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Butler P, Pascheto I, Lizzi M, St-Onge R, Lanner C, Guo B, Masilamani T, Pritzker LB, Kovala AT, Parissenti AM. RNA disruption is a widespread phenomenon associated with stress-induced cell death in tumour cells. Sci Rep 2023; 13:1711. [PMID: 36720913 PMCID: PMC9889758 DOI: 10.1038/s41598-023-28635-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Accepted: 01/23/2023] [Indexed: 02/01/2023] Open
Abstract
We have previously shown that neoadjuvant chemotherapy can induce the degradation of tumour ribosomal RNA (rRNA) in patients with advanced breast cancer, a phenomenon we termed "RNA disruption". Extensive tumour RNA disruption during chemotherapy was associated with a post-treatment pathological complete response and improved disease-free survival. The RNA disruption assay (RDA), which quantifies this phenomenon, is now being evaluated for its clinical utility in a large multinational clinical trial. However, it remains unclear if RNA disruption (i) is manifested across many tumour and non-tumour cell types, (ii) can occur in response to cell stress, and (iii) is associated with tumour cell death. In this study, we show that RNA disruption is induced by several mechanistically distinct chemotherapy agents and report that this phenomenon is observed in response to oxidative stress, endoplasmic reticulum (ER) stress, protein translation inhibition and nutrient/growth factor limitation. We further show that RNA disruption is dose- and time-dependent, and occurs in both tumourigenic and non-tumourigenic cell types. Northern blotting experiments suggest that the rRNA fragments generated during RNA disruption stem (at least in part) from the 28S rRNA. Moreover, we demonstrate that RNA disruption is reproducibly associated with three robust biomarkers of cell death: strongly reduced cell numbers, lost cell replicative capacity, and the generation of cells with a subG1 DNA content. Thus, our findings indicate that RNA disruption is a widespread phenomenon exhibited in mammalian cells under stress, and that high RNA disruption is associated with the onset of cell death.
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Affiliation(s)
- Phillipe Butler
- Graduate Program in Chemical Sciences, Laurentian University, Sudbury, ON, Canada
| | - Isabella Pascheto
- Graduate Program in Chemical Sciences, Laurentian University, Sudbury, ON, Canada
| | - Michayla Lizzi
- Graduate Program in Chemical Sciences, Laurentian University, Sudbury, ON, Canada
| | - Renée St-Onge
- Rna Diagnostics, Inc., Sudbury, ON, Canada.,Rna Diagnostics, Inc., Toronto, ON, Canada
| | - Carita Lanner
- Graduate Program in Chemical Sciences, Laurentian University, Sudbury, ON, Canada.,Division of Medical Sciences, Northern Ontario School of Medicine, Sudbury, ON, Canada
| | - Baoqing Guo
- Health Sciences North Research Institute, Sudbury, ON, Canada
| | - Twinkle Masilamani
- Rna Diagnostics, Inc., Sudbury, ON, Canada.,Rna Diagnostics, Inc., Toronto, ON, Canada
| | - Laura B Pritzker
- Rna Diagnostics, Inc., Sudbury, ON, Canada.,Rna Diagnostics, Inc., Toronto, ON, Canada
| | - A Thomas Kovala
- Graduate Program in Chemical Sciences, Laurentian University, Sudbury, ON, Canada.,Division of Medical Sciences, Northern Ontario School of Medicine, Sudbury, ON, Canada
| | - Amadeo M Parissenti
- Graduate Program in Chemical Sciences, Laurentian University, Sudbury, ON, Canada. .,Rna Diagnostics, Inc., Sudbury, ON, Canada. .,Rna Diagnostics, Inc., Toronto, ON, Canada. .,Health Sciences North Research Institute, Sudbury, ON, Canada. .,Division of Medical Sciences, Northern Ontario School of Medicine, Sudbury, ON, Canada.
