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Walton RT, Qin Y, Blainey PC. CROPseq-multi: a versatile solution for multiplexed perturbation and decoding in pooled CRISPR screens. bioRxiv 2024:2024.03.17.585235. [PMID: 38558968 PMCID: PMC10979941 DOI: 10.1101/2024.03.17.585235] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Forward genetic screens seek to dissect complex biological systems by systematically perturbing genetic elements and observing the resulting phenotypes. While standard screening methodologies introduce individual perturbations, multiplexing perturbations improves the performance of single-target screens and enables combinatorial screens for the study of genetic interactions. Current tools for multiplexing perturbations are incompatible with pooled screening methodologies that require mRNA-embedded barcodes, including some microscopy and single cell sequencing approaches. Here, we report the development of CROPseq-multi, a CROPseq1-inspired lentiviral system to multiplex Streptococcus pyogenes (Sp) Cas9-based perturbations with mRNA-embedded barcodes. CROPseq-multi has equivalent per-guide activity to CROPseq and low lentiviral recombination frequencies. CROPseq-multi is compatible with enrichment screening methodologies and optical pooled screens, and is extensible to screens with single-cell sequencing readouts. For optical pooled screens, an optimized and multiplexed in situ detection protocol improves barcode detection efficiency 10-fold, enables detection of recombination events, and increases decoding efficiency 3-fold relative to CROPseq. CROPseq-multi is a widely applicable multiplexing solution for diverse SpCas9-based genetic screening approaches.
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Affiliation(s)
- Russell T. Walton
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Biological Engineering, MIT, Cambridge, MA, USA
| | - Yue Qin
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Eric and Wendy Schmidt Center, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Paul C. Blainey
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Biological Engineering, MIT, Cambridge, MA, USA
- Koch Institute for Integrative Cancer Research, MIT, Cambridge, MA, USA
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Christie KA, Guo JA, Silverstein RA, Doll RM, Mabuchi M, Stutzman HE, Lin J, Ma L, Walton RT, Pinello L, Robb GB, Kleinstiver BP. Precise DNA cleavage using CRISPR-SpRYgests. Nat Biotechnol 2023; 41:409-416. [PMID: 36203014 PMCID: PMC10023266 DOI: 10.1038/s41587-022-01492-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [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: 11/17/2021] [Accepted: 08/31/2022] [Indexed: 11/09/2022]
Abstract
Methods for in vitro DNA cleavage and molecular cloning remain unable to precisely cleave DNA directly adjacent to bases of interest. Restriction enzymes (REs) must bind specific motifs, whereas wild-type CRISPR-Cas9 or CRISPR-Cas12 nucleases require protospacer adjacent motifs (PAMs). Here we explore the utility of our previously reported near-PAMless SpCas9 variant, named SpRY, to serve as a universal DNA cleavage tool for various cloning applications. By performing SpRY DNA digests (SpRYgests) using more than 130 guide RNAs (gRNAs) sampling a wide diversity of PAMs, we discovered that SpRY is PAMless in vitro and can cleave DNA at practically any sequence, including sites refractory to cleavage with wild-type SpCas9. We illustrate the versatility and effectiveness of SpRYgests to improve the precision of several cloning workflows, including those not possible with REs or canonical CRISPR nucleases. We also optimize a rapid and simple one-pot gRNA synthesis protocol to streamline SpRYgest implementation. Together, SpRYgests can improve various DNA engineering applications that benefit from precise DNA breaks.
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Affiliation(s)
- Kathleen A Christie
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
- Department of Pathology, Harvard Medical School, Boston, MA, USA
| | - Jimmy A Guo
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
- Biological and Biomedical Sciences Program, Harvard University, Boston, MA, USA
| | - Rachel A Silverstein
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
- Biological and Biomedical Sciences Program, Harvard University, Boston, MA, USA
| | - Roman M Doll
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
- Molecular Biosciences/Cancer Biology Program, Heidelberg University and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | | | - Hannah E Stutzman
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
| | - Jiecong Lin
- Department of Pathology, Harvard Medical School, Boston, MA, USA
- Molecular Pathology Unit, Massachusetts General Hospital, Boston, MA, USA
- Center for Cancer Research, Massachusetts General Hospital Charlestown, Boston, MA, USA
| | - Linyuan Ma
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
- Department of Pathology, Harvard Medical School, Boston, MA, USA
| | - Russell T Walton
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Luca Pinello
- Department of Pathology, Harvard Medical School, Boston, MA, USA
- Molecular Pathology Unit, Massachusetts General Hospital, Boston, MA, USA
- Center for Cancer Research, Massachusetts General Hospital Charlestown, Boston, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | | | - Benjamin P Kleinstiver
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA.
- Department of Pathology, Harvard Medical School, Boston, MA, USA.
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3
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Walton RT, Singh A, Blainey PC. Pooled genetic screens with image‐based profiling. Mol Syst Biol 2022; 18:e10768. [PMID: 36366905 PMCID: PMC9650298 DOI: 10.15252/msb.202110768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 10/22/2021] [Revised: 09/12/2022] [Accepted: 09/16/2022] [Indexed: 11/13/2022] Open
Abstract
Spatial structure in biology, spanning molecular, organellular, cellular, tissue, and organismal scales, is encoded through a combination of genetic and epigenetic factors in individual cells. Microscopy remains the most direct approach to exploring the intricate spatial complexity defining biological systems and the structured dynamic responses of these systems to perturbations. Genetic screens with deep single‐cell profiling via image features or gene expression programs have the capacity to show how biological systems work in detail by cataloging many cellular phenotypes with one experimental assay. Microscopy‐based cellular profiling provides information complementary to next‐generation sequencing (NGS) profiling and has only recently become compatible with large‐scale genetic screens. Optical screening now offers the scale needed for systematic characterization and is poised for further scale‐up. We discuss how these methodologies, together with emerging technologies for genetic perturbation and microscopy‐based multiplexed molecular phenotyping, are powering new approaches to reveal genotype–phenotype relationships.
