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Bercu JP, Zhang S, Sobol Z, Escobar PA, Van P, Schuler M. Comparison of the transgenic rodent mutation assay, error corrected next generation duplex sequencing, and the alkaline comet assay to detect dose-related mutations following exposure to N-nitrosodiethylamine. Mutat Res Genet Toxicol Environ Mutagen 2023; 891:503685. [PMID: 37770142 DOI: 10.1016/j.mrgentox.2023.503685] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 08/17/2023] [Accepted: 08/23/2023] [Indexed: 10/03/2023]
Abstract
N-Nitrosodiethylamine (NDEA), a well-studied N-nitrosamine, was tested in rats to compare the dose-response relationship of three genotoxicity endpoints. Mutant / mutation frequencies were determined using the transgenic rodent (TGR) gene mutation assay and error corrected next generation sequencing (ecNGS) (i.e., duplex sequencing (DS)), and genetic damage was detected by the alkaline comet assay. Big Blue® (cII Locus) animals (n = 6 per dose group) were administered doses of 0.001, 0.01, 0.1, 1, 3 mg/kg/day NDEA by oral gavage. Samples were collected for cII mutation and DS analyses following 28-days of exposure and 3 days recovery. In a separate study, male Sprague-Dawley (SD) rats (n = 6 per dose group) were administered the same doses by oral gavage for two consecutive days and then samples collected for the alkaline comet assay. A dose-related increase in mutant / mutation frequencies of the liver but not duodenum was observed using the TGR assay and DS with DS resulting in a slightly more sensitive response, with a lower benchmark dose (BMD). In addition, a dose-related increase in percent tail DNA was observed in the liver using the alkaline comet assay. Therefore, DS and comet assays showed good utility for hazard identification and dose-response analysis of a representative N-nitrosamine comparable to the TGR gene mutation assay.
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Affiliation(s)
- Joel P Bercu
- Gilead Sciences, Inc., Nonclinical Safety and Pathobiology (NSP), Foster City, CA 94404, USA.
| | - Shaofei Zhang
- Pfizer Research, Development, and Medical, Groton, CT, USA.
| | | | | | - Phu Van
- TwinStrand Biosciences, Inc., Seattle, WA, USA
| | - Maik Schuler
- Pfizer Research, Development, and Medical, Groton, CT, USA
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Dodge AE, LeBlanc DPM, Zhou G, Williams A, Meier MJ, Van P, Lo FY, Valentine Iii CC, Salk JJ, Yauk CL, Marchetti F. Duplex sequencing provides detailed characterization of mutation frequencies and spectra in the bone marrow of MutaMouse males exposed to procarbazine hydrochloride. Arch Toxicol 2023; 97:2245-2259. [PMID: 37341741 PMCID: PMC10322784 DOI: 10.1007/s00204-023-03527-y] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 05/17/2023] [Indexed: 06/22/2023]
Abstract
Mutagenicity testing is an essential component of health safety assessment. Duplex Sequencing (DS), an emerging high-accuracy DNA sequencing technology, may provide substantial advantages over conventional mutagenicity assays. DS could be used to eliminate reliance on standalone reporter assays and provide mechanistic information alongside mutation frequency (MF) data. However, the performance of DS must be thoroughly assessed before it can be routinely implemented for standard testing. We used DS to study spontaneous and procarbazine (PRC)-induced mutations in the bone marrow (BM) of MutaMouse males across a panel of 20 diverse genomic targets. Mice were exposed to 0, 6.25, 12.5, or 25 mg/kg-bw/day for 28 days by oral gavage and BM sampled 42 days post-exposure. Results were compared with those obtained using the conventional lacZ viral plaque assay on the same samples. DS detected significant increases in mutation frequencies and changes to mutation spectra at all PRC doses. Low intra-group variability within DS samples allowed for detection of increases at lower doses than the lacZ assay. While the lacZ assay initially yielded a higher fold-change in mutant frequency than DS, inclusion of clonal mutations in DS mutation frequencies reduced this discrepancy. Power analyses suggested that three animals per dose group and 500 million duplex base pairs per sample is sufficient to detect a 1.5-fold increase in mutations with > 80% power. Overall, we demonstrate several advantages of DS over classical mutagenicity assays and provide data to support efforts to identify optimal study designs for the application of DS as a regulatory test.