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2
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Zhang X, Wang X, Li Q, Chen Y, Zhang X, Wang P, Yuan M, Pei H. [Role of PNPT1 in cardiomyocyte apoptosis induced by oxygen-glucose deprivation]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2022; 42:584-590. [PMID: 35527495 DOI: 10.12122/j.issn.1673-4254.2022.04.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To explore the effect of inhibiting polyribonucleotide nucleotidyl-transferase 1 (PNPT1) on oxygen-glucose deprivation (OGD)-induced apoptosis of mouse atrial myocytes. METHODS Cultured mouse atrial myocytes (HL-1 cells) with or without OGD were transfected with PNPT1-siRNA or a negative control siRNA (NC-siRNA group), and the cell survival rate was detected using CCK-8 assay. The expression levels of ACTB and TUBA mRNA were detected with qPCR, and the protein expression of PNPT1 was detected with Western blotting. The apoptosis rate of the treated cells was determined with flow cytometry, the mitochondrial membrane potential was detected using JC-1 kit, and the mitochondrial morphology was observed using transmission electron microscope. RESULTS With the extension of OGD time, the protein expression levels of PNPT1 increased progressively in the cytoplasm of HL-1 cells (P < 0.05). Transfection with PNPT1-siRNA significantly reduced PNPT1 expression in HL-1 cells (P < 0.05). Exposure to OGD significantly enhanced degradation of ACTB and TUBA mRNA (P < 0.05) and markedly increased the apoptosis rate of HL-1 cells (P < 0.05), and these changes were significantly inhibited by transfection with PNPT1-siRNA (P < 0.05), which obviously increased mitochondrial membrane potential and improved mitochondrial morphology of HL-1 cells exposed to OGD. CONCLUSION Inhibition of PNPT1 improves mitochondrial damage and reduces degradation of apoptotic-associated mRNAs to alleviate OGD-induced apoptosis of mouse atrial myocyte.
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Affiliation(s)
- X Zhang
- College of Medicine, Southwest Jiaotong University, Chengdu 611756, China.,Department of Cardiology, General Hospital of Western Theater Command, Chengdu 610083, China
| | - X Wang
- Department of Cardiology, General Hospital of Western Theater Command, Chengdu 610083, China
| | - Q Li
- Second Ward of Cadres, General Hospital of Western Theater Command, Chengdu 610083, China
| | - Y Chen
- Department of Cardiology, General Hospital of Western Theater Command, Chengdu 610083, China
| | - X Zhang
- Medical Information Data Office, General Hospital of Western Theater Command, Chengdu 610083, China
| | - P Wang
- Department of Cardiology, General Hospital of Western Theater Command, Chengdu 610083, China
| | - M Yuan
- Medical Center, General Hospital of Western Theater Command, Chengdu 610083, China
| | - H Pei
- College of Medicine, Southwest Jiaotong University, Chengdu 611756, China.,Department of Cardiology, General Hospital of Western Theater Command, Chengdu 610083, China
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Tokmakov AA, Iguchi S, Iwasaki T, Fukami Y, Sato KI. Global decay of mRNA is a hallmark of apoptosis in aging Xenopus eggs. RNA Biol 2017; 14:339-346. [PMID: 28045588 PMCID: PMC5367254 DOI: 10.1080/15476286.2016.1276695] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Cytoplasmic mRNAs are specifically degraded in somatic cells as a part of early apoptotic response. However, no reports have been presented so far concerning mRNA fate in apoptotic gametes. In the present study, we analyzed the content of various cytoplasmic mRNAs in aging oocytes and eggs of the African clawed frog, Xenopus laevis. To circumvent large gene expression variation among the individual oocytes and eggs, single-cell monitoring of transcript levels has been implemented, using multiple cytoplasmic collections and reverse transcriptase quantitative PCR. It was found that numerous cytoplasmic mRNAs, coding for proteins classified in different functional types, are robustly degraded in apoptotic Xenopus eggs, but not in aging oocytes. mRNA degradation becomes evident in the eggs after meiotic exit at the time of cytochrome c release. A strong correlation between the length of PCR amplicon and specific transcript content was observed, suggesting endonucleolytic cleavage of mRNA. In addition, it was found that mRNA deadenylation also contributes to apoptotic mRNA degradation. Altogether, these findings indicate that the global decay of mRNA represents a hallmark of apoptosis in aging Xenopus eggs. To our knowledge, this is the first description of mRNA degradation in apoptotic gamete cells.