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Affiliation(s)
- Russell T Walton
- Broad Institute of MIT and Harvard Cambridge MA USA
- Department of Biological Engineering MIT Cambridge MA USA
| | - Avtar Singh
- Broad Institute of MIT and Harvard Cambridge MA USA
| | - Paul C Blainey
- Broad Institute of MIT and Harvard Cambridge MA USA
- Department of Biological Engineering MIT Cambridge MA USA
- Koch Institute for Integrative Cancer Research MIT Cambridge MA USA
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4
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Hu Y, Stilp AM, McHugh CP, Rao S, Jain D, Zheng X, Lane J, Méric de Bellefon S, Raffield LM, Chen MH, Yanek LR, Wheeler M, Yao Y, Ren C, Broome J, Moon JY, de Vries PS, Hobbs BD, Sun Q, Surendran P, Brody JA, Blackwell TW, Choquet H, Ryan K, Duggirala R, Heard-Costa N, Wang Z, Chami N, Preuss MH, Min N, Ekunwe L, Lange LA, Cushman M, Faraday N, Curran JE, Almasy L, Kundu K, Smith AV, Gabriel S, Rotter JI, Fornage M, Lloyd-Jones DM, Vasan RS, Smith NL, North KE, Boerwinkle E, Becker LC, Lewis JP, Abecasis GR, Hou L, O’Connell JR, Morrison AC, Beaty TH, Kaplan R, Correa A, Blangero J, Jorgenson E, Psaty BM, Kooperberg C, Walton RT, Kleinstiver BP, Tang H, Loos RJ, Soranzo N, Butterworth AS, Nickerson D, Rich SS, Mitchell BD, Johnson AD, Auer PL, Li Y, Mathias RA, Lettre G, Pankratz N, Laurie CC, Laurie CA, Bauer DE, Conomos MP, Reiner AP. Whole-genome sequencing association analysis of quantitative red blood cell phenotypes: The NHLBI TOPMed program. Am J Hum Genet 2021; 108:1165. [PMID: 34087167 PMCID: PMC8206380 DOI: 10.1016/j.ajhg.2021.04.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Hu Y, Stilp AM, McHugh CP, Rao S, Jain D, Zheng X, Lane J, Méric de Bellefon S, Raffield LM, Chen MH, Yanek LR, Wheeler M, Yao Y, Ren C, Broome J, Moon JY, de Vries PS, Hobbs BD, Sun Q, Surendran P, Brody JA, Blackwell TW, Choquet H, Ryan K, Duggirala R, Heard-Costa N, Wang Z, Chami N, Preuss MH, Min N, Ekunwe L, Lange LA, Cushman M, Faraday N, Curran JE, Almasy L, Kundu K, Smith AV, Gabriel S, Rotter JI, Fornage M, Lloyd-Jones DM, Vasan RS, Smith NL, North KE, Boerwinkle E, Becker LC, Lewis JP, Abecasis GR, Hou L, O'Connell JR, Morrison AC, Beaty TH, Kaplan R, Correa A, Blangero J, Jorgenson E, Psaty BM, Kooperberg C, Walton RT, Kleinstiver BP, Tang H, Loos RJF, Soranzo N, Butterworth AS, Nickerson D, Rich SS, Mitchell BD, Johnson AD, Auer PL, Li Y, Mathias RA, Lettre G, Pankratz N, Laurie CC, Laurie CA, Bauer DE, Conomos MP, Reiner AP. Whole-genome sequencing association analysis of quantitative red blood cell phenotypes: The NHLBI TOPMed program. Am J Hum Genet 2021; 108:874-893. [PMID: 33887194 DOI: 10.1016/j.ajhg.2021.04.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [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: 12/19/2020] [Accepted: 03/30/2021] [Indexed: 02/06/2023] Open
Abstract
Whole-genome sequencing (WGS), a powerful tool for detecting novel coding and non-coding disease-causing variants, has largely been applied to clinical diagnosis of inherited disorders. Here we leveraged WGS data in up to 62,653 ethnically diverse participants from the NHLBI Trans-Omics for Precision Medicine (TOPMed) program and assessed statistical association of variants with seven red blood cell (RBC) quantitative traits. We discovered 14 single variant-RBC trait associations at 12 genomic loci, which have not been reported previously. Several of the RBC trait-variant associations (RPN1, ELL2, MIDN, HBB, HBA1, PIEZO1, and G6PD) were replicated in independent GWAS datasets imputed to the TOPMed reference panel. Most of these discovered variants are rare/low frequency, and several are observed disproportionately among non-European Ancestry (African, Hispanic/Latino, or East Asian) populations. We identified a 3 bp indel p.Lys2169del (g.88717175_88717177TCT[4]) (common only in the Ashkenazi Jewish population) of PIEZO1, a gene responsible for the Mendelian red cell disorder hereditary xerocytosis (MIM: 194380), associated with higher mean corpuscular hemoglobin concentration (MCHC). In stepwise conditional analysis and in gene-based rare variant aggregated association analysis, we identified several of the variants in HBB, HBA1, TMPRSS6, and G6PD that represent the carrier state for known coding, promoter, or splice site loss-of-function variants that cause inherited RBC disorders. Finally, we applied base and nuclease editing to demonstrate that the sentinel variant rs112097551 (nearest gene RPN1) acts through a cis-regulatory element that exerts long-range control of the gene RUVBL1 which is essential for hematopoiesis. Together, these results demonstrate the utility of WGS in ethnically diverse population-based samples and gene editing for expanding knowledge of the genetic architecture of quantitative hematologic traits and suggest a continuum between complex trait and Mendelian red cell disorders.
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Affiliation(s)
- Yao Hu
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98105, USA
| | - Adrienne M Stilp
- Department of Biostatistics, University of Washington, Seattle, WA 98105, USA
| | - Caitlin P McHugh
- Department of Biostatistics, University of Washington, Seattle, WA 98105, USA
| | - Shuquan Rao
- Division of Hematology/Oncology, Boston Children's Hospital, Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Stem Cell Institute, Broad Institute, Department of Pediatrics, Harvard Medical School, Boston, MA 02215, USA
| | - Deepti Jain
- Department of Biostatistics, University of Washington, Seattle, WA 98105, USA
| | - Xiuwen Zheng
- Department of Biostatistics, University of Washington, Seattle, WA 98105, USA
| | - John Lane
- Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | | | - Laura M Raffield
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Ming-Huei Chen
- Population Sciences Branch, Division of Intramural Research, National Heart, Lung and Blood Institute, Bethesda, MD 20892, USA; National Heart Lung and Blood Institute's and Boston University's Framingham Heart Study, Framingham, MA 01701, USA
| | - Lisa R Yanek
- Division of General Internal Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Marsha Wheeler
- Department of Genome Sciences, University of Washington, Seattle, WA 98105, USA
| | - Yao Yao
- Division of Hematology/Oncology, Boston Children's Hospital, Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Stem Cell Institute, Broad Institute, Department of Pediatrics, Harvard Medical School, Boston, MA 02215, USA
| | - Chunyan Ren
- Division of Hematology/Oncology, Boston Children's Hospital, Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Stem Cell Institute, Broad Institute, Department of Pediatrics, Harvard Medical School, Boston, MA 02215, USA
| | - Jai Broome
- Department of Biostatistics, University of Washington, Seattle, WA 98105, USA
| | - Jee-Young Moon
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Paul S de Vries
- Human Genetics Center, Department of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Brian D Hobbs
- Channing Division of Network Medicine and Division of Pulmonary and Critical Care Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Quan Sun
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Praveen Surendran
- British Heart Foundation Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge CB1 8RN, UK; British Heart Foundation Centre of Research Excellence, University of Cambridge, Cambridge CB1 8RN, UK; Health Data Research UK Cambridge, Wellcome Genome Campus and University of Cambridge, Cambridge CB1 8RN, UK; Rutherford Fund Fellow, Department of Public Health and Primary Care, University of Cambridge, Cambridge CB1 8RN, UK
| | - Jennifer A Brody
- Cardiovascular Health Research Unit, Department of Medicine, University of Washington, Seattle, WA 98105, USA
| | - Thomas W Blackwell
- TOPMed Informatics Research Center, University of Michigan, Department of Biostatistics, Ann Arbor, MI 48109, USA
| | - Hélène Choquet
- Division of Research, Kaiser Permanente Northern California, Oakland, CA 94601, USA
| | - Kathleen Ryan
- Department of Medicine, Division of Endocrinology, Diabetes & Nutrition, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Ravindranath Duggirala
- Department of Human Genetics and South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, Brownsville, TX 78539, USA
| | - Nancy Heard-Costa
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA; National Heart Lung and Blood Institute's and Boston University's Framingham Heart Study, Framingham, MA 01701, USA; Department of Neurology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Zhe Wang
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Nathalie Chami
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Michael H Preuss
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Nancy Min
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Lynette Ekunwe
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - Leslie A Lange
- Division of Biomedical Informatics and Personalized Medicine, School of Medicine University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Mary Cushman
- Department of Medicine, Larner College of Medicine at the University of Vermont, Burlington, VT 05405, USA
| | - Nauder Faraday
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Joanne E Curran
