FHF leading to the assumption that antioxidants might offer protection. Hence, in the present study the protective effect of C-Phycocyanin (C-PC), a natural antioxidant, was evaluated on TAA-induced tissue damage. C-Phycocyanin was administered intraperitoneally twice at 24 h interval (50 mg/kg body weight) along with the hepatotoxin TAA (300 mg/kg body weight). The animals were sacrificed 18 h after the second injection of TAA treatment and various biochemical parameters were analysed in liver, serum and brain tissues. These studies revealed significant prevention of TAA-induced liver damage by C-PC, as evidenced by a) increase in survival rate; b) the prevention of leakage of liver enzymes (AAT and AST) and ammonia into serum; c) increase in prothrombin time and d) liver histopathology. Ultrastructural studies of astrocytes of different regions of brain clearly showed a decrease in edema after C-PC treatment. TAA-induced histopathological lesions in different regions of the brain namely cerebral cortex, cerebellum and pons medulla were significantly reduced by the co-administration of C-PC with TAA. Further C-PC treatment resulted in a) decrease in the levels of tryptophan and markers of lipid peroxidation and b) elevation in the activity levels of catalase, glutathione peroxidase in different regions of brain. These studies reveal the potential of C-PC in ameliorating TAA-induced hepatic encephalopathy by improving antioxidant defenses.
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Affiliation(s)
- K V Sathyasaikumar
- Department of Animal Sciences, School of Life Sciences, University of Hyderabad, Hyderabad-500 046, India
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