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Sofen H, Bissonnette R, Yosipovitch G, Silverberg JI, Tyring S, Loo WJ, Zook M, Lee M, Zou L, Jiang GL, Paolini JF. Efficacy and safety of vixarelimab, a human monoclonal oncostatin M receptor β antibody, in moderate-to-severe prurigo nodularis: a randomised, double-blind, placebo-controlled, phase 2a study. EClinicalMedicine 2023; 57:101826. [PMID: 36816342 PMCID: PMC9932343 DOI: 10.1016/j.eclinm.2023.101826] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 12/16/2022] [Accepted: 01/04/2023] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Prurigo nodularis is a chronic skin disease characterised by intensely pruritic, hyperkeratotic nodules. Vixarelimab, a human monoclonal antibody, binds to the beta subunit of the oncostatin M receptor, inhibiting signalling of both interleukin 31 and oncostatin M, two cytokine pathways that contribute to pruritus and nodule formation in prurigo nodularis. METHODS This double-blind, placebo-controlled, phase 2a trial was done at both private and academic dermatology outpatient research clinics across the United States and Canada (n = 40). Patient eligibility criteria included age 18-75 years, physician-documented diagnosis of prurigo nodularis minimum 6 months duration of prurigo nodularis, presence of at least 10 pruritic nodules approximately 0.5-2 cm in size on at least two different anatomical locations (excluding face and scalp) and involving the extremities, and presence of normal-appearing skin between nodules; atopic dermatitis as a comorbidity was exclusionary. Patients were required to have moderate-to-severe pruritus, defined as Worst Itch-Numeric Rating Scale (WI-NRS) score ≥7 at screening and LS-mean weekly WI-NRS score ≥5 for each of the 2 consecutive weeks immediately before randomisation. Participants were randomly assigned (1:1) to receive weekly subcutaneous vixarelimab 360 mg (720 mg loading dose) or placebo using stratification factors (sex and presence of atopy) and block size 4 through the IWRS system. Stratification by atopy status was based on the reported high prevalence of atopy in this population and the potential impact of atopy in the immunopathologic process in prurigo nodularis. Patients, investigators, study sponsor, and site staff were masked to study treatment. The primary efficacy endpoint was least squares (LS)-mean percent change from baseline (PCFB) at Week 8 in weekly average Worst Itch-Numeric Rating Scale (WI-NRS) score. The primary efficacy endpoint was analysed with ANCOVA including treatment as fixed effect, with baseline WI-NRS, and randomisation stratification factor as covariates. All randomised patients who had at least 1 dose of study drug or placebo were included in the Safety Analysis Set. This trial is registered at ClinicalTrials.gov, NCT03816891. FINDINGS Of 50 patients randomised between March 11, 2019 and January 31, 2020, 23 vixarelimab recipients and 26 placebo recipients comprised the modified intent-to-treat analysis population (baseline LS-mean [SD] WI-NRS score, 8.3 [1.05]). Outcomes at Week 8 for vixarelimab versus placebo included LS-mean PCFB in WI-NRS score, -50.6% versus -29.4% (LS-mean difference [95% CI], -21.2% [-40.82, -1.60]; p = 0.03); ≥4-point reduction in WI-NRS score, 52.2% (12/23) versus 30.8% (8/26) (p = 0.11); PN-IGA score of 0 or 1, 30.4% (7/23) versus 7.7% (2/26) (p = 0.03); LS-mean PCFB in pruritus VAS score, -54.4% versus -32.6% (p = 0.03); and LS-mean PCFB sleep loss reduction (improvement), -56.3% versus -30.0% (p = 0.02). No deaths, serious TEAEs, or TEAEs leading to dose interruption were reported. The percentage of vixarelimab recipients reporting any TEAE was 91.3% (21/23) versus 76.9% (20/26) of placebo recipients; drug-related TEAEs generally were similar between the two groups (vixarelimab, 43.5% [10/23]; placebo, 38.5% [10/26]). INTERPRETATION Vixarelimab demonstrated rapid reduction of pruritus and achievement of clear/almost clear skin in one-third of the patients by Week 8. Relief of itch and clearing of skin nodules represent two important potential therapeutic advances in the management of patients suffering from the debilitating disease Prurigo Nodularis. FUNDING Kiniksa Pharmaceuticals, Ltd.