- Department of Human Genetics and South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, Brownsville, TX 78539, USA
| | - Laura Almasy
- Department of Biomedical and Health Informatics, Children's Hospital of Philadelphia and Department of Genetics University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Kousik Kundu
- Department of Human Genetics, Wellcome Sanger Institute, Hinxton CB10 1SA, UK; Department of Haematology, University of Cambridge, Cambridge CB2 0PT, UK
| | - Albert V Smith
- TOPMed Informatics Research Center, University of Michigan, Department of Biostatistics, Ann Arbor, MI 48109, USA
| | | | - Jerome I Rotter
- The Institute for Translational Genomics and Population Sciences, Department of Pediatrics, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA 90502, USA
| | - Myriam Fornage
- University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | | | - Ramachandran S Vasan
- National Heart Lung and Blood Institute's and Boston University's Framingham Heart Study, Framingham, MA 01701, USA; Departments of Cardiology and Preventive Medicine, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA; Department of Biostatistics, Boston University School of Public Health, Boston, MA 02118, USA
| | - Nicholas L Smith
- Department of Epidemiology, University of Washington, Seattle, WA 98105, USA; Kaiser Permanente Washington Health Research Institute, Kaiser Permanente Washington, Seattle, WA 98105, USA; Seattle Epidemiologic Research and Information Center, Department of Veterans Affairs Office of Research and Development, Seattle, WA 98105, USA
| | - Kari E North
- Department of Epidemiology, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Eric Boerwinkle
- Human Genetics Center, Department of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Lewis C Becker
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Joshua P Lewis
- Department of Medicine, Division of Endocrinology, Diabetes & Nutrition, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Goncalo R Abecasis
- TOPMed Informatics Research Center, University of Michigan, Department of Biostatistics, Ann Arbor, MI 48109, USA
| | - Lifang Hou
- Northwestern University, Chicago, IL 60208, USA
| | - Jeffrey R O'Connell
- Department of Medicine, Division of Endocrinology, Diabetes & Nutrition, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Alanna C Morrison
- Human Genetics Center, Department of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Terri H Beaty
- School of Public Health, John Hopkins University, Baltimore, MD 21205, USA
| | - Robert Kaplan
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Adolfo Correa
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS 39216, USA
| | - John Blangero
- Department of Human Genetics and South Texas Diabetes and Obesity Institute, University of Texas Rio Grande Valley School of Medicine, Brownsville, TX 78539, USA
| | - Eric Jorgenson
- Division of Research, Kaiser Permanente Northern California, Oakland, CA 94601, USA
| | - Bruce M Psaty
- Department of Epidemiology, University of Washington, Seattle, WA 98105, USA; Kaiser Permanente Washington Health Research Institute, Kaiser Permanente Washington, Seattle, WA 98105, USA; Department of Medicine, University of Washington, Seattle, WA 98105, USA
| | - Charles Kooperberg
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98105, USA
| | - Russell T Walton
- Center for Genomic Medicine and Department of Pathology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Benjamin P Kleinstiver
- Center for Genomic Medicine and Department of Pathology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Pathology, Harvard Medical School, Boston, MA 02115, USA
| | - Hua Tang
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ruth J F Loos
- The Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Nicole Soranzo
- British Heart Foundation Centre of Research Excellence, University of Cambridge, Cambridge CB1 8RN, UK; Department of Human Genetics, Wellcome Sanger Institute, Hinxton CB10 1SA, UK; Department of Haematology, University of Cambridge, Cambridge CB2 0PT, UK; National Institute for Health Research Blood and Transplant Research Unit in Donor Health and Genomics, University of Cambridge, Cambridge CB1 8RN, UK
| | - Adam S Butterworth
- British Heart Foundation Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge CB1 8RN, UK; British Heart Foundation Centre of Research Excellence, University of Cambridge, Cambridge CB1 8RN, UK; Health Data Research UK Cambridge, Wellcome Genome Campus and University of Cambridge, Cambridge CB1 8RN, UK; National Institute for Health Research Blood and Transplant Research Unit in Donor Health and Genomics, University of Cambridge, Cambridge CB1 8RN, UK; National Institute for Health Research Cambridge Biomedical Research Centre, University of Cambridge and Cambridge University Hospitals, Cambridge CB1 8RN, UK
| | - Debbie Nickerson
- Department of Genome Sciences, University of Washington, Seattle, WA 98105, USA
| | - Stephen S Rich
- Center for Public Health Genomics, Department of Public Health Sciences, University of Virginia School of Medicine, Charlottesville, VA 22903, USA
| | - Braxton D Mitchell
- Department of Medicine, Division of Endocrinology, Diabetes & Nutrition, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Andrew D Johnson
- Population Sciences Branch, Division of Intramural Research, National Heart, Lung and Blood Institute, Bethesda, MD 20892, USA; National Heart Lung and Blood Institute's and Boston University's Framingham Heart Study, Framingham, MA 01701, USA
| | - Paul L Auer
- Zilber School of Public Health, University of Wisconsin-Milwaukee, Milwaukee, WI 53205, USA
| | - Yun Li
- Departments of Biostatistics, Genetics, Computer Science, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Rasika A Mathias
- Division of Allergy and Clinical Immunology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MA 21205, USA
| | - Guillaume Lettre
- Montreal Heart Institute, Montréal, QC H1T 1C8, Canada; Faculté de Médecine, Université de Montréal, Montréal, QC H1T 1C8, Canada
| | - Nathan Pankratz
- Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Cathy C Laurie
- Department of Biostatistics, University of Washington, Seattle, WA 98105, USA
| | - Cecelia A Laurie
- Department of Biostatistics, University of Washington, Seattle, WA 98105, USA
| | - Daniel E Bauer
- Division of Hematology/Oncology, Boston Children's Hospital, Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Stem Cell Institute, Broad Institute, Department of Pediatrics, Harvard Medical School, Boston, MA 02215, USA
| | - Matthew P Conomos
- Department of Biostatistics, University of Washington, Seattle, WA 98105, USA
| | - Alexander P Reiner
- Department of Epidemiology, University of Washington, Seattle, WA 98105, USA.
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6
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Walton RT, Hsu JY, Joung JK, Kleinstiver BP. Scalable characterization of the PAM requirements of CRISPR-Cas enzymes using HT-PAMDA. Nat Protoc 2021; 16:1511-1547. [PMID: 33547443 PMCID: PMC8063866 DOI: 10.1038/s41596-020-00465-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [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: 08/26/2020] [Accepted: 11/18/2020] [Indexed: 12/23/2022]
Abstract
The continued expansion of the genome-editing toolbox necessitates methods to characterize important properties of CRISPR-Cas enzymes. One such property is the requirement for Cas proteins to recognize a protospacer-adjacent motif (PAM) in DNA target sites. The high-throughput PAM determination assay (HT-PAMDA) is a method that enables scalable characterization of the PAM preferences of different Cas proteins. Here, we provide a step-by-step protocol for the method, discuss experimental design considerations, and highlight how the method can be used to profile naturally occurring CRISPR-Cas9 enzymes, engineered derivatives with improved properties, orthologs of different classes (e.g., Cas12a), and even different platforms (e.g., base editors). A distinguishing feature of HT-PAMDA is that the enzymes are expressed in a cell type or organism of interest (e.g., mammalian cells), permitting scalable characterization and comparison of hundreds of enzymes in a relevant setting. HT-PAMDA does not require specialized equipment or expertise and is cost effective for multiplexed characterization of many enzymes. The protocol enables comprehensive PAM characterization of dozens or hundreds of Cas enzymes in parallel in <2 weeks.
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Affiliation(s)
- Russell T Walton
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Jonathan Y Hsu
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Molecular Pathology Unit, Center for Cancer Research and Center for Computational and Integrative Biology, Massachusetts General Hospital, Charlestown, MA, USA
- Department of Pathology, Harvard Medical School, Boston, MA, USA
| | - J Keith Joung
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
- Molecular Pathology Unit, Center for Cancer Research and Center for Computational and Integrative Biology, Massachusetts General Hospital, Charlestown, MA, USA
- Department of Pathology, Harvard Medical School, Boston, MA, USA
| | - Benjamin P Kleinstiver
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA.
- Department of Pathology, Harvard Medical School, Boston, MA, USA.