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Affiliation(s)
- Alexander A Tokmakov
- a Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo Motoyama , Kita ku , Kyoto , Japan.,b Graduate School of Science, Kobe University, Rokko dai , Nada , Kobe , Japan
| | - Sho Iguchi
- b Graduate School of Science, Kobe University, Rokko dai , Nada , Kobe , Japan
| | - Tetsushi Iwasaki
- b Graduate School of Science, Kobe University, Rokko dai , Nada , Kobe , Japan
| | - Yasuo Fukami
- b Graduate School of Science, Kobe University, Rokko dai , Nada , Kobe , Japan
| | - Ken-Ichi Sato
- a Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo Motoyama , Kita ku , Kyoto , Japan
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4
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Narendrula R, Mispel-Beyer K, Guo B, Parissenti AM, Pritzker LB, Pritzker K, Masilamani T, Wang X, Lannér C. RNA disruption is associated with response to multiple classes of chemotherapy drugs in tumor cell lines. BMC Cancer 2016; 16:146. [PMID: 26911141 PMCID: PMC4765116 DOI: 10.1186/s12885-016-2197-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Accepted: 02/17/2016] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Cellular stressors and apoptosis-inducing agents have been shown to induce ribosomal RNA (rRNA) degradation in eukaryotic cells. Recently, RNA degradation in vivo was observed in patients with locally advanced breast cancer, where mid-treatment tumor RNA degradation was associated with complete tumor destruction and enhanced patient survival. However, it is not clear how widespread chemotherapy induced "RNA disruption" is, the extent to which it is associated with drug response or what the underlying mechanisms are. METHODS Ovarian (A2780, CaOV3) and breast (MDA-MB-231, MCF-7, BT474, SKBR3) cancer cell lines were treated with several cytotoxic chemotherapy drugs and total RNA was isolated. RNA was also prepared from docetaxel resistant A2780DXL and carboplatin resistant A2780CBN cells following drug exposure. Disruption of RNA was analyzed by capillary electrophoresis. Northern blotting was performed using probes complementary to the 28S and 18S rRNA to determine the origins of degradation bands. Apoptosis activation was assessed by flow cytometric monitoring of annexin-V and propidium iodide (PI) binding to cells and by measuring caspase-3 activation. The link between apoptosis and RNA degradation (disruption) was investigated using a caspase-3 inhibitor. RESULTS All chemotherapy drugs tested were capable of inducing similar RNA disruption patterns. Docetaxel treatment of the resistant A2780DXL cells and carboplatin treatment of the A2780CBN cells did not result in RNA disruption. Northern blotting indicated that two RNA disruption bands were derived from the 3'-end of the 28S rRNA. Annexin-V and PI staining of docetaxel treated cells, along with assessment of caspase-3 activation, showed concurrent initiation of apoptosis and RNA disruption, while inhibition of caspase-3 activity significantly reduced RNA disruption. CONCLUSIONS Supporting the in vivo evidence, our results demonstrate that RNA disruption is induced by multiple chemotherapy agents in cell lines from different tissues and is associated with drug response. Although present, the link between apoptosis and RNA disruption is not completely understood. Evaluation of RNA disruption is thus proposed as a novel and effective biomarker to assess response to chemotherapy drugs in vitro and in vivo.
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MESH Headings
- Antineoplastic Agents/pharmacology
- Apoptosis
- Breast Neoplasms/drug therapy
- Breast Neoplasms/genetics
- Carboplatin/pharmacology
- Caspase 3/metabolism
- Cell Line, Tumor
- Docetaxel
- Dose-Response Relationship, Drug
- Drug Resistance, Neoplasm
- Female
- Humans
- MCF-7 Cells
- Ovarian Neoplasms/drug therapy
- Ovarian Neoplasms/genetics
- RNA Stability/drug effects
- RNA, Ribosomal, 18S/chemistry
- RNA, Ribosomal, 18S/genetics
- RNA, Ribosomal, 28S/chemistry
- RNA, Ribosomal, 28S/genetics
- Taxoids/pharmacology
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Affiliation(s)
| | - Kyle Mispel-Beyer
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON, Canada
| | - Baoqing Guo
- Advanced Medical Research Institute of Canada, Sudbury, ON, Canada
- RNA Diagnostics Inc., Toronto, ON, Canada
| | - Amadeo M Parissenti
- Department of Biology, Laurentian University, Sudbury, ON, Canada
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON, Canada
- Division of Medical Sciences, Northern Ontario School of Medicine, 935 Ramsey Lake Rd., Sudbury, ON, P3E 2C6, Canada
- Advanced Medical Research Institute of Canada, Sudbury, ON, Canada
- Faculty of Medicine, Division of Oncology, University of Ottawa, Ottawa, ON, Canada
- RNA Diagnostics Inc., Toronto, ON, Canada
| | | | | | | | | | - Carita Lannér
- Department of Biology, Laurentian University, Sudbury, ON, Canada.