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Affiliation(s)
- Howard Sofen
- UCLA School of Medicine, Los Angeles, CA, USA
- Corresponding author. Department of Medicine/Dermatology, David Geffen UCLA School of Medicine, Los Angeles, CA, 90045, USA.
| | | | - Gil Yosipovitch
- University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jonathan I. Silverberg
- George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | - Stephen Tyring
- Department of Dermatology and Centre for Clinical Studies, University of Texas Health Science Centre, Houston, TX, USA
| | - Wei Jing Loo
- Derm Effects & Probity Medical Research, London, Ontario, Canada
| | | | - Mark Lee
- Progressive Clinical Research, San Antonio, TX, USA
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Abstract
The mobility restrictions related to COVID-19 pandemic have resulted in the biggest disruption to individual mobilities in modern times. The crisis is clearly spatial in nature, and examining the geographical aspect is important in understanding the broad implications of the pandemic. The avalanche of mobile Big Data makes it possible to study the spatial effects of the crisis with spatiotemporal detail at the national and global scales. However, the current crisis also highlights serious limitations in the readiness to take the advantage of mobile Big Data for social good, both within and beyond the interests of health sector. We propose two strategical pathways for the future use of mobile Big Data for societal impact assessment, addressing access to both raw mobile Big Data as well as aggregated data products. Both pathways require careful considerations of privacy issues, harmonized and transparent methodologies, and attention to the representativeness, reliability and continuity of data. The goal is to be better prepared to use mobile Big Data in future crises.
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Affiliation(s)
- Age Poom
- Digital Geography Lab, Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland
- Helsinki Institute of Sustainability Science, Institute of Urban and Regional Studies, University of Helsinki, Helsinki, Finland
- Mobility Lab, Department of Geography, University of Tartu, Tartu, Estonia
- Age Poom, University of Helsinki, Gustaf Hällströmin katu 2, Helsinki 00014, Finland.
| | - Olle Järv
- Digital Geography Lab, Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland
- Helsinki Institute of Sustainability Science, Institute of Urban and Regional Studies, University of Helsinki, Helsinki, Finland
| | - Matthew Zook
- Department of Geography, University of Kentucky, Lexington, KY, USA
| | - Tuuli Toivonen
- Digital Geography Lab, Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland
- Helsinki Institute of Sustainability Science, Institute of Urban and Regional Studies, University of Helsinki, Helsinki, Finland
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Bissonnette R, Maari C, Forman S, Bhatia N, Lee M, Fowler J, Tyring S, Pariser D, Sofen H, Dhawan S, Zook M, Zammit D, Usansky H, Denis L, Rao N, Song T, Pavel A, Guttman‐Yassky E. ASN002 证明有疗效并可改善AD 炎症. Br J Dermatol 2019. [DOI: 10.1111/bjd.18409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Bissonnette R, Maari C, Forman S, Bhatia N, Lee M, Fowler J, Tyring S, Pariser D, Sofen H, Dhawan S, Zook M, Zammit D, Usansky H, Denis L, Rao N, Song T, Pavel A, Guttman‐Yassky E. The oral Janus kinase/spleen tyrosine kinase inhibitor ASN002 demonstrates efficacy and improves associated systemic inflammation in patients with moderate-to-severe atopic dermatitis: results from a randomized double-blind placebo-controlled study. Br J Dermatol 2019; 181:733-742. [PMID: 30919407 PMCID: PMC6850605 DOI: 10.1111/bjd.17932] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2019] [Indexed: 12/30/2022]
Abstract