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7
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Walton RT, Christie KA, Whittaker MN, Kleinstiver BP. Unconstrained genome targeting with near-PAMless engineered CRISPR-Cas9 variants. Science 2020; 368:290-296. [PMID: 32217751 DOI: 10.1126/science.aba8853] [Citation(s) in RCA: 576] [Impact Index Per Article: 144.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 03/16/2020] [Indexed: 12/18/2022]
Abstract
Manipulation of DNA by CRISPR-Cas enzymes requires the recognition of a protospacer-adjacent motif (PAM), limiting target site recognition to a subset of sequences. To remove this constraint, we engineered variants of Streptococcus pyogenes Cas9 (SpCas9) to eliminate the NGG PAM requirement. We developed a variant named SpG that is capable of targeting an expanded set of NGN PAMs, and we further optimized this enzyme to develop a near-PAMless SpCas9 variant named SpRY (NRN and to a lesser extent NYN PAMs). SpRY nuclease and base-editor variants can target almost all PAMs, exhibiting robust activities on a wide range of sites with NRN PAMs in human cells and lower but substantial activity on those with NYN PAMs. Using SpG and SpRY, we generated previously inaccessible disease-relevant genetic variants, supporting the utility of high-resolution targeting across genome editing applications.
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Affiliation(s)
- Russell T Walton
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Pathology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Kathleen A Christie
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Pathology, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Pathology, Harvard Medical School, Boston, MA 02115, USA
| | - Madelynn N Whittaker
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Pathology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Benjamin P Kleinstiver
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA 02114, USA. .,Department of Pathology, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Pathology, Harvard Medical School, Boston, MA 02115, USA
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8
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Steed L, Sohanpal R, Todd A, Madurasinghe VW, Rivas C, Edwards EA, Summerbell CD, Taylor SJC, Walton RT. Community pharmacy interventions for health promotion: effects on professional practice and health outcomes. Cochrane Database Syst Rev 2019; 12:CD011207. [PMID: 31808563 PMCID: PMC6896091 DOI: 10.1002/14651858.cd011207.pub2] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Community pharmacies are an easily accessible and cost-effective platform for delivering health care worldwide, and the range of services provided has undergone rapid expansion in recent years. Thus, in addition to dispensing medication, pharmacy workers within community pharmacies now give advice on a range of health-promoting behaviours that aim to improve health and to optimise the management of long-term conditions. However, it remains uncertain whether these health-promotion interventions can change the professional practice of pharmacy workers, improve health behaviours and outcomes for pharmacy users and have the potential to address health inequalities. OBJECTIVES To assess the effectiveness and safety of health-promotion interventions to change community pharmacy workers' professional practice and improve outcomes for users of community pharmacies. SEARCH METHODS We searched MEDLINE, Embase, CENTRAL, six other databases and two trials registers to 6 February 2018. We also conducted reference checking, citation searches and contacted study authors to identify any additional studies. SELECTION CRITERIA We included randomised trials of health-promotion interventions in community pharmacies targeted at, or delivered by, pharmacy workers that aimed to improve the health-related behaviour of people attending the pharmacy compared to no treatment, or usual treatment received in the community pharmacy. We excluded interventions where there was no interaction between pharmacy workers and pharmacy users, and those that focused on medication use only. DATA COLLECTION AND ANALYSIS We used standard procedures recommended by Cochrane and the Effective Practice and Organisation of Care review group for both data collection and analysis. We compared intervention to no intervention or to usual treatment using standardised mean differences (SMD) and 95% confidence intervals (95% CI) (higher scores represent better outcomes for pharmacy user health-related behaviour and quality of life, and lower scores represent better outcomes for clinical outcomes, costs and adverse events). Interpretation of effect sizes (SMD) was in line with Cochrane recommendations. MAIN RESULTS We included 57 randomised trials with 16,220 participants, described in 83 reports. Forty-nine studies were conducted in high-income countries, and eight in middle-income countries. We found no studies that had been conducted in low-income countries. Most interventions were educational, or incorporated skills training. Interventions were directed at pharmacy workers (n = 8), pharmacy users (n = 13), or both (n = 36). The clinical areas most frequently studied were diabetes, hypertension, asthma, and modification of cardiovascular risk. Duration of follow-up of interventions was often unclear. Only five studies gave details about the theoretical basis for the intervention, and studies did not provide sufficient data to comment on health inequalities. The most common sources of bias were lack of protection against contamination - mainly in individually randomised studies - and inadequate blinding of participants. The certainty of the evidence for all outcomes was moderate. We downgraded the certainty because of the heterogeneity across studies and evidence of potential publication bias. Professional practice outcomes We conducted a narrative analysis for pharmacy worker behaviour due to high heterogeneity in the results. Health-promotion interventions probably improve pharmacy workers' behaviour (2944 participants; 9 studies; moderate-certainty evidence) when compared to no intervention. These studies typically assessed behaviour using a simulated patient (mystery shopper) methodology. Pharmacy user outcomes Health-promotion interventions probably lead to a slight improvement in health-related behaviours of pharmacy users when compared to usual treatment (SMD 0.43, 95% CI 0.14 to 0.72; I2 = 89%; 10 trials; 2138 participants; moderate-certainty evidence). These interventions probably also lead to a slight improvement in intermediate clinical outcomes, such as levels of cholesterol or glycated haemoglobin, for pharmacy users (SMD -0.43, 95% CI -0.65 to -0.21; I2 = 90%; 20 trials; 3971 participants; moderate-certainty evidence). We identified no studies that evaluated the impact of health-promotion interventions on event-based clinical outcomes, such as stroke or myocardial infarction, or the psychological well-being of pharmacy users. Health-promotion interventions probably lead to a slight improvement in quality of life for pharmacy users (SMD 0.29, 95% CI 0.08 to 0.50; I2= 82%; 10 trials, 2687 participants; moderate-certainty evidence). Adverse events No studies reported adverse events for either pharmacy workers or pharmacy users. Costs We found that health-promotion interventions are likely to be cost-effective, based on moderate-certainty evidence from five of seven studies that reported an economic evaluation. AUTHORS' CONCLUSIONS Health-promotion interventions in the community pharmacy context probably improve pharmacy workers' behaviour and probably have a slight beneficial effect on health-related behaviour, intermediate clinical outcomes, and quality of life for pharmacy users. Such interventions are likely to be cost-effective and the effects are seen across a range of clinical conditions and health-related behaviours. Nevertheless the magnitude of the effects varies between conditions, and more effective interventions might be developed if greater consideration were given to the theoretical basis of the intervention and mechanisms for effecting behaviour change.