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON, Canada.
- Division of Medical Sciences, Northern Ontario School of Medicine, 935 Ramsey Lake Rd., Sudbury, ON, P3E 2C6, Canada.
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5
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Takamatsu K, Iehisa JCM, Nishijima R, Takumi S. Comparison of gene expression profiles and responses to zinc chloride among inter- and intraspecific hybrids with growth abnormalities in wheat and its relatives. PLANT MOLECULAR BIOLOGY 2015; 88:487-502. [PMID: 26081164 DOI: 10.1007/s11103-015-0338-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 06/09/2015] [Indexed: 06/04/2023]
Abstract
Hybrid necrosis is a well-known reproductive isolation mechanism in plant species, and an autoimmune response is generally considered to trigger hybrid necrosis through epistatic interaction between disease resistance-related genes in hybrids. In common wheat, the complementary Ne1 and Ne2 genes control hybrid necrosis, defined as type I necrosis. Two other types of hybrid necrosis (type II and type III) have been observed in interspecific hybrids between tetraploid wheat and Aegilops tauschii. Another type of hybrid necrosis, defined here as type IV necrosis, has been reported in F1 hybrids between Triticum urartu and some accessions of Triticum monococcum ssp. aegilopoides. In types I, III and IV, cell death occurs gradually starting in older tissues, whereas type II necrosis symptoms occur only under low temperature. To compare comprehensive gene expression patterns of hybrids showing growth abnormalities, transcriptome analysis of type I and type IV necrosis was performed using a wheat 38k oligo-DNA microarray. Defense-related genes including many WRKY transcription factor genes were dramatically up-regulated in plants showing type I and type IV necrosis, similarly to other known hybrid abnormalities, suggesting an association with an autoimmune response. Reactive oxygen species generation and necrotic cell death were effectively inhibited by ZnCl2 treatment in types I, III and IV necrosis, suggesting a significant association of Ca(2+) influx in upstream signaling of necrotic cell death in wheat hybrid necrosis.
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Affiliation(s)
- Kiyofumi Takamatsu
- Laboratory of Plant Genetics, Graduate School of Agricultural Science, Kobe University, Rokkodai 1-1, Nada, Kobe, 657-8501, Japan
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6
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Tokmakov AA, Hashimoto T, Hasegawa Y, Iguchi S, Iwasaki T, Fukami Y. Monitoring gene expression in a single Xenopus oocyte using multiple cytoplasmic collections and quantitative RT-PCR. FEBS J 2013; 281:104-14. [PMID: 24165194 DOI: 10.1111/febs.12576] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 10/10/2013] [Accepted: 10/21/2013] [Indexed: 11/27/2022]
Abstract
Oocytes and eggs of the African clawed frog, Xenopus laevis, are commonly used in gene expression studies. However, monitoring transcript levels in the individual living oocytes remains challenging. To address this challenge, we used a technique based on multiple repeated collections of nanoliter volumes of cytoplasmic material from a single oocyte. Transcript quantification was performed by quantitative RT-PCR. The technique allowed monitoring of heterologous gene expression in a single oocyte without affecting its viability. We also used this approach to profile the expression of endogenous genes in living Xenopus oocytes. Although frog oocytes are traditionally viewed as a homogenous cell population, a significant degree of gene expression variation was observed among the individual oocytes. A lognormal distribution of transcript levels was revealed in the oocyte population. Finally, using this technique, we observed a dramatic decrease in the content of various cytoplasmic mRNAs in aging unfertilized eggs but not in oocytes, suggesting a link between mRNA degradation and egg apoptosis.