BACKGROUND ASN002 is an oral dual inhibitor of Janus kinase and spleen tyrosine kinase, which are involved in the pathogenesis of atopic dermatitis (AD) through their regulatory role on T helper (Th)1, Th2 and Th17/Th22 pathways. OBJECTIVES The objectives of this study were to evaluate the efficacy, safety, pharmacokinetics and effects on systemic biomarkers of ASN002 in patients with moderate-to-severe AD. Methods A total of 36 patients with moderate-to-severe AD were randomized (3 : 1) to ASN002 or placebo in the phase Ib study. Three dosage cohorts were studied over a 28-day period (20 mg, 40 mg and 80 mg once daily). RESULTS ASN002 was superior to placebo for the proportion of patients achieving Eczema Area and Severity Index (EASI) 50 (20 mg 20%, P = 0·93; 40 mg 100%, P = 0·003; 80 mg 83%, P = 0·03; placebo 22%), EASI 75 (20 mg 0%, P = 0·27; 40 mg 71%, P = 0·06; 80 mg 33%, P = 0·65; placebo 22%) and in change from baseline in pruritus (20 mg -1·3 ± 2·1, P = 0·81; 40 mg -3·1 ± 2·7, P = 0·27; 80 mg -4·7 ± 2·1, P = 0·01; placebo -1·6 ± 1·8). Adverse events were generally mild and similar across all groups. ASN002 showed dose-dependent plasma exposure with low interpatient variability, significantly downregulated several serum biomarkers involved in Th1, Th2 and Th17/Th22 immunity, and decreased the atherosclerosis-associated biomarker E selectin/SELE. CONCLUSIONS In patients with moderate-to-severe AD, ASN002 showed strong efficacy with rapid onset of action and associated improvements in systemic inflammation.
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Affiliation(s)
- R. Bissonnette
- Innovaderm Research Inc.1851 Sherbrooke Street East, Suite 502MontrealH2K 4L5QuebecCanada
| | - C. Maari
- Innovaderm Research Inc.1851 Sherbrooke Street East, Suite 502MontrealH2K 4L5QuebecCanada
| | - S. Forman
- Forward Clinical Trials, Inc.4915 Ehrlich RoadTampa33624FLU.S.A
| | - N. Bhatia
- Therapeutics Clinical Research9025 Balboa Avenue, Suite 105San Diego92123CAU.S.A
| | - M. Lee
- Progressive Clinical ResearchP.A., LLC1973 North West Loop 410, Suite 106San Antonio78213TXU.S.A
| | - J. Fowler
- Dermatology Specialists Research3810 Springhurst Boulevard, Suite 130Louisville40241KYU.S.A
| | - S. Tyring
- Center for Clinical StudiesUniversity of Texas Health Science Center451 North Texas AvenueHouston77598TXU.S.A
| | - D. Pariser
- Department of DermatologyEastern Virginia Medical School and Virginia Clinical Research Inc.6160 Kempsville Circle, Suite 200ANorfolk23502VAU.S.A
| | - H. Sofen
- Dermatology Research Associates8930 South Sepulveda BoulevardLos Angeles90045CAU.S.A
| | - S. Dhawan
- Center for Dermatology Clinical Research Inc.2557 Mowry Avenue, Suite 21 and 25Fremont94538CAU.S.A
| | - M. Zook
- Olympian Clinical Research1201 South Myrtle AvenueClearwater33756FLU.S.A
| | - D.J. Zammit
- Asana BioSciences, LLC997 Lenox Drive, Suite 220, Princeton Pike Corporate CenterLawrenceville08648NJU.S.A
| | - H. Usansky
- Asana BioSciences, LLC997 Lenox Drive, Suite 220, Princeton Pike Corporate CenterLawrenceville08648NJU.S.A
| | - L. Denis
- Asana BioSciences, LLC997 Lenox Drive, Suite 220, Princeton Pike Corporate CenterLawrenceville08648NJU.S.A
| | - N. Rao
- Asana BioSciences, LLC997 Lenox Drive, Suite 220, Princeton Pike Corporate CenterLawrenceville08648NJU.S.A
| | - T. Song
- Icahn School of Medicine at Mount Sinai1425 Madison Avenue, Icahn Building 13‐76New York10029NYU.S.A
| | - A.B. Pavel
- Icahn School of Medicine at Mount Sinai1425 Madison Avenue, Icahn Building 13‐76New York10029NYU.S.A
| | - E. Guttman‐Yassky
- Icahn School of Medicine at Mount Sinai1425 Madison Avenue, Icahn Building 13‐76New York10029NYU.S.A