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Affiliation(s)
- Liz Steed
- Queen Mary University of LondonCentre for Primary Care and Public Health, Barts and The London School of Medicine and DentistryBlizard Institute, Yvonne Carter Building58 Turner StreetLondonUKE1 2AT
| | - Ratna Sohanpal
- Queen Mary University of LondonCentre for Primary Care and Public Health, Barts and The London School of Medicine and DentistryBlizard Institute, Yvonne Carter Building58 Turner StreetLondonUKE1 2AT
| | - Adam Todd
- Newcastle UniversitySchool of PharmacyQueen Victoria RoadNewcastle upon TyneUKNE1 7RU
| | - Vichithranie W Madurasinghe
- Queen Mary University of LondonCentre for Primary Care and Public Health, Barts and The London School of Medicine and DentistryBlizard Institute, Yvonne Carter Building58 Turner StreetLondonUKE1 2AT
| | - Carol Rivas
- University College LondonDepartment of Social Science, UCL Institute of Education18 Woburn SquareLondonUKWC1H 0NR
| | - Elizabeth A Edwards
- Queen Mary University of LondonCentre for Primary Care and Public Health, Barts and The London School of Medicine and DentistryBlizard Institute, Yvonne Carter Building58 Turner StreetLondonUKE1 2AT
| | - Carolyn D Summerbell
- Durham UniversityDepartment of Sport and Exercise Sciences42 Old ElvetDurhamUKDH13HN
| | - Stephanie JC Taylor
- Queen Mary University of LondonCentre for Primary Care and Public Health, Barts and The London School of Medicine and DentistryBlizard Institute, Yvonne Carter Building58 Turner StreetLondonUKE1 2AT
- Queen Mary University of LondonAsthma UK Centre for Applied ResearchLondonUK
| | - RT Walton
- Queen Mary University of LondonCentre for Primary Care and Public Health, Barts and The London School of Medicine and DentistryBlizard Institute, Yvonne Carter Building58 Turner StreetLondonUKE1 2AT
- Queen Mary University of LondonAsthma UK Centre for Applied ResearchLondonUK
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9
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Kleinstiver BP, Sousa AA, Walton RT, Tak YE, Hsu JY, Clement K, Welch MM, Horng JE, Malagon-Lopez J, Scarfò I, Maus MV, Pinello L, Aryee MJ, Joung JK. Engineered CRISPR-Cas12a variants with increased activities and improved targeting ranges for gene, epigenetic and base editing. Nat Biotechnol 2019; 37:276-282. [PMID: 30742127 PMCID: PMC6401248 DOI: 10.1038/s41587-018-0011-0] [Citation(s) in RCA: 347] [Impact Index Per Article: 69.4] [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: 07/05/2018] [Accepted: 12/21/2018] [Indexed: 02/08/2023]
Abstract
Broad use of CRISPR-Cas12a (formerly Cpf1) nucleases1 has been hindered by the requirement for
an extended TTTV protospacer adjacent motif (PAM)2. To address this limitation, we
engineered an enhanced Acidaminococcus sp. Cas12a variant
(enAsCas12a) that has a substantially expanded targeting range, enabling
targeting of many previously inaccessible PAMs. On average, enAsCas12a exhibits
two-fold higher genome editing activity on sites with canonical TTTV PAMs
compared to wild-type AsCas12a, and we successfully grafted a subset of
mutations from enAsCas12a onto other previously described AsCas12a
variants3 to enhance
their activities. enAsCas12a improves the efficiency of multiplex gene editing,
endogenous gene activation, and C-to-T base editing, and we engineered a
high-fidelity version of enAsCas12a (enAsCas12a-HF1) to reduce off-target
effects. Both enAsCas12a and enAsCas12a-HF1 function in HEK293T and primary
human T cells when delivered as ribonucleoprotein (RNP) complexes. Collectively,
enAsCas12a provides an optimized version of Cas12a that should enable wider
application of Cas12a enzymes for gene and epigenetic editing. [AU: Revised
abstract OK?]
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Affiliation(s)
- Benjamin P Kleinstiver
- Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, MA, USA. .,Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA, USA. .,Center for Computational and Integrative Biology, Massachusetts General Hospital, Charlestown, MA, USA. .,Department of Pathology, Harvard Medical School, Boston, MA, USA. .,Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.
| | - Alexander A Sousa
- Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, MA, USA.,Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA, USA.,Center for Computational and Integrative Biology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Russell T Walton
- Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, MA, USA.,Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA, USA.,Center for Computational and Integrative Biology, Massachusetts General Hospital, Charlestown, MA, USA.,Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Y Esther Tak
- Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, MA, USA.,Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA, USA.,Center for Computational and Integrative Biology, Massachusetts General Hospital, Charlestown, MA, USA.,Department of Pathology, Harvard Medical School, Boston, MA, USA
| | - Jonathan Y Hsu
- Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, MA, USA.,Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA, USA.,Center for Computational and Integrative Biology, Massachusetts General Hospital, Charlestown, MA, USA.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Kendell Clement
- Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, MA, USA.,Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA, USA.,Department of Pathology, Harvard Medical School, Boston, MA, USA.,Cell Circuits and Epigenomics Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Moira M Welch
- Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, MA, USA.,Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA, USA.,Center for Computational and Integrative Biology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Joy E Horng
- Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, MA, USA.,Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA, USA.,Center for Computational and Integrative Biology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Jose Malagon-Lopez
- Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, MA, USA.,Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA, USA.,Center for Computational and Integrative Biology, Massachusetts General Hospital, Charlestown, MA, USA.,Department of Pathology, Harvard Medical School, Boston, MA, USA.,Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA.,Advance Artificial Intelligence Research Laboratory, WuXi NextCODE, Cambridge, MA, USA
| | - Irene Scarfò
- Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA, USA.,Cellular Immunotherapy Program, Cancer Center, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Marcela V Maus
- Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA, USA.,Cellular Immunotherapy Program, Cancer Center, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Luca Pinello
- Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, MA, USA.,Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA, USA.,Department of Pathology, Harvard Medical School, Boston, MA, USA.,Cell Circuits and Epigenomics Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Martin J Aryee
- Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, MA, USA.,Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA, USA.,Department of Pathology, Harvard Medical School, Boston, MA, USA.,Cell Circuits and Epigenomics Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - J Keith Joung
- Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, MA, USA. .,Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA, USA. .,Center for Computational and Integrative Biology, Massachusetts General Hospital, Charlestown, MA, USA. .,Department of Pathology, Harvard Medical School, Boston, MA, USA.
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10
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Marino ND, Zhang JY, Borges AL, Sousa AA, Leon LM, Rauch BJ, Walton RT, Berry JD, Joung JK, Kleinstiver BP, Bondy-Denomy J. Discovery of widespread type I and type V CRISPR-Cas inhibitors. Science 2018; 362:240-242. [PMID: 30190308 DOI: 10.1126/science.aau5174] [Citation(s) in RCA: 160] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 08/25/2018] [Indexed: 12/31/2022]
Abstract
Bacterial CRISPR-Cas systems protect their host from bacteriophages and other mobile genetic elements. Mobile elements, in turn, encode various anti-CRISPR (Acr) proteins to inhibit the immune function of CRISPR-Cas. To date, Acr proteins have been discovered for type I (subtypes I-D, I-E, and I-F) and type II (II-A and II-C) but not other CRISPR systems. Here, we report the discovery of 12 acr genes, including inhibitors of type V-A and I-C CRISPR systems. AcrVA1 inhibits a broad spectrum of Cas12a (Cpf1) orthologs-including MbCas12a, Mb3Cas12a, AsCas12a, and LbCas12a-when assayed in human cells. The acr genes reported here provide useful biotechnological tools and mark the discovery of acr loci in many bacteria and phages.