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7
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Maiväli Ü, Paier A, Tenson T. When stable RNA becomes unstable: the degradation of ribosomes in bacteria and beyond. Biol Chem 2013; 394:845-55. [PMID: 23612597 DOI: 10.1515/hsz-2013-0133] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Accepted: 03/20/2013] [Indexed: 11/15/2022]
Abstract
This review takes a comparative look at the various scenarios where ribosomes are degraded in bacteria and eukaryotes with emphasis on studies involving Escherichia coli and Saccharomyces cerevisiae. While the molecular mechanisms of degradation in bacteria and yeast appear somewhat different, we argue that the underlying causes of ribosome degradation are remarkably similar. In both model organisms during ribosomal assembly, partially formed pre-ribosomal particles can be degraded by at least two different sequentially-acting quality control pathways and fully assembled but functionally faulty ribosomes can be degraded in a separate quality control pathway. In addition, ribosomes that are both structurally- and functionally-sound can be degraded as an adaptive measure to stress.
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Affiliation(s)
- Ülo Maiväli
- Institute of Technology, University of Tartu, Nooruse 1, Tartu 50411, Estonia.
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8
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Hoat TX, Nakayashiki H, Yang Q, Tosa Y, Mayama S. Molecular cloning of the apoptosis-related calcium-binding protein AsALG-2 in Avena sativa. MOLECULAR PLANT PATHOLOGY 2013; 14:222-9. [PMID: 23083467 PMCID: PMC6638752 DOI: 10.1111/j.1364-3703.2012.00844.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Victorin, the host-selective toxin produced by the fungus Cochliobolus victoriae, induces programmed cell death (PCD) in victorin-sensitive oat lines with characteristic features of animal apoptosis, such as mitochondrial permeability transition, chromatin condensation, nuclear DNA laddering and rRNA/mRNA degradation. In this study, we characterized a calcium-binding protein, namely AsALG-2, which might have a role in the victorin-induced PCD. AsALG-2 is homologous to the Apoptosis-Linked Gene ALG-2 identified in mammalian cells. Northern blot analysis revealed that the accumulation of AsALG-2 transcripts increased during victorin-induced PCD, but not during necrotic cell death. Salicylic acid, chitosan and chitin strongly activated the expression of general defence response genes, such as PR-10; however, neither induced cell death nor the accumulation of AsALG-2 mRNA. Pharmacological studies indicated that victorin-induced DNA laddering and AsALG-2 expression were regulated through similar pathways. The calcium channel blocker, nifedipine, moderately inhibited the accumulation of AsALG-2 mRNA during cell death. Trifluoperazine (calmodulin antagonist) and K252a (serine-threonine kinase inhibitor) reduced the victorin-induced phytoalexin accumulation, but did not prevent the victorin-induced DNA laddering or accumulation of AsALG-2 mRNA. Taken together, our investigations suggest that there is a calcium-mediated signalling pathway in animal and plant PCD in common.
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Affiliation(s)
- Trinh Xuan Hoat
- Laboratory of Plant Pathology, Graduate School of Science and Technology, Kobe University, Rokkodai, Nada-ku, Kobe, Japan.
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Horbach R, Navarro-Quesada AR, Knogge W, Deising HB. When and how to kill a plant cell: infection strategies of plant pathogenic fungi. JOURNAL OF PLANT PHYSIOLOGY 2011; 168:51-62. [PMID: 20674079 DOI: 10.1016/j.jplph.2010.06.014] [Citation(s) in RCA: 203] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 06/16/2010] [Accepted: 06/18/2010] [Indexed: 05/23/2023]
Abstract
Fungi cause severe diseases on a broad range of crop and ornamental plants, leading to significant economical losses. Plant pathogenic fungi exhibit a huge variability in their mode of infection, differentiation and function of infection structures and nutritional strategy. In this review, advances in understanding mechanisms of biotrophy, necrotrophy and hemibiotrophic lifestyles are described. Special emphasis is given to the biotrophy-necrotrophy switch of hemibiotrophic pathogens, and to biosynthesis, chemical diversity and mode of action of various fungal toxins produced during the infection process.