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Bissonnette R, Maari C, Forman S, Bhatia N, Lee M, Fowler J, Tyring S, Pariser D, Sofen H, Dhawan S, Zook M, Zammit D, Usansky H, Denis L, Rao N, Song T, Pavel A, Guttman‐Yassky E. ASN002 demonstrates efficacy and improves inflammation in AD. Br J Dermatol 2019. [DOI: 10.1111/bjd.18398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Zook M, Barocas S, boyd D, Crawford K, Keller E, Gangadharan SP, Goodman A, Hollander R, Koenig BA, Metcalf J, Narayanan A, Nelson A, Pasquale F. Ten simple rules for responsible big data research. PLoS Comput Biol 2017; 13:e1005399. [PMID: 28358831 PMCID: PMC5373508 DOI: 10.1371/journal.pcbi.1005399] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Matthew Zook
- Department of Geography, University of Kentucky, Lexington, Kentucky, United States of America
- * E-mail:
| | - Solon Barocas
- Microsoft Research, New York, New York, United States of America
| | - danah boyd
- Microsoft Research, New York, New York, United States of America
- Data & Society, New York, New York, United States of America
| | - Kate Crawford
- Microsoft Research, New York, New York, United States of America
- Information Law Institute, New York University, New York, New York, United States of America
| | - Emily Keller
- Data & Society, New York, New York, United States of America
| | - Seeta Peña Gangadharan
- Department of Media and Communications, London School of Economics, London, United Kingdom
| | - Alyssa Goodman
- Harvard-Smithsonian Center for Astrophysics, Harvard University, Cambridge, Massachusetts, United States of America
| | - Rachelle Hollander
- Center for Engineering Ethics and Society, National Academy of Engineering, Washington, DC, United States of America
| | - Barbara A. Koenig
- Institute for Health Aging, University of California-San Francisco, San Francisco, California, United States of America
| | - Jacob Metcalf
- Ethical Resolve, Santa Cruz, California, United States of America
| | - Arvind Narayanan
- Department of Computer Science, Princeton University, Princeton, New Jersey, United States of America
| | - Alondra Nelson
- Department of Sociology, Columbia University, New York, New York, United States of America
| | - Frank Pasquale
- Carey School of Law, University of Maryland, Baltimore, Maryland, United States of America
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Robinson T, Zook M, Goodenough E, Nelson C, Flanigan K, Atkins J, Howard M, Eisenlohr L. Aminoglycoside-induced readthrough of stop codons in vivo elicits presentation of novel immunogenic MHC class I epitopes . (106.39). The Journal of Immunology 2012. [DOI: 10.4049/jimmunol.188.supp.106.39] [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] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Aminoglycoside antibiotics are known to induce stop codon readthrough in eukaryotic cells, and thus hold potential for the treatment of genetic diseases caused by nonsense mutations. A potential consequence of aminoglycoside treatment is the translation of 3’ noncoding regions and generation of major histocompatibiltiy complex (MHC)-restricted neoepitopes, a potential cause of autoimmune reactivity. Here we explored the impact of aminoglycoside-induced readthough on the production of MHC class I binding peptides. Firstly, we developed a panel of recombinant vaccinia viruses in which expression of a MHC class I binding peptide depends upon stop codon readthrough. Both in vitro and in vivo studies indicated that gentamicin induces activating levels of epitope with the magnitude of the response strongly influenced by identity of the stop codon and the surrounding context in agreement with a previously determined hierarchy. Secondly, we treated uninfected cells with gentamicin to assess the level of aminoglycoside-induced readthrough on native stop codons. HPLC analysis revealed a small number of differences in the peak profiles. Further analysis will be done with mass spectrometry to determine the identity of these epitopes, and where they are located in the mouse genome. The data from these and future studies can be used determine the extent to which stop codon readthrough occurs, and the implications for eliciting autoimmunity.