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Affiliation(s)
- Nicole D Marino
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Jenny Y Zhang
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Adair L Borges
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Alexander A Sousa
- Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, MA 02129, USA.,Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA 02129, USA.,Center for Computational and Integrative Biology, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | - Lina M Leon
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Benjamin J Rauch
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Russell T Walton
- Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, MA 02129, USA.,Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA 02129, USA.,Center for Computational and Integrative Biology, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | - Joel D Berry
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - J Keith Joung
- Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, MA 02129, USA.,Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA 02129, USA.,Center for Computational and Integrative Biology, Massachusetts General Hospital, Charlestown, MA 02129, USA.,Department of Pathology, Harvard Medical School, Boston, MA 02115, USA
| | - Benjamin P Kleinstiver
- Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, MA 02129, USA.,Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA 02129, USA.,Center for Computational and Integrative Biology, Massachusetts General Hospital, Charlestown, MA 02129, USA.,Department of Pathology, Harvard Medical School, Boston, MA 02115, USA
| | - Joseph Bondy-Denomy
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA. .,Quantitative Biosciences Institute, University of California, San Francisco, San Francisco, CA 94143, USA
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11
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Edwards EA, Lumsden J, Rivas C, Steed L, Edwards LA, Thiyagarajan A, Sohanpal R, Caton H, Griffiths CJ, Munafò MR, Taylor S, Walton RT. Gamification for health promotion: systematic review of behaviour change techniques in smartphone apps. BMJ Open 2016; 6:e012447. [PMID: 27707829 PMCID: PMC5073629 DOI: 10.1136/bmjopen-2016-012447] [Citation(s) in RCA: 187] [Impact Index Per Article: 23.4] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
OBJECTIVE Smartphone games that aim to alter health behaviours are common, but there is uncertainty about how to achieve this. We systematically reviewed health apps containing gaming elements analysing their embedded behaviour change techniques. METHODS Two trained researchers independently coded apps for behaviour change techniques using a standard taxonomy. We explored associations with user ratings and price. DATA SOURCES We screened the National Health Service (NHS) Health Apps Library and all top-rated medical, health and wellness and health and fitness apps (defined by Apple and Google Play stores based on revenue and downloads). We included free and paid English language apps using 'gamification' (rewards, prizes, avatars, badges, leaderboards, competitions, levelling-up or health-related challenges). We excluded apps targeting health professionals. RESULTS 64 of 1680 (4%) health apps included gamification and met inclusion criteria; only 3 of these were in the NHS Library. Behaviour change categories used were: feedback and monitoring (n=60, 94% of apps), reward and threat (n=52, 81%), and goals and planning (n=52, 81%). Individual techniques were: self-monitoring of behaviour (n=55, 86%), non-specific reward (n=49, 82%), social support unspecified (n=48, 75%), non-specific incentive (n=49, 82%) and focus on past success (n=47, 73%). Median number of techniques per app was 14 (range: 5-22). Common combinations were: goal setting, self-monitoring, non-specific reward and non-specific incentive (n=35, 55%); goal setting, self-monitoring and focus on past success (n=33, 52%). There was no correlation between number of techniques and user ratings (p=0.07; rs=0.23) or price (p=0.45; rs=0.10). CONCLUSIONS Few health apps currently employ gamification and there is a wide variation in the use of behaviour change techniques, which may limit potential to improve health outcomes. We found no correlation between user rating (a possible proxy for health benefits) and game content or price. Further research is required to evaluate effective behaviour change techniques and to assess clinical outcomes. TRIAL REGISTRATION NUMBER CRD42015029841.
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Affiliation(s)
- E A Edwards
- Centre for Primary Care and Public Health, Bart's and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - J Lumsden
- School of Experimental Psychology, University of Bristol, Bristol, UK MRC Integrative Epidemiology Unit at the University of Bristol, Bristol, UK
| | - C Rivas
- Centre for Primary Care and Public Health, Bart's and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK Faculty of Health Sciences, University of Southampton, Southampton, UK
| | - L Steed
- Centre for Primary Care and Public Health, Bart's and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - L A Edwards
- Institute of Liver Studies, King's College Hospital, London, UK
| | - A Thiyagarajan
- Centre for Primary Care and Public Health, Bart's and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - R Sohanpal
- Centre for Primary Care and Public Health, Bart's and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - H Caton
- Department of Computing and Information Systems, Kingston University, London, UK
| | - C J Griffiths
- Centre for Primary Care and Public Health, Bart's and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - M R Munafò
- School of Experimental Psychology, University of Bristol, Bristol, UK MRC Integrative Epidemiology Unit at the University of Bristol, Bristol, UK
| | - S Taylor
- Centre for Primary Care and Public Health, Bart's and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - R T Walton
- Centre for Primary Care and Public Health, Bart's and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
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12
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Steed L, Kassavou A, Madurasinghe VW, Edwards EA, Todd A, Summerbell CD, Nkansah N, Bero L, Durieux P, Taylor SJC, Rivas C, Walton RT. Community pharmacy interventions for health promotion: effects on professional practice and health outcomes. Cochrane Database of Systematic Reviews 2014. [DOI: 10.1002/14651858.cd011207] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Liz Steed
- Barts and The London School of Medicine and Dentistry, Queen Mary University of London; Centre for Primary Care and Public Health; Blizard Institute, Yvonne Carter Building 58 Turner Street London UK E1 2AT
| | - Aikaterini Kassavou
- University of Cambridge; Behavioural Science Group; Forvie Site, Robinson Way Cambridge UK CB2 0SR
| | - Vichithranie W Madurasinghe
- Queen Mary University of London; Centre for Primary Care and Public Health, Barts & The London School of Medicine and Dentistry; Yvonne Carter Building, 58 Turner Street London UK
| | - Elizabeth Ann Edwards
- Queen Mary University of London; Centre for Primary Care and Public Health, Barts & The London School of Medicine and Dentistry; Yvonne Carter Building, 58 Turner Street London UK
| | - Adam Todd
- Durham University; School of Medicine, Pharmacy and Health, Wolfson Research Institute; University Boulevard Thornaby Stockton-on-Tees UK TS17 6BH
| | - Carolyn D Summerbell
- Queen's Campus, Durham University; School of Medicine, Pharmacy and Health, Wolfson Research Institute; University Boulevard Thornaby Stockton-on-Tees UK TS17 6BH
| | - Nancy Nkansah
- University of California; Clinical Pharmacy; 155 North Fresno Street, Suite 224 San Francisco California USA 93701
| | - Lisa Bero
- Charles Perkins Centre, University of Sydney; Medicines Use and Health Outcomes; 6th Floor (6W76) University of Sydney Camperdown New South Wales 2006 Australia
| | - Pierre Durieux
- Georges Pompidou European Hospital, Paris Descartes University, INSERM U872 eq 22; Department of Public Health and Medical Informatics; 20 rue Leblanc Paris France 75015
| | - Stephanie JC Taylor
- Centre for Primary Care and Public Health, Barts & The London School of Medicine and Dentistry, Queen Mary University of London; Yvonne Carter Building 58 Turner Street London UK E1 2AB
| | - Carol Rivas
- Queen Mary University of London; Centre for Primary Care and Public Health, Barts and The London School of Medicine and Dentistry; 58 Turner Street London UK E1 2AB
| | - RT Walton
- Queen Mary University of London; Centre for Primary Care and Public Health, Barts & The London School of Medicine and Dentistry; Yvonne Carter Building, 58 Turner Street London UK
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13
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Gillaizeau F, Chan E, Trinquart L, Colombet I, Walton RT, Rège-Walther M, Burnand B, Durieux P. Computerized advice on drug dosage to improve prescribing practice. Cochrane Database Syst Rev 2013:CD002894. [PMID: 24218045 DOI: 10.1002/14651858.cd002894.pub3] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