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Affiliation(s)
- Annette E Dodge
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Danielle P M LeBlanc
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Gu Zhou
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Andrew Williams
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Matthew J Meier
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Phu Van
- TwinStrand Biosciences Inc., Seattle, Washington, USA
| | - Fang Yin Lo
- TwinStrand Biosciences Inc., Seattle, Washington, USA
| | | | - Jesse J Salk
- TwinStrand Biosciences Inc., Seattle, Washington, USA
| | - Carole L Yauk
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada.
- Department of Biology, Carleton University, Ottawa, Ontario, Canada.
| | - Francesco Marchetti
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada.
- Department of Biology, Carleton University, Ottawa, Ontario, Canada.
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Cho E, Swartz CD, Williams A, V Rivas M, Recio L, Witt KL, Schmidt EK, Yaplee J, Smith TH, Van P, Lo FY, Valentine CC, Salk JJ, Marchetti F, Smith-Roe SL, Yauk CL. Error-corrected duplex sequencing enables direct detection and quantification of mutations in human TK6 cells with strong inter-laboratory consistency. Mutat Res Genet Toxicol Environ Mutagen 2023; 889:503649. [PMID: 37491114 PMCID: PMC10395007 DOI: 10.1016/j.mrgentox.2023.503649] [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] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 05/12/2023] [Accepted: 05/18/2023] [Indexed: 07/27/2023]
Abstract
Error-corrected duplex sequencing (DS) enables direct quantification of low-frequency mutations and offers tremendous potential for chemical mutagenicity assessment. We investigated the utility of DS to quantify induced mutation frequency (MF) and spectrum in human lymphoblastoid TK6 cells exposed to a prototypical DNA alkylating agent, N-ethyl-N-nitrosourea (ENU). Furthermore, we explored appropriate experimental parameters for this application, and assessed inter-laboratory reproducibility. In two independent experiments in two laboratories, TK6 cells were exposed to ENU (25-200 µM) and DNA was sequenced 48, 72, and 96 h post-exposure. A DS mutagenicity panel targeting twenty 2.4-kb regions distributed across the genome was used to sample diverse, genome-representative sequence contexts. A significant increase in MF that was unaffected by time was observed in both laboratories. Concentration-response in the MF from the two laboratories was strongly positively correlated (r = 0.97). C:G>T:A, T:A>C:G, T:A>A:T, and T:A>G:C mutations increased in consistent, concentration-dependent manners in both laboratories, with high proportions of C:G>T:A at all time points. The consistent results across the three time points suggest that 48 h may be sufficient for mutation analysis post-exposure. The target sites responded similarly between the two laboratories and revealed a higher average MF in intergenic regions. These results, demonstrating remarkable reproducibility across time and laboratory for both MF and spectrum, support the high value of DS for characterizing chemical mutagenicity in both research and regulatory evaluation.
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Affiliation(s)
- Eunnara Cho
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada; Department of Biology, Carleton University, Ottawa, ON, Canada
| | | | - Andrew Williams
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | | | - Leslie Recio
- Inotiv-RTP, Research Triangle Park, NC, USA; Scitovation, Research Triangle Park, NC, USA
| | - Kristine L Witt
- Division of Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | | | | | - Phu Van
- TwinStrand Biosciences, Inc., Seattle, WA, USA
| | - Fang Yin Lo
- TwinStrand Biosciences, Inc., Seattle, WA, USA
| | | | | | - Francesco Marchetti
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada; Department of Biology, Carleton University, Ottawa, ON, Canada
| | - Stephanie L Smith-Roe
- Division of Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.
| | - Carole L Yauk
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada; Department of Biology, Carleton University, Ottawa, ON, Canada; Department of Biology, University of Ottawa, Ottawa, ON, Canada.