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Affiliation(s)
- Tara Robinson
- 1Dept. of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, PA
| | - Matthew Zook
- 2Dept. of Dermatology, Fox Chase Cancer Center, Philadelphia, PA
| | - Elliot Goodenough
- 1Dept. of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, PA
| | - Chad Nelson
- 3Dept. of Genetics, University of Utah Sch. of Med., Philadelphia, UT
| | - Kevin Flanigan
- 4Center for Gene Therapy, Nationwide Children's Hospital, Columbus, OH
| | - John Atkins
- 3Dept. of Genetics, University of Utah Sch. of Med., Philadelphia, UT
| | - Michael Howard
- 3Dept. of Genetics, University of Utah Sch. of Med., Philadelphia, UT
| | - Laurence Eisenlohr
- 1Dept. of Microbiology and Immunology, Thomas Jefferson University, Philadelphia, PA
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Pearlman JM, Prawer SP, Barber MT, Parkinson SJ, Schulz S, Park J, Zook M, Waldman SA. A splice variant of the transcript for guanylyl cyclase C is expressed in human colon and colorectal cancer cells. Dig Dis Sci 2000; 45:298-305. [PMID: 10711442 DOI: 10.1023/a:1005456408768] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
Guanylyl cyclase C is a sensitive and specific biomarker for metastatic colorectal cancer. A variant of the guanylyl cyclase C transcript was identified that possesses a 142-bp deletion at the 3' end of exon 1 reflecting alternative splicing of mRNA, introducing a shift in the open reading frame that prevents translation of a guanylyl cyclase C-related product. This variant was identified in human intestine and colon carcinomas, but not in extraintestinal tissues or tumors. These studies demonstrate that GCC and the splice variant contribute to the pool of GCC transcripts detected by RT-PCR in human tissues. They indicate that primers for RT-PCR that amplify regions downstream from the deletion are required to assess the full complement of GCC transcripts (GCC + GCC(var)) in human tissues and body fluids for staging and postoperative surveillance of patients with colorectal cancer.
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Affiliation(s)
- J M Pearlman
- Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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Abstract
Inoculation of leaves of Arabis lyrata with either a bacterial pathogen Pseudomonas syringae pv. maculicola strain ES4326 or Cochliobolus carbonum, a fungal nonpathogen of A. lyrata, resulted in the accumulation of a compound with similar chromatographic and fluorescent properties to that of camalexin (I), a phytoalexin produced by Arabidopsis thaliana. A. lyrata is closely related to A. thaliana. High resolution electron impact mass spectroscopic and proton NMR analysis confirmed that the compound produced by A. lyrata is camalexin.