BACKGROUND Maintaining therapeutic concentrations of drugs with a narrow therapeutic window is a complex task. Several computer systems have been designed to help doctors determine optimum drug dosage. Significant improvements in health care could be achieved if computer advice improved health outcomes and could be implemented in routine practice in a cost-effective fashion. This is an updated version of an earlier Cochrane systematic review, first published in 2001 and updated in 2008. OBJECTIVES To assess whether computerized advice on drug dosage has beneficial effects on patient outcomes compared with routine care (empiric dosing without computer assistance). SEARCH METHODS The following databases were searched from 1996 to January 2012: EPOC Group Specialized Register, Reference Manager; Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Ovid; EMBASE, Ovid; and CINAHL, EbscoHost. A "top up" search was conducted for the period January 2012 to January 2013; these results were screened by the authors and potentially relevant studies are listed in Studies Awaiting Classification. The review authors also searched reference lists of relevant studies and related reviews. SELECTION CRITERIA We included randomized controlled trials, non-randomized controlled trials, controlled before-and-after studies and interrupted time series analyses of computerized advice on drug dosage. The participants were healthcare professionals responsible for patient care. The outcomes were any objectively measured change in the health of patients resulting from computerized advice (such as therapeutic drug control, clinical improvement, adverse reactions). DATA COLLECTION AND ANALYSIS Two review authors independently extracted data and assessed study quality. We grouped the results from the included studies by drug used and the effect aimed at for aminoglycoside antibiotics, amitriptyline, anaesthetics, insulin, anticoagulants, ovarian stimulation, anti-rejection drugs and theophylline. We combined the effect sizes to give an overall effect for each subgroup of studies, using a random-effects model. We further grouped studies by type of outcome when appropriate (i.e. no evidence of heterogeneity). MAIN RESULTS Forty-six comparisons (from 42 trials) were included (as compared with 26 comparisons in the last update) including a wide range of drugs in inpatient and outpatient settings. All were randomized controlled trials except two studies. Interventions usually targeted doctors, although some studies attempted to influence prescriptions by pharmacists and nurses. Drugs evaluated were anticoagulants, insulin, aminoglycoside antibiotics, theophylline, anti-rejection drugs, anaesthetic agents, antidepressants and gonadotropins. Although all studies used reliable outcome measures, their quality was generally low.This update found similar results to the previous update and managed to identify specific therapeutic areas where the computerized advice on drug dosage was beneficial compared with routine care:1. it increased target peak serum concentrations (standardized mean difference (SMD) 0.79, 95% CI 0.46 to 1.13) and the proportion of people with plasma drug concentrations within the therapeutic range after two days (pooled risk ratio (RR) 4.44, 95% CI 1.94 to 10.13) for aminoglycoside antibiotics;2. it led to a physiological parameter more often within the desired range for oral anticoagulants (SMD for percentage of time spent in target international normalized ratio +0.19, 95% CI 0.06 to 0.33) and insulin (SMD for percentage of time in target glucose range: +1.27, 95% CI 0.56 to 1.98);3. it decreased the time to achieve stabilization for oral anticoagulants (SMD -0.56, 95% CI -1.07 to -0.04);4. it decreased the thromboembolism events (rate ratio 0.68, 95% CI 0.49 to 0.94) and tended to decrease bleeding events for anticoagulants although the difference was not significant (rate ratio 0.81, 95% CI 0.60 to 1.08). It tended to decrease unwanted effects for aminoglycoside antibiotics (nephrotoxicity: RR 0.67, 95% CI 0.42 to 1.06) and anti-rejection drugs (cytomegalovirus infections: RR 0.90, 95% CI 0.58 to 1.40);5. it tended to reduce the length of time spent in the hospital although the difference was not significant (SMD -0.15, 95% CI -0.33 to 0.02) and to achieve comparable or better cost-effectiveness ratios than usual care;6. there was no evidence of differences in mortality or other clinical adverse events for insulin (hypoglycaemia), anaesthetic agents, anti-rejection drugs and antidepressants.For all outcomes, statistical heterogeneity quantified by I(2) statistics was moderate to high. AUTHORS' CONCLUSIONS This review update suggests that computerized advice for drug dosage has some benefits: it increases the serum concentrations for aminoglycoside antibiotics and improves the proportion of people for which the plasma drug is within the therapeutic range for aminoglycoside antibiotics.It leads to a physiological parameter more often within the desired range for oral anticoagulants and insulin. It decreases the time to achieve stabilization for oral anticoagulants. It tends to decrease unwanted effects for aminoglycoside antibiotics and anti-rejection drugs, and it significantly decreases thromboembolism events for anticoagulants. It tends to reduce the length of hospital stay compared with routine care while comparable or better cost-effectiveness ratios were achieved.However, there was no evidence that decision support had an effect on mortality or other clinical adverse events for insulin (hypoglycaemia), anaesthetic agents, anti-rejection drugs and antidepressants. In addition, there was no evidence to suggest that some decision support technical features (such as its integration into a computer physician order entry system) or aspects of organization of care (such as the setting) could optimize the effect of computerized advice.Taking into account the high risk of bias of, and high heterogeneity between, studies, these results must be interpreted with caution.
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Affiliation(s)
- Florence Gillaizeau
- French Cochrane Center, Hôpital Hôtel-Dieu, 1 place du Parvis Notre-Dame, Paris, France, 75004
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David SP, Munafò MR, Murphy MFG, Proctor M, Walton RT, Johnstone EC. Genetic variation in the dopamine D4 receptor (DRD4) gene and smoking cessation: follow-up of a randomised clinical trial of transdermal nicotine patch. Pharmacogenomics J 2007; 8:122-8. [PMID: 17387332 PMCID: PMC2288552 DOI: 10.1038/sj.tpj.6500447] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Smokers of European ancestry (n=720) who participated in a double-blind, randomised, placebo-controlled trial of transdermal nicotine replacement therapy, were genotyped for two functional polymorphisms (variable number of tandem repeats (VNTR) and a C to T transition at position -521 (C-521T)) in the dopamine D4 receptor gene (DRD4) gene. Logistic regression models of abstinence at 12- and 26-week follow-ups were carried out separately for each polymorphism. For the DRD4 VNTR models, the main effect of treatment was significant at both 12-week (P=0.001) and 26-week (P=0.006) follow-ups, indicating an increased likelihood of successful cessation on active nicotine replacement therapy transdermal patch relative to placebo. The main effect of DRD4 VNTR genotype was associated with abstinence at 12-week follow-up (P=0.034), with possession of one or more copies of the long allele associated with reduced likelihood of cessation (17 vs 23%), but this effect was not observed at 26-week follow-up. For the DRD4 C-521T models, no main effect or interaction terms involving genotype were retained in the models at either 12- or 26-week follow-up. These data are consistent with observations from studies of the DRD2 gene that genetic variants related to relatively decreased dopaminergic tone in the mesocorticolimbic system are associated with increased risk for relapse to smoking following a cessation attempt.
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Affiliation(s)
- S P David
- Brown Medical School/Memorial Hospital of Rhode Island, Pawtucket, RI, USA.
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Munafò MR, Elliot KM, Murphy MFG, Walton RT, Johnstone EC. Association of the mu-opioid receptor gene with smoking cessation. Pharmacogenomics J 2007; 7:353-61. [PMID: 17224915 DOI: 10.1038/sj.tpj.6500432] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We investigated the association of the OPRM1 genotype with long-term smoking cessation and change in body mass index (BMI) following a smoking cessation attempt among smokers who attempted to quit using the nicotine replacement therapy (NRT) patch or placebo in a randomized controlled trial, and were followed-up over an 8-year period following their initial cessation attempt. We also investigated possible sex differences in these relationships, given evidence for sex differences in smoking cessation and central opioid mechanisms, as well as some evidence for sex differences in response to NRT. Our results indicate that OPRM1 genotype may moderate the effect of transdermal nicotine patch compared to placebo during active treatment, with a benefit of active NRT treatment evident in the OPRM1 AA genotype group only and those carrying one or more copies of the G allele demonstrating no benefit of active NRT versus placebo patch. Our results also indicate a sex difference in change in BMI at 8-year follow-up following a smoking cessation attempt, with ex-smokers demonstrating an increase in BMI, and this increase being greater in female subjects than in male subjects. We did not observe any association of OPRM1 genotype with change in BMI, although there was a trend for genotype to influence the observed sex difference in change in BMI over time. Future studies should attempt to replicate these findings, and investigate the relationship between both short- and long-term weight gain and smoking cessation and investigate possible mechanisms that may underlie these processes. Future studies should also investigate the role of OPRM1 genotype and smoking cessation on other appetitive and reward behaviours such as alcohol consumption.
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Affiliation(s)
- M R Munafò
- Department of Experimental Psychology, University of Bristol, Bristol, UK.