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Affiliation(s)
- Ralf Horbach
- Martin-Luther-University Halle-Wittenberg, Faculty of Natural Sciences III, Institute for Agricultural and Nutritional Sciences, Phytopathology and Plant Protection, Betty-Heimann-Strasse 3, Halle (Saale), Germany
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10
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Wijayanto T, Barker SJ, Wylie SJ, Gilchrist DG, Cowling WA. Significant reduction of fungal disease symptoms in transgenic lupin (Lupinus angustifolius) expressing the anti-apoptotic baculovirus gene p35. PLANT BIOTECHNOLOGY JOURNAL 2009; 7:778-790. [PMID: 19754837 DOI: 10.1111/j.1467-7652.2009.00443.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Narrow-leafed lupin (NLL; Lupinus angustifolius) is a recently domesticated but anciently propagated crop with significant value in rotation with cereals in Mediterranean climates. However, several fungal pathogens, traditionally termed necrotrophs, severely affect broad-acre production and there is limited genetic resistance in the NLL germplasm pool. Symptoms of many of these diseases appear as localized areas of dead cells exhibiting markers of programmed cell death. Based on our previous research, we hypothesized that engineered expression of the baculovirus anti-apoptotic p35 gene might reduce symptoms of these diseases. Using Agrobacterium tumefaciens-mediated transformation of a cultivar highly susceptible to several pathogens, 14 independent NLL lines containing both the p35 and bar genes were obtained (p35-NLL). Integration and expression of the transgenes were confirmed by polymerase chain reaction (PCR), progeny testing, Southern blot, Northern blot and reverse transcriptase-PCR analyses. Fecundity and nodulation were not altered in these lines. Third or fourth generation p35-NLL lines were challenged with necrotrophic fungal pathogens (anthracnose in stem and leaf, and Pleiochaeta root rot and leaf brown spot) in controlled environment conditions. Several p35-NLL lines had significantly reduced disease symptoms. Interestingly, as with natural resistance, no single line was improved for all three diseases which possibly reflecting spatial variation of p35 expression in planta. These data support an alternative molecular definition for 'necrotrophic disease' in plants and suggest new routes for achieving resistance against a range of pathogens.
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Affiliation(s)
- Teguh Wijayanto
- School of Plant Biology M084, The University of Western Australia, Crawley, WA, Australia
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11
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Reich CF, Pisetsky DS. The content of DNA and RNA in microparticles released by Jurkat and HL-60 cells undergoing in vitro apoptosis. Exp Cell Res 2008; 315:760-8. [PMID: 19146850 DOI: 10.1016/j.yexcr.2008.12.014] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2008] [Revised: 12/09/2008] [Accepted: 12/11/2008] [Indexed: 12/21/2022]
Abstract
Microparticles are small membrane-bound vesicles that are released from apoptotic cells during blebbing. These particles contain DNA and RNA and display important functional activities, including immune system activation. Furthermore, nucleic acids inside the particle can be analyzed as biomarkers in a variety of disease states. To elucidate the nature of microparticle nucleic acids, DNA and RNA released in microparticles from the Jurkat T and HL-60 promyelocytic cell lines undergoing apoptosis in vitro were studied. Microparticles were isolated from culture media by differential centrifugation and characterized by flow cytometry and molecular approaches. In these particles, DNA showed laddering by gel electrophoresis and was present in a form that allowed direct binding by a monoclonal anti-DNA antibody, suggesting antigen accessibility even without fixation. Analysis of RNA by gel electrophoresis showed intact 18s and 28s ribosomal RNA bands, although lower molecular bands consistent with 28s ribosomal RNA degradation products were also present. Particles also contained messenger RNA as shown by RT-PCR amplification of sequences for beta-actin and GAPDH. In addition, gel electrophoresis showed the presence of low molecular weight RNA in the size range of microRNA. Together, these results indicate that microparticles from apoptotic Jurkat and HL-60 cells contain diverse nucleic acid species, indicating translocation of both nuclear and cytoplasmic DNA and RNA as particle release occurs during death.