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Affiliation(s)
- M Zook
- Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824, USA
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Zook M. Biosynthesis of camalexin from tryptophan pathway intermediates in cell-suspension cultures of Arabidopsis. Plant Physiol 1998; 118:1389-93. [PMID: 9847113 PMCID: PMC34755 DOI: 10.1104/pp.118.4.1389] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/1998] [Accepted: 09/14/1998] [Indexed: 05/19/2023]
Abstract
Camalexin (3-thiazol-2'-yl-indole) is the principal phytoalexin that accumulates in Arabidopsis after infection by fungi or bacteria. Camalexin accumulation was detectable in Arabidopsis cell-suspension cultures 3 to 5 h after inoculation with Cochliobolus carbonum (Race 1), and then increased rapidly from 7 to 24 h after inoculation. Levels of radioactivity incorporated into camalexin during a 1.5-h pulse labeling with [14C]anthranilate also increased with time after fungal inoculation. The levels of radioactive incorporation into camalexin increased rapidly between 7 and 18 h after inoculation, and then decreased along with camalexin accumulation. Relatively low levels of radioactivity from [14C]anthranilate incorporated into camalexin in the noninoculated controls. Autoradiographic analysis of the accumulation of chloroform-extractable metabolites labeled with [14C]anthranilate revealed a transient increase in the incorporation of radioactivity into indole in fungus-inoculated Arabidopsis cell cultures. The time-course measurement of radioactive incorporation into camalexin during a 1.5-h pulse labeling with [14C]indole was similar to that with [14C]anthranilate. These data suggest that indole destined for camalexin synthesis is produced by a separate enzymatic reaction that does not involve tryptophan synthase.
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Affiliation(s)
- M Zook
- Department of Botany and Plant Pathology, Michigan State University, East Lansing, Michigan 48824, USA.
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Glazebrook J, Zook M, Mert F, Kagan I, Rogers EE, Crute IR, Holub EB, Hammerschmidt R, Ausubel FM. Phytoalexin-deficient mutants of Arabidopsis reveal that PAD4 encodes a regulatory factor and that four PAD genes contribute to downy mildew resistance. Genetics 1997; 146:381-92. [PMID: 9136026 PMCID: PMC1207952 DOI: 10.1093/genetics/146.1.381] [Citation(s) in RCA: 287] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We are working to determine the role of the Arabidopsis phytoalexin, camalexin, in protecting the plant from pathogen attack by isolating phytoalexin-deficient (pad) mutants in the accession Columbia (Col-0) and examining their response to pathogens. Mutations in PAD1, PAD2, and PAD4 caused enhanced susceptibility to the bacterial pathogen Pseudomonas syringae pv. maculicola strain ES4326 (PsmES4326), while mutations in PAD3 or PAD5 did not. Camalexin was not detected in any of the double mutants pad1-1 pad2-1, pad1-1 pad3-1 or pad2-1 pad3-1. Growth of PsmES4326 in pad1-1 pad2-1 was greater than that in pad1-1 or pad2-1 plants, while growth in pad1-1 pad3-1 and pad2-1 pad3-1 plants was similar to that in pad1-1 and pad2-1 plants, respectively. The pad4-1 mutation caused reduced camalexin synthesis in response to PsmES4326 infection, but not in response to Cochliobolus carbonum infection, indicating that PAD4 has a regulatory function. PAD1, PAD2, PAD3 and PAD4 are all required for resistance to the eukaryotic biotroph Peronospora parasitica. The pad4-1 mutation caused the most dramatic change, exhibiting full susceptibility to four of six Col-incompatible parasite isolates. Interestingly, each combination of double mutants between pad1-1, pad2-1 and pad3-1 exhibited additive shifts to moderate or full susceptibility to most of the isolates.
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Affiliation(s)
- J Glazebrook
- Center for Agricultural Biotechnology, University of Maryland Biotechnology Institute, College Park 20742, USA.