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Munafò MR, Johnstone EC, Welsh KI, Walton RT. Association between the DRD2 gene Taq1A (C32806T) polymorphism and alcohol consumption in social drinkers. Pharmacogenomics J 2005; 5:96-101. [PMID: 15668731 DOI: 10.1038/sj.tpj.6500294] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An association between the DRD2 Taq1A (C32806T) polymorphism and social alcohol consumption in the opposite direction to that reported for alcoholism has recently been reported in a male Finnish sample. We attempted to replicate these findings in two independent samples, and extend on previous work by including female participants. The DRD2 A1 allele was significantly associated with reduced alcohol consumption in sample one (P=0.004) and sample two (P=0.015). In sample two there was a significant genotype x sex interaction (P=0.016), with the association of the A1 allele and reduced alcohol consumption significant in men only. This interaction was marginally significant (P=0.042) in a meta-analysis of combined data from both samples, and the main effect of genotype highly significant (P<0.001). Age at time of data collection and cigarette consumption were entered as covariates in all analyses. These results replicate recent previous findings and suggest a possibility that this association may exist in men only, or be stronger in men.
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Affiliation(s)
- M R Munafò
- Cancer Research UK General Practice Research Group, Department of Clinical Pharmacology, University of Oxford, Oxford, UK.
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Abstract
BACKGROUND Maintaining therapeutic concentrations of toxic drugs is a complex task. Several computer systems have been designed to help doctors determine optimum drug dosage. Significant improvements in health could be achieved if computer advice was shown to be beneficial. OBJECTIVES To assess whether computer support for drug dosage benefits patients and hence whether it should be more widely available. SEARCH STRATEGY We searched the Cochrane Effective Practice and Organisation of Care Group specialised register (June 1996), MEDLINE (1966 to June 1996), EMBASE (1980 to June 1996), hand searched the journal Therapeutic Drug Monitoring (1979 to June 1996), reference lists of articles and contacted experts in the field. SELECTION CRITERIA Randomised trials, interrupted time series and controlled before and after studies of computerised advice on drug dosage. The participants were health professionals responsible for patient care. The outcomes were: any objectively measured change in the behaviour of the health care provider (such as changes in the dose of drug used); any change in the health of patients, resulting from computer support (such as adverse reactions to drugs). DATA COLLECTION AND ANALYSIS Two reviewers independently extracted data and assessed study quality. MAIN RESULTS Fifteen trials involving 1229 patients were included. The drugs studied were theophylline, warfarin, heparin, aminoglycosides, nitroprusside, lignocaine, oxytocin, fentanyl and midazolam. Interventions usually targeted doctors although some studies attempted to influence prescribing by pharmacists and nurses. All included studies took place on acute medical conditions in hospital settings. Although all studies used reliable outcome measures, sample size was often small and only two studies reported a sample size calculation. Computer support for drug dosage gave significant benefits reducing: 1. The time to achieve therapeutic control (standardised mean difference -0.44, 95% CI -0.70 to -0.17); 2. Toxic drug levels (risk difference -0.12, 95% CI -0.24 to -0.01); 3. Adverse reactions (risk difference -0.06, 95% CI -0.12 to 0.00); 4. Length of hospital stay (standardised mean difference -0.32, 95% CI -0.60 to -0.04). There was a tendency for computer support to result in higher doses of drugs, although this did not reach statistical significance. REVIEWER'S CONCLUSIONS This systematic review provides evidence to support the use of computer assistance in determining drug dosage. Further clinical trials are necessary to determine whether the benefits seen in specialist applications can be realised in general use.
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Affiliation(s)
- R T Walton
- University of Oxford Department of Public Health and Primary Care, Imperial Cancer Research Fund General Practice Research Group, Institute of Health Sciences, Old Road, Headington, Oxford, UK, OX3 7LF.
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McKinney EF, Walton RT, Yudkin P, Fuller A, Haldar NA, Mant D, Murphy M, Welsh KI, Marshall SE. Association between polymorphisms in dopamine metabolic enzymes and tobacco consumption in smokers. Pharmacogenetics 2000; 10:483-91. [PMID: 10975602 DOI: 10.1097/00008571-200008000-00001] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Central dopaminergic reward pathways give rise to dependence and are activated by nicotine. Allelic variants in genes involved in dopamine metabolism may therefore influence the amount of tobacco consumed by smokers. We developed assays for polymorphisms in dopamine beta-hydroxylase (DBH), monoamine oxidase (MAO) and catechol O-methyl transferase (COMT) using the polymerase chain reaction with sequence specific primers (PCR-SSP). We then typed 225 cigarette smokers to assess whether genotype was related to the number of cigarettes smoked a day. Smokers with DBH 1368 GG genotype smoked fewer cigarettes than those with GA/AA [mean difference -2.9 cigarettes, 95% confidence interval (CI) -5.5, -0.4; P = 0.022]. The effect reached statistical significance in women (-3.8, 95% CI -6.4, -1.0, P = 0.007) but not in men (-1.5, 95% CI -6.0, 3.0, P = 0.498). Overall, the effect was greater when analysis was confined to Caucasians (-3.8, 95% CI -6.6, -1.1, P = 0.007). Smokers with MAO-A 1460 TT/TO smoked more cigarettes than those with CC/CT/CO (2.9, 95% CI 0.6, 5.1, P = 0.013). Within each sex group, the trend was similar but not statistically significant (difference for men 2.9, 95% CI -1.0, 6.7; for women 2.0, 95% CI -0.7, 4.8). The effect of the allele was greater in smokers with a high body mass index (> 26) (difference 5.1, 95% CI 1.4, 8.8, P = 0.008). More heavy smokers (> 20 a day) had the DBH 1368A allele when compared to light smokers (< 10 a day). (Relative risk 2.3, 95% CI 1.1, 5.0, P = 0.024.) The trend for increasing prevalence of the DBH A allele in heavy smokers was greater when analysis was restricted to Caucasians (relative risk 3.2, 95% CI 1.3, 8.2, P = 0.004). Conversely, heavy smokers were less likely to have the MAO-A 1460C allele (relative risk 0.3, 95% CI 0.1, 0.7, P = 0.012). Variations in DBH and MAO predict whether a person is a heavy smoker and how many cigarettes they consume. Our results support the view that these enzymes help to determine a smoker's requirement for nicotine and may explain why some people are predisposed to tobacco addiction and why some find it very difficult to stop smoking. This finding has important implications for smoking prevention and offers potential for developing patient-specific therapy for smoking cessation.
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Affiliation(s)
- E F McKinney
- Transplant Immunology, Oxford Transplant Centre, UK
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Abstract
OBJECTIVE To evaluate the potential effect of computer support on general practitioners' prescribing, and to compare the effectiveness of three different support levels. DESIGN Crossover experiment with balanced block design. SUBJECTS Random sample of 50 general practitioners (42 agreed to participate) from 165 in a geographically defined area of Oxfordshire. INTERVENTIONS Doctors prescribed for 36 simulated cases constructed from real consultations. Levels of computer support were control (alphabetical list of drugs), limited support (list of preferred drugs), and full support (the same list with explanations available for suggestions). MAIN OUTCOME MEASURES Percentage of cases where doctors ignored a cheaper, equally effective drug; prescribing score (a measure of how closely prescriptions matched expert recommendations); interview to elicit doctors' views of support system. RESULTS Computer support significantly improved the quality of prescribing. Doctors ignored a cheaper, equally effective drug in a median 50% (range 25%-75%) of control cases, compared with 36% (8%-67%) with limited support and 35% (0-67%) with full support (P < 0.001). The median prescribing score rose from 6.0 units (4.2-7.0) with control support to 6.8 (5.8 to 7.7) and 6.7 (5.6 to 7.8) with limited and full support (P < 0.001). Of 41 doctors, 36 (88%) found the system easy to use and 24 (59%) said they would be likely to use it in practice. CONCLUSIONS Computer support improved compliance with prescribing guidelines, reducing the occasions when doctors ignored a cheaper, equally effective drug. The system was easy to operate, and most participating doctors would be likely to use it in practice.
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Affiliation(s)
- R T Walton
- Department of Public Health and Primary Care, Radcliffe Infirmary, Oxford.
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