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Affiliation(s)
- Charles F Reich
- Medical Research Service, 151G Durham VAMC, 508 Fulton Street, Durham, NC 27705, USA
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Li C, Barker SJ, Gilchrist DG, Lincoln JE, Cowling WA. Leptosphaeria maculans elicits apoptosis coincident with leaf lesion formation and hyphal advance in Brassica napus. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2008; 21:1143-53. [PMID: 18700819 DOI: 10.1094/mpmi-21-9-1143] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Programmed cell death, with many of the morphological markers of apoptosis, is increasingly recognized as an important process in plant disease. We have investigated the involvement and potential role of apoptosis during the formation of leaf lesions by the fungus Leptosphaeria maculans on susceptible Brassica napus cv. Westar. There were no signs of host cell damage until 7 to 8 days postinoculation (dpi), when trypan-blue-stained leaf mesophyll cells were first detected. Hyphae were visible in the intercellular spaces of the inoculated area from 5 dpi and were associated with trypan-blue-stained cells at 8 to 9 dpi. Hallmarks of apoptosis, observed coincident with or immediately prior to the formation of leaf lesions at 8 to 10 dpi, included membrane shrinkage of the mesophyll cell cytoplasm, loss of cell to cell contact in mesophyll cells, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling of nuclei in apparently "healthy" tissue immediately adjacent to dead areas. Hyphae were highly branched and prolific in the "healthy" tissue immediately adjacent to dead areas 9 to 10 dpi, and formed pycnidia inside dead areas 11 to 12 dpi. Coinfiltration of the tetrapeptide caspase inhibitor Ac-DEVD-CHO with spores of the pathogen significantly suppressed development of leaf lesions but did not affect fungus viability. We hypothesize that L. maculans elicits apoptosis as a dependent component of pathogenesis in susceptible B. napus, and that the fungus uses apoptotic cells as a source of nutrition for reproduction and further growth.
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Affiliation(s)
- Caixia Li
- School of Plant Biology, The University of Western Australia, Crawley, WA, Australia
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13
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Rippa S, Adenier H, Derbaly M, Béven L. The peptaibol alamethicin induces an rRNA-cleavage-associated death in Arabidopsis thaliana. Chem Biodivers 2007; 4:1360-73. [PMID: 17589869 DOI: 10.1002/cbdv.200790116] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The plant-metabolic response to amphipathic peptides produced by the soil fungi of the genus Trichoderma remains largely unknown. The present investigation was undertaken to examine the death process in alamethicin-treated Arabidopsis thaliana plantlets. The rapid death triggered by alamethicin (at 50 microM) was shown to be associated with protein-synthesis arrest and with specific cleavage of 18S and 25S ribosomal RNA. The use of an inhibitor of nitric oxide (NO) synthases and of an NO scavenger suggested that rRNA cleavage was suppressed by NO. Experiments conducted with a synthetic alamethicin analogue, in which all alpha-aminoisobutyric acid (Aib) residues have been replaced by leucine moieties, showed that the non-coded residues are essential for the ability of the peptaibol to induce rRNA cleavage in Arabidopsis. Our data indicate that further investigations on the mode of action of alamethicin in planta could be of great interest to study the death-signaling pathway associated with rRNA degradation in plants.
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Affiliation(s)
- Sonia Rippa
- Université de Technologie de Compiègne, CNRS, UMR 6022 Génie Enzymatique et Cellulaire, Compiègne Cedex, France
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14
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Kaschani F, van der Hoorn R. Small molecule approaches in plants. Curr Opin Chem Biol 2007; 11:88-98. [PMID: 17208036 DOI: 10.1016/j.cbpa.2006.11.038] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Accepted: 11/28/2006] [Indexed: 12/29/2022]
Abstract
Small molecules offer exciting opportunities for plant science. So far, bioactive small molecules have been identified as plant hormones, herbicides, growth regulators, or taken from animal research. Recently, plant scientists have started to explore further the chemical space for novel modulators of plant hormone signalling, and have followed up this work with exciting discoveries illustrating the potential of small molecules such as brassinazole and sirtinol. New chemical genetic screens have been designed to generate chemical tools for the investigation of membrane trafficking, gravitropism and plant immunity. Further novel 'chemetic' tools to identify targets and modes of action are currently generated through an intimate interdisciplinary collaboration between biologists and small molecule chemists.
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Affiliation(s)
- Farnusch Kaschani
- Plant Chemetics Group, Chemical Genomics Centre, Dortmund, Germany and Max Planck Institute for Plant Breeding Research, Cologne, Germany
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