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Abstract
The principal phytoalexin that accumulates in Arabidopsis thaliana after infection by fungi or bacteria is 3-thiazol-2'-yl-indole (camalexin). Detached noninoculated leaves of Arabidopsis and leaves inoculated with the fungus Cochliobolus carbonum were fed [35S]cysteine (Cys) and [35S]methionine. Inoculated leaves incorporated more than a 200-fold greater amount of radioactivity from [35S]Cys into camalexin, as compared with noninoculated leaves. The amount of radioactivity from [35S]Cys that was incorporated into camalexin from inoculated Arabidopsis leaves was 10-fold greater than the amount of radioactivity that was incorporated into camalexin from [35S]methionine. Additional labeling experiments were performed to determine whether other atoms of Cys are incorporated into camalexin. [14C]Cys and [35S]Cys were incorporated into camalexin with approximately the same efficiency. Cys labeled either with deuterium (D3-Cys[2,3,3]) or 13C and 15N ([U-13C,15N]Cys) was also fed to inoculated leaves of Arabidopsis; camalexin was analyzed by mass spectroscopic analysis. The average ratio of molecular ion intensities of 203/200 for [U-13C,15N]Cys-labeled camalexin was 4.22, as compared with 0.607 for the average 203/200 ratio for unlabeled camalexin. The mass fragment-ion intensity ratios of 60/58 (thiazole ring ion fragment) and 143/142 were also higher for [U-13C,15N]Cys-labeled camalexin, as compared with unlabeled camalexin. The 59/58 and 201/200 ratios were higher for D3-Cys-labeled camalexin as compared with unlabeled camalexin. These data are consistent with the predicted formation of the thiazole ring of camalexin from Cys.
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Affiliation(s)
- M Zook
- Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824, USA.
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Zook M, Johnson K, Hohn T, Hammerschmidt R. Structural characterization of 15-hydroxytrichodiene, a sesquiterpenoid produced by transformed tobacco cell suspension cultures expressing a trichodiene synthase gene from Fusarium sporotrichioides. Phytochemistry 1996; 43:1235-7. [PMID: 8987907 DOI: 10.1016/s0031-9422(96)00382-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Tobacco (Nicotiana tabaccum) cell suspension cultures transformed with a gene encoding trichodiene synthase, a sesquiterpene synthase from the fungus Fusarium sporotrichioides, produced a novel sesquiterpenoid derived from the in vivo production of trichodiene. Mass and nuclear magnetic resonance spectroscopic analyses identified the new compound as 15-hydroxytrichodiene. The in vivo hydroxylation of trichodiene by transformant tobacco cell suspension cultures demonstrates that the introduction of a foreign sesquiterpene synthase gene can result in the production of novel sesquiterpenoid metabolites.
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Affiliation(s)
- M Zook
- Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824, USA
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Zook M, Hohn T, Bonnen A, Tsuji J, Hammerschmidt R. Characterization of Novel Sesquiterpenoid Biosynthesis in Tobacco Expressing a Fungal Sesquiterpene Synthase. Plant Physiol 1996; 112:311-318. [PMID: 12226394 PMCID: PMC157951 DOI: 10.1104/pp.112.1.311] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The gene encoding trichodiene synthase (Tri5), a sesquiterpene synthase from the fungus Fusarium sporotrichioides, was used to transform tobacco (Nicotiana tabacum). Trichodiene was the sole sesquiterpene synthase product in enzyme reaction mixtures derived from unelicited transformant cell-suspension cultures, and both trichodiene and 5-epi-aristolochene were observed as reaction products following elicitor treatment. Immunoblot analysis of protein extracts revealed the presence of trichodiene synthase only in transformant cell lines producing trichodiene. In vivo labeling with [3H]mevalonate revealed the presence of a novel trichodiene metabolite, 15-hydroxytrichodiene, that accumulated in the transformant cell-suspension cultures. In a trichodiene-producing transformant, the level of 15-hydroxytrichodiene accumulation increased after elicitor treatment. In vivo labeling with [14C]acetate showed that the biosynthetic rate of trichodiene and 15-hydroxytrichodiene also increased after elicitor treatment. Incorporation of radioactivity from [14C]acetate into capsidiol was reduced following elicitor treatment of a trichodiene-producing transformant as compared with wild type. These results demonstrate that sesquiterpenoid accumulation resulting from the constitutive expression of a foreign sesquiterpene synthase is responsive to elicitation and that the farnesyl pyrophosphate present in elicited cells can be utilized by a foreign sesquiterpene synthase to produce high levels of novel sesquiterpenoids.
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Affiliation(s)
- M. Zook
- Department of Botany and Plant Pathology, Michigan State University, East Lansing, Michigan 48824 (M.Z., A.B., J.T., R.H.)
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