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Moncunill G, Carnes J, Chad Young W, Carpp L, De Rosa S, Campo JJ, Nhabomba A, Mpina M, Jairoce C, Finak G, Haas P, Muriel C, Van P, Sanz H, Dutta S, Mordmüller B, Agnandji ST, Díez-Padrisa N, Williams NA, Aponte JJ, Valim C, Neafsey DE, Daubenberger C, McElrath MJ, Dobaño C, Stuart K, Gottardo R. Transcriptional correlates of malaria in RTS,S/AS01-vaccinated African children: a matched case–control study. eLife 2022; 11:70393. [PMID: 35060479 PMCID: PMC8782572 DOI: 10.7554/elife.70393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 12/20/2021] [Indexed: 12/24/2022] Open
Abstract
Background: In a phase 3 trial in African infants and children, the RTS,S/AS01 vaccine (GSK) showed moderate efficacy against clinical malaria. We sought to further understand RTS,S/AS01-induced immune responses associated with vaccine protection. Methods: Applying the blood transcriptional module (BTM) framework, we characterized the transcriptomic response to RTS,S/AS01 vaccination in antigen-stimulated (and vehicle control) peripheral blood mononuclear cells sampled from a subset of trial participants at baseline and month 3 (1-month post-third dose). Using a matched case–control study design, we evaluated which of these ‘RTS,S/AS01 signature BTMs’ associated with malaria case status in RTS,S/AS01 vaccinees. Antigen-specific T-cell responses were analyzed by flow cytometry. We also performed a cross-study correlates analysis where we assessed the generalizability of our findings across three controlled human malaria infection studies of healthy, malaria-naive adult RTS,S/AS01 recipients. Results: RTS,S/AS01 vaccination was associated with downregulation of B-cell and monocyte-related BTMs and upregulation of T-cell-related BTMs, as well as higher month 3 (vs. baseline) circumsporozoite protein-specific CD4+ T-cell responses. There were few RTS,S/AS01-associated BTMs whose month 3 levels correlated with malaria risk. In contrast, baseline levels of BTMs associated with dendritic cells and with monocytes (among others) correlated with malaria risk. The baseline dendritic cell- and monocyte-related BTM correlations with malaria risk appeared to generalize to healthy, malaria-naive adults. Conclusions: A prevaccination transcriptomic signature associates with malaria in RTS,S/AS01-vaccinated African children, and elements of this signature may be broadly generalizable. The consistent presence of monocyte-related modules suggests that certain monocyte subsets may inhibit protective RTS,S/AS01-induced responses. Funding: Funding was obtained from the NIH-NIAID (R01AI095789), NIH-NIAID (U19AI128914), PATH Malaria Vaccine Initiative (MVI), and Ministerio de Economía y Competitividad (Instituto de Salud Carlos III, PI11/00423 and PI14/01422). The RNA-seq project has been funded in whole or in part with Federal funds from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Department of Health and Human Services, under grant number U19AI110818 to the Broad Institute. This study was also supported by the Vaccine Statistical Support (Bill and Melinda Gates Foundation award INV-008576/OPP1154739 to R.G.). C.D. was the recipient of a Ramon y Cajal Contract from the Ministerio de Economía y Competitividad (RYC-2008-02631). G.M. was the recipient of a Sara Borrell–ISCIII fellowship (CD010/00156) and work was performed with the support of Department of Health, Catalan Government grant (SLT006/17/00109). This research is part of the ISGlobal’s Program on the Molecular Mechanisms of Malaria which is partially supported by the Fundación Ramón Areces and we acknowledge support from the Spanish Ministry of Science and Innovation through the ‘Centro de Excelencia Severo Ochoa 2019–2023’ Program (CEX2018-000806-S), and support from the Generalitat de Catalunya through the CERCA Program.
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Affiliation(s)
- Gemma Moncunill
- ISGlobal, Hospital Clínic - Universitat de Barcelona
- CIBER de Enfermedades Infecciosas
| | - Jason Carnes
- Center for Global Infectious Disease Research, Seattle Children's Research Institute
| | - William Chad Young
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center
| | - Lindsay Carpp
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center
| | - Stephen De Rosa
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center
| | | | - Augusto Nhabomba
- Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça
| | | | - Chenjerai Jairoce
- Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça
| | - Greg Finak
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center
| | - Paige Haas
- Center for Global Infectious Disease Research, Seattle Children's Research Institute
| | - Carl Muriel
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center
| | - Phu Van
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center
| | - Héctor Sanz
- ISGlobal, Hospital Clínic - Universitat de Barcelona
| | | | - Benjamin Mordmüller
- CIBER de Enfermedades Infecciosas
- Institute of Tropical Medicine and German Center for Infection Research
| | - Selidji T Agnandji
- Institute of Tropical Medicine and German Center for Infection Research
- Centre de Recherches Médicales de Lambaréné (CERMEL), BP 242
| | | | | | - John J Aponte
- ISGlobal, Hospital Clínic - Universitat de Barcelona
| | - Clarissa Valim
- Department of Global Health, Boston University School of Public Health
| | - Daniel E Neafsey
- Broad Institute of Massachusetts Institute of Technology and Harvard
- Harvard T.H. Chan School of Public Health
| | | | - M Juliana McElrath
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center
- Departments of Laboratory Medicine and Medicine, University of Washington
| | - Carlota Dobaño
- ISGlobal, Hospital Clínic - Universitat de Barcelona
- CIBER de Enfermedades Infecciosas
| | - Ken Stuart
- Center for Global Infectious Disease Research, Seattle Children's Research Institute
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center
- Department of Pediatrics, University of Washington
- Department of Global Health, University of Washington
| | - Raphael Gottardo
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center
- University of Lausanne and Centre Hospitalier Universitaire Vaudois
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Van P, Jiang W, Gottardo R, Finak G. ggCyto: next generation open-source visualization software for cytometry. Bioinformatics 2019; 34:3951-3953. [PMID: 29868771 PMCID: PMC6223365 DOI: 10.1093/bioinformatics/bty441] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 05/25/2018] [Indexed: 11/13/2022] Open
Abstract
Motivation Open source software for computational cytometry has gained in popularity over the past few years. Efforts such as FlowCAP, the Lyoplate and Euroflow projects have highlighted the importance of efforts to standardize both experimental and computational aspects of cytometry data analysis. The R/BioConductor platform hosts the largest collection of open source cytometry software covering all aspects of data analysis and providing infrastructure to represent and analyze cytometry data with all relevant experimental, gating and cell population annotations enabling fully reproducible data analysis. Data visualization frameworks to support this infrastructure have lagged behind. Results ggCyto is a new open-source BioConductor software package for cytometry data visualization built on ggplot2 that enables ggplot-like functionality with the core BioConductor flow cytometry data structures. Amongst its features are the ability to transform data and axes on-the-fly using cytometry-specific transformations, plot faceting by experimental meta-data variables and partial matching of channel, marker and cell populations names to the contents of the BioConductor cytometry data structures. We demonstrate the salient features of the package using publicly available cytometry data with complete reproducible examples in a Supplementary Material. Availability and implementation https://bioconductor.org/packages/devel/bioc/html/ggcyto.html Supplementary information Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Phu Van
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Wenxin Jiang
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Raphael Gottardo
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Greg Finak
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
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Abstract
African American women experience pregnancy and infant losses at rates twice those of European American women and women of other recognized ethnic and racial groups. Health professionals, families, and friends tend to avoid discussions of these losses because grief following pregnancy or infant loss is frequently considered insignificant. Bereaved mothers whose grief is unrecognized are likely to have grief responses that are exaggerated in intensity and duration. In this article I reflect part of a larger qualitative study in which I explored the pregnancy-related experiences of 10 African American women. The purpose of this article is to describe the perceived strategies these women used to heal after pregnancy or infant loss. Individual interviews were conducted using open-ended questions. Grounded theory methodology was used to analyze the data. The healing strategies used by the participants reflect predominately inner and instinctive processes, resources, and remedies. Culturally appropriate strategies for health care interventions and research activities are offered.
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Affiliation(s)
- P Van
- University of California, San Francisco, USA.
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Van P, Papenfuss C, Muschik W. Mesoscopic dynamics of microcracks. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 2000; 62:6206-6215. [PMID: 11101951 DOI: 10.1103/physreve.62.6206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2000] [Revised: 06/28/2000] [Indexed: 05/23/2023]
Abstract
The mesoscopic concept is applied to the description of microcracks. The balance equations of the cracked continuum result in mesoscopic directional balances of mass, momentum, angular momentum, and energy. Averaging over the length of the cracks gives the corresponding orientational balances. A further averaging process leads to the macroscopic balance equations of the microcracked continua. Dynamic equations for the fabric tensors of different order are derived using a multipole moment expansion of the orientational crack distribution function. The simple example of Griffith cracks is treated. The role of physical assumptions in the microcrack representations and the different macroscopic internal variable representations of microcracks are discussed.
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Affiliation(s)
- P Van
- Department of Chemical Physics, Technical University of Budapest, Budafoki ut 8, 1521 Budapest, Hungary and Institut fur Mechanik, Institut fur Theoretische Physik, Technische Universitat Berlin, Strasse des 17. Juni, 10623 Berlin, Germany
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